Method for manufacturing solder mask layer of thick copper circuit board and thick copper circuit board

Abstract

The invention relates to the technical field of printed circuit board manufacturing, in particular to a thick copper circuit board solder mask manufacturing method and a thick copper circuit board, and the thick copper circuit board solder mask manufacturing method comprises the steps that first damming ink is printed on a substrate for the Nth time, a conductive part is arranged on the substrate, and the first damming ink printed for the Nth time is arranged along the edge of the conductive part; the first damming ink printed for the Nth time is subjected to curing treatment; second damming ink is printed on the substrate for the Nth time, and the gap between the conductive part and the first damming ink printed for the Nth time is filled with the second damming ink printed for the Nth time; and the second damming ink printed for the Nth time is subjected to curing treatment. According to the manufacturing method of the solder mask layer of the thick copper circuit board and the thick copper circuit board provided by the invention, the problems that the thickness of the solder mask ink on the circuit surface is thin and the ink is not uniform after the solder mask ink is printed on the surface of the thick copper circuit board through an ink-jet printer in the prior art can be solved.

Description

Technical Field

[0001] The present application relates to the technical field of printed circuit board manufacturing, and in particular to a method for manufacturing a solder mask layer of a thick copper circuit board and a thick copper circuit board. Background Art

[0002] Printed Circuit Board (PCB) is an important electronic component. In the manufacturing process of printed circuit boards, in order to protect the circuits on them and improve their insulation performance, the circuits and some conductive parts need to be protected with solder mask (solder mask ink). Traditional solder mask production processes generally include screen printing, spraying and roller coating, etc. These processes require relatively cumbersome pre-baking, exposure and development processes, low production efficiency and difficult to control product quality. Therefore, the method of using inkjet printing technology to make solder mask came into being.

[0003] The method of making solder mask using inkjet printing technology refers to printing solder mask ink on the surface of printed circuit board through a special inkjet printer, so that it has the same function as traditional solder mask. Inkjet printing technology does not require pre-baking, exposure and development processes, and has many significant advantages such as high efficiency and environmental protection.

[0004] In the related art, after the solder resist ink is printed on the surface of the thick copper circuit board by an inkjet printer, the solder resist ink on the circuit surface is thin and the ink is uneven. Therefore, it is necessary to improve the existing technology. Summary of the invention

[0005] The present application provides a method for manufacturing a solder mask layer of a thick copper circuit board and a thick copper circuit board, which can improve the problem in the related art that after the solder mask ink is printed on the surface of the thick copper circuit board by an inkjet printer, the solder mask ink on the circuit surface is thin and the ink is uneven.

[0006] In a first aspect, an embodiment of the present application provides a method for manufacturing a solder mask layer of a thick copper circuit board, comprising:

[0007] Printing a first damming ink for the Nth time on a substrate, wherein a conductive portion is provided on the substrate, the first damming ink printed for the Nth time is arranged along an edge of the conductive portion, and the first damming ink printed for the Nth time is arranged at an interval from the conductive portion, wherein N is a positive integer greater than or equal to 1;

[0008] Performing a curing process on the first damming ink printed for the Nth time;

[0009] printing a second dam building ink on the substrate for an Nth time, wherein the second dam building ink printed for the Nth time fills a gap between the conductive portion and the first dam building ink printed for the Nth time;

[0010] The second damming ink printed for the Nth time is cured.

[0011] In some embodiments, after printing the second dam building ink on the substrate for the Nth time, a solder resist ink is disposed on the substrate, and the solder resist ink covers the conductive part, the first dam building ink and the second dam building ink.

[0012] In some embodiments, when the second damming ink is printed on the substrate for the Nth time, part of the second damming ink covers the first damming ink printed for the Nth time.

[0013] In some embodiments, after curing the second damming ink printed for the Nth time, the method for manufacturing the solder resist layer further includes:

[0014] Printing the first dam-building ink for the N+1th time on the substrate, the first dam-building ink printed for the N+1th time is arranged along the edge of the conductive portion, the first dam-building ink printed for the N+1th time is located above the first dam-building ink printed for the Nth time and / or the second dam-building ink printed for the Nth time, and the conductive portion is spaced apart from the first dam-building ink printed for the N+1th time;

[0015] Curing the first damming ink printed for the N+1th time;

[0016] Printing a second dam building ink for the N+1th time on the substrate, wherein the first dam building ink printed for the N+1th time is located above the first dam building ink printed for the N+1th time and / or the second dam building ink printed for the Nth time, and the second dam building ink printed for the N+1th time fills a gap between the conductive portion and the first dam building ink printed for the N+1th time;

[0017] The second damming ink printed for the N+1th time is cured.

[0018] In some embodiments, after printing the second dam building ink on the substrate for the N+1th time, a solder resist ink is disposed on the substrate, and the solder resist ink covers the conductive portion, the first dam building ink and the second dam building ink.

[0019] In some embodiments, after printing the second dam building ink on the substrate for the Nth time, the sum of the thickness of the first dam building ink and the thickness of the second dam building ink is greater than or equal to half of the thickness of the conductive portion and less than or equal to the thickness of the conductive portion.

[0020] In some embodiments, the distance between the first damming ink and the conductive portion is 0.1 mm-0.2 mm.

[0021] In some of the embodiments, the conductive portion includes a conductive circuit and / or a conductive pad.

[0022] In some of the embodiments, when the first dam building ink is printed on the substrate for the Nth time, the temperature of the first dam building ink is 30°C-40°C; and / or, when the second dam building ink is printed on the substrate for the Nth time, the temperature of the second dam building ink is 30°C-40°C.

[0023] In a second aspect, an embodiment of the present application provides a thick copper circuit board, which is manufactured by the solder resist manufacturing method as described in the first aspect.

[0024] The method for manufacturing a solder mask layer of a thick copper circuit board provided in an embodiment of the present application has the beneficial effect that: since the first dam building ink is first printed on the substrate for the Nth time and the first dam building ink is cured, and the first dam building ink printed for the Nth time is arranged along the edge of the conductive portion, and the first dam building ink printed for the Nth time is spaced apart from the conductive portion, and then the second dam building ink is printed on the substrate for the Nth time and the second dam building ink is cured, the second dam building ink printed for the Nth time fills the gap between the conductive portion and the first dam building ink printed for the Nth time, so when the second dam building ink is printed on the substrate for the Nth time, the cured first dam building ink printed for the Nth time can prevent the second dam building ink printed for the Nth time from flowing to other positions of the substrate.

[0025] Furthermore, after printing the second dam building ink on the substrate for the Nth time and curing the second dam building ink, the first dam building ink printed for the Nth time and the second dam building ink printed for the Nth time can transition between the surface of the conductive part away from the substrate and the board surface of the substrate and can cover part of the conductive part, thereby avoiding the problem that when solder resist ink is subsequently set on the substrate, the solder resist ink flows quickly to other positions of the substrate due to the large height difference between the surface of the conductive part away from the substrate and the board surface of the substrate, thereby causing the solder resist ink on the conductive part to be thin and the corners of the conductive part to be exposed. The method for manufacturing a solder resist layer of a thick copper circuit board provided in the embodiment of the present application can make the solder resist ink on the substrate more uniform.

[0026] The beneficial effects of the thick copper circuit board provided in the present application compared with the prior art can be referred to the description of the beneficial effects of the solder mask manufacturing method of the thick copper circuit board provided in the present application compared with the prior art, which will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0028] Figure 1 This is a flow chart of a method for manufacturing a solder mask layer of a thick copper circuit board in one of the embodiments of the present application;

[0029] Figure 2 This is a schematic diagram of the structure of a thick copper circuit board in one of the embodiments of the present application;

[0030] Figure 3 is a schematic diagram of the structure of a thick copper circuit board in another embodiment of the present application;

[0031] Figure 4 is a schematic diagram of the structure of a thick copper circuit board in another embodiment of the present application;

[0032] Figure 5 is a schematic structural diagram of a thick copper circuit board in another embodiment of the present application;

[0033] Figure 6 yes Figure 5 A top view of a thick copper circuit board is shown.

[0034] The meanings of the marks in the figure are:

[0035] 10. Substrate; 11. Window area; 20. Conductive part; 30. First dam-building ink; 40. Second dam-building ink; 50. Solder resist ink; 51. Window; 60. Solder pad. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0037] 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 indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0038] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0039] References to "one embodiment", "some embodiments" or "an embodiment" described in the specification of this application mean that a particular feature, structure or characteristic described in conjunction with the embodiment is included in one or more embodiments of the present application. Thus, the phrases "in one embodiment", "in some other embodiments", "in some other embodiments", etc., which appear at different places in this specification, do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. In addition, in one or more embodiments, particular features, structures or characteristics may be combined in any suitable manner.

[0040] In order to illustrate the technical solution of the present application, a description is given below with reference to specific drawings and embodiments.

[0041] The method of making solder mask using inkjet printing technology refers to printing solder mask ink on the surface of printed circuit board through a special inkjet printer, so that it has the same function as traditional solder mask. Inkjet printing technology does not require pre-baking, exposure and development processes, and has many significant advantages such as high efficiency and environmental protection.

[0042] In the related art, after the solder resist ink is printed on the surface of the thick copper circuit board by an inkjet printer, due to the certain fluidity of the solder resist ink, the height difference at the corners of the circuit or the corners of the pad of the thick copper circuit board is large, and the solder resist ink will flow away quickly. Therefore, it is easy to have problems such as the solder resist ink thickness on the circuit or the pad being thin, and the copper being exposed and red at the corners of the circuit or the corners of the pad (the actual solder resist ink thickness is 4.5μm-7.5μm, which does not meet the requirement of the minimum ink thickness of 10μm), resulting in uneven solder resist ink on the circuit surface. Therefore, it is necessary to improve the existing technology.

[0043] The present application provides a method for manufacturing a solder mask layer of a thick copper circuit board and a thick copper circuit board. Since a first dam building ink is printed on a substrate for the Nth time and the first dam building ink is cured, and the first dam building ink printed for the Nth time is arranged along the edge of the conductive portion, and the first dam building ink printed for the Nth time is spaced apart from the conductive portion, and then a second dam building ink is printed on the substrate for the Nth time and the second dam building ink is cured, the second dam building ink printed for the Nth time fills the gap between the conductive portion and the first dam building ink printed for the Nth time. Therefore, when the second dam building ink is printed on the substrate for the Nth time, the cured first dam building ink printed for the Nth time can prevent the second dam building ink printed for the Nth time from flowing to other positions of the substrate.

[0044] Furthermore, after printing the second dam building ink on the substrate for the Nth time and curing the second dam building ink, the first dam building ink printed for the Nth time and the second dam building ink printed for the Nth time can transition between the surface of the conductive part away from the substrate and the board surface of the substrate and can cover part of the conductive part, thereby avoiding the problem that when solder resist ink is subsequently set on the substrate, the solder resist ink flows quickly to other positions of the substrate due to the large height difference between the surface of the conductive part away from the substrate and the board surface of the substrate, thereby causing the solder resist ink on the conductive part to be thin and the corners of the conductive part to be exposed. The method for manufacturing a solder resist layer of a thick copper circuit board provided in the embodiment of the present application can make the solder resist ink on the substrate more uniform.

[0045] Please refer to Figure 1 and Figure 2 , Figure 1 This is a flow chart of a method for making a solder mask layer of a thick copper circuit board in one embodiment of the present application. Figure 2 This is a schematic diagram of the structure of a thick copper circuit board in one of the embodiments of the present application.

[0046] In a first aspect, an embodiment of the present application provides a method for manufacturing a solder mask layer of a thick copper circuit board, comprising:

[0047] S100: Printing the first dam building ink 30 for the Nth time on the substrate 10, a conductive part 20 is provided on the substrate 10, the first dam building ink 30 printed for the Nth time is arranged along the edge of the conductive part 20, and the first dam building ink 30 printed for the Nth time is arranged spaced from the conductive part 20, and N is a positive integer greater than or equal to 1.

[0048] Specifically, the substrate 10 may be subjected to processes such as cutting, drilling, hole metallization, electroplating, and outer layer circuit production.

[0049] Cutting: Cut the large sheet material into substrates 10 of specified size according to the production panel size requirements.

[0050] Drilling: drilling holes in the cut substrate 10.

[0051] Hole metallization and electroplating: After drilling, the hole metallization process is carried out to make the hole wall conductive. The metallized through holes of all layers can be processed by copper deposition and electroplating.

[0052] Outer layer circuit production: Use mask etching process to complete the transfer of outer layer graphic circuits.

[0053] The first damming ink 30 may be printed on the substrate 10 by an inkjet printer, and the first damming ink 30 may be solder resist printing ink. The conductive part 20 includes a conductive circuit and / or a conductive pad, and the conductive layer may be made of copper, silver or aluminum.

[0054] Among them, the graphics produced by the project need to be converted in advance before inkjet printing by inkjet printer, and the CAD / CAM vector graphics produced by the project, usually in Gerber RS-274x format, are converted into pixel bitmaps, also known as raster. This conversion is completed by the software of the raster image processor (RIP). The raster image processor receives the input vector file and various conversion parameters. The design will be rasterized on a denser grid. The resolution of the grid is limited to the minimum resolution required for the droplet overlap to form a closed layer and the required resolution of the printed material. The resolution is usually 1000dpi and above to ensure the accuracy of the feature size of the printed graphics.

[0055] The Gerber (vector) file data in the system will be transferred from the host computer to the inkjet printing system and converted into a printable bitmap file. When the substrate 10 is loaded into the inkjet printer, it will be automatically aligned by a CCD (Charge Coupled Device) camera, and then the first dam-building ink 30 will be printed on the substrate 10 by jet printing, and can be cured at the same time as printing.

[0056] Since the thickness of the conductive portion 20 of the thick copper circuit board is generally large, the height difference between the surface of the conductive portion 20 away from the substrate 10 and the board surface of the substrate 10 is large.

[0057] In this embodiment, the conductive part 20 is a conductive circuit made of copper, and the thickness of the conductive part 20 is 2 oz, which is about 70 μm.

[0058] S200: curing the first dam-building ink 30 printed for the Nth time.

[0059] Specifically, the first dam-building ink 30 can be cured by a LED-UV (Light-Emitting Diode-Ultraviolet) light curing machine provided in the inkjet printer.

[0060] The UV-LED light curing machine is a device that uses an ultraviolet LED light source to irradiate UV photosensitive materials to quickly cure them. The light source is a cold light source, which does not generate heat radiation and does not cause thermal damage to the substrate 10. The LED-UV light uses a 395nm wavelength light source, and the curing energy is 1000mj-1500mj. When the ultraviolet light emitted by the LED-UV light curing machine irradiates the surface of the first dam building ink 30, the photosensitive substance in the first dam building ink 30 absorbs the light energy and excites, thereby initiating a chemical reaction. This chemical reaction will cause the monomers or molecules in the first dam building ink 30 to form crosslinks, and quickly transform the first dam building ink 30 from a liquid or semi-solid state to a solid state. The LED-UV light can use a 395nm wavelength light source, and the curing energy is 1000mj-1500mj.

[0061] S300 : printing the second dam building ink 40 on the substrate 10 for the Nth time, and the second dam building ink 40 printed for the Nth time fills the gap between the conductive part 20 and the first dam building ink 30 printed for the Nth time.

[0062] Specifically, the second damming ink 40 may be printed on the substrate 10 by an inkjet printer, and the second damming ink 40 may be solder resist printing ink.

[0063] It is understandable that, since the first dam building ink 30 has been printed on the substrate 10 and cured, when the second dam building ink 40 is printed on the substrate 10, the second dam building ink 40 will be blocked by the cured first dam building ink 30, preventing the second dam building ink 40 from flowing to other positions of the substrate 10.

[0064] S400: curing the second dam-building ink 40 printed for the Nth time.

[0065] Specifically, the second dam-building ink 40 can be cured by a LED-UV light curing machine provided in the inkjet printer.

[0066] From the above, it can be seen that in the method for manufacturing the solder mask layer of the thick copper circuit board provided in the embodiment of the present application, since the first dam building ink 30 is first printed on the substrate 10 for the Nth time and the first dam building ink 30 is cured, and the first dam building ink 30 printed for the Nth time is arranged along the edge of the conductive portion 20, and the first dam building ink 30 printed for the Nth time is spaced apart from the conductive portion 20, and then the second dam building ink 40 is printed on the substrate 10 for the Nth time and the second dam building ink 40 is cured, the second dam building ink 40 printed for the Nth time fills the gap between the conductive portion 20 and the first dam building ink 30 printed for the Nth time, so when the second dam building ink 40 is printed on the substrate 10 for the Nth time, the cured first dam building ink 30 printed for the Nth time can prevent the second dam building ink 40 printed for the Nth time from flowing to other positions of the substrate 10.

[0067] Furthermore, after the second dam building ink 40 is printed on the substrate 10 for the Nth time and the second dam building ink 40 is cured, the first dam building ink 30 printed for the Nth time and the second dam building ink 40 printed for the Nth time can transition between the surface of the conductive part 20 away from the substrate 10 and the board surface of the substrate 10 and can cover part of the conductive part 20, thereby avoiding the problem that when the solder resist ink 50 is subsequently set on the substrate 10, the solder resist ink 50 quickly flows to other positions of the substrate 10 due to the large height difference between the surface of the conductive part 20 away from the substrate 10 and the board surface of the substrate 10, thereby causing the solder resist ink 50 on the conductive part 20 to be thin and the corners of the conductive part 20 to be exposed. The solder resist layer manufacturing method of the thick copper circuit board provided in the embodiment of the present application can make the solder resist ink 50 on the substrate 10 more uniform.

[0068] The method for manufacturing the solder mask layer of the thick copper circuit board provided in the embodiment of the present application can ensure the thickness of the solder mask ink 50 on the surface of the thick copper circuit board, thereby avoiding the problems of high voltage spark short circuit and circuit corrosion on the thick copper circuit board.

[0069] Optionally, before printing the first dam-building ink 30 on the substrate 10 for the Nth time, the substrate 10 is subjected to an ultra-roughening and anti-penetration process, the specific process of which is: pickling, grinding, water washing, ultra-roughening, water washing, hydrochloric acid washing, water washing, anti-penetration-water washing, and drying.

[0070] The function of pickling is to remove oxides on the surface of the substrate 10;

[0071] The function of the grinding plate is to remove dirt on the surface of the substrate 10 by means of a mechanical grinding brush to ensure that the surface is clean.

[0072] The function of the super-roughening is to roughen the surface of the copper conductive circuit to form a honeycomb shape, thereby increasing the surface area of ​​the conductive circuit and further increasing the bonding force between the conductive circuit and the first dam-building ink 30 , the second dam-building ink 40 and the solder resist ink 50 .

[0073] The hydrochloric acid washing is to clean the residual super-roughening solution on the surface of the conductive circuit.

[0074] The reason for the super-roughening and anti-penetration treatment is that the ink droplets ejected by the inkjet printer are spherical in shape, but the shape of the ink droplets falling on the substrate 10 is not spherical. Due to the gravity of the ink droplets themselves and the surface material of the substrate, the ink droplets will penetrate all around, and the extent of penetration depends on the size of the ink droplets and the surface roughness of the substrate. In order to obtain high-resolution graphics, the ink droplets must penetrate as little as possible on the substrate, and at the same time, the bonding force between the ink and the substrate surface must be ensured. Therefore, for the solder mask inkjet of the circuit board, anti-penetration treatment is required, and the combination of anti-penetration treatment and super-roughening can reduce the impact of the printing ink penetration problem while ensuring the bonding force.

[0075] The anti-penetration treatment is to reduce the ink penetration phenomenon by reducing the surface energy (increasing the contact angle). It is completed after the super-roughening. The anti-penetration solution treats the substrate 10 at room temperature for 15sec-20sec, which can control the surface contact angle of the conductive circuit to 75°-85°, and the ink diffusion amount can be controlled within 25μm. The roughness of the substrate 10 after the anti-penetration treatment is not affected, which can ensure the bonding strength between the conductive circuit and the ink.

[0076] Please refer to Figure 2 In this embodiment, after the second dam building ink 40 is printed on the substrate 10 for the Nth time, a solder resist ink 50 is disposed on the substrate 10 , and the solder resist ink 50 covers the conductive part 20 , the first dam building ink 30 and the second dam building ink 40 .

[0077] By adopting the above solution, it is possible to avoid the problem that when the solder resist ink 50 is set on the substrate 10, the solder resist ink 50 quickly flows to other positions of the substrate 10 due to the large height difference between the surface of the conductive part 20 away from the substrate 10 and the board surface of the substrate 10, thereby causing the solder resist ink 50 on the conductive part 20 to be thin and the corners of the conductive part 20 to be exposed.

[0078] It is understandable that the solder resist ink 50 can be printed on the substrate 10 by an inkjet printer. After the solder resist ink 50 is set on the substrate 10, the solder resist ink 50 can be cured, such as by curing the solder resist ink 50 with an LED-UV light curing machine provided in the inkjet printer, or by baking the substrate 10 at a high temperature to cause a polymer polymerization reaction in the solder resist ink 50, thereby achieving the effect of the solder resist ink 50 protecting the circuit, improving the insulation performance, and preventing moisture and chemical corrosion.

[0079] After setting the solder resist ink 50 on one side of the substrate 10, the substrate 10 can be turned over manually or automatically, and the camera positioning is performed again to start printing the solder resist ink 50 on the other side. After completing the above operations, the substrate 10 is taken out of the inkjet printer, inserted into the plug-in steel frame, and finally heat-baked at 150° C. for 60 minutes to achieve the purpose of final curing.

[0080] Among them, high temperature baking needs to be carried out in stages. 150°C is the final curing temperature of solder resist ink 50. Baking at this temperature for 60 minutes can ensure that the curing rate of solder resist ink 50 reaches the best, while making the electrical properties and chemical corrosion resistance of thick copper circuit boards reach the best.

[0081] It can be understood that in this embodiment, the conductive part 20 includes a conductive circuit, and neither the first dam building ink 30 nor the second dam building ink 40 covers the surface of the conductive circuit away from the substrate 10 , and only the solder resist ink 50 covers the surface of the conductive circuit away from the substrate 10 .

[0082] Please refer to Figure 4 , Figure 4 It is a schematic diagram of the structure of a thick copper circuit board in another embodiment of the present application.

[0083] In yet another embodiment, the conductive portion 20 includes a conductive pad, and the first damming ink 30 , the second damming ink 40 and the solder resist ink 50 may only cover a portion of the surface of the conductive pad away from the substrate 10 .

[0084] Please refer to Figure 2 In this embodiment, the solder resist ink 50 is disposed on the substrate 10, including: printing the solder resist ink 50 on the substrate 10 multiple times until the total thickness of the solder resist ink 50 reaches a preset thickness.

[0085] Such an arrangement can make the solder resist ink 50 more evenly distributed.

[0086] By way of example, the solder resist ink 50 is printed on the substrate 10 4 to 6 times.

[0087] Optionally, when the second dam building ink 40 is printed on the substrate 10 for the Nth time, part of the second dam building ink 40 covers the first dam building ink 30 printed for the Nth time.

[0088] With such a configuration, when the solder resist ink 50 is disposed on the substrate 10 , the solder resist ink 50 is distributed more evenly without any unevenness.

[0089] It can be understood that the thickness of the second dam building ink 40 is greater than the thickness of the first dam building ink 30. When the second dam building ink 40 is printed on the substrate 10 for the Nth time, part of the second dam building ink 40 is first used to fill the gap between the conductive part 20 and the first dam building ink 30 printed for the Nth time, and then part of the second dam building ink 40 printed for the Nth time is used to cover the first dam building ink 30 printed for the Nth time.

[0090] Optionally, after printing the second dam building ink 40 on the substrate 10 for the Nth time, the sum of the thickness of the first dam building ink 30 and the thickness of the second dam building ink 40 is greater than or equal to one half of the thickness of the conductive portion 20 and less than or equal to the thickness of the conductive portion 20 .

[0091] By adopting the above scheme, the first dam building ink 30 and the second dam building ink 40 can be used to effectively transition the surface of the conductive part 20 away from the substrate 10 and the board surface of the substrate 10 and can cover part of the conductive part 20, thereby avoiding the problem that when the solder resist ink 50 is subsequently set on the substrate 10, the solder resist ink 50 quickly flows to other positions of the substrate 10 due to the large height difference between the surface of the conductive part 20 away from the substrate 10 and the board surface of the substrate 10, thereby causing the solder resist ink 50 on the conductive part 20 to be thin and the corners of the conductive part 20 to be exposed, and the printing efficiency of the first dam building ink 30 and the second dam building ink 40 is improved.

[0092] Optionally, the distance between the first damming ink 30 and the conductive part 20 is 0.1 mm-0.2 mm.

[0093] Such an arrangement can ensure that when the second dam building ink 40 is printed on the substrate 10 , the solidified first dam building ink 30 can prevent the second dam building ink 40 from flowing to other positions of the substrate 10 .

[0094] Optionally, the distance between the first damming ink 30 and the conductive part 20 is 0.1 mm-0.2 mm.

[0095] Such an arrangement can ensure that when the second dam building ink 40 is printed on the substrate 10 , the solidified first dam building ink 30 can prevent the second dam building ink 40 from flowing to other positions of the substrate 10 .

[0096] Optionally, in some embodiments, when the first dam building ink 30 is printed on the substrate 10, the temperature of the first dam building ink 30 is 30°C-40°C; and / or, when the second dam building ink 40 is printed on the substrate 10, the temperature of the second dam building ink 40 is 30°C-40°C.

[0097] By adopting the above solution, the first dam building ink 30 and the second dam building ink 40 can have better fluidity and meet the quality requirements.

[0098] For example, when the first dam building ink 30 is printed on the substrate 10, the temperature of the first dam building ink 30 is 35°C; when the second dam building ink 40 is printed on the substrate 10, the temperature of the second dam building ink 40 is 35°C. At this temperature, the viscosity of the first dam building ink 30 and the viscosity of the second dam building ink 40 are both 8mPa.s-10mPa.s. The ink with this viscosity has the best fluidity, which can make the solder mask ink 50 have a smooth appearance and meet the quality requirements.

[0099] During normal inkjet printing, the maximum fluidity of the ink is 0.025 mm, and the precision of the inkjet printer is 0.025 mm. Therefore, when the solder resist ink 50 is disposed on the substrate 10 , the solder resist ink 50 may flow to the window area 11 of the substrate 10 .

[0100] Please refer to Figure 5 and Figure 6 , Figure 5 This is a schematic diagram of the structure of a thick copper circuit board in another embodiment of the present application. Figure 6 yes Figure 5 A top view of a thick copper circuit board is shown.

[0101] In another embodiment, the substrate 10 includes a window area 11; before setting the solder resist ink 50 on the substrate 10 by printing, it is necessary to ensure that the distance between the edge of the ink printing pattern and the window area 11 is greater than or equal to 0.05 mm to prevent the solder resist ink 50 from flowing to the window area 11 during printing.

[0102] It can be understood that after the solder resist ink 50 is cured, the solder resist ink 50 forms a window 51 exposing the window area 11 .

[0103] It should be noted that the window area 11 does not need to be covered with the solder resist ink 50 , and the window area 11 may be provided with a solder pad 60 or a plug-in hole, etc.

[0104] It should also be noted that when the distance between the edge of the ink printed pattern and the window area 11 is less than 0.05 mm, the printed pattern of the welding pad 60 or the plug-in hole in the window area 11 can be overlapped using CAM software.

[0105] Please refer to Figure 2 In this embodiment, after the second damming ink 40 printed for the Nth time is cured, the solder resist manufacturing method further includes:

[0106] First, the first dam building ink 30 is printed on the substrate 10 for the N+1th time, and the first dam building ink 30 printed for the N+1th time is arranged along the edge of the conductive part 20. The first dam building ink 30 printed for the N+1th time is located above the first dam building ink 30 printed for the Nth time and / or the second dam building ink 40 printed for the Nth time, and the conductive part 20 is spaced apart from the first dam building ink 30 printed for the N+1th time.

[0107] Next, the first dam-building ink 30 printed for the N+1th time is cured.

[0108] Again, the second dam building ink 40 is printed on the substrate 10 for the N+1th time, the first dam building ink printed for the N+1th time is located above the first dam building ink 30 printed for the N+1th time and / or the second dam building ink 40 printed for the N+1th time, and the second dam building ink 40 printed for the N+1th time fills the gap between the conductive part 20 and the first dam building ink 30 printed for the N+1th time.

[0109] Then, the second damming ink 40 printed for the N+1th time is cured.

[0110] By adopting the above scheme, the first dam building ink 30 and the second dam building ink 40 can be used to transition between the surface of the conductive part 20 away from the substrate 10 and the board surface of the substrate 10 and can cover part of the conductive part 20, thereby avoiding the problem that when the solder resist ink 50 is subsequently set on the substrate 10, the solder resist ink 50 quickly flows to other positions of the substrate 10 due to the large height difference between the surface of the conductive part 20 away from the substrate 10 and the board surface of the substrate 10, thereby causing the solder resist ink 50 on the conductive part 20 to be thin and the corners of the conductive part 20 to be exposed.

[0111] It can be understood that after the second dam building ink 40 printed for the N+1th time is cured, the sum of the total thickness of the first dam building ink 30 and the total thickness of the second dam building ink 40 is greater than or equal to half of the thickness of the conductive part 20 and less than or equal to the thickness of the conductive part 20.

[0112] Optionally, after the second dam building ink 40 is printed on the substrate 10 for the N+1th time, a solder resist ink 50 is disposed on the substrate 10 , and the solder resist ink 50 covers the conductive part 20 , the first dam building ink 30 and the second dam building ink 40 .

[0113] Such a configuration can avoid the problem that when the solder resist ink 50 is set on the substrate 10, the solder resist ink 50 quickly flows to other positions of the substrate 10 due to the large height difference between the surface of the conductive part 20 away from the substrate 10 and the board surface of the substrate 10, thereby causing the solder resist ink 50 on the conductive part 20 to be thin and the corners of the conductive part 20 to be exposed.

[0114] For example, please refer to Figure 3 , Figure 3 It is a schematic diagram of the structure of a thick copper circuit board in another embodiment of the present application.

[0115] If the thickness of the conductive part 20 is too large, after the second dam building ink 40 is cured, the first dam building ink 30 and the second dam building ink 40 can be continuously printed on the substrate 10 and cured until the sum of the thickness of the first dam building ink 30 and the thickness of the second dam building ink 40 meets the requirement.

[0116] First, the first dam building ink 30 is printed on the substrate 10 for the first time and then the first dam building ink 30 is cured.

[0117] Next, the second dam building ink 40 is printed on the substrate 10 for the first time and then cured. The second dam building ink 40 is filled with the gap between the first dam building ink 30 and the conductive part 20 .

[0118] Again, the first dam building ink 30 is printed on the substrate 10 for a second time. The first dam building ink 30 printed for the second time may be located above the first dam building ink 30 printed for the first time and / or the second dam building ink 40 printed for the first time. The first dam building ink 30 printed for the second time is spaced apart from the conductive part 20 with a gap therebetween.

[0119] Then, the second dam building ink 40 is printed on the substrate 10 for a second time and is cured. The second dam building ink 40 printed for the second time may be located above the first dam building ink 30 printed for the second time and / or the second dam building ink 40 printed for the first time, and the second dam building ink 40 printed for the second time fills the gap between the first dam building ink 30 printed for the second time and the conductive part.

[0120] The above steps are repeated until the sum of the thickness of the first dam building ink 30 and the thickness of the second dam building ink 40 meets the requirements, that is, a smooth transition can be made between the surface of the conductive part 20 away from the substrate 10 and the board surface of the substrate 10 and a part of the conductive part can be covered, thereby avoiding a large height difference between the surface of the conductive part 20 away from the substrate 10 and the board surface of the substrate 10, which causes the solder resist ink 50 to flow quickly to other positions of the substrate 10, thereby causing the solder resist ink 50 on the conductive part 20 to be thin and the corners of the conductive part 20 to be exposed.

[0121] It should be noted that, in other embodiments, if the thickness of the conductive part 20 is too large, after the second dam building ink 40 is cured, the solder resist ink 50 may be firstly arranged on the substrate 10, and the first dam building ink 30 and the second dam building ink 40 may be printed on the substrate 10 again and cured, and then the solder resist ink 50 may be arranged on the substrate 10 again, and the above process may be repeated until the sum of the thickness of the first dam building ink 30, the thickness of the second dam building ink 40 and the thickness of the solder resist ink 50 meets the requirements.

[0122] In a second aspect, an embodiment of the present application provides a thick copper circuit board, which is manufactured by the solder mask manufacturing method of the first aspect.

[0123] In the method for manufacturing a solder mask layer of a thick copper circuit board provided in an embodiment of the present application, the first dam building ink 30 is first printed on the substrate 10 for the Nth time and the first dam building ink 30 is cured, and the first dam building ink 30 printed for the Nth time is arranged along the edge of the conductive portion 20, and the first dam building ink 30 printed for the Nth time is spaced apart from the conductive portion 20, and then the second dam building ink 40 is printed on the substrate 10 for the Nth time and the second dam building ink 40 is cured, and the second dam building ink 40 printed for the Nth time fills the gap between the conductive portion 20 and the first dam building ink 30 printed for the Nth time. Therefore, when the second dam building ink 40 is printed on the substrate 10 for the Nth time, the cured first dam building ink 30 printed for the Nth time can prevent the second dam building ink 40 printed for the Nth time from flowing to other positions of the substrate 10.

[0124] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A method for manufacturing a solder mask layer of a thick copper circuit board, characterized in that: include: Printing a first damming ink for the Nth time on a substrate, wherein a conductive portion is provided on the substrate, the first damming ink printed for the Nth time is arranged along an edge of the conductive portion, and the first damming ink printed for the Nth time is arranged at an interval from the conductive portion, wherein N is a positive integer greater than or equal to 1; Performing a curing process on the first damming ink printed for the Nth time; printing a second dam building ink on the substrate for an Nth time, wherein the second dam building ink printed for the Nth time fills a gap between the conductive portion and the first dam building ink printed for the Nth time; The second damming ink printed for the Nth time is cured.

2. The method for making a solder mask layer according to claim 1, wherein: After printing the second dam building ink on the substrate for the Nth time, a solder resist ink is disposed on the substrate, and the solder resist ink covers the conductive portion, the first dam building ink and the second dam building ink.

3. The method for making a solder mask layer according to claim 2, wherein: When the second damming ink is printed on the substrate for the Nth time, part of the second damming ink covers the first damming ink printed for the Nth time.

4. The method for making a solder mask layer according to claim 1, wherein: After curing the second damming ink printed for the Nth time, the solder resist manufacturing method further includes: Printing the first dam-building ink for the N+1th time on the substrate, the first dam-building ink printed for the N+1th time is arranged along the edge of the conductive portion, the first dam-building ink printed for the N+1th time is located above the first dam-building ink printed for the Nth time and / or the second dam-building ink printed for the Nth time, and the conductive portion is spaced apart from the first dam-building ink printed for the N+1th time; Curing the first damming ink printed for the N+1th time; Printing a second dam building ink for the N+1th time on the substrate, wherein the first dam building ink printed for the N+1th time is located above the first dam building ink printed for the N+1th time and / or the second dam building ink printed for the Nth time, and the second dam building ink printed for the N+1th time fills a gap between the conductive portion and the first dam building ink printed for the N+1th time; The second damming ink printed for the N+1th time is cured.

5. The method for making a solder mask layer according to claim 4, wherein: After printing the second dam building ink on the substrate for the N+1th time, a solder resist ink is disposed on the substrate, and the solder resist ink covers the conductive portion, the first dam building ink and the second dam building ink.

6. The method for making a solder mask layer according to claim 1, wherein: After printing the second dam building ink on the substrate for the Nth time, the sum of the thickness of the first dam building ink and the thickness of the second dam building ink is greater than or equal to half of the thickness of the conductive portion and less than or equal to the thickness of the conductive portion.

7. The method for making a solder mask layer according to claim 1, wherein: The distance between the first dam-building ink and the conductive part is 0.1 mm-0.2 mm.

8. The method for manufacturing a solder mask layer according to any one of claims 1 to 7, characterized in that: The conductive part includes a conductive circuit and / or a conductive pad.

9. The method for manufacturing a solder resist layer according to any one of claims 1 to 7, characterized in that: When the first dam building ink is printed on the substrate for the Nth time, the temperature of the first dam building ink is 30°C-40°C; and / or when the second dam building ink is printed on the substrate for the Nth time, the temperature of the second dam building ink is 30°C-40°C.

10. A thick copper circuit board, characterized in that: The thick copper circuit board is manufactured by the solder resist manufacturing method as claimed in any one of claims 1 to 9.

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