Circuit board manufacturing method and circuit board

Abstract

The invention relates to the technical field of circuit board manufacturing, in particular to a circuit board manufacturing method and a circuit board, and the circuit board manufacturing method comprises the steps that a substrate is provided, the substrate is provided with a circuit layer and is provided with a golden finger, an electroplating lead and an OSP bonding pad, the golden finger is covered with a nickel-gold layer, the golden finger comprises a first finger, the electroplating lead comprises a first lead, and the first finger is provided with a second finger; the first finger and the first lead are connected and electrically conducted; an etching protection film is attached to the circuit layer, the etching protection film comprises a first protection part, the first protection part comprises a first part and a second part, the first part covers the nickel-gold layer on the first finger, and the middle of the end, away from the first part, of the second part is arranged in a sunken mode in the direction close to the first part; etching to remove the first lead which is not covered by the second part; removing the etching protection film; and carrying out OSP processing on the OSP bonding pad. According to the manufacturing method of the circuit board and the circuit board provided by the invention, the lead can be ensured to be etched cleanly, and the length of the suspended nickel gold is ensured to be within a qualified range.

Description

Technical Field

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

[0002] Data center network card electronic products, such as smart network cards and high-end expansion cards, are developing rapidly. These products mostly use gold finger designs, and signal transmission between products is carried out through gold fingers. Surface treatments are also divided into nickel-palladium-gold and electroplated nickel-gold plus OSP (Organic Solderability Preservative) treatments based on design requirements.

[0003] When the surface treatment is electroplated nickel gold plus OSP treatment, the gold finger leads need to be removed after electroplating nickel gold. Currently, the leads are generally removed by etching. Etching the leads not only requires ensuring that the leads are etched cleanly, but also requires that the length of the overhanging nickel gold above the leads is within the qualified range. Summary of the Invention

[0004] The present application provides a method for manufacturing a circuit board and a circuit board, which can ensure that the lead is etched cleanly and that the length of the nickel-gold overhang is within an acceptable range.

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

[0006] Providing a substrate, the substrate having a circuit layer, the substrate being provided with gold fingers, electroplated leads, and OSP pads, the gold fingers, the electroplated leads, and the OSP pads being formed on the circuit layer, the gold fingers being covered with a nickel-gold layer, the gold fingers including a first finger, the electroplated leads including a first lead, the first finger being connected to the first lead and being electrically conductive;

[0007] An etching protection film is attached to the circuit layer, wherein the etching protection film includes a first protection portion, the first protection portion includes a first portion and a second portion connected to each other, the first portion covers the nickel-gold layer on the first finger, the second portion covers a portion of the first lead, and the middle portion of the second portion away from the end of the first portion is recessed toward the first portion;

[0008] etching and removing the first lead not covered by the second portion;

[0009] removing the etching protection film;

[0010] Performing OSP treatment on the OSP pad.

[0011] In some embodiments, the middle portion of the second part away from one end of the first part is recessed towards the first part.

[0012] In some embodiments, the middle portion of the second part away from one end of the first part is recessed towards the first part by a depth of 10-15um.

[0013] In some embodiments, the area of the nickel-gold layer is K, the area of the first lead covered by the second part is L, the ratio of K to L is M, and the size of the second part along the distribution direction of the first part and the second part is H, H is positively correlated with M.

[0014] In some embodiments, the size of the second part along the distribution direction of the first part and the second part is H; the gold finger further comprises a second finger and a third finger, and the electroplated lead further comprises a second lead and a third lead, the second finger is connected to the second lead and electrically conductive, and the third finger is connected to the third lead and electrically conductive.

[0015] The etching protection film comprises a second protection part and a third protection part, the second protection part comprises a third part and a fourth part connected, the third part covers the nickel-gold layer on the second finger, the fourth part covers part of the second lead, and the middle portion of the fourth part away from one end of the third part is recessed towards the third part, the size of the fourth part along the distribution direction of the third part and the fourth part is H+H0, the third protection part comprises a fifth part and a sixth part connected, the fifth part covers the nickel-gold layer on the third finger, the sixth part covers part of the third lead, and the middle portion of the sixth part away from one end of the fifth part is recessed towards the fifth part, the size of the sixth part along the distribution direction of the fifth part and the sixth part is H+2*H0.

[0016] When etching to remove the first lead not covered by the second part, the second lead not covered by the fourth part and the third lead not covered by the sixth part are etched and removed.

[0017] In some embodiments, before the substrate is provided, the manufacturing method of the circuit board further comprises:

[0018] A press plate is provided, the press plate has a metal layer;

[0019] A finger pad, the electroplated lead and the OSP pad are made on the metal layer;

[0020] An anti-electroplated gold protection film is used to cover the area of the metal layer except the finger pad;

[0021] Performing nickel-gold electroplating on the finger pads through the electroplating leads, so that the finger pads are covered with the nickel-gold layer to obtain the gold fingers;

[0022] The anti-electroplating gold protective film is removed to obtain the substrate.

[0023] In some embodiments, when the finger pads, the electroplating leads and the OSP pads are produced on the metal layer, an auxiliary pad is produced on the metal layer; the anti-electroplating gold protective film is provided with an auxiliary window, and the auxiliary window exposes part of the auxiliary pad; when the finger pads are electroplated with nickel gold through the electroplating leads, the auxiliary pads exposed by the auxiliary window are covered with the electroplated nickel gold PAD; when the etching protective film is attached to the circuit layer, the electroplated nickel gold PAD is used as a positioning reference.

[0024] In some embodiments, the auxiliary pad and the auxiliary window are both circular in shape.

[0025] In some embodiments, the diameter of the auxiliary pad is 1.5 mm-2.0 mm, and the diameter of the auxiliary window is 1.00 mm-1.25 mm.

[0026] In a second aspect, an embodiment of the present application provides a circuit board, which is processed by the circuit board manufacturing method as described in the first aspect.

[0027] The method for manufacturing a circuit board provided in the embodiment of the present application has the beneficial effect that: since the etching protection film includes a first protection part, the first protection part includes a first part and a second part connected to each other, the first part covers the nickel-gold layer on the first finger, the second part covers part of the first lead, and the middle part of the second part away from the end of the first part is recessed toward the first part, so when the first lead not covered by the second part is etched away, it can be ensured that the end of the remaining first lead away from the first finger is flush and does not present a pointed shape with a raised middle part, so that after the OSP pad is OSP treated, it can be ensured that the first lead is etched cleanly and the length of the suspended nickel-gold is within the qualified range.

[0028] The beneficial effects of the circuit board provided in this application compared to the prior art can be referred to the description of the beneficial effects of the manufacturing method of the circuit board provided in this application compared to the prior art, which will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] 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.

[0030] Figure 1 It is a schematic diagram of the structure of gold fingers and electroplated leads in the prior art;

[0031] Figure 2 yes Figure 1 The schematic diagram of the gold fingers and plated leads after OSP treatment is shown;

[0032] Figure 3 yes Figure 1 Another schematic diagram of the gold fingers and plated leads after OSP treatment;

[0033] Figure 4 yes Figure 3 The cross-sectional view corresponding to the gold finger shown;

[0034] Figure 5 It is a schematic diagram of the alignment of the etching protection film and the anti-electroplating gold protection film in the prior art;

[0035] Figure 6 This is a flow chart of a method for manufacturing a circuit board in one embodiment of the present application;

[0036] Figure 7 This is a schematic structural diagram of a first finger, a first lead, and a first protection portion in one embodiment of the present application;

[0037] Figure 8 yes Figure 7 A partial enlarged view of the first finger, the first lead and the first protection portion shown;

[0038] Figure 9 Etching removal Figure 7 A schematic diagram of a first lead not covered by the second portion;

[0039] Figure 10 yes Figure 9 Schematic diagram of the first finger after OSP treatment;

[0040] Figure 11 yes Figure 10 The cross-sectional view corresponding to the gold finger shown;

[0041] Figure 12 This is a schematic diagram of the first finger and first lead structure in one embodiment of the present application;

[0042] Figure 13 This is a schematic diagram of the structure of the first finger and the first lead in another embodiment of the present application;

[0043] Figure 14 This is a schematic diagram of the structure of the first finger and the first lead in another embodiment of the present application;

[0044] Figure 15 This is a schematic diagram of the structure of a first finger, a first lead, a second finger, a second lead, a third finger, and a third lead in one embodiment of the present application;

[0045] Figure 16 yes Figure 15 Schematic diagram of the first finger, the first lead, the second finger, the second lead, the third finger and the third lead after OSP treatment;

[0046] Figure 17 This is a schematic diagram of the alignment of the etching protection film and the anti-electroplating gold protection film in one of the embodiments of the present application.

[0047] The meanings of the marks in the figure are:

[0048] 1. Gold finger; 2. Lead; 3. Nickel-gold layer; 4. Curing sheet; 5. Mechanical hole;

[0049] 100. Substrate;

[0050] 10. First finger; 11. Nickel-gold layer; 20. First lead; 30. Etching protection film; 31. First part; 32. Second part; 40. Curing sheet; 50. OSP pad; 60. Connecting line; 70. Second finger; 71. Second lead; 80. Third finger; 81. Third lead; 90. Auxiliary pad; 91. Electroplated nickel-gold PAD. DETAILED DESCRIPTION

[0051] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and 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.

[0052] It should be noted that when an element is referred to as being “fixed on” or “disposed on” another element, it may 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 may be directly connected to the other element or indirectly connected to the other element.

[0053] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. Throughout the description of this application, "plurality" means two or more, unless otherwise specifically defined.

[0054] References to "one embodiment," "some embodiments," or "an embodiment" in this specification mean that a particular feature, structure, or characteristic described in conjunction with that embodiment is included in one or more embodiments of the present invention. Thus, phrases such as "in one embodiment," "in some embodiments," "in other embodiments," and "in other embodiments" appearing in various places in this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. Furthermore, in one or more embodiments, particular features, structures, or characteristics may be combined in any suitable manner.

[0055] In order to illustrate the technical solution of the present application, the following description is given with reference to specific drawings and embodiments.

[0056] Data center network card-type electronic products are developing rapidly, such as smart network cards and high-end expansion cards. Most of these products are designed with gold fingers, and signal transmission between products is carried out through gold fingers. The surface treatment is also divided into nickel-palladium-gold and electroplated nickel-gold plus OSP treatment according to design requirements.

[0057] When the surface treatment is electroplated nickel gold plus OSP treatment, the gold finger leads need to be removed after electroplating nickel gold. Currently, the leads are generally removed by etching. Etching the leads not only requires ensuring that the leads are etched cleanly, but also requires that the length of the overhanging nickel gold above the leads is within the qualified range.

[0058] In the related art, the amount of side etching is obtained through experiments by slicing, and the dry film covering of the etched circuit is compensated by the corresponding length to ensure that the length of the nickel-gold overhang after etching is within the qualified range. However, this solution is only applicable to circuit board products with electroplated nickel-gold. For circuit boards with electroplated nickel-gold and OSP, when OSP is produced, due to the inconsistent amount of copper bitten by the Giovanni effect of different gold finger designs, it is impossible to ensure that the lead is etched cleanly and the length of the nickel-gold overhang is within the qualified range through the same dry film covering length. In addition, the slicing method is used to ensure the length of the nickel-gold overhang after etching the lead. Each batch needs to be verified separately, which is inefficient and will lead to scrap.

[0059] Please refer to Figures 1 to 4When the dry film covers the lead 2, if the area covered by the dry film is designed to be flush, when etching the lead 2, the exchange rate of the solution on both sides of the lead 2 is better than the exchange rate of the solution on the top of the lead 2. When etching the lead 2, the solution will be corroded from both sides of the lead 2 to the middle. When the lead 2 is etched off, it will appear as a pointed tip with a raised middle part. As the etching continues, the solution exchange in each area is even, and the difference in the amount of corrosion between the pointed tip and the rest of the area is small. After the corrosion is completed, the middle area of ​​the lead 2 will be protruding.

[0060] If the lead 2 of the gold finger 1 is protruding, the length of the nickel-gold layer 3 in some areas is qualified, but there is still some area where the lead 2 remains (such as Figure 2 As shown, the length of A1 nickel-gold suspension is qualified, but the length of B2 lead wire 2 is left), or the nickel-gold suspension is qualified in some areas, but out of tolerance in others (such as Figure 3 As shown, the length of the nickel-gold overhang at position A2 is unqualified, but the length of the nickel-gold overhang at position B2 is qualified). It cannot be guaranteed that the length of the nickel-gold overhang at the raised area of ​​the original etched lead 2 and the length of the nickel-gold overhang at the non-raised area are both qualified.

[0061] On the other hand, please refer to Figure 5 Generally, the area of ​​the circuit board except for the finger pads is first covered with an electroplating-resistant gold protective film, and then the finger pads are electroplated with nickel-gold through the leads 2, so that the finger pads are covered with a nickel-gold layer 3 to obtain gold fingers 1. However, when the electroplating-resistant gold protective film is used to cover the area of ​​the circuit board except for the finger pads, the mechanical holes 5 on the circuit board are often used. There is a deviation between the electroplating nickel-gold position and the theoretical position. When the dry film is attached to the circuit board as an etching protective film, the same mechanical holes 5 as the electroplating-resistant gold protective film are still used for alignment. The alignment deviation is superimposed, and it is impossible to ensure that the length of the dry film covering the leads 2 is within the required range. Figure 5 As shown in the figure, when the anti-electroplating nickel-gold protective film is misaligned, the front end position of the gold finger 1 is offset. When the mechanical hole 5 is still used for alignment in the production of the etching protective film, there is a secondary misalignment, resulting in that the etching protective film should theoretically cover the lead 2 for a length of L1, but in fact the lead 2 is only covered for a length of L2, where L2 is less than L1.

[0062] In view of this, the present application provides a method for manufacturing a circuit board and a circuit board. Since the etching protection film includes a first protective part, the first protective part includes a first part and a second part connected to each other, the first part covers the nickel-gold layer on the first finger, the second part covers part of the first lead, and the middle part of the second part away from the end of the first part is recessed toward the first part. Therefore, when etching away the first lead not covered by the second part, it can be ensured that the end of the remaining first lead away from the first finger is flush and does not present a pointed shape with a raised middle part. Therefore, after the OSP pad is OSP treated, it can be ensured that the first lead is etched cleanly and the length of the suspended nickel-gold is within the qualified range.

[0063] Please refer to Figures 6 to 11 In a first aspect, an embodiment of the present application provides a method for manufacturing a circuit board, comprising:

[0064] S100: Provide a substrate 100, the substrate 100 has a circuit layer, the substrate 100 is provided with a gold finger, an electroplated lead and an OSP pad 50, the gold finger, the electroplated lead and the OSP pad 50 are all formed on the circuit layer, the gold finger is covered with a nickel-gold layer 11, the gold finger includes a first finger 10, the electroplated lead includes a first lead 20, the first finger 10 is connected to the first lead 20 and is electrically conductive.

[0065] Specifically, the substrate 100 may include a curing sheet 40 and a circuit layer, and the circuit layer may be a copper layer, etc. The nickel-gold layer 11 may include a gold layer and a nickel layer.

[0066] S200: Attach an etching protection film 30 to the circuit layer, the etching protection film 30 includes a first protection portion, the first protection portion includes a first portion 31 and a second portion 32 connected to each other, the first portion 31 covers the nickel-gold layer 11 on the first finger 10, the second portion 32 covers a portion of the first lead 20, and the second portion 32 is recessed in a direction close to the first portion 31 away from the middle of one end of the first portion 31.

[0067] Specifically, the etching protection film 30 can be a dry film, etc. An LDI (Laser Direct Imaging) exposure machine can be used to ensure that the first portion 31 covers the nickel-gold layer 11 on the first finger 10, the second portion 32 covers a portion of the first lead 20, and the OSP pad 50 and other circuits are covered and protected by the etching protection film 30.

[0068] S300 : etching and removing the first lead 20 not covered by the second portion 32 .

[0069] Specifically, the window openings in the first lead 20 not covered by the second portion 32 are removed by chemical etching. Because the middle portion of the end of the second portion 32 away from the first portion 31 is recessed toward the first portion 31, this prevents the end of the second portion 32 from protruding due to varying amounts of etching at different locations on the end away from the first portion 31.

[0070] S400 : removing the etching protection film 30 .

[0071] Specifically, the etching protection film 30 can be removed by stripping the film. After removing the etching protection film 30, the larger substrate 100 can be gonged into the required size by mechanical gong, and the finished board can be tested for electrical properties.

[0072] S500 : performing OSP treatment on the OSP pad 50 .

[0073] Specifically, the substrate 100 can be immersed in OSP solution to form an organic film on the OSP pad 50. Due to the Galvani effect, the first lead 20 covered by the second portion 32 is etched away, ensuring that the first lead 20 is etched cleanly and the length of the overhanging nickel-gold is within the qualified range.

[0074] From the above, it can be seen that the method for manufacturing a circuit board provided in the embodiment of the present application is that the etching protection film 30 includes a first protection part, the first protection part includes a first part 31 and a second part 32 connected to each other, the first part 31 covers the nickel-gold layer 11 on the first finger 10, and the second part 32 covers part of the first lead 20, and the middle part of the second part 32 away from the end of the first part 31 is recessed in the direction close to the first part 31. Therefore, when the first lead 20 not covered by the second part 32 is etched away, it can be ensured that the remaining first lead 20 is flush with the end away from the first finger 10 and does not present a pointed tip with a raised middle part. Therefore, after the OSP pad 50 is OSP treated, it can be ensured that the first lead 20 is etched cleanly and the length of the suspended nickel-gold is within the qualified range.

[0075] After the OSP pad 50 is subjected to the OSP treatment, subsequent processes such as FQC (Final Quality Control), FQA (Factory Quality Assurance), and packaging may be completed in sequence.

[0076] Optionally, a middle portion of the second portion 32 at one end away from the first portion 31 is concave in an arc shape toward the first portion 31 .

[0077] With this arrangement, when etching away the first lead 20 not covered by the second portion 32 , it can be ensured that the remaining first lead 20 away from the first finger 10 is flush with the end thereof and does not present a pointed shape with a raised middle portion.

[0078] Optionally, a depth D1 of the middle portion of the second portion 32 at one end away from the first portion 31 and recessed toward the first portion 31 is 10um-15um, such as 10um, 11um, 12um, 13um, 14um or 15um.

[0079] With this arrangement, when etching away the first lead 20 not covered by the second portion 32 , it can be ensured that the remaining first lead 20 away from the first finger 10 is flush with the end thereof and does not present a pointed shape with a raised middle portion.

[0080] It should be noted that the depth D1 of the depression in the middle of the end of the second portion 32 away from the first portion 31 toward the first portion 31 is determined by the width of the first lead 20 and the etching amount. A circle is drawn through the two end points of the second portion 32 that contact the first lead 20 and the point at the bottom of the depth, with the arc at the bottom retained, to achieve the desired concave design of the middle of the end of the second portion 32 away from the first portion 31.

[0081] Please refer to Figures 12 to 14 In some embodiments, the area of ​​the nickel-gold layer 11 is K, the area of ​​the first lead 20 covered by the second portion 32 is L, the ratio of K to L is M, the size of the second portion 32 along the distribution direction of the first portion 31 and the second portion 32 is H, and H is positively correlated with M.

[0082] By adopting the above solution, the size of the second portion 32 along the distribution direction of the first portion 31 and the second portion 32 can be dynamically adjusted according to the ratio of the area of ​​the nickel-gold layer 11 to the area of ​​the electroplated lead covered by the second portion 32.

[0083] Here, H=the side etch amount H1 of the first lead 20 + the OSP Galvani bite amount H2, wherein H1 is a constant value. The side etch amount can be ensured to be H1 by adjusting the etching parameters, that is, the residual amount of the first lead 20 after etching can be ensured to be the OSP Galvani bite amount H2.

[0084] The amount of Giovanni corrosion H2 is related to the gold-copper ratio (the area of ​​the nickel-gold layer 11 and the area of ​​the electroplated lead covered by the second part 32). Under the same OSP parameters, the larger the gold-copper ratio, the greater the copper corrosion. Theoretically, under the same gold-copper ratio, the amount of corrosion of the first lead 20 after OSP treatment is the same. In the embodiment of the present application, for the convenience of calculation, under the premise of a fixed gold finger lead width, after OSP treatment according to a gold-copper ratio of 200:1, the loss area S1 of the first lead 20 caused by the Giovanni effect is called the basic corrosion amount. The lead length corresponding to the basic corrosion amount is H3 = 10um. When the gold finger sizes are different, or the gold finger is connected to the OSP pad 50 (at this time, the copper area is the gold finger lead residual area + the OSP pad 50 area), the copper surface area will also change, and the different gold finger areas are compared with the basic corrosion area S1. For example, when the gold-copper ratio is ≤200:1, the Giovanni corrosion amount H2=H3; when the gold-copper ratio is greater than 200:1 and the gold-copper ratio is ≤200:1, the Giovanni corrosion amount H2=H3+5um; when the gold-copper ratio is greater than 300:1 and the gold-copper ratio is ≤400:1, the Giovanni corrosion amount H2=H3+10um; when the gold-copper ratio is greater than 400:1 and the gold-copper ratio is ≤500:1, the Giovanni corrosion amount H2=H3+15um.

[0085] According to the actual case analysis, the corresponding bite etching amount will increase 5um for every increase of 100:1 in the gold-copper ratio, and finally the Jovani bite etching amount H2 is determined, combined with the etching side etching amount H1 of the first lead 20, to determine H.

[0086] As shown in the drawings, Figure 12 in an embodiment, the gold finger is connected with the OSP pad 50 through the connecting line 60, the area of the copper is the area of the first lead 20 covered by the second part 32 plus the area of the OSP pad 50, and the corresponding gold-copper ratio is 160:1, and the Jovani bite etching amount is H2=10um.

[0087] As shown in the drawings, Figure 13 in an embodiment, the gold finger is not connected with the OSP pad 50, and the size of the gold finger is small, the gold-copper ratio is 230:1, and at this time H2=H3+5um, which is 15um.

[0088] As shown in the drawings, Figure 14 in an embodiment, the gold finger is not connected with the OSP pad 50, and the size of the gold finger is large, the gold-copper ratio is 450:1, and at this time H2=H3+15um, which is 25um.

[0089] Please refer to Figure 15 and Figure 16 in some embodiments, the size of the second part 32 along the distribution direction of the first part 31 and the second part 32 is H; the gold finger further includes a second finger 70 and a third finger 80, and the electroplated lead further includes a second lead 71 and a third lead 81, the second finger 70 is connected with the second lead 71 and electrically connected, and the third finger 80 is connected with the third lead 81 and electrically connected.

[0090] The etching protection film 30 includes a second protection part and a third protection part, the second protection part includes a third part and a fourth part connected with each other, the third part covers the nickel-gold layer 11 on the second finger 70, the fourth part covers part of the second lead 71, and the middle part of the end of the fourth part away from the third part is recessed in the direction close to the third part, the size of the fourth part along the distribution direction of the third part and the fourth part is H+H0, the third protection part includes a fifth part and a sixth part connected with each other, the fifth part covers the nickel-gold layer 11 on the third finger 80, the sixth part covers part of the third lead 81, and the middle part of the end of the sixth part away from the fifth part is recessed in the direction close to the fifth part, the size of the sixth part along the distribution direction of the fifth part and the sixth part is H+2*H0.

[0091] When the first lead 20 not covered by the second part 32 is etched and removed, the second lead 71 not covered by the fourth part and the third lead 81 not covered by the sixth part are etched and removed.

[0092] By adopting the above solution, after OSP treatment of the OSP pad 50, the residual state of the second lead 71 corresponding to the second finger 70 and the residual state of the third lead 81 corresponding to the third finger 80 can be observed to determine the nickel-gold hanging state corresponding to the first finger 10. The OSP parameters can be adjusted based on the result to ensure that the nickel-gold hanging length of different gold fingers is within the specification range and no first lead 20 remains, without the need for destructive slicing.

[0093] It should be noted that both the second finger 70 and the third finger 80 can be arranged on the broken edge of the substrate 100 .

[0094] For example, when H0=5um, if the first lead 20 exists after the OSP pad 50 is OSP treated, it means that the OSP treatment has not achieved the set Galvani effect, and the OSP parameters should be adjusted to increase the Galvani effect; if the first lead 20 remains after the OSP pad 50 is OSP treated, and the second lead 71 and / or the third lead 81 have no lead residues, it proves that the Galvani effect is serious and there is a risk of excessive length of the suspended nickel gold. The OSP parameters should be appropriately adjusted to reduce the Galvani effect until the second lead 71 remains 5um and the third lead 81 remains 10um, which proves that the OSP parameters are reasonable and can be mass-produced, and there is no need to perform slicing to confirm the suspended nickel gold effect.

[0095] It should be noted that adjusting the OSP parameters can adjust the concentration of the OSP solution or the time of OSP treatment.

[0096] Please refer to Figure 17 In some embodiments, before providing the substrate 100, the method for manufacturing the circuit board further includes:

[0097] First, a press plate is provided, wherein the press plate has a metal layer.

[0098] Specifically, the laminate can be manufactured through the normal process of pre-processing, such as cutting, inner layer circuit, AOI (Automated Optical Inspection), lamination, drilling, milling, drilling and filling.

[0099] Next, finger pads, electroplated leads and OSP pads 50 are fabricated on the metal layer.

[0100] Next, use an electroplating-resistant gold protective film to cover the metal layer except for the finger pads. An LDI exposure machine can be used to expose the finger pads.

[0101] Next, the finger pads are electroplated with nickel-gold through electroplating leads, so that the finger pads are covered with a nickel-gold layer 11 to obtain gold fingers.

[0102] Specifically, a nickel layer and a gold layer of target thickness are plated on the finger pads exposed through the openings of the anti-electroplating gold protective film through chemical reaction.

[0103] Then, the electroplating gold resist film is removed to obtain the substrate 100 .

[0104] By adopting the above solution, the substrate 100 can be manufactured more conveniently.

[0105] It should be noted that the anti-gold plating protective film can be a dry film, etc. When the finger pads, plated leads, and OSP pads 50 are fabricated on the metal layer, other circuits can be fabricated simultaneously. After removing the anti-gold plating protective film to obtain the substrate 100, the substrate 100 is screen-printed with ink, pre-baked, exposed, and developed. The portion required for plugging and soldering (the area where the OSP pads 50 are located) is windowed, and the remaining portion is protected with ink. Note that windowing is required for the plated leads and auxiliary pads 90 for nickel-gold electroplating.

[0106] Among them, when finger pads, electroplated leads and OSP pads 50 are made on the metal layer, auxiliary pads 90 are made on the metal layer; the anti-electroplating gold protective film is provided with auxiliary windows, and the auxiliary windows expose part of the auxiliary pads 90; when the finger pads are electroplated with nickel gold through the electroplated leads, the auxiliary pads 90 exposed by the auxiliary windows are covered with electroplated nickel gold PAD91; when the etching protective film 30 is attached to the circuit layer, the electroplated nickel gold PAD91 is used as a positioning reference.

[0107] By adopting the above-mentioned solution, the attachment accuracy of the etching protection film 30 can be improved, the alignment deviation between the nickel-gold layer 11 and the etching protection film 30 caused by the use of traditional mechanical hole alignment can be reduced, and the deviation between the actual length of the etching protection film 30 covering the first lead 20 and the theoretical covering length can be reduced. The length L3 of the etching protection film 30 covering the first lead 20 will be close to the theoretical length L1 of the lead that the etching protection film 30 should cover.

[0108] Optionally, the shapes of the auxiliary pad 90 and the auxiliary window are both set to be circular.

[0109] Such an arrangement facilitates the production of the auxiliary pad 90 and the auxiliary window.

[0110] Optionally, the diameter of the auxiliary pad 90 is 1.5mm-2.0mm, such as 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm or 2.0mm, and the diameter of the auxiliary window is 1.00mm-1.25mm, such as 1.00mm, 1.05mm, 1.10mm, 1.15mm, 1.20mm or 1.25mm.

[0111] Such a configuration facilitates the production of the auxiliary pad 90 and the auxiliary window, and facilitates covering the auxiliary pad 90 exposed by the auxiliary window with the electroplated nickel-gold PAD 91.

[0112] It should be noted that the auxiliary pad 90 can be a copper PAD provided in the copper grid area (connected to the electroplating clamping point) at the edge of the press plate. The auxiliary window can be provided at the center of the auxiliary pad 90 .

[0113] In a second aspect, an embodiment of the present application provides a circuit board, which is processed by the circuit board manufacturing method of the first aspect.

[0114] In the circuit board provided in the embodiment of the present application, the etching protection film 30 includes a first protection portion, the first protection portion includes a first portion 31 and a second portion 32 connected to each other, the first portion 31 covers the nickel-gold layer 11 on the first finger 10, the second portion 32 covers a portion of the first lead 20, and the middle portion of the second portion 32 at one end away from the first portion 31 is recessed toward the first portion 31. Therefore, when the first lead 20 not covered by the second portion 32 is etched away, it can be ensured that the end of the remaining first lead 20 away from the first finger 10 is flush and does not present a pointed shape with a raised middle portion. Therefore, after the OSP pad 50 is OSP treated, it can be ensured that the lead is etched cleanly and the length of the overhanging nickel-gold is within the qualified range.

[0115] 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 substrate, the substrate having a circuit layer, the substrate being provided with gold fingers, electroplated leads, and OSP pads, the gold fingers, the electroplated leads, and the OSP pads being formed on the circuit layer, the gold fingers being covered with a nickel-gold layer, the gold fingers including a first finger, the electroplated leads including a first lead, the first finger being connected to the first lead and being electrically conductive; An etching protection film is attached to the circuit layer, wherein the etching protection film includes a first protection portion, the first protection portion includes a first portion and a second portion connected to each other, the first portion covers the nickel-gold layer on the first finger, the second portion covers a portion of the first lead, and the middle portion of the second portion away from the end of the first portion is recessed toward the first portion; etching and removing the first lead not covered by the second portion; removing the etching protection film; The OSP pad is subjected to OSP treatment.

2. The method for manufacturing a circuit board according to claim 1, wherein: A middle portion of an end of the second portion away from the first portion is concave in an arc shape toward the first portion.

3. The method for manufacturing a circuit board according to claim 2, wherein: A middle portion of the second portion at one end away from the first portion is recessed in a direction closer to the first portion by a depth of 10 μm to 15 μm.

4. The method for manufacturing a circuit board according to claim 1, wherein: The area of ​​the nickel-gold layer is K, the area of ​​the first lead covered by the second part is L, the ratio of K to L is M, the size of the second part along the distribution direction of the first part and the second part is H, and H is positively correlated with M.

5. The method for manufacturing a circuit board according to claim 1, wherein: The dimension of the second portion along the distribution direction of the first portion and the second portion is H; the gold finger further includes a second finger and a third finger, the electroplating lead further includes a second lead and a third lead, the second finger is connected to the second lead and is electrically conductive, and the third finger is connected to the third lead and is electrically conductive; The etching protection film includes a second protection portion and a third protection portion, the second protection portion includes a third portion and a fourth portion connected thereto, the third portion covers the nickel-gold layer on the second finger, the fourth portion covers a portion of the second lead, and a middle portion of the fourth portion away from one end of the third portion is recessed toward the third portion, and a dimension of the fourth portion along a distribution direction between the third portion and the fourth portion is H+H0; the third protection portion includes a fifth portion and a sixth portion connected thereto, the fifth portion covers the nickel-gold layer on the third finger, the sixth portion covers a portion of the third lead, and a middle portion of the sixth portion away from one end of the fifth portion is recessed toward the fifth portion, and a dimension of the sixth portion along a distribution direction between the fifth portion and the sixth portion is H+2*H0; When the first lead not covered by the second portion is etched away, the second lead not covered by the fourth portion and the third lead not covered by the sixth portion are etched away.

6. The method for manufacturing a circuit board according to any one of claims 1 to 5, characterized in that: Before providing the substrate, the method for manufacturing the circuit board further includes: providing a press plate having a metal layer; Fabricating finger pads, the electroplating leads and the OSP pads on the metal layer; Covering the area of ​​the metal layer except the finger pads with an anti-electroplating gold protective film; Performing nickel-gold electroplating on the finger pads through the electroplating leads, so that the finger pads are covered with the nickel-gold layer to obtain the gold fingers; The anti-electroplating gold protective film is removed to obtain the substrate.

7. The method for manufacturing a circuit board according to claim 6, wherein: When the finger pads, the electroplating leads and the OSP pads are produced on the metal layer, auxiliary pads are produced on the metal layer; the anti-electroplating gold protective film is provided with auxiliary windows, and the auxiliary windows expose part of the auxiliary pads; when the finger pads are electroplated with nickel gold through the electroplating leads, the auxiliary pads exposed by the auxiliary windows are covered with the electroplated nickel gold PAD; when the etching protective film is attached to the circuit layer, the electroplated nickel gold PAD is used as a positioning reference.

8. The method for manufacturing a circuit board according to claim 7, wherein: The shapes of the auxiliary pad and the auxiliary window are both set to be circular.

9. The method for manufacturing a circuit board according to claim 8, wherein: The diameter of the auxiliary pad is 1.5mm-2.0mm, and the diameter of the auxiliary window is 1.00mm-1.25mm.

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

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