Annular-Groove Heat Dissipation Substrate for Reflow Warpage
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Power modules experience warpage during reflow due to differing thermal expansion coefficients of materials, affecting structural reliability.
Innovation Solution
A heat dissipation structure with an annular groove on the substrate, dividing it into a configuration and periphery area, and optionally including auxiliary grooves, to release stress and reduce warpage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the heat dissipation substrate is connected with the DBC chip circuit board, then the power module achieves proper thermal management and electrical connection, but warpage occurs during reflow due to different thermal expansion coefficients of materials
Solution Approach 1:
The substrate is segmented by the annular groove into a configuration area and a periphery area, allowing differential thermal expansion in different regions. This segmentation enables the structure to accommodate thermal stress without warping during reflow processing.
Solution Approach 2:
The annular groove creates local quality differences between the configuration area and periphery area, where the periphery area has enhanced stress relief capability. This local modification allows the substrate to handle thermal expansion differences while maintaining overall structural integrity.
2Shape
If the annular groove is made deeper to better release stress, then warpage reduction improves, but the structural strength of the substrate decreases
Solution Approach 1:
The annular groove depth is set to less than or equal to half the substrate thickness, providing sufficient stress relief for warpage prevention while maintaining adequate structural strength. This partial action approach avoids over-cutting the substrate.
Solution Approach 2:
The depth of the annular groove is optimized as a critical parameter, set between 5% and 50% of the substrate thickness. This parameter optimization balances stress relief capability with structural strength requirements.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The heat dissipation structure effectively reduces warpage during reflow, enhancing the structural reliability of power modules.
Implementation Method 1
the stress generated by the substrate during reflow may be released
Implementation Method 2
multiple heat dissipation fins separately configured on the lower surface of the substrate
Implementation Method 3
multiple heat dissipation fins separately configured on the lower surface of the substrate
Data Source
AI summary
A heat dissipation structure includes a substrate and an annular groove. The substrate has an upper surface and a lower surface opposite to each other. The annular groove is configured on the upper surface of the substrate to divide the substrate into a configuration area and a periphery area. The annular groove is located between the configuration area and the periphery area. A depth of the annular groove is less than or equal to half of a thickness of the substrate.