Ultrasonic Welding Device for Power Semiconductor Modules

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional devices for welding connections between connection elements and conductor tracks in power semiconductor modules often damage the insulating body, leading to detachment and reduced durability due to excessive energy introduction during the welding process.

Innovation Solution

A device featuring a dual-abutment system with a metallic and an elastic partial abutment, a holding device, and a positioning system that uses a sonotrode for ultrasonic welding, where the elastic abutment with a modulus of elasticity between 10 and 500 N/mm² dampens the welding process, preventing damage to the substrate.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a welding connection is executed using a standard welding device, then the connection element can be welded to the conductor track, but the energy applied to the connection element can pre-damage or damage the connection between the metal layer and the insulating material

Engineering Contradiction:
Improveconnection qualityVSAvoiddamage to substrate
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent introduces an elastic abutment as an intermediary element between the rigid support structure and the substrate. This elastic abutment absorbs and dampens the welding energy, preventing direct transmission of harmful force peaks to the substrate while still enabling effective welding of the connection element to the conductor track.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the mechanical parameters of the support system by introducing an elastic abutment with specific elastic modulus, thereby modifying how welding energy is transmitted. This parameter change allows the system to filter out harmful high-frequency vibrations and force peaks while maintaining the necessary welding pressure and energy transfer.

Inventive Principle:
Principle #35Parameter changes

2Strength

If high energy is applied during welding to ensure strong connection, then welding strength is improved, but the connection between metal layer and insulating material can detach

Engineering Contradiction:
Improvewelding strengthVSAvoidintegrity of substrate connection
Core Design Contradiction:
StrengthVSStability of the object's composition

Solution Approach 1:

The elastic abutment serves as a mediator that decouples the high-energy welding process from the sensitive substrate structure. It allows strong welding connections to be formed while filtering out the damaging components of the welding energy that would otherwise cause detachment of the metal layer from the insulating material.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The elastic abutment provides beforehand cushioning by being positioned between the welding apparatus and the substrate. It is designed to absorb and dampen welding energy in advance, preventing the transmission of harmful force peaks before they can damage the substrate connections.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

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 solution ensures a gentler welding process, improving connection quality and preventing damage to the substrate, thereby enhancing the durability and reliability of power semiconductor modules by reducing force peaks and maintaining the integrity of the connection between the conductor tracks and the insulating body.

Implementation Method 1

a sonotrode; a positioning device for positioning the connecting element to the substrate such that a contact foot of the connecting element rests on a contact point of a conductor track of the substrate and is connected to it by means of the sonotrode

Methodology Applied
Scientific EffectUltrasonic welding: Ultrasonic Vibration

Implementation Method 2

the second partial support is an elastic shaped body with a modulus of elasticity between 10 and 500 N/mm2 and wherein the base element rests on the second partial support

Methodology Applied
Scientific EffectElastic damping: Elasticity

Data Source

PatentEP2927940B1Device for welding together connection elements with the substrate of a power semiconductor module and associated method
Publication Date: 2019.08.21 SEMIKRON DANFOSS ELEKTRONIK GMBH & CO KG
  • EP2927940B1 patent drawingFigure 1
  • EP2927940B1 patent drawingFigure 2
  • EP2927940B1 patent drawingFigure 3~4

AI summary

A device for welding a terminal element of a power semiconductor module to a conductor track is presented, comprising: a support for the substrate, the support having a first and a second partial support, the first partial support being a metallic form with a modulus of elasticity between 50 and 300 kN/mm² and the second partial support being an elastic form with a modulus of elasticity between 10 and 500 N/mm², and the base element resting on the second partial support; a holding device configured to fix the base element to the support; a sonotrode; and a positioning device for positioning the terminal element relative to the substrate. A manufacturing process for a power semiconductor module using the device is also presented.