Polycarbonate Pre-Sintering Sheet for Low-Residue Bonding
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Solution Overview
Problem
The use of thermosetting adhesives in securing chips to substrates often results in unreliable power modules due to residual organic substances in the sintered body, which can lead to reduced electrical conduction and reliability during temperature cycling testing.
Innovation Solution
A composite sheet with a pre-sintering layer comprising polycarbonate and metal particles is used, where the polycarbonate effectively undergoes pyrolysis during sintering, minimizing the amount of residual organic substances and enhancing the reliability of the sintered body.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If epoxy resin is used in the film for sintering, then the film can be formed and sintered, but a large amount of organic substances remain in the sintered body, reducing electrical conduction and reliability
Solution Approach 1:
The patent changes the chemical composition parameter of the binder from epoxy resin to polycarbonate, which fundamentally alters the pyrolysis behavior during sintering. Polycarbonate decomposes more completely at sintering temperatures, significantly reducing residual organic substances in the sintered body and improving electrical conduction and reliability.
Solution Approach 2:
The patent converts the potential harm of residual organic substances into a benefit by selecting polycarbonate as the binder. Polycarbonate's specific pyrolysis characteristics ensure that organic substances are effectively removed during sintering, transforming the sintering process from a source of contamination into a purification step that enhances product quality.
2Strength
If thermosetting adhesive is used to secure chips to substrate, then chips can be bonded, but reliability is not ensured during temperature cycling testing
Solution Approach 1:
The patent changes the material composition of the adhesive layer by using polycarbonate as the binder instead of conventional thermosetting adhesives. This parameter change enables the adhesive to withstand temperature cycling better while maintaining bonding strength, as polycarbonate's pyrolysis characteristics reduce residual organics that would otherwise degrade under thermal stress.
3Object-generated harmful factors
If polycarbonate is used as the binder in the pre-sintering layer, then residual organic substances are reduced, but the manufacturing process becomes more specific
Solution Approach 1:
The patent specifies polycarbonate as the binder material with particular molecular weight ranges (10,000-1,000,000) and composition requirements. While this increases material selection specificity, it simplifies the overall manufacturing process by eliminating the need for complex post-sintering treatments to remove residual organics, as polycarbonate naturally decomposes cleanly during standard sintering.
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 approach results in a sintered body with significantly reduced organic residues, improving the reliability of power modules during temperature cycling testing and maintaining effective electrical conduction.
Implementation Method 1
polycarbonate will more effectively undergo pyrolysis as a result of sintering than would be the case with epoxy resin
Data Source
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AI summary
A problem is to provide a sheet which is such that a sintered body produced following sintering has a small amount of remaining organic substances. Solution means relate to a sheet comprising a pre-sintering layer. The pre-sintering layer comprises polycarbonate.