Vertical Contact Elements for Low Inductance in Power Modules

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Solution Overview

Problem

Power semiconductor module arrangements face challenges in achieving increased symmetry and low inductance, which are crucial for many applications but often not adequately addressed by existing designs.

Innovation Solution

The design incorporates contact elements with a first and second electrically conducting part separated by an electrically insulating layer, extending vertically from a metallization layer on a semiconductor substrate, allowing for increased symmetry and low inductance by preventing electrical connection between the parts while maintaining mechanical and electrical connectivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If contact elements are arranged on the substrate and protrude perpendicular to the main surface, then mechanical and electrical connection to the printed circuit board is achieved, but symmetry of the semiconductor arrangement is reduced

Engineering Contradiction:
Improvemechanical and electrical connectionVSAvoidsymmetry
Core Design Contradiction:
Ease of operationVSShape

Solution Approach 1:

The contact elements are extended in the vertical direction perpendicular to the substrate surface, creating a three-dimensional arrangement that projects contact points onto the printed circuit board in a symmetric pattern. This dimensional extension allows the contact elements to maintain symmetry in the horizontal plane while achieving mechanical connection in the vertical dimension.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Reliability

If contact elements are arranged on the substrate, then electrical connection is achieved, but inductance increases

Engineering Contradiction:
Improveelectrical connectionVSAvoidinductance
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

Each contact element is divided into multiple electrically isolated conducting parts separated by insulating layers. This segmentation creates multiple parallel electrical paths from the substrate to the printed circuit board, reducing the overall inductance while maintaining reliable electrical connection. The insulating layers prevent electrical breakdown between segments.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The contact elements are constructed as composite structures combining electrically conducting parts with electrically insulating layers. This composite design allows the conducting parts to provide multiple parallel current paths for low inductance, while the insulating parts prevent electrical breakdown and maintain structural integrity.

Inventive Principle:
Principle #40Composite materials

3Object-affected harmful factors

If contact elements have large length in vertical direction compared to horizontal dimensions, then low inductance is achieved, but mechanical strength may be reduced

Engineering Contradiction:
ImproveinductanceVSAvoidmechanical strength
Core Design Contradiction:
Object-affected harmful factorsVSStrength

Solution Approach 1:

The contact elements are segmented into multiple shorter conducting parts rather than one long continuous conductor. This segmentation reduces the inductance of each segment while the collective arrangement maintains the required electrical connection. The insulating layers between segments provide mechanical support.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Electrically insulating layers are introduced as intermediary structures between the conducting parts. These insulating layers provide mechanical support and structural stability to the elongated contact elements, preventing buckling or deformation while allowing the conducting parts to maintain their low-inductance geometry.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP3644358B1Power semiconductor module arrangement including a contact element
Publication Date: 2021.10.13 INFINEON TECHNOLOGIES AG
  • EP3644358B1 patent drawingFigure 1~2
  • EP3644358B1 patent drawingFigure 3A~5
  • EP3644358B1 patent drawingFigure 6~7

AI summary

A power semiconductor module arrangement comprises a semiconductor substrate (10) comprising a dielectric insulation layer (11), and a first metallization layer (111) arranged on a first side of the dielectric insulation layer (11), at least one semiconductor body (20) mounted on a first surface (101) of the first metallization layer (111) which faces away from the dielectric insulation layer (11), and at least one contact element (22) that is mechanically and electrically connected to the first metallization layer (111), wherein each of the contact elements (22) extends from the first metallization layer (111) in a vertical direction (y) perpendicular to the first surface (101). Each contact element (22) comprises a first electrically conducting part (221), a second electrically conducting part (222), and an electrically insulating layer (23) arranged between the first part (221) and the second part (222), thereby interconnecting the first part (221) and the second part (222) and preventing an electrical connection between the first part (221) and the second part (222). Each contact element (22) has a first length (li) in the vertical direction (y) that is large as compared to its dimensions (bn, wn) in a first and second horizontal direction (x, z) perpendicular to the vertical direction (y). The electrically insulating layer (23) of a contact element (22) extends between the respective first part (221) and second part (222) in the vertical direction (y).