Stealth Dicing Processing Method

Stealth dicing processing consists of 2 steps. In a first step, which is a laser processing process, a laser beam form SD layers inside the wafer by laser processing. In a second step, which is a separation process, a tensile stress is applied to start points in SD layer to split the wafer.

Each process is briefly described below.

ステルスダイシング加工方法

1. Laser processing process

In the laser processing process, a laser beam scans along the pre-planned dicing line on the wafer affixed by tape, forming an SD layer internally in the wafer. Stealth dicing allows processing optional positions within the wafer by using a dedicated laser and optical system. This means that the processing forms no debris or damage on the front and back side surfaces and no purified water is needed for washing. Stealth dicing can be performed in a completely dry process. A dedicated AF function also allows high-speed operation.

レーザ加工工程

This laser processing is performed by dicing machine with stealth dicing.

2.Separation process

Separation process

In the separation process, an external force such as tape expansion is applied to the wafer that has now been laser-machined to form the SD layer along the preplanned SD lines. This force or expansion creates cracks that extend perpendicularly from the SD layer towards the front and back sides of the wafer, splitting it into individual chips. Crack extension causes the wafer to split so that cutting loss is essentially zero. It is therefore possible to allow the split surface to approach the active area or to separate ultra-thin wafers and MEMS wafers into chips without applying mechanical stress.

The above 2 processes are essentially what makes up stealth dicing.

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