Method for removing coating film, cutting glass and post-processing using laser

Abstract

A method for removing a coating film, cutting glass, and post-processing using a laser according to the present application includes the steps of: coating a coating solution for preventing chemical contact on one side or both sides of a mother panel state ultrathin glass to perform selective chemical processing; drying the coating solution to form a coating film on one side or both sides of the mother panel state ultrathin glass; cutting the mother panel state ultrathin glass into a unit level ultrathin glass applied to an electrical and electronic product; performing selective chemical processing on the cut unit level ultrathin glass to heal a laser cutting surface of the unit level ultrathin glass; after washing the unit level ultrathin glass, removing all of the coating film formed on a surface of the unit level ultrathin glass; and after washing the unit level ultrathin glass on which all of the coating film is removed, chemically healing the surface of the unit level ultrathin glass to remove defects or flaws on the surface of the unit level ultrathin glass on which all of the coating film is removed.

Description

Technical Field

[0001] This invention relates to a method for removing coatings, cutting glass, and post-processing using a laser. Specifically, it relates to a method for removing coatings, cutting glass, and post-processing using a laser, which uses a laser to cut coated master-plate ultrathin glass into cells, heals the cut surfaces of the cell-level ultrathin glass, removes the coating, and heals the surface of the cell-level ultrathin glass to make it flat, thereby manufacturing cell-level ultrathin glass for use in various electrical and electronic products. Background Technology

[0002] In recent years, due to the trend of thinner and lighter electronic products such as smartphones, traditional glass or acrylic is being replaced by ultra-thin glass.

[0003] This ultra-thin glass is used as a display window for portable electronic products such as mobile phones, PMPs, and MP3 players. The thinner the ultra-thin glass, the better its design and portability.

[0004] In order to manufacture unit-level ultra-thin glass for use in various electronic products, the ultra-thin glass in the mother plate state is cut into certain sizes.

[0005] At this point, microcracks or chipping that occur during the cutting process will reduce the strength of the cut unit-level ultrathin glass. To minimize this, additional face cutting and chamfering processes are required.

[0006] However, in this process, because the ultra-thin glass in the motherboard state is very thin, there is a risk of damage during the face cutting and chamfering processes. Furthermore, individual face cutting and chamfering of the unit-level ultra-thin glass used in the product requires a lot of manpower and time, resulting in excessive losses.

[0007] To address this problem, a method is proposed to join and stack ultra-thin glass in its motherboard state and then process it into a single unit.

[0008] The method for joining and stacking the ultra-thin glass in the motherboard state to form a whole includes a first embodiment using CNC machining and a second embodiment using laser beam machining. The first embodiment using CNC machining is described in detail below.

[0009] First, the first embodiment generally includes the following steps: stacking two or more mother-plate ultra-thin glass sheets, coating the two or more mother-plate ultra-thin glass sheets with a resin in a preset pattern to maintain a height gap; cutting the two or more stacked mother-plate ultra-thin glass sheets using CNC machining to cut the mother-plate ultra-thin glass sheets into unit-level ultra-thin glass sheets applicable to various electrical and electronic products; chemically healing the multiple stacked unit-level ultra-thin glass sheets to make the cut surfaces of the unit-level ultra-thin glass sheets flat; cleaning the healed unit-level ultra-thin glass sheets; completely curing the fluorine-coated resin between the unit-level ultra-thin glass sheets to make it easy to peel off; peeling off the resin adhering between the unit-level ultra-thin glass sheets; cleaning the unit-level ultra-thin glass sheets after removing the resin; chemically healing the cleaned unit-level ultra-thin glass sheets; cleaning the chemically healed unit-level ultra-thin glass sheets; strengthening the cleaned unit-level ultra-thin glass sheets before sending them to subsequent processes.

[0010] The step of stacking two or more ultra-thin glass substrates and coating the space between the two or more ultra-thin glass substrates with a resin in a predetermined pattern to maintain a height gap includes the following steps: Step 1-1, coating the upper surface of the ultra-thin glass substrates with resin; Step 1-2, after stacking the ultra-thin glass substrates on the coated resin, spreading the resin thinly; Step 1-3, curing the thinly spread resin with ultraviolet light; and repeating Step 1-1 to Step 1-3 to stack two or more ultra-thin glass substrates.

[0011] However, in the case of the first embodiment, it is necessary to perform the following processes: laminating two or more master-state ultra-thin glass sheets with resin; CNC cutting process including rough cutting, medium cutting and fine cutting processes for cutting the master-state ultra-thin glass sheets into unit-level ultra-thin glass sheets; process to make the cut surfaces of the unit-level ultra-thin glass sheets smooth by chemically healing the laminated unit-level ultra-thin glass sheets; process to make the resin completely cured so that the laminated unit-level ultra-thin glass sheets can be easily separated; cleaning process of the unit-level ultra-thin glass sheets after resin peeling; and cleaning process after chemically healing the unit-level ultra-thin glass sheets. Therefore, there are problems such as long manufacturing time and high production cost of unit-level ultra-thin glass sheets.

[0012] Next, the second embodiment will be described in detail.

[0013] The second embodiment of processing using a laser beam generally includes: a first step of irradiating the ultrathin glass in a motherboard state with a laser beam along the cutting line to cut the ultrathin glass in a motherboard state into unit-level ultrathin glass; a second step of stacking two or more cut unit-level ultrathin glass and coating the spacers between the stacked unit-level ultrathin glass with a resin for maintaining height spacing; a third step of chemically healing the two or more stacked unit-level ultrathin glass to make the cut surfaces of the cut unit-level ultrathin glass smooth; and a fourth step... The process involves several steps: first, cleaning the stacked unit-level ultrathin glass; second, fully curing the resin coated between the stacked unit-level ultrathin glass sheets to facilitate easy peeling; third, cleaning the separated unit-level ultrathin glass sheets after the resin is peeled off; fourth, chemically healing the cleaned unit-level ultrathin glass sheets; and fifth, cleaning the chemically healed unit-level ultrathin glass sheets, performing a strengthening process, and then sending them to subsequent processes.

[0014] Furthermore, the second step of stacking two or more cut unit-level ultrathin glass panes and coating the space between the vertically arranged unit-level ultrathin glass panes with a resin for maintaining a height gap includes: step 2-1, stacking two or more of the cut unit-level ultrathin glass panes and coating the space between a pair of vertically arranged unit-level ultrathin glass panes with a resin for maintaining a height gap; step 2-2, after stacking the unit-level ultrathin glass panes on the coated resin, spreading the resin thinly; step 2-3, curing the spread resin flat with ultraviolet light; and repeating steps 2-1 to 2-3 to stack two or more cut unit-level ultrathin glass panes.

[0015] However, the method using the laser beam requires steps such as stacking two or more cut unit-level ultrathin glasses with resin, completely curing the resin coated between the stacked unit-level ultrathin glasses, peeling off the resin and separating the stacked unit-level ultrathin glasses. Therefore, there are problems such as long manufacturing time and high production cost of unit-level ultrathin glasses.

[0016] Furthermore, CNC glass cutting methods can result in defects such as microcracks or chipping on the cut surface, while laser glass cutting and coating removal methods can cause thermal damage to the laser-irradiated area, making unit-level ultrathin glass susceptible to damage.

[0017] Defects such as microcracks or chipping caused by CNC machining, or thermal damage caused by lasers, can also lead to a decrease in flexural strength after strengthening of unit-level ultrathin glass.

[0018] To compensate for weak areas on CNC or laser-cut surfaces, resin is mainly used to stack multiple layers of unit-level ultrathin glass, and the cut surfaces are chemically treated to heal defects or thermal damage that occur during glass cutting, as in the first and second embodiments.

[0019] However, these surface treatment methods also have limitations, so it is necessary to ensure that damage to ultra-thin glass is minimized when using CNC or laser processes to cut it. However, this method suffers from reduced process applicability and increased processing time for unit-level ultra-thin glass used in various electrical and electronic products. If additional surface treatment processes are performed, the manufacturing process for unit-level ultra-thin glass becomes very complex, which may increase the cost of manufacturing the product.

[0020] Meanwhile, as prior art to this invention, there is Korean Patent Application No. 10-2010-0026394 entitled "Efficient Processing Method for Thin Glass Sheets", which includes the following steps: coating a bonding material between multiple stacked glass sheets to bond the multiple glass sheets together, and uniformly cutting the bonded glass sheets into block units; performing surface cutting processing on the thin sheet material of the block units; and polishing the cut surfaces by the rotational force of a brush and abrasive.

[0021] However, the efficient processing method for thin glass requires face cutting and polishing processes, which cannot completely remove defects such as microcracks or chipping from the cut surface of the thin glass. Content of the invention

[0022] The technical problem that the invention aims to solve

[0023] Therefore, the present invention is intended to solve the problems described above. One object of the present invention is to provide a method for removing coatings, cutting glass and post-processing using lasers, which can reduce the production costs of glass cutting and post-processing steps in the manufacture of unit-level ultra-thin glass (UTG) for various electrical and electronic products.

[0024] Furthermore, another object of the present invention is to provide a method for removing coatings, cutting glass and post-processing using lasers, thereby reducing the manufacturing cost of unit-level ultrathin glass by simplifying the manufacturing process when manufacturing unit-level ultrathin glass.

[0025] Furthermore, another object of the present invention is to provide a method for removing coatings, cutting glass and post-processing using lasers, which removes thermal damage around the glass cut surface that occurs during laser cutting and coating removal by selective chemical treatment, thereby improving the durability of the finished unit-level ultrathin glass.

[0026] Technical solutions for solving the problem

[0027] To achieve the aforementioned objective, the method for removing coatings, cutting glass, and post-processing using lasers according to the present invention comprises: step (S1), coating one or both sides of a base plate ultrathin glass 1 with a coating liquid for preventing contact with chemical substances to perform selective chemical treatment; step (S2), drying the coating liquid to form a coating film 2 on one or both sides of the base plate ultrathin glass 1; step (S3), irradiating the coating film 2 formed on any side of the base plate ultrathin glass 1 along a predetermined cutting line of the base plate ultrathin glass 1 with a laser beam to remove a portion of the coating film, and irradiating the surface of the base plate ultrathin glass 1 exposed to the outside by the coating removal portion A through the coating film 2 to cut the base plate ultrathin glass 1. The process involves: 1) cutting the ultra-thin glass 1 from its motherboard state into unit-level ultra-thin glass 5 for use in electrical and electronic products; 2) selectively chemically treating the cut unit-level ultra-thin glass 5 to heal the laser-cut surface of the unit-level ultra-thin glass 5, thereby removing thermal damage and defects around the cut surface of the unit-level ultra-thin glass 5 that occurred during the laser cutting process; 3) cleaning the unit-level ultra-thin glass 5 and then completely removing the coating 2 formed on its surface; and 4) chemically healing the surface of the unit-level ultra-thin glass 5 after cleaning it to remove any defects or blemishes on its surface after all the coating 2 has been removed. Step (S3) of irradiating a portion of the coating 2 formed on any side of the ultra-thin glass 1 in the motherboard state along a predetermined cutting line of the ultra-thin glass 1 in the motherboard state with a laser beam to remove it, and irradiating the surface of the ultra-thin glass 1 in the motherboard state exposed to the outside by the coating removal portion A after the coating 2 has been removed with a laser beam to cut the ultra-thin glass 1 in the motherboard state, thereby cutting the ultra-thin glass 1 in the motherboard state into unit-level ultra-thin glass 5 for use in electrical and electronic products, includes the following steps: when the coating 2 When the coating is formed only on one side of the ultra-thin glass 1 in the mother plate state, a laser beam (beam) output from an ultraviolet laser 4 that generates wavelengths below 400 nm is irradiated along the predetermined cutting line of the ultra-thin glass 1 in the mother plate state to remove the coating 2 along the predetermined cutting line of the ultra-thin glass 1 in the mother plate state, and a laser beam output from an infrared laser 3 that generates wavelengths above 1000 nm is irradiated on the ultra-thin glass 1 in the mother plate state exposed to the outside by the coating removal part A that has been removed by the coating 2 to cut the ultra-thin glass 1 in the mother plate state.Furthermore, the step (S3) of irradiating a portion of the coating 2 formed on any side of the ultra-thin glass 1 in the mother plate state along a predetermined cutting line of the ultra-thin glass 1 in the mother plate state with a laser beam to remove a portion of the coating 2, and then irradiating the surface of the ultra-thin glass 1 in the mother plate state exposed to the outside by the laser beam to cut the ultra-thin glass 1 in the mother plate state, thereby cutting the ultra-thin glass 1 in the mother plate state into unit-level ultra-thin glass 5 for use in electrical and electronic products, includes the following steps: when the coating 2 is formed on both sides of the ultra-thin glass 1 in the mother plate state. At that time, a laser beam (beam) output from an ultraviolet laser 4 producing wavelengths below 400 nm is irradiated along a predetermined cutting line of the motherboard ultrathin glass 1 onto the surface of a coating 2 formed on one side of the motherboard ultrathin glass 1, to remove a pair of coatings 2 facing each other in the thickness direction of the motherboard ultrathin glass 1 along the predetermined cutting line. A laser beam output from an infrared laser 3 producing wavelengths above 1000 nm is irradiated onto the motherboard ultrathin glass 1, where the coating removal section A, after the coatings 2 have been removed, is exposed to the outside, to cut the motherboard ultrathin glass 1. The infrared laser 3 is a nanosecond infrared laser 3, a picosecond infrared laser 3, or a femtosecond infrared laser 3, and the infrared laser 3 outputs a Bessel beam. The ultraviolet laser 4 is a nanosecond ultraviolet laser 4, a picosecond ultraviolet laser 4, or a femtosecond ultraviolet laser 4. In step (S4), which involves selectively chemically treating the cut surface of the unit-level ultrathin glass 5 to heal the laser-cut surface of the unit-level ultrathin glass 5 and remove thermal damage and defects around the cut surface of the unit-level ultrathin glass 5 that occurred during the laser cutting process, a beveled cutting portion 11 is formed at the right-angle corner of the unit-level ultrathin glass 5 that is in contact with the coating 2 surface by selective chemical treatment. The lateral width W of the beveled cutting portion 11 is 3 μm to less than 500 μm, and the height H of the beveled cutting portion 11 is more than 3 μm but does not exceed 50% of the thickness of the unit-level ultrathin glass 5.

[0028] The effects of the invention

[0029] The laser-based method for removing coatings, cutting glass, and post-processing, comprising this process, can reduce the manufacturing time and cost of unit-level ultrathin glass by simplifying the manufacturing process for unit-level ultrathin glass used in various electrical and electronic products.

[0030] Furthermore, the present invention can improve production efficiency by selectively chemically removing thermal damage around the glass cut surface caused by the laser beam during laser cutting and coating, thereby improving the durability of the finished unit-level ultrathin glass and reducing defects. Attached Figure Description

[0031] Figure 1 This is a process flow diagram of the present invention;

[0032] Figure 2 An embodiment of cutting a motherboard state of ultra-thin glass is shown, wherein when the coating is formed only on one side of the motherboard state of ultra-thin glass, the coating is first removed along the predetermined cutting line of the motherboard state of ultra-thin glass by a laser beam output from an ultraviolet laser, and then the laser beam output from an infrared laser is irradiated through the removal portion formed on the coating.

[0033] Figure 3 Another embodiment of cutting a mother-plate ultra-thin glass is shown, wherein when a coating is formed on both sides of the mother-plate ultra-thin glass, a laser beam output from an ultraviolet laser is first irradiated along a predetermined cutting line of the mother-plate ultra-thin glass to remove the coating adhering to both sides of the mother-plate ultra-thin glass, and then a laser beam output from an infrared laser is irradiated on the mother-plate ultra-thin glass through a removal section formed in the coating to cut the mother-plate ultra-thin glass.

[0034] Figure 4 This shows the beveled cut formed at the right-angle corner of the unit-level ultrathin glass after healing the cut unit-level ultrathin glass, which is in contact with the coating surface.

[0035] Explanation of reference numerals in the attached figures

[0036] 1: Motherboard state ultra-thin glass 11: Beveled cut section

[0037] 2: Coating 3: Infrared laser

[0038] 4: Ultraviolet laser; 5: Unit-level ultrathin glass Detailed Implementation

[0039] The present invention will now be described in detail with reference to the accompanying drawings.

[0040] like Figure 1As shown, the method for removing coatings, cutting glass, and post-processing using a laser according to the present invention includes: step (S1), coating one or both sides of a base plate ultrathin glass 1 with a coating liquid for preventing contact with chemical substances to perform selective chemical treatment; step (S2), drying the coating liquid to form a coating film 2 on one or both sides of the base plate ultrathin glass 1; step (S3), irradiating the coating film 2 formed on any side of the base plate ultrathin glass 1 with a laser beam along a predetermined cutting line of the base plate ultrathin glass 1 to remove a portion of the coating film, and irradiating the surface of the base plate ultrathin glass 1 exposed to the outside by the coating removal portion A through the coating film 2 to cut the base plate ultrathin glass 1. The process involves cutting the mother-plate ultrathin glass 1 into unit-level ultrathin glass 5 for use in electrical and electronic products; step (S4) involves selectively chemically treating the cut unit-level ultrathin glass 5 to heal the laser-cut surface of the unit-level ultrathin glass 5, thereby removing thermal damage and defects around the cut surface of the unit-level ultrathin glass 5 that occurred during the laser cutting process; step (S5) involves cleaning the unit-level ultrathin glass 5 and then completely removing the coating 2 formed on the surface of the unit-level ultrathin glass 5; and step (S6) involves cleaning the unit-level ultrathin glass 5 after removing all the coating 2 and then chemically healing the surface of the unit-level ultrathin glass 5 to remove any defects or blemishes on the surface of the unit-level ultrathin glass 5 after all the coating 2 has been removed. The thickness of the mother-plate ultrathin glass 1 and the unit-level ultrathin glass 5 is less than 100 μm.

[0041] The thickness of the coating 2 formed on any side of the ultrathin glass 1 in the mother plate state is 1 μm to 30 μm.

[0042] The ultra-thin glass 1 in the motherboard state is made of sodium alumino-silicate glass.

[0043] And, as Figure 1 As shown, the present invention also includes: cleaning and strengthening the unit-level ultrathin glass 5 after surface healing is completed.

[0044] like Figure 2As shown, step (S3) of irradiating a portion of the coating 2 formed on any side of the ultra-thin glass 1 in the motherboard state along a predetermined cutting line of the ultra-thin glass 1 in the motherboard state with a laser beam to remove (ablation) a portion of the coating 2, and then irradiating the surface of the ultra-thin glass 1 in the motherboard state exposed to the outside by the laser beam to cut the ultra-thin glass 1 in the motherboard state, thereby cutting the ultra-thin glass 1 in the motherboard state into unit-level ultra-thin glass 5 for use in electrical and electronic products, includes the following steps: when the coating 2 is removed... When the coating is formed only on one side of the ultra-thin glass 1 in the mother plate state, a laser beam (beam) output from an ultraviolet laser 4 that generates wavelengths below 400 nm is irradiated along the predetermined cutting line of the ultra-thin glass 1 in the mother plate state to remove the coating 2 along the predetermined cutting line of the ultra-thin glass 1 in the mother plate state, and a laser beam output from an infrared laser 3 that generates wavelengths above 1000 nm is irradiated on the ultra-thin glass 1 in the mother plate state exposed to the outside by the coating removal part A that has been removed by the coating 2 to cut the ultra-thin glass 1 in the mother plate state.

[0045] Step (S3) of irradiating a portion of the coating 2 formed on any side of the ultra-thin glass 1 in the motherboard state along a predetermined cutting line of the ultra-thin glass 1 in the motherboard state with a laser beam to remove it, and then irradiating the surface of the ultra-thin glass 1 in the motherboard state exposed to the outside by the coating removal portion A after the coating 2 has been removed with a laser beam to cut the ultra-thin glass 1 in the motherboard state, thereby cutting the ultra-thin glass 1 in the motherboard state into unit-level ultra-thin glass 5 for use in electrical and electronic products, includes the following steps: when the coating 2 is formed on both sides of the ultra-thin glass 1 in the motherboard state... A laser beam (beam) output from an ultraviolet laser 4 that generates wavelengths below 400 nm is irradiated along a predetermined cutting line of the motherboard ultrathin glass 1 onto the surface of a coating 2 formed on one side of the motherboard ultrathin glass 1 to remove a pair of coatings 2 facing each other in the thickness direction of the motherboard ultrathin glass 1 along the predetermined cutting line of the motherboard ultrathin glass 1. A laser beam output from an infrared laser 3 that generates wavelengths above 1000 nm is irradiated onto the motherboard ultrathin glass 1 exposed to the outside by the coating removal section A through which the coatings 2 have been removed to cut the motherboard ultrathin glass 1.

[0046] When the coating 2 is formed only on both sides of the ultra-thin glass 1 in the mother plate state, if the ultraviolet laser beam irradiates the coating 2 formed on either side, the ultraviolet laser beam passes through the stacked pair of coatings 2 and the ultra-thin glass 1 in the mother plate state sandwiched between the pair of coatings 2 in sequence, and the coatings 2 formed on both sides of the ultra-thin glass 1 in the mother plate state are removed by the ultraviolet laser beam.

[0047] The infrared laser 3 is a nanosecond infrared laser 3, a picosecond infrared laser 3, or a femtosecond infrared laser 3, and the infrared laser 3 outputs a Bessel beam.

[0048] The ultraviolet laser 4 is a nanosecond ultraviolet laser 4, a picosecond ultraviolet laser 4, or a femtosecond ultraviolet laser 4.

[0049] The infrared laser 3 that outputs a Bessel beam has a laser beam wavelength of 1020 nm to 1040 nm, a laser beam size of 0.8 μm to 1.8 μm, and a laser beam pulse duration of 3 ps to 12 ps.

[0050] Furthermore, the pulse repetition rate of the laser beam is 190 kHz to 210 kHz, and the pulse energy is 3 μJ to 42 μJ.

[0051] In step (S3), where a portion of the coating 2 formed on any side of the ultrathin glass 1 in the motherboard state is ablated by irradiating a laser beam along a predetermined cutting line of the ultrathin glass 1 in the motherboard state, and the surface of the ultrathin glass 1 in the motherboard state exposed to the outside by irradiating the coating removal portion A through the coating 2 to cut the ultrathin glass 1 in the motherboard state to be cut into unit-level ultrathin glass 5 for use in electrical and electronic products, an ultraviolet laser 4 is used as the laser for removing the coating 2, and an infrared laser 3 is used as the laser for cutting the ultrathin glass 1 in the motherboard state. The infrared laser 3 outputs a Bessel beam. A scanner is installed on the ultraviolet laser 4 so that the cutting efficiency of the coating 2 can be improved by freely adjusting the position of the laser beam irradiated on the coating 2.

[0052] When a femtosecond ultraviolet laser scanner is used as the scanner, the laser beam wavelength of the femtosecond ultraviolet laser 4 is 250nm to 360nm, the laser beam size output from the femtosecond ultraviolet laser scanner is 5um to 50um, and the laser beam spot overlap rate output from the femtosecond ultraviolet laser scanner is 10% to 99%.

[0053] Furthermore, the moving speed of the femtosecond ultraviolet laser 4 is 500 mm / s to 5000 mm / s, and the pulse repetition rate of the laser beam output from the femtosecond ultraviolet laser 4 is 400 kHz or 800 kHz.

[0054] The coating solution is a solution with an ultraviolet absorption rate of more than 10% in the ultraviolet wavelength range below 400 nm and an infrared absorption rate of less than 1% in the infrared wavelength range above 1000 nm, selected from acrylic acid solution, polyethylene resin, polypropylene resin, polyvinyl chloride resin or polystyrene resin.

[0055] In the step (S1) of coating one or both sides of the ultra-thin glass 1 in the motherboard state with a coating liquid to prevent contact with chemical substances for selective chemical treatment, when the coating liquid is applied to one side of the ultra-thin glass 1 in the motherboard state, a slot die coating, a spray coating, an inkjet coating, a bar coating, or a screen printing method can be used. When the coating liquid is applied to both sides, a spray coating or a dip coating method can be used.

[0056] In step (S1), when coating one or both sides of the ultra-thin glass 1 in the motherboard state with a coating liquid to prevent contact with chemical substances for selective chemical treatment, the coating liquid can be applied to both sides of the ultra-thin glass 1 in the motherboard state by spraying, or by immersing the ultra-thin glass 1 in the coating liquid for coating on both sides, or by coating one side of the ultra-thin glass 1 first, then flipping the ultra-thin glass 1 in the motherboard state and coating the other side.

[0057] In step (S2) of drying the coating liquid to form a coating film 2 on one or both sides of the ultrathin glass 1 in the mother plate state, the drying method of the coating liquid can use infrared lamps, hot air generators, hot plates, ovens, etc., and a cluster type drying device can be used in an inline type drying device.

[0058] like Figure 4As shown, in step (S4) of selectively chemically treating the cut surface of the unit-level ultrathin glass 5 to heal the laser-cut surface of the unit-level ultrathin glass 5 and remove the thermal damage and defects around the cut surface of the unit-level ultrathin glass 5 that occurred during the laser cutting process, a beveled cutting portion 11 is formed at the right-angle corner of the unit-level ultrathin glass 5 that is in contact with the coating 2 by a healing solution. The lateral width W of the beveled cutting portion 11 is 3 μm to less than 500 μm, and the height H of the beveled cutting portion 11 is more than 3 μm but does not exceed 50% of the thickness of the unit-level ultrathin glass 5.

[0059] The unit-level ultrathin glass 5 is immersed in a healing solution to be healed, the healing solution containing ammonium difluoride, sulfuric acid, nitric acid, water and additives.

[0060] The additive is a surfactant used to improve healing performance, which increases the uniformity of healing by reducing surface tension.

[0061] The healing solution contains 0.5 to 0.9% by weight ammonium difluoride, 3 to 15% by weight sulfuric acid, 1 to 10% by weight nitric acid, 80 to 90% by weight water, and 0.01 to 0.1% by weight additives.

[0062] The surfactant may be a compound represented by the following chemical formula 1:

[0063] [Chemical Formula 1]

[0064] R1-OSO3 - HA +

[0065] Wherein, R1 is 4,8,12-triproplypentadecane, and A is triethanolamine.

[0066] In step (S5) after cleaning the unit-level ultrathin glass 5, the coating 2 formed on the surface of the unit-level ultrathin glass 5 is completely removed. The unit-level ultrathin glass 5 coated with the coating 2 is immersed in the coating removal solution to melt and remove the coating 2.

[0067] The coating removal solution is an alkaline aqueous solution, and potassium hydroxide (KOH) can be used, wherein the temperature of the potassium hydroxide (KOH) is above 25 degrees Celsius.

[0068] However, in order to remove traces of coating 2 that are present on the surface of the unit-level ultrathin glass 1 due to the adhesion of some coating 2, an additional cleaning process can be performed after removing coating 2.

[0069] In the step of strengthening the unit-level ultrathin glass 5 after cleaning the surface-healed glass, the cleaning solution for the surface-healed unit-level ultrathin glass 5 includes a potassium hydroxide (KOH) or sodium hydroxide (NaOH) solution and pure deionized water with added surfactant, and the pH of the cleaning solution is above 10.

[0070] In the step of strengthening the unit-level ultrathin glass 5 after cleaning the surface-healed glass, the strengthening liquid used to strengthen the unit-level ultrathin glass 5 is a potassium nitrate melt.

[0071] The step of cleaning and strengthening the unit-level ultrathin glass 5 after surface healing includes the following steps: preheating the cleaned unit-level ultrathin glass 5 to a range of 200°C to 400°C; immersing the preheated unit-level ultrathin glass 5 in a strengthening liquid maintained at 370°C to 470°C for strengthening; and slowly cooling the unit-level ultrathin glass 5 to room temperature after removing it from the strengthening liquid.

[0072] The method according to the invention, which consists of this process of using laser to remove coating, cut glass and post-processing, can reduce the manufacturing cost of unit-level ultrathin glass by simplifying the manufacturing process when manufacturing unit-level ultrathin glass 5 for use in various electrical and electronic products.

[0073] Furthermore, the present invention can improve production efficiency by selectively chemically removing thermal damage around the glass cut surface caused by the laser beam during laser cutting and coating, thereby improving the durability of the finished unit-level ultrathin glass and reducing defects.

Claims

1. A method for removing coatings, cutting glass, and post-processing using a laser, characterized in that, include: Step (S1): Coating both sides of the ultrathin glass (1) in the motherboard state with a coating liquid to prevent contact with chemicals for selective chemical treatment; Step (S2) involves drying the coating liquid to form a coating film (2) on both sides of the ultrathin glass (1) in the mother plate state. In step (S3), a laser beam is irradiated along the predetermined cutting line of the ultra-thin glass (1) on both sides of the coating (2) formed on the mother plate state to remove a portion of the coating. The surface of the ultra-thin glass (1) exposed to the outside by the coating removal part (A) after the coating (2) is removed is irradiated with a laser beam to cut the ultra-thin glass (1) in the mother plate state, thereby cutting the ultra-thin glass (1) in the mother plate state into unit-level ultra-thin glass (5) for use in electrical and electronic products. Step (S3) specifically includes the following steps: A laser beam output from an ultraviolet laser (4) producing wavelengths below 400 nm is irradiated along the predetermined cutting line of the mother plate state ultrathin glass (1) onto the surface of a coating (2) formed on one side of the mother plate state ultrathin glass (1) to remove a pair of coatings (2) facing each other in the thickness direction of the mother plate state ultrathin glass (1) along the predetermined cutting line of the mother plate state ultrathin glass (1), and a laser beam output from an infrared laser (3) producing wavelengths above 1000 nm is irradiated onto the mother plate state ultrathin glass (1) exposed to the outside by the coating removal part (A) through the coating (2) to cut the mother plate state ultrathin glass (1); In step (S3), an ultraviolet laser (4) is used as the laser for removing the coating (2). An infrared laser (3) is used as the laser for cutting the ultrathin glass (1) in the mother plate state. The infrared laser (3) outputs a Bessel beam. A scanner is installed on the ultraviolet laser (4) so ​​that the cutting efficiency of the coating (2) can be improved by freely adjusting the position of the laser beam irradiated on the coating (2); The thickness of the motherboard ultra-thin glass (1) and the unit-level ultra-thin glass (5) is less than 100 μm; The thickness of the coating (2) formed on any side of the ultrathin glass (1) in the mother plate state is 1 μm to 30 μm; The coating solution is a solution with an ultraviolet absorption rate of more than 10% in the ultraviolet wavelength range below 400 nm and an infrared absorption rate of less than 1% in the infrared wavelength range above 1000 nm, selected from acrylic acid solution, polyethylene resin, polypropylene resin, polyvinyl chloride resin or polystyrene resin. The infrared laser (3) is a nanosecond infrared laser (3), a picosecond infrared laser (3), or a femtosecond infrared laser (3). The infrared laser (3) outputs a Bessel beam. The wavelength of the laser beam of the infrared laser (3) that outputs the Bessel beam is 1020nm to 1040nm, and the size of the laser beam is 0.8um to 1.8um. ​​The ultraviolet laser (4) is a femtosecond ultraviolet laser (4). The wavelength of the laser beam of the femtosecond ultraviolet laser (4) is 250nm to 360nm. The size of the laser beam output from the femtosecond ultraviolet laser scanner is 5um to 50um, and the spot overlap rate of the laser beam output from the femtosecond ultraviolet laser scanner is 10% to 99%. Step (S4) involves selectively chemically treating the cut unit-level ultrathin glass (5) to heal the laser-cut surface of the unit-level ultrathin glass (5) in order to remove thermal damage and defects around the cut surface of the unit-level ultrathin glass (5) that occurred during the laser cutting process. The step (S4) further includes: At the right-angled corners of the unit-level ultrathin glass (5) that are in contact with the coating (2), a beveled cut (11) is formed by selective chemical treatment. The transverse width (W) of the beveled cut portion (11) is 3 μm to less than 500 μm. The height (H) of the beveled cut section (11) is 3 μm or more, but does not exceed 50% of the thickness of the unit-level ultrathin glass (5); Step (S5): After cleaning the unit-level ultrathin glass, the coating (2) formed on the surface of the unit-level ultrathin glass (5) is completely removed; and Step (S6) involves cleaning the unit-level ultrathin glass (5) after removing all coating (2) and then chemically healing the surface of the unit-level ultrathin glass (5) to remove defects or flaws on the surface of the unit-level ultrathin glass (5) after all coating (2) has been removed.

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