Power Semiconductor Module Assembly With Variable-Height Spacers
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Solution Overview
Problem
Power semiconductor module arrangements face issues due to thermal expansion differences between substrates, connection layers, and base plates, leading to deformation and uneven connection layers, which affect performance and reliability.
Innovation Solution
Incorporating spacers of varying heights between substrates and the base plate, with specific configurations of first and second kind spacers, to maintain a uniform connection layer thickness and prevent deformation during the assembly process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If base plate is pre-bent to have convex deflection to compensate for thermal deformation, then base plate flatness after assembly is improved, but connection layer uniformity deteriorates
Solution Approach 1:
The patent applies local quality by using spacers of different heights (first kind with height H1 and second kind with height H2) at different locations on the base plate. This localized variation in spacer height compensates for the non-uniform thermal deformation of the pre-bent base plate, ensuring uniform connection layer thickness in different regions despite the base plate's initial convex deflection.
Solution Approach 2:
The patent applies preliminary action by pre-bending the base plate to have a convex deflection before assembling the substrates and connection layers. This pre-applied deformation anticipates and compensates for the concave deflection that will occur during thermal processing, so that the base plate becomes essentially flat after heating and cooling, thereby maintaining connection layer uniformity.
2Manufacturing precision
If spacers of different heights are used to maintain connection layer uniformity, then connection layer thickness uniformity is improved, but device complexity increases
Solution Approach 1:
The patent uses spacers of different heights at different locations to compensate for non-uniform base plate deformation. The first kind of spacers (height H1) are placed in regions requiring less compensation, while the second kind of spacers (height H2) are placed in regions requiring greater compensation, achieving uniform connection layer thickness through localized adaptation.
Solution Approach 2:
The patent segments the spacer system into two distinct types (first kind and second kind) with different heights, allowing independent optimization for different regions of the base plate. This segmentation enables precise control of connection layer thickness in various areas without requiring a completely customized spacer for each location.
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
This approach ensures a more reliable and efficient power semiconductor module arrangement by maintaining uniform connection layer thickness, reducing deformation, and enhancing overall performance.
Implementation Method 1
heating the base plate with the plurality of substrates and connection layers arranged thereon, thereby liquefying the material of the plurality of connection layers
Implementation Method 2
cooling the base plate with the plurality of substrates and connection layers arranged thereon, thereby solidifying the material of the plurality of connection layers
Implementation Method 3
When heating, and subsequently cooling the different components during the assembly process, the difference between the CTEs (coefficients of thermal expansion) of the different materials leads to a deformation of the base plate
Data Source
Figure 1~2B
Figure 2C~4B
Figure 4C~6
AI summary
A power semiconductor module arrangement comprises a base plate (80), a plurality of substrates (10) arranged on a first surface of the base plate (80), a plurality of connection layers (62), wherein each of the plurality of connection layers (62) is arranged between a different one of the plurality of substrates (10) and the base plate (80) and permanently attaches the respective substrate (10) to the base plate (80), and a plurality of spacers (82, 822, 824), wherein each of the plurality of spacers (82) is arranged between one of the plurality of substrates (10) and the base plate (80), and is embedded in the material of the respective connection layer (62), wherein for at least one of the plurality of substrates (10) the following applies: either no spacer (82, 822, 824) or one or more of a first kind of spacers (822) having a first height (h1) in a vertical direction (y) perpendicular to the first surface of the base plate (80) is arranged below a first half of the respective substrate (10), and one or more of a second kind of spacers (824) having a second height (h2) in the vertical direction (y) is arranged below a second half of the respective substrate (10), wherein the second height (h2) is greater than the first height (h1).