Pressure Sintered Cooling Device for Power Converters

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Solution Overview

Problem

Existing power converter arrangements with cooling devices face inefficiencies in heat transfer due to the use of thermally conductive pastes with low thermal conductivity, such as those made from copper and aluminum, which are less effective compared to metal connections.

Innovation Solution

A method involving a metallic molded body cooling device with pressure sintered connections between the power converter circuit substrates and the cooling device, utilizing a metallic material with a low modulus of elasticity like pure aluminum or tempered copper, to create a high thermal conductivity and durable connection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If thermally conductive paste is used to connect power semiconductor module to cooling device, then the connection is easy to manufacture, but the thermal conductivity is low compared to metal connections

Engineering Contradiction:
Improveease of connectionVSAvoidthermal conductivity
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent changes the material parameter from paste to sintered metal, fundamentally altering the thermal conductivity property while maintaining the connection function. The sintering process creates a metal-to-metal bond with thermal conductivity approaching that of solid metal, resolving the contradiction between ease of manufacture and thermal conductivity.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses composite material structure combining sintered metal particles with binder material, creating a connection layer that achieves high thermal conductivity through the metal particle network while maintaining manufacturability through the binder's adhesive properties.

Inventive Principle:
Principle #40Composite materials

2Reliability

If pressure sintering is used to create integral connection between substrate and cooling device, then thermal conductivity and durability are improved, but manufacturing complexity increases

Engineering Contradiction:
Improveconnection durabilityVSAvoidmanufacturing process complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the connection formation process with the existing sintering process used for other components in the power semiconductor module. By integrating the substrate-to-cooling-device connection into the same sintering step, the manufacturing complexity is minimized despite the advanced connection technology.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent introduces a sinterable metal layer as an intermediary between the substrate and cooling device, enabling the pressure sintering process to create durable integral connections. This intermediary layer facilitates the bonding process and ensures reliable thermal and mechanical connection.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of operation

If non-positive connection with screw or clamp is used, then assembly is simple, but heat transfer efficiency is reduced due to contact resistance

Engineering Contradiction:
Improveassembly simplicityVSAvoidheat transfer efficiency
Core Design Contradiction:
Ease of operationVSLoss of energy

Solution Approach 1:

The patent replaces the mechanical screw or clamp connection system with a sintered metal bond, eliminating contact resistance and creating a direct thermal pathway. This substitution maintains assembly simplicity through the sintering process while dramatically improving heat transfer efficiency.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the connection parameter from mechanical contact to metallurgical bond, fundamentally improving thermal contact conductance. The sintered metal connection eliminates the air gaps and contact resistance inherent in mechanical connections, achieving superior heat transfer efficiency.

Inventive Principle:
Principle #35Parameter changes

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 enhances heat transfer efficiency and durability of connections, outperforming traditional soldered connections and thermally conductive pastes by maintaining high thermal conductivity and stability under temperature changes.

Implementation Method 1

Introduction of pressure and temperature to the substrate and the cooling device to form the pressure sintered connection

Methodology Applied
Scientific EffectPressure sintering: Sintering

Implementation Method 2

This creates a material connection that has a high thermal conductivity, that of the sintered metal

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP2271196B1Method for producing a frequency converter with cooling device and frequency converter
Publication Date: 2012.03.14 SEMIKRON DANFOSS ELEKTRONIK GMBH & CO KG
  • EP2271196B1 patent drawingFigure 1~2
  • EP2271196B1 patent drawingFigure 3

AI summary

The method involves providing a print counter piece of the pressure sintering device with a recess for receiving a cooling device (10). The recess is formed as a negative form of cooling device. The cooling device is arranged in the printing counter piece. Substrates (30a,30b) of a converter circuit (20) are arranged on assigned planar sections (16,18) of a main surface (14) of the cooling device. An independent claim is also included for a converter arrangement with conducting paths.