Cutting method of wafer grade white-light LED chip

Abstract

The invention provides a cutting method of a wafer grade white-light LED chip. The method comprises the steps of preparing a vertical structural GaNLED wafer chip by the substrate transfer process; cutting a cutting channel in the front surface of the wafer through laser to form a concave groove; coating a fluorescent coating on the wafer chip; baking and solidifying; thinning the rear surface of the wafer chip; evaporating a back metal layer; performing back cutting for the wafer chip through a blade, wherein the cutting position is corresponding to the concave groove in the front surface; splitting along the concave groove in the wafer ship to obtain single white-light LED chip. With the adoption of the method, the wafer grade white-light LED chip can be smoothly separated without damaging the fluorescent glue layer on the surface of the LED chip, so that the phenomena of breaking and cracking in the traditional cutting process can be avoided, and the yield of white-light LED can be increased.

Description

technical field [0001] The invention relates to the field of production and preparation of light-emitting diodes. More specifically, the present invention relates to a cutting method of wafer-level white light LED chips. Background technique [0002] Usually, the manufacturing method of realizing white light LED is to fix a single GaN blue light chip on the bracket by packaging technology, and obtain white light LED after wiring, dotting fluorescent glue or spraying fluorescent glue. The process of producing white light LEDs is complicated, and the light output efficiency of the chip is low, and because the consistency of the thickness of the fluorescent glue on the chip surface is difficult to control, the light emission of LED products is uneven, which adds difficulties to the secondary optical design. [0003] In order to solve the problems in conventional methods, a method for preparing wafer-level white LED chips has emerged. The method is obtained by using a fluoresc...

AI Technical Summary

Problems solved by technology

If the wafer-level white LED chip is cut with a blade, the fluorescent adhesive layer will stick to the blade, causing a series of defects such as damage to the fluorescent adhesive on the chip surface, rolling up of the metal on the substrate, and cracking of the substrate, which will affect the quality of the product. Yield and Reliability

Although laser cutting can avoid the above problems, the laser will burn the side of the fluorescent adhesive layer black, causing light absorption and reducing the brightness of the white LED chip

Images