Dummy Pad Mitigates Thermal Stress in Semiconductor Packages
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Solution Overview
Problem
Semiconductor packages face challenges in minimizing warpage and cracking due to differences in thermal expansion coefficients of materials, leading to defects and reliability issues in highly integrated System-in-Package (SiP) structures.
Innovation Solution
Incorporating a dummy pad made of metal material between semiconductor chips on a package substrate, which overlaps at least a portion of each chip and is covered by a molding member, to prevent warpage and cracking by minimizing thermal stress.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple semiconductor chips are densely integrated within a single package to reduce overall volume, then productivity and data processing capacity are improved, but warpage and cracking due to thermal expansion coefficient differences occur
Solution Approach 1:
A dummy pad made of metal material with appropriate thermal expansion coefficient is introduced as an intermediary element between the semiconductor chips and the package substrate. This dummy pad acts as a stress buffer that absorbs thermal expansion mismatches, preventing warpage and cracking while allowing dense integration of multiple chips to maintain high productivity
2Weight of stationary object
If semiconductor chips are arranged closely to minimize package size, then weight reduction is achieved, but thermal stress from material expansion differences causes cracking
Solution Approach 1:
The dummy pad is strategically positioned in specific locations where thermal stress concentrates, creating a local quality enhancement in the stress distribution. This allows the package to maintain compact dimensions for weight reduction while the localized dummy pad structures prevent cracking in critical areas
3Productivity
If different types of semiconductor chips are mounted in a single package to provide high-capacity data processing, then productivity is improved, but the complexity of managing thermal expansion differences increases
Solution Approach 1:
The dummy pad serves multiple functions simultaneously: it acts as a stress buffer for thermal expansion, provides structural support for chip mounting, and facilitates heat dissipation. This multi-functionality allows different types of semiconductor chips to be integrated in a single package without significantly increasing overall package complexity
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 dummy pad effectively inhibits cracking and enhances the reliability and productivity of semiconductor packages by addressing thermal expansion coefficient disparities, thereby protecting internal components and improving the overall integrity of the package.
Implementation Method 1
differences in thermal expansion coefficients of materials, leading to defects and reliability issues
Data Source
AI summary
A semiconductor package includes semiconductor chips on a package substrate, and a dummy pad disposed between and the semiconductor chips and overlapping at least a portion of the semiconductor chips. The dummy pad being disposed on the package substrate and in a space between the package substrate and the semiconductor chips.