Processing method of wafer

Abstract

Provided is a wafer processing method for dividing a wafer in which a chip mounting layer is laminated on the back surface, reducing the number of separation channels, shortening the processing time,and efficiently breaking the chip mounting layer. The wafer processing method includes: a wafer dividing step of performing plasma etching on a wafer (W) with a mask (J1) having an opening along a planned dividing line (S) interposed therebetween, and dividing the wafer to form chips (C); a sheet attaching step of laminating a chip mounting layer (T2) on the back surface (Wb) of the wafer before or after the wafer dividing step is performed, and attaching the wafer to the expansion sheet (T1) with the chip mounting layer interposed therebetween; a solvent providing step of providing a solventfor degrading the chip mounting layer between adjacent chips from the front surface (Wa) side of the wafer after the wafer dividing step and the wafer pasting step are performed, and degrading the chip mounting layer exposed between the chips; and a breaking step of breaking the chip mounting layer along the etching groove (M) by expanding the expansion sheet after the solvent supply step is performed.

Description

Technical field [0001] The present invention relates to a method for processing a wafer having a die attach layer laminated on the back surface. Background technique [0002] In order to reduce the width of the spacer channel (pre-divided line) set on the front side (decrease the spacer channel) and increase the number of chips per wafer and to shorten the processing time, so-called plasma cutting has been used in the past. The wafer of the workpiece is divided (for example, refer to Patent Document 1). [0003] In addition, in order to mount a semiconductor chip formed by dividing a semiconductor wafer on a mounting substrate, there is a technique of attaching a DAF (Die Attach Film) to the back surface of the semiconductor wafer in advance. In the adhesive film of, the chip is bonded to the mounting substrate via the adhesive film on the back surface of the divided chip (for example, refer to Patent Document 2). In this technology, DAF is attached to the wafer before the wafer ...

AI Technical Summary

Problems solved by technology

[0008] In plasma etching, the so-called BOSCH method is widely used, and it is suitable for realizing vertical deep processing of wafers at high speed and with a desired aspect ratio (for example, refer to Patent Document 3). However, for the etching gas used in the BOSCH method, there are The problem that DAF is not easily etched or not etched

[0009] In addition, a device for breaking DAF by expansion has been proposed (for example, refer to Patent Document 4), but when the chip size is reduced to, for example, several millimeters or less, there is a problem that it is not easy to separate by expansion.

[0010] It is also considered to use a laser processing device to disconnect the DAF, but there are the following problems: In a wafer with a small chip size, there are many lines to be laser processed, which takes processing time and reduces efficiency.

[0011] Accordingly, when dividing a wafer on which a die attach layer (DAF) is stacked on the back surface, there is a problem in that the die attach layer can be efficiently divided while reducing the spacer and shortening the processing time. open

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