CN113453444B

CN113453444B - Method for manufacturing insulating paint protection film of PCB (printed circuit board)

Info

Publication number: CN113453444B
Application number: CN202110730571.0A
Authority: CN
Inventors: 南涛
Original assignee: Southwest Electronic Technology Institute No 10 Institute of Cetc
Current assignee: Southwest Electronic Technology Institute No 10 Institute of Cetc
Priority date: 2021-06-30
Filing date: 2021-06-30
Publication date: 2023-09-12
Anticipated expiration: 2041-06-30
Also published as: CN113453444A

Abstract

The method for manufacturing the insulating paint protective film of the PCB disclosed by the invention has the advantages of high quality and quick response. The invention is realized by the following technical scheme: firstly, selecting a protective film with release paper, and adding a fluorine polymer into the protective film; according to the size and the number of the positions to be protected of the workpiece, calculating the area of protective tape paper to be cut, applying a protective film on the surface of a PCB product, then effectively pasting isolating paper to all the positions to be protected, coating a silicone rubber common film layer on a fluoropolymer PET carrier protective film sheet substrate film, cutting lines by using a laser engraving machine, rapidly cutting the shape on the protective film after focusing according to the design or the protection shape of a product design model diagram, engraving any design pattern, finally stripping the protective film, removing the isolating paper, and pasting the protective film at the position where the workpiece is suitable to be protected, thus completing the protection work.

Description

Method for manufacturing insulating paint protection film of PCB (printed circuit board)

Technical Field

The invention relates to the field of circuit boards, in particular to a method for manufacturing a painted protective film, which is used for improving the protective film capability of printed circuit board PCB (Printed Circuit Board) products before painting.

Background

In the composition of electronic products, the protective film is an indispensable part, after the surface treatment of metal and nonmetal workpieces in the industries of electronics, appliances and the like, the local protection of the products is required before painting, and two main tasks of green paint on the board surface of the printed circuit board PCB (Printed Circuit Board) are welding prevention and wire protection, wherein the wire protection function is generally presented by the enameled wire covered by the insulating film. The quality of the PCB green paint is directly related to downstream organization due to the shipment of the PCB, and the quality of the PCB green paint has profound influence on the final product. Especially, the novel BGA and CSP are not only required to stop bubbles, but also required to be the thickness of green paint on the PCB surface. Therefore, the circuit board can prevent the wires from being damaged by external pollutants in various severe environments, and the Reliability is not critical. The formed protective film is used for protection, so that the speed is high and the effect is excellent. However, the protective film is a very tedious process from production to material processing, and needs to be manufactured by different multiple process technologies. When the green paint thickness of the PCB surface is insufficient, particularly for a power line with larger line width and larger current, the PCB surface is easy to corrode at a high speed in a bad environment and in power-on work. The power line is easy to be bitten by foreign matters in severe external environment through green paint on the PCB surface of the printed circuit board with insufficient thickness after being assembled into a finished product for half a year. The method commonly used at present is a method of sticking after manual tape cutting. However, the method has lower efficiency, and particularly has high protection difficulty on the position which is difficult to protect manually in the groove, so that the protection effect is poor. In the manual tape cutting and pasting protection method, most plastic films (such as a hydrocarbon film) are nonpolar polymers, the surface tension is low and is generally 29-30 mN/m, and in theory, if the surface tension of an object is lower than 33mN/m, the known ink and adhesive can not be firmly adhered on the surface. During the printing process, the protective film material can be contacted with the printing roller, so that the surface of the material is scratched due to friction. The die cutting process is easy to cause scratches due to the fact that the material pressing roller rotates unevenly, and most commonly, the material and the material pressing roller rotate to generate scratches caused by relative sliding. The rotation of the press roll is checked before die cutting, ensuring that the rotation of the press roll in contact with the material is flexible. In addition, the protective film can be scratched by foreign matters on the pressing roller, and the punch mark can also appear. In the process of printing the protective film, the definition and firmness of printed images and texts are controlled, and qualified protective film products require accurate and clear characters and clear edges of the images. The smaller the word, the more difficult it is to control sharpness. In addition, when the ink layer thickness is too thick, the phenomenon of ink collapse occurs. The solder mask paint is also called solder mask ink, is a protective layer of the PCB, can protect copper wires and also can prevent parts from being welded to incorrect places, and in addition, the solder mask can also play a role in improving line insulation, oxidation resistance and attractiveness. The green paint of the circuit board (PCB) is easy to scratch and fall off and erode by green oil solvent, and is insufficient to bear the test of a tin furnace, especially, the green paint is not as high in hardness as the normal temperature environment under the high temperature condition, at the moment, the green paint surface of the circuit board is easy to scratch and fall off due to any external impact, so that the service life of a film layer is shortened, and the repair rate of the PCB is increased. The circuit board (PCB) bursts before green paint coating or when being stored due to moisture absorption, the volume of water vapor expands by nearly three hundred times when being heated and gasified, the temperature rises instantly, and the green paint is softened, so that the green paint is easy to peel off. Such problems may occur in the tin spraying process of circuit board manufacture, and may also occur in the assembly processes such as wave soldering, reflow soldering, etc. In order to cut the leveling of the adhesive tape and accelerate the packaging efficiency, the prior art commonly uses a manual adhesive tape cutting and then pasting protection method, the method uses an adhesive tape cutter, firstly, the adhesive surface of the adhesive tape is upwards, and the adhesive tape passes through the rubber roller and the metal bracket; then the rubber roller is pressed against the adhesive tape, so that the adhesive tape and the roller keep a balanced state; when in use, the mouth of the tooth is required to be tilted upwards, so that the adhesive tape is not damaged; finally, the adhesive tape cutter is held tightly, and the inner adhesive tape is cut off downwards. Since the tapes are all tacky, care must be taken when using the tape cutter.

Disclosure of Invention

The invention aims at overcoming the defects of the manual adhesive tape post-cutting pasting protection method, and provides a method for manufacturing a painting protection film with high quality and quick response.

In order to achieve the above object of the present invention, the present invention provides a method for manufacturing an insulating paint protective film for a PCB circuit board, which is characterized by comprising the steps of: firstly, selecting a protective film with release paper, and adding a fluorine polymer into the protective film; calculating the area of protective tape paper to be cut according to the size and the number of the positions to be protected of the workpiece, attaching a protective film to the surface of a Printed Circuit Board (PCB), then effectively attaching isolating paper to all the positions to be protected, and coating a silicone rubber co-film layer on a fluoropolymer PET carrier substrate protective film sheet; the adopted laser engraving processing method is to cut lines by using a laser engraving machine, the laser engraving machine cuts the shape on the protective adhesive film rapidly after focusing according to the design or the protection shape of the design model drawing of the leading-in product, and to engrave any design pattern, finally, the isolation paper is removed, the protective sheet is peeled off, and the protective film is stuck on the position where the workpiece is properly protected, thus the protection work can be completed.

Compared with the prior art, the invention has the following beneficial effects:

high quality and quick effect. The invention selects a protective film with isolating paper, and adds fluorine polymer into the protective film; because the fluoropolymer has excellent self-flame retardance, self-cleaning performance, corrosion resistance, high temperature resistance and other performances, the film layer can be closely contacted with the surface of an adherend and can flow into a groove on the surface of the adherend as much as possible, so that the effective contact area is increased, the film layer has good adhesive force to various circuit boards, and the film layer has good temperature resistance and keeps good cold and hot ageing performance within the (-60 ℃ to 200 ℃); has higher stripping resistance. The laser engraving machine is used for cutting lines, the edge of the cut adhesive tape paper is neat, the shape is standard, and residues of the traditional manual cutting adhesive tape are avoided. Meanwhile, the laser engraving machine can realize cutting of a large number of protective films, the production efficiency of batch products is improved quickly, and after a program is stored, the laser engraving machine can realize multiple times of manufacturing. The method is applied to the surface of the product, and can realize excellent appearance quality such as appearance flatness and the like.

According to the invention, the area of the protective tape paper to be cut is calculated according to the size and the number of the positions to be protected of the workpiece, then the protective film is attached to the surface of a PCB product, the PET carrier protective film sheet substrate film is coated with the silicone rubber common film layer, the adhesive tape paper is made of the PET substrate film coated with the silicone rubber, and the silicone rubber layer is gradually reduced from the middle part to the two sides, so that the protective film does not have the problem of wrinkling during brushing. Can effectively play a role in protecting the materials from being stained and scratched in the processes of storage, transportation and processing. The thickness is 60-80 um, the adhesion to steel is 30-40N/100 mm, and the steel can resist 120 ℃ high temperature. The film layer is easy to tear off and has no residue. The weather resistance and the flame retardance are good, and the surface is not polluted after being stripped at high temperature.

The invention can be used for rapidly protecting the workpiece before painting, and has no influence on the surface quality of the subsequent painting. The protective film is used for protecting the surface of metal and nonmetal workpieces in the industries of electronics, electric appliances and the like, and particularly has excellent effect on the positions which are difficult to protect manually in the grooves and protected by using the formed protective film.

Detailed Description

According to the invention, a Printed Circuit Board (PCB) product protection method is adopted, firstly, a protection adhesive film with release paper is selected and used, and a fluorine polymer is added into the protection film; calculating the area of protective tape paper to be cut according to the size and the number of the positions to be protected of the workpiece, attaching a protective film to the surface of a Printed Circuit Board (PCB), then effectively attaching isolating paper to all the positions to be protected, and coating a silicone rubber co-film layer on a fluoropolymer PET carrier substrate protective film sheet; the adopted laser engraving processing method is to cut lines by using a laser engraving machine, the laser engraving machine cuts the shape on the protective adhesive film rapidly after focusing according to the design or the protection shape of the design model drawing of the leading-in product, and to engrave any design pattern, finally, the isolation paper is removed, the protective sheet is peeled off, and the protective film is stuck on the position where the workpiece is properly protected, thus the protection work can be completed.

The PET substrate film is coated with the silicone rubber co-film layer with the thickness of 60-80 um, and the adhesion force to steel is 30-40N/100 mm.

The laser carving treatment method is to design pattern on the laser carving machine or to introduce product design pattern into the laser carving machine based on the shape of the PCB product to be protected, and to start the laser cutting machine to cut the shape on the protecting film after focusing.

The PCB product protecting method includes adhering isolating paper to the surface, pit, etc. and separating the protecting film from the isolating paper with tweezers, etc.

The above examples illustrate only a few embodiments of the invention, which are described in detail and are not to be construed as limiting the scope of the invention. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the invention, which are all within the scope of the invention. Accordingly, the scope of protection of the present invention is to be determined by the appended claims.

Claims

1. The method for manufacturing the PCB insulating paint protection film is characterized by comprising the following steps of: adopting a Printed Circuit Board (PCB) product protection method, firstly selecting a protection adhesive film with release paper, and adding a fluorine polymer into the protection adhesive film; calculating the area of a protective adhesive film to be cut according to the size and the number of the positions to be protected of the workpiece, applying the protective adhesive film to the surface of a Printed Circuit Board (PCB) product, and effectively adhering the protective adhesive film to all the positions to be protected; the base material of the protective adhesive film added with the fluorine polymer is a PET carrier, and a silicone rubber co-film layer is coated on the protective adhesive film; the adopted laser engraving processing method is to cut lines by using a laser engraving machine, and the laser engraving machine cuts the shape on the protective adhesive film rapidly after focusing according to the design or the protection shape of the design model drawing of the leading-in product, so as to engrave any design pattern; finally, removing the isolation paper carried by the protective adhesive film, stripping the protective adhesive film, and attaching the protective adhesive film to a position where a workpiece is properly protected to finish the protection work;

the protective adhesive film takes a PET carrier as a base material, the thickness of the protective adhesive film after the fluoropolymer is added and the silicone rubber co-film layer is coated is 60-80 um, and the adhesive force to steel is 30-40N/100 mm;

the method for processing the laser engraving is to perform pattern design on a laser engraving machine or to introduce a product design model diagram according to the shape of the position to be protected of the PCB product, then start a laser cutting machine, and quickly cut the shape on a protective adhesive film after focusing;

the protection method of the PCB product comprises the following steps: the method comprises the steps of effectively pasting a protective adhesive film on all positions to be protected, and pasting the positions to be protected in alignment, wherein the positions to be protected comprise plane positions or pit positions; after the laser engraving machine engraves the design pattern, the protective adhesive film is separated from the release paper by using a tweezer tool.