阅读说明：本技术 线路板阻焊层的制作方法及线路板 (Manufacturing method of circuit board solder mask and circuit board ) 是由 周睿 吴杰 刘海龙 于 2019-11-06 设计创作，主要内容包括：本发明公开一种线路板阻焊层的制作方法及线路板。其中,所述线路板阻焊层的制作方法包括以下步骤：提供具有通孔的半成品线路板；采用带挡点网版对所述半成品线路板的表面进行第一次丝印操作,以使得油墨覆盖通孔周围且不进入通孔内；采用不带挡点网版对第一次丝印操作后的表面进行第二次丝印操作,以使得油墨覆盖所述通孔的周围并部分进入所述通孔内；曝光显影,并冲洗掉进入通孔内的油墨,之后进行固化处理。本发明的技术方案能够同时满足油墨完全覆盖通孔周围且不进入孔内的要求。(The invention discloses a manufacturing method of a solder mask layer of a circuit board and the circuit board. The manufacturing method of the circuit board solder mask comprises the following steps: providing a semi-finished circuit board with a through hole; carrying out first silk-screen printing operation on the surface of the semi-finished circuit board by adopting a screen printing plate with blocking points so that printing ink covers the periphery of the through hole and does not enter the through hole; carrying out second screen printing operation on the surface after the first screen printing operation by adopting a screen printing plate without a stop point, so that printing ink covers the periphery of the through hole and partially enters the through hole; and exposing and developing, washing off the ink entering the through holes, and then carrying out curing treatment. The technical scheme of the invention can simultaneously meet the requirement that the printing ink completely covers the periphery of the through hole and does not enter the through hole.)

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

providing a semi-finished circuit board with a through hole;

carrying out first silk-screen printing operation on the surface of the semi-finished circuit board by adopting a screen printing plate with blocking points so that printing ink covers the periphery of the through hole and does not enter the through hole;

carrying out second screen printing operation on the surface after the first screen printing operation by adopting a screen printing plate without a stop point, so that printing ink covers the periphery of the through hole and partially enters the through hole;

and exposing and developing, washing off the ink entering the through holes, and then carrying out curing treatment.

2. A method for making a solder mask of a circuit board according to claim 1, wherein the number T of the screen mesh of the screen plate with blocking points is 39T to 41T;

and/or the mesh yarn T number of the screen plate without the blocking point is 120T to 140T.

3. The method for manufacturing the solder mask of the circuit board according to claim 1, wherein the screen plate with the oil stopping points is provided with oil stopping points, the relative positions of the oil stopping points are consistent with the relative positions of the through holes, and the outer diameters of the oil stopping points are larger than the diameters of the through holes.

4. A method for making a solder mask for a circuit board according to claim 3, wherein the outer diameter of the oil stopping point is defined as D1, the diameter of the through hole is D2, and D1 is D2+0.2 mm.

5. A method for making a solder mask for a circuit board according to claim 1, wherein the thickness of the ink covering the periphery of the through hole in the second screen printing operation is in the range of 13 μm to 17 μm.

6. The method for manufacturing the solder mask of the circuit board according to claim 1, wherein in the step of performing the first screen printing operation on the surface of the semi-finished circuit board by using the screen printing plate with the blocking points, the method comprises the following steps:

using a screen printer, the pressure range of a scraper is 6kg/cm²To 8kg/cm²And then, printing ink with the viscosity ranging from 200dPa & s to 250dPa & s to the surface of the semi-finished product circuit board through a screen printing plate with blocking points, wherein the screen printing speed is 2m/min to 3 m/min.

7. The method for manufacturing the solder mask of the circuit board according to claim 1, wherein in the step of performing the second screen printing operation on the surface after the first screen printing operation by using the screen printing plate without the stop points, the method comprises the following steps:

using a screen printer, the pressure range of a scraper is 6kg/cm²To 8kg/cm²Then, printing ink with the viscosity ranging from 200dPa & s to 250dPa & s on the surface after the first screen printing operation by a screen printing plate without a stop point, wherein the screen printing speed is 2m/min to 3 m/min.

8. A method for making a solder mask for a circuit board according to claim 1, wherein in the step of exposing and developing, washing off the ink entering the through hole, and then performing a curing process, the method comprises:

the exposure machine is aligned with the printing ink around the through hole to emit ultraviolet light, so that the printing ink around the through hole is subjected to photopolymerization reaction;

washing off the ink entering the through hole by adopting a sodium carbonate solution;

and curing the ink around the through hole for 60min to 70min at the temperature ranging from 140 ℃ to 160 ℃.

9. A method for making a solder mask for a circuit board according to any one of claims 1 to 8, wherein before the step of performing the first screen printing operation on the surface of the semi-finished circuit board by using the screen plate with the blocking points, the method further comprises:

and carrying out acid washing, plate grinding, water washing and drying on the surface of the semi-finished product circuit board.

10. A wiring board characterized in that the wiring board is provided with a through hole, a surface of the wiring board not provided with the through hole is provided with a solder resist layer, and the solder resist layer is manufactured by the method for manufacturing the solder resist layer of the wiring board according to any one of claims 1 to 9.

Technical Field

The invention relates to the technical field of circuit board manufacturing, in particular to a manufacturing method of a circuit board solder mask and a circuit board.

Background

Disclosure of Invention

The invention mainly aims to provide a method for manufacturing a solder mask layer of a circuit board and the circuit board, and aims to meet the requirement that ink completely covers the periphery of a through hole and does not enter the through hole.

In order to achieve the purpose, the manufacturing method of the circuit board solder mask provided by the invention comprises the following steps:

providing a semi-finished circuit board with a through hole;

carrying out first silk-screen printing operation on the surface of the semi-finished circuit board by adopting a screen printing plate with blocking points so that printing ink covers the periphery of the through hole and does not enter the through hole;

carrying out second screen printing operation on the surface after the first screen printing operation by adopting a screen printing plate without a stop point, so that printing ink covers the periphery of the through hole and partially enters the through hole;

and exposing and developing, washing off the ink entering the through holes, and then carrying out curing treatment.

Optionally, the number of the screen yarns T of the screen printing plate with the blocking points is 39T to 41T; and/or the mesh yarn T number of the screen plate without the blocking point is 120T to 140T.

Optionally, the screen plate with the oil blocking points is provided with oil blocking points, the relative positions of the oil blocking points are consistent with the relative positions of the through holes, and the outer diameters of the oil blocking points are larger than the diameters of the through holes.

Optionally, the outer diameter of the oil stopping point is defined as D1, and the diameter of the through hole is D2, D1 is D2+0.2 mm.

Optionally, the thickness of the ink covering the periphery of the through holes in the second screen printing operation ranges from 13 μm to 17 μm.

Optionally, in the step of performing a first screen printing operation on the surface of the semi-finished circuit board by using a screen printing plate with blocking points, the method includes:

using a screen printer, the pressure range of a scraper is 6kg/cm²To 8kg/cm²And then, printing ink with the viscosity ranging from 200dPa & s to 250dPa & s to the surface of the semi-finished product circuit board through a screen printing plate with blocking points, wherein the screen printing speed is 2m/min to 3 m/min.

Optionally, in the step of performing the second screen printing operation on the surface after the first screen printing operation by using the screen printing plate without the stop point, the method includes:

using a screen printer, the pressure range of a scraper is 6kg/cm²To 8kg/cm²Then, printing ink with the viscosity ranging from 200dPa & s to 250dPa & s on the surface after the first screen printing operation by a screen printing plate without a stop point, wherein the screen printing speed is 2m/min to 3 m/min.

Optionally, in the step of exposing, developing, and washing away the ink entering the through hole, and then performing a curing process, the method includes:

the exposure machine is aligned with the printing ink around the through hole to emit ultraviolet light, so that the printing ink around the through hole is subjected to photopolymerization reaction;

washing off the ink entering the through hole by adopting a sodium carbonate solution;

and curing the ink around the through hole for 60min to 70min at the temperature ranging from 140 ℃ to 160 ℃.

Optionally, before the step of performing a first screen printing operation on the surface of the semi-finished circuit board by using a screen printing plate with blocking points, the method further includes:

and carrying out acid washing, plate grinding, water washing and drying on the surface of the semi-finished product circuit board.

The invention also provides a circuit board, wherein the circuit board is provided with a through hole, the surface of the circuit board, which is not provided with the through hole, is provided with a solder mask, and the solder mask is manufactured by the manufacturing method of the solder mask of the circuit board.

Firstly, performing first silk-screen printing operation on the surface of a semi-finished circuit board with a through hole by adopting a screen plate with blocking points so as to enable ink to cover the periphery of the through hole and not enter the through hole; then, carrying out second silk-screen printing operation on the surface after the first silk-screen printing operation by adopting a screen plate without a stop point so as to enable the printing ink to cover the periphery of the through hole and partially enter the through hole, thus the second silk-screen printing operation can carry out printing ink covering on the position which is not covered with the printing ink at the periphery of the through hole 10 in the first silk-screen printing operation; and then carrying out exposure and development operation, washing off a small amount of printing ink entering the through hole, and carrying out curing treatment to obtain the solder mask of the circuit board. The solder mask layer manufactured by the invention can completely cover the periphery of the through hole and does not enter the through hole, and can meet the special insulation requirement and heat dissipation requirement of partial products.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the structures shown in the drawings without creative efforts.

FIG. 1 is a schematic flow chart showing steps of a method for manufacturing a solder mask layer of a circuit board according to an embodiment of the present invention;

FIG. 2 is a schematic flow chart showing steps of another embodiment of the method for manufacturing a solder mask layer of a circuit board according to the present invention;

FIG. 3 is a flowchart illustrating a detailed step of step S40;

fig. 4 is a schematic diagram of the first silk-screen operation in step S20.

The reference numbers illustrate:

reference numerals	Name (R)	Reference numerals	Name (R)
				100	Semi-finished circuit board	200	Screen plate with blocking points
10	Through hole	21	Oil stopping point

The implementation, functional features and advantages of the objects of the present invention will be further explained with reference to the accompanying drawings.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In addition, the technical solutions in the embodiments of the present invention may be combined with each other, but it must be based on the realization of those skilled in the art, and when the technical solutions are contradictory or cannot be realized, such a combination of technical solutions should not be considered to exist, and is not within the protection scope of the present invention.

The invention provides a manufacturing method of a circuit board solder mask. In the manufacturing process of the circuit board, due to special insulation requirements and heat dissipation requirements, part of products need to cover ink around the through hole 10 of the circuit board, and the ink can not enter the through hole 10.

Referring to fig. 1 and 4, in an embodiment of the method for manufacturing a solder mask layer of a circuit board of the present invention, the method for manufacturing a solder mask layer of a circuit board includes the following steps:

s10, providing a semi-finished circuit board 100 with a through hole 10;

s20, performing a first silk-screen printing operation on the surface of the semi-finished circuit board 100 by using the screen printing plate 200 with the blocking points, so that the printing ink covers the periphery of the through hole 10 and does not enter the through hole 10;

s30, performing a second screen printing operation on the surface after the first screen printing operation by using the screen printing plate 200 without the stop points, so that the printing ink covers the periphery of the through hole 10 and partially enters the through hole 10;

s40, exposure and development are performed, and the ink entering the through hole 10 is washed away, followed by curing treatment.

Specifically, the surface of the semi-finished circuit board 100 is provided with a plurality of through holes 10, and generally, the number of the through holes 10 is multiple, so as to realize a heat dissipation function or other functions. Firstly, a first silk-screen operation is carried out on the surface of a semi-finished product circuit board 100 to enable ink to cover the periphery of a through hole 10, a screen plate 200 with blocking points is adopted in the silk-screen operation, and oil blocking points 20 are arranged on the screen plate 200 with the blocking points, so that the oil blocking points 20 are arranged in a mode of aligning to the through hole 10 during the operation, the ink cannot enter the through hole 10, and the positions, corresponding to the oil blocking points 20, of the periphery of the through hole 10 cannot be covered with the ink due to the fact that the screen plate is provided with the oil blocking points 20. And then, carrying out second screen printing operation by adopting a screen printing plate without blocking points, and covering the positions, which are not covered with the printing ink, around the through holes 10 in the first screen printing operation by using the printing ink, wherein a small amount of printing ink enters the through holes 10 because the screen printing plate without the blocking points is adopted at this time. And then carrying out exposure and development operation, washing the printing ink entering the through hole 10, and then carrying out curing treatment to obtain the solder mask. The solder mask layer manufactured by the invention can completely cover the periphery of the through hole 10 and does not enter the through hole 10, and can meet the special insulation requirement and heat dissipation requirement of partial products.

Therefore, it can be understood that, in the technical scheme of the present invention, firstly, the screen printing plate 200 with the blocking points is adopted to perform a first screen printing operation on the surface of the semi-finished circuit board 100 with the through hole 10, so that the ink covers the periphery of the through hole 10 and does not enter the through hole 10; then, carrying out second silk-screen printing operation on the surface after the first silk-screen printing operation by adopting the screen plate 200 without the stop points so as to enable the printing ink to cover the periphery of the through hole 10 and partially enter the through hole 10, thus the second silk-screen printing operation can carry out printing ink covering on the position, which is not covered with the printing ink, of the periphery of the through hole 10 in the first silk-screen printing operation; and then carrying out exposure and development operation, washing off a small amount of printing ink entering the through hole 10, and then carrying out curing treatment to obtain the solder mask of the circuit board. The solder mask layer manufactured by the invention can completely cover the periphery of the through hole 10 and does not enter the through hole 10, and the special insulation requirement and the heat dissipation requirement of partial products can be met.

Optionally, the number of the screen T of the screen with blocking points 200 is 39T to 41T. In general, the mesh number of the screen with blocking dots 200 adopted in the first screen printing operation is larger than that of a conventional screen printing plate, so that the lower oil layer of the screen printing operation is thinner, and the depth of the position corresponding to the oil blocking dots 20 around the through holes 10 is smaller, so as to facilitate the subsequent ink covering operation at the position, so that the screen with blocking dots 200 with proper mesh number is selected, for example, the mesh number T of the screen with blocking dots 200 is 39T, 40T or 41T, and it should be noted that the mesh number T and the mesh number of the screen are in a linear and positive proportional relationship.

Alternatively, the number of the screen yarns T of the screen plate 200 without the bar point is 120T to 140T.

Since the second screen printing operation is mainly to coat the positions, which are not covered by the ink, around the through holes 10 in the first screen printing operation with the ink, the thickness of the lower oil layer in the second screen printing operation is selected to more effectively coat the through holes and to more easily remove the ink in the through holes 10, and the thickness of the lower oil layer in the screen printing operation is related to the mesh number of the screen printing plate, so that the screen printing plate 200 without the blocking points with the appropriate mesh number is selected, for example, the number of the screen yarns T of the screen printing plate 200 without the blocking points is 120T, 125T, 130T, 135T or 140T. Here, the screen plate 200 without the stop points adopts a screen plate with a relatively large mesh number, so that an oil layer is thinner during the screen printing operation, and the subsequent removal operation of the ink in the through holes 10 is facilitated.

It can be understood that the screen plate with oil blocking points 200 is provided with oil blocking points 20, the relative positions of the oil blocking points 20 are consistent with the relative positions of the through holes 10, and the outer diameter of the oil blocking points 20 is larger than the diameter of the through holes 10.

Because the surface of the circuit board is provided with a plurality of through holes 10, the screen printing plate with blocking points 200 is provided with a plurality of oil blocking points 20, wherein the relative positions of the oil blocking points 20 are consistent with the relative positions of the through holes 10, and the outer diameters of the oil blocking points 20 are larger than the diameters of the through holes 10, so that when the first silk-screen printing operation is carried out, the oil blocking points 20 on the surface of the screen printing plate with blocking points 200 are aligned with the through holes 10, and ink covers the periphery of the through holes 10 and cannot enter the through holes 10.

Referring to fig. 4, the outer diameter of the oil stopping point 20 is defined as D1, the diameter of the through hole 10 is defined as D2, and D1 is D2+0.2 mm. When selecting the screen plate with blocking dots 200, the screen plate with the oil blocking dots 20 of an appropriate size is selected according to the diameter of the through-hole 10, and the outer diameter of the oil blocking dots 20 is generally 0.2mm larger than the diameter of the through-hole 10.

Further, the thickness of the ink covering the periphery of the through-hole 10 in the second screen printing operation ranges from 13 μm to 17 μm. During the second screen printing operation, the oil feeding amount, that is, the thickness of the ink covering the periphery of the through hole 10, is strictly controlled, so that a small amount of ink entering the through hole 10 can be removed more easily. Typically, the thickness of the ink covering the periphery of the through-hole 10 in the second screen printing operation is controlled to be 13 μm, 14 μm, 15 μm, 16 μm, or 17 μm.

Further, in step S20, the step of performing a first silk-screen printing operation on the surface of the semi-finished circuit board 100 by using the screen plate 200 with the blocking points includes:

using a screen printer, the pressure range of a scraper is 6kg/cm²To 8kg/cm²And then, printing ink with the viscosity ranging from 200dPa & s to 250dPa & s is subjected to silk-screen printing to the surface of the semi-finished product circuit board 100 through the screen printing plate with the blocking points 200, wherein the silk-screen printing speed is 2m/min to 3 m/min.

Here, during the first screen printing operation, the pressure of the squeegee was controlled to 6kg/cm²、7kg/cm²Or 8kg/cm²The ink used has a viscosity of 200 dPas, 210 dPas, 220 dPas, 230 dPas, 240 dPas or 250 dPas, and the speed of the screen printing operation is 2m/min, 2.5m/min or 3m/min, so that the ink can uniformly cover the periphery of the through-hole 10.

Further, in step S30, the step of performing the second screen printing operation on the surface after the first screen printing operation by using the screen printing plate 200 without the dot includes:

using a screen printer, the pressure range of a scraper is 6kg/cm²To 8kg/cm²Then, the printing ink with the viscosity ranging from 200 dPa.s to 250 dPa.s is subjected to silk-screen printing on the surface after the first silk-screen printing operation through a screen plate 200 without stop points, and the silk-screen printing speed is 2m/min to 3 m/min.

In the process of carrying out the second silk-screen printing operation, the pressure of the scraper is controlled to be 6kg/cm²、7kg/cm²Or 8kg/cm²The ink used has a viscosity of 200 dPas, 210 dPas, 220 dPas, 230 dPas, 240 dPas or 250 dPas, and the speed of the screen printing operation is 2m/min, 2.5m/min or 3m/min, so that the ink can uniformly cover the uncovered positions around the through-holes 10 in the first screen printing operation.

Further, referring to fig. 3, in step S40, the steps of exposing, developing, washing off the ink entering into the through hole 10, and then performing a curing process include:

step S401, aligning an exposure machine to the ink around the through hole 10 to emit ultraviolet light, so that the ink around the through hole 10 is subjected to photopolymerization reaction;

step S402, washing off the ink entering the through hole 10 by adopting a sodium carbonate solution;

and S403, curing the printing ink around the through hole 10 for 60min to 70min at the temperature of 140 ℃ to 160 ℃.

Specifically, the exposure machine is opened and aligned with the ink around the through hole 10, the ultraviolet light emitted by the exposure machine irradiates the surface of the ink around the through hole 10, the ink performs photopolymerization under the irradiation of the ultraviolet light, the amount of the ink entering the through hole 10 does not pass through the irradiation of the ultraviolet light, and the ink adhered to the inner wall of the through hole 10 can be washed away by the sodium carbonate solution; the ink around the through hole 10 will not react with the sodium carbonate due to photopolymerization, and will remain on the surface of the circuit board. And then, curing the printing ink around the through hole 10 at the temperature of 140 ℃, 150 ℃ or 160 ℃, so that a solder mask layer can be obtained by solidification and has a protection effect. The curing time is 60min, 65min or 70 min.

Referring to fig. 2, in step S20, before the step of performing the first silk-screen printing operation on the surface of the semi-finished circuit board 100 by using the screen plate 200 with blocking points, the method further includes:

and step S11, performing acid washing, board grinding, water washing and drying on the surface of the semi-finished circuit board 100.

Because oxide or dirt is remained on the surface of the semi-finished circuit board 100, the surface of the semi-finished circuit board 100 is sequentially subjected to acid washing, board grinding, water washing and drying operations, so that a clean semi-finished circuit board 100 can be obtained, and the bonding force between subsequent ink and the surface of the circuit board can be improved.

The invention also provides a circuit board, wherein the circuit board is provided with the through hole 10, the surface of the circuit board, which is not provided with the through hole 10, is provided with a solder mask, and the solder mask is manufactured by the manufacturing method of the solder mask of the circuit board. The solder mask layer covers the periphery of the through hole 10 and does not enter the through hole 10, and special insulation requirements and heat dissipation requirements of partial products can be met.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention, and all modifications and equivalents of the present invention, which are made by the contents of the present specification and the accompanying drawings, or directly/indirectly applied to other related technical fields, are included in the scope of the present invention.