Connecting Member Lamination for Fast Joining and Long Open Time

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Solution Overview

Problem

Existing methods for connecting members, such as those used in battery packs, face challenges in improving productivity due to long joining process times and limited open times, as well as difficulties in achieving high joining strength.

Innovation Solution

A method involving the use of a laminated body formed with a solid joining agent containing amorphous thermoplastic resin, specifically thermoplastic epoxy resin or phenoxy resin, which is heated and pressurized to melt and join metal members, under conditions of 100°C to 400°C and 0.01 MPa to 20 MPa, allowing for rapid joining and long open times.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If bolts are used to fasten holding plates to each other, then joining strength is achieved, but productivity deteriorates due to long joining process time

Engineering Contradiction:
Improvejoining strengthVSAvoidproductivity
Core Design Contradiction:
StrengthVSProductivity

Solution Approach 1:

The patent replaces the mechanical fastening system (bolts) with a thermal joining system using hot melt adhesive. The adhesive is applied in solid form and then melted by heating to achieve bonding, substituting mechanical assembly with thermal processing to reduce joining time and improve productivity while maintaining joining strength.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the physical state parameter of the joining agent from solid (bolted connection) to melted state (hot melt adhesive). By controlling temperature parameters (heating to melt the adhesive), the joining process is accelerated significantly compared to mechanical fastening, thereby improving productivity without sacrificing joint strength.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If conventional joining agents are used, then joining process can be performed, but open time is limited and flexibility in manufacturing process deteriorates

Engineering Contradiction:
Improveflexibility in manufacturing processVSAvoidopen time
Core Design Contradiction:
Adaptability or versatilityVSDuration of action of moving object

Solution Approach 1:

The patent applies the hot melt adhesive in solid form before the joining operation, allowing the adhesive to be positioned and prepared in advance. The actual bonding occurs when heating is applied, extending the open time and allowing more flexible scheduling of the joining process without compromising adhesive performance.

Inventive Principle:
Principle #10Preliminary action

3Ease of manufacture

If liquid adhesive is used for joining, then joining process can be performed, but joining process time increases due to application and drying time

Engineering Contradiction:
Improveease of joining processVSAvoidjoining process time
Core Design Contradiction:
Ease of manufactureVSLoss of time

Solution Approach 1:

The patent utilizes the phase transition of the hot melt adhesive from solid to liquid state through heating. The adhesive is applied in solid form (eliminating drying time) and then melted by applying heat during or after assembly to achieve bonding. This phase transition approach eliminates the drying step required for liquid adhesives, significantly reducing joining process time while maintaining ease of manufacture.

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

This method enhances productivity by reducing joining process time and increasing open time while achieving high joining strength, with the added benefits of recyclability and repairability, and prevents electrolytic corrosion between dissimilar metal members.

Implementation Method 1

a joining process of joining the first member and the second member by heating and pressurizing the laminated body to melt the solid joining agent

Methodology Applied
Scientific EffectMelting: Melting

Implementation Method 2

heating and pressurizing the laminated body to melt the solid joining agent

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 3

heating and pressurizing the laminated body to melt the solid joining agent

Methodology Applied
Scientific EffectPressurization: Pressurisation

Implementation Method 4

prevents electrolytic corrosion between dissimilar metal members

Methodology Applied
Scientific EffectElectrolytic corrosion prevention:

Data Source

PatentEP4640780A1Connecting member and method for manufacturing connecting member
Publication Date: 2025.10.29 RESONAC CORP
  • EP4640780A1 patent drawingFigure 1
  • EP4640780A1 patent drawingFigure 2
  • EP4640780A1 patent drawingFigure 3

AI summary

Provided is a method for manufacturing a connecting member capable of improving productivity, more specifically, achieving a short joining process time and long open-time. A method for manufacturing a connecting member consisting of a first connecting body 18 and a second connecting body 20 connected together, in which the first connecting body 18 has a first member 3 at one end and the second connecting body 20 has a second member 4 extending along the first member at one end, the method including: a pre-joining step for preparing a laminate formed of the first member 3, a solid joining agent mainly comprising an amorphous thermoplastic resin which is at least one selected from a thermoplastic epoxy resin and a phenoxy resin, and the second member 4, arranged in this order; and a joining step for heating and pressurizing the laminate to melt the solid joining agent and join the first member 3 and the second member 4. The epoxy equivalent of the amorphous thermoplastic resin is 1,600 or more, or the amorphous thermoplastic resin contains no epoxy groups and the heat of fusion of the amorphous thermoplastic resin is 15 J/g or less.