Resin-Junction Body Laser Welding via Transparent Mediator

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Solution Overview

Problem

Existing resin-welding methods fail to effectively join resin members when both materials absorb laser light, as the laser light is absorbed by the first resin material before reaching the second resin material, preventing adequate welding.

Innovation Solution

A resin-junction body comprising a first resin member, a second resin member with a concave portion, and an optically transparent third resin member, where the third resin member is placed in the concave portion to allow laser light to pass through and absorb heat, facilitating the welding of the first and second resin members by extending the fusing region and ensuring secure fusion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If both the first resin material and the second resin material have light-absorbing properties, then the resin members can be joined with light-absorbing materials providing design flexibility, but the laser light will be absorbed by the first resin material before reaching the second resin material, preventing adequate welding

Engineering Contradiction:
Improvedesign flexibilityVSAvoidwelding quality
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

A transparent member is inserted into a hole formed in the second resin material to serve as an intermediary. This transparent member allows laser light to pass through and reach the second resin material, enabling adequate welding while maintaining the use of light-absorbing materials for both resin members. The transparent member acts as a mediator that transmits the welding light without absorbing it, solving the contradiction between using versatile light-absorbing materials and achieving reliable welding.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If a hole is formed in the second resin material to insert a transparent member, then light transmission and welding quality are improved, but the device complexity and manufacturing steps increase

Engineering Contradiction:
Improvewelding qualityVSAvoidstructure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The hole for inserting the transparent member is formed in advance during the molding process of the second resin material, before the welding operation. This preliminary action integrates the hole formation into the existing manufacturing workflow, minimizing additional complexity. The transparent member is then simply inserted into this pre-formed hole, making the overall process straightforward despite the additional component.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If the transparent member is inserted into the hole of the second resin material, then heat conduction and welding effectiveness are improved, but the manufacturing precision requirements increase

Engineering Contradiction:
Improvewelding effectivenessVSAvoidpositioning accuracy
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The transparent member is designed with optical properties that allow it to be visually distinguished during assembly, facilitating accurate positioning. The contrast between the transparent member and the surrounding resin material enables operators to easily align and insert the transparent member into the correct hole position, reducing the practical precision requirements despite the critical nature of the welding process.

Inventive Principle:
Principle #32Color 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

Enables the secure welding of resin members with low optical transparency and light-absorbing properties by using an optically transparent member to transmit light and conduct heat, preventing heat escape and ensuring a strong, airtight joint.

Implementation Method 1

an optically transparent third resin member, where the third resin member is placed in the concave portion to allow laser light to pass through

Methodology Applied
Scientific EffectLight transmission: Light

Implementation Method 2

both the first resin material and the second resin material have the quality of absorbing laser light

Methodology Applied
Scientific EffectLight absorption: Absorption (EM radiation)

Implementation Method 3

ensuring a strong, airtight joint

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP2894023B1Resin-junction body
Publication Date: 2019.05.01 FUNAI ELECTRIC CO LTD
  • EP2894023B1 patent drawingFigure 1
  • EP2894023B1 patent drawingFigure 2
  • EP2894023B1 patent drawingFigure 3

AI summary

A resin-junction body (501) includes a first resin member (10), a second resin member (520) including a concave portion (521) and laminated on the first resin member (10) so as to contact the first resin member at a contact surface. The concave portion (521) comprises a bottom face (521b) on a first resin member side. The resin-junction body (501) further includes a joining layer that joins the first resin member (10) and the second resin member (520) and that extends from the bottom face (521b) towards the first resin member.