Printed circuit board electroplating equipment with uniform electroplating and vertical electroplating production line
By setting up a shielding plate at some anode of the printed circuit board electroplating equipment, the problem of uneven coating thickness caused by the large resistance value of the titanium mesh type anode is solved, and a significant uniformity of coating thickness is achieved.
Patent Information
- Application Number
- CN202422008386.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-19
- Publication Date
- 2025-05-27
- Estimated Expiration
- 2034-08-19
AI Technical Summary
The resistance value of the insoluble anode of titanium mesh is relatively large, resulting in uneven thickness of the electroplating layer of printed circuit boards, especially the thickness of the plating layer gradually decreases in the vertical extension direction, resulting in thick top and thin bottom.
A shielding plate is provided at at least part of the anode to form a partial shield between the anode and the substrate, reducing the current in the shielding area, thereby improving the uniformity of the thickness of the plating layer.
By setting up a shielding plate, the problem of uneven coating thickness caused by the large resistance value of the titanium mesh type anode is effectively reduced, and the uniformity of the coating is significantly improved, and the covariance COV of the coating thickness is reduced from 8% to 4%.
Smart Images
Figure CN222908130U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of printed circuit board electroplating equipment, and particularly to a printed circuit board electroplating equipment with uniform electroplating and a vertical electroplating production line. Background Art
[0002] At present, the electroplating processes of printed circuit boards (PCBs) mainly include horizontal electroplating and vertical electroplating. In recent years, with the development of vertical electroplating equipment, electroplating additive processes, and the increasing demand for non-contact electroplating, the market share of vertical electroplating processes has been increasing. In particular, vertical continuous electroplating (VCP) has gradually become the mainstream technology for PCB electroplating. The insoluble anodes used in vertical electroplating production lines mainly include titanium plates and titanium meshes coated with iridium oxide on the surface. Among them, the price of titanium plates is relatively high, but their own resistance values are small and the electroplating uniformity is good. The titanium mesh has a relatively large self-resistance value, which easily leads to the phenomenon that the coating is thicker at the top and thinner at the bottom during electroplating. The coating thickness difference of titanium mesh anodes is generally about 10%. It is urgent to improve such electroplating equipment to improve the uniformity of the electroplating coating thickness.
[0003] CN221460567U discloses a high-uniformity electroplating equipment for PCB boards, which includes an electroplating device body. An electroplating vibration mechanism is arranged at the top of the electroplating device body, and evenly distributed PCB boards are arranged at the bottom of the electroplating vibration mechanism. Among them, the electroplating vibration mechanism includes a support frame arranged at the top of the electroplating device body; the first driving cylinder drives the hammer head to strike the moving seat. At this time, the vibration frame drives the PCB board to vibrate and shake in the electroplating solution. At this time, the spring will deform accordingly. Under the action of the spring, the vibration and shaking frequency of the vibration frame are increased. When the PCB board vibrates and shakes, the bubbles in the small holes are driven out of the small holes.
[0004] The vibration frame of the high-uniformity electroplating equipment for PCB boards disclosed in the above-mentioned utility model patent will also shake while vibrating, improving the efficiency of the PCB board to drive the bubbles out of the small holes. This electroplating equipment can alleviate the problems of discontinuous and uneven electroplating caused by bubbles, but cannot improve the problem of uneven thickness of the coating on the upper and lower parts caused by the properties of the titanium mesh insoluble anode itself. Utility Model Content
[0005] In view of the state of the above-mentioned prior art, the present application is made. The purpose of the present application is to provide a printed circuit board electroplating equipment with uniform electroplating, which is provided with shielding plates at at least some anodes, and can improve the problem of low electroplating uniformity caused by the relatively large self-resistance value of the titanium mesh anodes.
[0006] The present application also provides a vertical electroplating production line including the above-mentioned electroplating equipment.
[0007] The present application provides a printed circuit board electroplating device with uniform electroplating for plating a metal onto a substrate, which includes an anode, an anode box, a shielding plate, and a rectifier.
[0008] The positive pole of the rectifier is connected to the anode, and the negative pole of the rectifier can be connected to the substrate of the printed circuit board.
[0009] The anode is a titanium mesh, and the anode box is arranged outside the anode to isolate the anode from the outside world at least partially.
[0010] The shielding plate is arranged on the side of the anode box close to the substrate, and on the side of the upper part of the anode close to the substrate, so that the shielding plate can form at least partial shielding between the anode and the substrate to enhance the uniformity of the plating layer on the substrate.
[0011] In at least one possible implementation, the shielding plate is a perforated plate.
[0012] In at least one possible implementation, an ion membrane is arranged on the side of the anode box close to the substrate, and some components in the electroplating solution can freely pass through the ion membrane to achieve the conductive function.
[0013] In at least one possible implementation, the shielding plate is a polyvinyl chloride plate.
[0014] In at least one possible implementation, the printed circuit board electroplating device with uniform electroplating includes a plurality of the anodes, and the plurality of anodes are arranged in sequence along the horizontal direction, and the shielding plate is arranged on one side of only one or more of the anodes located in the middle.
[0015] In at least one possible implementation, the printed circuit board electroplating device with uniform electroplating includes 8 of the anodes, and the shielding plate is arranged on one side of only the fourth and fifth anodes located in the middle.
[0016] In at least one possible implementation, the housing part of the anode box is a polyvinyl chloride housing, and the shielding plate is connected to the anode box through plastic screws.
[0017] In at least one possible implementation, the shielding plate is arranged on only the side of the upper part of the anode close to the substrate.
[0018] Holes are uniformly arranged in the main body part of the shielding plate, or the porosity of the shielding plate increases from top to bottom.
[0019] The present application also provides a vertical electroplating production line, which includes the aforementioned printed circuit board electroplating device with uniform electroplating, and the substrate can move between a plurality of the printed circuit board electroplating devices with uniform electroplating.
[0020] In at least one possible implementation, the vertical electroplating production line further includes a plurality of conventional electroplating devices without the shielding plates, and the plurality of electroplating devices for uniformly electroplating printed circuit boards are arranged at the rear stage of the vertical electroplating production line.
[0021] The electroplating device for uniformly electroplating printed circuit boards and the vertical electroplating production line provided by the present application can set shielding plates at at least some anodes to at least shield the area between at least some anodes and the substrate, reduce the current in the shielding area, and effectively improve the problem of low electroplating uniformity caused by the large resistance value of titanium mesh anodes. Description of the Drawings
[0022] Figure 1 Schematic structural diagram of an electroplating device according to an implementation of the present application.
[0023] Figure 2 Another schematic structural diagram of an electroplating device according to an implementation of the present application.
[0024] Figure 3 Schematic structural diagram of a vertical electroplating production line according to an implementation of the present application.
[0025] Figure 4 Schematic structural diagram of a shielding plate according to an implementation of the present application.
[0026] Figure 5 Statistical chart of the product coating thickness of a vertical electroplating production line without a shielding plate.
[0027] Figure 6 Statistical chart of the product coating thickness of a vertical electroplating production line according to an implementation of the present application.
[0028] Description of the Reference Numerals
[0029] 10 Substrate
[0030] 20 Electroplating device
[0031] 21 Anode
[0032] 22 Anode box
[0033] 221 Ion membrane
[0034] 23 Shielding plate
[0035] 24 Rectifier
[0036] 25 Nozzle
[0037] 26 Clamping part
[0038] 100 Vertical electroplating production line
[0039] The latter section of the 110 electroplating production line Specific implementation manners
[0040] The exemplary implementation manners of the present application will be described below with reference to the accompanying drawings. It should be understood that these specific descriptions are only used to teach those skilled in the art how to implement the present application, rather than to exhaust all feasible manners of the present application, nor to limit the scope of the present application.
[0041] The implementation manners of the present application provide a printed circuit board electroplating device with uniform electroplating (hereinafter, sometimes simply referred to as "electroplating device"), as Figure 1 and Figure 2 shown, the electroplating device 20 may include an anode 21, an anode box 22, a shielding plate 23, a rectifier 24, and a nozzle 25.
[0042] Specifically, the rectifier 24 of the electroplating device 20 can convert alternating current into direct current. The positive electrode of the rectifier 24 can be connected to the anode 21, and the negative electrode of the rectifier 24 can be connected to the substrate 10. The anode 21 and the substrate 10 can be at least partially oppositely arranged. It can be understood that the anode 21 in this implementation manner can be a titanium anode, especially a titanium mesh (titanium anodes can usually be in shapes such as mesh, plate, strip, and tube). The titanium mesh as an anode has a cost advantage compared with a titanium plate, but the resistance value of the titanium mesh is relatively large, which may cause the thickness of the electroplated layer to be uneven along the extension direction of the titanium mesh (especially the vertical extension direction) (the thickness gradually decreases, that is, thicker at the top and thinner at the bottom). As shown in Table 1 below, in an experimental example, the resistance values of the titanium mesh and the titanium plate at different positions (different height positions of the titanium anode) are measured.
[0043] Table 1: Resistance values of the titanium mesh and the titanium plate at different measurement positions
[0044] Measurement position Titanium plate (mΩ) Titanium mesh (mΩ) 0 2.08 2.06 100mm 2.10 3.44 200mm 2.20 4.19 300mm 2.37 4.87 400mm 2.50 5.65 500mm 2.63 6.09 600mm 3.09 7.25 700mm 3.17 7.30
[0045] In Table 1 above, the measurement position 0 is the uppermost end of the anode (titanium mesh or titanium plate), and the length of the measurement position (100 mm to 700 m) means the distance of the measurement position from the uppermost end of the anode. It can be seen from the above table that the change of the resistance value of the titanium mesh with the measurement position (height) is greater than that of the titanium plate, that is, the electroplating device using the titanium mesh anode is more likely to cause the thickness of the electroplated layer to be uneven due to the change of the resistance value of the anode.
[0046] As Figure 1 and Figure 2As shown, the anode box 22 can be arranged outside the anode 21, and the anode box 22 can at least partially isolate the anode 21 from the external chemical solution (i.e., the electroplating solution). An ion membrane 221 can be arranged on one side of the anode box 22 close to the substrate 10. The ion membrane 221 can prevent some components of the chemical solution (additives) from approaching the anode 21, so as to avoid or reduce the decomposition of some chemical solution components near the anode and reduce the consumption of electroplating additives. The ion membrane 221 can allow components such as copper sulfate and sulfuric acid in the chemical solution (electroplating solution) to freely enter and exit to achieve normal conductive functions. The nozzle 25 can be arranged between the anode 21 and the substrate 10 to spray the chemical solution onto the substrate 10.
[0047] As Figure 1 and Figure 2 As shown, a shielding plate 23 can be arranged on one side of the anode 21 close to the substrate 10. The shielding plate 23 can be connected to one side of the anode box 22 close to the substrate 10 (especially can be connected to the upper part of this side) to form at least partial obstruction between the anode 21 and the substrate 10. Further, the shielding plate 23 can at least partially shield the upper part of the anode 21, that is, the shielding plate 23 can be at least partially arranged between the upper part of the anode 21 and the upper part of the substrate 10. In particular, the shielding plate can be arranged on one side of only the upper part of the anode 21 close to the substrate 10. It can be understood that during the electroplating operation, the current flows from the rectifier 24 to the anode 21, and then flows through the chemical solution (electroplating solution) to the substrate 10. Since the resistance value of the anode 21 (especially the titanium mesh anode) is relatively large, the current flowing to the upper part (in the vertical direction) of the substrate 10 is greater than the current flowing to the lower part of the substrate 10, which may lead to the plating layer thickness of the upper part of the substrate 10 being greater than that of its lower part. After the shielding plate 23 is arranged on the upper part of the anode box 22, the current flowing to the upper part of the substrate 10 will be reduced and be close to the current flowing to the lower part of the substrate 10 to improve the uniformity of the electroplating layer thickness of the substrate.
[0048] As Figure 4 As shown, the shielding plate 23 can be a porous plate. The shielding plate 23 can be a polyvinyl chloride (PVC) plate, and this material is not easy to deform and has a long service life. The housing part of the anode box 22 except the ion membrane 221 can also be made of polyvinyl chloride (PVC) material. The shielding plate 23 can be fixed to the upper part of the anode box 22 using plastic screws. It can be understood that using non-metallic materials such as polyvinyl chloride can prevent or reduce metal corrosion of the electrolysis equipment or pollution of the electroplating tank body, etc. Further, holes can be arranged in the main body part of the shielding plate 23, and screw holes can be arranged in the edge part of the shielding plate 23. The holes can be evenly arranged in the main body part of the shielding plate, or the porosity of the shielding plate 23 can increase from top to bottom.
[0049] Further, as Figure 2As shown, the electroplating apparatus 20 may include a plurality of anodes 21. Exemplarily, in this embodiment, the electroplating apparatus includes a total of eight anodes 21. The plurality of anodes 21 may be arranged in sequence in the horizontal direction. The substrate 10, as the base of a printed circuit board, may include a plurality of hole positions to be plated (especially hole positions formed by laser processing) to form via holes (including through holes, buried holes, and blind holes), and the setting of the masking plate 23 may affect the electroplating of the via holes. Therefore, the electroplating apparatus 20 may be provided with the masking plate 23 only at some of its anodes 21 (anode cassettes) to prevent the electroplating effect of the via holes from being affected. Preferably, as Figure 2 shown, in this embodiment, the masking plate 23 may be provided only at the middle anodes 21 (anode cassettes). Exemplarily, the masking plate 23 may be provided at the fourth and fifth anodes 21 among the eight anodes 21.
[0050] The electroplating apparatus 20 may further include a clamping portion 26 for clamping the substrate 10. The clamping portion 26 may clamp the substrate 10 to move it horizontally between the plurality of anodes and / or the electroplating apparatus.
[0051] It can be understood that the electroplating apparatus can flexibly adjust the connection position, masking area, etc. of the masking plate 23 according to actual needs to adjust the specific electroplating parameters.
[0052] An embodiment of the present application further provides a vertical electroplating production line. As Figure 3 shown, a vertical electroplating production line 100 may include a plurality of the above-mentioned electroplating apparatuses 20 and a plurality of conventional electroplating apparatuses without masking plates. Exemplarily, the vertical electroplating production line 100 in this embodiment may include 25 conventional electroplating apparatuses and 15 of the aforementioned electroplating apparatuses 20. The rear section 110 of the electroplating production line composed of the aforementioned electroplating apparatuses 20 may be provided at the rear section of the vertical electroplating production line 100. Exemplarily, the rear section 110 of the electroplating production line in this embodiment may include 15 electroplating apparatuses 20.
[0053] It can be understood that in the vertical electroplating production line 100, using only the electroplating apparatuses 20 with masking plates 23 in the rear section 110 of the electroplating production line can improve the overall electroplating uniformity of the substrate 10 without affecting the electroplating effect of the via holes.
[0054] A comparative example is given below. In a control experiment, as Figure 5 and Figure 6As shown (the horizontal coordinate in the figure is the average thickness of the coating, with the unit of micrometer / um; the vertical coordinate is 0 to 14 measurement points evenly arranged in the vertical direction), the uniformity (surface uniformity) of the average thickness of the product coating of the vertical electroplating production line using the electroplating equipment 20 provided with the shielding plate 23 is significantly better than that of the vertical electroplating production line without the shielding plate. After setting the shielding plate, the covariance COV (deviation / mean) of the coating thickness can be reduced from 8% to 4%.
[0055] The following briefly describes some beneficial effects of the above embodiments of the present application.
[0056] The embodiment of the present application provides an electroplating equipment for printed circuit boards with uniform electroplating. By setting a shielding plate on the side of the anode close to the substrate, the shielding plate can at least shield part of the area between the upper part of the anode and the upper part of the substrate, reduce the current in the shielded area, and effectively improve the problem of low electroplating uniformity (thick on the upper part and thin on the lower part) caused by the large resistance value of the titanium mesh anode.
[0057] It can be understood that in the present application, when the number of components or members is not specifically limited, the number can be one or more, and here the plurality means two or more. For the case where the number of components or members shown in the drawings and / or described in the specification is a specific number such as two, three, four, etc., this specific number is usually exemplary rather than restrictive, and it can be understood as a plurality, that is, two or more. However, this does not mean that the present application excludes the case of one.
[0058] It should be understood that the above embodiments are merely exemplary and do not limit the present application. Those skilled in the art can make various variations and changes to the above embodiments under the teaching of the present application without departing from the scope of the present application.
Claims
1. A printed circuit board electroplating device with uniform electroplating, used for plating metal onto a substrate, characterized in that: It includes anode, anode box, shielding plate and rectifier. The positive electrode of the rectifier is connected to the anode, and the negative electrode of the rectifier can be connected to the substrate of the printed circuit board. The anode is a titanium mesh, and the anode box is arranged outside the anode to at least partially isolate the anode from the outside. The shielding plate is arranged on one side of the anode box close to the substrate, and the shielding plate is arranged on one side of the upper part of the anode close to the substrate, so that the shielding plate can form at least partial shielding between the anode and the substrate to enhance the uniformity of the coating of the substrate.
2. The printed circuit board electroplating equipment with uniform electroplating according to claim 1, characterized in that: The shielding plate is a porous plate.
3. The printed circuit board electroplating equipment with uniform electroplating according to claim 1, characterized in that: An ion membrane is arranged on one side of the anode box close to the substrate, and some components in the electroplating solution can freely pass through the ion membrane to achieve the conductive function.
4. The printed circuit board electroplating equipment with uniform electroplating according to claim 1, characterized in that: The shielding plate is a polyvinyl chloride plate.
5. The printed circuit board electroplating equipment with uniform electroplating according to claim 1, characterized in that: It comprises a plurality of anodes, which are arranged in sequence along the horizontal direction, and the shielding plate is provided on one side of only one or more anodes located in the middle.
6. The printed circuit board electroplating equipment with uniform electroplating according to claim 5, characterized in that: The anodes include eight anodes, and only one side of the fourth anode and the fifth anode located in the middle is provided with the shielding plate.
7. The printed circuit board electroplating equipment with uniform electroplating according to claim 1, characterized in that: The shell part of the anode box is a polyvinyl chloride shell, and the shielding plate is connected to the anode box through plastic screws.
8. The printed circuit board electroplating equipment with uniform electroplating according to claim 2, characterized in that: The shielding plate is disposed on only one side of the upper portion of the anode close to the substrate. The main body of the shielding plate is evenly provided with holes, or the porosity of the shielding plate increases from top to bottom.
9. A vertical electroplating production line, characterized in that: The invention comprises a plurality of printed circuit board electroplating devices with uniform electroplating as claimed in any one of claims 1 to 8, wherein the substrate can move between the plurality of printed circuit board electroplating devices with uniform electroplating.
10. The vertical electroplating production line according to claim 9, characterized in that: It also includes a plurality of conventional electroplating equipment without the shielding plate, and a plurality of printed circuit board electroplating equipment with uniform electroplating are arranged at the rear section of the vertical electroplating production line.