Epistar Corporation

Epistar Co.

Jacob C Tarn

Jou Ming-Jiunn

Lee Biing-Jye

Biing-Jye Lee

Ming-Jiunn Jou

Liu Chia-Cheng

Hsing-Kuo Hsia

Ching-Hui Chen

Chuan-Ming Chang

Chih-Chia Lin

Chang Chuan-Ming

Chiung-Sheng Shyu

The present disclosure involves a method of packaging light-emitting diodes (LEDs). A carrier having a first side and a second opposite the first side is provided. The carrier includes a plurality of conductive interconnect elements. An integrated circuit (IC) die is bonded to the first side of the carrier. A packaging material having light-reflective properties is molded over the first and second sides of the carrier such that the IC die is sealed by the packaging material. A portion of the packaging material is molded into a reflective cap structure. A light-emitting diode (LED) is bonded to the second side of the carrier. Sidewalls of the reflective cap structure circumferentially surround the LED. The LED and the IC die are electrically coupled together through the conductive interconnect elements in the carrier. A lens is then formed over the LED.

LED with IC integrated lighting module

A nitride light emitting diode is fabricated on a transparent sapphire substrate. The LED is then mounted upside-down on a conductive silicon substrate with a bottom electrode to serve as the output terminal for the cathode of the LED. The LED die is partially etched to expose the anode of the LED, where a top electrode is formed. In comparison with conventional LED structure with both electrodes located on top of the die, moving one electrode to the bottom allows more light to be transmitted upward and reflects the light incident downward. For equal amount of light emission, the new structure occupies less area.

Inverted light emitting diode

A transparent conductive layer is deposited between the electrode and the semiconductor diode to spread the current evenly to the diode and to reduce the series resistance. Tin indium oxide can be used as the transparent conductive layer. The transparent conductive layer is particularly applicable to a blue light emitting diode, where InGaN is used as the light emitting layer.

Indium gallium nitride light emitting diode

A structure of a light emitting diode (LED) having high brightness is disclosed. This LED includes a substrate on a first electrode, a first cladding layer of a first conductivity type on the substrate, an active layer on the first cladding layer, a second cladding layer of a second conductivity type on the active layer, a window layer of the second conductivity type on the second cladding layer, wherein the electrical resistivity of the window layer is less than that of the second cladding layer, a contact layer of the second conductivity type on the window layer for providing ohmic contact, and a conductive transparent oxide layer on the contact layer, wherein the electrical resistivity of the conductive transparent oxide layer is less than that of the window layer and the contact layer.

High efficiency light emitting diode with distributed Bragg reflector

A high bandgap material is used as a cladding layer to confine the carrier overflow in a aluminum-gallium-indium-phosphide light emitting diode. The quantum efficiency is improved. The use of this high bandgap material as a window material also prevents current crowding. The efficiency can further be improved by using a Distributed Bragg Reflector in the structure to reflect light, and a buffer layer to reduce interface dislocation.

Light emitting diode with asymmetrical energy band structure

A structure of a light emitting diode (LED) having high brightness is disclosed. This LED includes a substrate formed on a first electrode, a first cladding layer of a first conductivity type formed on the substrate, an active layer formed on the first cladding layer, a second cladding layer of a second conductivity type formed on the active layer, a window layer of the second conductivity type formed on the second cladding layer, wherein the electrical resistivity of the window layer is less than the electrical resistivity of the second cladding layer, a contact layer of the second conductivity type formed on the window layer for providing ohmic contact, a conductive transparent oxide layer formed on the contact layer, and a current blocking region formed in the LED. The current blocking region is approximately aligned with a second electrode, and can be the contact layer having a hollow portion therein, an insulating region formed on the contact layer, an ion implanted region in the contact layer and the window layer, or a diffused region in the contact layer and the window layer.

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Hsinchu, Taiwan

Jacob C Tarn