Power Semiconductor Module Stepped Housing Corner Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Power semiconductor modules experience production rejects due to unintentional twisting of the substrate relative to the cup-shaped housing, causing contact between the substrate's corners and the housing's corner areas, which is exacerbated by large dimensional tolerances in the substrate production process.
Innovation Solution
The cup rim of the housing is designed with angled extensions in the corner areas, ensuring the substrate's corners remain at a distance from the housing's corners, and the inner edge features elevations with anti-twist knobs to prevent unwanted rotation, thus preventing damage and rejects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the substrate is produced by laser scribing from a multiple substrate with predetermined breaking lines, then manufacturing efficiency is improved, but dimensional tolerances at the outer edge increase causing contact between substrate corners and housing corner areas
Solution Approach 1:
The stepped surface of the cup rim is designed with different geometries in different areas: flat surfaces in the main areas and angled extensions in the corner areas. This local differentiation allows the flat areas to accommodate the substrate's dimensional tolerances while the angled extensions in the corners actively prevent contact between substrate corners and housing corners, thus resolving the contradiction between manufacturing efficiency and precision.
2Stability of the object's composition
If anti-twist knobs are provided on the raised outer rim to prevent substrate twisting, then rotational stability is improved, but contact between substrate corners and housing corner areas cannot be reliably prevented due to dimensional tolerances
Solution Approach 1:
The cup rim's stepped surface incorporates angled extensions specifically in the corner areas, creating a local geometric feature that actively prevents corner contact. This complements the anti-twist knobs by addressing the specific vulnerability of corner areas while maintaining overall rotational stability, thus improving reliability without sacrificing stability.
Solution Approach 2:
The angled extensions are designed in advance to counteract the potential harmful effect of corner contact. By positioning these extensions before assembly, they proactively prevent the substrate corners from reaching the housing corner areas, even when dimensional tolerances cause variations, thus ensuring reliable contact prevention.
3Ease of manufacture
If the substrate corners are allowed to contact the housing corner areas, then assembly simplicity is maintained, but production rejects increase due to substrate twisting and corner contact damage
Solution Approach 1:
The stepped surface with angled extensions in corner areas provides a passive geometric constraint that prevents corner contact without complicating the assembly process. The anti-twist knobs are strategically positioned to guide alignment during assembly. These localized features prevent damage while maintaining overall assembly simplicity, thus avoiding production rejects.
Data Source
Figure 1
Figure 2~4
Figure 5
AI summary
A power semiconductor module (10) comprising a substrate (12) and a cup-shaped housing (14) is described, wherein the circumferential cup rim (16) of the housing (14) is formed with a stepped outer rim (18) and an inner rim (20) recessed relative to it, which are connected to each other by a stepped surface (22). The inner rim (20) can be formed with projections (24) and the outer rim (18) with anti-rotation lugs (26). The substrate (12) rests against the projections (24) with its inner edge regions (30) adjacent to its outer rim (28). The stepped surface (22) is formed in the corner areas (32) of the circumferential cup rim (16) of the housing (14) with a corner-conforming angled extension (34) so that contact between the corners (44) of the substrate (12) and the corner areas (32) of the cup rim (16) is reliably avoided.