Unique Transparent Resin and Vacuum Printing Encapsulation Systems (VPES) Packaging Method for New White LED

Abstract

As you know, (light emitting diode) industry is full of vigor. They are used by signal, car, and backlight of mobile telephone and so on. In particular, white color attracts attention very much, If it is applied to lighting equipments in future, it is certain that it becomes a very big market. In general, colorless transparent resin is used by transparent epoxy resin, but there are many problems of materials fitting white color LED. Because blue is emitting high temperature and UV light from chip itself. In recently, it appears high power chip LED through large electric current for these applications. This means that the transparent resin deterioration becomes very fast. Therefore, it is a fact that quality declines. So that we solve this difficult problem, we investigated materials except epoxy resin such as silicon resin and hybrid resin. And we developed special transparent epoxy resin, too. We get very good result after humidity test (85degC/85%/1000 hr/20 mA). However, a problem comes out to materials (silicon resin), the materials choice is necessary by specifications. We prepare some materials matching for each PCB material and each reliability condition. Secondly, we suggest high density packaging technology using VPES. These good advantages are very fine pitch and low height, high density packaging technology, good mass production, and low cost systems. Shape of made by VPES is very unique shape. For example, it has a characteristic that a field of vision corner is very large. We expect that this technology apply to new high power LED applications. In the main subject, we will take up backlight for LCD. You will understand how this technology is tied to energy saving.