Separation method of metal substrate light-emitting device wafer

Abstract

The invention discloses a separation method of a metal substrate light-emitting device wafer. The method comprises the steps that a metal substrate is provided, the front face of the substrate is connected with a light-emitting device array through a metal connecting layer, an auxiliary pattern is formed on the back face of the metal substrate, a laser beam is focused on the back face of the substrate, the back face of the substrate is ablated under the guidance of the auxiliary pattern, splitting is conducted on the front face of the substrate along gaps of the light-emitting array, and light-emitting devices are separated. Due to the fact that laser is cut on the back face, the influence of the laser on the front-face light-emitting device is small, and yield loss caused by laser cuttingcan be reduced.

Description

technical field [0001] The invention relates to a preparation process of a light-emitting device on a metal substrate, in particular to a method for separating a wafer of a light-emitting device on a metal substrate. Background technique [0002] Because of its good thermal conductivity, ductility and electrical conductivity, metal substrates have certain applications in vertical structure light-emitting devices. At present, metal substrate vertical structure LEDs perform well under high current conditions. It is widely used in the lighting market. After the light-emitting device is prepared, the device on the metal substrate needs to be separated. This separation method has an important impact on the yield of the device. [0003] For wafers with metal substrates, the method of laser cutting the front side of the wafer is generally used to separate devices, such as image 3 with Figure 4 shown. However, due to the high power of the laser cutting metal substrate, the tempe...

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Problems solved by technology

However, due to the high power of the laser cutting metal substrate, the temperature of the laser ablation area is very high instantaneously, and the gap between the light-emitting devices is generally designed to be tens of microns to more than one hundred microns due to cost factors, and the heat in the ablation area Conducted over a short distance of tens of microns on the surface of the substrate, resulting in a higher temperature in the light-emitting area. In addition, metal debris from laser cutting is easy to splash into the light-emitting area, which increases the risk of device leakage. When laser cutting the front side, it is usually coated Protective fluid to reduce the risk of splashing metal residue from laser ablation, but it cannot be completely avoided

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