Abstract: A light emitting device is described. The light emitting device includes a substrate and a semiconductor structure. The semiconductor structure includes a light emitting layer disposed between an n-type region and a p-type region and has a first surface adjacent the substrate and a second surface opposite the first surface. The first surface of the semiconductor structure multiple cavities formed therein, which extend into at least one of the n-type region and the p-type region. The cavities are spaced apart and lined by a dielectric layer. At least a portion of the second surface is roughened to form multiple features spaced apart at a distance smaller than a distance between each of the cavities formed in the first surface to enhance extraction of light emitted from the light emitting layer. At least one contact is disposed between the first surface of the semiconductor structure and the substrate.

Abstract: A process for preparing a semiconductor structure for mounting to a carrier is disclosed. The process involves causing a support material to substantially fill a void defined by surfaces formed in the semiconductor structure and causing the support material to solidify sufficiently to support the semiconductor structure when mounted to the carrier.

Abstract: In one embodiment, the transparent growth substrate of an LED die is formed to have light scattering areas, such as voids formed by a laser. In another embodiment, the growth substrate is removed and replaced by another substrate that is formed with light scattering areas. In one embodiment, the light scattering areas are formed over the light absorbing areas of the LED die, to reduce the amount of incident light on those absorbing areas, and over the sides of the substrate to reduce light guiding. The replacement substrate may be formed to include reflective particles in selected areas. A 3D structure may be formed by stacking substrate layers containing the reflective areas. The substrate may be a transparent substrate or a phosphor tile that is affixed to the top of the LED.

Abstract: Embodiments include systems, methods, and apparatuses for providing a dimming function in a single stage AC input light emitting diode (LED) driver with a controller that contains an on-chip error amplifier and an on-chip fixed reference voltage source coupled to a first input of the error amplifier. The controller controls a duty cycle of a switching transistor to cause a feedback voltage, applied to a first package input terminal, to match the reference voltage. To achieve a dimming function, a voltage across a current sense resistor in series with the LEDs is applied to a first input of a high gain differential amplifier, and a variable dimming control voltage is applied to a second input of the differential amplifier. The output of the differential amplifier is coupled to the first package input terminal. The differential amplifier input signals will be matched at the target LED current level.

Abstract: A light-emitting device is disclosed that includes a semiconductor structure having an active region disposed between an n-type layer and a p-type layer; a wavelength converter formed above the semiconductor structure; an insulating side coating formed around the semiconductor structure; and a reflective side coating formed around the wavelength converter above the insulating side coating, the reflective side coating having a top surface that is flush with a top surface of the wavelength converter.

Abstract: In embodiments of the invention, a light emitting device includes a semiconductor structure including a light emitting layer disposed between an n-type region and a p-type region. A first wavelength converting layer is disposed in a path of light emitted by the light emitting layer. The first wavelength converting layer may be a wavelength converting ceramic. A second wavelength converting layer is fused to the first wavelength converting layer. The second wavelength converting layer may be a wavelength converting material disposed in glass.

Abstract: A multi-layer metal core printed circuit board (MCPCB) has mounted on it at least one or more heat-generating LEDs and one or more devices configured to provide current to the one or more LEDs. The one or more devices may include a device that carries a steep slope voltage waveform. Since there is typically a very thin dielectric between the patterned copper layer and the metal substrate, the steep slope voltage waveform may produce a current in the metal substrate due to AC coupling via parasitic capacitance. This AC-coupled current may produce electromagnetic interference (EMI). To reduce the EMI, a local shielding area may be formed between the metal substrate and the device carrying the steep slope voltage waveform. The local shielding area may be conductive and may be electrically connected, to a DC voltage node adjacent to the one or more devices.

Abstract: In one embodiment, a solid cylindrical tablet is pre-formed for a reflective cup containing an LED die, such as a blue LED die. The tablet comprises uniformly-mixed phosphor particles and transparent/translucent particles of a high TC material, such as quartz, in a hardened silicone binder, where the index of refraction of the high TC material is matched to that of the silicone to minimize internal reflection. Tablets can be made virtually identical in composition and size. The bulk of the tablet will be the high TC material. After the tablet is placed in the cup, the LED module is heated, preferably in a vacuum, to melt the silicone so that the mixture flows around the LED die and fills the voids to encapsulate the LED die. The silicone is then cooled to harden.

Abstract: 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.

Abstract: In one embodiment, the transparent growth substrate of an LED die is formed to have light scattering areas, such as voids formed by a laser. In another embodiment, the growth substrate is removed and replaced by another substrate that is formed with light scattering areas. In one embodiment, the light scattering areas are formed over the light absorbing areas of the LED die, to reduce the amount of incident light on those absorbing areas, and over the sides of the substrate to reduce light guiding. The replacement substrate may be formed to include reflective particles in selected areas. A 3D structure may be formed by stacking substrate layers containing the reflective areas. The substrate may be a transparent substrate or a phosphor tile that is affixed to the top of the LED.

Abstract: Described herein are methods for using remote plasma chemical vapor deposition (RP-CVD) and sputtering deposition to grow layers for light emitting devices. A method includes growing a light emitting device structure on a growth substrate, and growing a tunnel junction on the light emitting device structure using at least one of RP-CVD and sputtering deposition. The tunnel junction includes a p++ layer in direct contact with a p-type region, where the p++ layer is grown by using at least one of RP-CVD and sputtering deposition. Another method for growing a device includes growing a p-type region over a growth substrate using at least one of RP-CVD and sputtering deposition, and growing further layers over the p-type region. Another method for growing a device includes growing a light emitting region and an n-type region using at least one of RP-CVD and sputtering deposition over a p-type region.

Abstract: A method of separating a wafer including rows of light emitting devices is described. Dicing streets are provided on the wafer such that a respective one of the dicing streets is provided between each of the rows of light emitting devices on the wafer. The wafer is broken along a first one of the dicing streets to separate a first portion of the wafer from a remaining portion of the wafer. The first portion of the wafer includes more than one of the rows of light emitting devices. The first portion of the wafer is broken along a second one of the dicing streets to separate a second portion of the wafer from the first portion of the wafer.

Abstract: Methods and apparatus are described. An apparatus includes a hexagonal oxide substrate and a III-nitride semiconductor structure adjacent the hexagonal oxide substrate. The III-nitride semiconductor structure includes a light emitting layer between an n-type region and a p-type region. The hexagonal oxide substrate has an in-plane coefficient of thermal expansion (CTE) within 30% of a CTE of the III-nitride semiconductor structure.

Abstract: A control circuit for a light emitting diode (LED) lighting system for achieving a dim-to-warm effect is provided. The control circuit includes an LED controller, a clamp circuit coupled to a set of warm correlated-color-temperature (“CCT”) LEDs, a switch coupled to a set of cool LEDs, and a feedback circuit coupled to the clamp and the switch. The LED controller is configured to control the clamp circuit to clamp current through the set of warm LEDs based on the input current, and control the switch to switch on the set of cool LEDs responsive to the input current being greater than a first threshold level and to switch off the set of cool LEDs responsive to the input current being lower than the first threshold level. The feedback circuit is configured to divert current from the set of warm LEDs to the set of cool LEDs.

Abstract: A light emitting diode (“LED”) module is disclosed. The LED module includes a first LED tap and a second LED tap, the first tap being powered on for a longer amount of time than the second LED tap, based on an alternating current voltage. The LED module also includes a first LED package on which a first LED associated with the first LED tap and a second LED associated with the second LED tap are disposed. The LED module further includes a second LED package on which a third LED associated with the first LED tap and a fourth LED associated with the second LED tap are disposed.

Abstract: A flash system for an electronic device includes a ring-shaped light guide having a central opening. A camera lens is positioned in or behind the opening. A first light emitting diode (“LED”) is mounted on a printed circuit board (“PCB”), and the LED and PCB are encapsulated by a molded light guide of the flash system. An identical LED and PCB are encapsulated at an opposite end of the molded light guide (i.e., 180 degrees away). The back surfaces of each PCB diffusively reflects light from the LED on the other PCB. Light extraction features on the light guide surface uniformly leak out light from the LEDs. The light emission profile of the light guide has a peak axially aligned with the central opening of the light guide and rolls off to the edge of the camera's field of view.

Abstract: A hollow frame is configured to surround the periphery of a substantially self-supporting flip-chip light emitting device. The frame may be shaped to also contain a wavelength conversion element above the light emitting surface of the light emitting device. The lower surface of the light emitting device, which is exposed through the hollow frame, includes contact pads coupled to the light emitting element for surface mounting the light emitting module on a printed circuit board or other fixture. The flip-chip light emitting device may include a patterned sapphire substrate (PSS) upon which the light emitting element is grown, the patterned surface providing enhanced light extraction from the light emitting element, through the patterned sapphire substrate.

Abstract: 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.

Abstract: An LED die conformally coated with phosphor is mounted at the base of a shallow, square reflector cup. The cup has flat reflective walls that slope upward from its base to its rim at a shallow angle of approximately 33 degrees. A clear encapsulant completely fills the cup to form a smooth flat top surface. Any emissions from the LED die or phosphor at a low angle are totally internally reflected at the flat air-encapsulant interface toward the cup walls. This combined LED/phosphor light is then reflected upward by the walls and out of the package. Since a large percentage of the light emitted by the LED and phosphor is mixed by the TIR and the walls prior to exiting the package, the color and brightness of the reflected light is fairly uniform across the beam. The encapsulant is intentionally designed to enhance TIR to help mix the light.

Abstract: A semiconductor light emitting device comprising a light emitting layer disposed between an n-type region and a p-type region is combined with a ceramic layer which is disposed in a path of light emitted by the light emitting layer. The ceramic layer is composed of or includes a wavelength converting material such as a phosphor. Luminescent ceramic layers according to embodiments of the invention may be more robust and less sensitive to temperature than prior art phosphor layers. In addition, luminescent ceramics may exhibit less scattering and may therefore increase the conversion efficiency over prior art phosphor layers.