Dry Microfiber Adhesive for Residue-Free Wafer Temporary Bonding
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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 or specialized equipment.
Innovation Solution
A dry adhesive comprising an array of micro- or nano-scale fibers with enlarged tips that 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 additional processing steps and contamination risk increase
Solution Approach 1:
The patent extracts the harmful liquid adhesive material and replaces it with a dry adhesive system using microfiber arrays. This eliminates the need for liquid application, curing steps, and chemical debonding processes, directly resolving the contradiction between bonding strength and processing complexity
Solution Approach 2:
The patent replaces chemical bonding mechanisms (liquid adhesive) with a mechanical bonding mechanism (microfiber array physical contact and entanglement). The microfibers mechanically interlock with the wafer surface, providing strong bonding without chemical substances, thus eliminating additional processing steps
2Ease of operation
If heat is used for debonding, then debonding effectiveness is improved, but substrate warping and yield loss increase
Solution Approach 1:
The patent replaces thermal debonding with a mechanical debonding mechanism. The microfiber array allows debonding through simple mechanical peeling or parallel movement, eliminating heat application entirely. This prevents substrate warping and maintains yield, while still achieving effective debonding
Solution Approach 2:
The patent changes the debonding parameter from temperature (thermal energy) to mechanical force (peeling force). By controlling the peeling force and angle, effective debonding is achieved without thermal effects that cause substrate warping and yield loss
3Ease of operation
If pressure sensitive adhesive tape is used, then ease of application is improved, but residue and additional cleaning steps increase
Solution Approach 1:
The patent extracts the adhesive material from the bonding system and replaces it with a dry microfiber array. This eliminates residue generation entirely, as there is no adhesive material to leave behind. The microfibers are designed to be removable without leaving any contaminants on the wafer surface
Solution Approach 2:
The patent employs a disposable microfiber array that is used once and then discarded. This eliminates residue issues entirely, as the bonding medium itself is removed with the wafer or carrier, leaving no behind. The single-use nature ensures no residue contamination
4Reliability
If bonding strength is increased for secure attachment, then attachment reliability is improved, but damage risk during debonding increases
Solution Approach 1:
The patent introduces dynamic control of bonding strength through the microfiber array structure. The bonding strength can be adjusted by controlling the peeling angle and force during debonding. At shallow angles, strong bonding is maintained for secure attachment; at optimal peeling angles, the bonding strength reduces smoothly, preventing damage while maintaining attachment reliability during processing
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 by minimizing residue and eliminating the need for complex debonding processes.
Implementation Method 1
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, in which 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, and, a liquid can be introduced to the interface between the dry adhesive and semiconductor device to adjust the force of adhesion.