Polyimide Copolymer Adhesive for Semiconductor Wafer Bonding
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Solution Overview
Problem
Existing temporary-bonding adhesives for semiconductor devices face challenges such as adhesive force changes during processing, solder bump melting during heating, and material decomposition under high temperatures, limiting their effectiveness in bonding and de-bonding semiconductor substrates efficiently.
Innovation Solution
A polyimide copolymer with specific polysiloxane-based diamine residues is used, which forms a single-type adhesive layer providing excellent heat resistance and allowing for mechanical de-bonding or solvent dissolution at room temperature, ensuring consistent adhesive force throughout the manufacturing process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a polyamide-based or polyimide-based adhesive layer is used to provide heat resistance, then heat resistance is improved, but adhesive force varies during processing making de-bonding difficult
Solution Approach 1:
The patent applies parameter changes by modifying the chemical composition parameters of the adhesive layer. Specifically, it uses a polyimide copolymer with controlled ratios of different diamine components (aromatic diamine, alicyclic diamine, and polysiloxane-based diamine) to achieve both heat resistance and consistent adhesive force. The specific compositional parameters (mole ratios of different diamines) are optimized to prevent adhesive force variation during processing while maintaining heat resistance.
2Ease of operation
If heating is applied to de-bond the adhesive layer, then de-bonding is achieved, but solder bumps melt causing device failure
Solution Approach 1:
The patent replaces the thermal de-bonding mechanism with a mechanical de-bonding mechanism. Instead of using heat to break the adhesive bonds (which causes solder bump melting), the invention designs an adhesive layer that can be mechanically separated at room temperature. This is achieved through specific polymer chain structures and intermolecular forces that allow clean mechanical separation without thermal degradation of sensitive components.
Solution Approach 2:
The patent utilizes phase transition principles by designing the adhesive layer to undergo a reversible transition from a bonded state during processing to a separable state during de-bonding. The adhesive maintains strong bonding characteristics at processing temperatures but transitions to a state that allows easy mechanical separation at room temperature, avoiding the need for reheating that would melt solder bumps.
3Reliability
If adhesive force is increased to prevent de-bonding during processing, then bonding reliability is improved, but de-bonding becomes impossible without damaging components
Solution Approach 1:
The patent applies dynamics by creating an adhesive layer with dynamic bonding characteristics that adapt to different process stages. The adhesive exhibits strong bonding force during semiconductor processing to prevent accidental de-bonding, but is designed to allow controlled mechanical separation afterward. This dynamic behavior is achieved through specific polymer structures that maintain bond integrity under processing conditions but permit clean separation when mechanically initiated.
4Device complexity
If a single-type adhesive layer is used to simplify the structure, then device complexity is reduced, but heat resistance and de-bonding performance may be compromised
Solution Approach 1:
The patent applies composite materials by creating a polyimide copolymer that combines multiple diamine components within a single adhesive layer structure. Rather than using separate adhesive layers for different functions, the invention integrates aromatic diamine, alicyclic diamine, and polysiloxane-based diamine components into one copolymer structure. This composite approach provides both heat resistance and controlled de-bonding performance while maintaining a single-layer simple structure.
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 solution enables reliable bonding and de-bonding of semiconductor substrates with consistent adhesive force and heat resistance, preventing voids and fractures, and facilitating efficient semiconductor device manufacturing.
Implementation Method 1
heat resistance enough to endure a semiconductor step is required of the temporary-bonding adhesive
Implementation Method 2
an adhesive force is varied by heating, and thereby the semiconductor circuit formation substrate is de-bonded off
Implementation Method 3
a step of reworking an adhesive layer or a residue of an adhesive layer respectively remaining on the semiconductor circuit formation substrate or the support substrate with an organic solvent, an alkaline aqueous solution or the like
Data Source
AI summary
The present invention provides a temporary-bonding adhesive having excellent heat resistance, whereby a semiconductor circuit formation substrate and a support substrate can be bonded by a single type of adhesive layer, the adhesive force thereof does not change over the course of steps for manufacturing a semiconductor device or the like, and the adhesive can subsequently be easily de-bonded at room temperature under mild conditions; and a method for manufacturing a semiconductor device using the temporary-bonding adhesive. The present invention includes a temporary-bonding adhesive wherein a polyimide copolymer having at least an acid dianhydride residue and a diamine residue, the diamine residue including both of (A1) a polysiloxane-based diamine residue represented by a general formula (1) in which n is a natural number from 1 to 15, and (B1) a polysiloxane-based diamine residue represented by a general formula (1) in which n is a natural number from 16 to 100, the polyimide copolymer containing 40-99.99 mol % of the (A1) residue and 0.01-60 mol % of the (B1) residue.