Thin Sheet Bonding Member for Void-Free Semiconductor Joining

Solution Overview

Problem

During the heating process of a bonding paste, solvent volatilization leads to cavities within the bonding portion, resulting in reduced bonding strength and heat dissipation performance.

Innovation Solution

A method for manufacturing a thin sheet-like bonding member involves applying a paste containing high melting point metal particles, low melting point metal particles, and a solvent to a base material, heating it below the melting point of the high melting point metal but above the low melting point metal, and then peeling off the bonding member to prevent solvent retention.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a paste containing solvent is used for bonding, then the paste can be applied and processed, but solvent remains trapped inside the bonding portion causing cavity formation that reduces bonding strength and heat dissipation performance

Engineering Contradiction:

Improvepaste applicabilityVSAvoidbonding strength

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent applies preliminary heating treatment to the paste before the actual bonding process. This preliminary action removes the solvent from the paste in advance, preventing cavity formation during bonding while maintaining the paste's applicability and bonding strength

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent extracts the solvent from the paste through preliminary heating treatment before bonding. By removing the harmful solvent component in advance, the bonding portion is prevented from forming cavities, thus maintaining bonding strength without sacrificing paste applicability

Inventive Principle:

Principle #2Taking out (Extraction)

2Ease of manufacture

If a paste containing solvent is used for bonding, then the paste can be applied and processed, but the trapped solvent reduces heat dissipation performance

Engineering Contradiction:

Improvepaste applicabilityVSAvoidheat dissipation performance

Core Design Contradiction:

Ease of manufactureVSLoss of energy

Solution Approach 1:

The patent applies preliminary heating treatment to the paste before the actual bonding process. This preliminary action removes the solvent from the paste in advance, preventing cavity formation during bonding while maintaining the paste's applicability and bonding strength

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent extracts the solvent from the paste through preliminary heating treatment before bonding. By removing the harmful solvent component in advance, the bonding portion is prevented from forming cavities, thus maintaining bonding strength without sacrificing paste applicability

Inventive Principle:

Principle #2Taking out (Extraction)

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 approach effectively suppresses the formation of cavities within the bonding portion, enhancing bonding strength and heat dissipation performance between conductor members and semiconductor elements.

Implementation Method 1

When the bonding material described above is heated, the second particles melt, wet and spread, and come into contact with the surfaces of the first particles, and thus both react with each other. As a result, an intermetallic compound having a melting point higher than the bonding temperature is formed. The low melting point metal is consumed by this reaction and disappears

Methodology Applied

Scientific EffectMelting: Melting

Implementation Method 2

During heating, a solvent included in a paste volatilizes inside the paste. After the volatilization, the solvent at the end of the paste is discharged outside a bonding portion, but the solvent in the central portion of the paste is not discharged outside because the periphery is surrounded by objects to be bonded and the paste at the end

Methodology Applied

Scientific EffectEvaporation: Evaporation

Data Source

PatentUS12330212B2Thin sheet-like connecting member and manufacturing method therefor, semiconductor device and manufacturing method therefor, and power conversion device

Publication Date: 2025.06.17 MITSUBISHI ELECTRIC CORP

AI summary

A method for manufacturing a thin sheet-like bonding member, including applying a paste including first particles including a first metal, second particles including a second metal having a lower melting point than the first metal, and a solvent to a surface of a base material made of a substance that does not react with the second metal; heating the paste at a temperature lower than a melting point of the first metal and higher than the melting point of the second metal to form a thin sheet-like bonding member on the surface of the base material; and peeling the thin sheet-like bonding member from the base material to obtain the thin sheet-like bonding member.