Power Semiconductor Module Dual-Layer Encapsulation
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Solution Overview
Problem
Existing power semiconductor modules face challenges in achieving long-term reliability due to inadequate protection against mechanical and environmental influences, particularly humidity, which can lead to reliability issues in applications like subsea environments.
Innovation Solution
A power semiconductor module design that combines a sealing material, such as epoxy moulding compounds, with a protecting material like silicone gel, providing comprehensive protection and improved creepage distances, mechanical stability, and insulation properties, while allowing for flexible design and easy production.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If only sealing material is used to protect power semiconductor devices, then the structure is simple and easy to manufacture, but the protection against mechanical and environmental influences is insufficient
Solution Approach 1:
The patent applies composite materials by combining sealing material and protecting material into a unified encapsulation structure. The sealing material provides primary sealing and mechanical support, while the protecting material adds enhanced protection against environmental factors such as humidity and chemicals. This composite approach resolves the contradiction by achieving superior reliability through material combination while maintaining manufacturing simplicity through a integrated application process.
Solution Approach 2:
The patent implements the nesting principle by placing the protecting material inside the sealing material structure. The protecting material is positioned within the encapsulation formed by the sealing material, creating a nested configuration where the inner protecting material provides specialized protection while the outer sealing material provides structural integrity and primary sealing. This nested arrangement enhances protection capabilities without significantly increasing structural complexity.
2Reliability
If protective coatings are applied to all components, then protection is comprehensive, but the manufacturing process becomes more complex and time-consuming
Solution Approach 1:
The patent merges the application of sealing material and protecting material into a single integrated manufacturing step. Rather than applying separate coatings to different components at different times, both materials are applied together in a combined encapsulation process that simultaneously provides comprehensive protection. This merging approach achieves complete protection coverage while simplifying the manufacturing process and reducing production time.
3Reliability
If a single encapsulation material is used, then the manufacturing process is simple, but the creepage distance and insulation properties are insufficient
Solution Approach 1:
The patent applies local quality by assigning different functional properties to different material layers. The sealing material is formulated with properties optimized for mechanical strength and primary sealing, while the protecting material is formulated with properties optimized for electrical insulation and creepage distance enhancement. This local differentiation of material qualities achieves superior electrical and insulation performance while maintaining a relatively simple two-layer structure that is easy to manufacture.
Data Source
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AI summary
The present invention provides a power semiconductor module (10), comprising a support (12) which carries at least one power semiconductor device (14), wherein the support (12) together with the power semiconductor device (14) is at least partly located in a housing (20), wherein the support (12) and the power semiconductor device (14) are at least partly covered by a sealing material (22), characterized in that additionally to the sealing material (22), a protecting material (24) is provided in the housing (20), wherein the protecting material (24) is formed from silicon gel and wherein the protecting material (24) at least partly covers at least one of the support (12), the power semiconductor device (14) and the sealing material (22).