Semiconductor Package Ring-Lid Structure for CTE Stress Relief
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Solution Overview
Problem
The coefficient of thermal expansion (CTE) mismatch between materials in semiconductor packages leads to thermal stress, causing delamination, warpage, and die cracks, which are not effectively addressed by existing technologies.
Innovation Solution
A semiconductor package design featuring a ring structure with a cantilever portion bonded between the semiconductor device and the lid structure, enhancing bonding strength and thermal performance by using materials with different CTEs and thermal conductivities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If materials with different CTEs are used in semiconductor packages, then thermal performance is improved, but thermal stress causes delamination, warpage, and die cracks
Solution Approach 1:
The package structure is divided into multiple layers including substrate, semiconductor device, underfill material, and lid structure, each with different CTE properties. This segmentation allows gradual CTE transition and stress distribution across interfaces, reducing the harmful effects of CTE mismatch while maintaining thermal performance.
Solution Approach 2:
The patent modifies the CTE parameters of materials used in the package structure. Specifically, the underfill material is designed with intermediate CTE values between the substrate and lid structure, creating a gradient that reduces thermal stress. This parameter optimization allows better thermal management while preventing delamination and warpage.
2Strength
If bonding area is increased to improve bonding strength, then bonding strength is improved, but package complexity increases
Solution Approach 1:
The bonding area is extended from a single-plane configuration to a multi-dimensional structure. The underfill material creates additional bonding interfaces between layers, and the lid structure incorporates extended bonding surfaces that wrap around the semiconductor device. This dimensional expansion increases bonding strength without significantly increasing overall package complexity.
Solution Approach 2:
The patent uses composite material structures with multiple bonding interfaces. The underfill material acts as an intermediate composite layer that bonds to both the substrate and lid structure, creating a multi-layer composite system. This approach distributes bonding stresses across multiple interfaces and material combinations, enhancing overall bonding strength while maintaining manufacturing feasibility.
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 design reduces delamination and warpage, improves bonding strength, and enhances thermal performance by optimizing the CTE mismatch between materials, thereby stabilizing the semiconductor package.
Implementation Method 1
The coefficient of thermal expansion (CTE) mismatch between materials in semiconductor packages leads to thermal stress, causing delamination, warpage, and die cracks
Implementation Method 2
a thermal interface material disposed between the contact portion and the semiconductor device for thermally coupling the semiconductor device and the lid structure
Data Source
AI summary
A semiconductor package includes a substrate, a semiconductor device disposed over the substrate, a ring structure bonded to the substrate, and a lid structure. The ring structure includes a main portion surrounding the semiconductor device and a cantilever portion extended toward the semiconductor device and bonded to a top surface of the semiconductor device. The lid structure is bonded to the ring structure and includes a contact portion bonded to the top surface of the semiconductor device.