Power Module Corner Press-Fit Anchors Eliminate Screw Fastening
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Solution Overview
Problem
Conventional power semiconductor device modules require additional screws or bolts for mechanical securing, which can cause mechanical stress, warpage, and increased complexity, cost, and delay in installation.
Innovation Solution
Incorporation of novel mechanical corner press-fit anchors that are secured into the housing and extend as press-fit pins, eliminating the need for screws or bolts by providing secure attachment to a PCB during press-fit mounting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If screws or bolts are used to secure the module to the PCB, then mechanical strength is improved, but device complexity and installation time increase
Solution Approach 1:
The patent combines the mechanical anchoring function and electrical connection function into a single integrated press-fit terminal structure. The press-fit terminal includes both a mechanical anchor portion that secures the module to the PCB and an electrical contact portion that provides electrical connection, eliminating the need for separate screws or bolts and reducing device complexity while maintaining mechanical strength.
Solution Approach 2:
The press-fit terminal is designed to perform multiple functions simultaneously: it provides mechanical anchoring through its anchor portion, electrical connection through its contact portion, and stress distribution through its distributed structure. This multi-functional design replaces the need for separate fastening and electrical connection components, reducing installation steps and device complexity.
2Strength
If screws or bolts are used to secure the module to the PCB, then mechanical strength is improved, but installation time and cost increase
Solution Approach 1:
The press-fit terminals are pre-installed and pre-positioned on the module during manufacturing, with their anchor portions extending through the PCB mounting holes. This preliminary action eliminates the need for separate fastening operations during installation, reducing installation time and cost while maintaining the mechanical strength provided by the anchor portions.
Solution Approach 2:
The press-fit terminals are designed to be self-securing through their press-fit mechanism, where the anchor portions are pressed into the PCB mounting holes and automatically secure the module in place without requiring additional fastening operations. This self-service characteristic eliminates the need for separate screw or bolt installation steps, reducing installation time and complexity.
3Strength
If screws or bolts are used to secure the module to the PCB, then mechanical strength is improved, but mechanical stress and warpage increase
Solution Approach 1:
The press-fit terminals are distributed at multiple locations around the module perimeter, with anchor portions positioned at corners and intermediate points. This distributed local arrangement provides localized mechanical anchoring that distributes stress evenly across the module-PCB interface, preventing the concentrated stress and warpage that would result from a single central fastening point.
Solution Approach 2:
The press-fit terminal structure extends in multiple dimensions: the anchor portions extend vertically through the PCB thickness, the intermediate portions provide lateral stress distribution, and the contact portions provide electrical connection. This multi-dimensional structure distributes mechanical stress across different spatial dimensions, reducing localized stress concentration and warpage compared to traditional single-plane screw fastening.
Data Source
AI summary
A power semiconductor device module includes a metal baseplate and a plastic housing that together form a tray. Power electronics are disposed in the tray. A plastic cap covers the tray. Electrical press-fit terminals are disposed along the periphery of the tray. Each electrical terminal has a press-fit pin portion that sticks up through a hole in the cap. In addition, the module includes four mechanical corner press-fit anchors disposed outside the tray. One end of each anchor is embedded into the housing. The other end is an upwardly extending press-fit pin portion. The module is manufactured and sold with the press-fit pin portions of the electrical terminals and the mechanical corner anchors unattached to any printed circuit board (PCB). The mechanical anchors help to secure the module to a printed circuit board. Due to the anchors, screws or bolts are not needed to hold the module to the PCB.