Photonstar Led Limited

Synoptics Limited

Lumileds Holding B.v.

James Stuart McKenzie

Majd Zoorob

Thomas David Matthew Lee

Madj Zoorob

A tunable color LED module comprises at least two sub-modules, each comprising an LED, a wavelength converting element (WCE) and a reflector cup. The total light emitted by the module comprises light generated from each LED and WCE and the module is configured to emit a total light having a predefined color chromaticity when activation properties of the LEDs are managed appropriately. The total light may have a broad white emission spectrum. The module combines the benefits of a low cost with uniform chromaticity properties in the far field, and offers long and controlled lifetime at the same time as flexibility and intelligence of tunable color chromaticity, Color Rendering Index (CRI) and intensity, either at manufacture or in an end user lighting application. A controlled LED module system comprises a control system for the managing activation properties of the LEDs in the sub-modules. Also described is a method of manufacture.

Vertical light emitting diodes

Tunable colour LED module

A novel submount for the efficient dissipation of heat away from a semiconductor light emitting device is described, which also maintains efficient electrical conductivity to the n and p contacts of the device by separating the thermal and electrical conductivity paths. The submount comprises at least the following constituent layers: a substrate () with thermally conductive properties; a deposited layer () having electrically insulating and thermally conducting properties disposed on at least a region of the substrate having a thickness of between 50 nm and 50 microns; a patterned electrically conductive circuit layer () disposed on at least a region of the deposited layer; and, a passivation layer at least partially overcoating a top surface of the submount. Also described is a light emitting module employing the substrate and a method of manufacture of the submount.

High thermal performance packaging for optoelectronics devices

A light emitting device having a plurality of light extracting elements defined on an upper surface of a semiconductor layer of the device, wherein the light extracting elements are adapted to couple light out of the device and to modify the far field emission profile of the device. Each element comprises an elongate region having a length at least twice its width and also greater than the effective dominant wavelength of light generated in the device. The elongate region extends orthogonal to the upper surface but not into the light emitting region of the device and may be oriented at an angle of less than 45&#xb0; relative to one of a pair of basis axis defining a plane parallel to the semiconductor layer. Each elongate region is spatially separated from neighboring elongate regions such that it perturbs light generated in the light emitting region independently of the neighboring regions.

LED with enhanced light extraction

A light emitting device (LED) employs one or more conductive multilayer reflector (CMR) structures. Each CMR is located between the light emitting region and a metal electrical contact region, thereby acting as low-loss, high-reflectivity region that masks the lossy metal contact regions away from the trapped waveguide modes. Improved optical light extraction via an upper surface is thereby achieved and a vertical conduction path is provided for current spreading in the device. In an example vertical, flip-chip type device, a CMR is employed between the metal bottom contact and the p-GaN flip chip layer. A complete light emitting module comprises the LED and encapsulant layers with a phosphor. Also provided is a method of manufacture of the LED and the module.

A tunable color LED module comprises at least two sub-modules, each comprising an LED (), a wavelength converting element (WCE) () and a reflector cup. The total light emitted by the module comprises light generated from each LED and WCE and the module is configured to emit a total light having a predefined color chromaticity when activation properties of the LEDs are managed appropriately. The total light may have a broad white emission spectrum (). The module combines the benefits of a low cost with uniform chromaticity properties in the far field, and offers long and controlled lifetime at the same time as flexibility and intelligence of tunable color chromaticity, Color Rendering Index (CRI) and intensity, either at manufacture or in an end user lighting application. A controlled LED module system comprises a control system for the managing activation properties of the LEDs in the sub-modules. Also described is a method of manufacture.

A light emitting module with improved optical functionality and reduced thermal resistance is described, which comprises a light emitting device (LED), a wavelength converting (WC) element and an inorganic optically-transmissive thermally-conductive (OTTC) element. The WC element is capable of absorbing light generated from the LED at a specific wavelength and re-emitting light having a different wavelength. The re-emitted light and any unabsorbed light exits through at least one surface of the module. The OTTC is in physical contact with the WC element and at least partially located in the optical path of the light. The OTTC comprises one or more layers of inorganic material having a thermal conductivity greater than that of the WC element. As such, a compact unitary integrated module is provided with excellent thermal characteristics, which may be further enhanced when the OTTC provides a thermal barrier for vertical heat propagation through the module but not lateral propagation.

Light emitting module with optically-transparent thermally-conductive element

A light emitting module comprises a light emitting device (LED) mounted on a high thermal dissipation sub-mount, which performs the traditionally function of heat spread and the first part of the heat sinking. The sub-mount is a grown metal that is formed by an electroplating, electroforming, electrodeposition or electroless plating process, thereby minimizing thermal resistance at this stage. An electrically insulating and thermally conducting layer is at least partially disposed across the interface between the grown semiconductor layers of the light emitting device and the formed metal layers of the sub-mount to further improve the electrical isolation of the light emitting device from the grown sub-mount. The top surface of the LED is protected from electroplating or electroforming by a wax or polymer or other removable material on a temporary substrate, mold or mandrel, which can be removed after plating, thereby releasing the LED module for subsequent processing.

Ultra high thermal performance packaging for optoelectronics devices

A light emitting device is provided having high luminous output while maintaining high wall plug efficiency, wherein the high thermal and electrical conductivity paths of the device are separated during the semiconductor wafer and die level manufacturing step. The device includes an electrical conducting mirror layer, which reflects at least 60% of generated light incident on it, and an isolation layer having electrical insulating properties and thermal conducting properties. A first electrode, which is not in contact with the main semiconductor layers of the device, is located on the mirror layer. A light emitting module, system and projection system incorporating the light emitting device are also described, as is a method of manufacture of the device.

Electrically isolated vertical light emitting diode structure

A light emitting device comprises a novel low-loss array of conductive vias embedded in a dielectric multilayer stack, to act as an electrically-conductive, low-loss, high-reflectivity reflector layer (CVMR). In one example the CVMR stack is employed between a reflective metal bottom contact and a p-GaN semiconductor flip chip layer. The CVMR stack comprises at least (3) layers with at least (2) differing dielectric constants. The conductive vias are arranged such that localized and propagating surface plasmons associated with the structure reside within the electromagnetic stopband of the CVMR stack, which in turn inhibits trapped LED modes coupling into these plasmonic modes, thereby increasing the overall reflectivity of the CVM R. This technique improves optical light extraction and provides a vertical conduction path for optimal current spreading in a semiconductor light emitting device. A light emitting module and method of manufacture are also described.

Growing community of inventors

Falmouth, United Kingdom

James Stuart McKenzie