Interposer Dam and Elastic Stress Relief for Package Warpage
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Solution Overview
Problem
Semiconductor packages face issues with warpage and peeling due to differences in thermal expansion coefficients between components, leading to stress increases between material interfaces.
Innovation Solution
A semiconductor package design incorporating a molded interposer with an elastic stress relief member and a dam structure extending along the interposer's peripheral region, which reduces stress and enhances rigidity, thereby preventing peeling and warpage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a high density interconnection using a silicon interposer is used, then the performance and bandwidth are improved, but warpage occurs due to difference in coefficients of thermal expansion
Solution Approach 1:
The patent changes the material parameter of the interposer from rigid silicon to compliant material (such as epoxy resin or polymer) that can accommodate thermal expansion differences. This parameter change allows the interposer to flex and absorb stress during thermal cycling, preventing warpage while maintaining electrical interconnection functionality.
Solution Approach 2:
The patent uses composite material structures including the compliant interposer combined with rigid substrates and protective encapsulants. This composite approach balances the structural requirements for high-density interconnection with the need to accommodate thermal expansion mismatches between different components.
2Adaptability or versatility
If different materials are stacked together, then functionality is improved, but peeling occurs due to increase in stress between interfaces
Solution Approach 1:
The patent changes the mechanical parameter of the interposer material from rigid to compliant, which allows it to deform and absorb stress at interfaces. This prevents stress concentration that would otherwise cause peeling between differently expanded materials during thermal cycling.
Solution Approach 2:
The compliant interposer acts as a flexible element between rigid substrates and components. This flexible layer can bend and deform to accommodate dimensional changes, maintaining intimate contact at interfaces and preventing peeling while allowing different materials to be stacked together.
3Manufacturing precision
If rigid structures are used for high density interconnection, then manufacturing precision is improved, but stress concentration increases leading to reliability issues
Solution Approach 1:
The patent changes the mechanical property parameter of the interposer from rigid to compliant while maintaining the precision of electrical interconnections. The compliant material allows for stress absorption without compromising the alignment and connection precision required for high-density interconnections.
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 reduces stress between different material interfaces, preventing peeling and warpage, and improves the reliability of the semiconductor package by increasing its overall rigidity.
Implementation Method 1
a stress relief on the interposer, the stress relief including an elastic member that fills gaps between the semiconductor devices and the dam structure
Data Source
AI summary
A semiconductor package includes a package substrate, an interposer on the package substrate, a plurality of semiconductor devices on the interposer and spaced apart from each other, the semiconductor devices being electrically connected to the interposer, a dam structure on the interposer extending along a peripheral region of the interposer, the dam structure being spaced apart from the semiconductor devices, and a stress relief on the interposer, the stress relief including an elastic member that fills gaps between the semiconductor devices and the dam structure.