Wafer laminated body cutting method for image sensor

Abstract

PROBLEM TO BE SOLVED: To provide a cutting method of an image sensor wafer package which allows for clear cutting effectively by a simple dry technique, without using a dicing saw.SOLUTION: In a cutting method of a wafer laminate W for image sensor having a structure where a glass wafer 1 and a silicon wafer 2 are bonded via a resin layer 4 arranged to surround each photodiode forming region, a scribe line S consisting of a crack penetrating in the thickness direction is formed, by rolling a scribing wheel 10, while pressing, along a cutting line on the upper surface of the glass wafer. Subsequently, the wafer laminate is deflected by pressing a break bar 14 from the lower surface side of the silicon wafer along the scribe line, thus cutting the silicon wafer along with the glass wafer.

Description

technical field [0001] The present invention relates to a dicing method for singulating a wafer laminated body of a wafer level package (WLP) patterned with a CMOS image sensor. Background technique [0002] In recent years, the use of CMOS image sensors has increased rapidly in the field of various small electronic devices such as mobile phones, digital cameras, and optical mice that emphasize low power, high performance, and high integration. [0003] Figure 5 It is a cross-sectional view schematically showing a configuration example of a wafer-level package (chip-sized unit product) W1 of a CMOS image sensor. The wafer level package W1 has a laminated structure in which a (singulated) glass wafer 1 and a (singulated) silicon wafer 2 are bonded with resin barrier ribs 4 interposed therebetween. [0004] A photodiode (photodiode) formation region (sensing region) 3 is formed on the upper surface (joint surface side) of the silicon wafer 2, and is arranged in such a manner...

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Problems solved by technology

[0012] The above-mentioned cutting saw is divided by cutting with a rotating blade, so a large amount of cutting chips are generated, and even if it is cleaned with cutting fluid, for example, there is still a part of the cutting fluid remaining, or it is caused by scattering during cutting. Adhesion of cutting chips to the surface of the package, etc., becomes a major cause of quality or yield reduction

In addition, since a mechanism or piping is required for supplying cutting fluid or collecting waste fluid, the scale of the device becomes large.

In addition, since the glass wafer is divided by cutting, there are many cases of small chips (defects) on the cutting surface, and it is impossible to obtain a perfect dividing surface.

In addition, since the tip of the blade of the rotary blade rotating at high speed is formed in a sawtooth shape, abrasion or breakage of the tip of the blade is likely to occur and the service life is short.

Furthermore, since the thickness of the rotary blade cannot be set to be relatively thin in terms of strength, and even a small diameter has a thickness of 60 μm or more, the existence of a cutting width is not only necessary but also becomes one of the factors that limit the effective use of materials other problems

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