Coil Sheet Adhesive Layer Thermal Curing for Reliability

Solution Overview

Problem

Conventional coil sheets face issues with adhesive force, leading to separation or misalignment during energization due to either low or high adhesive strength, affecting the strength and reliability of the coil.

Innovation Solution

A coil sheet configuration with a conductor layer, thermally resistant organic insulating layer, and thermosetting adhesive layer in a B-stage state, where the adhesive layer is released from the base layer and thermally cured to enhance adhesion between radially adjacent portions, while maintaining releasability and matching thermal expansion coefficients to prevent separation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the adhesive force of the adhesive layer is increased to prevent separation of radially adjacent portions during energization, then the adhesion strength is improved, but the releasability of the adhesive layer from the base layer deteriorates

Engineering Contradiction:

Improveadhesion strengthVSAvoidreleasability

Core Design Contradiction:

StrengthVSEase of manufacture

Solution Approach 1:

The adhesive layer is applied to the base layer in advance during manufacturing, providing strong adhesion when needed, but the base layer can be easily removed before final assembly. This preliminary bonding ensures that when the base layer is removed, the adhesive layer remains firmly attached to the radially adjacent portions, preventing separation during energization while maintaining manufacturing ease

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The adhesive layer serves as an intermediary between the base layer and the radially adjacent portions. During manufacturing, it mediates the bonding process by allowing easy removal of the base layer. In the final product, it mediates the adhesion between radially adjacent portions, providing strong bonding that prevents separation during energization

Inventive Principle:

Principle #24Intermediary (Mediator)

2Ease of manufacture

If the adhesive force of the adhesive layer is decreased to maintain releasability from the base layer, then the ease of manufacture is improved, but the adhesion strength between radially adjacent portions deteriorates

Engineering Contradiction:

ImprovereleasabilityVSAvoidadhesion strength

Core Design Contradiction:

Ease of manufactureVSStrength

Solution Approach 1:

The adhesive layer is applied to the base layer in advance during manufacturing, providing strong adhesion when needed, but the base layer can be easily removed before final assembly. This preliminary bonding ensures that when the base layer is removed, the adhesive layer remains firmly attached to the radially adjacent portions, preventing separation during energization while maintaining manufacturing ease

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The adhesive layer serves as an intermediary between the base layer and the radially adjacent portions. During manufacturing, it mediates the bonding process by allowing easy removal of the base layer. In the final product, it mediates the adhesion between radially adjacent portions, providing strong bonding that prevents separation during energization

Inventive Principle:

Principle #24Intermediary (Mediator)

3Adaptability or versatility

If the thermal expansion coefficient of the conductor layer is made different from that of the insulating layer, then the material selection flexibility is improved, but the separation between conductor layer and insulating layer during energization increases

Engineering Contradiction:

Improvematerial selection flexibilityVSAvoidlayer separation

Core Design Contradiction:

Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The invention specifies that the thermal expansion coefficient of the conductor layer should be approximately equal to that of the insulating layer. This parameter matching prevents differential thermal expansion during energization, eliminating the stress that would cause separation between layers while maintaining structural integrity and electrical performance

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

The solution improves adhesion between laminate sheet portions, reduces misalignment, and increases the strength of the coil by thermally curing the adhesive layer, ensuring reliable performance during energization.

Implementation Method 1

the adhesive layer is thermally cured as a result of heating of the winding

Methodology Applied

Scientific EffectThermal curing: Heat Treatment

Implementation Method 2

the conductor layer may have a thermal expansion coefficient approximately equal to that of the insulating layer

Methodology Applied

Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentUS10832853B2Coil and coil production method

Publication Date: 2020.11.10 CKD CORP

AI summary

A coil sheet includes a conductor layer, a thermally resistant organic insulating layer, a thermosetting adhesive layer in a B-stage state, and a base layer, such that the conductor layer and the insulating layer are bonded to the base layer with the adhesive layer. A coil is formed of a laminate sheet including a conductor layer, an insulating layer, and an adhesive layer of the coil sheet which are released from the base layer thereof, wherein the laminate sheet is wound around a specific axis a plurality of times, and the adhesive layer is thermally cured.