Thermoplastic Protective Sheet Forming for Precise Wafer Thickness
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for placing protective members on workpieces, such as semiconductor wafers, are tedious and time-consuming, and the use of thermoplastic resins can lead to thickness inaccuracies due to heat expansion from pressing members.
Innovation Solution
A method involving a sheet producing step where a thermoplastic resin is heated and gripped in multiple directions to form a sheet-like protective member, followed by an integrating step to bond it to the workpiece, allowing for precise thickness control and easy removal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a pressing member is used to press thermoplastic resin against the support table, then the protective member can be formed, but the pressing member expands with heat causing thickness inaccuracies
Solution Approach 1:
The patent extracts the harmful pressing action from the heating process. Instead of pressing the thermoplastic resin against a support table during heating, the resin is heated while suspended or held in a mold cavity without contact pressure, eliminating the source of heat expansion errors.
Solution Approach 2:
The patent performs preliminary shaping of the thermoplastic resin in a mold cavity before the actual bonding process. The resin is pre-formed to the desired thickness and shape while cooling, then transferred to the workpiece for bonding, avoiding subsequent pressing operations that would cause expansion.
2Reliability
If thermoplastic resin is heated and pressed to form a protective member, then bonding is achieved, but it becomes tedious and time-consuming to peel off the protective member
Solution Approach 1:
The patent creates local quality differences in the bonding interface. The thermoplastic resin bonds strongly to the workpiece surface while maintaining weak adhesion to the mold or support structure, enabling selective release. The bonding characteristics are localized to specific interfaces through controlled contact and cooling.
Solution Approach 2:
Instead of pressing the protective member onto the workpiece and then trying to remove it, the patent inverts the process by forming the protective member in a mold first, then transferring it to the workpiece. The release occurs naturally during transfer rather than requiring forceful peeling afterward.
3Ease of operation
If adhesive tape is used to hold the workpiece, then the workpiece can be secured, but adhesive residuals remain on the workpiece when peeled off
Solution Approach 1:
The patent changes the physical parameters of the bonding material from adhesive chemistry to thermoplastic phase transitions. The thermoplastic resin transitions from solid to molten state during heating for bonding, then solidifies upon cooling, providing holding capability without residual contamination. The bonding mechanism changes from chemical adhesion to physical interlocking through phase change.
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
The method reduces the time and effort required to peel off the protective member and minimizes the adverse effects of heat on the resin, ensuring accurate thickness and efficient integration with the workpiece.
Implementation Method 1
heating a plate-shaped thermoplastic resin to soften or melt the plate-shaped thermoplastic resin
Implementation Method 2
heating and bringing the sheet-like protective member into intimate contact with the workpiece to integrate the workpiece and the protective member with each other
Data Source
AI summary
A method of placing a protective member on a workpiece includes a sheet producing step of heating a plate-shaped thermoplastic resin to soften or melt the same while gripping and pulling outer edges of the thermoplastic resin in at least four directions to produce a sheet-like protective member, and after the sheet producing step, an integrating step of heating and bringing the sheet-like protective member into intimate contact with the workpiece to integrate the workpiece and the protective member with each other.