Phase-Change Metal TIM Assembly for Oxidation-Resistant Heat Transfer

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing thermal interface materials (TIMs) face challenges in providing effective heat dissipation for high-density integrated circuit (IC) devices due to issues such as low thermal conductivity, degradation with temperature and thermal cycling, and oxidation, while metal foils fail to conform to surface irregularities, leading to poor temperature distribution.

Innovation Solution

Phase change metal alloys (PCMAs) comprising indium, bismuth, and zinc, optionally with additional elements like silver, copper, and germanium, are used in combination with a thermally conductive metal foil to create a compliant, conductive interface that adapts to surface irregularities and offers improved oxidation resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If phase-change materials (PCMs) are used as TIMs, then stability in the interface is improved, but thermal performance deteriorates due to increased thickness

Engineering Contradiction:

Improveinterface stabilityVSAvoidthermal performance

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The patent changes the physical state parameter of the TIM by using a phase-change material that transitions from solid to liquid at operating temperatures. This allows the material to maintain stability in solid form during handling and assembly, then transform to liquid form during operation to achieve superior thermal conductivity and conformability, thereby resolving the contradiction between interface stability and thermal performance.

Inventive Principle:

Principle #35Parameter changes

2Loss of energy

If low melting alloys (LMAs) are used to form continuous liquid metal film, then thermal conductivity is improved, but performance deteriorates due to oxidation

Engineering Contradiction:

Improvethermal conductivityVSAvoidoxidation degradation

Core Design Contradiction:

Loss of energyVSObject-affected harmful factors

Solution Approach 1:

The patent employs a composite structure consisting of a phase-change material core surrounded by an oxidation-resistant metal alloy layer. This composite design allows the inner PCM to provide superior thermal conductivity while the outer protective layer prevents oxidation, thereby resolving the contradiction between thermal conductivity and oxidation resistance.

Inventive Principle:

Principle #40Composite materials

3Ease of operation

If metal foils are used as TIMs, then ease of application is improved, but thermal performance deteriorates due to poor conformance to surface irregularities

Engineering Contradiction:

Improveease of applicationVSAvoidthermal performance

Core Design Contradiction:

Ease of operationVSLoss of energy

Solution Approach 1:

The patent introduces dynamic adaptability by using a phase-change material that can transition from a rigid solid state (easy to handle and apply) to a fluid liquid state (able to conform to surface irregularities). This dynamic state change allows the TIM to maintain both ease of application and superior thermal performance through automatic adaptation to surface topography.

Inventive Principle:

Principle #15Dynamics

4Ease of operation

If polymer TIMs are used, then ease of application is improved, but thermal conductivity deteriorates

Engineering Contradiction:

Improveease of applicationVSAvoidthermal conductivity

Core Design Contradiction:

Ease of operationVSLoss of energy

Solution Approach 1:

The patent utilizes phase transition phenomena where the TIM material transitions from solid to liquid at operating temperatures. This phase change enables the material to achieve liquid metal-like thermal conductivity when molten, while maintaining the ease of application characteristics of solid polymer materials during handling and assembly, thereby resolving the contradiction between ease of application and thermal conductivity.

Inventive Principle:

Principle #36Phase transitions

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 PCMAs provide superior thermal conductivity and conformability, maintaining effective heat transfer even under thermal cycling and oxidation, while the combination with a metal foil enhances oxidation resistance and adaptability to surface distortions.

Implementation Method 1

Phase change metal alloys (PCMAs) comprising indium, bismuth, and zinc... provide superior thermal conductivity and conformability

Methodology Applied

Scientific EffectPhase change: Phase Change

Implementation Method 2

a thermally conductive foil... The PCMAs provide superior thermal conductivity

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 3

These points of contact are plastically deformed against the surfaces and uniformly distributed

Methodology Applied

Scientific EffectPlastic deformation: Plasticity

Data Source

PatentUS20260062772A1Phase change metal alloys and thermal interface material assembly combining a patterned metal foil with a phase change metal alloy

Publication Date: 2026.03.05 INDIUM CORP

AI summary

Phase change metal alloys and their uses as thermal interface materials in electronic assemblies are described. In one implementation, a phase change metal alloy includes: 50 wt % to 70 wt % In; at least one of: 20 wt % to 40 wt % Bi and 10 wt % to 50 wt % Sn; and greater than 0 wt % to 5.0 wt % Zn. The phase change metal alloy can also include one or more of: greater than 0 wt % to 5.0 wt % Ga; greater than 0 wt % to 1.0 wt % Ag; greater than 0 wt % to 1.0 wt % Cu; greater than 0 wt % to 1.0 wt % Au; greater than 0 wt % to 0.1 wt % Ni; and greater than 0 wt % to 0.1 wt % Ge.