Sinterable Silver Resin Composition to Prevent Delamination
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Solution Overview
Problem
Sinterable conductive compositions often compromise on physical properties like flexibility and strength to achieve higher conductivity, leading to issues such as brittleness and delamination during temperature cycling, especially in large die applications.
Innovation Solution
A composition comprising 2-15% thermosetting resin, 65-93% silver particles, 1-10% fillers, and a silane adhesion promoter, where the binder resin is not fully cured at the onset of silver sintering, ensuring a partially cured state during sintering, resulting in a shear strength of at least 25 kg/mm² at 260°C and thermal conductivity of 70 W/m·K.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If greater filler loadings are implemented to achieve higher conductivity, then electrical conductivity is improved, but brittleness increases and strength decreases
Solution Approach 1:
The patent changes the curing state parameter of the binder resin during sintering. By controlling the binder resin to be in a partially cured or uncured state at the onset of silver sintering, and completing curing after sintering, the composition achieves both high conductivity (70 W/m·K) and high strength (≥25 kg/mm² shear strength), resolving the trade-off between conductivity and strength
Solution Approach 2:
The patent creates a composite material system combining silver particles, binder resin, and curing agent where the interaction between components is temporally controlled. The composition leverages the complementary properties of silver (conductivity) and cured resin (strength), achieving both high conductivity and mechanical strength through proper sequencing of sintering and curing processes
2Reliability
If greater filler loadings are implemented to achieve higher conductivity, then electrical conductivity is improved, but the composition becomes more brittle
Solution Approach 1:
The patent changes the curing state parameter of the binder resin during sintering. By controlling the binder resin to be in a partially cured or uncured state at the onset of silver sintering, and completing curing after sintering, the composition achieves both high conductivity (70 W/m·K) and high flexibility, resolving the trade-off between conductivity and flexibility
Solution Approach 2:
The patent introduces temporal dynamics to the binder resin state. The binder resin transitions from a flexible uncured/partially cured state during sintering to a rigid cured state after sintering, allowing the composition to achieve both flexibility during processing and structural stability in the final product
3Stability of the object's composition
If the binder resin is fully cured at the onset of silver sintering, then structural stability is improved, but delamination occurs during temperature cycling
Solution Approach 1:
The patent inverts the conventional sequence by delaying binder resin curing until after silver sintering. Instead of curing the resin before or during sintering (which causes delamination), the resin is kept uncured or partially cured during sintering and only cured afterward, preventing delamination while maintaining structural stability
Solution Approach 2:
The patent applies beforehand cushioning by maintaining the binder resin in an uncured or partially cured state during the sintering process. This creates a flexible buffer that accommodates thermal expansion and contraction during temperature cycling, preventing delamination before it can occur
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 composition achieves improved conductivity, flexibility, and strength, preventing delamination and maintaining reliability during temperature cycling, while maintaining thermal conductivity and adhesion strength.
Implementation Method 1
when heated to a temperature at which the silver powder and silver flake starts to sinter
Implementation Method 2
a binder resin comprising a thermosetting resin (such as desirably one or more epoxy monomers, oligomers, or polymers); a silane adhesion promoter; and a curing agent
Data Source
AI summary
Provided herein is an electrically conductive composition capable of sintering. More particularly, the electrically conductive composition comprises sinterable silver particles dispersed in a binder resin, which binder resin is not yet in a fully cured state when the composition is heated to a temperature at which the silver particles start to sinter.