Semiconductor Collar Structure to Prevent Thermal Stress Pull-Out
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Semiconductor devices are prone to disengagement from the collar when thermal stress is applied, particularly during temperature cycling tests, due to inadequate resistance and contact area between the case and the base plate.
Innovation Solution
A semiconductor device design featuring a metal or alloy base plate with a first bolt hole, a resin case with a through-hole, and a metal or alloy collar with a second bolt hole and a flange or knurling surface, which enhances the contact area and resistance to disengagement by inhibiting movement of the case away from the base plate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the case and base plate are fastened with a bolt through a collar, then the semiconductor device can be assembled, but the case is likely to disengage from the collar away from the base plate when thermal stress is applied
Solution Approach 1:
The collar is designed with a flange extending in a direction perpendicular to the bolt axis, creating a dimensional constraint that prevents disengagement away from the base plate. This lateral extension of the collar structure adds a new dimension of constraint that addresses the thermal stress disengagement problem without affecting the bolt fastening function.
Solution Approach 2:
The flange of the collar acts as an intermediary element between the case and the base plate, providing additional mechanical support and preventing direct pull-out of the case from the collar. This intermediary structure distributes the thermal stress and prevents disengagement while maintaining the original fastening mechanism.
2Reliability
If the collar has a flange to improve resistance to pull out, then resistance to disengagement improves, but the device complexity increases
Solution Approach 1:
The collar is segmented into functional zones: a fastening portion that interfaces with the bolt and base plate, and a flange portion that prevents disengagement. This segmentation allows each portion to be optimized for its specific function while maintaining overall simplicity. The flange is integrated as a simple extension rather than a separate component.
Solution Approach 2:
The flange is merged with the collar body to form a single integrated component rather than separate parts. This merging reduces assembly steps and overall device complexity while achieving the disengagement prevention function. The collar and flange are manufactured as one piece, eliminating the need for additional fastening or alignment procedures.
Data Source
AI summary
A semiconductor device includes a base plate, a case, and a collar. The base plate includes a metal or an alloy. The base plate has a first bolt hole. The case includes a resin. The case has a first main surface and a second main surface. The second main surface is in contact with the base plate. The case has a through-hole. The collar includes a metal or an alloy. The collar is located within the through-hole. The collar has a first end and a second end. The first end is located on a side where the first main surface is located. The second end is located on a side where the second main surface is located. The collar has a second bolt hole. The first end has a flange. Alternatively, the collar has an outer circumferential surface. The outer circumferential surface has a straight knurling.