Epoxy Adhesive for Semiconductor Packages

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Solution Overview

Problem

High-voltage semiconductor devices face challenges with warpage, corona discharge, and performance degradation due to thermal effects, water absorption, and improper encapsulant thickness, leading to reliability issues and early life failure in packaging technologies.

Innovation Solution

A novel epoxy encapsulating and lamination adhesive is developed using a hardener blend of trioxdiamine, diaminodicyclohexylmethane, toluene diamine, and bisphenol-A dianhydride, which is mixed with an epoxy resin to form an uncured adhesive mixture that is then cured, providing a high breakdown voltage and low parasitic inductance, suitable for semiconductor device packages.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a standard encapsulant is applied to protect high-voltage assemblies, then protection from external influences is provided, but warpage occurs due to thermal effects and water absorption

Engineering Contradiction:
Improveprotection from external influencesVSAvoidwarpage
Core Design Contradiction:
Object-affected harmful factorsVSShape

Solution Approach 1:

The patent employs a composite encapsulant system consisting of a low-viscosity epoxy adhesive mixture combined with a specific hardener blend (trioxdiamine, diaminodicyclohexylmethane, toluene diamine, and bisphenol-A dianhydride). This composite material formulation provides enhanced dimensional stability and resistance to warpage while maintaining protective functions against thermal effects and water absorption.

Inventive Principle:
Principle #40Composite materials

2Reliability

If an encapsulant is applied too thinly or too thickly, then coverage is achieved, but corona discharge and sparking occur during high-voltage operation

Engineering Contradiction:
Improvehigh-voltage operation stabilityVSAvoidcorona discharge and sparking
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent utilizes parameter changes in the encapsulant formulation, specifically controlling the viscosity, thickness, and compositional ratios of the epoxy adhesive mixture and hardener blend. By optimizing these parameters, the encapsulant achieves uniform thickness that prevents corona discharge and sparking while ensuring complete coverage and reliable high-voltage operation.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If a high dielectric material with increased thickness is used for dielectric isolation, then high reverse breakdown voltage is achieved, but parasitic inductance increases

Engineering Contradiction:
Improvereverse breakdown voltageVSAvoidparasitic inductance
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent achieves the optimal balance between dielectric strength and parasitic inductance by precisely controlling the thickness and compositional parameters of the encapsulant layer. The formulated epoxy adhesive mixture with the specific hardener blend provides sufficient dielectric isolation for high reverse breakdown voltage while maintaining controlled thickness to minimize parasitic inductance in the power electronic circuit.

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 adhesive solution effectively prevents warpage, reduces parasitic inductance, and enhances dielectric strength, enabling stable high-voltage operation with improved reliability and reduced switching time, while allowing for efficient laser ablation and controlled thickness, thus addressing the limitations of existing encapsulants.

Implementation Method 1

mixing the hardener with an epoxy resin to form an uncured adhesive mixture, and curing the uncured adhesive mixture

Methodology Applied
Scientific EffectChemical Bonding: Chemical Bonding

Implementation Method 2

because of thermal effects, water absorption, and the like, such an assembly is prone to warpage

Methodology Applied
Scientific EffectThermal Energy Storage: Thermal Energy Storage

Implementation Method 3

because of thermal effects, water absorption, and the like, such an assembly is prone to warpage

Methodology Applied
Scientific EffectAbsorption (physical): Absorption (physical)

Implementation Method 4

an encapsulant is often applied, which is then laser ablated in order to electrically connect to the ground or power plane

Methodology Applied
Scientific EffectAbsorption (EM radiation): Absorption (EM radiation)

Data Source

PatentEP2559732B1Epoxy encapsulating and lamination adhesive and method of making same
Publication Date: 2017.04.26 GENERAL ELECTRIC CO
  • EP2559732B1 patent drawingFigure 1
  • EP2559732B1 patent drawingFigure 2~3
  • EP2559732B1 patent drawingFigure 4A~4C

AI summary

An adhesive includes an epoxy resin and a hardener. The hardener includes trioxdiamine, diaminodicyclohexylmethane, toluene diamine, and bisphenol-A dianhydride.