Conductive Adhesive for Display Panel Substrate Bonding
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Solution Overview
Problem
Existing display devices face challenges in achieving reliable electrical connections between circuit substrates and display panels due to insufficient adhesion and high resistance values, particularly when using conductive adhesives with conductive particles that require high temperatures for bonding.
Innovation Solution
The use of a conductive adhesive comprising a polymer resin and conductive particles, such as tin or indium alloys, with a melting point between 60°C to 200°C, applied between driving and panel connecting substrates, and optionally including spacer particles, to ensure effective bonding and adhesion at lower temperatures, thereby increasing connection areas and reducing resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional conductive adhesives with high melting point particles are used, then bonding strength is achieved, but bonding temperature must be high causing damage to display panel components
Solution Approach 1:
The patent changes the material parameters of conductive particles by using low-melting-point alloys (e.g., In-Sn-Bi alloy with melting point of 60-200°C) instead of conventional high-melting-point particles. This parameter change enables bonding at lower temperatures (60-200°C) while maintaining adequate bonding strength, resolving the contradiction between bonding strength and bonding temperature.
Solution Approach 2:
The patent employs composite material structure consisting of polymer resin matrix combined with low-melting-point conductive particles (In-Sn-Bi alloy). This composite approach allows the adhesive to exhibit both adhesive properties from the polymer and conductive properties from the metal particles, while the low melting point of the alloy enables low-temperature processing.
2Reliability
If conductive adhesive with insufficient adhesion is used, then electrical connection is achieved, but connection reliability is poor
Solution Approach 1:
The patent uses a composite adhesive system where polymer resin provides strong adhesion to substrates while embedded conductive particles provide electrical conductivity. The In-Sn-Bi alloy particles with low melting point enhance wetting and bonding to pad surfaces, simultaneously improving both adhesion strength and electrical connection reliability.
Solution Approach 2:
The patent optimizes the composition parameters of the conductive particles by using specific In-Sn-Bi alloy ratios and controlling particle size distribution. This parameter optimization enhances the adhesive's ability to form reliable electrical connections while maintaining strong adhesion to the display panel and circuit board substrates.
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
This approach enhances the electrical connection reliability and adhesion between substrates, improving the display device's performance by reducing contact resistance and maintaining adhesion under various conditions, including high temperatures and humidity.
Implementation Method 1
a conductive adhesive comprising a polymer resin and conductive particles, such as tin or indium alloys, with a melting point between 60°C to 200°C
Data Source
AI summary
A display device includes a display panel divided into a display region and a non-display region, the display panel including a panel pad part on the non-display region, a driving circuit substrate including a driving pad part, the driving circuit substrate to provide a driving signal to the display panel, a panel connecting substrate including a first connecting pad part and a second pad part, the panel connecting substrate to electrically connect the display panel and the driving circuit substrate, a first adhesive member between the driving pad part and the first connecting pad part, and a second adhesive member between the panel pad part and the second connecting pad part. At least one of the first and second adhesive members is a conductive adhesive member including a polymer resin and a plurality of conductive particles including at least one of tin or indium.