Semiconductor Wafer Dicing Using Rear-Surface Adhesive Cutting
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Solution Overview
Problem
The dicing-before-grinding process for semiconductor wafers often results in poor alignment of semiconductor chips, potential damage from cutting, and contamination or cracking due to the use of blades or lasers for cutting the adhesive film, leading to issues like partial cutting of wiring regions and surface dirt or chip cracking during handling.
Innovation Solution
A method involving the formation of cutting grooves on a semiconductor wafer, application of a protection tape, grinding to divide the wafer, forming an adhesive layer, and cutting the adhesive layer using high-pressure air while melting or softening it, which prevents partial cutting and surface contamination, and ensures stable chip separation without cracking.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a diamond blade or laser is used to cut the adhesive layer from the front surface side, then the adhesive layer can be separated, but wiring regions may be partly cut and surfaces may get dirty due to cutting chips
Solution Approach 1:
The patent inverts the cutting direction by performing the cutting process from the rear surface side of the semiconductor wafer instead of the conventional front surface side. This allows the adhesive layer to be cut without interfering with the wiring regions on the front surface, thereby preventing partial cutting of wiring and surface contamination while maintaining ease of manufacture
Solution Approach 2:
The patent introduces a rear surface processing approach as an intermediary method. By accessing and cutting the adhesive layer from the rear surface, the process avoids direct contact between cutting tools and the front surface wiring regions, thus preventing damage while still achieving effective adhesive layer separation
2Manufacturing precision
If high-pressure air is sprayed to the adhesive layer while melting or softening it by heating, then cutting precision is improved and contamination is prevented, but additional heating equipment is required
Solution Approach 1:
The patent combines the heating function and high-pressure air spraying function into a single integrated processing step. The heating unit and high-pressure air supply unit work simultaneously to melt/soften the adhesive layer while cutting it, achieving precise cutting and contamination prevention without requiring separate complex equipment systems
Solution Approach 2:
The patent changes the physical state of the adhesive layer by heating it to a melting or softening point, and simultaneously applies high-pressure air to exploit the changed viscosity and flow properties. This parameter change enables cleaner cutting with better precision while the combined system manages the complexity through coordinated parameter control
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method ensures precise cutting of semiconductor chips with the adhesive layer ends wrapped around the side surfaces, preventing 'sink' and 'projection' issues, and effectively prevents metal ion contamination by covering the side surfaces, enhancing machining speed and stability while maintaining chip integrity.
Implementation Method 1
spraying a high-pressure air to the adhesive layer formed on the rear surface of the semiconductor wafer while melting or softening the adhesive layer by heating
Implementation Method 2
spraying a high-pressure air to the adhesive layer formed on the rear surface of the semiconductor wafer while melting or softening the adhesive layer by heating
Data Source
AI summary
According to one embodiment, a manufacturing method of a semiconductor device is disclosed. The method includes: (a) forming cutting grooves in an element formation surface of a semiconductor wafer on which semiconductor elements are formed; (b) applying a protection tape on the element formation surface of the semiconductor wafer; (c) grinding a rear surface of the semiconductor wafer to thin the semiconductor wafer and to divide the semiconductor wafer into a plurality of semiconductor chips on which the semiconductor elements are formed; (d) forming an adhesive layer on the rear surface of the semiconductor wafer; (e) separating and cutting the adhesive layer for each of the semiconductor chips; and (f) removing the protection tape. The (e) is performed by spraying a high-pressure air to the adhesive layer formed on the rear surface of the semiconductor wafer while melting or softening the adhesive layer by heating.