Liquid Release Layer Patterning Method for Rapid Photocuring

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Solution Overview

Problem

Conventional suspension optical shaping requires complex and time-consuming processes for pattern detachment from the release layer, involving lifting and lowering of the platform, and can result in incomplete curing near the dead zone due to oxygen inhibition.

Innovation Solution

A patterning method and apparatus that utilize a release material with a specific gravity greater than the patterning material, phase-separating to form distinct liquid layers, allowing light to be irradiated through the release layer for photocuring, eliminating the need for pattern detachment and reducing curing time.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the platform is lifted to detach the pattern from the release layer, then the pattern can be removed, but the process becomes complex and time-consuming

Engineering Contradiction:
Improvepattern detachmentVSAvoidprocess complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The invention extracts the release layer function from the tray bottom surface by introducing a separate liquid release material layer. This liquid layer can be easily removed or allowed to evaporate, taking the cured pattern with it, thus eliminating the need for complex platform lifting and detachment operations. The release function is separated from the structural tray component.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The liquid release material acts as an intermediary between the tray bottom surface and the photocurable material. This intermediary layer provides the release function during curing and pattern formation, then can be easily removed afterward. The intermediary simplifies the overall process by providing a dedicated release mechanism that doesn't require complex mechanical operations.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If the platform is lifted and lowered repeatedly, then the pattern can be detached and repositioned, but the process time increases significantly

Engineering Contradiction:
Improvepattern repositioningVSAvoidprocess time
Core Design Contradiction:
Ease of operationVSLoss of time

Solution Approach 1:

The liquid release material is applied to the tray bottom surface before photocuring begins. This preliminary action ensures that the release function is already in place, eliminating the need for subsequent platform lifting and repositioning operations. The release layer is prepared in advance to facilitate easy pattern removal after curing.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention enables continuous photocuring operations without interruption for platform lifting and lowering. The liquid release material allows the pattern to be cured continuously on the tray bottom surface, maintaining continuous useful action throughout the photocuring process, thereby significantly reducing total process time.

Inventive Principle:
Principle #20Continuity of useful action

3Use of energy by moving object

If oxygen flows into the tray from the bottom portion, then the tray can transmit light, but the curing reaction is inhibited near the dead zone

Engineering Contradiction:
Improvelight transmissionVSAvoidcuring completeness
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The liquid release material serves as an intermediary layer between the oxygen-permeable tray bottom and the photocurable material. This intermediary layer allows light to pass through while controlling oxygen diffusion to the curing zone. The release material layer acts as a barrier that prevents excessive oxygen from reaching the photocurable material, thereby maintaining curing reliability while preserving light transmission.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The liquid release material forms a thin film on the tray bottom surface that is permeable to light but can be controlled regarding oxygen permeability. This thin film structure allows optical energy to pass through for curing while limiting oxygen diffusion that would otherwise inhibit the curing reaction near the tray bottom dead zone.

Inventive Principle:
Principle #30Flexible shells and thin films

4Ease of operation

If a release layer is formed on the tray bottom surface, then the pattern can be released, but additional materials and steps are required

Engineering Contradiction:
Improvepattern releaseVSAvoidmaterial complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The liquid release material performs multiple functions: it provides the release function for pattern removal, serves as a barrier layer to control oxygen diffusion, and can be easily removed or evaporated after use. This multi-functional approach consolidates several required functions into a single material system, reducing overall material and process complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 easy and rapid formation of photocured patterns without detachment from the release layer, improving process efficiency and preventing material insufficiency near the dead zone, thus enhancing the speed and quality of optical shaping.

Implementation Method 1

supplying a release material in a liquid state having a first specific gravity d1 and the patterning material in a liquid state that has a second specific gravity d2 smaller than the first specific gravity d1 and phase-separates from the release material

Methodology Applied
Scientific EffectPhase separation:

Implementation Method 2

a first liquid layer of the release material is formed in contact with the bottom portion and also form, on the first liquid layer, a second liquid layer of the patterning material

Methodology Applied
Scientific EffectDensity gradient: Density Gradient

Implementation Method 3

irradiating light to the liquid film via the first liquid layer to photocure the liquid film and form a pattern

Methodology Applied
Scientific EffectPhotocuring: Photopolymerisation

Data Source

PatentEP3450142B1Patterning method and patterning device
Publication Date: 2021.06.16 NAGASE CHEMTEX CORPORATION
  • EP3450142B1 patent drawingFigure 1(i)~1
  • EP3450142B1 patent drawingFigure 2(a)~2(f)

AI summary

Disclosed is a patterning method, whereby a photocured pattern can be formed easily in a short time without detaching the photocured pattern (cured product) from a release layer. The method includes the steps of: (i) supplying a release material in a liquid state having a first specific gravity d1 and a patterning material in a liquid state that has a second specific gravity d2 smaller than the first specific gravity d1 and phase-separates from the release material to a patterning tray including a bottom portion having a light-exposed surface to form a first liquid layer of the release material in contact with the bottom portion and form, on the first liquid layer, a second liquid layer of the patterning material in contact with the first liquid layer, and thereby forming a liquid film of the patterning material in a vicinity of an interface of the second liquid layer with the first liquid layer; and (ii) irradiating light to the liquid film via the first liquid layer to photocure the liquid film and form a pattern.