Power Semiconductor Module Hard Encapsulation for Mechanical Robustness
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Solution Overview
Problem
Power semiconductor modules face mechanical robustness issues due to misalignment and high forces exerted on contact elements during mounting, leading to potential damage over time, especially in larger modules with greater distances between contact elements.
Innovation Solution
A power semiconductor module arrangement with a hard encapsulation that fills the housing and surrounds the substrate and contact elements, providing mechanical stability and protection against lateral thermal cycles, using a material with a hardness of at least 40 Shore A and including a filler for enhanced stability and corrosion resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If contact elements are mounted on the substrate and protrude through the housing cover, then electrical connection and mechanical coupling to the printed circuit board are enabled, but misalignment and high forces during mounting lead to mechanical damage over time
Solution Approach 1:
The patent applies beforehand cushioning by introducing a damping element between the contact element and the housing cover. This damping element absorbs and distributes the mechanical forces that occur during mounting and operation, preventing direct transmission of high forces to the contact element. The cushioning effect is established in advance before any damage can occur, thereby protecting the contact element from misalignment-related stress and extending its durability while maintaining reliable electrical connection.
2Stability of the object's composition
If the housing is left empty or with minimal encapsulation, then manufacturing simplicity is maintained, but mechanical stability and protection against thermal cycles are insufficient
Solution Approach 1:
The patent applies parameter changes by modifying the physical state and properties of the encapsulation material. The material is introduced in a moldable state that allows it to conform to the housing cavity and surrounding components, then undergoes a phase change or curing process to achieve the desired hardness and mechanical stability. This parameter transformation enables the encapsulation material to provide robust mechanical support and thermal cycle protection while maintaining relatively simple manufacturing procedures.
3Strength
If hard encapsulation material is used to protect contact elements, then mechanical robustness is enhanced, but the material must be moldable enough to conform to complex housing geometries
Solution Approach 1:
The patent resolves this contradiction by utilizing parameter changes in the encapsulation material's physical state. The material is supplied in a soft, moldable state that allows it to be easily injected or placed into the housing cavity and conform to complex geometries. After molding, the material undergoes a transformation (curing, hardening, or phase change) to achieve the required hardness and protective properties. This temporal separation of moldability and hardness enables both easy manufacturing and effective protection.
4Object-affected harmful factors
If the encapsulation material is too soft, then ease of application is maintained, but protection against corrosive gases and mechanical damage is insufficient
Solution Approach 1:
The patent applies parameter changes by using an encapsulation material that transitions from a soft, easily applicable state to a hard, protective state. In its initial form, the material is sufficiently soft to be easily molded or injected into the housing cavity. After application, through curing or hardening processes, it transforms into a dense, corrosion-resistant barrier that effectively protects the contact elements and substrate from harmful environmental factors while maintaining manufacturing ease.
Data Source
AI summary
A method is disclosed for producing a power semiconductor module that includes a substrate, at least one semiconductor body, a connecting element and a contact element. The method includes: arranging the substrate in a housing having walls; at least partly filling a capacity formed by the walls of the housing and the substrate with an encapsulation material; hardening the encapsulation material to form a hard encapsulation; and closing the housing, wherein the contact element extends from the connecting element through an interior of the housing and through an opening in a cover of the housing to an outside of the housing in a direction perpendicular to a first surface of a first metallization layer of the substrate.