Method for manufacturing a gold finger circuit board and gold finger circuit board

Abstract

The embodiment of the application provides a manufacturing method of a golden finger circuit board and the golden finger circuit board. It relates to the field of circuit board processing technology. The method comprises the following steps: obtaining a to-be-processed circuit board; plating copper on the surface of the to-be-processed circuit board, and plating gold in the golden finger area of the to-be-processed circuit board, the length of the golden finger area being greater than or equal to a first threshold value; pasting dry film on the surface of a first area of the to-be-processed circuit board, the first area comprising a circuit area, a golden finger area and a first temporary lead area, the length of the first temporary lead area being less than or equal to a second threshold value; exposing the circuit area and the golden finger area, and developing the to-be-processed circuit board; and etching the to-be-processed circuit board to obtain the golden finger circuit board. The stability of data transmission can be improved.

Description

Technical Field

[0001] This application relates to the field of circuit board processing technology, and in particular to a method for manufacturing a gold finger circuit board and the gold finger circuit board. Background Technology

[0002] With the rapid development of technologies such as artificial intelligence, the Internet of Things, and high-performance computing, the interfaces of electronic devices need to be frequently plugged and unplugged to achieve modular maintenance or dynamic expansion of functions.

[0003] Currently, gold finger circuit boards are typically integrated into electronic devices. As components with detachable electrical connections, gold finger circuit boards can meet the frequent plugging and unplugging requirements of electronic device interfaces. However, in scenarios involving high-frequency and high-speed data transmission, existing gold finger circuit boards may have problems such as short circuits and weak crosstalk suppression capabilities, resulting in poor data transmission stability. Summary of the Invention

[0004] This application provides a method for manufacturing a gold finger circuit board and a gold finger circuit board, which can improve the stability of data transmission.

[0005] In a first aspect, embodiments of this application provide a method for manufacturing a gold finger circuit board, comprising:

[0006] Obtain the circuit board to be processed;

[0007] Copper is plated on the surface of the circuit board to be processed, and gold is plated in the gold finger area of ​​the circuit board to be processed, wherein the length of the gold finger area is greater than or equal to a first threshold.

[0008] A dry film is applied to the surface of a first region of the circuit board to be processed. The first region includes a circuit region, a gold finger region, and a first temporary lead region. The length of the first temporary lead region is less than or equal to a second threshold.

[0009] The circuit area and gold finger area are exposed, and the circuit board to be processed is developed.

[0010] The circuit board to be processed is etched to obtain the gold finger circuit board.

[0011] In one possible implementation, the circuit board to be processed includes multiple panel units, each panel unit including multiple preset cursor points, the cursor points being used to locate and mark each panel unit, and gold plating in the gold finger area of ​​the circuit board to be processed includes:

[0012] Based on multiple cursor points in each panel unit, the circuit board to be processed is sequentially subjected to roughening, wet film printing, and dry film gold plating.

[0013] Nickel and gold layers are plated sequentially in the gold finger area, and the dry gold film on the surface of the circuit board to be treated is cleaned.

[0014] In one possible implementation, the circuit board to be processed is coarsened based on multiple cursor points of each panel unit, including:

[0015] Polishing is performed on the surface of the circuit board to be processed. Polishing is used to clean and smooth the surface of the circuit board to be processed.

[0016] The surface of the circuit board to be processed is roughened to increase the surface roughness of the circuit board.

[0017] Dry film is applied to the surface of the circuit board to be treated, and the surface of the circuit board to be treated is subjected to air pressure treatment. Air pressure treatment is used to enhance the adhesion between the dry film and the surface of the circuit board to be treated.

[0018] Based on multiple cursor points of each panel unit, the second area of ​​the circuit board to be processed is exposed. The second area includes the gold finger area, the second temporary lead area and each line in the line area. The second temporary lead area includes the first temporary lead area.

[0019] The surface of the circuit board to be processed is developed and acid-etched.

[0020] In one possible implementation, based on multiple cursor points of each panel unit, a wet film printing process is performed on the circuit board to be processed, including:

[0021] Apply a wet film to the surface of the circuit board to be processed;

[0022] Based on multiple cursor points in each panel unit, the circuit area and the second temporary lead area are exposed;

[0023] The surface of the circuit board to be processed is developed.

[0024] In one possible implementation, based on multiple cursor points of each panel unit, a printed gold-plated dry film process is performed on the circuit board to be processed, including:

[0025] Apply a gold-plated dry film to the surface of the circuit board to be processed;

[0026] The gold finger area is exposed based on multiple cursor points of each panel unit;

[0027] The surface of the circuit board to be processed is developed.

[0028] In one possible implementation, copper plating is performed on the surface of the circuit board to be processed, including:

[0029] Obtain electroplating information, which includes one or more of the following: electroplating current, electroplating duration, electroplating temperature, and electroplating solution concentration;

[0030] Based on the electroplating information, copper is plated on the surface of the circuit board to be processed.

[0031] In one possible implementation, etching the circuit board to be processed includes:

[0032] Spray an alkaline etching solution onto the surface of the circuit board to be processed;

[0033] The dry film on the surface of the first area is cleaned.

[0034] In one possible implementation, before applying a dry film to the surface of a first region of the circuit board to be processed, the method further includes:

[0035] The surface of the circuit board to be treated is washed with water using volcanic ash.

[0036] In one possible implementation, after etching the circuit board to be processed to obtain a gold finger circuit board, the method further includes:

[0037] Sandblasting is performed on the gold finger circuit board;

[0038] Apply green solder mask to the surface of the gold finger circuit board;

[0039] The third region of the gold finger circuit board is exposed and developed. The third region includes the area outside the lines in the gold finger area and the circuit area of ​​the gold finger circuit board.

[0040] Secondly, embodiments of this application provide a gold finger circuit board, which is obtained by the gold finger circuit board manufacturing method shown in any of the above claims.

[0041] This application provides a method for manufacturing a gold finger circuit board and a gold finger circuit board. By controlling the length of the gold finger area and the length of the first temporary lead area covered by the dry film, and then etching the circuit board to be processed, the problems of gold layer overflow and excessive gold suspension during the gold plating process can be avoided. Reducing the length of the gold suspension on the gold finger reduces the risk of metal debris falling off and contact short circuits, improves the signal crosstalk suppression capability, improves the stability of high-frequency and high-speed data transmission, and extends the service life of the gold finger circuit board. Attached Figure Description

[0042] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0043] Figure 1 A schematic flowchart illustrating a method for manufacturing a gold finger circuit board according to an embodiment of this application;

[0044] Figure 2 A schematic diagram of a circuit board to be processed provided in an embodiment of this application;

[0045] Figure 3 This is a schematic diagram of a dry film coverage area provided in an embodiment of this application;

[0046] Figure 4 This is a flowchart illustrating a method for gold plating in the gold finger area, as provided in an embodiment of this application.

[0047] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0048] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0049] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties. Furthermore, the collection, storage, use, processing, transmission, provision, disclosure, and application of the relevant data all comply with the relevant laws, regulations, and standards of the relevant countries and regions, have taken necessary confidentiality measures, do not violate public order and good morals, and provide corresponding operation access points for users to choose to authorize or refuse.

[0050] Furthermore, the technical solution involved in this application, which involves big data analysis of user information (including but not limited to personal biometrics, identity data, consumption data, asset data, electronic terminal operation data, etc.) and the use of artificial intelligence technology for automated decision-making, and makes decisions that have a significant impact on personal rights based on the results of automated decision-making, provides users with corresponding operation entry points for users to choose to agree to or reject the results of automated decision-making; if the user chooses to reject, the process will proceed to the expert decision-making process.

[0051] It should be noted that the manufacturing method and the gold finger circuit board provided in this application can be used in the field of circuit board processing technology, or in any field other than the field of circuit board processing technology. The application field of the manufacturing method and the gold finger circuit board in this application is not limited.

[0052] It should be noted that in the embodiments of this application, certain software, components, models and other existing solutions in the industry may be mentioned. These should be regarded as exemplary and are only intended to illustrate the feasibility of implementing the technical solution of this application. However, it does not mean that the applicant has used or necessarily used the solution.

[0053] With the rapid development of technologies such as artificial intelligence, the Internet of Things, and high-performance computing, the interfaces of electronic devices need to be frequently plugged and unplugged to achieve modular maintenance or dynamic expansion of functions.

[0054] Currently, gold finger circuit boards are typically integrated into electronic devices. As components with detachable electrical connections, gold finger circuit boards can meet the frequent plugging and unplugging requirements of electronic device interfaces. However, in scenarios involving high-frequency and high-speed data transmission, existing gold finger circuit boards may have problems such as short circuits and weak crosstalk suppression capabilities, resulting in poor data transmission stability.

[0055] To address the aforementioned issues, this application provides a method for manufacturing a gold finger circuit board, comprising: obtaining a circuit board to be processed; plating copper on the surface of the circuit board to be processed and plating gold in the gold finger region of the circuit board to be processed, wherein the length of the gold finger region is greater than or equal to a first threshold; attaching a dry film to the surface of a first region of the circuit board to be processed, wherein the first region includes a circuit region, a gold finger region, and a first temporary lead region, wherein the length of the first temporary lead region is less than or equal to a second threshold; exposing the circuit region and the gold finger region and developing the circuit board to be processed; and etching the circuit board to be processed to obtain the gold finger circuit board.

[0056] In the above method, by controlling the length of the gold finger area and the length of the first temporary lead area covered by the dry film before etching the circuit board to be processed, the problems of gold layer overflow and excessive gold suspension during the gold plating process can be avoided. Reducing the length of the gold suspension on the gold finger reduces the risk of metal debris falling off and contact short circuit, improves the signal crosstalk suppression capability, improves the stability of high-frequency and high-speed data transmission, and can also extend the service life of the gold finger circuit board.

[0057] The technical solution of this application and how the technical solution of this application solves the above-mentioned technical problems are described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of this application will now be described with reference to the accompanying drawings.

[0058] Figure 1 This is a schematic flowchart illustrating a method for manufacturing a gold finger circuit board according to an embodiment of this application. Please refer to... Figure 1 As shown, the method may include the following steps:

[0059] S101. Obtain the circuit board to be processed.

[0060] In one possible implementation, the circuit board to be processed refers to a circuit board substrate that has completed basic processes such as material cutting, inner layer fabrication, lamination, and drilling, but has not yet undergone key processes such as outer layer circuit fabrication, gold plating, and solder masking.

[0061] In one possible implementation, the circuit board to be processed includes multiple panel units, each panel unit including multiple preset cursor points used for positioning and marking each panel unit. Here, a panel unit refers to the smallest unit in the circuit board to be processed that can be independently divided into finished products. Each panel unit corresponds one-to-one with a router cutter position, which is a preset cutting position for separating the panel unit from the circuit board to be processed.

[0062] In one possible implementation, circular positioning marks (cursor points) can be added to the four corners of the milling cutter position corresponding to the panel unit. The diameter of each cursor point is the same and is a preset diameter, for example, 3 millimeters (mm).

[0063] In one possible implementation, multiple substrates can be cut to the target size, and the multiple substrates can be laminated together. The outermost two sides of the laminated circuit board are made into an anti-corrosion layer. The CCD drill with a camera scans each cursor point of each panel unit to obtain the lamination expansion and contraction information of the circuit board. Based on the lamination expansion and contraction information, the circuit board is drilled to obtain a precisely positioned, offset, and drilled circuit board to be processed.

[0064] In one possible implementation, during the drilling process of the circuit board, a preset number (e.g., 3) of positioning pins can be inserted into the target hole to achieve precise alignment.

[0065] The compression expansion and contraction information includes the dimensional shrinkage and expansion of the substrate after the compression process, as well as the actual offset of each panel unit. The target hole refers to the reference hole pre-processed on the circuit board to be processed, which is used to cooperate with the positioning pin to achieve mechanical positioning. The positioning pin refers to the positioning pin that matches the size of the target hole, which is used to fit the target hole to achieve precise fixation between the circuit board and the processing equipment, and to prevent offset or loosening during the processing.

[0066] In one possible implementation, obtaining the compression expansion and contraction information of the circuit board may include: taking pictures and identifying the cursor points around the corresponding router positions of each panel unit using a CCD drilling machine, obtaining the actual position of each cursor point on the circuit board, comparing the actual position of each cursor point with a preset position, calculating the difference between the actual position and the preset position of each cursor point in the horizontal and vertical directions, and calculating the dimensional shrinkage, dimensional expansion, and actual offset of each panel unit based on the differences of multiple cursor points.

[0067] In one possible implementation, drilling holes in the circuit board based on the compression expansion and contraction information can include: adjusting the preset drilling coordinates in the horizontal and vertical directions according to the dimensional shrinkage, dimensional expansion, and actual offset of each panel unit, in the opposite direction to the actual offset and equal in value to the dimensional shrinkage or dimensional expansion, correcting the target coordinates of the drilling, compensating for the expansion and contraction of the drilling position, so that the drilling position is consistent with the preset position, avoiding hole position displacement caused by substrate deformation during the compression process, and improving the accuracy of the drilling position.

[0068] Among them, the preset position refers to the position of the cursor point in the design file, and the preset drilling coordinates refer to the coordinates of the drilling in the design file.

[0069] S102. Copper is plated on the surface of the circuit board to be processed, and gold is plated in the gold finger area of ​​the circuit board to be processed, wherein the length of the gold finger area is greater than or equal to the first threshold.

[0070] In one possible implementation, copper plating refers to depositing a uniform layer of metallic copper on the surface of the circuit board to be processed through electrochemical means, so that the circuit board to be processed has conductivity, ensuring the conductivity and shaping of subsequent circuits, gold fingers, and temporary leads.

[0071] In one possible implementation, the gold finger area is located at the edge of the circuit board to be processed. It is a conductive contact area for plugging and unplugging. It is arranged in strips, resembling fingers. The surface of the gold finger area needs to be plated with gold to improve wear resistance and conductivity.

[0072] In one possible implementation, the first threshold refers to the lower limit of the length of the gold finger area, which is used to ensure sufficient contact area, reliable insertion and removal, and stable signal transmission. The first threshold is, for example, 8 mils.

[0073] For example, taking a gold finger area with a length of 8 mil as an example, combined with Figure 2 The length of the gold finger area is explained. Figure 2 This is a schematic diagram of a circuit board to be processed provided in an embodiment of this application, as shown below. Figure 2As shown, the circuit board to be processed includes a circuit area, a gold finger area, and a second temporary lead area. The length of the gold finger area is 8 mil, and the width of the second temporary lead area is 8 mil. Detailed descriptions of the circuit area and the second temporary lead area are provided in subsequent embodiments and will not be repeated here.

[0074] In this way, by controlling the length of the gold finger area to be greater than or equal to the first threshold, the effective contact area between the gold finger and the external interface and the reliability of the electrical connection can be guaranteed. Sufficient processing allowance can also be reserved for subsequent gold plating. At the same time, combined with the width design of the second temporary lead area, a stable electroplating conduction path can be provided, avoiding poor conduction or uneven gold plating due to the contact area being too small. This further improves the gold finger forming accuracy and gold suspension control effect, and enhances the stability of high-frequency and high-speed signal transmission.

[0075] In one possible implementation, copper can be electroplated onto the entire surface of the circuit board to be processed, so that a uniform conductive layer is formed on the circuit board.

[0076] In some implementations, copper plating on the surface of the circuit board to be processed can include:

[0077] Obtain electroplating information, which includes one or more of the following: electroplating current, electroplating duration, electroplating temperature, and electroplating solution concentration; based on the electroplating information, plate copper on the surface of the circuit board to be processed.

[0078] In one possible implementation, electroplating information refers to the set of process parameters that affect the quality and efficiency of copper plating.

[0079] In one possible implementation, the electroplating current refers to the magnitude of the current passing through the circuit board to be processed and the electroplating solution during the electroplating process. If the current is too large, it will easily lead to rough copper layer crystals, while if the current is too small, the copper plating efficiency will be too low.

[0080] In one possible implementation, the electroplating time refers to the duration for which the circuit board to be processed is immersed in the electroplating solution and a current is continuously applied to plate copper. If the time is too long, the copper layer will be too thick, and if the time is too short, the copper layer will not reach the target thickness.

[0081] In one possible implementation, the electroplating temperature refers to the temperature of the electroplating solution during the copper plating process. It can affect the activity of the electroplating solution and the rate of copper ion deposition. If the temperature is too high, the electroplating solution will easily decompose, while if the temperature is too low, the copper ion deposition will be slow and the copper layer will be uneven.

[0082] In one possible implementation, the concentration of the electroplating solution refers to the concentration of copper ions and related additives in the electroplating solution, which can affect the crystal quality and adhesion of the copper layer. If the concentration is too high, it is easy to cause burrs in the copper layer, while if the concentration is too low, the copper plating speed is slow and the copper layer is not dense.

[0083] In one possible implementation, electroplating information can be obtained from a preset design file, and then the circuit board to be processed can be placed in an electroplating tank so that the circuit board is completely immersed in the (copper sulfate) electroplating solution and precisely connected to the motor to avoid poor contact that could lead to uneven copper plating.

[0084] In one possible implementation, during the copper plating process on the surface of the circuit board to be processed, a Copper Thickness Measuring Instrument (CMI) can be used to detect the copper layer thickness at different locations on the surface of the circuit board. The difference between the copper layer thickness at each location and the preset copper layer thickness is controlled within the range of [-3 micrometers (μm) to 3 μm]. Simultaneously, the copper layer surface is checked for burrs, pinholes, and peeling. If the test fails, the copper plating process needs to be repeated; if the test passes, gold plating can continue in the gold finger areas of the circuit board. The preset copper layer thickness is, for example, 25 μm.

[0085] S103. Apply a dry film to the surface of a first region of the circuit board to be processed. The first region includes a circuit region, a gold finger region, and a first temporary lead region. The length of the first temporary lead region is less than or equal to a second threshold.

[0086] In one possible implementation, the dry film is a photosensitive polymer film that is attached to the surface of the circuit board to be processed and can form an etch-resistant protective layer after exposure and development.

[0087] In one possible implementation, the circuit area refers to the copper wire area on the circuit board to be processed used to transmit electrical signals and realize the electrical connection of devices. There are areas without circuits and areas with circuits.

[0088] In one possible implementation, the first temporary lead area refers to a conductive lead temporarily designed to enable normal electroplating of the gold finger, which can be removed by etching after the gold plating is completed.

[0089] In one possible implementation, the second threshold refers to the maximum permissible length of the temporary lead covered by the dry film. The second threshold is, for example, 2 mil.

[0090] For example, taking a first temporary lead region with a length of 1 mil as an example, combined with Figure 3 The length of the first temporary lead area needs to be explained. It should be noted that... Figure 3 This explanation only uses the example of applying dry film to the gold finger area and the first temporary lead area, but not to the circuit area. Figure 3 This is a schematic diagram of a dry film coverage area provided in an embodiment of this application, as shown below. Figure 3As shown, the dry film covers the gold finger area (gold-plated) and the first temporary lead area (copper-plated). The length of the first temporary lead area is 1 mil, while the dry film does not cover the area of ​​the second temporary lead area other than the first temporary lead area. The description of the second temporary lead area can be found in subsequent embodiments and will not be repeated here.

[0091] In this way, by accurately covering the circuit area, the gold finger area, and the first temporary lead area with a length less than or equal to the second threshold, while avoiding the part of the second temporary lead area other than the first temporary lead area, the length of the gold finger suspension can be reduced, the risk of short circuit and metal debris falling off can be reduced, and operation space can be reserved for subsequent etching to remove excess temporary leads, thereby improving the quality of gold finger forming and the stability of high-frequency and high-speed signal transmission.

[0092] In some implementations, before applying a dry film to the surface of the first region of the circuit board to be treated, the surface of the circuit board to be treated can also be washed with water using volcanic ash.

[0093] It should be noted that before applying the dry film to the surface of the first area of ​​the circuit board to be treated, only the surface of the circuit board to be treated is washed with water, and the surface of the circuit board to be treated is not micro-etched or brushed.

[0094] This effectively removes impurities and oxide layers from the surface of the circuit board to be treated, improves the adhesion of the dry film, and avoids micro-etching or brushing damage to the copper layer of the circuit area, gold finger area, and first temporary lead area. It also prevents the copper layer from becoming thinner and burrs from appearing on the edges, avoids brushing from causing scratches in the gold finger area, improves the stability of subsequent gold plating and etching processes, improves the gold finger forming accuracy, and controls the length of the suspended gold.

[0095] In one possible implementation, before washing the surface of the circuit board to be treated with water using volcanic ash, the following may also be done:

[0096] The circuit board to be processed is sandblasted; solder resist ink is printed on the surface of the circuit board to be processed; the circuit board to be processed is then pre-baked, and the circuit area, gold finger area, and second temporary lead area are exposed based on multiple coordinate points of each panel unit; finally, the surface of the circuit board to be processed is developed.

[0097] In one possible implementation, the gold finger circuit board can be placed in a sandblasting equipment for sandblasting, using quartz sand as the sandblasting material. During the sandblasting process, no micro-etching or brushing is performed, thereby removing the copper oxide layer, fingerprints, and minor scratches, so that the copper surface roughness meets the requirements for solder mask, and avoiding copper surface thinning or damage.

[0098] After sandblasting, the corresponding mesh size of the screen is determined according to the preset copper layer thickness for printing solder resist ink, so as to make the solder resist ink coating uniform and avoid clogging, oil accumulation or exposed copper.

[0099] Next, the circuit board to be processed can be placed in an oven or tunnel oven for pre-baking. The pre-baking temperature can be within a preset pre-baking temperature range. By precisely controlling the pre-baking temperature, the solder resist ink can be initially cured, avoiding problems such as ink peeling and bubbling during subsequent exposure and development. For example, the preset pre-baking temperature range is [70℃, 80℃].

[0100] After pre-baking, a laser direct imaging machine can be used to align the components of each panel unit with the cursor points as a reference. Then, the circuit area, the gold finger area, and the second temporary lead area are exposed. When exposing the gold finger area, a preset first expansion amount (e.g., 5 mil) can be added both horizontally and vertically to the gold finger area indicated in the preset design document. When exposing the second temporary lead area, a preset second expansion amount (e.g., 3.5 mil) can be added both horizontally and vertically to the second temporary lead area indicated in the preset design document. By precisely controlling the exposure range and reserving a safety boundary for process deviation, the solderability of the gold fingers and the adhesion between the lead and the solder resist layer are guaranteed.

[0101] After exposure, the surface of the circuit board to be processed can be developed to remove the unexposed solder resist ink and form a solder resist pattern that meets the design requirements.

[0102] S104. Expose the circuit area and gold finger area, and develop the circuit board to be processed.

[0103] In one possible implementation, exposure refers to using a laser direct imaging (LDI) machine to light-cur the dry film based on a preset design pattern, thereby determining the boundaries of the areas to be retained and removed.

[0104] In one possible implementation, development refers to using a developer to dissolve and remove the unexposed dry film, leaving the exposed and cured dry film, thus exposing the copper surface to be etched.

[0105] In one possible implementation, a laser direct imaging machine can be used to align the components of each panel using their respective cursor points as a reference, ensuring an alignment deviation of less than or equal to 50μm. This achieves high-precision alignment and neat edges on the gold fingers. Next, the circuit area and gold finger area are exposed, and then the circuit board to be processed is developed using a developing machine to wash away the unexposed dry film, exposing temporary leads. After exposure, the dry film in the circuit area and gold finger area solidifies, forming a protective layer that resists etching and electroplating.

[0106] S105. Etch the circuit board to be processed to obtain the gold finger circuit board.

[0107] In one possible implementation, etching refers to using an acidic or alkaline etchant to corrode and remove the exposed copper layer that is not protected by the dry film, leaving the copper layer under the dry film intact.

[0108] In some implementations, etching the circuit board to be processed can include:

[0109] Spray an alkaline etching solution onto the surface of the circuit board to be processed; clean the dry film on the surface of the first area.

[0110] In one possible implementation, alkaline etching solution refers to an alkaline chemical etching solution, whose components may include ammonia, copper chloride, etc., and the reaction is mild and highly precise.

[0111] In one possible implementation, the circuit board to be processed can be fed into an etching machine, where an alkaline etching solution is sprayed evenly to remove the copper layer in areas without dry film coverage; then, the dry film on the surface of the first area is removed by an alkaline stripping solution, followed by washing and drying.

[0112] It should be noted that no tin stripping is performed before or after spraying alkaline etching solution on the surface of the circuit board to be treated and before cleaning the dry film on the surface of the first area. This can avoid the tin stripping process causing corrosion or damage to the surface of the circuit board to be treated.

[0113] In this way, by spraying alkaline etching solution onto the surface of the circuit board to be processed, excess copper layer in areas without dry film coverage can be accurately removed, avoiding damage to the circuit areas, gold finger areas, and first temporary lead areas protected by the dry film. This ensures that the patterns in each conductive area are complete, the edges are neat, and there is no residual copper or side etching, thus guaranteeing the forming accuracy of the circuit and gold finger. Then, by removing the dry film on the surface of the first area with alkaline stripping solution and washing and drying with water, it is possible to avoid residual dry film affecting the stability of subsequent processes. It can also fully expose the circuit, gold finger, and the controlled length of suspended gold, thereby improving the electrical connection reliability of the gold finger circuit board and the stability of high-frequency and high-speed data transmission.

[0114] In this embodiment, a circuit board to be processed is obtained; copper is plated on the surface of the circuit board to be processed, and gold is plated in the gold finger area of ​​the circuit board to be processed, the length of the gold finger area being greater than or equal to a first threshold; a dry film is attached to the surface of a first area of ​​the circuit board to be processed, the first area including a circuit area, a gold finger area and a first temporary lead area, the length of the first temporary lead area being less than or equal to a second threshold; the circuit area and the gold finger area are exposed, and the circuit board to be processed is developed; the circuit board to be processed is etched to obtain a gold finger circuit board.

[0115] In the above method, by controlling the length of the gold finger area and the length of the first temporary lead area covered by the dry film before etching the circuit board to be processed, the problems of gold layer overflow and excessive gold suspension during the gold plating process can be avoided. Reducing the length of the gold suspension on the gold finger reduces the risk of metal debris falling off and contact short circuit, improves the signal crosstalk suppression capability, and improves the stability and speed of high-frequency and high-speed data transmission. In addition, it can also extend the service life of the gold finger circuit board.

[0116] Based on the above embodiments, after etching the circuit board to be processed to obtain the gold finger circuit board, it is also possible to:

[0117] The gold finger circuit board is sandblasted; green oil is applied to the surface of the gold finger circuit board; the third area of ​​the gold finger circuit board is exposed and developed. The third area includes the area outside the lines in the gold finger area and the circuit area of ​​the circuit board to be gold fingered.

[0118] In one possible implementation, sandblasting involves using a high-pressure airflow to spray quartz sand onto the surface of the gold finger circuit board, removing the surface oxide layer, impurities, and residual chemicals, making the surface of the gold finger circuit board smoother and preparing it for subsequent application of green oil.

[0119] In one possible implementation, applying green oil to the surface of the gold finger circuit board refers to using liquid green oil to evenly coat the surface of the gold finger circuit board, forming a protective film for preventing oxidation and corrosion.

[0120] In one possible implementation, the gold finger circuit board can be placed in a sandblasting device for sandblasting, using quartz sand as the sandblasting material; after sandblasting, the gold finger circuit board can be placed in a green oil coating device, using liquid green oil to evenly coat the surface of the gold finger circuit board; then, the third area of ​​the gold finger circuit board can be exposed using an LDI machine; after exposure, the surface of the gold finger circuit board can be developed.

[0121] In this way, sandblasting the etched gold finger circuit board removes the surface oxide layer, impurities, and residual chemicals, making the surface smoother and providing a clean and highly adhesive surface for subsequent solder mask application, preventing issues such as solder mask peeling and bubbles. Then, a uniform coating of liquid solder mask forms a reliable protective film on the surface of the gold finger circuit board, isolating it from external factors such as air and moisture, protecting the conductivity of the circuit and gold finger areas from damage. Subsequent exposure and development processes preserve the conductive patterns of the gold finger and circuit areas while removing excess solder mask from the third area. This improves the structural stability, electrical connection reliability, and lifespan of the gold finger circuit board, meeting the requirements of high-frequency, high-speed signal transmission and long-term plugging and unplugging applications.

[0122] Next, combined Figure 4 This paper provides a detailed description of a method for gold plating in the gold finger area of ​​a circuit board to be processed, exemplarily. Figure 4 This is a flowchart illustrating a method for gold plating in a gold finger area, provided as an embodiment of this application. Please refer to... Figure 4 As shown, the method may include the following steps:

[0123] S401. Based on multiple cursor points of each panel unit, the circuit board to be processed is sequentially subjected to roughening treatment, wet film printing treatment, and dry film printing gold plating treatment.

[0124] In one possible implementation, roughening is achieved by chemically roughening the surface of the circuit board to be treated. The wet film printing process involves applying a liquid photosensitive wet film to the surface of the circuit board using screen printing. After pre-baking, exposure, and development, a masking layer is formed. The dry film printing process involves applying a dry gold-plated film to the surface of the circuit board to be treated. After exposure and development, only the gold finger area is exposed.

[0125] In some implementations, the circuit board to be processed is coarsened based on multiple cursor points in each panel unit, which may include:

[0126] The surface of the circuit board to be processed is polished; the surface of the circuit board to be processed is roughened; a dry film is applied to the surface of the circuit board to be processed, and the surface of the circuit board to be processed is subjected to air pressure treatment; the second area of ​​the circuit board to be processed is exposed based on multiple cursor points of each panel unit; the surface of the circuit board to be processed is developed and acid etched.

[0127] Among them, polishing is used to clean and level the surface of the circuit board to be treated; roughening is used to increase the surface roughness of the circuit board to be treated; air pressure treatment is used to strengthen the adhesion between the dry film and the surface of the circuit board to be treated; the second region includes the gold finger region, the second temporary lead region and each line in the line region, and the second temporary lead region includes the first temporary lead region.

[0128] In one possible implementation, polishing involves using a fine ceramic brush to physically grind the surface of the circuit board to be treated, removing oxidation, impurities, and burrs to make the surface smooth and clean. Air pressure treatment involves applying uniform pressure to the surface of the circuit board to be treated using air pressure to expel air from under the film, allowing the dry film to adhere tightly to the copper surface.

[0129] In one possible implementation, the second temporary lead region is a temporary auxiliary conductive path set up to achieve conductive electroplating of the gold finger, including the first temporary lead region, which can be removed by alkaline etching after gold plating is completed.

[0130] In one possible implementation, the surface of the circuit board to be processed can be polished using a 2000-mesh ceramic brush. During the polishing process, the working current of the 2000-mesh ceramic brush is within a preset current range, the polishing speed is a preset speed, and the gold finger area can be focused on for inspection to ensure that the gold finger area is free of abrasion marks and scratches, thereby improving the flatness and appearance quality of the gold finger surface. The preset current range is [1 Ampere (A), 2A], and the preset speed is 2 meters per minute (m / min).

[0131] In one possible implementation, after polishing, the surface of the circuit board to be treated can be subjected to ultra-roughening treatment to create a micro-uneven structure on the copper surface. This improves the adhesion between the dry film and the copper surface, preventing problems such as film bubbles, edge lifting, and chemical seepage. During the roughening process, the abrasive brush is not turned on to avoid damaging the edges of the copper surface and the gold fingers.

[0132] In one possible implementation, a dry film can be applied to the surface of the circuit board to be processed using a hot press roller, ensuring uniform adhesion. During the application process, the roller temperature remains within a preset range, and the roller pressure is also a preset value. The preset temperature range is [100℃, 120℃], and the preset pressure is 5 kg / cm². 2 .

[0133] In one possible implementation, pneumatic compression can be performed immediately after the dry film is applied to remove the air beneath the dry film, ensuring complete adhesion between the dry film and the copper surface without gaps or air bubbles.

[0134] In one possible implementation, a laser direct imaging machine can be used to align the components of each panel unit with reference points, ensuring that the alignment deviation is less than or equal to 50 μm. Then, the second area is exposed. After the second area is exposed, the surface of the circuit board to be processed is developed to wash away the unexposed dry film. Subsequently, acid etching is performed by spraying acidic etching solution to remove the exposed copper layer, while retaining the circuit, gold fingers, and second temporary leads protected by the dry film, thus completing the outer layer pattern formation.

[0135] In this way, the circuit board can be polished, roughened, dry film applied, air-pressed, exposed, developed, and acid-etched sequentially using the cursor points of each panel unit as a reference. Polishing with a 2000-grit ceramic brush effectively removes oxidation and burrs while ensuring that the gold fingers are scratch-free. The roughening process without abrasion creates a micro-concave-convex structure to improve the adhesion of the dry film. Combined with hot-pressing film application and air-pressing, air bubbles are eliminated and dry film lifting and chemical seepage are prevented. The cursor point reference is then used for alignment to improve the pattern accuracy. Finally, development and acid etching accurately preserve the circuitry, gold fingers, and second temporary leads in the second area. This can improve the forming accuracy, surface flatness, and appearance quality of the outer layer circuitry and gold fingers, as well as the reliability of the temporary leads' conductivity, while protecting the copper surface and the edges of the gold fingers from damage.

[0136] In some implementations, wet film printing is performed on the circuit board to be processed based on multiple cursor points in each panel unit, which may include:

[0137] A wet film is applied to the surface of the circuit board to be processed; the circuit area and the second temporary lead area are exposed based on multiple cursor points of each panel unit; and the surface of the circuit board to be processed is developed.

[0138] In one possible implementation, a wet film can be applied to the surface of the circuit board to be processed using a 51T screen printing plate. After the wet film is applied, the surface of the circuit board is pre-baked to allow the wet film to initially cure. The thickness of the applied wet film is within a preset thickness range, the pre-baking temperature is a preset pre-baking temperature, and the pre-baking time is a preset pre-baking time. The preset thickness range is, for example, [20μm, 30μm], the preset pre-baking temperature is, for example, 75℃, and the preset pre-baking time is, for example, 45 minutes.

[0139] In one possible implementation, after pre-baking, the circuit board to be processed is left to stand for a preset time (e.g., 15 minutes), and then aligned using a laser direct imaging machine with each cursor point of each panel unit as a reference, so that the alignment deviation is less than or equal to 25μm; then the circuit area and the second temporary lead area are exposed; after the circuit area and the second temporary lead area are exposed, the surface of the circuit board to be processed is developed, exposing only the gold finger area, while the circuit area and the second temporary lead area are protected by a wet film.

[0140] It should be noted that a wet film can be applied to the surface of the circuit board to be processed based on a preset design file.

[0141] In this way, a uniformly thick wet film can be printed using a 51T screen printing plate. Then, high-precision alignment can be performed using the cursor points of each panel unit as a reference. The circuit area and the second temporary lead area are exposed, leaving only the gold finger area exposed. This not only provides complete and uniform anti-etch protection for the circuit area and the second temporary lead area using the wet film, ensuring pattern accuracy and conductivity stability, but also accurately exposes the gold finger area to prepare for the subsequent gold plating process. At the same time, by controlling the wet film thickness, pre-baking parameters, and alignment accuracy, problems such as wet film peeling, alignment misalignment, and uneven development can be avoided, improving the boundary clarity between the gold finger area and the circuit area, and further improving the gold finger forming quality, gold plating control accuracy, and overall electrical performance reliability.

[0142] In some implementations, based on multiple cursor points in each panel unit, the printed gold-plated dry film processing of the circuit board to be processed can include:

[0143] A gold-plated dry film is applied to the surface of the circuit board to be processed; the gold finger area is exposed based on multiple cursor points of each panel unit; and the surface of the circuit board to be processed is developed.

[0144] In one possible implementation, the gold-plated dry film is resistant to corrosion from the gold plating solution and has strong shielding properties. For example, the gold-plated dry film is the GPM-220 type.

[0145] In one possible implementation, after the gold-plated dry film is applied to the surface of the circuit board to be processed, alignment can be performed using a laser direct imaging machine with each cursor point of each panel unit as a reference, so that the alignment deviation is less than or equal to 50μm; then the gold finger area is exposed; after the gold finger area is exposed, the surface of the circuit board to be processed is developed. After development, the gold plating layer of the gold finger area is exposed, and the required gold finger structure can be formed. The circuit area and the second temporary lead area are covered by the gold-plated dry film.

[0146] In this way, a gold-plated dry film that is resistant to gold plating solution corrosion and has strong shielding properties can be applied to the surface of the circuit board to be processed. The alignment is controlled by using the cursor points of each panel unit as a reference, thereby improving the accuracy of exposure. Then, the gold finger area is accurately exposed, exposing the gold plating layer in the gold finger area to form the required gold finger structure. At the same time, the gold-plated dry film covers and protects the circuit area and the second temporary lead area, which can prevent the gold plating solution from corroding the circuit area and the second temporary lead, ensuring their structural integrity and conductivity reliability. It can also accurately define the scope of gold plating, prevent gold layer overflow, improve the accuracy of gold finger forming, improve the electrical connection stability and service life of the circuit board to be processed, and meet the requirements of high-frequency, high-speed data transmission and long-term plugging and unplugging scenarios.

[0147] S402. A nickel layer and a gold layer are sequentially plated in the gold finger area, and the gold-plated dry film on the surface of the circuit board to be treated is cleaned.

[0148] In one possible implementation, the nickel plating layer refers to electroplating a layer of metallic nickel between the copper surface and the gold layer, serving as a barrier layer and a transition layer, while the gold plating layer refers to electroplating pure gold on the surface of the nickel layer, serving as the final contact interface.

[0149] In one possible implementation, cleaning the gold-plated dry film on the surface of the circuit board to be processed means using a stripping solution to remove the residual gold-plated dry film after gold plating, so that the surface of the circuit board to be processed is clean and ready for subsequent processes.

[0150] In one possible implementation, current can be conducted through temporary leads, and a nickel layer can be plated only on the copper surface of the exposed gold finger area to improve the adhesion of the gold layer; then, a gold layer can be electroplated on the nickel layer surface to form a wear-resistant, oxidation-resistant, and low-resistance contact interface. The thickness of the nickel layer can be within a preset nickel layer thickness range, and the thickness of the gold layer can be within a preset gold layer thickness range. For example, the preset nickel layer thickness range is [1.2μm, 1.5μm], and the preset gold layer thickness range is [0.05μm, 0.08μm].

[0151] In one possible implementation, after plating nickel and gold layers in the gold finger area, a stripping solution can be used to clean the dry gold plating film on the surface of the circuit board to be treated, thereby removing the residual dry gold plating film in the circuit area and the second temporary lead area, leaving the surface clean, without residual film or chemical residue.

[0152] In this embodiment, based on multiple cursor points of each panel unit, the circuit board to be processed is sequentially roughened, wet film printed, and dry film printed with gold plating. Nickel and gold layers are sequentially plated in the gold finger area, and the dry film of gold plating on the surface of the circuit board to be processed is cleaned.

[0153] In the above method, by combining the alignment of multiple cursor points of each panel unit, the precise positioning of roughening treatment, wet film printing, dry gold plating printing, and subsequent gold plating processes is ensured, alignment deviation is controlled, and the accuracy of the graphics in each process is improved. By plating nickel and gold layers in the gold finger area, the nickel layer is used as a transition barrier layer to improve the adhesion of the gold layer. The gold layer forms a wear-resistant and oxidation-resistant contact interface. Finally, the residual dry gold plating film is cleaned to ensure that the surface of the circuit board to be processed is clean and free of residue. This method can accurately control the precision of gold finger forming and the length of gold suspension, avoid gold layer overflow, plating seepage, and circuit corrosion, and also improve the conductivity, wear resistance, and service life of the gold fingers. This improves the product yield and electrical performance of the gold finger circuit board, meeting the requirements of high-frequency, high-speed data transmission and long-term plugging and unplugging scenarios.

[0154] This application also provides a gold finger circuit board, which is obtained by the gold finger circuit board manufacturing method described in any of the preceding claims.

[0155] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A method for manufacturing a gold finger circuit board, characterized in that, include: Obtain the circuit board to be processed; Copper is plated on the surface of the circuit board to be processed, and gold is plated in the gold finger area of ​​the circuit board to be processed, wherein the length of the gold finger area is greater than or equal to a first threshold. A dry film is applied to the surface of a first region of the circuit board to be processed. The first region includes a circuit region, the gold finger region, and a first temporary lead region. The length of the first temporary lead region is less than or equal to a second threshold. The circuit area and the gold finger area are exposed, and the circuit board to be processed is developed. The circuit board to be processed is etched to obtain a gold finger circuit board.

2. The method according to claim 1, characterized in that, The circuit board to be processed includes multiple panel units, each panel unit including multiple preset cursor points, the multiple cursor points being used to locate and mark each panel unit, and the gold plating of the gold finger area in the circuit board to be processed includes: Based on multiple cursor points of each panel unit, the circuit board to be processed is sequentially subjected to roughening treatment, wet film printing treatment, and dry film printing gold plating treatment. Nickel and gold layers are plated sequentially in the gold finger area, and the gold-plated dry film on the surface of the circuit board to be treated is cleaned.

3. The method according to claim 2, characterized in that, Based on multiple cursor points of each panel unit, the circuit board to be processed is coarsened, including: The surface of the circuit board to be processed is polished, and the polishing process is used to clean and smooth the surface of the circuit board to be processed. The surface of the circuit board to be processed is roughened to increase the surface roughness of the circuit board. A dry film is applied to the surface of the circuit board to be processed, and the surface of the circuit board to be processed is subjected to air pressure treatment. The air pressure treatment is used to enhance the adhesion between the dry film and the surface of the circuit board to be processed. Based on multiple cursor points of each panel unit, the second area of ​​the circuit board to be processed is exposed. The second area includes the gold finger area, the second temporary lead area and each line in the line area. The second temporary lead area includes the first temporary lead area. The surface of the circuit board to be processed is developed and acid-etched.

4. The method according to claim 3, characterized in that, The step of performing wet film printing on the circuit board to be processed based on multiple cursor points of each panel unit includes: A wet film is applied to the surface of the circuit board to be processed; Based on multiple cursor points of each panel unit, the line area and the second temporary lead area are exposed; The surface of the circuit board to be processed is developed.

5. The method according to claim 2, characterized in that, The step of performing a printed gold plating dry film treatment on the circuit board to be processed based on multiple cursor points of each panel unit includes: A gold-plated dry film is applied to the surface of the circuit board to be processed; The gold finger area is exposed based on multiple cursor points of each panel unit; The surface of the circuit board to be processed is developed.

6. The method according to claim 1, characterized in that, The copper plating process on the surface of the circuit board to be processed includes: Obtain electroplating information, which includes one or more of the following: electroplating current, electroplating duration, electroplating temperature, and electroplating solution concentration; Based on the electroplating information, copper is plated on the surface of the circuit board to be processed.

7. The method according to claim 1, characterized in that, The etching of the circuit board to be processed includes: An alkaline etching solution is sprayed onto the surface of the circuit board to be processed. The dry film on the surface of the first region is cleaned.

8. The method according to claim 1, characterized in that, Before applying a dry film to the surface of the first region of the circuit board to be processed, the method further includes: The surface of the circuit board to be treated is washed with water using volcanic ash.

9. The method according to claim 1, characterized in that, After etching the circuit board to be processed to obtain the gold finger circuit board, the method further includes: The gold finger circuit board is sandblasted. Green oil is applied to the surface of the gold finger circuit board; The third region of the gold finger circuit board is exposed and developed. The third region includes the area outside the gold finger region and the circuit region of the gold finger circuit board.

10. A gold finger circuit board, characterized in that, The gold finger circuit board is formed based on the manufacturing method of the gold finger circuit board according to any one of claims 1 to 9.

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