PHILIPS LUMILEDS LIGHTING COMPANY, LLC Patent applications |
Patent application number | Title | Published |
20140183595 | LIGHT EMITTING DEVICE WITH BONDED INTERFACE - In some embodiments of the invention, a transparent substrate AlInGaP device includes an etch stop layer that may be less absorbing than a conventional etch stop layer. In some embodiments of the invention, a transparent substrate AlInGaP device includes a bonded interface that may be configured to give a lower forward voltage than a conventional bonded interface. Reducing the absorption and/or the forward voltage in a device may improve the efficiency of the device. | 07-03-2014 |
20140034990 | III-V LIGHT EMITTING DEVICE WITH THIN N-TYPE REGION - A device includes a semiconductor structure comprising a III-phosphide light emitting layer disposed between an n-type region and a p-type region. A transparent, conductive oxide is disposed in direct contact with the n-type region. In some embodiments, a total thickness of semiconductor material between the light emitting layer and the transparent, conductive oxide is less than one micron. | 02-06-2014 |
20120319554 | ELECTRIC LAMP HAVING REFLECTOR FOR TRANSFERRING HEAT FROM LIGHT SOURCE - The invention relates to an electric lamp ( | 12-20-2012 |
20120267668 | SEMICONDUCTOR LIGHT EMITTING DEVICE WITH LIGHT EXTRACTION STRUCTURES - Structures are incorporated into a semiconductor light emitting device which may increase the extraction of light emitted at glancing incidence angles. In some embodiments, the device includes a low index material that directs light away from the metal contacts by total internal reflection. In some embodiments, the device includes extraction features such as cavities in the semiconductor structure which may extract glancing angle light directly, or direct the glancing angle light into smaller incidence angles which are more easily extracted from the device. | 10-25-2012 |
20120241798 | III-V LIGHT EMITTING DEVICE INCLUDING A LIGHT EXTRACTING STRUCTURE - Embodiments of the invention include a substrate comprising a host and a seed layer bonded to the host, and a semiconductor structure comprising a light emitting layer disposed between an n-type region and a p-type region grown over the seed layer. A variation in index of refraction in a direction perpendicular to a growth direction of the semiconductor structure is disposed between the host and the light emitting layer. | 09-27-2012 |
20120225505 | METHOD OF BONDING A SEMICONDUCTOR DEVICE USING A COMPLIANT BONDING STRUCTURE - A compliant bonding structure is disposed between a semiconductor device and a mount. In some embodiments, the device is a light emitting device. When the semiconductor light emitting device is attached to the mount, for example by providing ultrasonic energy to the semiconductor light emitting device, the compliant bonding structure collapses to partially fill a space between the semiconductor light emitting device and the mount. In some embodiments, the compliant bonding structure is plurality of metal bumps that undergo plastic deformation during bonding. In some embodiments, the compliant bonding structure is a porous metal layer. | 09-06-2012 |
20120187427 | LAMINATING ENCAPSULANT FILM CONTAINING PHOSPHOR OVER LEDS - A process is described for wavelength conversion of LED light using phosphors. LED dies are tested for correlated color temperature (CCT), and binned according to their color emission. The LEDs in each_bin are mounted on a single submount to form an array of LEDs. Various thin sheets of a flexible encapsulant (e.g., silicone) infused with one or more phosphors are preformed, where each sheet has different color conversion properties. An appropriate sheet is placed over an array of LED mounted on a submount, and the LEDs are energized. The resulting light is measured for CCT. If the CCT is acceptable, the phosphor sheet is permanently laminated onto the LEDs and submount. By selecting a different phosphor sheet for each bin of LEDs, the resulting CCT is very uniform across all bins. | 07-26-2012 |
20120187372 | CONTACT FOR A SEMICONDUCTOR LIGHT EMITTING DEVICE - An AlGaInP light emitting device is formed as a thin, flip chip device. The device includes a semiconductor structure comprising an AlGaInP light emitting layer disposed between an n-type region and a p-type region. N- and p-contacts electrically connected to the n- and p-type regions are both formed on the same side of the semiconductor structure. The semiconductor structure is connected to the mount via the contacts. The growth substrate is removed from the semiconductor structure and the thick transparent substrate is omitted, such that the total thickness of semiconductor layers in the device is less than 15 μm in some embodiments, less than 10 μm in some embodiments. The top side of the semiconductor structure may be textured. | 07-26-2012 |
20120112161 | LIGHT EMITTING DEVICE WITH TRENCHES AND A TOP CONTACT - A device includes a semiconductor structure comprising a light emitting layer disposed between an n-type region and a p-type region. A bottom contact disposed on a bottom surface of the semiconductor structure is electrically connected to one of the n-type region and the p-type region. A top contact disposed on a top surface of the semiconductor structure is electrically connected to the other of the n-type region and the p-type region. A mirror is aligned with the top contact. The mirror includes a trench formed in the semiconductor structure and a reflective material disposed in the trench, wherein the trench extends through the light emitting layer. | 05-10-2012 |
20120045858 | CONTACT FOR A SEMICONDUCTOR LIGHT EMITTING DEVICE - A semiconductor structure includes a light emitting layer disposed between an n-type region and a p-type region. A p-electrode is disposed on a portion of the p-type region. The p-electrode includes a reflective first material in direct contact with a first portion of the p-type region and a second material in direct contact with a second portion of the p-type region adjacent to the first portion. The first material and second material are formed in planar layers of substantially the same thickness. | 02-23-2012 |
20120043564 | COMMON OPTICAL ELEMENT FOR AN ARRAY OF PHOSPHOR CONVERTED LIGHT EMITTING DEVICES - A device is provided with at least one light emitting device (LED) die mounted on a submount with an optical element subsequently thermally bonded to the LED die. The LED die is electrically coupled to the submount through contact bumps that have a higher temperature melting point than is used to thermally bond the optical element to the LED die. In one implementation, a single optical element is bonded to a plurality of LED dice that are mounted to the submount and the submount and the optical element have approximately the same coefficients of thermal expansion. Alternatively, a number of optical elements may be used. The optical element or LED die may be covered with a coating of wavelength converting material. In one implementation, the device is tested to determine the wavelengths produced and additional layers of the wavelength converting material are added until the desired wavelengths are produced. | 02-23-2012 |
20110297979 | PASSIVATION FOR A SEMICONDUCTOR LIGHT EMITTING DEVICE - In embodiments of the invention, a passivation layer is disposed over a side of a semiconductor structure including a light emitting layer disposed between an n-type region and a p-type region. A material configured to adhere to an underfill is disposed over an etched surface of the semiconductor structure. | 12-08-2011 |
20110291113 | FILTER FOR A LIGHT EMITTING DEVICE - Embodiments of the invention include a semiconductor light emitting device capable of emitting first light having a first peak wavelength and a wavelength converting element capable of absorbing the first light and emitting second light having a second peak wavelength. In some embodiments, the structure further includes a metal nanoparticle array configured to pass a majority of light in a first wavelength range and reflect or absorb a majority of light in a second wavelength range. In some embodiments, the structure further includes a filter configured to pass a majority of light in a first wavelength range and reflect or absorb a majority of light in a second wavelength range, wherein the filter is configured such that a wavelength at which a minimum amount of light is passed by the filter shifts no more than 30 nm for light incident on the filter at angles between 0° and 60° relative to a normal to a major surface of the filter. | 12-01-2011 |
20110284993 | COMPOSITE GROWTH SUBSTRATE FOR GROWING SIMICONDUCTOR DEVICE - A method according to embodiments of the invention includes providing an epitaxial structure comprising a donor layer and a strained layer. The epitaxial structure is treated to cause the strained layer to relax. Relaxation of the strained layer causes an in-plane lattice constant of the donor layer to change. | 11-24-2011 |
20110284890 | LIGHT EMITTING DEVICE GROWN ON A RELAXED LAYER - In some embodiments of the invention, a device includes a first semiconductor layer, a second semiconductor layer, a third semiconductor layer, and a semiconductor structure comprising a III-nitride light emitting layer disposed between an n-type region and a p-type region. The second semiconductor layer is disposed between the first semiconductor layer and the third semiconductor layer. The third semiconductor layer is disposed between the second semiconductor layer and the light emitting layer. A difference between the in-plane lattice constant of the first semiconductor layer and the bulk lattice constant of the third semiconductor layer is no more than 1%. A difference between the in-plane lattice constant of the first semiconductor layer and the bulk lattice constant of the second semiconductor layer is at least 1%. The third semiconductor layer is at least partially relaxed. | 11-24-2011 |
20110272721 | LED PACKAGE WITH A ROUNDED SQUARE LENS - A rounded square lens is used instead of a hemispherical lens in an LED package to produce a substantially Lambertian light emission pattern. A cross-sectional view of the rounded square lens cut along its diagonal forms a semicircular surface so as to emulate a hemispherical lens in areas close to the diagonal. A cross-sectional view of the lens cut along its width bisecting the lens forms a bullet shaped surface narrower than the semicircular surface but having the same height as the semicircular surface. The four corners of the lens are rounded. The surface of the lens smoothly transitions between the two surface shapes. Since the rounded square lens has a diagonal dimension larger than a maximum allowable diameter of a hemispherical lens in the same package body, a larger LED die may be used with the rounded square lens to output more light without increasing the size of the package while maintaining a Lambertian emission. | 11-10-2011 |
20110266569 | LED WAFER WITH LAMINATED PHOSPHOR LAYER - An LED wafer with a growth substrate is attached to a carrier substrate by, for example, a heat-releasable adhesive so that the LED layers are sandwiched between the two substrates. The growth substrate is then removed, such as by laser lift-off. The exposed surface of the LED layers is then etched to improve light extraction. A preformed phosphor sheet, matched to the LEDs, is then affixed to the exposed LED layer. The phosphor sheet, LED layers, and, optionally, the carrier substrate are then diced to separate the LEDs. The LED dice are released from the carrier substrate by heat or other means, and the individual LED dice are mounted on a submount wafer using a pick-and-place machine. The submount wafer is then diced to produce individual LEDs. The active layer may generate blue light, and the blue light and phosphor light may generate white light having a predefined white point. | 11-03-2011 |
20110266568 | LIGHT EMITTING DEVICE WITH TRENCHES AND A TOP CONTACT - A device includes a semiconductor structure comprising a light emitting layer disposed between an n-type region and a p-type region. A bottom contact disposed on a bottom surface of the semiconductor structure is electrically connected to one of the n-type region and the p-type region. A top contact disposed on a top surface of the semiconductor structure is electrically connected to the other of the n-type region and the p-type region. A mirror is aligned with the top contact. The mirror includes a trench formed in the semiconductor structure and a reflective material disposed in the trench, wherein the trench extends through the light emitting layer. | 11-03-2011 |
20110260178 | LIGHTING SYSTEM INCLUDING COLLIMATORS ALIGNED WITH LIGHT EMITTING SEGMENTS - A light source comprising a semiconductor light emitting device is connected to a mount. The light emitting device comprises a plurality of segments with neighboring segments spaced less than 200 microns apart. In some embodiments, multiple segments are grown on a single growth substrate. Each segment comprises a light emitting layer disposed between an n-type region and a p-type region. A spacer is positioned on a top surface of the mount. The light emitting device is positioned in an opening in the spacer. A plurality of collimators is attached to the spacer, wherein each collimator is aligned with a single segment. | 10-27-2011 |
20110241056 | SEMICONDUCTOR LIGHT EMITTING DEVICE WITH LIGHT EXTRACTION STRUCTURES - Structures are incorporated into a semiconductor light emitting device which may increase the extraction of light emitted at glancing incidence angles. In some embodiments, the device includes a low index material that directs light away from the metal contacts by total internal reflection. In some embodiments, the device includes extraction features such as cavities in the semiconductor structure which may extract glancing angle light directly, or direct the glancing angle light into smaller incidence angles which are more easily extracted from the device. | 10-06-2011 |
20110233580 | CARRIER FOR A LIGHT EMITTING DEVICE - A semiconductor light emitting device is mounted on a support substrate. The support substrate is disposed in an opening in a carrier. In some embodiments, the support substrate is a ceramic tile and the carrier is a low cost material with a lateral extent large enough to support a lens molded over or attached to the carrier. | 09-29-2011 |
20110223696 | UNDERFILL PROCESS FOR FLIP-CHIP LEDS - An underfill technique for LEDs uses compression molding to simultaneously encapsulate an array of flip-chip LED dies mounted on a submount wafer. The molding process causes liquid underfill material (or a softened underfill material) to fill the gap between the LED dies and the submount wafer. The underfill material is then hardened, such as by curing. The cured underfill material over the top and sides of the LED dies is removed using microbead blasting. The exposed growth substrate is then removed from all the LED dies by laser lift-off, and the underfill supports the brittle epitaxial layers of each LED die during the lift-off process. The submount wafer is then singulated. This wafer-level processing of many LEDs simultaneously greatly reduces fabrication time, and a wide variety of materials may be used for the underfill since a wide range of viscosities is tolerable. | 09-15-2011 |
20110205049 | ADAPTIVE LIGHTING SYSTEM WITH III-NITRIDE LIGHT EMITTING DEVICES - A device includes a light source, a sensor, and a controller. The light source includes at least one light emitting device connected to a mount. The light emitting device comprises a plurality of segments with neighboring segments spaced less than 200 microns apart. In some embodiments, the plurality of segments are grown on a single growth substrate. Each segment includes a III-nitride light emitting layer disposed between an n-type region and a p-type region. The mount is configured such that at least two segments may be independently activated. The controller is coupled between the sensor and the mount. The controller is operable to receive an input from the sensor and based on the input, selectively illuminate at least one segment in the light source. | 08-25-2011 |
20110198780 | LIGHT EMITTING DEVICE WITH MOLDED WAVELENGTH CONVERTING LAYER - A flexible film comprising a wavelength converting material is positioned over a light source. The flexible film is conformed to a predetermined shape. In some embodiments, the light source is a light emitting diode mounted on a support substrate. The diode is aligned with an indentation in a mold such that the flexible film is disposed between the support substrate and the mold. Transparent molding material is disposed between the support substrate and the mold. The support substrate and the mold are pressed together to cause the molding material to fill the indentation. The flexible film conforms to the shape of the light source or the mold. | 08-18-2011 |
20110195583 | WAVELENGTH CONVERTING LAYER FOR A LIGHT EMITTING DEVICE - A layer of wavelength converting material is formed by supplying energy to a particle of wavelength converting material and causing the particle to contact a surface such that the energy causes the particle to adhere to the surface. In some embodiments, the wavelength converting material is a phosphor and the surface is a surface of a semiconductor light emitting device. | 08-11-2011 |
20110177638 | SEMICONDUCTOR LIGHT EMITTING DEVICE WITH CURVATURE CONTROL LAYER - A semiconductor structure is grown on a top surface of a growth substrate. The semiconductor structure comprises a III-nitride light emitting layer disposed between an n-type region and a p-type region. A curvature control layer is disposed in direct contact with the growth substrate. The growth substrate has a thermal expansion coefficient less than a thermal expansion coefficient of GaN and the curvature control layer has a thermal expansion coefficient greater than the thermal expansion coefficient of GaN. | 07-21-2011 |
20110177631 | METHOD OF FORMING A COMPOSITE SUBSTRATE AND GROWING A III-V LIGHT EMITTING DEVICE OVER THE COMPOSITE SUBSTRATE - A method according to embodiments of the invention includes providing a substrate comprising a host and a seed layer bonded to the host. The seed layer comprises a plurality of regions. A semiconductor structure comprising a light emitting layer disposed between an n-type region and a p-type region is grown on the substrate. A top surface of a semiconductor layer grown on the seed layer has a lateral extent greater than each of the plurality of seed layer regions. | 07-21-2011 |
20110175138 | SEMICONDUCTOR LIGHT EMITTING DEVICE WITH INTEGRATED ELECTRONIC COMPONENTS - One or more circuit elements such as silicon diodes, resistors, capacitors, and inductors are disposed between the semiconductor structure of a semiconductor light emitting device and the connection layers used to connect the device to an external structure. In some embodiments, the n-contacts to the semiconductor structure are distributed across multiple vias, which are isolated from the p-contacts by one or more dielectric layers. The circuit elements are formed in the contacts-dielectric layers-connection layers stack. | 07-21-2011 |
20110175112 | III-V LIGHT EMITTING DEVICE INCLUDING A LIGHT EXTRACTING STRUCTURE - Embodiments of the invention include a substrate comprising a host and a seed layer bonded to the host, and a semiconductor structure comprising a light emitting layer disposed between an n-type region and a p-type region grown over the seed layer. A variation in index of refraction in a direction perpendicular to a growth direction of the semiconductor structure is disposed between the host and the light emitting layer. | 07-21-2011 |
20110156056 | WAVELENGTH-CONVERTED SEMICONDUCTOR LIGHT EMITTING DEVICE - A material such as a phosphor is optically coupled to a semiconductor structure including a light emitting region disposed between an n-type region and a p-type region, in order to efficiently extract light from the light emitting region into the phosphor. The phosphor may be phosphor grains in direct contact with a surface of the semiconductor structure, or a ceramic phosphor bonded to the semiconductor structure, or to a thin nucleation structure on which the semiconductor structure may be grown. The phosphor is preferably highly absorbent and highly efficient. When the semiconductor structure emits light into such a highly efficient, highly absorbent phosphor, the phosphor may efficiently extract light from the structure, reducing the optical losses present in prior art devices. | 06-30-2011 |
20110136273 | REFLECTIVE CONTACT FOR A SEMICONDUCTOR LIGHT EMITTING DEVICE - A light emitting device includes a semiconductor structure comprising a light emitting layer disposed between an n-type region and a p-type region. A contact is formed on the semiconductor structure, the contact comprising a reflective metal in direct contact with the semiconductor structure and an additional metal or semi-metal disposed within the reflective metal. In some embodiments, the additional metal or semi-metal is a material with higher electronegativity than the reflective metal. The presence of the high electronegativity material in the contact may increase the overall electronegativity of the contact, which may reduce the forward voltage of the device. In some embodiments, an oxygen-gathering material is included in the contact. | 06-09-2011 |
20110132521 | COLOR CONTROL BY ALTERATION OF WAVELENGTH CONVERTING ELEMENT - A light emitting device is produced by depositing a layer of wavelength converting material over the light emitting device, testing the device to determine the wavelength spectrum produced and correcting the wavelength converting member to produce the desired wavelength spectrum. The wavelength converting member may be corrected by reducing or increasing the amount of wavelength converting material. In one embodiment, the amount of wavelength converting material in the wavelength converting member is reduced, e.g., through laser ablation or etching, to produce the desired wavelength spectrum. | 06-09-2011 |
20110121758 | TUNABLE WHITE POINT LIGHT SOURCE USING A WAVELENGTH CONVERTING ELEMENT - A uniform high brightness light source is provided using a plurality of light emitting diode (LED) chips with slightly different pump wavelengths with a wavelength converting element that includes at least two different wavelength converting materials that convert the light to different colors of light. The intensity of the light produced by the LED chips may be varied to provide a tunable CCT white point. The wavelength converting element may be, e.g., a stack or mixture of phosphor or luminescent ceramics. Moreover, the manufacturing process of the light source is simplified because the LED chips are all manufactured using the same technology eliminating the need to manufacture different types of chips. | 05-26-2011 |
20110121358 | P-TYPE LAYER FOR A III-NITRIDE LIGHT EMITTING DEVICE - A semiconductor structure includes a light emitting region, a p-type region disposed on a first side of the light emitting region, and an n-type region disposed on a second side of the light emitting region. At least 10% of a thickness of the semiconductor structure on the first side of the light emitting region comprises indium. Some examples of such a semiconductor light emitting device may be formed by growing an n-type region, growing a p-type region, and growing a light emitting layer disposed between the n-type region and the p-type region. The difference in temperature between the growth temperature of a part of the n-type region and the growth temperature of a part of the p-type region is at least 140° C. | 05-26-2011 |
20110121332 | III-V LIGHT EMITTING DEVICE WITH THIN N-TYPE REGION - A device includes a semiconductor structure comprising a III-nitride light emitting layer disposed between an n-type region and a p-type region. A transparent, conductive non-III-nitride material is disposed in direct contact with the n-type region. A total thickness of semiconductor material between the light emitting layer and the transparent, conductive non-III-nitride material is less than one micron. | 05-26-2011 |
20110121331 | WAVELENGTH CONVERTED SEMICONDUCTOR LIGHT EMITTING DEVICE - A device includes a semiconductor structure comprising a light emitting layer disposed between an n-type region and a p-type region. A luminescent material is positioned in a path of light emitted by the light emitting layer. A thermal coupling material is disposed in a transparent material. The thermal coupling material has a thermal conductivity greater than a thermal conductivity of the transparent material. The thermal coupling material is positioned to dissipate heat from the luminescent material. | 05-26-2011 |
20110108865 | SILICONE BASED REFLECTIVE UNDERFILL AND THERMAL COUPLER - In one embodiment, a flip chip LED is formed with a high density of gold posts extending from a bottom surface of its n-layer and p-layer. The gold posts are bonded to submount electrodes. An underfill material is then molded to fill the voids between the bottom of the LED and the submount. The underfill comprises a silicone molding compound base and about 70-80%, by weight, alumina (or other suitable material). Alumina has a thermal conductance that is about 25 times better than that of the typical silicone underfill, which is mostly silica. The alumina is a white powder. The underfill may also contain about 5-10%, by weight, TiO | 05-12-2011 |
20110097833 | LIGHT SOURCE INCLUDING A WAVELENGHT-CONVERETED SEMICONDUCTOR LIGHT EMITTING DEVICE AND A FILTER - A semiconductor light emitting device comprises a light emitting layer disposed between an n-type region and a p-type region. The light emitting layer is adapted to emit first light having a first peak wavelength. A first wavelength converting material is adapted to absorb the first light and emit second light having a second peak wavelength. A second wavelength converting material is adapted to absorb either the first light or the second light and emit third light having a third peak wavelength. A filter is adapted to reflect fourth light having a fourth peak wavelength. The fourth light is either a portion of the second light or a portion of the third light. The filter is configured to transmit light having a peak wavelength longer or shorter than the fourth peak wavelength. The filter is disposed over the light emitting device in the path of at least a portion of the first, second, and third light. | 04-28-2011 |
20110062472 | WAVELENGTH-CONVERTED SEMICONDUCTOR LIGHT EMITTING DEVICE - A light emitting diode includes a semiconductor structure comprising a light emitting layer disposed between an n-type region and a p-type region, and n- and p-contacts disposed on the n- and p-type regions. The light emitting layer is configured to emit light of a first peak wavelength. A wavelength converting material is positioned in a path of light emitted by the light emitting layer. The wavelength converting material is configured to absorb light of the first peak wavelength and emit light of a second peak wavelength. The light emitting diode is configured such that a light emission pattern from the light emitting diode complements a light emission pattern from the wavelength converting material. | 03-17-2011 |
20110062471 | LED MODULE WITH HIGH INDEX LENS - An array of housings with housing bodies and lenses is molded, or an array of housing bodies is molded and bonded with lenses to form an array of housings with housing bodies and lenses. Light-emitting diodes (LEDs) are attached to the housings in the array. An array of metal pads may be bonded to the back of the array or insert molded with the housing array to form bond pads on the back of the housings. The array is singulated to form individual LED modules. | 03-17-2011 |
20110062470 | REDUCED ANGULAR EMISSION CONE ILLUMINATION LEDS - A light emitting diode (LED) package includes a support, an LED die mounted on the support, a reflector around the LED die, and a lens over the LED die. The reflector has an angled reflective surface that limits the light emission angle from the LED package. The reflector is a part of the lens or the support. | 03-17-2011 |
20110062469 | MOLDED LENS INCORPORATING A WINDOW ELEMENT - A light emitter includes a light-emitting device (LED) die and an optical element over the LED die. The optical element includes a lens, a window element, and a bond at an interface disposed between the lens and the window element. The window element may be a wavelength converting element or an optically flat plate. The window element may be directly bonded or fused to the lens, or the window element may be bonded by one or more intermediate bonding layers to the lens. The bond between the window element and the lens may have a refractive index similar to that of the window element, the lens, or both. | 03-17-2011 |
20110062468 | PHOSPHOR-CONVERTED LIGHT EMITTING DIODE DEVICE - A light emitting diode is provided which is capable of emitting a first light having a first peak wavelength. The light emitting diode is provided with a phosphor layer overlying the light emitting diode and capable of absorbing the first light and emitting a second light having a second peak wavelength. The phosphor layer includes a pattern of holes positioned to allow the first peak wavelength to exit through the holes without being absorbed by the phosphor layer, and wherein the holes are placed to facilitate more of the first peak wavelength to exit the phosphor in the area of the holes than the second peak wavelength. | 03-17-2011 |
20110057569 | ZENER DIODE PROTECTION NETWORK IN SUBMOUNT FOR LEDS CONNECTED IN SERIES - A transient voltage suppressor circuit is disclosed for a plurality (N) of LEDs connected in series. Only one zener diode is created for connection to each node between LEDs, and a pair of zener diodes (the “end” zener diodes) are connected to the two pins (anode and cathode pads) of the series string. Therefore, only N+1 zener diodes are used. The end zener diodes (Q | 03-10-2011 |
20110057213 | III-NITRIDE LIGHT EMITTING DEVICE WITH CURVAT1JRE CONTROL LAYER - A semiconductor structure comprises a III-nitride light emitting layer disposed between an n-type region and a p-type region. The semiconductor structure further comprises a curvature control layer grown on a first layer. The curvature control layer is disposed between the n-type region and the first layer. The curvature control layer has a theoretical a-lattice constant less than the theoretical a-lattice constant of GaN. The first layer is a substantially single crystal layer. | 03-10-2011 |
20110049545 | LED PACKAGE WITH PHOSPHOR PLATE AND REFLECTIVE SUBSTRATE - After flip chip LEDs are mounted on a submount wafer and their growth substrates removed, a phosphor plate is affixed to the exposed top surface of each LED. A reflective material, such as silicone containing at least 5% TiO | 03-03-2011 |
20110031516 | LED WITH SILICONE LAYER AND LAMINATED REMOTE PHOSPHOR LAYER - A method for fabricating a light emitting device is described where an array of flip-chip light emitting diode (LED) dies are mounted on a submount wafer. Over each of the LED dies is simultaneously molded a hemispherical first silicone layer. A preformed flexible phosphor layer, comprising phosphor powder infused in silicone, is laminated over the first silicone layer to conform to the outer surface of the hemispherical first silicone layer. A silicone lens is then molded over the phosphor layer. By preforming the phosphor layer, the phosphor layer may be made to very tight tolerances and tested. By separating the phosphor layer from the LED die by a molded hemispherical silicone layer, color vs. viewing angle is constant, and the phosphor is not degraded by heat. The flexible phosphor layer may comprise a plurality of different phosphor layers and may comprise a reflector or other layers. | 02-10-2011 |
20110018017 | LED WITH MOLDED REFLECTIVE SIDEWALL COATING - A submount wafer, having mounted on it an array of LEDs with a phosphor layer, is positioned with respect to a mold having an array of indentions. A mixture of silicone and 10%-50%, by weight, TiO | 01-27-2011 |
20110018016 | REDUCED COLOR OVER ANGLE VARIATION LEDS - A light emitting diode (LED) package includes an LED die includes a stack of semiconductor layers including an active region, and a wavelength converting element over the LED die. The wavelength converting element includes two or more non-flat surfaces that produce a desired angular color distribution pattern. | 01-27-2011 |
20110018015 | CONTACT FOR A SEMICONDUCTOR LIGHT EMITTING DEVICE - A semiconductor structure includes a light emitting layer disposed between an n-type region and a p-type region. A p-electrode is disposed on a portion of the p-type region. The p-electrode includes a reflective first material in direct contact with a first portion of the p-type region and a second material in direct contact with a second portion of the p-type region adjacent to the first portion. The first material and second material are formed in planar layers of substantially the same thickness. | 01-27-2011 |
20110018013 | THIN-FILM FLIP-CHIP SERIES CONNECTED LEDS - A light-emitting diode (LED) is fabricated by forming the LED segments with bond pads covering greater than 85% of a mounting surface of the LED segments and isolation trenches that electrically isolate the LED segments, mounting the LED segments on a submount with a bond pad that couples two or more bond pads from the LED segments, and applying a laser lift-off to remove the growth substrate from the LED layer. | 01-27-2011 |
20110012149 | REFLECTIVE SUBSTRATEFOR LEDS - An underfill formation technique for LEDs molds a reflective underfill material to encapsulate LED dies mounted on a submount wafer while forming a reflective layer of the underfill material over the submount wafer. The underfill material is then hardened, such as by curing. The cured underfill material over the top of the LED dies is removed using microbead blasting while leaving the reflective layer over the submount surface. The exposed growth substrate is then removed from all the LED dies, and a phosphor layer is molded over the exposed LED surface. A lens is then molded over the LEDs and over a portion of the reflective layer. The submount wafer is then singulated. The reflective layer increases the efficiency of the LED device by reducing light absorption by the submount without any additional processing steps. | 01-20-2011 |
20110012148 | LIGHTING DEVICE WITH LIGHT SOURCES POSITIONED NEAR THE BOTTOM SURFACE OF A WAVEGUIDE - A device according to embodiments of the invention includes a waveguide, typically formed from a first section of transparent material. A light source is disposed proximate a bottom surface of the waveguide. The light source comprises a semiconductor light emitting diode and a second section of transparent material disposed between the semiconductor light emitting diode and the waveguide. Sidewalls of the second section of transparent material are reflective. A surface to be illuminated is disposed proximate a top surface of the waveguide. In some embodiments, an edge of the waveguide is curved. | 01-20-2011 |
20110012147 | WAVELENGTH-CONVERTED SEMICONDUCTOR LIGHT EMITTING DEVICE INCLUDING A FILTER AND A SCATTERING STRUCTURE - A semiconductor structure comprises a light emitting layer disposed between an n-type region and a p-type region. A wavelength converting material is disposed over the semiconductor structure. The wavelength converting material is configured to absorb light emitted by the semiconductor structure and emit light of a different wavelength. A filter configured to reflect blue ambient light is disposed over the wavelength converting material. A scattering structure is disposed over the wavelength converting layer. The scattering structure is configured to scatter light. In some embodiments, the scattering structure is a transparent material having a rough surface, containing non-wavelength-converting particles that appear substantially white in ambient light, or including both a rough surface and white particles. | 01-20-2011 |
20100327300 | CONTACT FOR A SEMICONDUCTOR LIGHT EMITTING DEVICE - Embodiments of the invention include a semiconductor structure comprising a III-nitride light emitting layer disposed between an n-type region and a p-type region. A contact disposed on the p-type region includes a transparent conductive material in direct contact with the p-type region, a reflective metal layer, and a transparent insulating material disposed between the transparent conductive layer and the reflective metal layer. In a plurality of openings in the transparent insulating material, the transparent conductive material is in direct contact with the reflective metal layer. | 12-30-2010 |
20100327299 | P-CONTACT LAYER FOR A III-P SEMICONDUCTOR LIGHT EMITTING DEVICE - A device includes a semiconductor structure with at least one III-P light emitting layer disposed between an n-type region and a p-type region. The semiconductor structure further includes a GaAs | 12-30-2010 |
20100327256 | CONTROLLING PIT FORMATION IN A III-NITRIDE DEVICE - A device includes a semiconductor structure comprising a III-nitride light emitting layer disposed between an n-type region and a p-type region and a plurality of layer pairs disposed within one of the n-type region and the p-type region. Each layer pair includes an InGaN layer and pit-filling layer in direct contact with the InGaN layer. The pit-filling layer may fill in pits formed in the InGaN layer. | 12-30-2010 |
20100320489 | SEMICONDUCTOR LIGHT EMITTING DEVICE WITH A CONTACT FORMED ON A TEXTURED SURFACE - A device includes a semiconductor structure comprising a light emitting layer disposed between an n-type region and a p-type region. The semiconductor structure includes an n-contact region and a p-contact region. A cross section of the n-contact region comprises a plurality of first regions wherein portions of the light emitting layer and p-type region are removed to expose the n-type region. The plurality of first regions are separated by a plurality of second regions wherein the light emitting layer and p-type region remain in the device. The device further includes a first metal contact formed over the semiconductor structure in the p-contact region and a second metal contact formed over the semiconductor structure in the n-contact region. The second metal contact is in electrical contact with at least one of the second regions in the n-contact region. | 12-23-2010 |
20100308367 | METHOD OF FORMING A DIELECTRIC LAYER ON A SEMICONDUCTOR LIGHT EMITTING DEVICE - A semiconductor structure comprising a light emitting layer disposed between an n-type region and a p-type region is formed. A first metal contact is formed on a portion of the n-type region and a second metal contact is formed on a portion of the p-type region. The first and second metal contacts are formed on a same side of the semiconductor structure. A dielectric material is disposed between the first and second metal contacts. The dielectric material is in direct contact with a portion of the semiconductor structure, a portion of the first metal contact, and a portion of the second metal contact. A planar surface is formed including a surface of the first metal contact, a surface of the second metal contact, and a surface of the dielectric material | 12-09-2010 |
20100308354 | LED WITH REMOTE PHOSPHOR LAYER AND REFLECTIVE SUBMOUNT - A light emitting device comprises a flip-chip light emitting diode (LED) die mounted on a submount. The top surface of the submount has a reflective layer. Over the LED die is molded a hemispherical first transparent layer. A low index of refraction layer is then provided over the first transparent layer to provide TIR of phosphor light. A hemispherical phosphor layer is then provided over the low index layer. A lens is then molded over the phosphor layer. The reflection achieved by the reflective submount layer, combined with the TIR at the interface of the high index phosphor layer and the underlying low index layer, greatly improves the efficiency of the lamp. Other material may be used. The low index layer may be an air gap or a molded layer. Instead of a low index layer, a distributed Bragg reflector may be sputtered over the first transparent layer. | 12-09-2010 |
20100295090 | MOUNT FOR A SEMICONDUCTOR LIGHT EMITTING DEVICE - A mount for a semiconductor device includes a carrier, at least two metal leads disposed on a bottom surface of the carrier, and a cavity extending through a thickness of the carrier to expose a portion of the top surfaces of the metal leads. A semiconductor light emitting device is positioned in the cavity and is electrically and physically connected to the metal leads. The carrier may be, for example, silicon, and the leads may be multilayer structures, for example a thin gold layer connected to a thick copper layer. | 11-25-2010 |
20100290234 | LED LAMP PRODUCING SPARKLE - A substantially hemispherical lens surrounding an LED die is described that creates a sparkle as an observer views the lens from different angles. The lens is formed of an interconnected array of 100-10,000 or more lenslets. Each lenslet focuses an image of the LED die at an output of the lenslet such that the LED die image area at the output is less than 1/9 the area of the LED die to create a substantially point source image of the LED die at an outer surface of the lens. When the LED die is energized, the shape of each lenslet causes point source images of the LED die to be perceived by an observer at various viewing angles, such that the emitted LED light appears to sparkle and speckle as the observer moves relative to the lens. | 11-18-2010 |
20100289044 | WAVELENGTH CONVERSION FOR PRODUCING WHITE LIGHT FROM HIGH POWER BLUE LED - A white light LED is described that uses an LED die that emits visible blue light in a wavelength range of about 450-470 nm. A red phosphor or quantum dot material converts some of the blue light to a visible red light having a peak wavelength between about 605-625 nm with a full-width-half-maximum (FWHM) less than 80 nm. A green phosphor or quantum dot material converts some of the blue light to a green light having a FWHM greater than 40 nm, wherein the combination of the blue light, red light, and green light produces a white light providing a color rendering of R | 11-18-2010 |
20100283080 | EXTENSION OF CONTACT PADS TO THE DIE EDGE VIA ELECTRICAL ISOLATION - Light emitting diode (LED) dies are fabricated by forming LED layers including a first conductivity type layer, a light-emitting layer, and a second conductivity type layer. Trenches are formed in the LED layers that reach at least partially into the first conductivity type layer. Electrically insulation regions are formed in or next to at least portions of the first conductivity type layer along the die edges. A first conductivity bond pad layer is formed to electrically contact the first conductivity type layer and extend over the singulation streets between the LED dies. A second conductivity bond pad layer is formed to electrically contact the second conductivity type layer, and extend over the singulation streets between the LED dies and the electrically insulated portions of the first conductivity type layer. The LED dies are mounted to submounts and the LED dies are singulated along the singulation streets between the LED dies. | 11-11-2010 |
20100279437 | CONTROLLING EDGE EMISSION IN PACKAGE-FREE LED DIE - Light emitting diode (LED) structures are fabricated in wafer scale by mounting singulated LED dies on a carrier wafer or a stretch film, separating the LED dies to create spaces between the LED dies, applying a reflective coating over the LED dies and in the spaces between the LED dies, and separating or breaking the reflective coating in the spaces between the LED dies such that some reflective coating remains on the lateral sides of the LED die. Portions of the reflective coating on the lateral sides of the LED dies may help to control edge emission. | 11-04-2010 |
20100277950 | REMOTE WAVELENGTH CONVERTING MATERIAL CONFIGURATION FOR LIGHTING - A device includes a reflector and a wavelength converting material disposed on the reflector. A backlight is disposed between the reflector and a surface to be illuminated, such as a liquid crystal display panel. The backlight includes a light source and a waveguide. The waveguide is configured to direct a majority of light from the light source toward the reflector. At least a portion of the light is converted by the wavelength converted material, reflected by the reflector, and incident on the surface to be illuminated. | 11-04-2010 |
20100264454 | SEMICONDUCTOR LIGHT EMITTING DEVICE GROWING ACTIVE LAYER ON TEXTURED SURFACE - In accordance with embodiments of the invention, at least partial strain relief in a light emitting layer of a III-nitride light emitting device is provided by configuring the surface on which at least one layer of the device grows such that the layer expands laterally and thus at least partially relaxes. This layer is referred to as the strain-relieved layer. In some embodiments, the light emitting layer itself is the strain-relieved layer, meaning that the light emitting layer is grown on a surface that allows the light emitting layer to expand laterally to relieve strain. In some embodiments, a layer grown before the light emitting layer is the strain-relieved layer. In a first group of embodiments, the strain-relieved layer is grown on a textured surface. | 10-21-2010 |
20100252846 | BACKLIGHT INCLUDING SEMICONDUCTIOR LIGHT EMITTING DEVICES - A light source such as a semiconductor light emitting diode is positioned in a first opening in a transparent member, which may function as a waveguide in a display. The transparent member surrounds the light source. No light source is positioned in a second opening in the transparent member. In some embodiments, the first opening is shaped to direct light into the transparent member. In some embodiments, a reflector is positioned over the light source. The reflector includes a flat portion and a shaped portion. The shaped portion extends from the flat portion toward the light source. | 10-07-2010 |
20100244065 | SEMICONDUCTOR LIGHT EMITTING DEVICE GROWN ON AN ETCHABLE SUBSTRATE - A III-nitride structure comprising a light emitting layer disposed between an n-type region and a p-type region is grown on a silicon substrate. The III-nitride structure is attached to a host, then a portion of the silicon substrate is etched away to reveal a top surface of the III-nitride structure. In some embodiments, the silicon substrate is etched to form an enclosure on the top surface of the III-nitride structure. A wavelength converting material such as phosphor may be disposed in the enclosure. | 09-30-2010 |
20100207157 | LED ASSEMBLY HAVING MAXIMUM METAL SUPPORT FOR LASER LIFT-OFF OF GROWTH SUBSTRATE - Described is a process for forming an LED structure using a laser lift-off process to remove the growth substrate (e.g., sapphire) after the LED die is bonded to a submount. The underside of the LED die has formed on it anode and cathode electrodes that are substantially in the same plane, where the electrodes cover at least 85% of the back surface of the LED structure. The submount has a corresponding layout of anode and cathode electrodes substantially in the same plane. The LED die electrodes and submount electrodes are ultrasonically welded together such that virtually the entire surface of the LED die is supported by the electrodes and submount. Other bonding techniques may also be used. No underfill is used. The growth substrate, forming the top of the LED structure, is then removed from the LED layers using a laser lift-off process. The extremely high pressures created during the laser lift-off process do not damage the LED layers due to the large area support of the LED layers by the electrodes and submount. | 08-19-2010 |
20100148151 | LIGHT EMITTING DEVICES WITH IMPROVED LIGHT EXTRACTION EFFICIENCY - A device includes a light emitting structure and a wavelength conversion member comprising a semiconductor. The light emitting structure is bonded to the wavelength conversion member. In some embodiments, the light emitting structure is bonded to the wavelength conversion member with an inorganic bonding material. In some embodiments, the light emitting structure is bonded to the wavelength conversion member with a bonding material having an index of refraction greater than 1.5. | 06-17-2010 |
20100109568 | COMMON OPTICAL ELEMENT FOR AN ARRAY OF PHOSPHOR CONVERTED LLIGHT EMITTING DEVICES - A device is provided with an array of a plurality of phosphor converted light emitting devices (LEDs) that produce broad spectrum light. The phosphor converted LEDs may produce light with different correlated color temperature (CCT) and are covered with an optical element that assists in mixing the light from the LEDs to produce a desired correlated color temperature. The optical element may be bonded to the phosphor converted light emitting devices. The optical element may be a dome mounted over the phosphor converted light emitting devices and filled with an encapsulant. | 05-06-2010 |
20100109034 | LED WITH MOLDED BI-DIRECTIONAL OPTICS - A double-molded lens for an LED includes an outer lens molded around the periphery of an LED die and a collimating inner lens molded over the top surface of the LED die and partially defined by a central opening in the outer lens. The outer lens is formed using silicone having a relatively low index of refraction such as n=1.33-1.47, and the inner lens is formed of a higher index silicone, such as n=1.54-1.76, to cause TIR within the inner lens. Light not internally reflected by the inner lens is transmitted into the outer lens. The shape of the outer lens determines the side emission pattern of the light. The front and side emission patterns separately created by the two lenses may be tailored for a particular backlight or automotive application. | 05-06-2010 |
20100109030 | SERIES CONNECTED FLIP CHIP LEDS WITH GROWTH SUBSTRATE REMOVED - LED layers are grown over a sapphire substrate. Individual flip chip LEDs are formed by trenching or masked ion implantation. Modules containing a plurality of LEDs are diced and mounted on a submount wafer. A submount metal pattern or a metal pattern formed on the LEDs connects the LEDs in a module in series. The growth substrate is then removed, such as by laser lift-off. A semi-insulating layer is formed, prior to or after mounting, that mechanically connects the LEDs together. The semi-insulating layer may be formed by ion implantation of a layer between the substrate and the LED layers. PEC etching of the semi-insulating layer, exposed after substrate removal, may be performed by biasing the semi-insulating layer. The submount is then diced to create LED modules containing series-connected LEDs. | 05-06-2010 |
20100109025 | OVER THE MOLD PHOSPHOR LENS FOR AN LED - Rectangular LED dice are mounted on a submount wafer. A first mold has rectangular indentations in it generally corresponding to the positions of the LED dice on the submount wafer. The indentations are filled with silicone, which when cured forms a clear first lens over each LED. Since the wafer is precisely aligned with the mold, the top surfaces of the first lenses are all within a single reference plane irrespective of any x, y, and z misalignments of the LEDs on the wafer. A second mold has rectangular indentations filled with a phosphor-infused silicone so as to form a precisely defined phosphor layer over the clear first lens, whose inner and outer surfaces are completely independent of any misalignments of the LEDs. A third mold forms an outer silicone lens. The resulting PC-LEDs have high chromaticity uniformity from PC-LED to PC LED within a submount wafer and from wafer to wafer, and high color uniformity over a wide viewing angle. | 05-06-2010 |
20100051974 | Light Source Including a Wavelength-Converted Semiconductor Light Emitting Device and a Filter - A semiconductor light emitting device comprises a light emitting layer disposed between an n-type region and a p-type region. The light emitting layer is adapted to emit first light having a first peak wavelength. A first wavelength converting material is adapted to absorb the first light and emit second light having a second peak wavelength. A second wavelength converting material is adapted to absorb either the first light or the second light and emit third light having a third peak wavelength. A filter is adapted to reflect fourth light having a fourth peak wavelength. The fourth light is either a portion of the second light or a portion of the third light. The filter is configured to transmit light having a peak wavelength longer or shorter than the fourth peak wavelength. The filter is disposed over the light emitting device in the path of at least a portion of the first, second, and third light. | 03-04-2010 |
20100041170 | Package-Integrated Thin Film LED - LED epitaxial layers (n-type, p-type, and active layers) are grown on a substrate. For each die, the n and p layers are electrically bonded to a package substrate that extends beyond the boundaries of the LED die such that the LED layers are between the package substrate and the growth substrate. The package substrate provides electrical contacts and conductors leading to solderable package connections. The growth substrate is then removed. Because the delicate LED layers were bonded to the package substrate while attached to the growth substrate, no intermediate support substrate for the LED layers is needed. The relatively thick LED epitaxial layer that was adjacent the removed growth substrate is then thinned and its top surface processed to incorporate light extraction features. There is very little absorption of light by the thinned epitaxial layer, there is high thermal conductivity to the package because the LED layers are directly bonded to the package substrate without any support substrate therebetween, and there is little electrical resistance between the package and the LED layers so efficiency (light output vs. power input) is high. The light extraction features of the LED layer further improves efficiency. | 02-18-2010 |
20100029023 | CONTROLLING EDGE EMISSION IN PACKAGE-FREE LED DIE - Light emitting diode (LED) structures are fabricated in wafer scale by mounting singulated LED dies on a carrier wafer or a stretch film, separating the LED dies to create spaces between the LED dies, applying a reflective coating over the LED dies and in the spaces between the LED dies, and separating or breaking the reflective coating in the spaces between the LED dies such that some reflective coating remains on the lateral sides of the LED die. Portions of the reflective coating on the lateral sides of the LED dies may help to control edge emission. | 02-04-2010 |
20100006864 | IMPLANTED CONNECTORS IN LED SUBMOUNT FOR PEC ETCHING BIAS - A sapphire growth substrate wafer has epitaxially grown over it N-type layers, an active layer, and P-type layers to form GaN LEDs. Each LED is a flip-chip with its cathode contact and anode contact formed on the same side. The wafer is then diced to separate out the LEDs. A P-type silicon submount wafer has N-type doped interconnect regions for interconnecting all the cathode contacts together after the LEDs are mounted on the submount wafer. The sapphire substrate is then removed by a laser lift-off process. A bias voltage is then applied to the cathode contacts via the interconnect regions to bias the N-type layers for a photo-electrochemical etching process that roughens the exposed layer for increased light extraction. The submount wafer is then diced, cutting through the doped interconnect regions. | 01-14-2010 |
20090261361 | III-NITRIDE LIGHT EMITTING DEVICE WITH DOUBLE HETEROSTRUCTURE LIGHT EMMITTING REGION - A III-nitride light emitting layer is disposed between an n-type region and a p-type region in a double heterostructure. At least a portion of the III-nitride light emitting layer has a graded composition. | 10-22-2009 |
20090250713 | Reflective Contact for a Semiconductor Light Emitting Device - A light emitting device includes a semiconductor structure comprising a light emitting layer disposed between an n-type region and a p-type region. A contact is formed on the semiconductor structure, the contact comprising a reflective metal in direct contact with the semiconductor structure and an additional metal or semi-metal disposed within the reflective metal. In some embodiments, the additional metal or semi-metal is a material with higher electronegativity than the reflective metal. The presence of the high electronegativity material in the contact may increase the overall electronegativity of the contact, which may reduce the forward voltage of the device. In some embodiments, an oxygen-gathering material is included in the contact. | 10-08-2009 |
20090230409 | UNDERFILL PROCESS FOR FLIP-CHIP LEDS - An underfill technique for LEDs uses compression molding to simultaneously encapsulate an array of flip-chip LED dies mounted on a submount wafer. The molding process causes liquid underfill material (or a softened underfill material) to fill the gap between the LED dies and the submount wafer. The underfill material is then hardened, such as by curing. The cured underfill material over the top and sides of the LED dies is removed using microbead blasting. The exposed growth substrate is then removed from all the LED dies by laser lift-off, and the underfill supports the brittle epitaxial layers of each LED die during the lift-off process. The submount wafer is then singulated. This wafer-level processing of many LEDs simultaneously greatly reduces fabrication time, and a wide variety of materials may be used for the underfill since a wide range of viscosities is tolerable. | 09-17-2009 |
20090191658 | SEMICONDUCTOR LIGHT EMITTING DEVICE WITH LATERAL CURRENT INJECTION IN THE LIGHT EMITTING REGION - A semiconductor light emitting device includes an active region, an n-type region, and a p-type region comprising a portion that extends into the active region. The active region may include multiple quantum wells separated by barrier layers, and the p-type extension penetrates at least one of the quantum well layers. The extensions of the p-type region into the active region may provide uniform filling of carriers in the individual quantum wells of the active region by providing direct current paths into individual quantum wells. Such uniform filling may improve the operating efficiency at high current density by reducing the carrier density in the quantum wells closest to the bulk p-type region, thereby reducing the number of carriers lost to nonradiative recombination. | 07-30-2009 |
20090173956 | CONTACT FOR A SEMICONDUCTOR LIGHT EMITTING DEVICE - An AlGaInP light emitting device is formed as a thin, flip chip device. The device includes a semiconductor structure comprising an AlGaInP light emitting layer disposed between an n-type region and a p-type region. N- and p-contacts electrically connected to the n- and p-type regions are both formed on the same side of the semiconductor structure. The semiconductor structure is connected to the mount via the contacts. The growth substrate is removed from the semiconductor structure and the thick transparent substrate is omitted, such that the total thickness of semiconductor layers in the device is less than 15 μm in some embodiments, less than 10 μm in some embodiments. The top side of the semiconductor structure may be textured. | 07-09-2009 |
20090170226 | Package for a Semiconductor Light Emitting Device - A semiconductor light emitting device package includes a substrate with a core and a copper layer overlying the core. The light emitting device is connected to the substrate directly or indirectly through a wiring substrate. The core of the substrate may be, for example, ceramic, Al | 07-02-2009 |
20090159908 | SEMICONDUCTOR LIGHT EMITTING DEVICE WITH LIGHT EXTRACTION STRUCTURES - Structures are incorporated into a semiconductor light emitting device which may increase the extraction of light emitted at glancing incidence angles. In some embodiments, the device includes a low index material that directs light away from the metal contacts by total internal reflection. In some embodiments, the device includes extraction features such as cavities in the semiconductor structure which may extract glancing angle light directly, or direct the glancing angle light into smaller incidence angles which are more easily extracted from the device. | 06-25-2009 |
20090155943 | Luminescent Ceramic Element For A Light Emitting Device - A semiconductor structure including a light emitting layer disposed between an n-type region and a p-type region is attached to a compound substrate including a host which provides mechanical support to the device and a ceramic layer including a luminescent material. In some embodiments the compound substrate includes a crystalline seed layer on which the semiconductor structure is grown. The ceramic layer is disposed between the seed layer and the host. In some embodiments, the compound substrate is attached to the semiconductor structure after growth of the structure on a conventional growth substrate. In some embodiments, the compound substrate is spaced apart from the semiconductor structure and does not provide mechanical support to the structure. In some embodiments, the ceramic layer has a thickness less than 500 μm. | 06-18-2009 |
20090154166 | Light Emitting Diode for Mounting to a Heat Sink - A light emitting diode (LED) apparatus for mounting to a heat sink having a front surface with an opening therein is disclosed. The apparatus includes a sub-mount, at least one LED die mounted on the sub-mount, and a thermally conductive slug having first and second areas. The first area is thermally coupled to the sub-mount and the second area has a post protruding outwardly therefrom. The post is operably configured to be received in the opening in the heat sink and to secure the LED apparatus to the heat sink such that the second area is thermally coupled to the front surface of the heat sink. Other embodiments for mounting an LED apparatus utilizing adhesive thermally conductive material, spring clips, insertion snaps, or welding are also disclosed. | 06-18-2009 |
20090154137 | Illumination Device Including Collimating Optics - A structure for providing a collimated light beam includes a light source configured to emit light having a first peak wavelength combined with a group of structures configured to direct at least a portion of light exiting the light source in a direction substantially perpendicular to a top surface of the light source and reflect another portion. In some embodiments, a wavelength converting element is positioned in a path of light emitted from the light source, the wavelength converting element configured to absorb at least a portion of the light having a first peak wavelength and emit light having a second peak wavelength. The group of structures may be formed over the wavelength converting element, such that the wavelength converting element is disposed between the group of structures and the light source. | 06-18-2009 |
20090152584 | LIGHT EMITTING DEVICE WITH BONDED INTERFACE - In some embodiments of the invention, a transparent substrate AlInGaP device includes an etch stop layer that may be less absorbing than a conventional etch stop layer. In some embodiments of the invention, a transparent substrate AlInGaP device includes a bonded interface that may be configured to give a lower forward voltage than a conventional bonded interface. Reducing the absorption and/or the forward voltage in a device may improve the efficiency of the device. | 06-18-2009 |
20090141212 | Illumination Module For Sectional Illumination - A backlight for a display includes a plurality of illumination modules, each illumination module including a light source and a reflective member. A portion of the reflective member is disposed over the light source. A liquid crystal display panel is disposed over the plurality of illumination modules. The reflective member is configured such that a majority of light from the light source is directed parallel to the liquid crystal display panel, to provide uniform illumination of the liquid crystal display panel. In some embodiments, the light source is at least one semiconductor light emitting diode. | 06-04-2009 |
20090140274 | III-Nitride Light Emitting Device Including Porous Semiconductor Layer - A semiconductor structure comprising a III-nitride light emitting layer disposed between an n-type region and a p-type region is grown over a porous III-nitride region. A III-nitride layer comprising InN is disposed between the light emitting layer and the porous III-nitride region. Since the III-nitride layer comprising InN is grown on the porous region, the III-nitride layer comprising InN may be at least partially relaxed, i.e. the III-nitride layer comprising InN may have an in-plane lattice constant larger than an in-plane lattice constant of a conventional GaN layer grown on sapphire. | 06-04-2009 |
20090123764 | Silicone Resin for Protecting a Light Transmitting Surface of an Optoelectronic Device - A silicone resin composition and process for coating a light transmitting surface of an optoelectronic device is disclosed. The process involves applying a silicone resin to the light transmitting surface, and causing the silicone resin to cure to form a light transmitting protective coating on the light transmitting surface, the silicone resin having a sufficiently low proportion of organosiloxanes having molecular weights of up to about 1000, such that the protective coating includes less than about 10% of the organosiloxanes having molecular weights of up to about 1000. | 05-14-2009 |
20090101929 | ROBUST LED STRUCTURE FOR SUBSTRATE LIFT-OFF - An etching step is performed on an LED/substrate wafer to etch through the LED epitaxial layers entirely around each LED on the substrate wafer to form a gap between each LED on the wafer. The substrate is not etched. When the LEDs/substrates are singulated, edges of each substrate extend beyond edges of the LED die. The LEDs are flip-chips and are mounted on a submount with the LED die between the submount and the substrate. An insulating underfill material is injected under the LED die and also covers the sides of the LED die and “enlarged” substrate. The substrate is then removed by laser lift-off. The raised walls of the underfill that were along the edges of the enlarged substrate are laterally spaced from the edges of the LED die so that a phosphor plate can be easily positioned on top to the LED die with a relaxed positioning tolerance. | 04-23-2009 |
20090086508 | Thin Backlight Using Low Profile Side Emitting LEDs - Backlights containing low profile, side-emitting LEDs are described that have improved brightness uniformity. In one embodiment, the backlight comprises a solid transparent lightguide with a plurality of openings in a bottom surface of the lightguide, each opening containing a side-emitting LED. Prisms or other optical features are formed in the top wall of each opening to reflect light in the lightguide towards a light output surface of the lightguide so that the side-emitting LEDs do not appear as dark spots at the output of the backlight. To avoid any direct emission from the sides of the LED toward the output surface of the lightguide appearing as bright areas, optical features are formed at the edges of the opening or in the output surface of the lightguide so that direct emission light is not output from the lightguide. Substantially identical cells may be formed in the lightguide using cellular walls around one or more LEDs. | 04-02-2009 |
20090072263 | Color Control By Alteration of Wavelength Converting Element - A light emitting device is produced by depositing a layer of wavelength converting material over the light emitting device, testing the device to determine the wavelength spectrum produced and correcting the wavelength converting member to produce the desired wavelength spectrum. The wavelength converting member may be corrected by reducing or increasing the amount of wavelength converting material. In one embodiment, the amount of wavelength converting material in the wavelength converting member is reduced, e.g., through laser ablation or etching, to produce the desired wavelength spectrum. | 03-19-2009 |
20090067170 | Compact Optical System and Lenses for Producing Uniform Collimated Light - An optical system includes a cylindrical side emitter lens, a reflector and a cylindrical Fresnel lens to produce a substantially uniformly illuminated exit plane with well collimated light in the forward direction. The cylindrical side emitter lens redirects light from a light source, such as a number of light emitting diodes placed in a straight line, into side emitted light along an optical axis that is parallel with the exit plane. The reflector may be a stepped multi-focal length reflector that includes multiple reflector surfaces with different focal lengths based on the surfaces distance to the light source and height to redirect light from the cylindrical side emitter lens to illuminate the exit plane and collimate the light along one axis in the forward direction. The cylindrical Fresnel lens is used to collimate the light along an orthogonal axis in the forward direction. | 03-12-2009 |
20090057699 | LED with Particles in Encapsulant for Increased Light Extraction and Non-Yellow Off-State Color - In one embodiment, sub-micron size granules of TiO | 03-05-2009 |
20090052158 | Light Source Including Reflective Wavelength-Converting Layer - A light source configured to emit first light is combined with a wavelength-converting layer. The wavelength-converting layer is disposed in a path of first light, is spaced apart from the light source, and includes at least one wavelength-converting material such as a phosphor configured to absorb first light and emit second light. The wavelength-converting layer is disposed between a reflective layer and the light source. In some embodiments, the wavelength-converting layer is a thick layer. | 02-26-2009 |
20090051831 | Light Source For A Projector - A projector includes a plurality of illumination modules. Each illumination module includes a light source, such as a semiconductor light emitting diode, and an optical element configured to receive light from the light source and collimate the light into a beam. Light from the illumination modules is provided to a liquid crystal display panel, then a projection lens. In some embodiments, secondary optics, such as an array of Fresnel lenses or a reflective polarizer, are disposed between the illumination modules and the liquid crystal display panel. In some embodiments, the liquid crystal display panel is a low temperature polysilicon liquid crystal display. | 02-26-2009 |
20090050921 | Light Emitting Diode Array - A one-dimensional array of light emitting diodes (LEDs) is configured to place the LEDs in close proximity to each other, e.g., 150 μm or less and to place at least one side of the LEDs in close proximity to the edge of the substrate, e.g., 150 μm or less. With the LEDs close to the edge of the substrate, multiple one-dimensional arrays may be joined together, side by side, to form a two-dimensional array with the LEDs from adjacent one-dimensional arrays positioned close together. By minimizing the gaps between the LEDs on the same one-dimensional arrays and adjacent one-dimensional arrays, the luminance of the device is improved making the device suitable for high radiance applications. Moreover, using a number of one-dimensional arrays to form a larger two-dimensional array increases yield relative to conventional monolithic two-dimensional arrays. | 02-26-2009 |
20090046479 | Thin Backlight Using Low Profile Side Emitting LED - Low profile, side-emitting LEDs are described. The LEDs are used in very thin backlights for backlighting an LCD. In one embodiment, the backlight comprises a solid transparent waveguide with at least one opening in the waveguide containing an LED proximate to one edge. To smooth out a clover-shaped or batwing brightness profile inherently generated by a rectangular side-emitting LED within a smooth-sided rectangular opening in the waveguide, depending on the orientation of the LED, the sidewalls of the opening are made to have varying angles along the length of each sidewall to vary the refraction angle of light along the sidewall. Additionally, if a plurality of LEDs are used in the backlight, the orientations of the openings alternate to create a more uniform brightness profile in the waveguide. | 02-19-2009 |
20090045427 | Photonic Crystal Light Emitting Device - A photonic crystal structure is formed in an n-type region of a III-nitride semiconductor structure including an active region sandwiched between an n-type region and a p-type region. A reflector is formed on a surface of the p-type region opposite the active region. In some embodiments, the growth substrate on which the n-type region, active region, and p-type region are grown is removed, in order to facilitate forming the photonic crystal in an n-type region of the device, and to facilitate forming the reflector on a surface of the p-type region underlying the photonic crystal. The photonic crystal and reflector form a resonant cavity, which may allow control of light emitted by the active region. | 02-19-2009 |
20090045420 | Backlight Including Side-Emitting Semiconductor Light Emitting Devices - Individual side-emitting LEDs are separately positioned in a waveguide, or mounted together on a flexible mount then positioned together in a waveguide. As a result, the gap between each LED and the waveguide can be small, which may improve coupling of light from the LED into the waveguide. Since the LEDs are separately connected to the waveguide, or mounted on a flexible mount, stress to individual LEDs resulting from changes in the shape of the waveguide is reduced. | 02-19-2009 |
20090045416 | Optical Element Coupled to Low Profile Side Emitting LED - A low profile, side-emitting LED with one or more optical elements, such as a reflector or lens, optically coupled to each light emitting sidewall is described. In one embodiment, a reflector is used to redirect the light emitted from each sidewall to a forward direction, e.g., in a flash configuration. In another embodiment, a lens is used to collimate the side emitted light in the horizontal plane, e.g., for backlighting. Each entrance surface of the lens is positioned so that the bottom edge is at or below the bottom of the light emitting sidewall so that the base of the lens does not block light that is emitted by the LED. | 02-19-2009 |
20090032828 | III-Nitride Device Grown on Edge-Dislocation Template - A semiconductor light emitting device includes a wurtzite III-nitride semiconductor structure including a light emitting layer disposed between an n-type region and a p-type region. A template layer and a dislocation bending layer are grown before the light emitting layer. The template layer is grown such that at least 70% of the dislocations in the template layer are edge dislocations. At least some of the edge dislocations in the template layer continue into the dislocation bending layer. The dislocation bending layer is grown to have a different magnitude of strain than the template layer. The change in strain at the interface between the template layer and the dislocation bending layer causes at least some of the edge dislocations in the template layer to bend to a different orientation in the dislocation bending layer. Semiconductor material grown above the bent edge dislocations may exhibit reduced strain. | 02-05-2009 |
20090032827 | Concave Wide Emitting Lens for LED Useful for Backlighting - Lenses for LEDs are described that efficiently create a substantially uniform light emission across a surface of a backlight box. The backlight may illuminate an LCD. A wide-emitting lens refracts light emitted by an LED die to cause a peak intensity to occur within 35-65 degrees off the die's center axis, normal to the die's top surface, and an intensity along the center axis to be between 40% and 90% of the peak intensity. The lens is concave over the die and has smooth edges that transition into the lens sidewalls. The direct emissions of the lenses from a plurality of LEDs arranged on a base surface in a backlight box combine together to uniformly illuminate a light output surface of the backlight box. | 02-05-2009 |
20090017566 | Substrate Removal During LED Formation - A light emitting diode (LED) is fabricated using an underfill layer that is deposited on either the LED or the submount prior to mounting the LED to a submount. The deposition of the underfill layer prior to mounting the LED to the submount provides for a more uniform and void free support, and increases underfill material options to permit improved thermal characteristics. The underfill layer may be used as support for the thin and brittle LED layers during the removal of the growth substrate prior to mounting the LED to the submount. Additionally, the underfill layer may be patterned to and/or polished back so that only the contact areas of the LED and/or submount are exposed. The patterns in the underfill may also be used as a guide to assist in the singulating of the devices. | 01-15-2009 |
20080315214 | Solderless Integrated Package Connector and Heat Sink for LED - Standard solderless connectors extend from a molded package body supporting at least one high power LED. The package includes a relatively large metal slug extending completely through the package. The LED is mounted over the top surface of the metal slug with an electrically insulating ceramic submount in-between the LED and metal slug. Electrodes on the submount are connected to the package connectors. Solderless clamping means, such as screw openings, are provided on the package for firmly clamping the package on a thermally conductive mounting board. The slug in the package thermally contacts the board to sink heat away from the LED. Fiducial structures (e,g., holes) in the package precisely position the package on corresponding fiducial structures on the board. Other packages are described that do not use a molded body. | 12-25-2008 |
20080308824 | Thin Flash or Video Recording Light Using Low Profile Side Emitting LED - Very thin flash modules for cameras are described that do not appear as a point source of light to the illuminated subject. Therefore, the flash is less objectionable to the subject. In one embodiment, the light emitting surface area is about 5 mm×10 mm. Low profile, side-emitting LEDs optically coupled to solid light guides enable the flash module to be thinner than 2 mm. The flash module may also be continuously energized for video recording. The module is particularly useful for cell phone cameras and other thin cameras. | 12-18-2008 |
20080304250 | Thin Luminaire for General Lighting Applications - High power white light LEDs are distributed within a thin reflective cavity. The cavity depth may be less than 3 cm and, in one embodiment, is about 1 cm. A light output surface of the cavity is a flat reflector with many small openings. A small plastic lens is positioned over each opening for causing the light emitted from each opening to form a cone of light between approximately 50-75 degrees. Alternatively, each hole may be shaped to be a truncated cone to control the dispersion. The light emitted by the LEDs is mixed in the cavity by reflecting off all six reflective walls of the cavity. The light will ultimately escape through the many holes, forming a relatively uniform pattern of light on a surface to be illuminated by the luminaire. | 12-11-2008 |
20080303039 | Mount for a Semiconductor Light Emitting Device - A mount for a semiconductor device includes a carrier, at least two metal leads disposed on a bottom surface of the carrier, and a cavity extending through a thickness of the carrier to expose a portion of the top surfaces of the metal leads. A semiconductor light emitting device is positioned in the cavity and is electrically and physically connected to the metal leads. The carrier may be, for example, silicon, and the leads may be multilayer structures, for example a thin gold layer connected to a thick copper layer. | 12-11-2008 |
20080290362 | Illumination Device with a Wavelength Converting Element Held by a Support Structure Having an Aperture - An illumination device includes a light source, such as one or more light emitting diodes and a wavelength converting element that is mounted on an opaque support structure. The support structure includes an aperture with which the wavelength converting element is aligned so that the converted light is emitted through the aperture. The wavelength converting element may be a rigid structure, such as a luminescent ceramic and the aperture may be a hole through the support structure. The support structure may hold the wavelength converting element so that it is physically separated from the light source, or alternatively, the support structure may place the wavelength converting element in physical contact with the light source. | 11-27-2008 |
20080266900 | Backlight Using LED Parallel to Light Guide Surface - Various embodiments of corner-coupled backlights are described, where one or more white light LEDs are optically coupled to a truncated corner edge of a solid rectangular light guide backlight. The one or more LEDs are mounted in a small reflective cavity, whose output opening is coupled to the truncated corner of the light guide. The reflective cavity provides a more uniform light distribution at a wide variety of angles to the face of the truncated corner to better distribute light throughout the entire light guide volume. To enable a thinner light guide, the LED die is positioned in the reflective cavity so that the major light emitting surface of the LED is parallel to the top surface of the light guide. The reflective cavity reflects the upward LED light toward the edge of the light guide. | 10-30-2008 |
20080265263 | Polarized Semiconductor Light Emitting Device - A light emitting device includes a light emitting diode (LED), a concentrator element, such as a compound parabolic concentrator, and a wavelength converting material, such as a phosphor. The concentrator element receives light from the LED and emits the light from an exit surface, which is smaller than the entrance surface. The wavelength converting material is, e.g., disposed over the exit surface. The radiance of the light emitting diode is preserved or increased despite the isotropic re-emitted light by the wavelength converting material. In one embodiment, the polarized light from a polarized LED is provided to a polarized optical system, such as a microdisplay. In another embodiment, the orthogonally polarized light from two polarized LEDs is combined, e.g., via a polarizing beamsplitter, and is provided to non-polarized optical system, such as a microdisplay. If desired, a concentrator element may be disposed between the beamsplitter and the microdisplay. | 10-30-2008 |
20080259980 | Semiconductor Light Emitting Device Including Oxide Layer - A device includes a semiconductor structure comprising a III-nitride light emitting layer disposed between an n-type region and a p-type region. The semiconductor structure is grown over an oxide layer disposed between first and second III-nitride layers. The oxide layer may at least partially relieve the strain in the light emitting layer by increasing the in-plane lattice constant of the template on which the light emitting layer is grown. The oxide layer may be formed by growing an AlInN layer in the device, etching a trench to expose the AlInN layer, then oxidizing the AlInN layer. | 10-23-2008 |
20080237619 | LED with Porous Diffusing Reflector - In one embodiment, an AlInGaP LED includes a bottom n-type layer, an active layer, a top p-type layer, and a thick n-type GaP layer over the top p-type layer. The thick n-type GaP layer is then subjected to an electrochemical etch process that causes the n-type GaP layer to become porous and light-diffusing. Electrical contact is made to the p-GaP layer under the porous n-GaP layer by providing metal-filled vias through the porous layer, or electrical contact is made through non-porous regions of the GaP layer between porous regions. The LED chip may be mounted on a submount with the porous n-GaP layer facing the submount surface. The pores and metal layer reflect and diffuse the light, which greatly increases the light output of the LED. Other embodiments of the LED structure are described. | 10-02-2008 |
20080212320 | Producing Distinguishable Light in the Presence of Ambient Light - A process and apparatus for producing distinguishable light, in the presence of ambient light is disclosed. The process involves admitting light in a first wavelength band through a first light admission port into a first optical cavity at least partially defined by a first reflector operably configured to reflect light out of the first optical cavity. The process also involves filtering ambient light reflected into the first optical cavity and entering and exiting a first space defined about the first light admission port such that ambient light outside the first wavelength band is attenuated on entry and exit from the first space. | 09-04-2008 |