Polyimide Adhesive Layer for Heat-Resistant Semiconductor Transfer
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Solution Overview
Problem
Existing methods for bonding semiconductor elements to heat-dissipating substrates require high temperature and pressure, making them inefficient for high-volume processing, and pressure-sensitive adhesives used for transfer and mounting face challenges with heat resistance and adhesiveness, leading to issues like residual material and difficulty in transferring small devices.
Innovation Solution
A pressure-sensitive adhesive composition comprising a polyimide copolymer with specific diamine residues and a dimer acid epoxy resin, along with a crosslinking agent, which provides high adhesiveness and heat resistance, enabling the simultaneous transfer and mounting of multiple semiconductor elements under high-temperature conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If high temperature and pressure are applied to bond semiconductor elements directly to heat-dissipating substrates, then heat dissipation performance is improved, but processing time increases due to sequential bonding requirements
Solution Approach 1:
The patent applies preliminary action by pre-coating the substrate with a pressure-sensitive adhesive layer before mounting semiconductor elements. This allows elements to be transferred and mounted simultaneously in one step without requiring sequential high-temperature bonding operations, thus improving productivity while maintaining heat dissipation performance
Solution Approach 2:
The pressure-sensitive adhesive layer serves as an intermediary between the heat-dissipating substrate and semiconductor elements. It enables simultaneous transfer and mounting operations at lower temperatures while still achieving effective thermal contact, resolving the contradiction between bonding temperature and processing speed
2Ease of operation
If conventional pressure-sensitive adhesives are used for transfer and mounting, then ease of operation is improved, but heat resistance deteriorates leading to residual material and transfer difficulties
Solution Approach 1:
The patent uses a composite pressure-sensitive adhesive composition containing a polyimide copolymer with specific diamine residues (including aromatic diamine and aliphatic diamine components) and a dimer acid epoxy resin. This composite structure combines the pressure sensitivity needed for easy transfer operations with the heat resistance required to prevent degradation and residual material formation at high temperatures
Solution Approach 2:
The patent modifies the chemical composition parameters of the pressure-sensitive adhesive by specifying particular diamine residue ratios (aromatic diamine 20-80 mol%, aliphatic diamine 20-80 mol%) and incorporating dimer acid epoxy resin at controlled ratios. These parameter changes enhance heat resistance while preserving the pressure-sensitive properties needed for easy transfer and mounting operations
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 allows for efficient, high-volume transfer and mounting of semiconductor elements with reduced residual material and improved heat resistance, facilitating the bonding process without damaging the elements.
Implementation Method 1
it has also been disclosed that if a crosslinking agent is added to the polyimide copolymer containing siloxanes in its structure, it works to improve its chemical resistance
Implementation Method 2
A pressure sensitive adhesive comprising a polyimide copolymer (A) having at least an acid dianhydride residue and a diamine residue and also comprising a dimer acid epoxy resin (B)
Data Source
AI summary
The present invention aims to provide a pressure sensitive adhesive having high pressure sensitive adhesiveness and heat resistance and serves to makes it possible to transfer and mount a large number of semiconductor elements at once even when the process involves a step for applying heat to the semiconductor elements. It provides a pressure sensitive adhesive including a polyimide copolymer (A) having at least an acid dianhydride residue and a diamine residue and also comprising a dimer acid epoxy resin (B), wherein the diamine residue has a diamine residue (A1) as represented by the formula (1) in which n is a natural number of 1 or more and 15 or less (hereinafter referred to as the diamine residue (A1)), a diamine residue (A2) as represented by the formula (1) in which n is a natural number of 16 or more and 50 or less (hereinafter referred to as the diamine residue (A2)), and a diamine residue (A3) having a phenolic hydroxyl group (hereinafter referred to as the diamine residue (A3)) and also wherein the diamine residue (A1) accounts for 50.0 mol % or more and 95.0 mol % or less, the diamine residue (A2) accounting for 1.0 mol % or more and 40.0 mol % or less, and the diamine residue (A3) accounting for 1.0 mol % or more and 30.0 mol % or less, of all diamine residues, which account for 100.0 mol %, in the polyimide copolymer (A).