Terminal Element Geometry for Thermo-Mechanical Stress Relief

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Solution Overview

Problem

Power semiconductor module arrangements face a significant challenge due to thermo-mechanical stress, which can damage or destroy the connections between terminal elements and substrates, leading to reduced module lifetime.

Innovation Solution

A terminal element design featuring a first section with a smaller width, a second section with a greater width angled relative to the first section, and a third section providing additional stability, helps to distribute thermo-mechanical stress and enhance the connection area with the substrate.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If terminal elements are soldered, sintered or welded to the substrate to form stable mechanical and electrical connection, then the electrical connection between terminal elements and substrate is improved, but the connections may be damaged or destroyed due to thermo-mechanical stress during operation, reducing the lifetime of the power semiconductor module arrangement

Engineering Contradiction:
Improveelectrical connection stabilityVSAvoidmodule lifetime
Core Design Contradiction:
ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The terminal element is divided into multiple sections (first section, second section, third section) with different widths and orientations. This segmentation allows each section to handle stress differently, with wider sections providing stability and narrower sections providing flexibility, thereby resolving the contradiction between maintaining strong electrical connection and withstanding thermo-mechanical stress over the module's lifetime

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different sections of the terminal element have different local properties: the first section has a smaller width for flexibility, the second section has a greater width for stress distribution, and the third section has a different orientation for additional stability. This local differentiation allows the terminal element to simultaneously achieve strong electrical connection and resistance to thermo-mechanical stress

Inventive Principle:
Principle #3Local quality

2Ease of manufacture

If terminal elements are made with uniform width for simplicity, then the manufacturing process is easier, but the terminal elements are more susceptible to delamination under thermo-mechanical stress

Engineering Contradiction:
Improveterminal element fabricationVSAvoidconnection stability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The terminal element is segmented into sections with different widths rather than using a uniform width design. This segmentation, while slightly increasing manufacturing complexity, dramatically improves connection stability by distributing thermo-mechanical stress across sections of varying widths, preventing delamination during operation

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP4510184A1Terminal element, and power semiconductor module arrangement comprising a terminal element
Publication Date: 2025.02.19 INFINEON TECHNOLOGIES AG
  • EP4510184A1 patent drawingFigure 1~3
  • EP4510184A1 patent drawingFigure 4~5
  • EP4510184A1 patent drawingFigure 6

AI summary

A terminal element for a power semiconductor module arrangement comprises a first end (41) configured to be arranged inside a housing (7) of the power semiconductor module arrangement (100), a second end (42) configured to be arranged outside of the housing (7) of the power semiconductor module arrangement (100), a first section (410) and a second section (420) arranged successively between the first end (41) and the second end (42) along a length (l4) of the terminal element (4), and a third section (430) arranged between the first section (410) and the second section (420), wherein the first section (410) has a first width (w410), the second section (420) extends in a first direction (z) and has a second width (w420) that is greater than the first width (w410), and the third section (430) has a width greater than the first width (w410), and extends in a second direction (y) which is angled relative to the first direction (z).