Bare Die Power Semiconductor Module Direct Coolant Cooling

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Power semiconductor modules in motor vehicles face inefficiencies in cooling due to complex heat transfer paths and the need for tight seals, which complicates the use of cooling liquids and reduces thermal coupling effectiveness.

Innovation Solution

The power semiconductor chips are designed as bare dies without a housing, allowing direct cooling by an electrically insulating liquid, eliminating additional heat transfer paths and the need for complex seals and heat sinks, with a carrier element providing a path for coolant flow around the chips.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If power semiconductor chips are arranged on a heat sink with cooling channels, then cooling capability is improved, but device complexity increases due to seals and heat transfer paths

Engineering Contradiction:
Improvecooling capabilityVSAvoidseals and heat transfer paths
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The invention extracts the housing from the power semiconductor chip, transforming it from a packaged component to a bare die. This eliminates the need for complex seals and heat transfer paths between the chip housing and heat sink, while maintaining effective cooling through direct thermal contact with the carrier element

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention merges the chip housing function with the carrier element by directly mounting the bare die onto the carrier element's heat dissipation surface. This integration eliminates intermediate heat transfer components and creates a unified thermal management structure

Inventive Principle:
Principle #5Merging (Combining)

2Reliability

If complex seals and heat transfer means are used, then tightness and thermal coupling are improved, but manufacturing effort increases

Engineering Contradiction:
Improvetightness and thermal couplingVSAvoidmanufacturing effort
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

By removing the chip housing and using bare dies directly mounted on the carrier element, the invention eliminates multiple assembly steps involving seals, thermal paste, and precision alignment procedures, significantly reducing manufacturing complexity while maintaining reliable thermal coupling

Inventive Principle:
Principle #2Taking out (Extraction)

3Reliability

If a long heat transfer path is used from chip to heat sink, then chip protection is improved, but heat dissipation efficiency decreases

Engineering Contradiction:
Improvechip protectionVSAvoidheat dissipation efficiency
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The invention removes the chip housing that creates a long heat transfer path, allowing the bare die to be in direct thermal contact with the carrier element's heat dissipation surface. This dramatically shortens the thermal path and improves heat dissipation efficiency

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

Instead of protecting the chip through a housing that thermally isolates it, the invention inverts the approach by using the carrier element itself as both the mounting substrate and heat sink, creating direct thermal contact while providing mechanical support and protection

Inventive Principle:
Principle #13The other way round (Inversion)

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 enables efficient and simplified cooling of power semiconductor chips, reducing manufacturing effort and enhancing heat dissipation directly on the chip surface, while maintaining electrical insulation and thermal management.

Implementation Method 1

a cooling liquid introduced through a cooling liquid supply line into the power semiconductor module flows directly around them

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

A cooling liquid flows through the cooling channels and, because of the thermal coupling of the heat sink to the power semiconductor chips, dissipates the heat from them

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 3

an electrically insulating liquid, eliminating additional heat transfer paths and the need for complex seals and heat sinks

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP3401956B1Power semiconductor module for a motor vehicle and motor vehicle
Publication Date: 2020.05.27 AUDI AG
  • EP3401956B1 patent drawingFigure 1~2
  • EP3401956B1 patent drawingFigure 3

AI summary

Power semiconductor module for a motor vehicle, wherein several unpackaged power semiconductor chips (6) are provided which are arranged to be directly surrounded by a coolant (8) introduced into the power semiconductor module (1) by a coolant supply line (7).