Interposer Package Corner Reinforcement Against Warpage Cracks
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Solution Overview
Problem
The increasing number of semiconductor devices on a silicon interposer leads to warpage and cracking due to thermal expansion differences, which can cause failures during temperature cycle tests, compromising the reliability of semiconductor packages.
Innovation Solution
Incorporating a dummy member on the interposer to cover corner portions and a sealing member that fills spaces between the devices and the dummy member, preventing bending stress and enhancing package reliability by acting as a barrier between the underfill and sealing members.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the number of semiconductor devices on the interposer is increased, then the functionality and performance of the package is improved, but warpage and cracking occur due to thermal expansion differences
Solution Approach 1:
A dummy member is introduced as an intermediary element between the semiconductor devices and the interposer substrate. This dummy member has a coefficient of thermal expansion that matches the interposer substrate, acting as a buffer that absorbs thermal stress and prevents cracking in the molded interposer during temperature cycling while allowing increased device density
Solution Approach 2:
The dummy member is strategically placed at specific locations (corners or edges) of the interposer where thermal stress concentration occurs. By providing localized reinforcement only where needed rather than uniformly across the entire interposer, the solution prevents cracking while maintaining overall package functionality and minimizing added complexity
2Productivity
If the area of the interposer is increased, then more semiconductor devices can be disposed, but warpage occurs due to difference in coefficients of thermal expansion
Solution Approach 1:
The dummy member serves as a mediator between the large-area interposer and the semiconductor devices. By matching the thermal expansion properties of the interposer substrate and positioning the dummy member at stress-prone locations, it compensates for thermal expansion differences across the large area, preventing warpage while enabling higher device density
Solution Approach 2:
The dummy member extends in the vertical dimension (thickness direction) to provide structural support and stress distribution. This vertical dimension adds mechanical stability to the large-area interposer, counteracting warpage tendencies that arise from increased planar area while maintaining the ability to accommodate more devices
3Reliability
If dummy members are added to cover corner portions, then reliability is improved by preventing cracks, but device complexity increases
Solution Approach 1:
Rather than modifying the entire interposer structure, the dummy member is applied locally only at corner or edge portions where cracking is most likely to occur. This localized approach improves reliability by addressing specific vulnerability points without adding complexity to the overall device architecture or manufacturing process
Solution Approach 2:
The dummy member is a simple, inexpensive structural element that can be easily fabricated and integrated into the packaging process. Its straightforward geometry and material composition make it a cost-effective solution that improves reliability without significantly increasing device complexity or manufacturing difficulty
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 solution effectively prevents cracks and improves the reliability of semiconductor packages by mitigating bending stress during temperature cycle tests, ensuring the integrity of the package structure.
Implementation Method 1
warpage may occur due to a difference in coefficients of thermal expansion (CTE) between individual components constituting the package
Data Source
AI summary
A semiconductor package includes a package substrate, an interposer provided on the package substrate, a plurality of semiconductor devices on the interposer and spaced apart from each other, and electrically connected to each other through the interposer, at least one dummy member on the interposer to cover at least one corner portion of the interposer and arranged spaced apart from a first semiconductor device among the plurality of semiconductor devices, and a sealing member contacting the interposer and filling a space between the first semiconductor device and the at least one dummy member so as to cover a first side surface of the first semiconductor device, a first side surface of the at least one dummy member, and an upper surface of the dummy member. A second side surface, opposite to the first side surface, of the at least one dummy member is uncovered by the sealing member.