Driver IC Bump Layout for Uniform Pressure Bonding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High-resolution liquid crystal display devices face challenges in ensuring reliable connections between driver ICs and terminals due to bending issues during thermal pressure bonding, leading to insufficient pressure on outermost bumps and potential bad connections.
Innovation Solution
The driver IC is designed with a rectangular plane having bumps disposed on opposite long sides, with varying distances between the IC edge and bumps to ensure uniform pressure distribution, and optionally incorporating dummy bumps to alleviate bending and enhance pressure bonding force.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the driver IC is thermally pressure-bonded to the TFT substrate, then the connection between bumps and terminals is established, but the driver IC bends causing insufficient pressure on outermost bumps
Solution Approach 1:
The patent introduces a recess portion in the driver IC at the position corresponding to the outermost bumps. This local structural modification creates a stress relief zone that prevents bending at critical areas during thermal pressure bonding, ensuring uniform pressure distribution across all bumps while maintaining connection reliability.
2Reliability
If the distance between terminals and driver IC edge is increased on the multiple-row side, then uniform pressure bonding force is achieved, but the device complexity increases
Solution Approach 1:
Instead of uniformly increasing distances across the entire driver IC, the patent applies a localized recess portion only at the critical outermost bump area. This targeted approach achieves uniform pressure bonding force where needed without unnecessarily increasing overall device complexity.
3Stability of the object's composition
If dummy bumps are added between input and output bumps, then bending is alleviated and pressure distribution is improved, but the device complexity increases
Solution Approach 1:
The patent uses a localized recess portion instead of adding dummy bumps across the entire structure. This recess is strategically placed only at the outermost bump position where bending stress is most severe, achieving flatness improvement without the complexity of multiple dummy bumps.
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 configuration ensures a more reliable and uniform pressure bonding force across all bumps, improving the connection reliability and preventing bad connections by distributing pressure more evenly, especially on the outermost bumps.
Implementation Method 1
A heated pressure bonding head is used to thermally pressure-bond the driver IC to the terminals with the ACF interposed therebetween
Implementation Method 2
After thermal pressure bonding, the conductive particles of the film ensure conductive connection between the bumps of the driver IC and the terminals
Data Source
AI summary
A display device made of a TFT substrate and a driver IC is configured to eliminate bad connection between them. On the driver IC connected to the TFT substrate, a first principal surface has first bumps formed along a first side having a first edge and second bumps formed along a second side opposite to the first side and having a second edge. The TFT substrate has first terminals and second terminals connected to the first and the second bumps, respectively. On a cross section taken perpendicularly to the first and the second sides, the first principal surface has a first area between the first and the second bumps and a second area between the second bumps and the second edge. The first and the second areas are bent toward the TFT substrate.