3D Insert Molding of Flexible Circuits Without Component Stress

Solution Overview

Problem

Existing insert molding techniques fail to integrate a flexible substrate with electronic components into a three-dimensional shape.

Innovation Solution

A molding method and system that elastically deforms and holds a flexible substrate with a circuit and electronic components within a mold, followed by injecting thermoplastic resin to form a three-dimensional integrated product.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a flexible substrate with electronic components is integrated into a three-dimensional shape using existing insert molding techniques, then the manufacturing capability is improved, but the existing techniques fail to achieve this integration

Engineering Contradiction:

Improveintegration capability of flexible substrateVSAvoidstress on electronic components

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The flexible substrate is elastically deformed into the desired three-dimensional shape before the resin is injected into the mold. This preliminary deformation allows the substrate to be pre-positioned and pre-shaped, enabling subsequent resin injection to occur without subjecting the electronic components to excessive stress during the molding process.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The substrate holding device dynamically adjusts to hold the flexible substrate in its elastically deformed state during resin injection. The holding mechanism accommodates the flexible nature of the substrate while maintaining its three-dimensional configuration, allowing the substrate to flexibly adapt to the molding process without compromising component integrity.

Inventive Principle:

Principle #15Dynamics

2Manufacturing precision

If the flexible substrate is elastically deformed to match the three-dimensional shape, then the integration accuracy is improved, but the substrate must be held in a deformed state during molding

Engineering Contradiction:

Improveshape correspondence accuracyVSAvoidsubstrate holding mechanism

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The flexible substrate is elastically deformed into the desired three-dimensional shape before the resin is injected into the mold. This preliminary deformation allows the substrate to be pre-positioned and pre-shaped, enabling subsequent resin injection to occur without subjecting the electronic components to excessive stress during the molding process.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

A substrate holding device acts as an intermediary between the flexible substrate and the mold cavity. This device temporarily holds the substrate in its elastically deformed state during resin injection, providing the necessary support and positioning without requiring permanent modification to the substrate or complex integration of multiple holding mechanisms.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Productivity

If the mold is closed and resin is injected while the substrate is held in position, then the integration efficiency is improved, but the substrate must remain stable under injection pressure

Engineering Contradiction:

Improvemolding process efficiencyVSAvoidsubstrate stability under pressure

Core Design Contradiction:

ProductivityVSStrength

Solution Approach 1:

A substrate holding device acts as an intermediary between the flexible substrate and the mold cavity. This device temporarily holds the substrate in its elastically deformed state during resin injection, providing the necessary support and positioning without requiring permanent modification to the substrate or complex integration of multiple holding mechanisms.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The resin injection process utilizes controlled parameter changes, including gradual pressure application and temperature control, to fill the mold cavity while maintaining substrate stability. The injection parameters are optimized to accommodate the flexible substrate's mechanical properties, ensuring complete filling without causing substrate deformation or component damage.

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

Enables the integration of flexible substrates and resin into complex shapes while minimizing stress on electronic components, ensuring reliability and efficiency in manufacturing.

Implementation Method 1

elastically deforming the flexible substrate and holding the flexible substrate along a resin filling space of a mold

Methodology Applied

Scientific EffectElastic deformation: Elasticity

Data Source

PatentUS12521924B2Molding method

Publication Date: 2026.01.13 THE JAPAN STEEL WORKS LTD

AI summary

A molding method integrally molds thermoplastic resin and a flexible substrate mounted with a circuit and an electronic component on a flat plate having flexibility into a three-dimensional shape. The molding method includes the steps of determining an unfolded shape and circuit arrangement of the flexible substrate corresponding to the three-dimensional shape, elastically deforming and holding the flexible substrate along a resin filling space of a mold while the mold is being opened, and closing the mold and filling the resin filling space with thermoplastic resin.