Patent application number | Description | Published |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
20110057205 | LED WITH PHOSPHOR TILE AND OVERMOLDED PHOSPHOR IN LENS - Overmolded lenses and certain fabrication techniques are described for LED structures. In one embodiment, thin YAG phosphor plates are formed and affixed over blue LEDs mounted on a submount wafer. A clear lens is then molded over each LED structure during a single molding process. The LEDs are then separated from the wafer. The molded lens may include red phosphor to generate a warmer white light. In another embodiment, the phosphor plates are first temporarily mounted on a backplate, and a lens containing a red phosphor is molded over the phosphor plates. The plates with overmolded lenses are removed from the backplate and affixed to the top of an energizing LED. A clear lens is then molded over each LED structure. The shape of the molded phosphor-loaded lenses may be designed to improve the color vs. angle uniformity. Multiple dies may be encapsulated by a single lens. In another embodiment, a prefabricated collimating lens is glued to the flat top of an overmolded lens. | 03-10-2011 |
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 |
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 |
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 |
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 |
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 |
20130133836 | LAMINATING APPARATUS - A laminating apparatus is provided which causes a resin film to completely conform to protruding and recessed portions of a substrate, and which makes the film thickness of the conforming resin film uniform on a stricter level. To this end, the laminating apparatus includes a laminating mechanism including: an enclosed space forming receiver capable of receiving a provisionally laminated body therein; and a pressure laminator for applying pressure to the provisionally laminated body in non-contacting relationship in an enclosed space formed by the enclosed space forming receiver to form an end laminated body from the provisionally laminated body. | 05-30-2013 |
20130221835 | LAMINATE SUPPORT FILM FOR FABRICATION OF LIGHT EMITTING DEVICES AND METHOD ITS FABRIACATION - Optical elements ( | 08-29-2013 |
20140193931 | METHOD OF BONDING A SUBSTRATE TO A SEMICONDUCTOR LIGHT EMITTING DEVICE - A method according to embodiments of the invention includes positioning a flexible film ( | 07-10-2014 |
20140284648 | 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. | 09-25-2014 |
20150027640 | LAMINATING APPARATUS - A laminating apparatus for a provisionally laminated body is provided and is configured to form an end laminated body including one of a first resin film and a second resin film conforming to protruding and recessed portions of a substrate. The laminating apparatus may include first and second laminating mechanisms. The first laminating mechanism may include a first enclosed space forming receiver, a depressurizer, a heater, and a first pressure laminator to form an intermediate laminated body from the provisionally laminated body. The second laminating mechanism may include a second enclosed space forming receiver, and a second pressure laminator to form the end laminated body from the intermediate laminated body. | 01-29-2015 |