Reduce the cost of high-brightness LED wafer bonding and testing

Main purpose of high-brightness LED, including lights, lights and SI4835DY-T1 datasheet and backlit display. Although the high cost of high-brightness LED, but its superiority to LED application is acceptable. Fat also has a high brightness LED for general lighting potential. In order to reduce the cost of high-brightness LED to be used for bedroom, office and SI4835DY-T1 price and car parks, it is necessary to improve the manufacture of high brightness LED production efficiency to achieve lower cost of single-bit lumen purposes. This can replace the high-brightness LED production is still a variety of fluorescent and SI4835DY-T1 suppliers and incandescent lamps. High Brightness LEDs a significant advantage is that its life is measured in decades.

A variety of high-brightness LED emission of photons in all directions, including under the direction of the substrate. If the substrate area than the small LED light band gap, the substrate will absorb about half of the reflected light, which greatly reduces the light output. If a wafer with light-emitting diode bonded to a surface with high reflectivity of the wafer substrate, still able to heat the wafer substrate, fired at the substrate and the light will be reflected back through the emitter, which greatly increase the total light output.

Many materials such as silicon, gallium arsenide, gallium nitride, gallium phosphide, and sapphire, etc., can be used to produce LED. In the compound semiconductor layer grown on a photon and transfer to the silicon or similar material support wafer on the back and the wafer is exposed. Now only the big compound semiconductor to 4 inches. This limits the LED wafer and wafer with the size of only 2-4 inches in diameter. Another problem is the need to bond the two different crystal original hot

Expansion coefficient caused by bonding process is very slow. Because each time only a pair of wafer bonding, which limits the productivity of high-brightness LED, the unit cost is also high. These limits can be developed through the use of the new SUSS wafer bonding equipment to break through, the device can be synchronized multi-wafer bonding.

As raw materials to high-brightness GaN LED production in two ways: the gold - gold hot and gold tin eutectic bonding. In gold - gold hot bonding process, a layer of 1 to 3 micron thick gold bonding layer barrier is painted on each wafer. In order to eliminate surface contamination of solid-state diffusion mechanism, the need for cleaning steps (UV ozone or chemical wet processing). When bonding temperature is 250 ° to400 °, the pressure is 1 to 7MPa, from minutes to hours. Increase the time required temperature and pressure. If not enough time and pressure, usually between the wafer and wafer with only partial.

Sikkim eutectic method is the proliferation of solid and liquid through the formation of intermetallic compounds of the alloy to achieve bonding. Wafer coated with a thin layer of gold, while another wafer is coated with up to 5 micron thick gold tin. If necessary, diffusion barrier coating layer. To prevent oxidation of tin at high temperatures, wafer bonding to be carried out in gas, such as nitrogen and hydrogen mixed gas (95% N2, 5% H2) in the. This method only and the use of low melting point higher than the temperature of bonding can be completed in minutes.