Lead Electrode Intervening Structure to Suppress Semiconductor Cracks
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Semiconductor devices experience cracks due to thermal stress from cold-hot cycles, leading to reduced reliability despite existing techniques to mitigate stress through material and shape modifications of lead electrode terminals.
Innovation Solution
Incorporating an intervening member between the end portion of the lead electrode terminal and the semiconductor element, with a sealing resin interface, to change the crack development direction and suppress crack propagation to the semiconductor element.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If material selection and shape design of lead electrode terminal are optimized to reduce thermal expansion stress, then stress in sealing resin is reduced, but cracks still propagate to semiconductor element when temperature difference is large
Solution Approach 1:
A stress relief structure is introduced as an intermediary element between the lead electrode terminal and the sealing resin. This stress relief structure includes a relief portion that protrudes from the lower surface of the lead electrode terminal, creating a stepped configuration that interrupts stress transmission paths and prevents crack propagation to the semiconductor element.
Solution Approach 2:
The lead electrode terminal is segmented into different levels by introducing a relief portion that protrudes from its lower surface. This segmentation creates distinct stress zones, with the relief portion acting as a stress break point that divides the continuous stress path into separate segments, thereby preventing crack propagation.
2Stress or pressure
If lead electrode terminal is designed with special shape to reduce sealing resin stress, then thermal expansion stress is mitigated, but device complexity increases
Solution Approach 1:
Instead of changing the overall shape of the lead electrode terminal, the invention applies a localized relief portion only at the lower surface near the semiconductor element. This local modification creates stress relief where needed without affecting the upper portions of the terminal that connect to external circuits, thereby minimizing increased device complexity.
Solution Approach 2:
Conventionally, stress relief features are added to the upper portions of lead electrodes. This invention inverts the approach by placing the relief portion at the lower surface near the semiconductor element, where stress concentration and crack initiation are most critical, thereby achieving stress relief with minimal impact on overall device structure.
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 suppresses cracks reaching the semiconductor element, enhancing the reliability of semiconductor devices by altering the crack development direction and distributing thermal stress effectively.
Implementation Method 1
distributing thermal stress effectively
Implementation Method 2
a stress occurs in the sealing resin due to a difference in linear expansion coefficient between the lead electrode terminal and the sealing resin
Data Source
AI summary
An object is to provide a technique capable of suppressing a crack that reaches a semiconductor element. A semiconductor device includes a semiconductor element, a lead electrode terminal, a first sealing member, and an intervening member. The lead electrode terminal has an extending portion separated from an upper surface of the semiconductor element, and is bonded to the semiconductor element. The first sealing member seals the lead electrode terminal. The intervening member is provided between an end portion of the extending portion in an extending direction and the semiconductor element. The intervening member has an interface with the first sealing member under the end portion.