TWI458568B - Modification method of appearance property by using ultraviolet - Google Patents

Description

Method for modifying surface characteristics by using ultraviolet light

This invention relates to a surface treatment method, and more particularly to a method of modifying surface characteristics using ultraviolet light.

In the release technology of the conventional flexible substrate, the method includes: (1) fully bonding an adhesive layer between the flexible substrate and the carrier, and the adhesive layer is used after the process is finished, and the adhesive layer is used, for example, low temperature. Loss of adhesion, high temperature cracking by laser or ultraviolet light, so as to reduce the adhesion to achieve the release effect; (2) to be attached to the flexible substrate and the carrier with a release material, to be processed After the end, the surrounding area of the release material is cut, and the low adhesion force of the release material is utilized to achieve the purpose of release.

However, the above-mentioned release technology is achieved by utilizing the material properties of the adhesive layer or the release material, and the selection of the material must consider the adhesion and the reworkability of the carrier plate, and the limitation is large. In general, in order to improve the adhesion of the material, it is necessary to improve the material composition, and it is often to improve the chemical bonding with the carrier. However, the adhesion is too high to be easily removed, which causes troubles in the inconvenience of heavy work when the carrier is recycled in the future.

The invention relates to a method for modifying the surface characteristics by using ultraviolet light, which can modify and clean the partial surface of the carrier plate, improve the adhesion of the coating material, and improve the material selection of the existing adhesive layer or release material. The upper limit and the problem that the carrier board is difficult to rework.

According to one aspect of the invention, a method of modifying surface characteristics using ultraviolet light is provided, including the following steps. A carrier plate is placed in the illuminated area of a light source. A portion of the surface of the carrier is shielded by a mask to define a light receiving area and a non-light receiving area. The light-receiving area is modified by a light source so that the light-receiving area is wetted to a greater extent than the non-light-receiving area. A substrate is coated on the carrier.

In order to better understand the above and other aspects of the present invention, the preferred embodiments are described below, and in conjunction with the drawings, the detailed description is as follows:

The method for modifying the surface characteristics of the present embodiment can be applied to a method for fabricating a flexible substrate, mainly by irradiating a partial surface of the carrier with ultraviolet light (or deep ultraviolet light) for modification and cleaning. Ultraviolet light having a wavelength of less than 200 nm causes a chemical reaction of oxygen in the air to generate ozone (O+O ₂ →O ₃ ). Ozone is photo-deoxidized in the light-receiving zone of the carrier under the irradiation of ultraviolet light with a wavelength of 254 nm to convert the organic molecules adhering to the surface into gas molecules and disappear into the air. Therefore, the surface after ultraviolet light irradiation and ozone cleaning has a better degree of wetting than the surface which is not irradiated with ultraviolet light and ozone. In the method for fabricating a flexible substrate, a substrate can be coated on the carrier by the surface characteristics of the modified substrate, so that the adhesion between the substrate and the carrier can be increased to a large extent. Force, not enough adhesion to cause separation from each other.

The following is a detailed description of various embodiments, which are intended to be illustrative only and not to limit the scope of the invention.

1A-1C are schematic views showing a method of modifying surface characteristics by using ultraviolet light according to an embodiment of the present invention. 2 is a flow chart showing the characteristics of surface modification by ultraviolet light according to an embodiment of the invention. Hereinafter, each step of the second drawing will be described with reference to Figs. 1A to 1C.

In FIG. 2, step S110 places a carrier 110 in an illumination area of a light source 100. Step S120 shields a portion of the surface of the carrier 110 with a mask 10 to define a light receiving region 112 and a non-light receiving region 114. In step S130, the light receiving area 112 is modified by ultraviolet light UV so that the light receiving area 112 is wetted to a greater extent than the non-light receiving area 114. Step S140 applies a substrate 120 to the carrier 110.

Referring to FIG. 1A, the light source 100 is, for example, a UV light source having a dominant wavelength of about 185 nm or 254 nm. The area covered by the reticle 10 is the non-light-receiving area 114, and the area not covered by the reticle 10 is the light-receiving area 112. The area of the carrier 110 can be defined by the size and location of the reticle 10. For example, the light receiving area 112 is located on the peripheral surface of the carrier 110, and the inner edge 113 is represented by the inner edge, and the non-light receiving area 114 is located in the area surrounded by the light receiving area 112. The position and size thereof can be adjusted according to the process requirements. Preferably, the area of the light receiving area 112 occupies about 1 to 5% of the total area of the carrier 110 or the minimum width of the inner edge 113 of the light receiving area 112 from the outer edge of the carrier 110 is about 5 mm, so that the carrier 110 is The light receiving area 112 has a sufficient bonding area. For example, it is a 620*750mm size carrier board, and the light receiving area is 5mm away from the outer edge of the carrier board, and its light receiving area accounts for about 3% of the total area.

In an embodiment, the material of the carrier 110 may be tempered glass, heat resistant glass, metal or acrylic. The power, illumination, and exposure time of the light source 100 can be adjusted depending on the material characteristics of the carrier 110. For example, the illumination area 112 has an illumination of about 2,000 to 3,000 mW per square centimeter and an exposure time of about 10 to 20 seconds.

Referring to FIG. 1B, through the light receiving region after ultraviolet irradiation, and UV ozone cleaning O ₃ 112, with respect to ultraviolet light without UV irradiation and ozone O ₃ cleaning of non-light-receiving region 114, due to different degrees and having different wetting surface characteristic.

The table below compares the cleaning method of the glass carrier and the wetting angle measurement structure.

In the comparison table, after the light-receiving region 112 is subjected to ultraviolet light UV modification, the measured wettability angle (contact angle) is less than 5 degrees. The non-light-receiving region 114 which is not modified by ultraviolet light UV has a measured wet angle of 15 to 20 degrees, which is larger than the wettability angle of the light-receiving region 112. In one embodiment, the wet angle of the non-light-receiving region 114 and the wetted angle of the light-receiving region 112 may differ by more than 10 degrees. The smaller the wetting angle, the greater the adhesion between the adhesive and the carrier 110, meaning that the molecular force (for example, van der Waals force) between the adhesive and the carrier 110 is larger, and conversely, the larger the wetting angle, The smaller the adhesion between the adhesive and the carrier 110, the more pronounced the effect of the release.

Therefore, in FIG. 1C, a substrate 120 can be coated on the carrier 110 by surface characteristics modified by the carrier 110. After the substrate 120 is cured, since the adhesion between the substrate 120 and the light receiving region 112 is greater than the adhesion between the substrate 120 and the non-light-receiving region 114, the substrate 120 and the carrier 110 can withstand a large effect. Force, not enough adhesion to cause separation from each other. In addition, when a part of the substrate 120 located in the non-light-receiving area 114 is cut, since the release ability between the substrate 120 and the light-receiving area 112 is smaller than the separation ability between the cut portion and the non-light-receiving portion 114 of the substrate, the release can be maintained. The effect of the substrate cutting portion and the carrier 110 can be directly separated, for example, physical separation, so that the carrier 110 can be easily recycled. The cut portion of the substrate 120 after being released can be used as a flexible substrate. In addition, due to the improvement of the wetting effect between the substrate 120 and the light receiving region 112, and the adhesion between the interfaces, the molecular force (for example, van der Waals force) is increased, which is a physical adhesion enhancement phenomenon. In the heavy-duty process of the carrier board, a relatively simple physical tear-off method can be used to achieve the rework effect, so that the carrier board 110 can be easily recycled.

In FIG. 1C, the material of the substrate 120 may be a thermoplastic resin such as polyimide or polyethylene terephthalate (PET), which can be applied to a flexible display. The substrate 120 is uniformly coated on the carrier 110 with a bar 20 or a bar to form a film. Further, the substrate 120 may be uniformly coated on the carrier 110 by spin coating or slit coating to form a film. The thickness of the film is about 5 to 20 microns.

For the release technology of the conventional flexible substrate, the present embodiment uses the UV-modified carrier to fabricate a flexible substrate, without using a special material adhesive layer or release material, but improving the material for the carrier. The degree of wetting increases the adhesion between the interfaces, that is, improves the adhesion between the flexible substrate and the carrier, and achieves the effect of easily recycling the carrier for reuse.

In conclusion, the present invention has been disclosed in the above preferred embodiments, and is not intended to limit the present invention. A person skilled in the art can make various changes and modifications without departing from the spirit and scope of the invention. Therefore, the scope of the invention is defined by the scope of the appended claims.

10. . . Mask

20. . . Scraper

100. . . light source

110. . . Carrier board

112. . . Light receiving area

114. . . Non-light receiving area

120. . . Substrate

UV. . . Ultraviolet light

1A-1C are schematic views showing a method of modifying surface characteristics by using ultraviolet light according to an embodiment of the present invention.

2 is a flow chart showing the characteristics of surface modification by ultraviolet light according to an embodiment of the invention.

S110～S140. . . Various steps

Claims (9)

A method for modifying surface characteristics by using ultraviolet light comprises: placing a carrier plate in an illumination area of a light source; shielding a part of the surface of the carrier plate with a mask to define a light receiving area and a non-light receiving area; Ultraviolet light is modified to light the light-receiving area to make the light-receiving area moist than the non-light-receiving area; and a substrate is coated on the carrier, wherein the substrate and the light-receiving area are separated The type capability is less than the release ability between the substrate and the non-light-receiving region. The method of claim 1, wherein the substrate is uniformly coated on the carrier by a bar or a roller to form a film. The method of claim 1, wherein the substrate is uniformly coated on the carrier by spin coating or slit coating to form a film. The method of claim 1, wherein the adhesion between the substrate and the light-receiving region is greater than the adhesion between the substrate and the non-light-receiving region. The method of claim 1, wherein the step of modifying the light-receiving region comprises cleaning the light-receiving region by ozone generated by the light source reacting with oxygen in the air. The method of claim 1, wherein the source has a wavelength of 254 nm or 185 nm. The method of claim 1, wherein the light receiving area has an illumination of 2000 to 3000 mW per square centimeter and an exposure time of 10 ~20 seconds. The method of claim 1, wherein the light-receiving area has a wetting angle of less than 5 degrees, and the non-light-receiving area has a wetting angle of between 15 and 20 degrees. The method of claim 1, wherein the non-light-receiving zone has a wetting angle that is different from the wetting angle of the light-receiving zone by more than 10 degrees.