Polyimide Adhesive Laser Debonding Semiconductor Workpieces
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Solution Overview
Problem
Current temporary bonding adhesives for semiconductor workpieces face challenges in achieving excellent adhesion, heat resistance, and removability, especially during high-temperature semiconductor processes, and require effective debonding and cleaning methods.
Innovation Solution
A method involving a polymer-based adhesive with a light absorbing material and specific chemical structures, which forms a strong bond through thermal compression and can be easily debonded using laser separation, allowing for stable workpiece fixation and easy removal post-processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If conventional temporary bonding adhesives are used for high-temperature semiconductor processes, then heat resistance is improved, but adhesion and removability deteriorate
Solution Approach 1:
The patent uses a composite adhesive system comprising a polyimide base resin combined with specific functional additives including silane coupling agents and reactive diluents. This composite formulation creates a material that simultaneously achieves high-temperature stability (heat resistance) while maintaining strong adhesion to semiconductor substrates and enabling controlled removability through laser irradiation or chemical dissolution.
Solution Approach 2:
The adhesive formulation incorporates components with specific glass transition temperatures and thermal decomposition characteristics. By carefully selecting polyimide derivatives with appropriate Tg values and combining them with curing agents that activate at specific temperature ranges, the adhesive maintains flexibility and bonding strength during high-temperature processing while allowing for controlled debonding when exposed to laser energy or specific solvents.
2Reliability
If strong bonding is achieved for stable workpiece fixation, then adhesion is improved, but ease of removal deteriorates
Solution Approach 1:
The patent introduces a light-absorbing intermediate component within the adhesive formulation that acts as a mediator between the strong bonds formed during processing and the easy removal required afterward. When laser irradiation is applied, this intermediate component absorbs the energy and converts it to thermal energy, locally heating the adhesive to a point where bond rupture occurs easily, thus enabling clean removal without damaging the substrate or workpiece.
Solution Approach 2:
The adhesive system is designed with a specific molecular structure that allows selective extraction or decomposition of the bonding component under certain conditions. The polyimide backbone provides strong adhesion during processing, but when exposed to specific solvents or laser energy, the bonding moieties can be selectively broken down or dissolved, separating the adhesive from the substrates while leaving minimal residue.
3Ease of operation
If laser debonding is implemented for easy removal, then removability is improved, but cleaning difficulty worsens
Solution Approach 1:
The adhesive formulation incorporates a light-absorbing component distributed non-uniformly or at specific depths within the adhesive layer. When laser irradiation is applied, this creates localized heating primarily at the adhesive-substrate interface or within specific regions of the adhesive, enabling precise debonding without excessive heat generation that would carbonize the adhesive and create difficult-to-remove residues. The local concentration of light-absorbing material ensures energy is deposited where needed for bond rupture rather than throughout the entire adhesive volume.
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 provides excellent adhesion and heat resistance during high-temperature processes, enabling stable bonding and easy debonding and cleaning, with improved laser debond ability and washability, suitable for semiconductor applications.
Implementation Method 1
an adhesive with laser debond
Implementation Method 2
the adhesive is heated so as to convert the adhesive into the adhesive layer
Implementation Method 3
the temporary bonding adhesive needs the heat resistance and the removability
Data Source
Figure 1~2
Figure 3A
Figure 3B
AI summary
A method for temporary bonding workpiece includes steps as follows. A combining step is performed, wherein an adhesive layer (330) is formed on a surface of at least one substrate (310) and/or at least one workpiece (320). A bonding step is performed, wherein the substrate and the workpiece are bonded by the adhesive layer. A processing step is performed, wherein the workpiece is processed. A debonding step is performed, wherein the adhesive layer is irradiated with a laser so as to separate the workpiece from the substrate. The adhesive layer is formed by an adhesive, the adhesive includes a polymer and a light absorbing material, a content of the polymer in a solid content of the adhesive is in a range of 50 wt% to 98 wt%, a content of the light absorbing material in the solid content of the adhesive is in a range of 2 wt% to 50 wt%.