Circuit board manufacturing method and circuit board

Abstract

The invention relates to the technical field of circuit board manufacturing, and provides a circuit board manufacturing method and a circuit board, and the method comprises the steps: electroplating a golden finger on a production board through an electroplating lead; covering selective printing ink on the part of the electroplated lead and the golden finger; forming at least one finished board on the production board along the routing forming line; carrying out bevel edge processing on the finished board; covering an OSP film on the finished board; and removing the selective ink. According to the circuit board manufacturing method, after the golden finger is electroplated, the part of the electroplated lead and the golden finger are covered with the selective ink, and the selective ink is removed after the OSP process, so that the ratio of the area of the exposed gold layer to the area of the nickel layer and the copper layer at the bevel edge in the OSP process is small, that is, the galvanic effect is not obvious, and the nickel layer and the copper layer are slightly corroded; and the risk that the nickel-gold layer tilts and falls off is reduced, so that the risk of short circuit is reduced.

Description

Technical Field

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

[0002] In the process of electroplating gold fingers, it is usually necessary to design electroplating leads so that the gold fingers can be electroplated by energizing the electroplating leads. After the electroplating of gold fingers is completed, the electroplating leads are not allowed to remain in the finished circuit board and need to be removed.

[0003] For storage products, after the electroplating of gold fingers and gong plates, beveling is usually used to remove the residual electroplated leads. In the OSP (Organic Solderability Preservative) process, the nickel and copper layers at the bevel are prone to the Giovanni effect with the gold layer of the gold fingers, resulting in the replacement of the more active metal nickel and copper, which is manifested as the nickel and copper layers being corroded. After the corrosion, the unstable nickel-gold layer will cause problems such as warping and falling off. The fallen nickel-gold layer may enter the welding surface, causing the risk of short circuit. Summary of the invention

[0004] In view of this, the embodiments of the present application provide a circuit board manufacturing method and a circuit board to solve the problem of the nickel-gold layer warping and falling off.

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

[0006] Electroplating gold fingers on production boards using electroplated leads;

[0007] Covering the electroplated lead portion and the gold finger with selected ink;

[0008] Forming the production board into at least one finished board along a gong board forming line;

[0009] Performing beveling processing on the finished board to remove the electroplated leads remaining on the finished board;

[0010] Covering the finished board with an OSP film;

[0011] The selected ink is removed.

[0012] The beneficial effects of the circuit board manufacturing method provided by the embodiment of the present application are as follows: after electroplating the gold finger, the electroplated lead part and the gold finger are covered with selective ink, and the selective ink recedes after the OSP process, so that the ratio of the exposed gold layer area to the nickel layer and copper layer area at the bevel in the OSP process is small, that is, the Giovanni effect is not obvious, and the nickel layer and copper layer are slightly corroded, thereby reducing or even avoiding the risk of warping and falling off of the nickel-gold layer.

[0013] In some embodiments, a first window is left at a position of the selected ink corresponding to the gold finger, and after the finished board is beveled, the gold finger is electrically tested through the first window.

[0014] The beneficial effects of the above technical solution are: the gold finger is electrically tested through the first window to ensure the reliability of each product and improve product quality. In addition, the needle point is designed at the first window of the selected ink, and the rest of the positions are protected by the selected ink, which can improve the problem of gold finger scratches.

[0015] In some embodiments, the first window is circular, and the diameter of the first window is 600-800um.

[0016] The beneficial effects of adopting the above technical solution are as follows: the cross-section of the electrical measuring probe is usually circular, and the first window is designed to be circular. While ensuring that the electrical measuring probe is in full contact with the gold finger, the area of ​​the first window can be reduced as much as possible, that is, the area of ​​the exposed gold layer is reduced, and the ratio of the exposed gold layer area to the nickel layer and copper layer area at the bevel is further reduced.

[0017] In some embodiments, before electroplating the gold finger, the electroplating lead is widened.

[0018] The beneficial effect of adopting the above technical solution is that after the electroplated lead is widened, the area of ​​the nickel layer and the copper layer at the bevel can be increased, and the ratio of the exposed gold layer area to the nickel layer and the copper layer area at the bevel can be further reduced.

[0019] In some embodiments, before the gong plate is formed, the electroplating lead is covered with solder resist ink; the solder resist ink does not cover the gong plate forming line, the selected chemical ink covers the gong plate forming line, and the solder resist ink and the selected chemical ink are spaced apart.

[0020] The beneficial effects of adopting the above technical solution are as follows: when the gong plate is formed, the moving direction of the forming knife is perpendicular to the arrangement direction of the electroplated leads, and the forming knife will exert an external force on the electroplated leads. When the electroplated leads are covered with solder mask ink, the adhesion of the electroplated leads can be enhanced, and the pulling force of cutting the electroplated leads during gong plate forming can be reduced; the selected ink can reduce the external stress of the nickel-gold layer caused by the bevel processing and reduce nickel brittleness.

[0021] In some embodiments, the distance between the edge of the solder mask ink and the gong plate forming line is 600-800um, the distance between the edge of the selected ink and the gong plate forming line is 500-700um, and the distance between the edge of the selected ink and the side of the gold finger is 300-500um.

[0022] The beneficial effects of adopting the above technical solution are as follows: the distance between the edge of the solder resist ink and the gong plate forming line is 600-800um, so as to avoid the gong plate forming line in the solder resist area, causing the end of the gold finger close to the electroplated lead to be covered with solder resist ink; the distance between the edge of the selected ink and the gong plate forming line is 500-700um, so as to ensure that under the premise of the gong plate forming deviation, the electroplated leads are covered with the selected ink during the bevel processing; the distance between the edge of the selected ink and the side of the gold finger is 300-500um, even if the selected ink is deviated, it can ensure that the gold finger is still protected by the selected ink, thereby improving the problem of gold finger scratches.

[0023] In some embodiments, the current density of electroplating the gold finger is 0.6-0.8 ASD, and / or the brightener concentration is 0.1%-0.3%.

[0024] The beneficial effects of adopting the above technical solution are as follows: by optimizing the current density, an electroplated gold product with small pores and small grains can be obtained, which can reduce the internal stress of the nickel layer and thus improve the nickel brittleness problem of the nickel-gold layer.

[0025] In some embodiments, the processing speed of the beveling process is 2-3 m / min, and / or the processing length of the beveling knife of the beveling process is 6-8 m.

[0026] The beneficial effects of adopting the above technical solution are: by reducing the processing speed, the wear rate of the beveling knife can be reduced; by shortening the processing length, the beveling knife can be replaced in time before it becomes blunt. Based on the above two factors, ensuring that the beveling knife is sharp enough is conducive to ensuring the cutting quality of the beveling knife during beveling processing.

[0027] In some embodiments, an organic stripping liquid is used to strip the selected ink.

[0028] The beneficial effects of adopting the above technical solution are as follows: the organic film stripping liquid has relatively weaker reactivity than the sodium hydroxide film stripping liquid, which can prevent the film stripping liquid from damaging the OSP film surface.

[0029] The second aspect of the present application provides a circuit board, which is manufactured using the circuit board manufacturing method described in the first aspect.

[0030] The circuit board adopts any one or more embodiments of the circuit board manufacturing method described above, and thus has the beneficial effects of the above embodiments, which will not be described one by one here.

[0031] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] 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 conventional technical descriptions 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 work.

[0033] Figure 1 It is a partial schematic diagram of a gold finger in the prior art;

[0034] Figure 2 yes Figure 1 AA cross-sectional view with cured sheet;

[0035] Figure 3 is a flow chart of a circuit board manufacturing method provided by some embodiments of the present application;

[0036] Figure 4 It is a schematic diagram of a structure in which solder resist ink is covered on electroplated leads provided in some embodiments of the present application;

[0037] Figure 5 is Figure 4 A schematic diagram of the structure of the selected ink is covered on the basis;

[0038] Figure 6 yes Figure 5 Schematic diagram of the structure after the gong plate forming and beveling process;

[0039] Figure 7 yes Figure 6 Cross-sectional view along the BB axis with cured sheet.

[0040] The meanings of the marks in the figure are:

[0041] 10. Gold finger; 11. Gold layer; 12. Nickel layer; 13. Copper layer;

[0042] 20. Select ink; 21. First window opening;

[0043] 30. Gold finger lead wire; 31. External lead wire; 32. Electroplated lead wire;

[0044] 40. Solder resist ink;

[0045] 50. Gong plate forming line;

[0046] 60. Cured sheet;

[0047] 70, bevel edge; 71, copper-nickel cross section;

[0048] 80. Bite area;

[0049] 90. Hanging nickel gold. DETAILED DESCRIPTION

[0050] The following embodiments of the technical solution of the present application are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0051] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0052] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0053] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0054] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0055] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0056] In the description of the embodiments of the present application, the orientations or positional relationships indicated by technical terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "vertical", "horizontal", "top", "bottom", "inside" and "outside" are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they should not be understood as limitations on the embodiments of the present application.

[0057] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0058] The partial design diagram of the product is as follows Figure 1 and Figure 2 As shown, this product is a storage product, and the electroplated lead 32 is designed at the end of the gold finger 10. Most of the electroplated lead 32 is removed by gong plate forming and bevel processing, and a small amount of electroplated lead 32 remains at the end of the gold finger 10.

[0059] Customers generally only allow copper to be exposed after beveling, but do not allow the nickel-gold layer to lift or fall off after beveling, as the falling debris may cause reliability risks.

[0060] The main reasons for the warping and falling off of the nickel-gold layer are: when the nickel-gold layer is relatively brittle (nickel brittle), when the nickel-gold layer at the bevel 70 is subjected to the external force of the bevel processing, it will cause cracks in the nickel-gold layer after the bevel processing. During the OSP pre-treatment process and the OSP film coating process, the nickel layer 12 and the copper layer 13 at the bevel 70 are prone to the Giovanni effect with the gold layer of the gold finger 10, resulting in the replacement of the more active metal nickel and copper, which is manifested as the nickel layer 12 and the copper layer 13 being corroded to form a corroded area 80, and the nickel-gold layer at the corroded area 80 forms a suspended nickel-gold 90, which will have problems of warping and falling off.

[0061] like Figure 1 As shown, assuming that the length L1 of the copper-nickel cross section 71 at the hypotenuse 70 is 40um and the width W1 is 100um, the area S1 of the copper-nickel cross section 71 is 4000um 2 The length of the gold finger 10 is 2000um and the width is 800um. Without the electroplated lead 32, the area S3 is 1600000um. 2, then the ratio of gold to nickel and copper is 400:1. According to common knowledge, when the ratio of gold to nickel and copper is greater than 200:1, the Giovanni effect is significant, and when the ratio of gold to nickel and copper is 400:1, the Giovanni effect is even more serious.

[0062] In order to solve the above problems, the embodiment of the first aspect of the present application proposes a circuit board manufacturing method suitable for storage products. Figure 3 , Figure 5 and Figure 7 , the circuit board manufacturing method includes:

[0063] S100 , electroplating the gold finger 10 on the production board using the electroplating lead 32 .

[0064] The production board has a board edge process area and a finished product area, and the finished product area can form at least one finished board; wherein, a plurality of gold fingers 10 are arranged side by side on each finished board.

[0065] The process of electroplating the gold finger 10 is as follows: first, a nickel layer 12 is plated on the copper layer 13 of the production board, and then a gold layer 11 is plated on the nickel layer 12; that is, the gold finger 10 is composed of the copper layer 13, the nickel layer 12, and the gold layer 11, and the gold finger 10 is on the curing sheet 60. Among them, nickel and gold can improve the wear resistance and conductivity of the gold finger 10.

[0066] It should be noted that the gold finger lead 30 includes an outer lead 31 and multiple electroplated leads 32, the first ends of the multiple electroplated leads 32 are all connected to the outer lead 31, and the second ends of the multiple electroplated leads 32 are respectively connected to multiple gold fingers 10; wherein the outer lead 31 is used for an external power supply.

[0067] S200 , covering the plated lead 32 and the gold finger 10 with the selected ink 20 .

[0068] The selected ink 20 protects the gold layer 11 . The selected ink 20 completely covers the gold finger 10 , and the selected ink 20 covers a portion of the electroplating lead 32 close to the gold finger 10 .

[0069] S300, forming the production plate along the gong plate forming line 50 into at least one finished plate.

[0070] It will be appreciated that a production panel may be gong formed into one, two or more than three finished panels.

[0071] During the gong plate forming process, cutting is performed at the position of the gong plate forming line 50, that is, most of the outer lead 31 and the electroplated lead 32 are removed.

[0072] S400, beveling the finished board to remove the residual electroplated leads 32 on the finished board.

[0073] Beveling machine is used to complete the bevel 70 of the gold finger 10 according to the design angle and depth requirements, such as Figure 6 The inclined angle of the hypotenuse 70 is generally 30°-45°.

[0074] It should be noted that, in order to prevent the bevel cutter from cutting the gold finger 10 , the bevel cutter starts cutting on the electroplating lead 32 , that is, a small amount of the electroplating lead 32 will still not be removed.

[0075] S500, Cover the finished board with OSP film.

[0076] OSP film, or organic solder protection film, is a layer of organic film grown on the clean bare copper surface by chemical methods. This film is used to protect the copper surface from rusting (oxidation or sulfide, etc.) in the natural environment; at the same time, in the subsequent high temperature of welding, this protective film is easily removed by the flux quickly, so that the exposed clean copper surface can be combined with the molten solder in a very short time to form a solid solder joint. It can be seen from the formation principle of OSP film that it will not cover the selected ink 20, that is, it will not affect the removal of the selected ink 20.

[0077] S600, removing the selected ink 20.

[0078] The selected ink 20 is removed by using a stripping liquid. It is understood that the stripping liquid can be an organic stripping liquid or an inorganic stripping liquid.

[0079] The beneficial effects of the circuit board manufacturing method provided by the embodiment of the present application are as follows: after the gold finger 10 is electroplated, the portion of the electroplated lead 32 and the gold finger 10 are covered with the selective ink 20, and the selective ink 20 is removed after the OSP process, so that the ratio of the area of ​​the exposed gold layer 11 in the OSP process to the area of ​​the nickel layer 12 and the copper layer 13 at the bevel 70 is smaller, that is, the Galvani effect is not obvious, the nickel layer 12 and the copper layer 13 are slightly corroded, the corroded area 80 is not obvious, and the nickel-gold layer hardly forms hanging nickel-gold 90, thereby reducing or even avoiding the risk of warping and falling off.

[0080] It should be noted that after the nickel layer 12 and the copper layer 13 are corroded, a portion of nickel remains on the gold layer 11 to form a nickel-gold layer.

[0081] Please also refer to Figures 1 to 3 In some embodiments, a first window 21 is left at the position of the selected ink 20 corresponding to the gold finger 10 , and the gold finger 10 is electrically tested through the first window 21 .

[0082] The first window 21 exposes part of the gold finger 10 so as to contact the probe during electrical testing; the shape of the first window 21 is not limited in this application, for example, the shape of the first window 21 can be circular, elliptical, polygonal, or irregular, etc. Optionally, two first windows 21 are provided.

[0083] During electrical testing, a needle is inserted from the first window 21 to contact the exposed portion of the gold finger 10 , thereby testing the conductive performance of the gold finger 10 .

[0084] The gold finger 10 is electrically tested through the first window 21 to ensure the reliability of each product and improve product quality. In addition, the needle point is designed at the first window 21 of the selected ink 20, and the rest of the positions are protected by the selected ink 20, which can improve the problem of gold finger 10 scratching.

[0085] In some embodiments, the first window 21 is circular, and a diameter D1 of the first window 21 is 600-800 um.

[0086] Optionally, the diameter D1 of the first window 21 may be 600um, 650um, 700um, 750um or 800um, etc.

[0087] Optionally, the center point of the first window 21 is located at or close to the middle position in the width direction of the gold finger 10 .

[0088] Based on the above technical solution, the cross-section of the electrical measuring probe is usually circular, and the first window 21 is designed to be circular. While ensuring that the electrical measuring probe is in full contact with the gold finger 10, the area of ​​the first window 21 can be reduced as much as possible, that is, the area of ​​the exposed gold layer 11 can be reduced, and the ratio of the area of ​​the exposed gold layer 11 to the area of ​​the nickel layer 12 and the copper layer 13 at the hypotenuse 70 can be further reduced.

[0089] In other embodiments, the first window 21 may be a polygon, for example, the first window 21 is a square. In this case, the side length of the first window 21 may be 600um, 650um, 700um, 750um or 800um.

[0090] In some embodiments, before electroplating the gold finger 10 , the electroplating lead 32 is widened.

[0091] For example, before the electroplating lead 32 is widened, please refer to Figure 1 , the width W1 of the copper-nickel cross section 71 is 100um, the length L1 is 40um, and the area S1 of the copper-nickel cross section 71 is 4000um 2 The diameter D1 of the first window 21 is 600um, and the exposed gold layer area S4 of the gold finger 10 is 282600um 2 , that is, the ratio of gold to nickel and copper is about 70:1.

[0092] After the plating lead 32 is widened, please refer to Figure 6 For example, the width W2 of the copper-nickel cross section 71 is 150um, and the length L2 is 40um, then the area S2 of the copper-nickel cross section 71 is 6000um. 2 The diameter D1 of the first window 21 is 600um, and the exposed gold layer area S4 of the gold finger 10 is 282600um 2 , that is, the ratio of gold to nickel and copper is about 47:1.

[0093] Based on the above technical solution, after the electroplated lead 32 is widened, the area of ​​the nickel layer 12 and the copper layer 13 at the bevel 70 can be increased, and the ratio of the area of ​​the exposed gold layer 11 to the area of ​​the nickel layer 12 and the copper layer 13 at the bevel 70 can be further reduced, thereby further weakening the Giovanni effect and reducing the corrosion of the nickel layer 12 and the copper layer 13.

[0094] Please also refer to Figure 4 and Figure 5 In some embodiments, before the gong plate is formed, the solder resist ink 40 is covered on the electroplating lead 32; the solder resist ink 40 does not cover the gong plate forming line 50, the selected ink 20 covers the gong plate forming line 50, and the solder resist ink 40 and the selected ink 20 are arranged at intervals.

[0095] It can be understood that the solder resist ink 40 may cover the external leads 31 or may not cover the external leads 31 .

[0096] The solder resist ink 40 and the selective ink 20 are covered in no particular order. It can be understood that the solder resist ink 40 can be covered before or after the selective ink 20, or the solder resist ink 40 and the selective ink 20 can be covered at the same time.

[0097] When the gong plate is formed, the moving direction of the forming knife is perpendicular to the arrangement direction of the electroplated lead 32, and the forming knife will apply an external force to the electroplated lead 32. When the electroplated lead 32 is covered with solder mask ink 40, the adhesion of the electroplated lead 32 can be enhanced, reducing the pulling force of cutting the electroplated lead 32 during the gong plate forming.

[0098] The selected ink 20 can reduce the external stress of the nickel-gold layer caused by the bevel processing and reduce the brittleness of nickel.

[0099] In some embodiments, the distance L5 between the edge of the solder resist ink 40 and the gong plate forming line 50 is 600-800 um, and the distance L3 between the edge of the selective ink 20 and the gong plate forming line 50 is 500-700 um.

[0100] It can be understood that the distance L5 between the edge of the solder mask ink 40 and the gong plate forming line 50 can be 600um, 650um, 700um, 750um or 800um, etc.; the distance L3 between the edge of the selected ink 20 and the gong plate forming line 50 can be 500um, 550um, 600um, 650um or 700um, etc. However, it is necessary to ensure that the solder mask ink 40 and the selected ink 20 are spaced apart, that is, the solder mask ink 40 and the selected ink 20 are neither in contact with nor overlapped.

[0101] The distance between the edge of the solder resist ink 40 and the gong plate forming line 50 is 600-800um. The solder resist ink 40 covers the electroplated lead 32 as much as possible in order to reduce the pulling force of the gong plate forming on the electroplated lead 32. The three major elements of force are size, direction and action point. Here, the solder resist ink 40 is moved to the gong plate forming line 50 as much as possible, which is equivalent to adjusting the action point. The edge of the solder resist ink can be regarded as a door axis. The gong plate forming is equivalent to pushing the door axis. The closer the edge of the solder resist ink is to the gong plate forming line 50, the harder it is to push the door, and the smaller the impact on the electroplated lead 32 during the gong plate forming, the smaller the impact on nickel embrittlement. The solder resist ink 40 cannot be too close to the gong plate forming line 50 to avoid the gong plate forming line 50 being in the solder resist area, causing the end of the gold finger 10 close to the electroplated lead 32 to be covered with the solder resist ink 40. The distance between the edge of the selected ink 20 and the gong plate forming line 50 is 500-700um, so as to ensure that the electroplating leads 32 are covered with the selected ink 20 during the bevel processing under the premise of the gong plate forming deviation.

[0102] Please refer to Figure 5 In some embodiments, the distance L4 between the edge of the selected ink 20 and the side of the gold finger 10 is 300-500 um. The side of the gold finger 10 refers to one side in the arrangement direction of the plurality of gold fingers 10 .

[0103] It can be understood that the distance L4 between the edge of the selected ink 20 and the side of the gold finger 10 can be 300um, 350um, 400um, 450um or 500um, etc.

[0104] Based on the above solution, even if the selected ink 20 is offset, it can ensure that the gold finger 10 is still protected by the selected ink 20, thereby improving the scratch problem of the gold finger 10.

[0105] In some embodiments, the current density of the electroplated gold finger 10 is 0.6-0.8 ASD, and the brightener concentration is 0.1%-0.3%.

[0106] It can be understood that the current density of the electroplated gold finger 10 can be 0.6ASD, 0.7ASD or 0.8ASD, etc. The current density is a physical quantity that describes the strength and flow direction of the current at a certain point in the circuit. In the field of electroplating, the unit of current density is ampere / square decimeter, recorded as ASD.

[0107] It is understood that the concentration of the brightener may be 0.1%, 0.2% or 0.3%, etc. The brightener is a chemical additive used to improve the glossiness of the coating.

[0108] By optimizing the current density, an electroplated gold product with small pores and small grains can be obtained, which can reduce the internal stress of the nickel layer 12 and further improve the nickel brittleness problem of the nickel-gold layer.

[0109] In some embodiments, the processing speed of the beveling process is 2-3 m / min, and the processing length of the beveling knife of the beveling process is 6-8 m.

[0110] It can be understood that the processing speed of the beveling process can be 2m / min or 3m / min, etc. The processing length of the beveling knife for the beveling process can be 6m, 7m or 8m, etc.

[0111] By reducing the processing speed, the wear rate of the beveling knife can be reduced; by shortening the processing length, the beveling knife can be replaced in time before it becomes blunt. Based on the above two factors, ensuring that the beveling knife is sharp enough is conducive to ensuring the cutting quality of the beveling knife during beveling processing.

[0112] In some embodiments, an organic stripping liquid is used to strip the selected ink 20 .

[0113] Optionally, the organic film stripping liquid can be a 25% tetramethylammonium hydroxide film stripping liquid. Of course, other organic film stripping liquids can also be used.

[0114] Compared with sodium hydroxide stripping solution, organic stripping solution has relatively weaker reactivity, which can prevent the stripping solution from damaging the OSP membrane surface.

[0115] The specific steps of the circuit board manufacturing method provided in some embodiments of the present application are as follows:

[0116] Pre-process: Complete the pre-process (cutting, inner layer circuit, AOI, lamination, drilling target, milling edge, drilling, filling hole) according to the normal process.

[0117] Outer layer circuit: Optimize the width of the electroplated lead 32 of the outer layer circuit. Usually, the electroplated lead 32 designed by the customer is a curved lead. Therefore, there are differences in the position after the gong plate is formed and the bevel processing. The position is widened so as not to be bevel to the gold finger 10, so as to increase the area of ​​the nickel layer 12 and the copper layer 13 after the bevel processing.

[0118] Solder mask: After pre-treatment → printing → pre-baking → exposure → development, a layer of solder mask ink 40 is covered on the product with the outer layer circuit to reduce the external force generated by the gong plate forming on the electroplated lead 32. However, the solder mask ink cannot be too close to the gong plate forming line 50 to avoid the gong plate forming in the solder mask area, which causes the end of the gold finger 10 close to the electroplated lead 32 to be covered with solder mask ink 40. The distance L5 from the gong plate forming line 50 to the edge of the solder mask ink 40 can be designed to be 600-800um. Optionally, the distance L5 is 700um.

[0119] Circuit before gold plating: Anti-gold plating dry film is set before gold plating, and the anti-gold plating dry film has a second window at the position of the gold finger 10. In order to avoid the position of the electroplated lead 32 not being electroplated due to the deviation of the bevel equipment, the anti-gold plating dry film has a third window at the position of part of the electroplated lead 32, wherein the second window is connected to the third window. The length of the third window is 0.2-0.3mm, preferably 0.25mm, and a position for the electroplating clamp is reserved.

[0120] Electroplating gold finger 10: The current density is designed to be in the range of 0.6-0.8ASD, optionally 0.8ASD, and the brightener concentration is controlled to be 0.1%-0.3%, optionally 0.2%. By optimizing the current density, an electroplated gold product with small pores and small grains can be obtained, which can reduce the internal stress of the nickel layer 12 and thus improve the nickel brittleness problem of the nickel-gold layer.

[0121] Remove the anti-gold plating dry film: Use organic film stripping liquid to remove the anti-gold plating dry film.

[0122] Covering selected ink 20: The distance L3 from the edge of the selected ink 20 to the gong plate forming line 50 is 500-700um, and optionally, the distance L3 is 600um. In the case of the gong plate forming deviation, it is ensured that the electroplated leads 32 are covered by the selected ink 20 during the bevel processing; the distance L4 from the side of the gold finger 10 to the selected ink 20 is 300-500um, and optionally, the distance L4 is 300um. In the case of the selected ink 20 deviation, it is ensured that the gold finger 10 is still protected by the selected ink 20, and the problem of gold finger 10 scratching is improved. In addition, the selected ink 20 can reduce the external stress of the bevel processing on the nickel-gold layer and reduce nickel brittleness. The selected ink 20 reserves a first window 21 with a diameter D1 of 600-800um. Optionally, the diameter D1 is 600um. The first window 21 is used for electrical measurement of the lower needle.

[0123] Gong plate forming: Use a gong machine to cut the production plate into one or more finished plates using corresponding materials.

[0124] Beveling processing: The finished board passes through the beveling machine to complete the beveling 70 according to the customer's angle and depth requirements. The beveling processing speed is required to be adjusted from the conventional 4m / min to 2-3m / min. Optionally, the beveling knife's travel speed is 2m / min, and the processing length of the beveling knife is adjusted from the conventional 10m to 6-8m. Optionally, the processing length of the beveling knife is 8m.

[0125] Electrical measurement: The needle point is designed to be located at the position of the first window 21 of the selected ink 20, and the remaining positions are protected by the selected ink 20, which can improve the problem of gold finger 10 being scratched.

[0126] OSP: The product with the selected ink 20 (with the first window 21 at the gold finger position) is passed through the OSP line, and the uncovered pads are covered with a layer of OSP film. Since the ratio of gold to nickel and copper is 47:1 at this time, the Giovanni effect is small. Therefore, the nickel layer 12 and the copper layer 13 react slightly, which will not cause the nickel-gold layer to fall off and cause the abnormality of the electroplated lead 32 to lift.

[0127] Stripping ink 20: Stripping ink 20 uses an organic stripping liquid, which can use a 25% concentration of tetramethylammonium hydroxide stripping liquid; the organic stripping liquid has a relatively weaker reactivity than the sodium hydroxide stripping liquid, which can prevent the stripping liquid from damaging the OSP film surface.

[0128] Complete the post-processes (FQC, FQA, packaging) in sequence.

[0129] A second aspect of the present application provides a circuit board, which is manufactured using the circuit board manufacturing method described in the first aspect.

[0130] The circuit board adopts any one or more embodiments of the circuit board manufacturing method described above, and thus has the beneficial effects of the above embodiments, which will not be described one by one here.

[0131] 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 circuit board, characterized in that: include: Electroplating gold fingers on production boards using electroplated leads; Covering the electroplated lead portion and the gold finger with selected ink; Forming the production board into at least one finished board along a gong board forming line; Performing beveling processing on the finished board to remove the electroplated leads remaining on the finished board; Covering the finished board with an OSP film; The selected ink is removed.

2. The method for manufacturing a circuit board according to claim 1, wherein: A first window is reserved at the position of the selected ink corresponding to the gold finger, and after the finished board is beveled, the gold finger is electrically tested through the first window.

3. The method for manufacturing a circuit board according to claim 2, wherein: The first opening is circular, and the diameter of the first opening is 600-800um.

4. The method for manufacturing a circuit board according to claim 1, wherein: Before electroplating the gold finger, the electroplating lead is widened.

5. The method for manufacturing a circuit board according to claim 1, wherein: Before the gong plate is formed, the electroplating lead is covered with solder resist ink; the solder resist ink does not cover the gong plate forming line, the selected chemical ink covers the gong plate forming line, and the solder resist ink and the selected chemical ink are arranged at intervals.

6. The method for manufacturing a circuit board according to claim 5, characterized in that: The distance between the edge of the solder resist ink and the gong plate forming line is 600-800um, the distance between the edge of the selected ink and the gong plate forming line is 500-700um, and the distance between the edge of the selected ink and the side of the gold finger is 300-500um.

7. The method for manufacturing a circuit board according to any one of claims 1 to 6, characterized in that: The current density of electroplating the gold finger is 0.6-0.8ASD, and / or the brightener concentration is 0.1%-0.3%.

8. The method for manufacturing a circuit board according to any one of claims 1 to 6, characterized in that: The processing speed of the beveling process is 2-3 m / min, and / or the processing length of the beveling cutter of the beveling process is 6-8 m.

9. The method for manufacturing a circuit board according to any one of claims 1 to 6, characterized in that: When removing the selected ink, an organic film stripping liquid is used.

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

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