CN-121973365-A - Device and method for preparing stress-free UV (ultraviolet) photocuring film based on PVA (polyvinyl alcohol) sacrificial layer

Abstract

The invention discloses a device and a method for preparing a stress-free UV light curing film based on a PVA sacrificial layer, and relates to the technical field of molding of UV light curing materials and preparation of viscoelastic bodies. According to the invention, through the integrated design of the PVA sacrificial layer, the flexible silica gel gasket and the transparent covering film, the preparation of the UV light-cured film with no edge effect, no stress demoulding, no sticky surface and high flatness is realized, and four pain points in the prior art are perfectly solved. The technical scheme has strong industrial application value, and is particularly suitable for a substrate or a packaging layer of a high-performance flexible electronic device.

Inventors

• WU WENJIN
• LIN CHUBIN
• RUAN PEI
• HU YONG

Assignees

• 安徽信息工程学院

Dates

Publication Date

20260505

Application Date

20260311

Claims (9)

1. 1. The stress-free UV light curing film preparation device based on the PVA sacrificial layer is characterized by comprising A base plate as a base support; The PVA sacrificial layer is coated on the surface of the bottom plate, is made of polyvinyl alcohol and has water solubility; the flexible elastic gasket is arranged on the PVA sacrificial layer and used for defining the shape and thickness of the injection cavity; the transparent covering film is covered on the flexible elastic gasket and is used for sealing the cavity and isolating air; a UV light source positioned above the transparent cover film; And the bottom plate and the transparent covering film are fixed by a clamp or a vacuum adsorption device, so that the cavity is ensured to be sealed.
2. 2. The device for preparing a PVA-sacrificial-layer-based stress-free UV light-cured film according to claim 1, wherein the base plate is made of glass slides, acrylic plates or aluminum alloy plates.
3. 3. The PVA-sacrificial-layer-based stress-free UV light-cured film preparation device according to claim 1, wherein the flexible elastic gasket is annular or frame-shaped, is made of silica gel with the Shore hardness of 30-70 degrees, and has the thickness of 0.1-5mm.
4. 4. The PVA-sacrificial-layer-based stress-free UV light-cured film preparation device according to claim 1, wherein the transparent cover film is made of PET, FEP or PMMA with a release layer, and has a thickness of 0.05-0.2mm, and is tightly attached to the edge of the flexible gasket.
5. 5. The PVA-based sacrificial layer-free UV-curable film production apparatus according to claim 1, wherein the UV light source has a wavelength of 365-405nm and a power density of 10-50mW/cm2.
6. 6. A preparation method of a stress-free UV light-cured film based on a PVA sacrificial layer is characterized by being applied to the device of any one of claims 1-5, and comprises the following steps of S1, preparing the PVA sacrificial layer, namely placing a PVA aqueous solution on the surface of a base plate, and then placing the base plate into an oven for drying to form the PVA sacrificial layer; s2, placing a flexible elastic gasket, namely placing the annular flexible silica gel gasket on the PVA sacrificial layer through tweezers to form a closed injection cavity; S3, injecting UV light curing resin, namely slowly injecting the UV light curing resin into the cavity, wherein the liquid level of the resin is level with the top of the flexible elastic gasket; S4, covering and sealing the transparent film, namely covering the transparent covering film above the flexible elastic gasket, and fixing the bottom plate and the transparent covering film by using a clamp to enable the transparent covering film to be completely attached to the edge of the flexible elastic gasket; S5, UV curing, namely starting a UV light source, and radiating from above the transparent covering film to completely cure the resin; S6, removing the covering film and the spacer, namely gently tearing off the transparent covering film by using tweezers, and then separating the flexible elastic spacer from the cured film and the PVA sacrificial layer by using tweezers; And S7, removing the PVA sacrificial layer, namely putting the bottom plate, the PVA sacrificial layer and the solidified film into deionized water for soaking, naturally separating the solidified film from the bottom plate after the PVA is completely dissolved, taking out the film, flushing the film with the deionized water, and completely drying to obtain the UV light solidified film.
7. 7. The device for preparing a PVA-sacrificial-layer-based stress-free UV cured film according to claim 6, wherein the solvent of the PVA aqueous solution in the step S1 is deionized water, and the PVA aqueous solution is coated on the surface of the base plate by spin coating or drop coating.
8. 8. The apparatus for preparing a stress-free UV curable film based on a PVA sacrificial layer according to claim 6, wherein the drying temperature of the oven in step S1 is 60-80 ℃.
9. 9. The device for preparing a stress-free UV cured film based on a PVA sacrificial layer according to claim 6, wherein the temperature of deionized water in the step S7 is 20-40 ℃, and the soaking time is adjusted according to the dissolution condition of the PVA sacrificial layer.

Description

Device and method for preparing stress-free UV (ultraviolet) photocuring film based on PVA (polyvinyl alcohol) sacrificial layer Technical Field The invention relates to the technical field of UV light-cured material molding and viscoelastic body preparation, in particular to a device and a method for preparing a stress-free UV light-cured film based on a PVA sacrificial layer. Background With the development of micro-electro-mechanical systems, flexible electronics and medical minimally invasive technologies, the demand for ultra-thin UV light-cured viscoelastic films is growing due to their controllable viscoelastic properties, excellent adhesion and rapid curing characteristics. The film needs to meet the core requirements of uniform thickness, no adhesive residue on the surface and no curling deformation after molding, and the preparation process needs to avoid the influence of oxygen inhibition, high-temperature heat dissipation and other problems on the performance. The UV light curing technology has wide application in the preparation of functional films due to the advantages of high efficiency, energy conservation, environmental protection and the like. In order to realize thickness control, high flatness and stress-free demolding of the film, the following technologies, namely a doctor blade coating/slit coating combined direct stripping method, a roll-to-roll (R2R) UV embossing technology and the like are mainly adopted. The blade coating/slit coating method sets the film thickness by controlling the gap between the blade and the substrate, and often covers the transparent release film to inhibit oxygen inhibition, and the film is obtained by mechanical peeling after curing. Roll-to-roll technology is a technique whereby a film is continuously formed and cured on a flexible web by an embossing cylinder. These methods are widely used, but have significant drawbacks. The first disadvantage is that mechanical stress is easily introduced in the demolding process, and the tearing force of direct stripping can cause residual stress to the film, so that irreversible plastic deformation such as curling and edge curling can be caused, micro cracks can be even caused, and damage to carried precise functional layers (such as conductive circuits) can be caused. Secondly, the problem of edge effect is prominent, and in the blade coating process, the thickness of the film edge is obviously larger than that of the central area due to the hydrodynamic effect, and the thickness uniformity and reliability are seriously affected. The prior art generally removes edges by post-cutting, reducing material utilization and efficiency. In addition, oxygen inhibition causes surface defects, namely oxygen inhibition can occur when the surface of the resin contacts with air in the UV curing process, so that the surface is sticky and the curing is incomplete; Finally, the surface flatness is insufficient, the traditional process has no flatness constraint layer, the resin is easy to generate surface fluctuation due to shrinkage when being solidified, and the requirement of the flexible electronic device on the high flatness of the substrate can not be met. Disclosure of Invention The invention aims to provide a device and a method for preparing a stress-free UV light-cured film based on a PVA sacrificial layer, which overcome the defects in the prior art. Stress-free UV light-cured film preparation device based on PVA sacrificial layer comprises A base plate as a base support; The PVA sacrificial layer is coated on the surface of the bottom plate, is made of polyvinyl alcohol and has water solubility; the flexible elastic gasket is arranged on the PVA sacrificial layer and used for defining the shape and thickness of the injection cavity; the transparent covering film is covered on the flexible elastic gasket and is used for sealing the cavity and isolating air; a UV light source positioned above the transparent cover film; And the bottom plate and the transparent covering film are fixed by a clamp or a vacuum adsorption device, so that the cavity is ensured to be sealed. Preferably, the bottom plate is made of glass slides, acrylic plates or aluminum alloy plates. Preferably, the flexible elastic gasket is annular or frame-shaped, is made of silica gel with the Shore hardness of 30-70 degrees, and has the thickness of 0.1-5mm. Preferably, the transparent covering film is made of PET, FEP or PMMA with a release layer, and has a thickness of 0.05-0.2mm, and is tightly attached to the edge of the flexible gasket. Preferably, the wavelength of the UV light source is 365-405nm, and the power density is 10-50mW/cm < 2 >. S1, preparing a PVA sacrificial layer, namely placing a PVA aqueous solution on the surface of a base plate, and then placing the base plate in an oven for drying to form the PVA sacrificial layer; s2, placing a flexible elastic gasket, namely placing the annular flexible silica gel gasket on the PVA sacrificial la