A manufacturing method of a gold-plated circuit board

Abstract

The present invention discloses a method for manufacturing a gold-plated circuit board, comprising: providing a substrate, wherein the substrate includes a central region and an edge region, a plurality of gold-plated connection pads arranged in an array are provided in the central region, the plurality of gold-plated connection pads arranged in the array are connected in series with each other through leads, at least one gold-plating auxiliary connection pad is provided in the edge region, and the gold-plating auxiliary connection pad is connected in series with the gold-plated connection pads in the central region through leads; providing a gold-plating barrier film on the surface of the substrate, the gold-plating barrier film covering non-gold-plated regions other than the gold-plated connection pads and the gold-plating auxiliary connection pads; performing gold plating on the gold-plated connection pads and the gold-plating auxiliary connection pads; removing the gold-plating barrier film and the leads in the central region; and removing the edge region. The present invention can avoid the gold-plated connection pads from being charred by the initial current.

Description

Technical Field

[0001] The present invention relates to the technical field of circuit boards, and particularly to a method for manufacturing a gold-plated circuit board. Background Art

[0002] A gold finger board is a type of PCB gold-plated board. Its main function is to achieve flexible interconnection with the main board PCB, ensuring the performance requirements while facilitating disassembly and replacement. The implementation method is to design a row of gold finger connection pads on the gold finger board, and at the same time, coat a layer of thick gold on the surface of the connection pads to enhance the wear resistance and conductivity of the connection pad surface. The connection pad after gold plating is usually called a gold finger.

[0003] There is a new type of PCB gold-plated board, mainly used for chip testing. Its characteristic is that it requires high-density matrix connection pad gold plating, and it serves as one of the bridges for communicating between the chip and the PCB main board. The main difference between this type of high-density matrix gold-plated chip test board and the traditional plug gold-plated board lies in the different numbers of gold-plated connection pads. The traditional plug gold-plated board is only used for component signal transmission, and the number of signals to be transmitted is small, so only a row of gold fingers needs to be designed. Because there is enough space, gold plating is easy to achieve. As the chip test transmission path, the high-density matrix gold-plated chip test board has many docking channels, and multiple rows of high-density matrix connection pads need to be designed to transmit more independent signals for the chip.

[0004] Because the total area of the high-density matrix connection pads that need to be gold-plated is relatively larger than the total area of the gold-plated traditional plug gold-plated board, a larger current is required during the gold plating process. And the area of a single gold-plated connection pad of the high-density matrix connection pad is relatively smaller than that of the traditional plug gold-plated connection pad. Considering the above two factors, during the gold plating of the high-density matrix connection pads, it is easier to have the problem of burning at the lead connection end and the starting point of the high-density matrix connection pad network. Summary of the Invention

[0005] The present invention provides a method for manufacturing a gold-plated circuit board to avoid the initial current from burning the connection pads to be gold-plated.

[0006] According to one aspect of the present invention, there is provided a method for manufacturing a gold-plated circuit board, including:

[0007] Providing a substrate, wherein the substrate includes a central area and an edge area. The central area is provided with a plurality of connection pads to be gold-plated arranged in an array, and the plurality of connection pads to be gold-plated arranged in an array are connected in series with each other through leads. The edge area is provided with at least one gold-plating auxiliary connection pad, and the gold-plating auxiliary connection pad is connected in series with the connection pads to be gold-plated in the central area through a lead;

[0008] Providing a gold-plating barrier film on the surface of the substrate, and the gold-plating barrier film covers the non-gold-plated areas except the connection pads to be gold-plated and the gold-plating auxiliary connection pads;

[0009] Gold plate the to-be-gold-plated connection pad and the gold-plating auxiliary connection pad;

[0010] Remove the gold-plating barrier film and the lead in the central region;

[0011] Remove the edge region.

[0012] Optionally, at least two gold-plating auxiliary connection pads are provided in the edge region, and the ratio of the width of the gold-plating auxiliary connection pad to the width of the to-be-gold-plated connection pad is greater than or equal to 2, and the ratio of the length of the gold-plating auxiliary connection pad to the length of the to-be-gold-plated connection pad is greater than or equal to 5.

[0013] Optionally, the lead includes a first lead segment and a second lead segment. The first lead segment is adjacent to the to-be-gold-plated connection pad, and each edge of the to-be-gold-plated connection pad connected to the lead is connected to the second lead segment through the first lead segment;

[0014] The line width of the first lead segment is less than the line width of the second lead segment, and the length of the first lead segment is greater than or equal to a first set value.

[0015] Optionally, the difference between the line width of the second lead segment and the line width of the first lead segment is 1 mil, the first set value is 2 mil, the line width of the lead in the edge region is greater than the line width of the second lead segment, and the difference between the line width of the lead in the edge region and the line width of the second lead segment is greater than or equal to 2 mil.

[0016] Optionally, a gold-plating barrier film is provided on the surface of the substrate, and the gold-plating covering film covers the non-gold-plated areas except the to-be-gold-plated connection pad and the gold-plating auxiliary connection pad, including:

[0017] Provide a partial gold-plating barrier film on the surface of the substrate; wherein,

[0018] The local gold plating barrier film covers a partial area of each of the first lead segments and other leads outside the first lead segments; the local gold plating barrier film includes a first barrier area and a second barrier area. A corresponding first barrier area is provided for each of the first lead segments. The first barrier area covers a partial area of the first lead segment and at least a partial second lead segment adjacent to the first lead segment, and the second barrier area covers the second lead segments not covered by the first barrier area; the first barrier area includes a first boundary adjacent to the gold plating connection pad to be plated and a second boundary parallel to the extending direction of the second lead segment. The distance between the first boundary and the boundary of the first lead segment adjacent to the gold plating connection pad to be plated is greater than or equal to a second set value, and the distance between the first boundary and the boundary of the first lead segment away from the gold plating pad to be plated is greater than or equal to the second set value. The first boundary includes a first straight segment and second straight segments located on both sides of the first straight segment. The second straight segments are inclined away from the gold plating connection pad relative to the first straight segment, and the included angle between the second straight segments and the boundary of the gold plating connection pad is greater than or equal to a preset angle. The distance between the second boundary and the second lead segment is greater than or equal to a third set value;

[0019] An anti-gold plating tape is provided on the surface of the substrate, and the anti-gold plating tape covers other non-gold plating areas.

[0020] Optionally, the second set value is 1 mil, the preset angle is 30 degrees, and the third set value is 4 mil.

[0021] Optionally, the local gold plating barrier film is a wet film or a first dry film;

[0022] When the local gold plating barrier film is a first dry film, after the local gold plating barrier film is provided on the surface of the substrate, it further includes: performing low-temperature baking on the first dry film.

[0023] Optionally, providing the local gold plating barrier film on the surface of the substrate includes:

[0024] Forming a gold plating barrier material layer on the surface of the substrate;

[0025] Performing an exposure process on the gold plating barrier material layer so that the gold plating barrier material layer to be retained is photocured;

[0026] Developing the exposed gold plating barrier material layer to remove the gold plating barrier material layer not photocured, thereby forming the local gold plating barrier film.

[0027] Optionally, before removing the gold plating barrier film and the leads in the central area, it further includes:

[0028] Fabricate a solder mask, where the solder mask covers areas other than the leads and the pads to be gold-plated after gold plating.

[0029] Removing the gold plating barrier film and the leads in the central region includes:

[0030] Dispose a second dry film on the side of the solder mask away from the substrate, where the second dry film covers areas other than the leads.

[0031] Etch the leads.

[0032] Remove the second dry film.

[0033] Optionally, disposing a second dry film on the side of the solder mask away from the substrate, where the second dry film covers areas other than the leads, includes:

[0034] Dispose a dry film on the side of the solder mask away from the substrate.

[0035] Expose the dry film so that the dry film to be retained is photocured.

[0036] Develop the exposed dry film to remove the dry film that has not been photocured, forming the second dry film.

[0037] In the embodiment of the present invention, by providing gold plating auxiliary pads in the edge region of the substrate, and the gold plating auxiliary pads are connected in series with the pads to be gold-plated in the central region, such that during gold plating, the gold plating auxiliary pads are located at the starting position of gold plating, and the pads at the starting position of gold plating are prone to be charred by the initial current during gold plating. By providing the gold plating auxiliary pads, it is possible to prevent the pads to be gold-plated in the central region from being charred by the initial current.

[0038] It should be understood that the content described in this part is not intended to identify the key or important features of the embodiments of the present invention, nor is it used to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] To more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following-described drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0040] Figure 1 is a flowchart of a method for fabricating a gold-plated circuit board provided in Embodiment 1 of the present invention;

[0041] Figure 2 is a schematic diagram of a gold-plated circuit board provided in Embodiment 1 of the present invention;

[0042] Figure 3 It is a partial enlarged view of a gold-plated circuit board provided by an embodiment of the present invention;

[0043] Figure 4 It is a schematic diagram of another gold-plated circuit board provided by an embodiment of the present invention;

[0044] Figure 5 It is a partial enlarged view of another gold-plated circuit board provided by an embodiment of the present invention;

[0045] Figure 6 It is a flowchart of a manufacturing method of a gold-plated circuit board provided by Embodiment 2 of the present invention. Detailed implementation manners

[0046] In order to enable those skilled in the art to better understand the solution of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0047] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily need to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device comprising a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0048] Embodiment 1

[0049] Figure 1 It is a flowchart of a manufacturing method of a gold-plated circuit board provided by Embodiment 1 of the present invention, Figure 2 It is a schematic diagram of a gold-plated circuit board provided by Embodiment 1 of the present invention. Refer to Figure 1 Figure 2 , and the manufacturing method of the gold-plated circuit board includes:

[0050] S110. Provide a substrate, wherein the substrate includes a central region and an edge region. The central region is provided with a plurality of gold-plating target connection pads arranged in an array, and the plurality of gold-plating target connection pads arranged in an array are connected in series with each other through leads. The edge region is provided with at least one gold-plating auxiliary connection pad, and the gold-plating auxiliary connection pad is connected in series with the gold-plating target connection pads in the central region through a lead.

[0051] Reference Figure 2 , the edge region 12 of the substrate 10 can be located on at least one side of the central region 11. An exemplary edge region 12 can surround the central region 10. The central region 11 is used to set the gold-plating target pads 20 of the gold-plated circuit board, and the edge region 12 is used to set the devices for assisting in manufacturing the central region 11. After the gold-plated circuit board is manufactured, the edge region 12 can be removed. The central region 11 is provided with a plurality of gold-plating target connection pads 20 arranged in an array, that is, the central region 11 is provided with multiple rows of gold-plating target connection pads 20, and each row includes a plurality of gold-plating target connection pads 20. The shape of the gold-plating target connection pad 20 can be a polygon or a polygon with chamfers. Exemplarily, it can be a rectangle. Figure 2 The shape of the gold-plating target connection pad 20 is exemplarily shown, which is not a limitation to the present invention. The gold-plating target connection pads 20 in this embodiment are gold-plating target connection pads 20 arranged in a high-density matrix, that is, high-density matrix connection pads. The distance between adjacent gold-plating connection pads 20 can be set as required, and this embodiment does not make a specific limitation. Exemplarily, it can be set to be greater than or equal to 7 mil.

[0052] The gold-plating target connection pad 20 is the connection pad 20 that needs to be gold-plated. After the gold-plating target connection pad 20 is gold-plated, it becomes a gold finger. The gold-plating auxiliary connection pad 40 will also be gold-plated when the gold-plating target connection pad 20 is gold-plated. It is arranged in the edge region 12 and is connected in series with the gold-plating target connection pad 20. During gold-plating, it is located at the starting position of gold-plating, and the connection pad at the gold-plating starting position is easily burned by the initial current during gold-plating. By setting the gold-plating auxiliary connection pad 40, the gold-plating target connection pads 20 in the central region 11 can be prevented from being burned by the initial current.

[0053] S120. Set a gold-plating barrier film on the surface of the substrate, and the gold-plating barrier film covers the non-gold-plating regions except the gold-plating target connection pads and the gold-plating auxiliary connection pads.

[0054] Specifically, the gold plating barrier film is used to protect the non-gold-plated areas and prevent them from being gold-plated. The non-gold-plated areas may include most of the areas except the pads 20 to be gold-plated and the auxiliary gold-plated pads 40. The non-gold-plated areas include the areas except the pads 20 to be gold-plated, the auxiliary gold-plated pads 40, and the partial areas adjacent to the pads 20 to be gold-plated. The partial areas adjacent to the pads 20 to be gold-plated and the auxiliary gold-plated pads 40 are not provided with the gold plating barrier film in order to enable the pads 20 to be gold-plated sufficiently and avoid the situation that partial edge areas of the pads 20 to be gold-plated cannot be gold-plated due to the coverage of the gold plating barrier film.

[0055] S130. Gold-plate the pads to be gold-plated and the auxiliary gold-plated pads.

[0056] Specifically, when gold-plating, an electric current is passed through the pads to be gold-plated and the auxiliary gold-plated pads connected in series in sequence. Gold ions will deposit on the surfaces of the energized pads to be gold-plated and the auxiliary gold-plated pads, forming a gold plating layer to complete the gold plating.

[0057] S140. Remove the gold plating barrier film and the leads in the central area.

[0058] Among them, both the gold plating barrier film and the leads are used to assist in gold-plating. After the gold plating is completed, the leads can be removed through processes such as etching, and the gold plating barrier film can also be removed through processes such as etching. The removal process of the gold plating barrier film is not specifically limited in this embodiment and can be determined according to the material of the gold plating barrier film.

[0059] S150. Remove the edge area.

[0060] Specifically, the edge area can be cut off through a cutting process or the like to complete the production of the gold-plated circuit board. In addition, before removing the edge area, other film layers such as a solder mask layer can also be set according to the structural requirements of the gold-plated circuit board. The specifically set film layers are not specifically limited in this embodiment.

[0061] In the embodiment of the present invention, by providing auxiliary gold-plated pads in the edge area of the substrate, and connecting the auxiliary gold-plated pads in series with the pads to be gold-plated in the central area, when gold-plating, the auxiliary gold-plated pads are located at the starting position of the gold plating, and the pads at the starting position of the gold plating are easily burned by the initial current during gold-plating. By providing the auxiliary gold-plated pads, the pads to be gold-plated in the central area can be prevented from being burned by the initial current.

[0062] Optionally, at least two auxiliary gold-plated pads 40 are provided in the edge area 12. The ratio of the width M1 of the auxiliary gold-plated pad 40 to the width M2 of the pad 20 to be gold-plated is greater than or equal to 2, and the ratio of the length L1 of the auxiliary gold-plated pad 40 to the length L2 of the pad 20 to be gold-plated is greater than or equal to 5.

[0063] Specifically, the connection pads 20 to be gold-plated in this embodiment are connection pads 20 arranged in a high-density matrix, that is, high-density matrix connection pads. The gold-plating area is 10 to 20 times larger than the area of a conventional gold-plated finger. Under the same gold thickness requirement, the gold-plating current for the high-density matrix connection pads is 10 to 20 times larger. A larger current is more likely to burn the connection pads 20 to be gold-plated. The larger the size of the gold-plating auxiliary connection pads 40, the stronger their ability to withstand the initial current and the stronger their protection ability for the connection pads 20 to be gold-plated in the central region 11. Set the ratio of the width M1 of the gold-plating auxiliary connection pads 40 to the width M2 of the connection pads 20 to be gold-plated to be greater than or equal to 2, and the ratio of the length L1 of the gold-plating auxiliary connection pads 40 to the length L2 of the connection pads 20 to be gold-plated to be greater than or equal to 5, so that the gold-plating auxiliary connection pads 40 can better prevent the connection pads 20 to be gold-plated in the central region 11 from being burned by the initial current.

[0064] Figure 3 is a partial enlarged view of a gold-plated circuit board provided by an embodiment of the present invention. Figure 4 is a schematic diagram of another gold-plated circuit board provided by an embodiment of the present invention. Optionally, refer to Figure 3 and Figure 4 The lead includes a first lead segment 31 and a second lead segment 32. The first lead segment 31 is adjacent to the connection pad 20 to be gold-plated. Each edge of the connection pad 20 to be gold-plated connected to the lead is connected to the second lead segment 32 through the first lead segment 31.

[0065] The line width s2 of the first lead segment 31 is less than the line width W of the second lead segment 32, and the length s1 of the first lead segment 31 is greater than or equal to a first set value.

[0066] Among them, the line width W of the second lead segment 32 can be determined according to the etching process accuracy, etc. This embodiment does not specifically limit the line width W of the second lead segment 32.

[0067] Specifically, in order to ensure good gold plating at the edge of the connection pad 20 to be gold-plated, there is generally a certain distance between the edge of the gold-plating barrier film and the edge of the connection pad 20 to be gold-plated. Figure 4 Exemplarily shows a part of the gold-plating barrier film, that is, Figure 4 the partial gold-plating barrier film 50 in. The lead adjacent to the connection pad 20 to be gold-plated will expose a part of the area. This part of the lead will also be gold-plated when the connection pad 20 to be gold-plated is gold-plated. Therefore, when the lead is finally removed, this part of the gold-plated lead will not be removed. By setting the line width of the first lead segment 31 connected to the connection pad 20 to be gold-plated to be less than the line width of the second lead segment 32, there are fewer remaining leads after the final production of the gold-plated circuit board.

[0068] Optionally, the difference between the line width W of the second lead segment 32 and the line width s2 of the first lead segment 31 is 1 mil, the first set value is 2 mil, the line width of the lead 30 in the edge area 12 is greater than the line width W of the second lead segment 32, and the difference between the line width of the lead 30 in the edge area 12 and the line width W of the second lead segment 32 is greater than or equal to 2 mil.

[0069] Specifically, the first set value is 2 mil, that is, the length s1 of the first lead segment 31 is greater than or equal to 2 mil. The difference between the line width W of the second lead segment 32 and the line width s2 of the first lead segment 31 is set to be 1 mil, and the length s1 of the first lead segment 31 is greater than or equal to 2 mil, which reduces the manufacturing process difficulty of the lead while ensuring the reduction of lead residue.

[0070] In addition, the lead 30 in the edge area 12 can be connected to the electroplating device. By setting the difference between the line width of the lead 30 in the edge area 12 and the line width W of the second lead segment 32 to be greater than or equal to 2 mil, and setting a relatively large gold-plated auxiliary connection pad 40 in the edge area 12, the impact of the initial current can be better alleviated, and the connection pad 20 to be gold-plated can be prevented from being burned by the initial current.

[0071] Optionally, a gold-plating barrier film is provided on the substrate surface, and the gold-plating covering film covers the areas other than the connection pad to be gold-plated and the gold-plated auxiliary connection pad, including:

[0072] A local gold-plating barrier film is provided on the substrate surface; wherein, Figure 5 is a partial enlarged view of another gold-plated circuit board provided by an embodiment of the present invention. Refer to Figure 4 and Figure 5, a partial gold plating barrier film 50 covers a partial area of each first lead segment 31 and other leads outside the first lead segment 31; the partial gold plating barrier film 50 includes a first barrier region 501 and a second barrier region 502. One first barrier region 501 is correspondingly arranged for each first lead segment 31. The first barrier region 501 covers a partial area of the first lead segment 31 and at least a partial second lead segment 32 adjacent to the first lead segment 31. The second barrier region 502 covers the second lead segment 32 not covered by the first barrier region 501; the first barrier region 501 includes a first boundary 51 adjacent to the gold plating connection pad 20 to be plated and a second boundary 52 parallel to the extension direction of the second lead segment 32. The distance d1 between the first boundary 51 and the boundary of the first lead segment adjacent to the gold plating connection pad 20 to be plated and the distance d3 from the boundary far from the gold plating pad 20 are both greater than or equal to a second set value; the first boundary 51 includes a first straight segment 511 and second straight segments 512 located on both sides of the first straight segment 511. The second straight segments 512 are inclined away from the gold plating connection pad 20 relative to the first straight segment 511. The included angle a between the second straight segment 512 and the boundary of the gold plating connection pad 20 is greater than or equal to a preset angle. The distance d2 between the second boundary 52 and the second lead segment 32 is greater than or equal to a third set value;

[0073] An anti-gold plating tape is arranged on the surface of the substrate, and the anti-gold plating tape covers other non-gold plating areas.

[0074] Specifically, the second barrier region 502 of the partial gold plating barrier film 50 covers other leads 30 except the first lead segment 31 and the second lead segment 32 covered by the first barrier region 501. The shape of the first barrier region 501 can be an octagon. The first barrier region 501 is arranged on both sides where each gold plating connection pad 20 is connected to the lead 30. The arrangement of the first barrier region 501 can reduce the residual amount of the lead on the gold plating connection pad 20 caused by manufacturing deviation, and at the same time avoid the peeling and gold seepage of the partial gold plating barrier film 50 on the lead due to the too small area of the partial gold plating barrier film 50 on the lead.

[0075] In addition, for other areas that do not need to be gold plated except the leads, an anti-gold plating tape is pasted to avoid gold plating in the areas that do not need to be gold plated. The anti-gold plating tape has a low price, and the areas that do not need to be gold plated except the leads are large. Using the anti-gold plating tape to block gold plating in the areas that do not need to be gold plated except the leads can reduce the process cost.

[0076] Optionally, the second set value is 1 mil, the preset angle a is 30 degrees, and the third set value is 4 mil.

[0077] Exemplarily, when the length of the first lead segment 31 is 2 mil, the distance d1 between the first straight segment 511 of the first boundary 51 and the gold-plated connection pad 20 to be plated is 1 mil, and the distance d3 between the first straight segment 511 and the boundary of the second lead segment 32 is 1 mil. The pitch between adjacent gold-plated connection pads 20 to be plated is greater than or equal to 7 mil, and the length of the second lead segment 32 between adjacent gold-plated connection pads 20 to be plated is greater than or equal to 3 mil.

[0078] Optionally, the local gold-plating barrier film is a wet film or a first dry film;

[0079] When the local gold-plating barrier film is the first dry film, after the local gold-plating barrier film is provided on the substrate surface, it further includes: performing low-temperature baking on the first dry film.

[0080] Specifically, the wet film has good fluidity and good sealing effect on the leads, which can better avoid gold penetration into the leads. Since the fluidity of the dry film is worse than that of the wet film, the sealing effect on the gold-plated leads is worse than that of the wet film, and it is easy to have the problem of gold penetration under the dry film. In this embodiment, by performing low-temperature baking after setting the dry film, the fluidity of the dry film is increased to enhance the bonding effect between the dry film and the leads. Therefore, the first dry film formed in this embodiment can also have a good sealing effect on the leads.

[0081] Optionally, providing the local gold-plating barrier film on the substrate surface includes:

[0082] Forming a gold-plating barrier material layer on the substrate surface;

[0083] Performing exposure treatment on the gold-plating barrier material layer so that the gold-plating barrier material layer to be retained is photocured;

[0084] Developing the exposed gold-plating barrier material layer to remove the gold-plating barrier material layer that is not photocured, thereby forming the local gold-plating barrier film.

[0085] Specifically, the gold-plating barrier material layer can be a wet film or a dry film. Refer to Figure 4 and Figure 5 , taking the local gold-plating barrier film 50 being a wet film as an example to illustrate the manufacturing process: For the area of the gold-plated connection pad 20 to be plated, a wet film with good fluidity and capable of resisting gold plating after photocuring is printed, and the printed wet film completely covers the gold-plated lead 30. Then, wet film exposure is performed: The wet film at the position of the lead 30 is exposed so that the wet film on the lead 30 can be photocured to prevent gold on the lead during gold plating. The exposed wet film pattern is between two densely arranged gold-plated connection pads 20. The wet film includes a first blocking area 501 and a second blocking area 502. The first blocking area 501 is an octagon. Figure 4 The area where the local gold-plating barrier film 50 is located as shown is the photocured area of the wet film. Finally, developing is performed: After the wet film is developed, Figure 4The area where the partial gold plating barrier film 50 is located can retain the photocured wet film, and the wet film at other positions is removed completely by development, forming the partial gold plating barrier film 50.

[0086] Specifically, after gold plating, the gold plating barrier film 50 is removed, that is, the anti-gold plating tape is torn off, and then the photocured wet film is removed completely by soaking in chemical solution.

[0087] Optionally, before removing the gold plating barrier film and the lead in the central area, it further includes:

[0088] Manufacturing a solder mask layer, the solder mask layer covering the area except the lead and the to-be-gold-plated connection pad after gold plating;

[0089] Removing the gold plating barrier film and the lead in the central area includes:

[0090] Setting a second dry film on the side of the solder mask layer away from the substrate, the second dry film covering the area except the lead;

[0091] Etching the lead;

[0092] Removing the second dry film.

[0093] Specifically, the solder mask layer is a protective layer of the gold-plated circuit board, and the solder mask layer can be manufactured according to the conventional solder mask manufacturing method of the PCB. After manufacturing the solder mask layer, a second dry film is set on the surface of the solder mask layer. The second dry film uses a dry film that can resist the lead etching solution. The second dry film is opened to expose the lead. Through the etching solution, the lead without dry film protection can be removed, and other circuits with dry film protection will not be damaged by the etching solution.

[0094] Optionally, setting a second dry film on the side of the solder mask layer away from the substrate, the second dry film covering the area except the lead, includes:

[0095] Setting a dry film on the side of the solder mask layer away from the substrate;

[0096] Exposing the dry film, so that the dry film to be retained is photocured;

[0097] Developing the exposed dry film, removing the dry film that is not photocured, forming the second dry film.

[0098] Specifically, first, a dry film is pasted on the surface of the solder mask layer. The dry film that can resist the etching solution is pasted on both sides of the gold-plated circuit board as a whole. Then, the dry film at the lead position is opened: after pasting the dry film, the dry film at the non-lead position is photocured, and the dry film at the lead position is designed to block light to avoid photocuring of the dry film. After rinsing with the dry film developing solution, the dry film on the lead can be removed completely, and the dry film at the non-lead position remains on the PCB board.

[0099] After the lead etching is completed, remove the dry film: Remove all the dry films cured by light in positions other than the leads using a dry film stripping solution.

[0100] In the embodiment of the present invention, by designing a gold-plated auxiliary connection pad, it is possible to effectively avoid the problem of board burning that is likely to occur in a high-density matrix gold-plated connection pad with a relatively large total gold-plating area and a relatively small single gold-plated connection pad to be gold-plated. By making a segmented design at the connection position between the lead and the gold-plated connection pads arranged in a high-density matrix, the residual amount of the lead on the gold-plated connection pads to be gold-plated can be reduced. Through the design of a local gold-plating barrier film on the lead, the residual amount of the lead on the gold-plated connection pads to be gold-plated caused by manufacturing deviation can be reduced, and at the same time, the wet film on the lead falling off and gold seeping due to too small an area of the local gold-plating barrier film on the lead is avoided.

[0101] Embodiment Two

[0102] Based on the above embodiment, the embodiment of the present invention provides a specific embodiment of a method for manufacturing a gold-plated circuit board. Figure 6 is a flowchart of a method for manufacturing a gold-plated circuit board provided by Embodiment Two of the present invention. Refer to Figure 6 , and the method includes:

[0103] 1. Front process: including the preparation of each circuit and device of the gold-plated circuit board, etc.

[0104] 2. Outer layer pattern transfer: including etching to form gold-plated auxiliary connection pads, gold-plated connection pads to be gold-plated, and leads.

[0105] 3. Print wet film, expose wet film, and develop: After development, a local gold-plating barrier film is formed.

[0106] 4. Stick anti-gold-plating tape.

[0107] 5. Gold-plated fingers: That is, gold-plate the gold-plated connection pads to be gold-plated and the gold-plated auxiliary connection pads, and gold fingers are formed after gold-plating.

[0108] 6. Tear off the tape and remove the wet film: That is, tear off the anti-gold-plating tape and remove the wet film.

[0109] 7. Make a solder mask layer.

[0110] 8. Stick dry film and open a window in the dry film at the lead position: After sticking the dry film and opening a window in the dry film at the lead position, a second dry film exposing the lead is formed.

[0111] 9. Etch the lead.

[0112] 10. Remove the dry film.

[0113] 11. Rear process: including the excision of the edge area, etc.

[0114] It should be understood that the various forms of processes shown above can be used, with steps reordered, added or deleted. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of the present invention can be achieved, and no limitation is made herein.

[0115] The above specific embodiments do not constitute a limitation on the protection scope of the present invention. Those skilled in the art should understand that various modifications, combinations, sub - combinations and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for manufacturing a gold-plated circuit board, characterized in that, Including: Providing a substrate, wherein the substrate includes a central region and an edge region. The central region is provided with a plurality of gold-plating connection pads arranged in an array. The plurality of gold-plating connection pads arranged in an array are connected in series with each other through leads. The edge region is provided with at least one gold-plating auxiliary connection pad, and the gold-plating auxiliary connection pad is connected in series with the gold-plating connection pads in the central region through a lead; Providing a gold-plating barrier film on the surface of the substrate, and the gold-plating barrier film covers non-gold-plating regions except the gold-plating connection pads and the gold-plating auxiliary connection pads; Performing gold plating on the gold-plating connection pads and the gold-plating auxiliary connection pads; Removing the gold-plating barrier film and the leads in the central region; Removing the edge region; The lead includes a first lead segment and a second lead segment. The first lead segment is adjacent to the gold-plating connection pad, and each edge of the gold-plating connection pad connected to the lead is connected to the second lead segment through the first lead segment; The line width of the first lead segment is smaller than the line width of the second lead segment, and the length of the first lead segment is greater than or equal to a first set value; Providing a gold-plating barrier film on the surface of the substrate, and the gold-plating barrier film covers non-gold-plating regions except the gold-plating connection pads and the gold-plating auxiliary connection pads, including: Providing a local gold-plating barrier film on the surface of the substrate; wherein, the local gold-plating barrier film covers a partial region of each first lead segment and other leads outside the first lead segment; the local gold-plating barrier film includes a first barrier region and a second barrier region. Each first lead segment corresponds to a first barrier region. The first barrier region covers a partial region of the first lead segment and at least a partial second lead segment adjacent to the first lead segment. The second barrier region covers the second lead segment not covered by the first barrier region; the first barrier region includes a first boundary adjacent to the gold-plating connection pad and a second boundary parallel to the extending direction of the second lead segment. The distance between the first boundary and the boundary of the first lead segment adjacent to the gold-plating connection pad is greater than or equal to a second set value. The distance between the first boundary and the boundary of the first lead segment away from the gold-plating pad is greater than or equal to a second set value. The first boundary includes a first straight segment and second straight segments located on both sides of the first straight segment. The second straight segments are inclined away from the gold-plating connection pad relative to the first straight segment. The included angle between the second straight segment and the boundary of the gold-plating connection pad is greater than or equal to a preset angle. The distance between the second boundary and the second lead segment is greater than or equal to a third set value; Providing an anti-gold-plating tape on the surface of the substrate, and the anti-gold-plating tape covers other non-gold-plating regions; The first set value is 2 mil; The second set value is 1 mil, the preset angle is 30 degrees, and the third set value is 4 mil.

2. The method according to claim 1, wherein: At least two gold-plated auxiliary connection pads are arranged in the edge area, and the ratio of the width of the gold-plated auxiliary connection pad to the width of the connection pad to be gold-plated is greater than or equal to 2, and the ratio of the length of the gold-plated auxiliary connection pad to the length of the connection pad to be gold-plated is greater than or equal to 5.

3. The method according to claim 1, wherein: The difference in line width between the second lead segment and the first lead segment is 1 mil. The line width of the lead in the edge area is greater than the line width of the second lead segment, and the difference between the line width of the lead in the edge area and the line width of the second lead segment is greater than or equal to 2 mil.

4. The method according to claim 1, wherein: The local gold-plating barrier film is a wet film or a first dry film; When the local gold-plating barrier film is the first dry film, after the local gold-plating barrier film is arranged on the substrate surface, it further includes: performing low-temperature baking on the first dry film.

5. The method according to claim 1, characterized in that Arranging the local gold-plating barrier film on the substrate surface includes: Forming a gold-plating barrier material layer on the substrate surface; Performing an exposure process on the gold-plating barrier material layer so that the gold-plating barrier material layer to be retained is photocured; Developing the exposed gold-plating barrier material layer to remove the gold-plating barrier material layer that is not photocured, thereby forming the local gold-plating barrier film.

6. The method according to claim 1, characterized in that, Before removing the gold-plating barrier film and the lead in the central area, it further includes: Fabricating a solder mask layer that covers the area other than the lead and the connection pad to be gold-plated after gold plating; Removing the gold-plating barrier film and the lead in the central area includes: Arranging a second dry film on the side of the solder mask layer away from the substrate, and the second dry film covers the area other than the lead; Etching the lead; Removing the second dry film.

7. The method according to claim 6, wherein Arranging a second dry film on the side of the solder mask layer away from the substrate, and the second dry film covers the area other than the lead, includes: Arranging a dry film on the side of the solder mask layer away from the substrate; Exposing the dry film so that the dry film to be retained is photocured; Developing the exposed dry film to remove the dry film that is not photocured, thereby forming the second dry film.

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