Embedded Flexible Signal Connector for 3D Power Module Assembly

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Solution Overview

Problem

Existing power semiconductor modules face high costs and complex manufacturing processes due to the need for multiple signal connections, which are often realized through stamped metal terminals or printed circuit boards, leading to increased tooling and assembly efforts.

Innovation Solution

The use of a mechanically flexible internal electrical signal connector that can be pre-fabricated and configured in three dimensions, allowing for adjustable placement and embedding within the module's sealing material, reducing the need for complex manufacturing and providing flexible interconnections.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If terminals made of stamped and bent metal sheets are used for signal connections, then electrical connectivity is achieved, but manufacturing costs and tooling efforts increase due to individual stamping and bending processes for multiple terminals

Engineering Contradiction:
Improveelectrical connectivityVSAvoidmanufacturing costs
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

Multiple separate metal sheet terminals are merged into a single flexible printed circuit board that provides all necessary signal connections. The FPC integrates multiple signal traces, power supply lines, and ground connections in one continuous flexible substrate, eliminating the need for individual stamping and bending processes for each terminal.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The flexible printed circuit board serves multiple functions simultaneously: it provides signal transmission, power supply, ground reference, and mechanical support. This single multi-functional component replaces what would otherwise require multiple separate metal terminals and associated manufacturing processes.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Ease of manufacture

If a printed circuit board is used for electrically connecting power module substrates, then material costs may be lower, but manufacturing and assembly complexity increases due to complicated connection processes and wire-bond preparation

Engineering Contradiction:
Improvematerial costsVSAvoidmanufacturing process complexity
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The rigid printed circuit board is replaced with a flexible printed circuit board that can be bent and shaped to accommodate the three-dimensional arrangement of power semiconductor devices. This flexibility simplifies the assembly process by allowing direct routing to device terminals without requiring complex wire-bond preparation or rigid board positioning.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

A flexible printed circuit board made from thin flexible substrate material is used instead of a rigid PCB. The flexible nature of this thin film allows it to conform to the module's internal geometry and be easily integrated during assembly, reducing manufacturing complexity while maintaining low material costs.

Inventive Principle:
Principle #30Flexible shells and thin films

3Adaptability or versatility

If multiple terminals with different designs are manufactured by individual stamping and bending processes, then customized signal connections are achieved, but tooling and manufacturing efforts increase

Engineering Contradiction:
Improvesignal connection customizationVSAvoidtooling and manufacturing efforts
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The flexible printed circuit board is segmented into multiple functional regions with different trace patterns, impedance characteristics, and connection types. This allows customization of signal connections for different applications while manufacturing all segments in a single continuous process, eliminating the need for multiple tooling setups.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP4485522B1Power semiconductor module comprising embedded flexible electrical signal connector and method for producing a power semiconductor module
Publication Date: 2025.10.15 HITACHI ENERGY LTD
  • EP4485522B1 patent drawingFigure 1A~1B
  • EP4485522B1 patent drawingFigure 2~3
  • EP4485522B1 patent drawingFigure 4~5

AI summary

A power semiconductor module (100) is provided which comprises a first module part (1, 1A, 1B), a second module part (2, 2A, 2B), an internal electrical signal connector (12) and a sealing material (3). The internal electrical signal connector (12) is mechanically flexible and electrically connects at least one of the first module part (1, 1A, 1B) and the second module part (2, 2A, 2B) with at least one signal conductor (12A, 12B) of the internal electrical signal connector (12). The internal electrical signal connector (12) is at least partly embedded within the sealing material (3). Due to its mechanical flexibility, the internal electrical signal connector (12) is configurable in three dimensions in the absence of the sealing material (3) and is located at pre-designed position in three dimensions in the power semiconductor module (100). Furthermore, a method for producing a power semiconductor module (100) is provided.