Wafer splitting method for avoiding generation of bicrystal

Abstract

The present invention relates to a wafer splitting method for avoiding the generation of bicrystal. The method comprises the following steps of: preparing a wafer to be split and preparing a splitting device, wherein the wafer is provided with a plurality of laser cutting lines which are cut off by the splitting device, and the laser cutting lines are intersected vertically. The splitting device comprises a chopper, a work table and two splitting tables which move relatively. The wafer is placed on the work table and the two splitting tables, and the chopper just faces a gap between the two splitting tables; then executing a splitting operation, carrying out splitting action on the laser cutting lines through the chopper, wherein after the chopper splits any one of the plurality of laser cutting lines, the splitting device chooses whether to change the gap between the two splitting tables or not; in each time of splitting a laser cutting line by the chopper, setting and changing the gap between the splitting tables according to a sequence of splitting such that the chopper does split the wafer, a crystal grain is avoided from generating a bicrystal phenomenon, and the excellent rate of technology is raised.

Description

technical field [0001] The invention relates to a processing method for cutting wafers, in particular to a processing method for improving the cutting yield of wafers. Background technique [0002] see figure 1 and figure 2 As shown, the wafer splitter is used to split the wafer 1 into individual grains for subsequent packaging operations. Before the wafer 1 is split, the horizontal and vertical Laser cutting line 2, the laser cutting line 2 on the wafer 1 is not broken, and it is connected to about two-thirds of its thickness, and then the wafer 1 is attached with a blue chip 3 (or white film), and then the 1 is covered with a protective film (not shown) for protection, and then sent to a wafer splitter through a fixing fixture 4 for splitting operation. [0003] The wafer splitter includes a worktable 5, a rivet 6, two splitting tables 7 and an image capture system 8. The workbench 5 clamps the fixture 4 and can move and rotate in the plane direction , the splitting k...

AI Technical Summary

Problems solved by technology

[0005] In this known wafer splitter, in the process of splitting, the gap between the two splitting platforms 7 is a fixed distance, so when the wafer 1 is continuously split and reduced in size, a wafer of a certain size Wafer 1 has insufficient force-bearing area, so it cannot effectively withstand the two splitting platforms 7 when splitting, that is, the rivet 6 cannot effectively split the wafer 1, and the crystal grains produced by it will have twin crystals. The phenomenon of (two crystal grains connected) will reduce the process yield, especially for the production of small and medium-sized grains, the situation of twin crystal phenomenon is more obvious and serious

[0006] If the gap between the two splitting stations 7 is directly reduced, the twin crystal phenomenon can be improved, but when the gap between the two splitting stations 7 is too small, when the wafer 1 of the general size is split, the resulting crystal The grains are prone to cracking, oblique cracking and other problems, which will also reduce the excellent rate of the process

Images