UV-Debondable Adhesive Tape for Semiconductor Wafer Dicing
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Solution Overview
Problem
Conventional pressure-sensitive adhesive tapes used in semiconductor wafer processing exhibit insufficient adhesive strength during cutting operations, leading to dice drop-off and difficulty in peeling off from the carrier substrate, with issues of adhesive residue and material scattering.
Innovation Solution
A pressure-sensitive adhesive tape comprising a support layer, adhesive layer, and peeling layer, with solid components including a self-crosslinking acrylic resin, acrylate monomers or oligomers, an isocyanate cross-linking agent, and a photo-initiator, allowing the adhesive layer to be de-glued by UV light through a cross-linking and curing reaction initiated by a photo-initiator after UV exposure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional pressure-sensitive adhesive tape is used to mount the wafer, then the wafer can be adhered to the carrier substrate, but the adhesive strength is insufficient leading to dice drop-off during cutting operation
Solution Approach 1:
The adhesive layer uses a composite formulation containing acrylic resin, isocyanate cross-linking agent, and photoinitiator. This multi-component system creates a composite material that provides both initial adhesive strength for mounting and enables subsequent UV-induced cross-linking to enhance bonding reliability during cutting operations.
Solution Approach 2:
The adhesive properties are dynamically changed through UV irradiation. Before UV exposure, the adhesive maintains pressure-sensitive bonding characteristics for easy application. After UV irradiation, the photoinitiator triggers cross-linking reactions that fundamentally alter the adhesive parameters, increasing bond strength and preventing dice drop-off during cutting.
2Strength
If the adhesive strength between the pressure-sensitive adhesive tape and the carrier substrate is increased after UV exposure, then the bonding becomes overly strong, but the pressure-sensitive adhesive tape becomes difficult to peel off without leaving residual adhesive
Solution Approach 1:
The adhesive system transitions from a static bonding state to a dynamic, controllable state. UV irradiation acts as a switch that transforms the adhesive from pressure-sensitive (easy to peel) to cross-linked (strong bonding). This dynamic control allows optimization of both initial mounting ease and final bonding strength, resolving the contradiction between peelability and bonding strength.
Solution Approach 2:
The adhesive bonding process occurs in distinct periodic stages: first, pressure-sensitive application for mounting; second, UV irradiation for cross-linking enhancement. This periodic action sequence allows the system to achieve both easy initial application and strong final bonding without residual adhesive issues.
3Ease of operation
If the adhesive layer undergoes cross-linking and curing reaction after UV irradiation, then the adhesive strength is reduced for easy peeling, but the cross-linking process requires additional processing time
Solution Approach 1:
The mechanical peeling process is replaced by a photochemical cross-linking mechanism. Instead of relying on mechanical force to overcome adhesive bonds, UV light initiates a chemical reaction that fundamentally changes the adhesive properties. This substitution enables rapid transformation of adhesive characteristics without extended mechanical processing time.
Solution Approach 2:
The photoinitiator is pre-incorporated into the adhesive layer formulation during manufacturing. This preliminary action ensures that when UV irradiation occurs, the cross-linking reaction can immediately commence without requiring additional preparation steps, thereby minimizing processing time while achieving complete cross-linking for optimal peelability.
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 adhesive tape effectively reduces adhesive strength post-UV exposure, facilitating easy peeling and preventing adhesive residue, suitable for semiconductor wafer processing by ensuring dice pickup without damage.
Implementation Method 1
After the adhesive layer is irradiated by the ultraviolet light, the photo-initiator generates free radicals with abilities to initiate polymerization
Implementation Method 2
the self-crosslinking acrylic resin, the acrylate monomers or the oligomers, and the isocyanate cross-linking agent undergo the cross-linking and curing reaction, so that an adhesion of the adhesive layer is reduced
Data Source
AI summary
A pressure-sensitive adhesive tape, a method for producing the same, and a method for using the same are provided. The pressure-sensitive adhesive tape includes a support layer, an adhesive layer, and a peeling layer. Solid components of the adhesive layer include a self-crosslinking acrylic resin, acrylate monomers or oligomers of the acrylate monomers, an isocyanate cross-linking agent, and a photo-initiator. Before the adhesive layer is irradiated by ultraviolet light, the acrylate monomers or the oligomers do not undergo a cross-linking and curing reaction. After the adhesive layer is irradiated by the ultraviolet light, the photo-initiator generates free radicals with abilities to initiate polymerization, and the self-crosslinking acrylic resin, the acrylate monomers or the oligomers, and the isocyanate cross-linking agent undergo the cross-linking and curing reaction, so that an adhesion of the adhesive layer is reduced.