Conductive Adhesive Composition With Delayed Curing for Filler Bonding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conductive adhesives used in electronics assembly often have insufficient adhesive strength due to the thermosetting resin curing too quickly, hindering the bonding of conductive fillers, and there is a need for lead-free alternatives to solder.
Innovation Solution
A conductive adhesive composition featuring a bismaleimide resin with a reaction initiation temperature of 180°C or higher, combined with a filler and catalyst, to ensure smooth bonding of fillers and substrates, along with a flux to facilitate melting and bonding, and a polymer component for enhanced film formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a thermosetting resin is used in conductive adhesive, then adhesive strength is improved, but curing occurs too quickly which hinders filler bonding
Solution Approach 1:
The patent changes the key parameter of reaction initiation temperature to 180°C or higher, which delays the onset of curing compared to conventional resins. This parameter modification allows the adhesive to remain workable longer during application while still achieving strong bonding, resolving the contradiction between adhesive strength and curing speed.
2Strength
If curing of thermosetting resin progresses quickly, then adhesive strength is improved, but bonding of conductive filler is hindered
Solution Approach 1:
By setting the reaction initiation temperature at 180°C or higher, the patent creates a temporal window where filler bonding can occur before resin curing begins. This parameter change ensures that conductive particles can properly bond to substrates and to each other without being hindered by premature resin crosslinking, thereby maintaining both adhesive strength and filler bonding reliability.
3Object-affected harmful factors
If lead-free solder is used, then environmental harm is reduced, but adhesive strength is insufficient
Solution Approach 1:
The patent employs a composite material system combining a bismaleimide thermosetting resin with specific conductive fillers (such as silver particles) and curing agents. This composite formulation achieves both environmental compatibility by eliminating lead and superior adhesive strength through the synergistic interaction of resin, filler, and curing agent, where the high reaction initiation temperature ensures proper filler bonding.
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 provides superior adhesive properties and conductivity without using harmful substances, ensuring strong bonding between fillers and substrates, even at higher temperatures, making it effective for low-melting point solders.
Implementation Method 1
a thermosetting resin, wherein the thermosetting resin is a bismaleimide resin... and at least one catalyst or curing agent, wherein the reaction initiation temperature for the thermosetting resin and the at least one catalyst or curing agent is 180°C or higher
Implementation Method 2
the bonding of the filler may be hindered if the curing of the thermosetting resin progress more quickly than the melting and bonding of the conductive filler
Data Source
Figure 1~2
AI summary
A conductive adhesive that does not contain toxic substances such as solder (lead) and shows excellent adhesiveness is provided. Specifically, it is a conductive adhesive composition, which comprises (A) a thermosetting resin; (C) a filler that contains a metal element; and (D) at least one catalyst or curing agent, wherein the reaction initiation temperature for the (A) thermosetting resin and the (D) at least one catalyst or curing agent is 180°C or higher. More preferably, the reaction initiation temperature is 200°C or higher. More preferably, it is a conductive adhesive composition that further comprises (B) a flux and (E) a polymer component.