Submicron Silver Adhesive for Die-Bonding Heat Dissipation
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Solution Overview
Problem
There is a need for a thermally conductive, electrically conductive adhesive composition that provides high thermal conductivity and consistent electrical conductivity for use as a die-bonding material, particularly for electronic components that generate increasing heat due to their smaller size and higher functionality, while being lead-free and cost-effective.
Innovation Solution
A thermally conductive, electrically conductive adhesive composition comprising submicron fine silver powder as the electrically conductive filler, epoxy resin, and a specific curing agent, with the curing agent being a compound that controls the curing rate to promote the formation of an adequate network of electrically conductive fillers for improved heat dissipation and electrical conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If high-temperature lead solder or gold-tin solder is used as bonding material, then excellent heat dissipation properties are achieved, but lead contamination or high cost occurs
Solution Approach 1:
The patent changes the material composition parameters by using submicron fine silver powder (75-94% by mass) combined with specific epoxy resin and curing agent formulations, achieving high thermal conductivity without lead or gold, thus resolving the contradiction between heat dissipation performance and environmental safety/cost
Solution Approach 2:
The patent creates a composite adhesive material combining submicron fine silver powder with epoxy resin and specific curing agents, achieving both excellent heat dissipation properties and electrical conductivity while being lead-free and cost-effective, resolving multiple contradictions simultaneously
2Reliability
If submicron fine silver powder is used as electrically conductive filler, then electrical conductivity and thermal conductivity are improved, but manufacturing complexity increases
Solution Approach 1:
The patent specifies precise parameter ranges for submicron fine silver powder particle size and content (75-94% by mass), along with controlled curing agent equivalents (0.4-2.4 molar equivalents), achieving consistent electrical conductivity while providing clear manufacturing guidelines that balance performance with manufacturability
3Temperature
If high proportion of electrically conductive filler is used, then thermal conductivity and electrical conductivity are enhanced, but adhesive strength may be reduced
Solution Approach 1:
The patent formulates a composite material with submicron fine silver powder (75-94% by mass) combined with specific epoxy resin and curing agent ratios, achieving both high thermal conductivity and adequate adhesive strength through optimized composition, resolving the contradiction between conductivity enhancement and strength maintenance
Solution Approach 2:
The patent optimizes the particle size parameter of submicron fine silver powder and its content ratio (75-94% by mass), along with curing agent equivalents (0.4-2.4 molar equivalents), achieving a balance between thermal conductivity enhancement and adhesive strength retention
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 composition achieves excellent heat dissipation and consistent electrical conductivity at a low cost, with the submicron fine silver powder and controlled curing agent ensuring effective thermal and electrical conductivity.
Implementation Method 1
an electrically conductive filler (A), an epoxy resin (B), and a curing agent (C), as described above, as essential components. The reason why the adhesive composition of the present invention has excellent heat dissipation properties is not necessarily clear but is speculated that, because of the lowered curing rate of the adhesive composition, distribution of the electrically conductive filler within the epoxy resin as a binder resin is improved than normal and, as a result, necking of the electrically conductive filler is promoted to allow the dispersed electrically conductive filler to fuse with each other during heat curing
Implementation Method 2
An electrically conductive adhesive is a composite of a metal particle having functions such as electrical conductivity (silver, nickel, copper, aluminum, or gold, for example) and an organic adhesive that functions as adhesive
Implementation Method 3
the curing agent (C) being a compound of Formula (I), (II), or (III), and the content of the compound being 0.4 to 2.4 molar equivalents in terms of equivalent of active hydrogen relative to 1 molar equivalent of epoxy groups in the epoxy resin (B)
Data Source
AI summary
[PROBLEMS TO BE SOLVED] A thermally conductive, electrically conductive adhesive composition having high thermal conductivity and consistent electrical conductivity for use as a die-bonding material is provided. [SOLUTION] A thermally conductive, electrically conductive adhesive composition including: (A) an electrically conductive filler, (B) an epoxy resin, and (C) a curing agent, the electrically conductive filler (A) being a submicron fine silver powder, and the content of the fine silver powder being 75 to 94% by mass of the total amount of the thermally conductive, electrically conductive adhesive composition, the content of the epoxy resin (B) being 5 to 20% by mass of the total amount of the thermally conductive, electrically conductive adhesive composition, the curing agent (C) being a compound of Formula (I), (II), or (III), and the content of the compound being 0.4 to 2.4 molar equivalents in terms of equivalent of active hydrogen relative to 1 molar equivalent of epoxy groups in the epoxy resin (B), and during heat curing and before the electrically conductive filler (A) starts to sinter, the thermally conductive, electrically conductive adhesive composition being in an uncured state or a half-cured state: (in which X is -SO2-, -CH2-, or -O-, and R1 to R4 are independently a hydrogen atom or a lower alkyl group), (in which X is -SO2-, -CH2-, or -O-, and R5 to R8 are independently a hydrogen atom or a lower alkyl group), and (in which X is -SO2-, -CH2-, or -O-, and R9 to R12 are independently a hydrogen atom or a lower alkyl group).