Gold plating method for large-scale multi-stage contact of optical module connector
By designing a composite protective film, the problems of low gold plating efficiency and poor quality in existing gold plating processes are solved, achieving a gold plating effect with high purity and high adhesion, thus improving the gold plating yield and product quality.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- APCB ELECTRONIC (KUNSHAN) CO LTD
- Filing Date
- 2026-02-04
- Publication Date
- 2026-06-23
AI Technical Summary
In existing gold plating processes, the plating efficiency is low and the product quality is poor. Anti-plating bridges are easily damaged during the clamping and removal of masking tape, leading to gold plating defects and electrical short circuits.
A composite protective film is used to protect the area to be gold-plated. The design of the glue-free sealing area and the adhesive fixing area avoids the contact of adhesive with the gold-plated copper surface and prevents plating bridges. Selective electroplating is carried out using conductive skylights to form independent gold-plated sections.
It improves the gold plating yield, prevents damage from plating bridges, ensures a high-purity and high-adhesion gold plating layer, and improves product quality and process reliability.
Smart Images
Figure CN122269588A_ABST
Abstract
Description
Technical Field
[0001] This application relates to printed circuit board technology, specifically to a gold plating method for large-format, multi-level contacts in an optical module connector. Background Technology
[0002] "Segmented fingers" refers to the segmented, non-continuous arrangement of metal contacts in the gold finger interface of optical modules and high-speed copper cables. It is mainly used to achieve "power-on timing control" (grounding first, then power supply, then signal) and "insertion and extraction force optimization" during hot plugging and unplugging, so as to reduce signal interference and prevent surge current damage to equipment.
[0003] The processing flow of segmented fingers in a printed circuit board is as follows: outer layer AOI → gold-plated dry film → gold-plated LPI → gold-plated fingers → reverse etch dry film → reverse etch LPI → alkaline etching → film removal → solder mask. After the outer layer pattern is completed, a gold-plated dry film is used to cover the non-gold-plated areas. The gold-plated areas are then uniformly printed with anti-gold plating LPI liquid ink using a screen printing process. Its main function is to isolate the plug-in terminals in segments. During the gold plating process, it acts as an anti-plating bridge with a width of approximately 0.1-0.15mm. While ensuring good conductivity for the entire plug-in terminal, it prevents nickel-gold plating on this part of the copper surface, providing a good etched copper surface for the subsequent alkaline etching process.
[0004] In existing gold plating processes, the industry generally adopts a production method that combines VCP (Vertical Continuous Plating) gold plating lines with chain-type gold plating lines. Due to the influence of the tank depth and chain conveyor method of chain-type gold plating lines, the gold plating operation must be divided into two halves regardless of the size of the product.
[0005] First half processing: Blue adhesive or water-resistant red tape is used to mask and attach the other half of the non-gold-plated surface before gold plating. Second half processing: After gold plating the first half, the masking tape on the other half must be removed before gold plating. During half-side processing, the product needs to be clamped on the chain conveyor. Due to the large clamping force, the LPI anti-plating bridge is damaged. During the removal of the masking tape, the tape adheres to and damages or even pulls off the LPI anti-plating bridge. When the second half is gold-plated, due to the damaged anti-plating bridge, the gold layer abnormally deposits onto the copper solder mask surface that should be protected, forming a "gold-adhesive" defect. This prevents the subsequent alkaline etching process from removing the deposited gold layer. The gold layer, acting as an anti-etching layer, protects the underlying copper layer, leaving residual copper solder mask layer, ultimately causing an electrical short circuit at the junction of the two halves. In the existing gold plating process, not only is the plating efficiency low, but product quality is also not guaranteed. Summary of the Invention
[0006] To overcome the above-mentioned defects, this application provides a gold plating method for large-format, multi-level contacts of optical module connectors. This gold plating method utilizes a composite protective film that can both seal the area to be gold-plated and reduce the adhesion of adhesives to the plating bridges, greatly improving the gold plating yield and significantly improving the quality of the gold-plated products.
[0007] The technical solution adopted by this application to solve its technical problem is:
[0008] A method for gold plating multiple hierarchical contacts in a large-format optical module connector includes the following steps:
[0009] Patterned mask: Provides a substrate to be gold plated, the substrate having a processing surface, the processing surface including a non-gold plated area and a gold plated area, the gold plated area having a continuous copper surface to be gold plated, an anti-plating film is provided in the non-gold plated area of the substrate, and an anti-plating bridge is formed on the copper surface to be gold plated, the anti-plating bridge dividing the continuous copper surface to be gold plated into multiple independent gold plated segments that are electrically insulated from each other.
[0010] Pre-plating treatment: The substrate after film application is pre-treated to clean and activate the gold-plated surface;
[0011] First film application: The processing surface of the substrate is divided into a first region and a second region. A composite protective film is applied to the second region. The lower surface of the composite protective film includes a glue-free sealing area and an adhesive fixing area. The glue-free sealing area is attached to the gold-plating area of the second region, and the adhesive fixing area is attached to the substrate surface outside the gold-plating area of the second region.
[0012] First lamination: The substrate to which the composite protective film is to be laminated is laminated using a lamination machine, and then a conductive window is opened on the edge of the board in the first area;
[0013] First gold plating: A power supply circuit is established through the conductive skylight, and selective electroplating is performed on the exposed first area to form gold fingers. Then, the composite protective film is removed and the area is washed with water.
[0014] Second film application: A composite protective film is applied to the first area, so that the glue-free sealing area is attached to the gold-plated area of the first area, and the adhesive fixing area is attached to the substrate surface outside the gold-plated area of the first area.
[0015] Second lamination: The substrate with the composite protective film is laminated using a lamination machine, and then a conductive window is opened on the edge of the board in the second region;
[0016] Second gold plating: A power supply circuit is established through the conductive skylight, and selective electroplating is performed on the exposed second area to form gold fingers. Then the composite protective film is removed and the area is washed with water.
[0017] Post-processing: The gold-plated substrate undergoes further processing to obtain the finished circuit board.
[0018] Optionally, the composite protective film includes an isolation layer and two adhesive layers. The two adhesive layers are respectively fixed to the two sides of the lower surface of the isolation layer. Between the two adhesive layers, the exposed area of the lower surface of the isolation layer constitutes the glue-free sealing area; the lower surfaces of the two adhesive layers constitute the adhesive fixing area.
[0019] Optionally, it further includes a buffer layer, which is stacked on the isolation layer, and the buffer layer and the adhesive layer are located on opposite sides of the isolation layer, respectively.
[0020] Optionally, it further includes a release film layer, which is stacked on the buffer layer, and the release film layer and the isolation layer are located on opposite sides of the buffer layer, respectively.
[0021] Optionally, if the distance between the two adhesive layers is L1 and the width of the area to be plated with gold on the substrate is L2, then L1 is greater than L2.
[0022] Optionally, when the composite protective film covers the area to be plated with gold on the substrate, the distance between the adhesive layer and the area to be plated with gold is L3, where L3 is 2-3 mm.
[0023] Optionally, each adhesive layer has a width of 6-8 mm, a thickness of 25-35 μm, a buffer layer thickness of 1-2 mm, an adhesive layer being waterproof double-sided tape, a buffer layer being foamed tape, and a release layer being adhesive-free PE film.
[0024] Optionally, the anti-plating bridge includes a lateral shielding portion and a longitudinal anchoring portion extending from one or both ends of the lateral shielding portion toward the non-gold-plated area; the lateral shielding portion spans and covers the copper conductor of the area to be gold-plated, thereby dividing the continuous copper surface to be gold-plated into multiple independent gold-plated segments that are electrically insulated from each other.
[0025] Optionally, the anti-plating bridge is at least one of the following: "I", "T" and "L" shaped.
[0026] Optionally, the thickness of the anti-plating bridge is 15-25μm, the thickness of the anti-plating film is 50μm±5μm, and a shunt pad is added at the end of the independent gold plating section.
[0027] The beneficial effects of this application are as follows: This application utilizes a composite protective film to protect the area to be plated, achieving zero contamination of the area. Since the adhesive fixing area is spatially separated from the area to be plated, the adhesive layer on it will not come into contact with the copper surface to be plated or the delicate anti-plating bridge structure, fundamentally eliminating chemical contamination of the critical gold-plating surface by the adhesive and ensuring a high-purity, high-adhesion gold plating layer. When the protective film is removed, the peeling force acts entirely on the outer adhesive fixing area, while the adhesive-free sealing area in the center only covers the anti-plating bridge through physical contact, without any adhesive force. Therefore, it can effectively prevent the fragile and delicate anti-plating bridge structure from being pulled up or damaged during the film removal process, greatly improving process reliability and product yield, thereby avoiding physical damage to the anti-plating bridge structure. Therefore, the composite protective film used in this application solves the problem of anti-plating bridge detachment caused by excessive clamping force of the clamp in the gold-plating chain. It can both seal the area to be gold-plated and reduce the adhesion of adhesive to the anti-plating bridge, which greatly improves the gold plating yield and significantly improves the quality of gold-plated products. Attached Figure Description
[0028] Figure 1 This is a cross-sectional view of the composite protective film in this application;
[0029] Figure 2 This is a bottom view of the composite protective film in this application;
[0030] Figure 3 This is a simplified diagram of the substrate-bonded composite protective film in this application;
[0031] Figure 4 for Figure 3 Enlarged view of point A in the middle;
[0032] In the diagram: 100 - composite protective film, 110 - adhesive layer, 111 - adhesive fixing area, 120 - isolation layer, 121 - glue-free sealing area, 130 - buffer layer, 140 - release film layer, 200 - substrate, 210 - non-gold plating area, 220 - area to be gold plating, 230 - anti-plating bridge. Detailed Implementation
[0033] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the embodiments of this application. Obviously, the embodiments described in this application are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.
[0034] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such uses of the terms can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.
[0035] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.
[0036] A method for gold plating multiple hierarchical contacts in a large-format optical module connector includes the following steps:
[0037] Patterning Mask: A substrate 200 to be gold-plated is provided. The substrate 200 has a processing surface, including a non-gold-plated area 210 and a gold-plated area 220. The gold-plated area 220 has a continuous copper surface to be gold-plated. A resist film is formed on the non-gold-plated area of the substrate 200, and a resist bridge 230 is formed on the copper surface to be gold-plated. The resist bridge 230 divides the continuous copper surface to be gold-plated into multiple independently gold-plated segments that are electrically insulated from each other. The independent gold-plated segments are segmented fingers, i.e., the resist film covers the non-gold-plated area 210 of the substrate 200, and the resist bridge 230 covers the area between the segmented fingers in the gold-plated area 220. Optionally, the resist film is a dry film, and the resist bridge 230 is made of liquid photoresist (LPI) ink.
[0038] In some embodiments of this application, the anti-plating film and the anti-plating bridge 230 are formed in two steps: first, a dry film is applied to the non-gold-plated area 210 of the substrate 200 to form an anti-plating film; then, an LPI ink layer is formed on the copper surface of the substrate 200 to be gold-plated; and then, through exposure and development processes, a preset pattern is transferred onto the LPI ink layer, thereby simultaneously forming a pattern window that exposes the gold-plated area of the substrate and an anti-plating bridge 230 that divides the continuous copper surface to be gold-plated into multiple independent gold-plating segments.
[0039] Pre-plating treatment: The substrate 200 after film application is pre-treated to clean and activate the gold-plated surface; the pre-treatment includes pickling, high-pressure spraying of 800-mesh diamond abrasive, high-pressure water washing, pickling, micro-etching, high-pressure sandblasting, water washing, drying and other processes.
[0040] First film application: The processed surface of the substrate 200 is divided into a first region and a second region. For ease of description, the processed surface is divided into two halves and defined as the first region and the second region. Subsequent gold plating is done in two steps: first, the first region is gold-plated, and then the second region is plated. Before gold plating the first region, the second region is protected with a composite protective film 100. That is, the composite protective film 100 is applied to the second region, such as... Figure 3 As shown, the composite protective film 100 is used to protect the gold-plated area in the second region, such as... Figure 1 As shown, the lower surface of the composite protective film 100 includes a glue-free sealing area 121 and an adhesive fixing area 111. The glue-free sealing area 121 is attached to the gold-plating area 220 of the second region, and the adhesive fixing area 111 is attached to the substrate surface surrounding the gold-plating area in the second region. The surface of the substrate 200 can be a glossy surface or an anti-plating film. That is, the glue-free sealing area covers the gold-plating area to protect it. In actual use, both ends of the composite protective film 100 can be sealed with ordinary adhesive tape.
[0041] Since the bonding and fixing area 111 does not contact the gold-plating area 220, that is, the adhesive on the bonding and fixing area 111 does not contact the copper surface to be gold-plated and the anti-plating bridge 230, the adhesive on the bonding and fixing area 111 will not contaminate the copper surface to be gold-plated, and the anti-plating bridge 230 will not be pulled up when the composite protective film 100 is removed.
[0042] The adhesive fixing area 111 serves to fix the composite protective film 100 to the substrate 200 as a whole. Its adhesive position is designed to ensure that it only contacts the substrate surface or smooth surface of the substrate surrounding the area to be gold-plated 220, which already has anti-plating film protection, and does not contact the area to be gold-plated 220, including the copper surface and the anti-plating bridge 230 itself. This design fundamentally avoids contamination of the precision gold-plating area by adhesive and eliminates the risk of physical damage to the anti-plating bridge 230 structure during film removal.
[0043] First lamination: The substrate 200 to which the composite protective film 100 is bonded is pressed using a lamination machine to ensure that the composite protective film 100 and the surface of the substrate 200 are tightly bonded without defects such as bubbles, wrinkles, or poor bonding; then, conductive windows are opened on the edge of the first area; the conductive windows on the edge of the board are to provide contact points for the conductive brush. The conductive method of the tracked gold-plated wire is to use the conductive brush to contact the edge of the board, and the copper foil on the edge of the board is connected to the finger guide wire to supply power to the finger;
[0044] First gold plating: A power supply circuit is established through the conductive skylight, and selective electroplating is performed on the exposed first area to form gold fingers. Then, the composite protective film 100 is removed and the area is washed with water; that is, the gold plating process of the fingers in the first area is completed, forming gold fingers, and the area to be gold-plated in the first area becomes the gold-plating area.
[0045] Second film application: A composite protective film 100 is applied to the first area. The composite film 100 is used to protect the gold-plated area of the first area, so that the glue-free sealing area 121 is attached to the gold-plated area of the first area, and the adhesive fixing area 111 is attached to the surface of the substrate 200 outside the gold-plated area in the first area.
[0046] Second lamination: The substrate with the laminated protective film 100 is laminated using a lamination machine, and then a conductive window is opened on the edge of the board in the second region;
[0047] Second gold plating: A power supply circuit is established through the conductive skylight, and selective electroplating is performed on the exposed second area to form gold fingers. Then, the composite protective film 100 is removed and washed with water; that is, the gold plating process of the fingers in the second area is completed, forming gold fingers. At this time, the entire substrate 200 has completed the gold plating process.
[0048] Post-processing: The gold-plated substrate 200 undergoes further processing to obtain the finished circuit board. Subsequent processing includes etching, solder resist baking, electroless gold plating, molding, testing, and finished product warehousing, all of which are conventional techniques and will not be described in detail here. In this application, a composite protective film 100 is used to protect the area to be gold-plated, achieving zero contamination of the area. Because the adhesive fixing area 111 is spatially separated from the area to be gold-plated, the adhesive layer on it will not come into contact with the copper surface to be gold-plated or the precise anti-plating bridge 230 structure, fundamentally eliminating chemical contamination of the key gold-plating surface by the adhesive, thus ensuring a high-purity, high-adhesion gold plating layer.
[0049] When the protective film is removed, the peeling force acts entirely on the outer adhesive fixing area, while the central adhesive-free sealing area 121 only covers the anti-plating bridge 230 through physical contact, without any adhesive force. Therefore, it effectively prevents the fragile and delicate anti-plating bridge 230 structure from being pulled up or damaged during the film removal process, greatly improving process reliability and product yield, thereby avoiding physical damage to the anti-plating bridge 230 structure. Therefore, the composite protective film 100 used in this application solves the problem of anti-plating bridge 230 detachment caused by excessive clamping force in the gold plating chain, achieving both sealing of the area to be gold-plated and reducing adhesive adhesion to the anti-plating bridge, greatly improving the gold plating yield and significantly enhancing the quality of the gold-plated products.
[0050] This application simplifies operations and reduces the risk of handling precision patterns by combining glue-free sealing with external bonding, while ensuring reliable shielding. It is particularly suitable for manufacturing high-density, high-precision connector plug-in terminals. This application can further increase the layout of printed circuit boards, such as expanding the layout design to 400*550mm, maintaining the operation scheme of processing two halves, so as to maximize the processing continuity and operation efficiency of each half.
[0051] like Figure 1-2 As shown, the composite protective film 100 includes an isolation layer 120 and two adhesive layers 110. The two adhesive layers 110 are respectively fixed to the two sides of the lower surface of the isolation layer 120. Between the two adhesive layers 110, the exposed area of the lower surface of the isolation layer 120 constitutes the glue-free sealing area 121; the lower surfaces of the two adhesive layers 110 constitute the adhesive fixing area 111.
[0052] The composite protective film 100 further includes a buffer layer 130 and a release film layer 140. The buffer layer 130 is stacked on the isolation layer 120, and the buffer layer 130 and the adhesive layer 110 are located on opposite sides of the isolation layer 120.
[0053] The release film layer 140 is stacked on the buffer layer 130, and the release film layer 140 and the isolation layer 120 are respectively located on opposite sides of the buffer layer 130. Figure 1As shown, in this embodiment, the composite protective film 100 includes an adhesive layer 110, an isolation layer 120, a buffer layer 130, and a release film layer 140 stacked sequentially. The isolation layer 120 has an exposed adhesive-free sealing area 121, which is adhered to the gold-plating area of the second region or the gold-plating area of the first region. The adhesive layer 110 is adhered to the substrate surface surrounding the gold-plating area of the second region or the gold-plating area of the first region. Due to the presence of the buffer layer 130, the jig directly clamps the buffer layer 130 during gold plating, reducing the clamping force of the jig against the plating bridge 230 and solving the problem of the plating bridge 230 falling off under the action of the jig. The release film layer 140 is adhered to the outside of the buffer layer 130 to protect the buffer layer 130 and prevent the buffer layer debris from contaminating the substrate. Therefore, the composite protective film 100 can simultaneously meet the requirements of sealing, non-adhesion, buffering, and non-shedding of the gold-plating area, and has very strong performance.
[0054] like Figure 1 and Figure 4 As shown, the distance between the two adhesive layers 110 is L1, that is, the width of the glue-free sealing area 121 is L1, and the width of the gold-plating area 220 on the substrate 200 is L2, so L1 is greater than L2. Optionally, two parallel adhesive layers 110 are adhered along the length direction of the isolation layer 12.
[0055] like Figure 4 As shown, when the composite protective film 100 covers the gold-plating area 220 on the substrate 200, the distance between the adhesive layer 110 and the gold-plating area 220 is L3, where L3 is 2-3 mm. To prevent misalignment of the adhesive, a 2-3 mm margin is left to ensure that the adhesive layer 110 does not contact the gold-plating area.
[0056] Each adhesive layer 110 has a width of 6-8 mm and a thickness of 25-35 μm. The buffer layer 130 has a thickness of 1-2 mm. The adhesive layer 110 is a waterproof double-sided tape, the buffer layer 130 is a foamed tape, and the release layer 120 is a non-adhesive PE film. The waterproof double-sided tape can be ordinary red tape, blue tape, black tape, etc. The main material of the foamed tape is EVA, PU, or PE foam substrate. The release film layer 140 can be PE release film, PET release film, PP release film, etc.
[0057] A 1-2mm buffer layer 130 is set above the gold fingers of the protective film, which can absorb the clamping pressure of the chain belt and avoid cracking damage to the anti-plating bridge.
[0058] The anti-plating bridge 230 includes a transverse shielding portion 231 and a longitudinal anchoring portion 232 extending from one or both ends of the transverse shielding portion 231 toward the non-gold-plated area. The transverse shielding portion 232 spans and covers the copper conductor of the area to be gold-plated, thereby dividing the continuous copper surface to be gold-plated into multiple electrically insulated independent gold-plating segments. Designing the anti-plating bridge 230 in this shape enhances the mechanical anchoring force of the LPI anti-plating bridge, prevents it from falling off during processing, relaxes the alignment accuracy requirements, and improves process robustness and yield. Furthermore, by significantly increasing the creepage distance, it fundamentally prevents bridging short circuits during electroplating and use, resulting in higher reliability. This method achieves simultaneous improvement in product quality and production efficiency through graphic optimization without increasing additional process costs. Optionally, the transverse shielding portion and the longitudinal anchoring portion are arranged perpendicularly.
[0059] The anti-plating bridge 230 is at least one of the following shapes: "I", "T", and "L". Optionally, as... Figure 4 As shown, in this embodiment, the anti-plating bridge 230 is in the shape of an "I". The current straight-line design of the anti-plating bridge has been optimized into an "I" shape design to increase the adhesion area between the anti-plating bridge and the substrate and improve the adhesion of the anti-plating bridge.
[0060] The thickness of the anti-plating bridge 230 is 15-25 μm, and the thickness of the anti-plating film is 50 μm ± 5 μm. A shunt pad is added to the independent gold-plated segment, i.e., the fingertip. The shunt pad is designed on the periphery of the substrate forming dimensions to facilitate cutting before obtaining the final product. The addition of shunt pads (pads) to the segmented fingertip improves the problem of segmental nodule formation caused by excessive discharge at the independent tips of the fingertip in high-current areas (edge effects).
[0061] Example: A method for gold plating multi-level contacts in a large-format optical module connector, comprising the following steps:
[0062] Step 1: Material preparation: such as Figure 3 As shown, a substrate 200 to be gold-plated is provided. The substrate 200 has a processing surface, which includes a non-gold-plated area 210 and a gold-plated area 220. The gold-plated area 220 has a continuous copper surface to be gold-plated.
[0063] Step 2: Patterning mask: An anti-plating film is provided in the non-gold plating area 210 of the substrate 200, and an anti-plating bridge 230 is formed on the copper surface to be gold plated. The anti-plating bridge 230 divides the continuous copper surface to be gold plated into multiple independent gold plating segments that are electrically insulated from each other, i.e. segmented fingers.
[0064] The anti-plating film and anti-plating bridge 230 are formed in two steps: first, a dry film is applied to the non-gold-plated area 210 of the substrate 200 to form an anti-plating film; then, an LPI ink layer is formed on the copper surface of the substrate 200 to be gold-plated; then, through exposure and development processes, the preset pattern is transferred to the LPI ink layer, thereby simultaneously forming a pattern window that exposes the gold-plated area of the substrate and an anti-plating bridge 230 that divides the continuous copper surface to be gold-plated into multiple independent gold-plating segments.
[0065] Step 3: Pre-treatment for gold plating: The substrate 200 after film application is subjected to pre-treatment such as pickling, high-pressure spraying of 800-mesh diamond abrasive, high-pressure water washing, pickling, micro-etching, high-pressure sandblasting, water washing, and drying to clean and activate the gold plating surface.
[0066] Step 4: First film application: Divide the processing surface of the substrate 200 into a first region and a second region. Apply a composite protective film 100 to the second region, so that the glue-free sealing area 121 is attached to the gold-plating area 220 of the second region, and the adhesive fixing area 111 is attached to the substrate surface surrounding the gold-plating area 220 in the second region.
[0067] Step 5: First lamination: Use a lamination machine to press the substrate 200 with the composite protective film 100 to ensure that the composite protective film 100 is tightly bonded to the surface of the substrate 200, without defects such as bubbles, wrinkles and poor bonding; then open a conductive window on the edge of the board in the first area.
[0068] Step 6: First gold plating: A power supply circuit is established through the conductive skylight, and selective electroplating is performed on the exposed first area to form gold fingers. Then, the composite protective film 100 is removed and the area is washed with water.
[0069] Step 7: Second film application: Apply composite protective film 100 to the first area, so that the glue-free sealing area 121 is attached to the gold-plated area of the first area, and the adhesive fixing area 111 is attached to the surface of the substrate 200 outside the gold-plated area in the first area.
[0070] Step 8: Second lamination: Use a lamination machine to press the substrate 200 with the laminated protective film 100, and then open a conductive window on the edge of the board in the second region;
[0071] Step 9: Second gold plating: A power supply circuit is established through the conductive skylight, and selective electroplating is performed on the exposed second area to form gold fingers. Then, the composite protective film 100 is removed and the area is washed with water.
[0072] Step 10: Post-processing: The gold-plated substrate 200 is further processed to obtain the finished circuit board.
[0073] It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the scope of protection of this application. Therefore, the scope of protection of this patent application shall be determined by the appended claims.
Claims
1. A gold plating method for multi-level contacts in a large-format optical module connector, characterized in that: Includes the following steps: Patterned mask: A substrate (200) to be gold plated is provided, the substrate (200) having a processing surface including a non-gold plated area (210) and a gold plated area (220), the gold plated area (220) having a continuous copper surface to be gold plated, an anti-plating film is provided in the non-gold plated area of the substrate (200), and an anti-plating bridge (230) is formed on the copper surface to be gold plated, the anti-plating bridge (230) dividing the continuous copper surface to be gold plated into multiple independent gold-plated segments that are electrically insulated from each other; Pre-plating treatment: The substrate (200) after film application is pre-treated to clean and activate the gold-plated surface; First film application: The processing surface of the substrate (200) is divided into a first region and a second region. A composite protective film (100) is applied to the second region. The lower surface of the composite protective film (100) includes a glue-free sealing area (121) and an adhesive fixing area (111). The glue-free sealing area (121) is attached to the gold-plating area (220) of the second region, and the adhesive fixing area (111) is attached to the substrate surface outside the gold-plating area in the second region. First lamination: The substrate (200) to which the composite protective film (100) is laminated is laminated using a lamination machine, and then a conductive window is opened on the edge of the board in the first region; First gold plating: A power supply circuit is established through the conductive skylight, and selective electroplating is performed on the exposed first area to form gold fingers. Then the composite protective film (100) is removed and the area is washed with water. Second film application: A composite protective film (100) is applied to the first area, so that the glue-free sealing area (121) is attached to the gold-plated area of the first area, and the adhesive fixing area (111) is attached to the surface of the substrate (200) outside the gold-plated area in the first area. Second lamination: The substrate to which the composite protective film (100) is laminated is laminated using a lamination machine, and then a conductive window is opened on the edge of the board in the second region; Second gold plating: A power supply circuit is established through the conductive skylight, and selective electroplating is performed on the exposed second area to form gold fingers. Then the composite protective film (100) is removed and the area is washed with water. Post-processing: The gold-plated substrate (200) undergoes further processing to obtain the finished circuit board.
2. The gold plating method for multi-level contacts in a large-format optical module connector according to claim 1, characterized in that: The composite protective film (100) includes an isolation layer (120) and two adhesive layers (110). The two adhesive layers (110) are respectively fixed to the two sides of the lower surface of the isolation layer (120). Between the two adhesive layers (110), the exposed area of the lower surface of the isolation layer (120) constitutes the glue-free sealing area (121); the lower surfaces of the two adhesive layers (110) constitute the adhesive fixing area (111).
3. The gold plating method for multi-level contacts in a large-format optical module connector according to claim 2, characterized in that: It also includes a buffer layer (130), which is stacked on the isolation layer (120), and the buffer layer (130) and the adhesive layer (110) are located on opposite sides of the isolation layer (120).
4. The gold plating method for large-format, multi-level contacts of optical module connectors according to claim 3, characterized in that: It also includes a release film layer (140), which is stacked on the buffer layer (130), and the release film layer (140) and the isolation layer (120) are located on opposite sides of the buffer layer (130).
5. The gold plating method for multi-level contacts in a large-format optical module connector according to claim 2, characterized in that: The distance between the two adhesive layers (110) is L1, and the width of the gold-plated area (220) on the substrate (200) is L2, then L1 is greater than L2.
6. The gold plating method for multi-level contacts in large-format optical module connectors according to claim 5, characterized in that: When the composite protective film (100) covers the gold-plating area (220) on the substrate (200), the distance between the adhesive layer (110) and the gold-plating area (220) is L3, where L3 is 2-3 mm.
7. The gold plating method for multi-level contacts in a large-format optical module connector according to claim 4, characterized in that: Each adhesive layer (110) has a width of 6-8 mm, a thickness of 25-35 μm, a buffer layer (130) has a thickness of 1-2 mm, the adhesive layer (110) is a waterproof double-sided tape, the buffer layer (130) is a foamed tape, and the isolation layer (120) is a non-adhesive PE film.
8. The gold plating method for multi-level contacts in a large-format optical module connector according to claim 1, characterized in that: The anti-plating bridge (230) includes a transverse shielding portion (231) and a longitudinal anchoring portion (232) extending from one or both ends of the transverse shielding portion (231) toward the non-plated area; the transverse shielding portion (232) spans and covers the copper conductor of the area to be plated, thereby dividing the continuous copper surface to be plated into multiple independent gold-plated segments that are electrically insulated from each other.
9. The gold plating method for multi-level contacts in a large-format optical module connector according to claim 8, characterized in that: The anti-plating bridge (230) is at least one of the following types: "I", "T" and "L".
10. The gold plating method for multi-level contacts in a large-format optical module connector according to claim 8, characterized in that: The thickness of the anti-plating bridge (230) is 15-25μm, the thickness of the anti-plating film is 50μm±5μm, and a shunt pad is added at the end of the independent gold plating section.