Circuit board manufacturing method and circuit board

Abstract

The invention is applicable to the field of circuit boards, and provides a circuit board manufacturing method, which comprises the following steps: providing a circuit board main body of an outer circuit to be manufactured, the circuit board main body comprising at least one finished product area and a waste material area arranged at the outer side of the finished product area; manufacturing an outer-layer circuit on the surface of the circuit board main body, and manufacturing a plurality of outer-layer metal patterns distributed at intervals in the waste material area; printing ink on the surface of the circuit board main body; exposing and developing the ink to form a solder mask layer; and removing the waste material area to obtain the circuit board. According to the circuit board manufacturing method provided by the embodiment of the invention, a plurality of spaced outer-layer metal patterns are manufactured in the waste area while the outer-layer circuit is manufactured, so that the flatness of the circuit board main body can be improved, the problem of non-uniform printing ink caused by local oil quantity difference is solved, and the uniformity of the printing ink thickness after the circuit board is subjected to solder mask processing is improved. The invention further provides a circuit board.

Description

Technical Field

[0001] The present application relates to the field of circuit boards, and in particular to a method for manufacturing a circuit board and a circuit board. Background Art

[0002] Currently, high-end substrates are manufactured using arbitrary-layer interconnect technology to meet the ultra-high-density interconnect requirements of modern high-computing chips (such as CPU / GPU / AI chips). With the advancement of arbitrary-layer interconnect technology, the requirements for uniform ink thickness on circuit boards are also gradually increasing.

[0003] The conventional process of solder mask processing for substrates is as follows: solder mask pre-treatment, screen printing, pre-bake, exposure, development, and post-bake. During the screen printing process, due to the thinness of the substrate, problems such as board warping may occur, resulting in differences in the amount of ink applied locally, causing quality defects such as uneven ink thickness. Summary of the Invention

[0004] In view of this, the present application provides a circuit board manufacturing method and a circuit board, which can improve the uniformity of ink thickness after solder mask processing of the circuit board.

[0005] The embodiment of the first aspect of the present application provides a method for manufacturing a circuit board, comprising:

[0006] Providing a circuit board body on which an outer layer circuit is to be manufactured, wherein the circuit board body comprises at least one finished product area and a waste material area provided outside the finished product area;

[0007] Fabricating an outer layer circuit on the surface of the circuit board body, and simultaneously fabricating a plurality of outer layer metal patterns distributed at intervals in the waste area;

[0008] printing ink on the surface of the circuit board body;

[0009] exposing and developing the ink to form a solder resist layer;

[0010] The waste area is removed to obtain a circuit board.

[0011] In some embodiments, the finished product area includes at least one finished product unit and a waiting area adjacent to the finished product unit;

[0012] When the outer layer circuit is produced on the surface of the circuit board body, a plurality of the outer layer metal patterns distributed at intervals are produced in the blank area to be processed.

[0013] In some embodiments, after the outer layer circuits are formed on the surface of the circuit board body, the finished product area is formed with a circuit-intensive area and a substrate area, the outer layer circuits are located in the circuit-intensive area, the surface of the substrate area is not covered with the outer metal layer, and the length and width of the substrate area are both greater than or equal to 3 mm;

[0014] Printing ink on the surface of the circuit board body includes:

[0015] Providing a wire mesh, the wire mesh comprising a first wire mesh portion and a second wire mesh portion, wherein the mesh number of the first wire mesh portion is greater than the mesh number of the second wire mesh portion;

[0016] The screen is placed above the circuit board body so that the first screen portion faces the circuit-dense area and the second screen portion faces the substrate area, and ink is printed on the surface of the circuit board body through the screen.

[0017] In some embodiments, the viscosity of the ink is 125 dPas to 135 dPas, and the screen printing pressure is in the range of 4.5 kg / cm 2 Up to 5.5kg / cm 2 The distance between the silk screen and the circuit board body is 6.5 mm to 7.5 mm.

[0018] In some embodiments, during the step of printing ink on the surface of the circuit board body, the circuit board body is fixed on the electrostatic base plate of the screen printing machine table, and the electrostatic base plate is used to adsorb the circuit board body, so that the orthographic projection of the circuit board body on the screen printing machine table completely falls within the electrostatic base plate.

[0019] In some embodiments, the circuit board body includes multiple inner metal layers, at least one of the inner metal layers is provided with an inner metal pattern in the waste area, and the inner metal pattern and the outer metal pattern are staggered in their orthographic projection on the outer surface of the circuit board body.

[0020] In some embodiments, the spacing of the outer metal patterns is greater than or equal to the minimum line spacing of the outer circuits; and / or,

[0021] The linear size of the outer metal pattern is greater than or equal to the linear size of the smallest pad in the outer circuit.

[0022] In some embodiments, the outer metal pattern is circular or rectangular; wherein the spacing between any two adjacent outer metal patterns is 0.2 mm to 2 mm; and / or the linear dimension of the outer metal pattern is 1.0 mm to 4.0 mm.

[0023] In some embodiments, a plurality of the outer metal patterns are evenly distributed in the waste area.

[0024] An embodiment of the second aspect of the present application provides a circuit board, which is manufactured using the circuit board manufacturing method of the first aspect.

[0025] In the circuit board manufacturing method provided in the embodiment of the present application, in the step of manufacturing the outer layer circuit, multiple outer layer metal patterns distributed at intervals are simultaneously manufactured in the waste area, thereby improving the overall flatness of the circuit board and reducing the warping of the circuit board, thereby improving the flatness of the ink in the printing step and solving the problem of uneven ink application caused by board warping. Therefore, the above-mentioned circuit board manufacturing method can improve the uniformity of the ink thickness after the circuit board solder mask processing, thereby improving the processing quality of the circuit board. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments or descriptions of the prior art. 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 any creative work.

[0027] Figure 1 This is a flow chart of a circuit board manufacturing method provided in one embodiment of the present application;

[0028] Figure 2 This is one of the structural diagrams of a circuit board provided in one embodiment of the present application;

[0029] Figure 3 This is the second structural diagram of the circuit board provided in one embodiment of the present application;

[0030] Figure 4 This is a schematic structural diagram of a finished product area provided in one embodiment of the present application;

[0031] Figure 5 It is a schematic diagram of the partial structure of the screen provided in one embodiment of the present application.

[0032] The meanings of the marks in the figure are:

[0033] 10. Circuit board body;

[0034] 101, finished product area; 1011, finished product unit; 1011a, circuit-intensive area; 1011b, substrate area; 1012, waiting area;

[0035] 102. Waste area;

[0036] 11. Outer metal layer; 111. Outer circuit; 112. Outer metal pattern; 12. Inner metal layer; 121. Inner circuit; 122. Inner metal pattern; 13. Insulation layer; 14. Via hole;

[0037] 20. Solder mask layer;

[0038] 200, wire mesh; 210, first wire mesh portion; 220, second wire mesh portion. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solutions and advantages of this application more clearly understood, the following further describes this application in detail with reference to the accompanying drawings, i.e., embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0040] It should be noted that when a component is referred to as being "fixed on" or "disposed on" another component, it may be directly or indirectly on the other component. When a component is referred to as being "connected to" another component, it may be directly or indirectly connected to the other component. The terms "upper", "lower", "left", "right", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of description and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the patent. The terms "first" and "second" are only used for the convenience of description and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features. "Multiple" means two or more, unless otherwise clearly and specifically defined.

[0041] In order to illustrate the technical solution described in this application, the following description is given with reference to specific drawings and embodiments.

[0042] Arbitrary-layer interconnect technology is a high-end interconnect process in printed circuit board (PCB) manufacturing. Designed specifically to address the need for ultra-high-density wiring, it increases wiring density and optimizes signal performance, facilitating lightweight and high-reliability manufacturing. Some electronic products, such as high-end smartphones, 5G / AI devices, and medical electronics, require high-density wiring, and the PCBs used in these products can be manufactured using arbitrary-layer interconnect technology.

[0043] Currently, high-end carrier boards are manufactured using arbitrary layer interconnection technology to meet the ultra-high density interconnection requirements of modern high-computing power chips (such as CPU / GPU / AI chips).

[0044] With the advancement of arbitrary-layer interconnect technology, the requirements for uniform ink thickness on PCBs are also increasing. The conventional process for substrate solder mask processing includes solder mask pre-treatment, screen printing, pre-bake, exposure, development, and post-bake. During the screen printing process, due to the thinness of the substrate, problems such as board warping can occur, resulting in localized variations in ink application and causing quality defects such as uneven ink thickness.

[0045] In view of this, an embodiment of the present application provides a circuit board manufacturing method, including: providing a circuit board main body, the circuit board main body including at least one finished product area and a waste area arranged outside the finished product area; making an outer layer circuit on the surface of the circuit board main body, and at the same time making a plurality of spaced outer layer metal patterns in the waste area; screen printing ink on the surface of the circuit board main body; exposing and developing the ink to form a solder resist layer; and removing the waste area to obtain a circuit board.

[0046] In the circuit board manufacturing method provided in the embodiment of the present application, during the step of manufacturing the outer layer circuit, a plurality of spaced outer layer metal patterns are simultaneously manufactured in the waste area to improve the overall flatness of the circuit board, reduce the warping of the circuit board, and thereby improve the flatness of the ink in the printing step. Therefore, the above-mentioned circuit board manufacturing method can improve the uniformity of the ink thickness after the circuit board is solder-resistant processed.

[0047] The circuit board provided in the embodiment of the present application may be a circuit board using any layer interconnection technology, but is not limited thereto. The circuit board using any layer interconnection technology may be a carrier board, a high density interconnect board (HDIB), etc.

[0048] The embodiment of the first aspect of the present application provides a method for manufacturing a circuit board. Figures 1 to 3 , the circuit board manufacturing method includes:

[0049] Step S1 : providing a circuit board body 10 on which an outer layer circuit 111 is to be manufactured. The circuit board body 10 includes at least one finished product area 101 and a waste area 102 located outside the finished product area 101 .

[0050] The circuit board body 10 is an intermediate product in the circuit board manufacturing process. In some embodiments, the circuit board body 10 is a motherboard for manufacturing the outer layer circuit 111, that is, the motherboard has completed steps such as manufacturing the inner layer circuit 121; the circuit board body 10 is a multi-layer board, and at least one layer of inner layer circuit 121 is provided in the circuit board body 10.

[0051] The circuit board body 10 includes a finished product area 101 and a scrap area 102. The finished product area 101 is the area used for producing circuit boards, while the scrap area 102 is the area outside the finished product area 101 to be removed. There can be one or more finished product areas 101, each used to produce multiple circuit boards. There can also be one or more scrap areas 102. For example, there can be one scrap area 102 surrounding all finished product areas 101, or multiple scrap areas 102 spaced apart.

[0052] Step S2 : forming an outer layer circuit 111 on the surface of the circuit board body 10 , and forming a plurality of outer layer metal patterns 112 distributed at intervals in the waste area 102 .

[0053] In some embodiments, the surface of the circuit board body 10 is provided with an outer metal layer 11. The outer metal layer 11 is a complete metal layer, that is, the outer metal layer 11 covers both the finished product area 101 and the scrap area 102. Specifically, step S2 comprises first forming a dry film on the surface of the outer metal layer 11, then exposing and developing the circuit board body 10, etching the outer metal layer 11, and then removing the dry film to pattern the outer metal layer 11. This simultaneously forms outer circuits 111 within the finished product area 101 and a plurality of outer metal patterns 112 within the scrap area 102. The outer metal patterns 112 are produced together with the outer circuits 111, without adding additional manufacturing processes. Only the design of the outer metal patterns 112 needs to be added to the circuit exposure data.

[0054] In other embodiments, step S2 may also be performed by simultaneously manufacturing the outer layer circuit 111 and the outer layer metal pattern 112 through electroplating or other methods.

[0055] The outer metal pattern 112 can be shaped like a circle, rectangle, or strip. This allows for a more regular shape and higher manufacturing precision. The outer metal pattern 112 can also be shaped like a fan or a cross. The outer metal layer 11 can be a copper layer, and the outer metal pattern 112 can be a copper pad.

[0056] In the scrap area 102 , a plurality of outer metal patterns 112 are spaced apart. Optionally, the plurality of outer metal patterns 112 may have the same shape and size, and the plurality of outer metal patterns 112 are evenly distributed, but the present invention is not limited thereto.

[0057] Through step S2, an outer layer circuit 111 is produced in the finished product area 101, and multiple outer layer metal patterns 112 are produced in the scrap area 102. In this way, both the finished product area 101 and the scrap area 102 are provided with metal patterns, which reduces the difference between the copper layer and the substrate area 1011b, can improve the flatness of the circuit board body 10, and reduce the warping of the circuit board body 10.

[0058] Step S3: printing ink on the surface of the circuit board body 10 .

[0059] Ink is used to make solder mask, which is a protective coating covering the surface of the circuit. Its core functions include preventing solder short circuits, protecting the copper layer from oxidation and mechanical damage, and providing insulation.

[0060] In some embodiments, the ink is printed by screen printing 200 ; in other embodiments, the ink may be printed by inkjet printing, curtain coating, electrostatic spray coating, or the like.

[0061] Since the outer metal pattern 112 has been formed in the scrap area 102 in step S2, both the finished product area 101 and the scrap area 102 are provided with metal patterns. During the ink printing process, the flatness of the circuit board body 10 is relatively good, especially the scrap area 102 is usually located at the edge of the circuit board body 10. By providing the outer metal pattern 112 in the scrap area 102, the edge of the circuit board body 10 is not easily warped. Therefore, when printing ink, the overall amount of ink applied to the circuit board body 10 is relatively uniform, so that the ink can evenly cover the outer surface of the circuit board body 10.

[0062] Step S4 : exposing and developing the ink to form a solder resist layer 20 .

[0063] Optionally, the ink is pre-baked to prevent it from sticking to the film during exposure; then, the ink is exposed using high-precision film or LDI (laser direct imaging), and UV light is transmitted through the transparent area to irradiate the ink, causing a photopolymerization reaction and cross-linking and curing the ink; the light-shielded area remains unreacted.

[0064] Then, the ink is developed with a solution to dissolve the unexposed ink and retain the cured area. After development, a solder mask layer 20 is formed. The solder mask layer 20 is provided with a solder mask window, which is used to expose areas such as pads, vias, and gold fingers. Then, a post-curing process can be performed.

[0065] Step S5: removing the waste area 102 to obtain a circuit board.

[0066] Specifically, the circuit board body 10 is milled to obtain an independent circuit board, and the waste area 102 is removed by the milling and will not remain in the finished product area 101, that is, the outer metal pattern 112 added during the production process will not affect the delivered finished circuit board.

[0067] Optionally, outer layer circuits 111 and solder resist layers 20 are provided on both sides of the circuit board body 10 , and the solder resist layer 20 on at least one side can be manufactured according to the above method.

[0068] In the circuit board manufacturing method provided in the embodiment of the present application, in the step of manufacturing the outer layer circuit 111, a plurality of spaced-apart outer layer metal patterns 112 are simultaneously manufactured in the waste area 102, thereby improving the overall flatness of the circuit board and reducing the warping of the circuit board, thereby improving the flatness of the ink in the printing step and solving the problem of uneven ink application caused by board warping. Therefore, the above-mentioned circuit board manufacturing method can improve the uniformity of the ink thickness after the circuit board solder mask processing and improve the processing quality of the circuit board.

[0069] Please refer to Figures 1 to 4 In some embodiments, the finished product area 101 includes at least one finished product unit 1011 and an empty area 1012 to be processed adjacent to the finished product unit 1011; in step S2, when the outer layer circuit 111 is produced on the surface of the circuit board body 10, a plurality of spaced outer metal patterns 112 are simultaneously produced in the empty area 1012 to be processed.

[0070] In some embodiments, the circuit board body 10 is a panel structure, including at least one finished product area 101 and a waste area 102. The finished product area 101 includes at least one finished product unit 1011, and each finished product unit 1011 is used to make a finished circuit board. A waiting area 1012 is provided in the finished product area 101. The waiting area 1012 is the waste area 102 area to be milled. For example, if the shape of the finished circuit board is different from that of the finished product area 101, the waiting area 1012 needs to be removed to obtain the finished circuit board; for example, the finished product includes at least two finished product units 1011, and the portion between adjacent finished product units 1011 is the waiting area 1012.

[0071] In the prior art, the outer layer circuit 111 is located in the finished product area 101, and the outer layer circuit 111 is not set in the waiting area 1012; in the embodiment of the present application, by setting the outer layer metal pattern 112 in the waiting area 1012, the flatness of the substrate can be balanced, the difference between the copper layer and the base material area 1011b can be reduced, and the flatness of the circuit board body 10 can be further improved.

[0072] In some embodiments, the outer metal pattern 112 in the scrap area 102 and the outer metal pattern 112 in the waiting area 1012 have the same shape and size, so that the copper layer is distributed more evenly, which is beneficial to improving the flatness of the circuit board body 10.

[0073] In other embodiments, the outer metal pattern 112 in the scrap area 102 and the outer metal pattern 112 in the waiting area 1012 may be different and designed based on the area of ​​the corresponding region. Optionally, the area of ​​the scrap area 102 is larger than the area of ​​the waiting area 1012, and the size of the outer metal pattern 112 in the scrap area 102 is larger than the size of the outer metal pattern 112 in the waiting area 1012.

[0074] By adopting the above technical solution, when printing ink, the difference between the waste area 102, the finished product area 101 and the waiting area 1012 is small, the flatness of the circuit board body 10 is better, and the overall oil amount of the circuit board body 10 is more uniform, so that the ink can be evenly covered on the outer surface of the circuit board body 10, further improving the uniformity of the ink thickness.

[0075] Figure 4 A finished product area 101 is shown. Figure 5 Schematic diagram of the screen 200 and Figure 4 The corresponding part of the finished product area 101 is shown. Figure 4 and Figure 5 In some embodiments, after the outer layer circuit 111 is produced on the surface of the circuit board body 10, the finished product area 101 is formed with a circuit-dense area 1011a and a substrate area 1011b. The outer layer circuit 111 is located in the circuit-dense area 1011a, and the surface of the substrate area 1011b is not covered with the outer metal layer 11. The length and width of the substrate area 1011b are both greater than or equal to 3 mm.

[0076] The circuit-dense area 1011a refers to the area where multiple circuits in the outer layer circuit 111 are distributed (also called the "copper surface area"), and the substrate area 1011b refers to the area not covered by the outer metal layer 11 (also called the "copper-free area"). One or more substrate areas 1011b can be provided in each finished product area 101.

[0077] Since the outer metal layer 11 on the surface of the substrate area 1011b has been etched away, the height of the substrate area 1011b is lower than that of the circuit-dense area 1011a. After printing ink using the silk screen 200, there will be a difference in the ink height between the substrate area 1011b and the circuit-dense area 1011a, resulting in uneven oil thickness. To this end, the manufacturing method provided in the embodiment of the present application can increase the amount of oil applied to the substrate area 1011b by improving the silk screen 200, improve the uniformity of the oil thickness, and make the ink thickness meet the requirement of ±3um. The embodiment of the present application integrates the silk screens 200 of different mesh sizes corresponding to the empty substrate area 1011b and the circuit-dense area 1011a on the same screen, that is, a screen is woven with silk screens 200 of different mesh sizes corresponding to the area of ​​the substrate to be printed after etching.

[0078] Specifically, step S3 "printing ink on the surface of the circuit board body 10" includes: providing a silk screen 200, the silk screen 200 includes a first silk screen part 210 and a second silk screen part 220, the mesh number of the first silk screen part 210 is greater than the mesh number of the second silk screen part 220; placing the silk screen 200 above the circuit board body 10, so that the first silk screen part 210 is opposite to the circuit dense area 1011a, and the second silk screen part 220 is opposite to the substrate area 1011b, and printing ink on the surface of the circuit board body 10 through the silk screen 200.

[0079] Before printing ink, the substrate area 1011b on the circuit board body 10 is first identified, and then the corresponding screen 200 is made, so that the empty substrate area 1011b and the circuit-dense area 1011a of the screen 200 are set with different mesh counts. The larger the mesh count of the screen 200, the less ink is applied.

[0080] The screen 200 includes a first screen portion 210 and a second screen portion 220. The mesh size of the first screen portion 210 is larger than that of the second screen portion 220. In some embodiments, the required ink thickness is 30 μm. The mesh size of the first screen portion 210 corresponding to the dense circuit area is 56T, while the mesh size of the second screen portion 220 corresponding to the substrate area 1011 b is lower than 56T, such as 48T or 36T. The specific mesh size can be selected based on the required thickness of the finished solder mask ink.

[0081] During the ink printing step, the first screen portion 210 is opposite to the circuit-dense area 1011a, and the second screen portion 220 is opposite to the substrate area 1011b. Since the mesh number of the first screen portion 210 is greater than the mesh number of the second screen portion 220, the amount of ink applied to the substrate area 1011b is larger, so that the substrate area 1011b can be filled with more ink, thereby reducing the ink height difference between the substrate area 1011b and the circuit-dense area 1011a and improving the uniformity of the ink thickness.

[0082] In some embodiments, the viscosity of the ink is 125 dPas to 135 dPas, and the screen printing pressure is in the range of 4.5 kg / cm 2 Up to 5.5kg / cm 2 The distance between the screen 200 and the circuit board body 10 is 6.5 mm to 7.5 mm. Optionally, the angle of the screen printing scraper is 15°±1°.

[0083] By adopting the above technical solution, the stability of silk screen printing can be ensured.

[0084] In some embodiments, during the step of printing ink on the surface of the circuit board body 10, the circuit board body 10 is fixed on the electrostatic base plate of the screen printing machine table, and the electrostatic base plate is used to adsorb the circuit board body 10, so that the positive projection of the circuit board body 10 on the screen printing machine table falls completely within the electrostatic base plate.

[0085] The electrostatic base plate can absorb the circuit board body 10 when printing ink, fix the circuit board body 10 on the screen printing machine table, and avoid uneven oil thickness caused by the difference in oil amount in local positions due to the problem of thin board warping.

[0086] The electrostatic base plate can be made of polytetrafluoroethylene (commonly known as Teflon). The size of the electrostatic base plate is larger than the size of the substrate to be printed, and the flatness of the electrostatic base plate is required to be within ±1um.

[0087] In addition, the screen printing machine also includes an electrostatic generator electrically connected to the screen printing machine table. When printing, the electrostatic generator is turned on to enable the electrostatic base plate fixed to the table to have electrostatic adsorption ability, thereby allowing electrostatic adsorption of the circuit board body 10 to be printed, so that when the ink is printed, the flatness of the circuit board body 10 is high and the amount of oil on the entire board is uniform.

[0088] By adopting the above technical solution, the electrostatic base plate is used to adsorb the circuit board body 10 during the ink printing step, which can further improve the flatness of the circuit board body 10, improve the uniformity of the ink, and further improve the uniformity of the ink thickness.

[0089] Please refer to Figure 3 In some embodiments, the circuit board body 10 includes multiple inner metal layers 12, at least one inner metal layer 12 is provided with an inner metal pattern 122 in the waste area 102, and the inner metal pattern 122 and the outer metal pattern 112 are staggered in their orthographic projections on the outer surface of the circuit board body 10.

[0090] Figure 3 The circuit board body 10 shown has eight circuit layers (L1 to L8), with an insulating layer 13 provided between adjacent circuit layers. The insulating layer 13 may be a prepreg formed by high temperature and high pressure, etc.; a plurality of vias 14 are provided in the circuit board body 10, and the vias 14 are used to conduct electricity between different circuit layers.

[0091] like Figure 3 As shown, in some embodiments, an inner metal pattern 122 is provided in the inner metal layer 12 disposed adjacent to the outer metal layer 11. The inner metal pattern 122 is located in the scrap area 102. It can be understood that the inner metal layer 12 is provided with an inner circuit 121 in the finished product. The orthographic projections of the inner metal pattern 122 and the outer metal pattern 112 on the outer surface of the circuit board body 10 are staggered, and the two can be completely staggered or partially staggered.

[0092] By setting the inner metal pattern 122 in the waste area 102, the flatness of the circuit board body 10 can be further improved. By staggering the inner metal pattern 122 and the outer metal pattern 112, stress can be dispersed and the risk of deformation and warping of the circuit board body can be reduced.

[0093] In some embodiments, the minimum spacing of the outer metal pattern 112 is greater than or equal to the minimum line spacing of the outer circuit 111; and / or the linear size of the outer metal pattern 112 is greater than or equal to the linear size of the smallest pad in the outer circuit 111.

[0094] The minimum pitch of the outer layer circuit 111 is the minimum pitch specified in the design rules for the outer layer circuit 111. By setting the minimum pitch of the outer metal pattern 112 to be greater than or equal to the minimum pitch of the outer layer circuit 111, the minimum pitch of the outer metal pattern can meet the minimum pitch requirement of the outer layer circuit 111, making the production of the outer metal pattern less difficult.

[0095] The linear dimension of the outer metal pattern 112 refers to the linear length of the outer metal pattern 112. By setting the linear dimension of the outer metal pattern 112 to be greater than or equal to the linear dimension of the smallest pad in the outer circuit 111, the outer metal pattern can be made with less difficulty.

[0096] In some embodiments, the outer metal pattern 112 is circular or rectangular; wherein the spacing between any two adjacent outer metal patterns 112 is 0.2 mm to 2 mm; and / or the linear dimension of the outer metal pattern 112 is 1.0 mm to 4.0 mm.

[0097] The spacing between any two adjacent outer metal patterns 112 can be 0.2 mm, 0.5 mm, 1.0 mm, 1.5 mm, 2 mm, etc. By setting the spacing between the outer metal patterns 112 to be greater than or equal to 0.2 mm, the risk of incomplete etching can be avoided; by setting the spacing between the outer metal patterns 112 to be less than or equal to 2 mm, the uniformity of the ink caused by excessive spacing between the outer metal patterns 112 can be avoided.

[0098] The linear dimensions of the outer metal pattern 112 can be 1.0 mm, 1.5 mm, 2.0 mm, 2.5 mm, 3.0 mm, 3.5 mm, 4.0 mm, etc. For example, if the outer metal pattern 112 is circular, the linear dimensions of the outer metal pattern 112 are its diameter; for another example, if the outer metal pattern 112 is square, the linear dimensions of the outer metal pattern 112 are its side lengths. Furthermore, the linear dimensions of the outer metal pattern 112 can be between 1.0 mm and 2.0 mm.

[0099] By setting the linear dimension of the outer metal pattern 112 to be greater than or equal to 1.0 mm, incomplete etching is avoided and the manufacturing difficulty is reduced. By setting the linear dimension of the outer metal pattern 112 to be less than or equal to 4.0 mm, the outer metal pattern 112 is evenly distributed, taking into account both coverage efficiency and etching uniformity.

[0100] In some embodiments, the plurality of outer metal patterns 112 are evenly distributed within the scrap area 102 .

[0101] There are various ways to distribute the multiple outer metal patterns 112. In some embodiments, the multiple outer metal patterns 112 are evenly distributed in a rectangular grid array. The outer metal patterns 112 can be square or circular. This allows for a high degree of edge alignment of the multiple outer metal patterns 112, which helps improve the flatness of the circuit board body 10.

[0102] In some embodiments, the plurality of outer metal patterns 112 are evenly distributed in a staggered array. The outer metal patterns 112 may be circular and arranged in a hexagonal honeycomb structure, with each row offset by half a pitch.

[0103] In some embodiments, the multiple outer metal patterns 112 may be arranged in a zoned, gradient pattern. The scrap zone 102 includes a central portion and an edge portion located outside the central portion. A portion of the outer metal patterns 112 is evenly distributed in a rectangular grid array or a staggered array in the central portion, while another portion of the outer metal patterns 112 is arranged sequentially with gradually increasing spacing at the edge portion. This distribution method balances the coverage of the outer metal patterns 112 with the shape of the scrap zone 102, and is suitable for scrap zones 102 with irregular shapes or structures to be avoided (such as positioning holes).

[0104] In addition, the plurality of outer metal patterns 112 in the waiting empty area 1012 may also be evenly distributed, and the distribution method may be set according to the area and / or shape of the waiting empty area 1012 .

[0105] By evenly distributing the plurality of outer metal patterns 112 in the waste area 102 , the overall flatness of the circuit board is improved.

[0106] In the circuit board manufacturing method provided in the embodiment of the present application, in the data for manufacturing the outer layer circuit 111, the waste area 102 and the empty area 1012 to be processed in the finished product area 101 are added to arrange the outer metal pattern 112, balance the flatness of the substrate, reduce the difference between the copper and substrate area 1011b, improve the flatness of the circuit board body 10, and complete the outer metal pattern 112 and the outer layer circuit 111 together. Other previous processes up to the solder mask pre-treatment can be processed according to the normal process flow. During the screen printing process, an electrostatic bottom plate is used to adsorb the circuit board body 10 to ensure the flatness and fixation of the circuit board body 10. In addition, with reference to the outer layer graphic design, meshes of different mesh sizes are used in the substrate area 1011b and the circuit-dense area 1011a to produce a composite screen to adjust the amount of ink applied and reduce the difference in ink thickness caused by the height difference between the substrate area 1011b and the circuit-dense area 1011a, so that the printed ink is highly consistent.

[0107] The above-mentioned circuit board manufacturing method can reduce the influence of factors such as board warping, improve the flatness of the circuit board body 10 during the ink printing process, improve the uniformity of the ink thickness, and can achieve the uniformity requirement of ink thickness difference of ±3um, thereby improving the quality of the circuit board.

[0108] An embodiment of the second aspect of the present application provides a circuit board, which is manufactured using the circuit board manufacturing method provided in the first aspect.

[0109] The circuit board provided in the embodiment of the present application improves the uniformity of ink thickness. The circuit board may be, but is not limited to, a carrier board, an HDI board, etc.

[0110] 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 various embodiments of the present application, and should all be included in the scope of protection of the present application.

Claims

1. A method for manufacturing a circuit board, characterized in that: include: Providing a circuit board body on which an outer layer circuit is to be manufactured, wherein the circuit board body comprises at least one finished product area and a waste material area provided outside the finished product area; Fabricating an outer layer circuit on the surface of the circuit board body, and simultaneously fabricating a plurality of outer layer metal patterns distributed at intervals in the waste area; printing ink on the surface of the circuit board body; exposing and developing the ink to form a solder resist layer; The waste area is removed to obtain a circuit board.

2. The method for manufacturing a circuit board according to claim 1, wherein: The finished product area includes at least one finished product unit and an empty waiting area adjacent to the finished product unit; When the outer layer circuit is produced on the surface of the circuit board body, a plurality of the outer layer metal patterns distributed at intervals are produced in the blank area to be processed.

3. The method for manufacturing a circuit board according to claim 1, wherein: After the outer layer circuit is formed on the surface of the circuit board body, the finished product area is formed with a circuit-intensive area and a substrate area, the outer layer circuit is located in the circuit-intensive area, the surface of the substrate area is not covered with the outer metal layer, and the length and width of the substrate area are both greater than or equal to 3 mm; Printing ink on the surface of the circuit board body includes: Providing a wire mesh, the wire mesh comprising a first wire mesh portion and a second wire mesh portion, wherein the mesh number of the first wire mesh portion is greater than the mesh number of the second wire mesh portion; The screen is placed above the circuit board body so that the first screen portion faces the circuit-dense area and the second screen portion faces the substrate area, and ink is printed on the surface of the circuit board body through the screen.

4. The method for manufacturing a circuit board according to claim 3, wherein: The viscosity of the ink is 125dPas to 135dPas, and the screen printing pressure ranges from 4.5kg / cm 2 Up to 5.5kg / cm 2 The distance between the silk screen and the circuit board body is 6.5 mm to 7.5 mm.

5. The method for manufacturing a circuit board according to claim 1, wherein: In the step of printing ink on the surface of the circuit board body, the circuit board body is fixed on the electrostatic base plate of the screen printing machine table, and the electrostatic base plate is used to adsorb the circuit board body, so that the orthographic projection of the circuit board body on the screen printing machine table completely falls within the electrostatic base plate.

6. The method for manufacturing a circuit board according to claim 1, wherein: The circuit board body includes multiple inner metal layers, at least one of which is provided with an inner metal pattern in the waste area, and the inner metal pattern and the outer metal pattern are staggered in their orthographic projections on the outer surface of the circuit board body.

7. The method for manufacturing a circuit board according to any one of claims 1 to 6, wherein: The spacing of the outer metal patterns is greater than or equal to the minimum line spacing of the outer circuits; and / or, The linear size of the outer metal pattern is greater than or equal to the linear size of the smallest pad in the outer circuit.

8. The method for manufacturing a circuit board according to any one of claims 1 to 6, wherein: The outer metal pattern is circular or rectangular; Wherein, the distance between any two adjacent outer metal patterns is 0.2 mm to 2 mm; and / or, The linear dimension of the outer metal pattern is 1.0 mm to 4.0 mm.

9. The method for manufacturing a circuit board according to any one of claims 1 to 6, wherein: A plurality of outer metal patterns are evenly distributed in the scrap area.

10. A circuit board, characterized in that: The circuit board is manufactured using the circuit board manufacturing method according to any one of claims 1 to 9.

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