CN109511230B - Solder mask jet printing processing method for circuit board - Google Patents

Abstract

The invention discloses a solder resist spray printing processing method for circuit boards. The ink is directly printed on the preset position of the circuit board; the third step, UV pre-curing: the ink printed on the circuit board is initially cured; the fourth step, laser repair: use a laser cutting machine to remove the unnecessary The position of the ink-covered graphic area infiltrated into the ink is repaired and smoothed; the fifth step, thermal curing: the ink sprayed on the circuit board is completely cured, and the surface forms a stable cross-linked structure; the above processing method eliminates the need for alignment exposure. and development process, shorten the process time and improve the production efficiency; cancel the production of screen plate, the production of exposure film, the consumption of developer liquid and the treatment of waste water, which saves labor costs; reduces equipment investment, and is suitable for all different plate thickness and Circuit boards of different sizes save the time of changing boards.

Description

A kind of circuit board solder resist spray printing processing method

technical field

The invention relates to the technical field of manufacturing printed circuit boards, in particular to a method for solder resist spray printing processing of circuit boards.

Background technique

The purpose of the solder mask process of the circuit board is to tin only the exposed copper part during the SMT soldering process, and to apply ink to the parts of the circuit pattern that do not need to be soldered, so as to prevent tinning. At the same time, after the circuit board is made, the layer of ink can permanently protect the circuit from being corroded in the atmosphere, and has a moisture-proof function to ensure the reliability of electrical insulation between circuits.

Two types of inks commonly used in the solder mask process are photosensitive ink and UV+ heat-curable ink;

The production methods of printing ink on circuit boards mainly include screen printing, curtain coating, reel coating, electrostatic spraying, and air spraying; the widely used method is screen printing.

The main process flow of solder mask production:

Pre-treatment → screen printing first side → pre-baking → screen printing second side → pre-baking → alignment exposure → development → heat curing

Major equipment:

Grinding machine, screen printing machine, coating machine, exposure machine, drying tunnel, developing machine and light curing machine, oven, etc.

No matter which method is used to print ink, it needs to go through the steps of oven baking, exposure machine exposure, developing machine development, etc. The manufacturing cycle is long, and it needs to consume a lot of labor, water, electricity, auxiliary materials, and raw materials. Exposure film is used for alignment exposure, and developer syrup is consumed for development. At the same time, the operation, maintenance and maintenance of related equipment all require very high skills of the personnel who operate the equipment.

Therefore, the circuit board solder mask production process has long been a difficult process in circuit board production. The process is complicated, the production cycle is long (normal production time takes 6-8 hours), and it is dependent on skilled screen printers.

SUMMARY OF THE INVENTION

Based on this, the present invention provides a solder resist spray printing processing method for a circuit board.

A circuit board solder resist spray printing processing method, comprising:

The first step, pretreatment, removes oxides, oil traces and impurities on the circuit board, and roughens the copper surface;

The second step, spray printing: directly spray the ink on the preset position of the circuit board;

The third step, UV pre-curing: initial curing of the ink printed on the circuit board;

The fourth step, laser repair: use a laser cutting machine to repair and level the position where the ink penetrates into the graphic area that does not need to be covered by ink on the circuit board;

The fifth step, thermal curing: the ink sprayed on the circuit board is completely cured, and a stable cross-linked structure is formed on the surface.

In one embodiment, the jet printing includes the following steps:

2.1, print the first side of the circuit board;

2.2, flip the circuit board;

2.3, print the second side of the circuit board.

In one embodiment, the thickness of the inkjet printing ink is 5um-100um.

In one embodiment, the color of the ink jetted includes at least one of green, blue, black, red and white.

The beneficial effects of the above-mentioned circuit board solder resist spray printing processing method relative to the existing solder resist manufacturing process are as follows:

1. The alignment exposure and development processes are omitted, the process time is shortened, and the production efficiency is improved.

2. The production of screen plate, the production of exposure film, the consumption of developing potion and the treatment of waste water are cancelled, which saves labor and material costs.

3. Exposure machines, developing machines, and screen production equipment can all be canceled, which reduces equipment investment, reduces equipment occupation and water and electricity consumption.

4. Applicable to all circuit boards of different thicknesses and sizes, saving the time of changing boards.

5. The method is simple to operate, and can also be operated by ordinary screen printers, which reduces the dependence of skilled screen printers.

Description of drawings

FIG. 1 is a block diagram of a flow chart of a circuit board solder resist spray printing processing method according to the present invention.

Detailed ways

In order to make the above objects, features and advantages of the present invention more clearly understood, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or an intervening element may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for the purpose of illustration only and do not represent the only embodiment.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terms used herein in the description of the present invention are for the purpose of describing specific embodiments only, and are not intended to limit the present invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

As shown in FIG. 1 , a method for printing a solder mask of a circuit board includes:

The first step, pretreatment, removes oxides, oil traces and impurities on the circuit board, and roughens the copper surface;

The second step, spray printing: directly spray the ink on the preset position of the circuit board;

The third step, UV pre-curing: initial curing of the ink printed on the circuit board;

The fourth step, laser repair: use a laser cutting machine to repair and level the position where the ink penetrates into the graphic area that does not need to be covered by ink on the circuit board;

The fifth step, thermal curing: the ink sprayed on the circuit board is completely cured, and a stable cross-linked structure is formed on the surface.

When starting the solder mask treatment on the circuit board,

The first step, pretreatment, removes oxides, oil traces and impurities on the circuit board surface, roughens the copper surface; enhances the bonding force between the ink and the circuit board surface;

The second step, spray printing: the ink is directly sprayed on the preset position of the circuit board; the spray printing process is to spray the special spray ink directly on the circuit according to the preset position of the welding data through the high-precision nozzle of the inkjet printer On the board, apply ink to the parts that do not need to be soldered, and keep the window open without ink to cover the parts of the pattern that need to be exposed.

The third step, UV pre-curing: initial curing of the ink printed on the circuit board;

The fourth step, laser repair: use a laser cutting machine to repair and smooth the position where the graphic area on the circuit board that does not need to be covered by ink penetrates into the ink; because the ink will have a certain leveling, there will be slight ink leakage at the edge of the window. Therefore, use a laser cutting machine to repair and level the high-definition graphic area that does not require ink coverage. By adjusting the laser pulse and frequency, the oozing ink can be removed without damaging the circuit on the circuit board.

The fifth step, thermal curing: the ink sprayed on the circuit board is completely cured, and a stable cross-linked structure is formed on the surface.

In this way, the beneficial effects of a circuit board solder resist spray printing processing method relative to the existing solder resist manufacturing process are as follows:

1. The alignment exposure and development processes are omitted, the process time is shortened, and the production efficiency is improved.

2. The production of screen plate, the production of exposure film, the consumption of developing potion and the treatment of waste water are cancelled, which saves labor and material costs.

3. Exposure machines, developing machines, and screen production equipment can all be canceled, which reduces equipment investment, reduces equipment occupation and water and electricity consumption.

4. Applicable to all circuit boards of different thicknesses and sizes, saving the time of changing boards.

5. The method is simple to operate, and can also be operated by ordinary screen printers, which reduces the dependence of skilled screen printers.

Further, in order to enable the circuit to achieve a better printing effect, the printing includes the following steps:

2.1, print the first side of the circuit board;

2.2, flip the circuit board;

2.3, print the second side of the circuit board.

One of the examples is:

The first step, pretreatment, removes oxides, oil traces and impurities on the circuit board, and roughens the copper surface;

The second step is to print the first side of the circuit board: directly print the ink on the preset position on the first side of the circuit board;

The third step is to flip the circuit board;

The fourth step is to print the second side of the circuit board; directly spray the ink on the preset position of the second side of the circuit board;

The fifth step, UV pre-curing: preliminarily solidify the ink printed on the first and second sides of the circuit board;

The sixth step, laser repair: use a laser cutting machine to repair and flatten the graphic areas on the first and second sides of the circuit board that do not need ink coverage;

The seventh step, thermal curing: the ink sprayed on the first side and the second side of the circuit board is completely cured, and the surface forms a stable cross-linked structure.

Another example of this is:

The first step, pretreatment, removes oxides, oil traces and impurities on the circuit board, and roughens the copper surface;

The second step is to print the first side of the circuit board: directly print the ink on the preset position on the first side of the circuit board;

The third step, the first UV pre-curing: initial curing of the ink sprayed on the first surface of the circuit board;

The third step is to flip the circuit board;

The fourth step is to print the second side of the circuit board; directly spray the ink on the preset position of the second side of the circuit board;

The fifth step, the second UV pre-curing: preliminarily solidify the ink sprayed on the second surface of the circuit board;

The sixth step, laser repair: use a laser cutting machine to repair and flatten the graphic areas on the first and second sides of the circuit board that do not need ink coverage;

The seventh step, thermal curing: the ink sprayed on the first side and the second side of the circuit board is completely cured, and the surface forms a stable cross-linked structure.

In this way, during the solder mask process of the circuit board, both sides of the circuit board can be spray-printed first and then UV pre-cured, or both sides of the circuit board can be spray-printed and UV pre-cured in turn, making the whole process more applicable. The entire circuit board will not be damaged due to the wrong sequence of printing and UV pre-curing.

Further, the thickness of the printing ink is 5um-100um.

Further, the ink color of the jet printing includes at least one of green, blue, black, red and white.

The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity, all possible combinations of the technical features in the above-described embodiments are not described. However, as long as there is no contradiction between the combinations of these technical features, All should be regarded as the scope described in this specification.

The above-mentioned embodiments only represent several embodiments of the present invention, and the descriptions thereof are more specific and detailed, but should not be construed as a limitation on the scope of the invention patent. It should be pointed out that for those skilled in the art, without departing from the concept of the present invention, several modifications and improvements can be made, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention should be subject to the appended claims.

Claims (4)

1. A circuit board solder resist spray printing processing method is characterized in that: comprising: The first step, pretreatment, removes oxides, oil traces and impurities on the circuit board, and roughens the copper surface; The second step, spray printing: directly spray the ink on the preset position of the circuit board; The third step, UV pre-curing: initial curing of the ink printed on the circuit board; The fourth step, laser repair: use a laser cutting machine to repair and level the position where the ink penetrates into the graphic area that does not need to be covered by ink on the circuit board; The fifth step, thermal curing: the ink sprayed on the circuit board is completely cured, and a stable cross-linked structure is formed on the surface. 2. The method for processing circuit board solder resist spray printing according to claim 1, wherein the spray printing comprises the following steps: 2.1, print the first side of the circuit board; 2.2, flip the circuit board; 2.3, print the second side of the circuit board. 3. The method for processing circuit board solder resist jet printing according to claim 1, wherein the jet printing ink thickness is 5um-100um. 4 . The method of claim 1 , wherein the color of the ink to be printed includes at least one of green, blue, black, red and white. 5 .

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