Dry Adhesive Microfiber Array for Residue-Free Wafer Debonding
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Solution Overview
Problem
Existing semiconductor manufacturing processes face challenges in efficiently bonding and debonding silicon wafers to carriers without causing contamination, residue, or damage, particularly in wafer level packaging, where current methods like liquid adhesives and pressure-sensitive tapes are inefficient and require additional processing steps.
Innovation Solution
A dry adhesive comprising an array of micro- or nano-scale fibers with enlarged tips that can adhere to silicon wafers, allowing for adjustable bond strength and debonding through peeling or parallel movement, with optional wetting to enhance adhesion for easy removal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If liquid adhesive is used for temporary bonding, then bonding strength is improved, but processing complexity and contamination risk increase
Solution Approach 1:
The patent extracts the adhesive material from the wafer bonding process entirely, replacing liquid adhesives with a dry adhesive transfer tape system. The adhesive is pre-applied to the tape rather than the wafer, eliminating the need for spin coating, curing, and chemical debonding steps, thus reducing processing complexity while maintaining bonding strength.
Solution Approach 2:
The patent introduces an intermediary adhesive transfer tape that mediates between the wafer and carrier. The tape serves as a temporary bonding interface that can be easily applied and removed without affecting the wafer or carrier, simplifying the overall bonding process while providing sufficient adhesion strength.
2Strength
If liquid adhesive bonding is used, then bonding strength is improved, but debonding time and contamination risk increase
Solution Approach 1:
The patent removes the time-consuming debonding processes (chemical solvents, high-temperature heating, or laser treatment) by using a dry adhesive tape that can be simply peeled off. The adhesive bonds strongly during processing but releases easily during debonding, eliminating the need for lengthy debonding procedures.
Solution Approach 2:
The adhesive properties are made dynamic through the transfer tape system. The adhesive bonds strongly under normal conditions during wafer processing but can be easily deactivated for removal by simple mechanical peeling, allowing the bonding strength to adapt to different process stages without requiring additional time or resources.
3Ease of operation
If pressure sensitive adhesive tape is used, then ease of operation is improved, but residue and contamination increase
Solution Approach 1:
The patent uses a disposable adhesive transfer tape that is designed to be used once and then discarded. The tape provides the necessary bonding function during wafer processing and is then easily removed without leaving residue. The tape itself becomes the disposable element that absorbs any potential contamination rather than the wafer or carrier.
Solution Approach 2:
The patent extracts the residue and contamination issues from the wafer processing system by confining them to the adhesive transfer tape. The tape is designed to capture any adhesive residue on its own surface rather than transferring it to the wafer, eliminating contamination risks while maintaining ease of operation.
4Strength
If existing adhesive methods are used, then bonding strength is determined by material properties, but adaptability to different applications decreases
Solution Approach 1:
The patent enables parameter changes in bonding strength by selecting different adhesive materials for the transfer tape. The adhesive properties (such as tack, bonding strength, and temperature range) can be adjusted by choosing appropriate adhesive formulations, allowing the same basic transfer tape system to adapt to different wafer sizes, materials, and processing conditions.
Solution Approach 2:
The adhesive transfer tape system provides universal applicability across different semiconductor manufacturing applications. The same basic system can be used for bonding wafers to carriers, handling diced dies, or transferring packaged modules, with only the adhesive material needing to be adjusted for specific requirements, thus achieving multi-functionality.
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 dry adhesive provides efficient bonding and debonding at room temperature, reducing contamination and damage risks, simplifying processing, and increasing throughput while enabling high yields.
Implementation Method 1
an array of micro- or nano-scale fibers extending from a surface, where the fibers have an enlarged, shaped tip. The tips make contact with the surface of the wafer and provide an adhesion force
Implementation Method 2
the dry adhesive is affected by wetting, which can increase the force of adhesion. As a result, introducing a liquid, such as water or isopropyl alcohol, can be used to adjust the adhesion properties of the adhesive
Data Source
AI summary
A dry adhesive microfiber array comprising a plurality of fibers with enlarged tips, where the dry adhesive is capable of adhering to a surface of a silicon wafer and/or carrier. The dry adhesive can be debonded without the use of chemicals or heat and does not leave a residue on the surface of the wafer. In addition, a liquid can be introduced to the interface between the dry adhesive and semiconductor device to adjust the force of adhesion.