A novel wafer thinning method

Abstract

According to a novel wafer thinning method, polytetrafluoroethylene is added into a polyimide solution which is to be rolled and stirred uniformly to form coating liquid; the coating liquid is coated on the front surface of an original wafer to cover the surface of the original wafer and chamfers between the front surface of the original wafer and edges to form a cover layer; otherwise, a polytetrafluoroethylene coating or a UV coating is made to cover the front surface of the original wafer and subjected to low-temperature baking to enable a cover layer to form on the surface of the original wafer and the chamfers between the front surface of the original wafer and edges to form a cover layer; coarse grinding and fine grinding are carried out on the original wafer according to present technology; illumination is carried out to enable cracking of the cover layer; and plasma cleaning is carried out to remove the cracked cover layer so as to obtain the thinned wafer. The thinning method can prevent secondary pollution to the surface of the wafer in a thinning process; the wafer thinning quality and the test yield rate can be raised; cleaning by a lot of water is not needed; a lot of water resources are saved; and a good basis is provided for subsequent pressure welding technology.

Description

technical field [0001] The invention belongs to the technical field of semiconductor packaging for electronic device manufacturing, and relates to a wafer thinning method, in particular to a novel wafer thinning method. Background technique [0002] From the cross-sectional structure of integrated circuits, most integrated circuits are manufactured on the shallow surface layer of silicon base material. The integrated circuit manufacturing process puts forward high requirements on the dimensional accuracy, geometric accuracy, surface cleanliness and surface microlattice structure of the wafer. Therefore, in hundreds of processes, thinner wafers cannot be used, and only wafers of a certain thickness can be used to transfer and tape out during the process. Usually, before the integrated circuit is packaged, it is necessary to remove a certain thickness of base material from the backside of the wafer. This process is called wafer backside thinning process, and the correspondin...

AI Technical Summary

Problems solved by technology

During the process of filming on the wafer surface, the edge of the wafer cannot be tightly attached to the film, plus the individual bubbles formed by the film, the mixture of particles formed during wafer thinning and cooling water (sewage) along the film The gap between the edge of the wafer and the wafer penetrates to the surface of the wafer, and the sewage drills into the surface of the wafer, especially the small particles are difficult to clean, which not only affects the test yield, but also needs to be cleaned with a large amount of water

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