Connector Mounting With ACJM and Reflow for Fine-Pitch Strength
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for surface-mounting electronic components using anisotropic conductive films (ACF) face challenges in maintaining joining strength due to weak adhesion, requiring high positioning accuracy and costly facility modifications, especially when mounting connectors with fine pitches.
Innovation Solution
An electronic component design incorporating a reinforcing metal fitting soldered to the substrate, combined with an anisotropic conductive joining member, allows for simultaneous reflow soldering and thermocompression, ensuring strong connections without the need for high-accuracy facility changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If ACF is used for mounting connector, then fine connections can be made, but joining strength becomes weak
Solution Approach 1:
The patent applies composite materials by combining ACF (anisotropic conductive film) with a reinforcing metal fitting. The ACF provides fine connection capability while the metal fitting provides mechanical strength. This composite approach allows both fine pitch connections and sufficient joining strength to be achieved simultaneously.
Solution Approach 2:
The reinforcing metal fitting acts as an intermediary element between the connector and the substrate. It mediates between the weak ACF bonding and the need for strong mechanical attachment, distributing mechanical loads away from the ACF while maintaining electrical connections through the ACF.
2Strength
If reinforcing metal fitting is provided to connector, then joining strength is improved, but positioning accuracy requirement increases
Solution Approach 1:
The patent segments the connector structure into distinct functional parts: the ACF contact area for electrical connections and the metal fitting area for mechanical reinforcement. This segmentation allows the ACF to be positioned with standard accuracy for fine connections while the metal fitting provides the necessary mechanical strength, reducing the overall positioning accuracy requirement.
3Adaptability or versatility
If both reflow soldering and thermocompression processes are performed, then mounting capability is improved, but process complexity increases
Solution Approach 1:
The patent merges the reflow soldering process and the thermocompression process into a single integrated process sequence. By performing both operations in one continuous flow without requiring separate equipment or facility modifications, the mounting capability is enhanced while process complexity is minimized.
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 method enables cost-effective, high-accuracy surface-mounting of electronic components with enhanced joining strength, reducing equipment costs and simplifying the mounting process.
Implementation Method 1
bumps of the IC chip are conductively connected to corresponding leads of the substrate by conductive particles of ACF
Implementation Method 2
the IC chip is pressed against the substrate by a heated head... the entire IC chip is caused to adhere to the surface of the substrate by the resin of ACF
Implementation Method 3
hot air is supplied to the substrate in the reflow oven... the solder melts and the electronic components are soldered
Data Source
AI summary
A connector includes lead parts and terminal parts to be connected to lands of a substrate, respectively. An anisotropic conductive joining member (ACJM) is mounted in a region where the lead parts are located. The ACJM is a resin in which solder particles are dispersed. The resin can melt at a temperature lower than the melting point of the solder particles. Cream solder is placed on the lands to be connected to the terminal parts. The substrate on which the connector is mounted is passed through a reflow oven to heat both the substrate and the connector. The connection between the terminal parts and the lands by reflow soldering and the connection between the lead parts and the lands via the ACJM are performed simultaneously with each other.