Semiconductor Package Z-Shaped Interconnect for Molding Stress Relief
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Semiconductor packages face reliability issues due to cracks caused by thermal expansion differences between substrates and conductors, leading to reduced product yield and increased costs when using materials with similar thermal expansion coefficients.
Innovation Solution
A semiconductor package design featuring an electrical connecting member with a non-vertical, z-letter shape that disperses or absorbs stress during molding, comprising a first and second substrate with specific metal patterns, and a bent metal piece structure to reduce direct stress on semiconductor chips.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a metal spacer with a vertical structure is directly bonded to the upper insulating substrate, then electrical connection is achieved, but stress concentration occurs during molding causing cracks in bonding members
Solution Approach 1:
The electrical connecting member is designed with a curved z-letter shape instead of a straight vertical structure. This curvature allows the member to flex and absorb stress during the molding process, preventing stress concentration that would otherwise cause cracks in the bonding members while maintaining electrical connectivity between substrates.
Solution Approach 2:
The electrical connecting member changes its physical state by being elastically deformed during molding. The z-letter shape allows controlled flexing that absorbs thermal expansion and molding stresses, transforming the rigid structure into a stress-absorbing component that protects the bonding members from crack formation.
2Reliability
If materials with similar thermal expansion coefficients are used for substrates and conductors, then crack formation is reduced, but manufacturing cost increases significantly
Solution Approach 1:
The patent uses conventional, cost-effective metal materials for the electrical connecting member rather than expensive specialized materials with matched thermal expansion coefficients. The z-letter shape design compensates for the CTE mismatch through geometric flexibility, allowing the use of cheaper materials while maintaining reliability and preventing cracks.
Solution Approach 2:
Instead of changing material composition to match thermal expansion coefficients, the patent changes the geometric parameter of the electrical connecting member to a z-letter shape. This shape transformation allows the structure to accommodate thermal expansion differences through elastic deformation, eliminating the need for expensive matched-material combinations.
3Reliability
If a z-letter shaped electrical connecting member is used, then stress is dispersed during molding, but device structure becomes more complex
Solution Approach 1:
The electrical connecting member adopts a z-letter curved shape that provides stress dispersion capabilities. This curvature allows the member to flex and distribute molding and thermal stresses along its length, protecting the bonding members from concentrated stress while maintaining a relatively simple single-piece construction.
Solution Approach 2:
The z-letter shaped electrical connecting member serves multiple functions: it provides electrical connection between substrates, acts as a spacer to maintain substrate spacing, and functions as a stress-absorbing element during molding and thermal cycling. This multi-functionality reduces the need for additional components, offsetting the increased structural complexity.
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 effectively disperses thermal expansion stress and push stress, preventing cracks in bonding areas and improving semiconductor chip durability while allowing for cost-effective material selection by replacing high-priced metal spacers with copper-based components.
Implementation Method 1
an electrical connecting member having a non-vertical structure bent in a z-letter shape... stress from push and thermal expansion generated while molding by a package housing is dispersed or absorbed
Data Source
AI summary
Provided is a semiconductor package, and more particularly, a semiconductor package in which a semiconductor device is protected in such a way that stress from push and thermal expansion generated while molding by a package housing is dispersed or absorbed through an electrical connecting member having a non-vertical structure bent in a z-letter shape.