Semiconductor Package Pad Layout for Under Bump Stress Relief
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The concentration of tensile stress at the corners of under bump metallurgy structures in semiconductor package structures leads to cracking of insulating layers, compromising the performance and reliability of the package structure.
Innovation Solution
The conductive pad of the conductive line is designed to entirely cover the corner of the under bump metallurgy structure, mitigating the tensile stress and reducing the risk of cracking in the insulating layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the under bump metallurgy structure is used to connect conductive pads, then electrical connection is achieved, but tensile stress concentrates at the corners causing insulating layer cracking
Solution Approach 1:
The conductive pad is designed with extended corners that locally cover the corners of the under bump metallurgy structure. This local extension specifically addresses the stress concentration problem at the corners without changing the overall structure, distributing the tensile stress away from the insulating layer corners and preventing cracking while maintaining electrical connection reliability.
2Productivity
If smaller package structures are developed to reduce area and height, then production efficiency increases and costs decrease, but manufacturing challenges arise for new packaging technologies
Solution Approach 1:
The conductive pad is segmented into multiple regions including corner extensions that specifically cover the corners of the under bump metallurgy structure. This segmentation allows different parts of the pad to serve different functions: the corner extensions provide stress distribution and cracking prevention, while the central region maintains electrical connection, thereby facilitating manufacturing of smaller packages without compromising reliability.
Data Source
AI summary
A package structure is provided. The package structure includes a first conductive pad in a first insulating layer, a conductive via in a second insulating layer directly under the first conductive pad, and a first under bump metallurgy structure directly under the first conductive via. In a first horizontal direction, the conductive via is narrower than the first under bump metallurgy structure, and the first under bump metallurgy structure is narrower than the first conductive pad.