Wafer Processing Using Polyolefin Sheet for Clean Cutting
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Solution Overview
Problem
The existing wafer processing methods generate cutting dust from adhesive tapes, which adheres to device chips, leading to quality degradation during the cutting process.
Innovation Solution
A wafer processing method using a polyolefin sheet without an adhesive layer for thermocompression bonding with the wafer and ring frame, allowing for clean cutting and easy removal of cutting dust, and facilitating the pickup of device chips with reduced load.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If adhesive tape is used to hold the wafer during cutting, then the wafer can be securely held and cut along division lines, but cutting dust from the adhesive layer adheres to device chips causing quality degradation
Solution Approach 1:
The invention extracts and removes the adhesive layer from the tape structure, using only the non-adhesive base layer to hold the wafer. This eliminates the source of adhesive cutting dust that adheres to device chips, while the base layer alone provides sufficient holding stability for the cutting process
Solution Approach 2:
The invention uses a disposable non-adhesive tape that is discarded after the cutting process. The tape holds the wafer during cutting, then is removed and discarded, eliminating the need for cleaning adhesive dust from device chips and avoiding quality degradation
2Ease of manufacture
If adhesive tape is used to hold the wafer, then the wafer can be processed, but the adhesive layer generates harmful cutting dust that is difficult to remove
Solution Approach 1:
The adhesive layer is extracted and removed from the tape structure, eliminating the generation of adhesive cutting dust during the wafer cutting process, while the non-adhesive base layer maintains sufficient holding capability for processing
Solution Approach 2:
The invention converts the potentially harmful adhesive layer into a beneficial non-adhesive structure. By removing the adhesive properties, the cutting dust generated is non-adhesive and easily removed, transforming a harmful factor into a beneficial outcome
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
Prevents cutting dust adherence to device chips, thereby suppressing quality degradation and ensuring reliable cleaning and handling of device chips.
Implementation Method 1
heating the polyolefin sheet as applying a pressure to the polyolefin sheet after performing the polyolefin sheet providing step, thereby uniting the wafer and the ring frame through the polyolefin sheet by thermocompression bonding
Data Source
AI summary
A wafer processing method includes a polyolefin sheet providing step of positioning a wafer in an inside opening of a ring frame and providing a polyolefin sheet on a back side of the wafer and on a back side of the ring frame, a uniting step of heating the polyolefin sheet as applying a pressure to the polyolefin sheet to thereby unite the wafer and the ring frame through the polyolefin sheet by thermocompression bonding, a dividing step of cutting the wafer by using a cutting apparatus to thereby divide the wafer into individual device chips, and a pickup step of heating the polyolefin sheet, pushing up each device chip through the polyolefin sheet, and then picking up each device chip from the polyolefin sheet.