阅读说明：本技术 一种印制电路板阻焊桥制作方法 (Method for manufacturing solder mask bridge of printed circuit board ) 是由 李清华 张仁军 牟玉贵 胡志强 杨海军 于 2021-09-07 设计创作，主要内容包括：本申请提供一种印制电路板阻焊桥制作方法,包括步骤：提供覆铜板,对所述覆铜板进行前处理,前处理包括酸洗、磨板、喷砂,并采用清洁装置同步完成水洗及烘干处理；提供阻焊干膜,所述阻焊干膜由依次设置的保护膜、光致涂覆膜和聚酯膜构成；将所述阻焊干膜贴附在所述覆铜板表面；贴附前去除所述保护膜,使所述光致涂覆膜与所述覆铜板表面接触；提供菲林片,将所述菲林片对位贴合于所述阻焊干膜的表面进行曝光；揭除所述聚酯膜、显影、固化。可使阻焊桥宽度最小可做到2mil,工艺环保、流程短、效率高；对覆铜板采用直立式清洁方式,可有效提高清洁质量,同时提高阻焊干膜的粘接效果,进一步保证印制电路板的成品质量。(The application provides a method for manufacturing a solder mask bridge of a printed circuit board, which comprises the following steps: providing a copper-clad plate, and carrying out pretreatment on the copper-clad plate, wherein the pretreatment comprises pickling, plate grinding and sand blasting, and a cleaning device is adopted to synchronously complete washing and drying treatment; providing a solder resist dry film, wherein the solder resist dry film is composed of a protective film, a photo-induced coating film and a polyester film which are arranged in sequence; attaching the solder resist dry film to the surface of the copper clad plate; removing the protective film before attaching to enable the photoinduced coating film to be in contact with the surface of the copper-clad plate; providing a film, and attaching the film to the surface of the solder resist dry film in an aligned manner for exposure; and removing the polyester film, developing and curing. The minimum width of the solder resisting bridge can be 2mil, the process is environment-friendly, the flow is short, and the efficiency is high; the copper-clad plate is cleaned in a vertical type mode, so that the cleaning quality can be effectively improved, the bonding effect of the solder-resisting dry film is improved, and the finished product quality of the printed circuit board is further ensured.)

1. A method for manufacturing a solder mask bridge of a printed circuit board is characterized by comprising the following steps:

providing a copper-clad plate, and carrying out pretreatment on the copper-clad plate, wherein the pretreatment comprises pickling, plate grinding and sand blasting, and a cleaning device is adopted to synchronously complete washing and drying treatment;

providing a solder resist dry film, wherein the solder resist dry film is composed of a protective film, a photo-induced coating film and a polyester film which are arranged in sequence;

attaching the solder resist dry film to the surface of the copper clad plate; removing the protective film before attaching to enable the photoinduced coating film to be in contact with the surface of the copper-clad plate;

providing a film, and attaching the film to the surface of the solder resist dry film in an aligned manner for exposure;

removing the polyester film;

developing;

and (5) curing.

2. The method for manufacturing the solder mask bridge of the printed circuit board as claimed in claim 1, wherein the dry solder mask film is attached to the surface of the copper clad plate by means of vacuum lamination; the temperature of the vacuum film pasting is 60-70 ℃, the vacuum time is more than 15s, and the film pasting time is 15-30 s.

3. The method for manufacturing the solder mask bridge of the printed circuit board as claimed in claim 1, wherein the thickness of the dry film of the solder mask is 20-60 μm, wherein the thickness of the protective film is 20-30 μm, the thickness of the photo-induced coating film is 10-100 μm, and the thickness of the polyester film is 20-30 μm.

4. The method as claimed in claim 1, wherein the photo-induced coating film is mainly composed of acrylic resin, and is coated on the surface of the polyester film by spraying; the protective film is made of polyethylene; the method is as follows.

5. The method for manufacturing the solder mask bridge of the printed circuit board as claimed in claim 1, wherein in the curing step, an oven is adopted, the temperature is controlled to be 150 ℃ to 160 ℃, and the curing time is 60min to 70 min.

6. The method for manufacturing the solder mask bridge of the printed circuit board according to claim 1, wherein the copper-clad plate is in a vertical state when being cleaned by the cleaning device.

Technical Field

The invention belongs to the technical field of printed circuit board production, and particularly relates to a method for manufacturing a solder mask bridge of a printed circuit board.

Background

The conventional solder resist of the printed circuit board is formed by mixing a liquid main agent and a diluent, printing the mixture on a processed clean printed board in a gauze mode, baking the solder resist on the board surface, and then forming a solder resist bridge at a position needing to be welded in an exposure and development mode by using a solder resist film. The processing of the mode has limitations due to the resistance welding performance and the processing process, and the minimum width of the resistance welding bridge can only achieve 4 mils. With the density and miniaturization of printed circuit boards, the technology cannot meet the requirements for positions with small surface-mount spacing.

Disclosure of Invention

In order to solve the defects of the prior art, the invention provides a method for manufacturing a solder mask bridge of a printed circuit board, which adopts a processing mode of a solder mask dry film to minimize the width of the solder mask bridge and can achieve 2mil, and has the advantages of environment-friendly process, short flow and high efficiency; and the copper-clad plate is cleaned in a vertical type manner, so that the cleaning quality can be effectively improved, the bonding effect of the solder-resisting dry film is improved, and the finished product quality of the printed circuit board is further ensured.

In order to realize the purpose of the invention, the following scheme is adopted:

a method for manufacturing a solder mask bridge of a printed circuit board comprises the following steps:

providing a copper-clad plate, and carrying out pretreatment on the copper-clad plate, wherein the pretreatment comprises pickling, plate grinding and sand blasting, and a cleaning device is adopted to synchronously complete washing and drying treatment;

providing a solder resist dry film, wherein the solder resist dry film is composed of a protective film, a photo-induced coating film and a polyester film which are arranged in sequence;

attaching the solder resist dry film to the surface of the copper clad plate; removing the protective film before attaching to enable the photoinduced coating film to be in contact with the surface of the copper-clad plate;

providing a film, and attaching the film to the surface of the solder resist dry film in an aligned manner for exposure;

removing the polyester film;

developing;

and (5) curing.

Further, attaching the solder resist dry film to the surface of the copper clad plate in a vacuum film attaching mode; the temperature of the vacuum film pasting is 60-70 ℃, the vacuum time is more than 15s, and the film pasting time is 15-30 s.

Further, the thickness of the solder resist dry film is 20-60 μm, wherein the thickness of the protective film is 20-30 μm, the thickness of the photo-induced coating film is 10-100 μm, and the thickness of the polyester film is 20-30 μm.

Further, the photo-induced coating film is mainly composed of acrylic resin, and is coated on the surface of the polyester film in a spraying mode; the protective film is made of polyethylene; the method is as follows.

Further, in the curing step, an oven is adopted, the temperature is controlled to be 150-160 ℃, and the curing time is 60-70 min.

Further, the copper-clad plate is in a vertical state when being cleaned by the cleaning device.

The invention has the beneficial effects that:

1. this application utilizes to hinder the mode preparation printed circuit board of hindering dry film and copper-clad plate laminating and hinders the solder bridge, makes the minimum width that hinders the solder bridge can reach 2 mils, is favorable to the further miniaturization of circuit board. Compared with the prior art, the method has the advantages of environmental protection, shorter flow and higher efficiency.

2. The special cleaning device is adopted to synchronously complete washing and drying treatment, and the cleaning device is used for cleaning, drying and outputting the copper-clad plate in an upright mode, so that the copper-clad plate cleaning device has better cleaning effect and higher cleaning efficiency.

Drawings

The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure.

Figure 1 shows a process flow diagram of the present application.

Figure 2 shows an external view of the cleaning device.

Fig. 3 shows an internal configuration diagram of the cleaning apparatus.

Fig. 4 shows a cross-sectional view of the conveyor roller.

Fig. 5 shows a cross-sectional view of the conveying roller when conveying the copper-clad plate.

FIG. 6 is a diagram showing the structure and connection of the water spray pipe, the transverse gas blowing pipe and the limiting groove.

Fig. 7 shows an enlarged view at a in fig. 6.

Fig. 8 shows a schematic structural diagram of the material frame.

Fig. 9 shows an enlarged view at B in fig. 8.

Fig. 10 shows a state diagram of the material frame in use.

The labels in the figure are: the device comprises a cleaning device-10, a cleaning station-20, a water spray pipe-21, a blow-drying station-30, a transverse air blow pipe-31, a longitudinal air blow pipe-32, a drying station-40, a conveying rail-50, a conveying roller-51, a rotating shaft-511, a disc-512, a rubber sleeve-513, a V-shaped groove-5131, a limiting groove-60, a groove-shaped steel-61, a cylindrical roller-62, a clamping ring-63, an opening-631, a locking screw-64, an output rail-70, a material frame-80, a first roller-81 and a second roller-82.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the following detailed description of the embodiments of the present invention is provided with reference to the accompanying drawings, but the described embodiments of the present invention are a part of the embodiments of the present invention, not all of the embodiments of the present invention.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings or orientations or positional relationships that the products of the present invention are usually placed in when used, and are only for convenience of describing the present invention and simplifying the description. The terms "first," "second," and the like are used solely to distinguish one from another and are not to be construed as indicating or implying relative importance. The terms "parallel", "perpendicular", etc. do not require that the components be absolutely parallel or perpendicular, but may be slightly inclined.

In the description of the present invention, it should also be noted that, unless otherwise explicitly specified or limited, the terms "disposed," "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; either directly or indirectly through intervening media, or through both elements. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

Example 1

As shown in fig. 1, a method for manufacturing a solder mask bridge of a printed circuit board comprises the following steps:

and S1, providing a copper-clad plate, carrying out pretreatment on the copper-clad plate, wherein the pretreatment comprises acid washing, plate grinding and sand blasting, and the cleaning device is adopted to synchronously complete washing and drying treatment so as to improve the efficiency and effectively avoid the pollution of the copper-clad plate before drying.

And S2, providing a solder resist dry film, wherein the solder resist dry film is composed of a protective film, a photo-coating film and a polyester film which are arranged in sequence.

S3, attaching the solder resist dry film to the surface of the copper clad laminate; and removing the protective film before attaching to enable the photoinduced coating film to be in contact with the surface of the copper-clad plate.

And S4, providing a film, and attaching the film to the surface of the solder resist dry film in an alignment manner for exposure. The number of exposure steps can be 9-11, and the exposure energy can be 200-600 mj. If the exposure parameter is lower than the lower limit, poor exposure can occur, the small part of the bonding pad cannot be formed, and if the exposure parameter exceeds the upper limit, overexposure is performed, so that incomplete development is caused. The number of exposure steps can be 10, and the exposure energy can be 300-500 mj.

And removing the polyester film.

And S5, developing. The developing time can be 60-100 s. If the development time is outside the range.

And S6, curing.

In this example, the polyester film is a support supporting the photo-coating film and is applied to form a film. The polyester film is removed after exposure and before development, and prevents oxygen from diffusing into the resist layer during exposure, destroying radicals, and causing a decrease in sensitivity. The protective film is covered on the photo-induced coating film, dirt such as dust is prevented from being adhered to the dry film, and mutual adhesion between each layer of resist film is avoided when the film is rolled. The photo-induced coating film is a main body of a dry film, and the main component can be acrylic resin which is used for replacing a novel material of the existing solder resist process ink. May be a negative photosensitive material.

The dry film photoresist is prepared through coating pre-compounded photosensitive glue onto polyester film in a high precision coater, drying in a drying tunnel, cooling, coating protecting polyethylene film and winding on a roller core.

Preferably, the solder resist dry film is attached to the surface of the copper-clad plate in a vacuum film pasting mode so as to avoid generating bubbles; compared with the traditional film pasting mode, no scraper or roller is needed to apply pressure to the solder resist dry film, so that the photo-induced coating film is prevented from being thinned; the temperature of the vacuum film pasting is 60-70 ℃, the vacuum time is more than 15s, and the film pasting time is 15-30 s.

If the control temperature is lower than 60 ℃, the film is not firm, the binding force is poor, and if the control temperature is higher than 70 ℃, the dry film is excessively crosslinked, the binding force is also influenced. Alternatively, the control temperature may be 61-68 ℃.

The vacuum time can be 15-30 s. If the vacuum time is less than 15s, bubbles can be generated between the dry film and the copper surface; if the vacuum time exceeds 30 seconds, cost and efficiency are wasted because the vacuum has been reached. Here, the film pasting is completed in a vacuum chamber, and the vacuum time refers to the time of vacuumizing before the film pasting so as to enable the vacuum degree in the vacuum chamber to reach the requirement, and then the film pasting is performed.

The film-attaching time may be 15 seconds or more, for example, 15 to 30 seconds. If the film sticking time is less than 15s, the film sticking is not firm, and the bonding force is poor; if the film pasting time exceeds 30s, the dry film can be excessively crosslinked, and the dry film becomes thin.

The film sticking pressure can be 0.3-0.8 Kg/cm 2. If the pressure of the film is lower than 0.3Kg/cm2, the film is not firm and the bonding force is poor; if the pressure of the film patch exceeds 0.8Kg/cm2, dry film access is caused. The film sticking pressure can be 0.4-0.7 Kg/cm 2. The film sticking pressure can be 0.5-0.6 Kg/cm 2.

The thickness of the film copper can be 18-105 μm. The film copper thickness refers to the thickness of the substrate copper which can be processed by the solder resist dry film, and if the film copper thickness exceeds 105 μm, the film copper thickness exceeds the dry film processing capacity and cannot cover the circuit. The thickness of the film copper can be 20-95 μm. The thickness of the film copper can be 40-55 μm.

Preferably, the thickness of the dry film solder resist is 20-60 μm, wherein the thickness of the protective film is 20-30 μm, the thickness of the photo-induced coating film is 10-100 μm, and the thickness of the polyester film is 20-30 μm. The thickness of the solder resist dry film can be 20-60 mu m. If the dry film thickness of the solder resist is less than 20 μm, it may result in failure to apply wiring lines. If the dry film thickness of the solder resist exceeds 60 μm, excessive flow of the dry film of the solder resist is caused. The thickness of the solder resist dry film can be 30-50 μm. The thickness of the solder resist dry film can also be 25-40 μm.

Preferably, the main component of the photo-coating film is acrylic resin, and the photo-coating film is coated on the surface of the polyester film in a spraying manner so as to ensure the integrity of coating and the accuracy of coating thickness; the protective film is made of polyethylene.

Preferably, in the curing step, an oven is adopted, the temperature is controlled to be 150-160 ℃, and the curing time is 60-70 min. If the temperature and time of the curing treatment exceed the lower limits, the curing cannot be completed and the dry film tends to fall off. If the temperature and time exceed the upper limits, the dry film discolors and becomes brittle.

Preferably, the copper-clad plate is in a vertical state when cleaned by the cleaning device, so that sundries on the surface of the copper-clad plate can be smoothly discharged by plate grinding and sand blasting, the copper-clad plate is cleaned more thoroughly, cleaning water flows down more quickly, cleaning time is saved, and park consumption is reduced. In the traditional circuit board production process, the copper-clad plate is mostly cleaned in a flat mode, and because the copper-clad plate is of a planar structure, water is accumulated easily when the copper-clad plate is laid down, water for cleaning is not easy to discharge, and water blowing needs a longer time. Meanwhile, the method is not beneficial to the discharge of impurities, so that the surface of the copper-clad plate is easy to have impurity residues, and the cleaning effect is poor.

Example 2

A cleaning device for copper-clad plate washing and stoving processing includes: cleaning apparatus 10, output track 70, and frame 80.

The cleaning device 10 is of a box-type structure, and is provided with a cleaning station 20, a blow-drying station 30 and a drying station 40 from an inlet end to an outlet end in sequence; the cleaning equipment 10 is provided with a conveying track 50, and a limiting groove 60 is arranged above the conveying track 50; the conveying track 50 and the limiting groove 60 are arranged along the inlet and outlet direction of the cleaning equipment 10; during cleaning, the copper-clad plate is vertically placed between the conveying track 50 and the limiting groove 60.

The output rail 70 is used for driving the material frame 80 to move, and the moving direction of the material frame 80 is perpendicular to the inlet and outlet direction of the cleaning device 10.

More specifically, as shown in fig. 8 and 9, a plurality of rows of first rollers 81 are disposed on both the bottom plate and the top plate of the material frame 80, and each row of the first rollers 81 on the bottom plate and the top plate of the material frame 80 is disposed in pairs. The axis of the first roller 81 is parallel to the bottom plate and the top plate of the material frame 80. A row of second rollers 82 is arranged between each row of first rollers 81 on the bottom plate and the top plate of the material frame 80, and the axis of each second roller 82 is perpendicular to the bottom plate and the top plate of the material frame 80.

After the copper-clad plate is cleaned, the copper-clad plate is discharged from the outlet end of the cleaning device 10 and fed into the material feeding frame 80. Supporting one side of the copper-clad plate by using the first roller 81 of the bottom plate or the top plate of the material frame 80; at the moment, the copper-clad plates are in the same state as the copper-clad plates in the cleaning process and are in a vertical state, and the copper-clad plates sequentially enter the material frame 80 from the outlet section of the cleaning equipment 10. When one copper-clad plate is fed, the output rail 70 drives the material frame 80 to move for a preset distance, and the preset distance is the same as the distance between the adjacent second rollers 82. The copper-clad plates are positioned between the two rows of second rollers 82 after entering the material frame 80, and the second rollers 82 are utilized to separate the adjacent copper-clad plates, so that the copper-clad plates are prevented from rubbing with each other to generate scratches. The height of the second roller 82 is smaller than the width of a safety area reserved on the edge of the copper-clad plate.

In the subsequent production, the copper-clad plate needs to be horizontally placed and conveyed, so that the material frame 80 needs to be rotated by 90 degrees. As shown in fig. 10, after the material frame 80 rotates 90 °, the copper-clad plate is in a horizontal state, and at this time, the axis of the second roller 82 is also in a horizontal state, and the second roller 82 is used for supporting the copper-clad plate. When the copper-clad plate is output from the material frame 80, the second idler wheel 82 also rotates along with the copper-clad plate, so that the copper-clad plate can move conveniently.

More specifically, as shown in fig. 4, the conveying track 50 is provided with a plurality of conveying rollers 51 along the moving direction array of the copper-clad plate, each conveying roller 51 includes a rotating shaft 511, a pair of disks 512 are arranged at intervals on the rotating shaft 511, the disks 512 are coaxial with the rotating shaft 511, a rubber sleeve 513 is sleeved on the periphery of each disk 512, a V-shaped groove 5131 is arranged in the middle section of each rubber sleeve 513, and an interval is arranged between the bottom surface of each V-shaped groove 5131 and the outer wall of the rotating shaft 511. As shown in fig. 5, during cleaning, one side of the copper-clad plate is placed in the V-shaped groove 5131, and under the action of gravity of the copper-clad plate, the rubber sleeve 513 elastically deforms, so that the bottom surface of the V-shaped groove 5131 contacts with the outer wall of the rotating shaft 511. And the side wall of the V-shaped groove 5131 contacts with both sides of the copper-clad plate to increase the friction force of rotation, so that the copper-clad plate can move stably. Meanwhile, the rubber sleeve 513 is made of rubber, so that the surface of the copper-clad plate can be prevented from being scratched. On the other hand, a safety area is reserved on the periphery of the copper clad plate, and a circuit diagram is not arranged in the safety area, so that the use is not influenced even if a small amount of scratches exist on the side edge of the copper clad plate. The traditional cleaning mode utilizes the surface of the copper clad laminate to contact with the conveying roller, and although the traditional conveying roller is made of plastic, the traditional cleaning mode still can generate slight scratches on the wiring surface of the copper clad laminate.

More specifically, as shown in fig. 3 and 6, the limiting groove 60 includes a groove steel 61, two columns of cylindrical rollers 62 are disposed at the bottom of the groove steel 61, a gap is formed between the two columns of cylindrical rollers 62, when the copper-clad plate is cleaned, the copper-clad plate passes through the two columns of cylindrical rollers 62, and the inclination of the copper-clad plate is prevented by the cylindrical rollers 62.

Preferably, the cleaning station 20 includes a pair of water spraying pipes 21, and the water spraying pipes 21 are disposed on two sides of the channel steel 61 and are respectively used for cleaning two side surfaces of the copper-clad plate.

Preferably, as shown in fig. 3 and 6, the blow-drying station 30 comprises a pair of transverse blowing pipes 31 and a plurality of longitudinal blowing pipes 32 to accelerate the blowing operation of the cleaning liquid; the transverse air blowing pipes 31 are arranged on two sides of the channel steel 61 and are respectively used for blowing off liquid on two sides of the copper-clad plate from top to bottom; the longitudinal gas blowing pipes 32 are vertically arranged and are respectively used for blowing off the liquid on the surface of the copper clad plate from the outlet end to the inlet end of the cleaning equipment 10.

More preferably, as shown in fig. 6 and 7, the transverse blowing pipe 31 and the water spraying pipe 21 are both of a circular pipe structure. Clamping rings 63 are arranged on two sides of the groove steel 61, locking screws 64 penetrate through the clamping rings 63, and openings 631 are formed in the bottoms of the clamping rings 63; the transverse gas blowing pipe 31 and the water spraying pipe 21 are both rotatably arranged in the clamping ring 63; the locking screw 64 is used for pressing and fixing the transverse blowing pipe 31 and the spray pipe 21; the nozzles of the transverse blowing pipe 31 and the spray pipe 21 respectively pass through the corresponding openings 631. The purpose of this kind of structural design is to adjust the angle between the horizontal blowpipe 31 and the nozzle of the spray pipe 21 and the surface of the copper clad plate to ensure the best cleaning and drying effect.

The washing and drying treatment of the copper-clad plate by using the washing device comprises the following steps:

(1) the copper-clad plate is placed from the inlet end of the cleaning device 10, placed on the conveying roller 51, placed in the V-shaped groove 5131 at the bottom edge and placed between the two columns of cylindrical rollers 62 at the top edge. The conveying rollers 51 drive the copper-clad plate to move towards the outlet of the cleaning equipment 10, and the conveying rollers 51 are driven by a transmission belt or a transmission chain in a unified mode.

(2) Firstly, the copper-clad plate passes through a cleaning station 20, and the water spraying pipe 21 washes two surfaces of the copper-clad plate from the upper part to the lower part, so that impurities on the surface of the copper-clad plate smoothly flow down along with water flow, and the residual adhesion is reduced.

(3) Then the copper clad laminate passes through a blow-drying station 30, and a transverse air blowing pipe 31 blows high-pressure air flow to the surface of the copper clad laminate from top to bottom, so that liquid remained on the surface of the copper clad laminate flows down rapidly. Meanwhile, the copper clad laminate can be blown at high pressure through the longitudinal blowing pipe 31 in the moving process to further blow off the liquid on the surface of the copper clad laminate.

(4) And finally, the copper-clad plate is dried through a drying station, so that the water vapor on the surface of the copper-clad plate can be dried, the drying of the plate surface is ensured, and the bonding force of the copper-clad plate and the solder-resisting dry film is improved. And after drying, outputting the copper-clad plate from the outlet end of the cleaning equipment 10, and entering the material frame 80 for temporary suspension and transfer. The material frame 80 adopts a closed structure to ensure that the copper-clad plate is not secondarily polluted.

The foregoing is only a preferred embodiment of the present invention and is not intended to be exhaustive or to limit the invention. It will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the scope of the invention.