Semiconductor Adhesive Composition for Void-Free Chip Mounting

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Solution Overview

Problem

In the process of mounting and temporarily fixing multiple semiconductor chips on a mount-receiving member using an adhesive for semiconductors, voids often remain in the adhesive, which can affect the connection reliability between semiconductor chips and substrates or between semiconductor chips themselves.

Innovation Solution

The development of an adhesive for semiconductors comprising a thermoplastic resin, a thermosetting resin, a curing agent with a reactive group, and a flux compound with an acid group, where the calorific value at 60° C. to 155° C. on a DSC curve is 20 J/g or less, and the weight average molecular weight of the thermoplastic resin is 10000 or more.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If an adhesive for semiconductors is used to temporarily fix multiple semiconductor chips on a mount-receiving member, then the chips can be mounted and fixed, but voids remain in the adhesive affecting connection reliability

Engineering Contradiction:

Improveconnection reliabilityVSAvoidvoid formation in adhesive

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The patent changes the chemical composition parameters of the adhesive by incorporating a fluxing agent and controlling the ratio of thermoplastic to thermosetting resin. This modifies the adhesive's flow characteristics and curing behavior to reduce void formation during the mounting process while maintaining connection reliability.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The adhesive is formulated as a composite material containing multiple components: thermoplastic resin, thermosetting resin, and fluxing agent. This composite structure allows the adhesive to exhibit both flowability for void elimination and adequate strength for reliable connection.

Inventive Principle:

Principle #40Composite materials

2Ease of operation

If the adhesive flows well during temporary fixing, then chips can be positioned accurately, but voids may remain after curing

Engineering Contradiction:

Improvechip positioning accuracyVSAvoidreflow reliability

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The adhesive maintains continuous useful action by remaining flowable during chip positioning and then transitioning to a cured state that eliminates voids. The fluxing agent ensures continuous improvement of wetting properties throughout the process, allowing accurate positioning followed by void-free curing.

Inventive Principle:

Principle #20Continuity of useful action

3Reliability

If a fluxing agent is incorporated into the adhesive to remove oxide films, then connection reliability improves, but the adhesive composition becomes more complex

Engineering Contradiction:

Improveconnection reliabilityVSAvoidadhesive composition complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the fluxing agent function with the adhesive base material into a single integrated composition. This combination eliminates the need for separate flux application steps while maintaining the oxide-removing capability, thus improving connection reliability without proportionally increasing complexity.

Inventive Principle:

Principle #5Merging (Combining)

4Reliability

If the adhesive is cured at high temperature to eliminate voids, then reflow reliability improves, but the mounting process becomes more complex

Engineering Contradiction:

Improvereflow reliabilityVSAvoidmounting process complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The adhesive performs preliminary action by flowing and positioning chips accurately at lower temperatures before final curing. This preliminary flow phase establishes proper chip positions and eliminates major voids, so that subsequent high-temperature curing only needs to complete the void elimination and achieve final bond strength.

Inventive Principle:

Principle #10Preliminary action

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 adhesive effectively reduces voids in the semiconductor chip mounting process, enhancing the reflow reliability of semiconductor devices and improving the connection reliability between semiconductor chips and substrates.

Implementation Method 1

a method of incorporating a fluxing agent into an adhesive for semiconductors has been proposed

Methodology Applied

Scientific EffectFluxing action:

Implementation Method 2

the adhesive for semiconductors is cured all together by reflow at a temperature higher than or equal to the melting point of the connection part

Methodology Applied

Scientific EffectCuring reaction:

Implementation Method 3

a semiconductor chip is temporarily fixed to a mount-receiving member by applying heat (about 60° C. to 155° C.) to a stage to the extent that the adhesive for semiconductors becomes flowable

Methodology Applied

Scientific EffectMelting: Melting

Data Source

PatentUS12283565B2Adhesive for semiconductor, production method therefor, and semiconductor device and production method therefor

Publication Date: 2025.04.22 RESONAC CORP

AI summary

An adhesive for semiconductors, the adhesive containing a thermoplastic resin, a thermosetting resin, a curing agent having a reactive group, and a flux compound having an acid group. The adhesive has a calorific value of 20 J/g or less at 60° C. to 155° C. on a DSC curve, which is obtained by differential scanning calorimetry involving heating the adhesive at a rate of temperature increase of 10° C./min.