Hitachi electric wire high power red chip LED 55 lumens

Hitachi Electric Corporation (Tokyo Stock Exchange: 5812) announced the development of high power LED red chip (1), the chip can provide maximum luminous flux of 55 lumens (2), (3). This flux is achieved by increasing the LED chip size and using a thin wire electrode structure.

LED is a semiconductor solid-state component that converts electrical energy directly into light. LED is widely used in various equipment, equipment and devices because of the ability to emit light of a specific color at a low operating voltage without a filter. The luminous efficiency, and a wide range of commercial blue and green LED manufacturing, the rapid expansion of the LED used in full-color display and lighting applications, including traffic lights, automobile tail lights and a large outdoor display board.

Hitachi electric wire manufacturing and supply of aluminum gallium arsenide (AlGaAs) epitaxial films and aluminum gallium indium phosphide (AlGaInP) epitaxial films, both compounds for semiconductor manufacturing Red LED. In order to meet the demand for higher luminous efficiency LED, the company also developed a high brightness red LED chip (hereinafter referred to as the "MR-LED chip"), the chip in the light-emitting layer to form a metal reflector (MR). This product is currently available for LED packaging manufacturers and other customers.

Through its LED business, Hitachi cable to realize that more and more people need more high lumen output LED chip. The company uses a fine electrode structure, and increase the size of the chip, in order to develop the supply of up to 55 lumens output high power red chip LED.

One way to increase the output per chip is to increase the size of the chip. However, the larger chip increases the difficulty of assigning a uniform current across the entire light-emitting layer. On the other hand, if a large electrode is placed on the upper layer of the chip to obtain a more uniform current distribution, the light from the light emitting layer is blocked, thereby reducing the light extraction efficiency.

In the development of new LED chip, in order to solve these problems, Hitachi does not use wire electrode more, but in the upper chip using two electrode attenuation to receive power, one connecting the two electrodes of the central electrode, and a plurality of extending to the central electrode wire electrode.

By using the thin wire electrode wire, Hitachi successfully in the entire surface of the chip to realize the current distribution, but does not block the light from the light emitting layer, resulting in a large LED chip 1 mm X1 mm size in volume flux of 55 lumens maximum equivalent to 21 MR-LED chips (0.33 mm x0.33 mm) with output. (4) because of its high output, the new LED chip is expected to be used not only in display applications, but also as a light source such as projectors.

Hitachi LED chip wire will continue to actively develop higher power, while expanding its high power LED chip camp products, including yellow and infrared LED chip.

(Note 1) LED represents Light Emitting Diode (light emitting diode).

(Note 2) lumen (LM) is a unit of light density, indicating that the human eye on the visible light.

(Note 3) optical output current of 500 mA

(Note 4) with our MR-LED chip (0.33 x with a current of 20 mA and a current output of 0.33 MA) for a comparison of 2.6 lumens