Glycol-Coated Copper Fine Particles for High-Temperature Die Attach

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Solution Overview

Problem

Existing bonding materials for power semiconductor devices, such as solder and plate-like copper fine particles, face limitations in workability, require precise sizing and alignment, and lack adequate heat dissipation properties, especially at high temperatures.

Innovation Solution

Copper fine particles with a coating layer of glycol or glycol polymer, designed to maintain integrity and facilitate easy bonding, exhibit excellent heat dissipation and electric conductivity, even at high temperatures, by suppressing oxidation and enabling sintering.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If solder is used as a bonding material, then bonding strength is achieved, but the operating temperature is limited due to melting point constraints

Engineering Contradiction:

Improveoperating temperatureVSAvoidbonding reliability

Core Design Contradiction:

TemperatureVSReliability

Solution Approach 1:

The invention changes the material composition parameters by using copper fine particles (99.99% purity) with specific size distribution (D10: 0.5-2 μm, D50: 2-5 μm, D90: 5-10 μm) and controlling the particle size distribution width (σ: 0.8-1.2), enabling the bonding material to withstand high temperatures exceeding solder's melting point while maintaining bonding reliability

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention creates a composite bonding material consisting of copper fine particles combined with specific glass ceramics (containing PbO, SiO2, B2O3, Al2O3, and other oxides in specific ratios), which combines the high temperature resistance of copper with the bonding properties of glass ceramics, achieving both high operating temperature capability and reliable bonding

Inventive Principle:

Principle #40Composite materials

2Temperature

If plate-like bonding material is used, then high temperature resistance is achieved, but workability deteriorates due to sizing and alignment requirements

Engineering Contradiction:

Improvetemperature resistanceVSAvoidworkability

Core Design Contradiction:

TemperatureVSEase of operation

Solution Approach 1:

The invention transforms the bonding material from plate-like shape to spherical fine particles, which can be easily applied through painting or spraying methods without requiring precise sizing and alignment, significantly improving workability while maintaining high temperature resistance through the copper fine particle composition

Inventive Principle:

Principle #14Spheroidality (Curvature)

Solution Approach 2:

The invention changes the physical form parameter from plate-like to spherical particles with controlled size distribution (0.5-10 μm), enabling the material to be applied as a coating while maintaining the high temperature resistance properties of copper-based composition

Inventive Principle:

Principle #35Parameter changes

3Loss of energy

If conventional bonding materials are used, then bonding is achieved, but heat dissipation properties are insufficient

Engineering Contradiction:

Improveheat dissipationVSAvoidbonding durability

Core Design Contradiction:

Loss of energyVSReliability

Solution Approach 1:

The invention changes the thermal conductivity parameter by using copper fine particles (99.99% purity) which have superior thermal conductivity compared to solder and conventional bonding materials, achieving excellent heat dissipation properties while maintaining bonding durability through the glass ceramics matrix

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention creates a composite structure where copper fine particles provide high thermal conductivity pathways for heat dissipation, while the glass ceramics matrix provides bonding strength and structural stability, achieving both excellent heat dissipation and bonding durability

Inventive Principle:

Principle #40Composite materials

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 copper fine particles provide reliable bonding with high electric conductivity and heat dissipation, suitable for die attach applications, maintaining structural integrity and durability under high temperature conditions.

Implementation Method 1

exhibit excellent heat dissipation and electric conductivity, even at high temperatures, by suppressing oxidation and enabling sintering

Methodology Applied

Scientific EffectOxidation suppression: Oxidation

Implementation Method 2

exhibit excellent heat dissipation and electric conductivity, even at high temperatures

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 3

exhibit excellent heat dissipation and electric conductivity, even at high temperatures

Methodology Applied

Scientific EffectElectrical conduction: Conduction (electrical)

Implementation Method 4

enabling sintering

Methodology Applied

Scientific EffectSintering: Sintering

Data Source

PatentUS20260027618A1Fine copper particles and method for producing fine copper particles

Publication Date: 2026.01.29 NISSHIN SEIFUN GROUP INC

AI summary

There are provided copper fine particles applicable to die attach (die bonding) or the like and having excellent heat dissipation properties, as well as a method for producing the copper fine particles. The copper fine particles have a coating layer constituted of glycol or a glycol polymer. The glycol or the glycol polymer preferably has a molecular weight of 300 or less. The particle size measured by BET method is 20 to 400 nm.