Two-Stage Exposure Method for Photosensitive Resin Adhesion

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Solution Overview

Problem

Existing manufacturing methods for structures with photosensitive resins on substrates face issues with pattern defects due to foreign matter on the support, particularly when peeling off the support, which can damage the thin and uncured photosensitive layer, and result in poor adhesion and pattern defects.

Innovation Solution

A method involving a first exposure of the photosensitive layer via a support, followed by removal of the support, and a second exposure without the support using a photomask, to ensure proper curing and adhesion, thereby preventing pattern defects caused by foreign matter.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the photosensitive layer is exposed via the support, then the support provides structural support during handling, but foreign matter on the support causes pattern defects

Engineering Contradiction:

Improvestructural support during handlingVSAvoidpattern quality

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The exposure process is divided into two separate stages: first exposure via the support for adhesion formation, and second exposure via photomask for precise pattern formation. This segmentation allows each exposure to serve its specific function without interference from foreign matter on the support during the critical pattern formation stage.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The first exposure is performed as a preliminary action before the second exposure. This preliminary exposure pre-cures the photosensitive layer to ensure adhesion to the substrate, while the subsequent second exposure creates the precise pattern. The preliminary action ensures the photosensitive layer remains intact during support removal.

Inventive Principle:

Principle #10Preliminary action

2Ease of manufacture

If the support is peeled off after single exposure, then the photosensitive layer can be transferred to substrate, but the thin uncured photosensitive layer may be damaged

Engineering Contradiction:

Improvetransfer processVSAvoidphotosensitive layer integrity

Core Design Contradiction:

Ease of manufactureVSStrength

Solution Approach 1:

The first exposure is performed as a preliminary action before support removal to pre-cure the photosensitive layer. This preliminary curing provides sufficient strength and adhesion to prevent damage during support peeling, while allowing the transfer process to proceed easily.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The first exposure acts as a cushioning measure before the critical support removal step. By partially curing the photosensitive layer in advance, the method compensates for the vulnerability of the thin uncured layer during mechanical handling and peeling.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

3Device complexity

If single exposure is performed via support, then the process is simple, but pattern defects occur due to foreign matter

Engineering Contradiction:

Improveexposure processVSAvoidpattern quality

Core Design Contradiction:

Device complexityVSManufacturing precision

Solution Approach 1:

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

A photomask is introduced as an intermediary element for the second exposure. The photomask serves as a clean intermediate medium that transmits light patterns without the contamination issues present when using the support directly, thereby ensuring high pattern quality.

Inventive Principle:

Principle #24Intermediary (Mediator)

4Manufacturing precision

If the photosensitive layer is exposed twice, then pattern defects are prevented, but the manufacturing time increases

Engineering Contradiction:

Improvepattern qualityVSAvoidexposure process time

Core Design Contradiction:

Manufacturing precisionVSLoss of time

Solution Approach 1:

The two exposure steps are performed in continuous sequence without interrupting the overall manufacturing flow. The first exposure prepares the layer for transfer, and the second exposure immediately follows to create the pattern, maintaining continuous productive action throughout the process.

Inventive Principle:

Principle #20Continuity of useful action

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 adhesion and prevents pattern defects by ensuring the photosensitive layer remains intact during support removal and allows for precise pattern exposure, improving the reliability of the manufacturing process for structures like liquid ejection heads.

Implementation Method 1

performing first exposure of the first photosensitive layer bonded to the substrate via the first support; performing second exposure of the first photosensitive layer after the first support is removed via a photomask

Methodology Applied

Scientific EffectPhotopolymerization: Photopolymerisation

Data Source

PatentUS11465418B2Manufacturing method for structure and manufacturing method for liquid ejection head

Publication Date: 2022.10.11 CANON KK

AI summary

A manufacturing method for a structure includes preparing a dry film supported on one surface of a support; bonding the dry film to a substrate so that the dry film and the substrate are in contact with each other; performing first exposure of the dry film bonded to the substrate via the support; removing the support after the first exposure; performing second exposure of the dry film after the support is removed via a photomask; and developing the dry film after the first exposure and the second exposure.