Semiconductor Package Structure With Corner Stress-Relief Trenches
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The challenge in semiconductor packaging lies in managing tensile stress at the corners of semiconductor dies, which can lead to cracking of underfill materials and reduced reliability of 3D packaging structures, especially due to differences in thermal expansion coefficients between the substrate and the dies.
Innovation Solution
Incorporating trenches in the substrate under the open corners of the semiconductor dies and filling them with underfill material, which extends into the substrate, mitigates tensile stress and reduces the risk of cracking, thereby enhancing the package structure's performance and reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If trenches are added to the substrate under the open corners of semiconductor dies, then the reliability and stress distribution of the package structure is improved, but the device complexity and manufacturing steps increase
Solution Approach 1:
The substrate is segmented by introducing trenches that divide the continuous substrate into distinct regions. These trenches are specifically positioned under the open corners of semiconductor dies to create localized stress management zones, thereby improving package reliability without requiring complete substrate redesign
Solution Approach 2:
The trenches are formed in the substrate before the underfill material is applied. This preliminary action allows the underfill to naturally flow into and fill the trenches during the encapsulation process, pre-positioning stress-relief structures before they are needed to mitigate thermal expansion stresses
2Strength
If underfill material is extended into the substrate through trenches, then tensile stress is better mitigated and cracking risk is reduced, but the manufacturing process complexity increases
Solution Approach 1:
The trenches are formed in the substrate before the underfill material is applied. This preliminary action allows the underfill to naturally flow into and fill the trenches during the encapsulation process, pre-positioning stress-relief structures before they are needed to mitigate thermal expansion stresses
Solution Approach 2:
The underfill material automatically fills the trenches through capillary action during the dispensing process, eliminating the need for separate trench-filling operations. The material self-organizes into the desired configuration based on the trench geometry and dispensing parameters
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
This solution effectively reduces the risk of underfill material cracking and improves the reliability and performance of the package structure by distributing stress more evenly, ensuring better thermal and mechanical stability.
Implementation Method 1
an underfill material over the substrate and including an extension portion
Data Source
AI summary
A package structure is provided. The package structure includes a redistribution structure over a substrate, a semiconductor die over the redistribution structure and electrically coupled to the substrate, and an underfill material over the substrate and encapsulating the redistribution structure and the semiconductor die. The underfill material includes an extension portion overlapping a corner of the semiconductor die and extending into the substrate.