Power Semiconductor Module Interface Layer for Thermal Bonding

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Solution Overview

Problem

Existing power semiconductor modules face challenges in achieving optimal thermal conductivity and reliable bonding to heat sinks, as conventional heat-conducting materials do not adequately address thermal bottlenecks and operational temperature ranges.

Innovation Solution

A power semiconductor module with a heat-conducting layer made of a metallic and non-eutectic material that is solid below a first threshold temperature, viscous between the first and second threshold temperatures, and fluid above the second threshold temperature, providing improved thermal conductivity and bonding by filling gaps and maintaining inter-metallic phonon-coupling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional heat-conducting materials are used, then thermal conductivity is achieved, but bonding reliability and gap filling are insufficient

Engineering Contradiction:

Improvebonding reliabilityVSAvoidmaterial property complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies parameter changes by utilizing the temperature-dependent physical state changes of the metallic non-eutectic material. The material transitions from solid at room temperature to viscous at elevated temperatures (above first threshold temperature), enabling it to fill gaps and conform to surface irregularities during the bonding process, thereby improving bonding reliability and gap filling without requiring complex multi-material systems

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent employs composite material characteristics by using a metallic non-eutectic material that exhibits multiple physical states (solid, viscous, fluid) within different temperature ranges. This single material provides both structural support when solid and gap-filling/bonding capabilities when viscous or fluid, effectively combining multiple functional properties that would otherwise require separate materials

Inventive Principle:

Principle #40Composite materials

2Temperature

If high thermal conductivity materials are used, then heat dissipation is improved, but adaptability to temperature ranges and gap filling are compromised

Engineering Contradiction:

Improvethermal conductivityVSAvoidtemperature range adaptability

Core Design Contradiction:

TemperatureVSAdaptability or versatility

Solution Approach 1:

The patent applies dynamics by using a material whose physical properties dynamically change with temperature. The metallic non-eutectic material remains solid at operating temperatures to maintain thermal conductivity, but becomes viscous above the first threshold temperature during bonding, enabling adaptive gap filling and surface conforming. This dynamic property change allows the same material to serve multiple functions across different temperature ranges

Inventive Principle:

Principle #15Dynamics

3Ease of manufacture

If eutectic materials are used, then bonding at specific temperature is achieved, but thermal conductivity across operational temperature range is insufficient

Engineering Contradiction:

Improvebonding process simplicityVSAvoidthermal conductivity

Core Design Contradiction:

Ease of manufactureVSTemperature

Solution Approach 1:

The patent uses parameter changes by selecting a metallic non-eutectic material that maintains solid state at operating temperatures, ensuring consistent thermal conductivity across the operational temperature range. The material transitions to viscous state above a specific threshold temperature during the bonding process, providing ease of manufacture through simplified bonding without requiring precise eutectic temperature control, thus resolving the contradiction between bonding simplicity and thermal conductivity

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

The solution enhances thermal conductivity and bonding between the power semiconductor module and the heat sink, effectively reducing thermal bottlenecks and ensuring reliable heat dissipation across the operational temperature range.

Implementation Method 1

Heat that is generated by the controllable semiconductor components is dissipated through the substrate and further through an (optional) base plate to a heat sink. A heat-conducting layer is usually arranged between the substrate and the heat sink... to effectively conduct the heat away from the substrate.

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

maintaining inter-metallic phonon-coupling

Methodology Applied

Scientific EffectPhonon coupling:

Data Source

PatentUS20230369166A1Power semiconductor module arrangement and method for producing the same

Publication Date: 2023.11.16 INFINEON TECH AUSTRIA AG

AI summary

A power semiconductor module arrangement includes a power semiconductor module, wherein the power semiconductor module includes a substrate for carrying at least one semiconductor body, and a heat-conducting layer arranged on a lower surface of the power semiconductor module, wherein the lower surface of the power semiconductor module is a surface that is configured to be mounted to a heat sink, and wherein the heat-conducting layer consists of a metallic and non-eutectic material that is solid at temperatures below a first threshold temperature, that is viscous at temperatures above the first threshold temperature and below a second threshold temperature, and that is fluid at temperatures above the second threshold temperature.