Chamfered Substrate Structure for Semiconductor Package Stress Relief
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Solution Overview
Problem
Conventional semiconductor packaging techniques face issues with stress concentration at chip corners and mismatched thermal expansion coefficients, leading to cracks and delamination, which reduce product yield, especially in thinner and more compact electronic devices.
Innovation Solution
A substrate structure with chamfers and recesses is designed to distribute stress and enhance bonding between the substrate and packaging layers, using conductive bodies and encapsulating materials to prevent cracks and delamination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional semiconductor packaging is used with rectangular substrates, then the packaging process is simple and manufacturing is easy, but stress concentration occurs at corners causing cracks and delamination
Solution Approach 1:
The substrate corners are modified from conventional rectangular shapes to include chamfers (beveled edges) and/or rounded corners, creating an asymmetric geometry that redistributes stress away from corner points. This asymmetric design prevents stress concentration while maintaining manufacturing feasibility through standard PCB fabrication processes.
Solution Approach 2:
The corner regions of the substrate are given special geometric treatment (chamfers or rounding) different from the rest of the substrate body. This local modification addresses the specific stress concentration problem at corners without changing the overall substrate design or manufacturing process complexity.
2Adaptability or versatility
If mismatched thermal expansion coefficients are present between wafer, TSI and package substrate, then material selection is flexible and cost is reduced, but delamination occurs during temperature cycling
Solution Approach 1:
The chamfered or rounded corner design creates a gradual transition zone at substrate corners, providing localized stress relief that compensates for thermal expansion mismatches between different materials (wafer, TSI, package substrate) during temperature cycling.
3Volume of moving object
If thinner and more compact electronic products are designed, then product size is reduced and market competitiveness is improved, but stress concentration effects are amplified causing higher failure rates
Solution Approach 1:
The asymmetric corner geometry (chamfers or rounding) is particularly effective in compact devices where absolute dimensions are small, as the relative stress distribution improvement provides greater protection against failure in thinner, more compact packages.
Data Source
AI summary
Provided is a substrate structure, including a substrate having at least one chamfer formed on a surface thereof, and a plurality of conductive bodies formed to the substrate. Therefore, a stress generated during the packaging process is alleviated through the chamfer, and the substrate structure is prevented from being cracked. An electronic package employing the substrate structure is also provided.