A method for manufacturing a gold finger of a circuit board

Abstract

This invention discloses a method for manufacturing gold fingers on a circuit board, comprising the following steps: depositing a conductive layer on a substrate; etching the conductive layer to form a circuit portion, a plurality of pre-plated gold portions, and conductive wire portions electrically connected to the circuit portion and the pre-plated gold portions respectively; covering the surface of the circuit portion and the conductive wire portions with an anti-plating material; immersing the pre-plated gold portions in a gold-containing electroplating solution; energizing the circuit portion to cause gold in the gold-containing electroplating solution to precipitate and adhere to the pre-plated gold portions to form gold fingers; covering the gold fingers and the circuit portion with a first anti-corrosion material; and corroding the conductive wire portions to remove the conductive wire portions. This design improves the gold plating effect, meets the quality requirements of the circuit board, and has a simple overall process and high production efficiency.

Description

Technical Field

[0001] This invention relates to the technical field of circuit board manufacturing, and in particular to a method for manufacturing gold fingers for circuit boards. Background Technology

[0002] The edges of the circuit board need to be equipped with multiple isolated gold fingers. The method of manufacturing gold fingers is generally to connect the circuit section and each pre-plated gold section to the circuit section and each pre-plated gold section by wires after the circuit section and each pre-plated gold section are set on the substrate. The end of the wire near the pre-plated gold section is connected to the top of the pre-plated gold section. Then the circuit board is immersed in a gold-containing electroplating solution and the circuit board is powered on. The gold in the gold-containing electroplating solution is precipitated and adheres to the pre-plated gold section to form gold fingers. However, because the top of the pre-plated gold section is connected to the wire, gold cannot be plated at this position, resulting in poor gold plating effect and failing to meet the requirements. Summary of the Invention

[0003] This invention aims to at least solve one of the technical problems existing in the prior art. To this end, this invention proposes a method for manufacturing gold fingers for circuit boards, improving the gold plating effect and meeting the quality requirements of circuit boards.

[0004] A method for manufacturing gold fingers on a circuit board according to a first aspect of the present invention includes the following steps: forming a conductive layer on a substrate; etching the conductive layer to form a circuit portion, a plurality of pre-plated gold portions, and conductive wire portions electrically connected to the circuit portion and the pre-plated gold portions respectively; covering the surfaces of the circuit portion and the conductive wire portions with an anti-plating material; immersing the pre-plated gold portions in a gold-containing electroplating solution; energizing the circuit portion to cause gold in the gold-containing electroplating solution to precipitate and adhere to the pre-plated gold portions to form gold fingers; covering the gold fingers and the circuit portion with a first anti-corrosion material; and etching the conductive wire portions to remove the conductive wire portions.

[0005] A method for manufacturing gold fingers of a circuit board according to an embodiment of the present invention has at least the following beneficial effects:

[0006] This invention discloses a method for manufacturing gold fingers on circuit boards. The conductive layer on a substrate is etched to directly form circuit sections, multiple pre-plated gold sections, and conductive sections. The conductive sections are electrically connected to the circuit sections and each pre-plated gold section. Then, an anti-plating material is applied to the surfaces of the circuit sections and the conductive sections. When the pre-plated gold sections are immersed in a gold-containing electroplating solution, the circuit sections are energized to cause gold in the solution to precipitate and adhere to the pre-plated gold sections, forming gold fingers. The conductive sections are then etched away. Because the conductive sections are formed through the etching of the conductive layer, they do not obstruct the gold plating at the ends of the pre-plated gold sections, allowing gold to effectively cover the ends. This design improves the gold plating effect, meets the quality requirements of circuit boards, and features a simple overall process with high production efficiency.

[0007] According to some embodiments of the present invention, the etching of the conductive layer to form a circuit portion, a plurality of pre-plated gold portions, and conductive portions electrically connected to the circuit portion and the pre-plated gold portions respectively includes: dividing the conductive layer into a circuit portion region, a pre-plated gold portion region, a conductive portion region, and an area to be etched by patterning; covering the area to be etched with a first photosensitive material; immersing the conductive layer in an electroplating solution containing a second anti-corrosion material; energizing the conductive layer to cause the second anti-corrosion material in the electroplating solution to precipitate and adhere to the circuit portion region, the pre-plated gold portion region, and the conductive portion region of the conductive layer; exposing and developing the first photosensitive material to remove the first photosensitive material; etching the area to be etched in the conductive layer with an etching solution; and removing the second anti-corrosion material from the conductive layer to form the circuit portion, the pre-plated gold portion, and the conductive portion.

[0008] According to some embodiments of the present invention, between the step of covering the area to be etched with the first photosensitive material and the step of immersing the conductive layer in an electroplating solution containing a second anti-corrosion material, the method further includes: immersing the conductive layer in an electroplating solution containing a conductive material, and energizing the conductive layer so that the conductive material in the electroplating solution containing the conductive material precipitates and adheres to the circuit region, the pre-plated gold region, and the conductor region of the conductive layer, wherein the conductive material is the same material as the conductive layer.

[0009] According to some embodiments of the present invention, the process of covering the surface of the circuit portion and the conductor portion with an anti-gold plating material includes: applying a first anti-gold plating material to the contact position between the pre-gold plating portion and the substrate, wherein one end of the pre-gold plating portion away from the substrate is exposed; and applying a second anti-gold plating material to the surface of the circuit portion and the conductor portion.

[0010] According to some embodiments of the present invention, the first anti-gold plating material is used as a first wet film at the contact position between the pre-plated gold portion and the substrate.

[0011] According to some embodiments of the present invention, the second anti-gold plating material is coated on the surface of the circuit portion and the conductor portion as a first dry film.

[0012] According to some embodiments of the present invention, the step of using a first anti-corrosion material to cover the gold finger portion and the circuit portion, and then etching the conductor portion to remove the conductor portion includes: covering the surface of the gold finger portion and the circuit portion with the first anti-corrosion material; covering the conductor portion with a second photosensitive material; exposing and developing the second photosensitive material to remove it; etching the conductor portion with an etching solution; and removing the first anti-corrosion material.

[0013] According to some embodiments of the present invention, the first anti-corrosion material is applied to the surface of the gold finger portion and the circuit portion as a second dry film.

[0014] According to some embodiments of the present invention, the second photosensitive material covers the conductive portion to serve as a second wet film.

[0015] According to some embodiments of the present invention, the circuit portion includes an inner lead, and at least two conductor portions are electrically connected to the inner lead and the pre-plated gold portion respectively, wherein the distance between the two adjacent conductor portions is greater than or equal to 6 mil.

[0016] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0017] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0018] Figure 1 This is a main flowchart of one embodiment of the gold finger manufacturing method of the present invention;

[0019] Figure 2 This is a flowchart of step S200 of one embodiment of the gold finger manufacturing method of the present invention;

[0020] Figure 3 This is a flowchart of step S500 of one embodiment of the gold finger manufacturing method of the present invention;

[0021] Figure 4 This is a schematic diagram of the circuit board structure in step S300;

[0022] Figure 5 This is a schematic diagram of the circuit board in step S500.

[0023] Figure label:

[0024] Substrate 100; conductive layer 200; circuit section 210; pre-plated gold section 220; wire section 230; gold finger section 240; first dry film 300; first wet film 400; second dry film 500; second wet film 600. Detailed Implementation

[0025] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0026] In the description of this invention, it should be understood that the orientation descriptions, such as the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer", indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0027] In the description of this invention, "several" means one or more, "more than" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0028] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0029] like Figure 1 As shown, a method for manufacturing gold fingers of a circuit board according to a first aspect embodiment of the present invention includes the following steps:

[0030] S100, A conductive layer 200 is disposed on the substrate 100;

[0031] S200, the conductive layer 200 is etched to form a circuit portion 210, a plurality of pre-plated gold portions 220, and a wire portion 230 that is electrically connected to the circuit portion 210 and the pre-plated gold portions 220 respectively.

[0032] S300: An anti-gold plating material is used to cover the surfaces of the circuit section 210 and the conductor section 230;

[0033] S400: The pre-plated gold portion 220 is immersed in a gold-containing electroplating solution, and the circuit portion 210 is energized so that gold in the gold-containing electroplating solution is deposited and adhered to the pre-plated gold portion 220 to form a gold finger portion 240.

[0034] S500: The gold finger portion 240 and the circuit portion 210 are covered with a first anti-corrosion material, and the conductor portion 230 is corroded to remove the conductor portion 230.

[0035] The substrate 100 can be an aluminum substrate 100 or a ceramic substrate 100. The substrate 100 can be formed by steps such as blanking, automatic optical inspection, browning, pressing, and milling. The conductive layer 200 can be made of copper. The conductive layer 200 can be formed on the surface of the substrate 100 and on the inner sidewall of the through hole of the substrate 100 through a copper plating step.

[0036] It should be noted that the above steps can be used to process large-area boards with multiple circuit board units. The boards can then be cut to form individual circuit boards.

[0037] The present invention discloses a method for manufacturing gold fingers on a circuit board. A conductive layer 200 on a substrate 100 is etched to directly form a circuit portion 210, multiple pre-plated gold portions 220, and a conductive portion 230. The conductive portions 230 are electrically connected to the circuit portion 210 and each pre-plated gold portion 220. Then, an anti-plating material is applied to the surfaces of the circuit portion 210 and the conductive portions 230. When the pre-plated gold portions 220 are immersed in a gold-containing electroplating solution, the circuit portion 210 is energized to cause gold in the gold-containing electroplating solution to precipitate and adhere to the pre-plated gold portions 220 to form gold fingers 240. The conductive portions 230 are then etched away. Because the conductive portions 230 are formed by etching the conductive layer 200, they do not obstruct the gold plating at the ends of the pre-plated gold portions 220, allowing gold to effectively cover the ends of the pre-plated gold portions 220. This design improves the gold plating effect, meets the quality requirements of the circuit board, and has a simple overall process and high production efficiency.

[0038] Additionally, it should be noted that the circuit section 210 generally includes various types of conductor segments. Before etching the conductive layer 200, the operator needs to design the pattern of the conductive layer 200, and then etch the parts to be etched to form the circuit section 210 with the corresponding pattern. Specifically, the operator needs to pay attention to the following points when designing for different types of conductor segments. For example, the circuit section 210 includes signal connection lines, which refer to impedance lines. It is not allowed to directly connect the conductor section 230 to the signal connection lines. Instead, the conductor section 230 must be connected to the signal connection lines. The end pad of the line connects to the conductor portion 230, and the conductor portion 230 is flush with the end pad of the signal connection line. The circuit portion 210 includes a non-signal connection line, which refers to a non-impedance line connected to the gold finger portion 240. Here, the lead extends from the through-hole of the circuit board. The circuit portion 210 includes an inner lead, which means that in the circuit portion 210, in addition to the two types of conductor segments mentioned above, at least two conductor portions 230 are electrically connected to the inner lead and the pre-plated gold portion 220 respectively. The spacing between two adjacent conductor portions 230 is greater than or equal to 6 mil. When designing, if the spacing between two conductor portions 230 is less than 6 mil, it is necessary to prioritize finding a position in the pattern with a spacing ≥ 6 mil to lead out the conductor portion 230.

[0039] In some embodiments of the present invention, such as Figure 2 As shown, the process in S200, which involves etching the conductive layer 200 to form a circuit portion 210, a plurality of pre-plated gold portions 220, and a wire portion 230 that is electrically connected to the circuit portion 210 and the pre-plated gold portions 220 respectively, includes:

[0040] S210. In the conductive layer 200, the circuit section 210 area, the pre-plated gold section 220 area, the conductor section 230 area and the area to be etched are divided by pattern making.

[0041] S220. Cover the area to be etched with a first photosensitive material;

[0042] S240. The conductive layer 200 is immersed in an electroplating solution containing a second anti-corrosion material, and an electric current is applied to the conductive layer 200 so that the second anti-corrosion material in the electroplating solution containing the second anti-corrosion material is deposited and attached to the circuit portion 210 region, the pre-plated gold portion 220 region, and the wire portion 230 region of the conductive layer 200.

[0043] S250, Expose the first photosensitive material and perform development treatment to remove the first photosensitive material;

[0044] S260. Use an etchant to etch the area to be etched in the conductive layer 200;

[0045] S270, the second anti-corrosion material is removed from the conductive layer 200 to form the circuit section 210, the pre-plated gold section 220, and the conductor section 230.

[0046] In S210, after the staff designs the circuit pattern, they can use graphic production techniques such as silkscreen printing to divide the conductive layer 200 into the circuit section 210 area, the pre-plated gold section 220 area, the conductor section 230 area, and the area to be etched.

[0047] By covering the area to be etched with a first photosensitive material to form a barrier, the conductive layer 200 is immersed in an electroplating solution. Using the conductive layer 200 as one of its electrodes, an electric current is applied to the conductive layer 200, and a second anti-corrosion material is deposited and attached to the circuit portion 210 area, the pre-plated gold portion 220 area, and the wire portion 230 area of ​​the conductive layer 200. At the same time, the second anti-corrosion material does not cover the area to be etched. The second anti-corrosion material can be tin.

[0048] Then, in S250, the area to be etched is marked by exposing and developing the first photosensitive material, and the film formed by the first photosensitive material is removed. Then, in S260, the area to be etched of the conductive layer 200 is etched using an etching solution. Specifically, the etching solution can be selected according to the actual situation. Based on the selection of the above materials, a solution that can etch copper but not tin can be selected. Finally, the conductive layer 200 is treated to remove the second anti-corrosion material, thereby forming the circuit section 210, the pre-plated gold section 220, and the conductor section 230. Specifically, when the second anti-corrosion material is tin, a solution that can remove tin can be used to soak and remove the tin on the conductive layer 200. This design can quickly form the circuit section 210, the pre-plated gold section 220, and the conductor section 230, improving production efficiency and shortening manufacturing time.

[0049] In some embodiments of the present invention, such as Figure 2 As shown, between S220, covering the area to be etched with the first photosensitive material, and S240, immersing the conductive layer 200 in an electroplating solution containing the second anti-corrosion material, the following steps are also included:

[0050] S230. The conductive layer 200 is immersed in an electroplating solution containing conductive material, and an electric current is applied to the conductive layer 200 so that the conductive material in the electroplating solution containing conductive material is deposited and attached to the circuit portion 210 region, the pre-plated gold portion 220 region, and the wire portion 230 region of the conductive layer 200, wherein the conductive material is the same material as the conductive layer 200.

[0051] In step S100, a conductive layer 200 of a predetermined thickness can be first fabricated on the substrate 100. In subsequent steps, in step S220, the area to be etched is first covered with a first photosensitive material. Then, the conductive layer 200 is immersed in an electroplating solution containing a conductive material. When the conductive layer 200 is energized, the conductive material in the electroplating solution precipitates and adheres to the circuit portion 210 area, the pre-plated gold portion 220 area, and the wire portion 230 area of ​​the conductive layer 200, thereby thickening the conductive layer 200 in that area to a suitable thickness. For example, when the material of the conductive layer 200 is copper, a copper-containing electroplating solution is used for electroplating. Therefore, since the conductive layer 200 in the area to be etched needs to be etched, a thicker conductive layer 200 is not required in step S100, saving costs and improving the etching efficiency.

[0052] In some embodiments of the present invention, such as Figure 4 As shown, in S300, the surface of the circuit section 210 and the conductor section 230 covered with an anti-gold plating material includes:

[0053] The first anti-gold plating material is applied to the contact position between the pre-gold plating part 220 and the substrate 100, wherein the end of the pre-gold plating part 220 facing away from the substrate 100 is exposed.

[0054] The second anti-gold plating material is applied to the surface of the circuit section 210 and the conductor section 230.

[0055] First, a first anti-gold plating material is applied to the contact area between the pre-plated gold portion 220 and the substrate 100, so that gold is less likely to leak into the contact area between the pre-plated gold portion 220 and the substrate 100 during the subsequent gold plating process, thereby reducing the risk of short circuit caused by contact between the gold plating layers on two adjacent pre-plated gold portions 220.

[0056] The second anti-gold plating material is applied to the surface of the circuit section 210 and the conductor section 230 to prevent gold from covering the surface of the circuit section 210 and the conductor section 230.

[0057] In some embodiments of the present invention, the first anti-gold plating material is used as a first wet film 400 at the contact position between the pre-gold plating portion 220 and the substrate 100. The first wet film 400 can better cover the relatively uneven position, thereby better covering the contact position between the pre-gold plating portion 220 and the substrate 100. Specifically, the first anti-gold plating material can be selected from conventional anti-gold plating inks.

[0058] In some embodiments of the present invention, a second anti-gold plating material is coated on the surface of the circuit portion 210 and the conductor portion 230 to serve as a first dry film 300. The second anti-gold plating material can be selected from conventional dry film sheets. The first dry film 300 has stable anti-gold plating performance, is easy to operate, and can keep the surface of the circuit portion 210 and the conductor portion 230 clean.

[0059] Specifically, after gold plating, the first dry film 300 can be removed.

[0060] In some embodiments of the present invention, such as Figure 3 , 5 As shown, in S500, the gold finger portion 240 and the circuit portion 210 are covered with a first anti-corrosion material, and the conductor portion 230 is etched to remove the conductor portion 230, including:

[0061] S510. The first anti-corrosion material is applied to the surface of the gold finger portion 240 and the circuit portion 210.

[0062] S520, Cover the conductor portion 230 with the second photosensitive material;

[0063] S530, Expose the second photosensitive material and perform development treatment to remove the second photosensitive material;

[0064] S540, Corrode the conductor section 230 using an etching solution;

[0065] S550, Remove the first anti-corrosion material.

[0066] Here, after covering the surface of the gold finger portion 240 and the circuit portion 210 with the first anti-corrosion material, the wire portion 230 is covered with the second photosensitive material. The second photosensitive material is exposed and developed to mark the wire portion 230. The second photosensitive material is then removed so that the position of the wire portion 230 can be clearly known by the workers during the manufacturing process. The wire portion 230 is then etched with an etching solution to determine the corrosion status of the wire portion 230, so that the wire portion 230 can be removed effectively, preventing short circuit between the circuit portion 210 and the gold finger portion 240.

[0067] In some embodiments of the present invention, a first anti-corrosion material is applied to the surface of the gold finger portion 240 and the circuit portion 210 as a second dry film 500. The first anti-corrosion material can be selected from conventional dry film sheets. The second dry film 500 has stable anti-corrosion performance, is easy to operate, and can keep the surface of the gold finger portion 240 and the circuit portion 210 clean.

[0068] In some embodiments of the present invention, a second photosensitive material is applied to the conductive portion 230 as a second wet film 600. The second photosensitive material can be selected from conventional anti-gold plating inks. After exposure and development, the conductive portion 230 can be marked and removed, making the operation simple and convenient.

[0069] In addition, an acidic etchant can be used to etch the conductor section 230. After S500, the second dry film 500 also needs to be removed.

[0070] Then, the performance of the pre-formed circuit board needs to be tested. Wet green oil for insulation is coated on the surface of the circuit board. Then, impedance testing is performed on the circuit section 210 and the gold finger section 240. Then, characters are printed on the surface of the substrate 100. A dry film is formed in the position outside the characters using film. Immersion gold treatment is performed to form characters. Then, the dry film formed by film is removed.

[0071] Finally, each circuit board unit in the entire board is cut out, the outer edge is shaped and beveled, and ET exploratory testing and operation testing are carried out. If the quality is qualified, it is packaged.

[0072] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0073] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A method of manufacturing a gold finger of a circuit board, characterized by, The method comprises the following steps: providing a conductive layer on a substrate; etching the conductive layer to form a circuit portion, a plurality of pre-gold plated portions, and a wire portion electrically connected to the circuit portion and the pre-gold plated portions respectively; covering the surface of the circuit portion and the wire portion with an anti-gold plating material; immersing the pre-gold plated portions in a gold-containing plating solution, and applying current to the circuit portion to cause gold in the gold-containing plating solution to precipitate and adhere to the pre-gold plated portions to form gold finger portions; covering the gold finger portions and the circuit portion with a first anti-corrosion material, and etching the wire portion to remove the wire portion; the etching of the conductive layer to form the circuit portion, the plurality of pre-gold plated portions, and the wire portion electrically connected to the circuit portion and the pre-gold plated portions respectively comprises: dividing the circuit portion region, the pre-gold plated portion region, the wire portion region, and the etching region in the conductive layer by pattern making; covering the etching region with a first photosensitive material; immersing the conductive layer in a plating solution containing a second anti-corrosion material, and applying current to the conductive layer to cause the second anti-corrosion material in the plating solution containing the second anti-corrosion material to precipitate and adhere to the circuit portion region, the pre-gold plated portion region, and the wire portion region of the conductive layer; exposing and developing the first photosensitive material to remove the first photosensitive material; etching the etching region of the conductive layer with an etching solution; removing the second anti-corrosion material from the conductive layer to form the circuit portion, the pre-gold plated portions, and the wire portion; between the covering of the etching region with the first photosensitive material and the immersing of the conductive layer in the plating solution containing the second anti-corrosion material, further comprising: immersing the conductive layer in a plating solution containing a conductive material, and applying current to the conductive layer to cause the conductive material in the plating solution containing the conductive material to precipitate and adhere to the circuit portion region, the pre-gold plated portion region, and the wire portion region of the conductive layer, wherein the conductive material is the same material as the conductive layer; the covering of the surface of the circuit portion and the wire portion with the anti-gold plating material comprises: applying a first anti-gold plating material to the contact position of the pre-gold plated portion and the substrate, wherein one end of the pre-gold plated portion away from the substrate is exposed; applying a second anti-gold plating material to the surface of the circuit portion and the wire portion; the first anti-gold plating material at the contact position of the pre-gold plated portion and the substrate is a first wet film; the second anti-gold plating material applied to the surface of the circuit portion and the wire portion is a first dry film.

2. The method of claim 1, wherein the covering of the gold finger portions and the circuit portion with the first anti-corrosion material, and the etching of the wire portion to remove the wire portion comprises: covering the surface of the gold finger portions and the circuit portion with the first anti-corrosion material; covering the wire portion with a second photosensitive material; exposing and developing the second photosensitive material to remove the second photosensitive material; etching the wire portion with an etching solution; removing the first anti-corrosion material.

3. The method of claim 2, wherein the gold fingers are formed by a process comprising: the first anti-corrosion material on the surface of the gold finger portions and the circuit portion is a second dry film.

4. The method of claim 2, wherein the gold fingers are formed by a process comprising: the second photosensitive material covering the wire portion is a second wet film.

5. The method of claim 1, wherein The circuit portion includes an inner lead, at least two wire portions are respectively electrically connected with the inner lead and the pre-gold portion, and the distance between two adjacent wire portions is greater than or equal to 6 mils.

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