Semiconductor Housing Package Lead Member Bends for Thermal Stress
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Solution Overview
Problem
Existing semiconductor element housing packages face challenges in suppressing cracks and fractures due to heat generation from power semiconductor elements, which affects the reliability and durability of the packaging.
Innovation Solution
A semiconductor element housing package design featuring a substrate with a ceramic frame body and insulating substrate, along with strategically positioned lead members and mounting members, which includes a first and second lead member with bends to facilitate efficient heat dissipation and reduce thermal stress, thereby minimizing the occurrence of cracks and fractures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a power semiconductor element is mounted on a lead member in a conventional housing package, then the device can be manufactured with simple structure, but cracks and fractures occur due to thermal expansion stress from heat generation
Solution Approach 1:
The lead member is divided into multiple sections with different bend radii (first bend portion with larger radius, second bend portion with smaller radius). This segmentation allows different parts of the lead member to handle thermal expansion stress differently, with the smaller radius bend absorbing more stress while the larger radius bend provides structural stability.
Solution Approach 2:
The lead member's geometry is changed by introducing bends with specific radius ratios (smaller radius to larger radius between 0.3-0.7). This parameter change in the lead member's shape allows it to flex and absorb thermal expansion stress while maintaining electrical connectivity, preventing cracks and fractures.
2Strength
If the lead member is made rigid to maintain structural stability, then mechanical strength is improved, but thermal expansion stress causes cracks and fractures
Solution Approach 1:
The lead member is designed with dynamic flexibility through bends of different radii. The smaller radius bend portion can flex and deform to accommodate thermal expansion, while the larger radius bend maintains overall structural stability. This dynamic design allows the lead member to adapt to thermal stress without fracturing.
Solution Approach 2:
The lead member incorporates bend portions that act as pre-designed stress absorption zones. These bends are positioned beforehand to cushion and distribute thermal expansion stress, preventing it from concentrating at critical points where cracks would initiate.
3Reliability
If the lead member is made flexible to absorb thermal stress, then resistance to cracks is improved, but structural stability and mechanical strength decrease
Solution Approach 1:
The lead member is segmented into rigid portions and flexible bend portions with different radius characteristics. The smaller radius bends provide flexibility for stress absorption, while the larger radius bends and straight portions maintain structural integrity and mechanical strength.
Solution Approach 2:
Different portions of the lead member have different local qualities - the smaller radius bend portions are designed for flexibility and stress absorption, while the larger radius bend portions maintain structural stability. This local differentiation allows the lead member to simultaneously achieve both flexibility and strength.
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 suppresses thermal expansion and stress, enhancing the hermeticity and heat-dissipation capabilities of the semiconductor element housing package, reducing the likelihood of cracks and fractures, and ensuring reliable operation under high-temperature conditions.
Implementation Method 1
suppressing occurrence of cracks and fracture due to generation of heat from a power semiconductor element
Implementation Method 2
a first lead member having a first bend and a second lead member having a second bend
Data Source
AI summary
A semiconductor element housing package includes a substrate, a frame body disposed on the substrate; an insulating substrate disposed in a frame-body-surrounded region of the substrate; a first mounting member disposed on the insulating substrate, for mounting a power semiconductor element thereon; a second mounting member disposed on the insulating substrate so as to be spaced away from the first mounting member; a first lead member having a first bend; and a second lead member having a second bend. The first lead member is disposed so as to pass through the frame body from an exterior thereof and extend over the first mounting member and makes connection therewith through the first bend. The second lead member is disposed so as to pass through the frame body from the exterior thereof and extend over the second mounting member and makes connection therewith through the second bend.