Manufacturing method of gold-plated PCB (Printed Circuit Board) and gold-plated PCB manufactured by same

Abstract

According to the invention, through two times of film coating, the copper plating layer, the nickel plating layer and the gold plating layer can be selectively and only electroplated on the periphery of the via hole and the bonding pad for the single-sided PCB and the double-sided PCB. When the manufactured PCB is a single-sided board, the via hole and the bonding pad are sequentially provided with a copper plating layer, a nickel plating layer and a gold plating layer, and the copper plating layer at the via hole wraps the bottom copper layer at the periphery of the via hole; when the manufactured PCB is a double-sided board, the hole wall of the via hole is provided with a conductive film, the conductive film enables the bottom copper layers on the two sides of the periphery of the via hole to be communicated, the via hole is provided with a copper plating layer, the copper plating layer wraps the conductive film and the bottom copper layers on the periphery of the via hole, a nickel plating layer and a gold plating layer are sequentially arranged outside the copper plating layer, and the copper plating layer, the nickel plating layer and the gold plating layer are sequentially arranged on the bonding pad. And the rest areas of the PCB except the peripheries of the via holes and the bonding pads are coated with solder resist ink layers. According to the invention, surface electroplating treatment is omitted in wiring connection, and rough estimation is carried out, so that about 55% of precious metal can be saved when the PCB is manufactured by using the method provided by the invention.

Description

Technical Field

[0001] The invention belongs to the technical field of PCB board manufacturing, and particularly relates to a manufacturing method of a gold-plated PCB board and the manufactured gold-plated PCB board. Background Art

[0002] Currently in the LED industry (including all PCB manufacturing industries), the surface of the circuit board needs to be electroplated, and the thickness of the gold-plated layer must be more than 0.3 micro-inches to meet the requirements of ultrasonic bonding before packaging and welding process during SMT. However, the price of gold in the market has repeatedly increased, causing the production cost of gold-plated circuit boards to rise accordingly. The gold price and processing cost of gold-plated circuit boards per square meter is more than 400 yuan.

[0003] In the prior art, when manufacturing PCB boards, only one lamination is usually performed, and surface electroplating treatment is performed on the periphery of the vias, the pads and the connecting traces, and then the redundant bottom copper layer is etched. The purpose of the surface electroplating treatment is to prevent the nickel-plated layer of the pads from being oxidized, which affects the solid crystal and wire bonding. As for the connecting traces, they only need to be coated with solder mask ink for protection, and no corrosion can meet the use requirements. In addition, the area of ​​the connecting traces is usually large, and more precious metals need to be consumed during the surface electroplating treatment. Based on this, the inventor of the present application has improved the existing method for manufacturing PCB boards. Through two laminations, for single-sided PCB boards and double-sided PCB boards, copper-plated layers, nickel-plated layers and gold-plated layers can be selectively plated only on the periphery of the vias and the pads. The present invention omits the surface electroplating treatment on the connecting traces. According to a rough estimate, the PCB boards manufactured by the present invention can save about 55% of the amount of precious metals. Summary of the invention

[0004] The present invention mainly solves the technical problems existing in the prior art and provides a method for manufacturing a gold-plated PCB board and the gold-plated PCB board manufactured by the method.

[0005] The above technical problems of the present invention are mainly solved by the following technical solutions: a method for manufacturing a gold-plated PCB board, when the PCB board is a single-sided board, the body of the PCB board is composed of a substrate layer and a bottom copper layer on one side, and the manufacturing method comprises the following steps: (1) drilling vias on the body according to the circuit design, and determining the positions of the pads and the connection lines between the vias, between the pads, or between the vias and the pads; (2) laminating for the first time, and then exposing and developing the vias so that the periphery of the vias and the pads are exposed, and the remaining bottom copper layers are covered and protected; (3) simultaneously laminating the vias and the pads according to the The first step is to electroplate copper, nickel and gold layers, wherein the copper layer at the via covers the bottom copper layer around the via; (4) remove the first coating and clean the PCB board; (5) coat the second coating, and then expose and develop the connection lines to cover and protect them, and expose the remaining bottom copper layer; (6) etch the exposed bottom copper layer, and the remaining bottom copper layer is the connection line; (7) remove the second coating and clean the PCB board; (8) perform automatic optical inspection and electrical inspection on the PCB board; (9) apply a solder mask ink layer to the qualified PCB board, and the solder mask ink layer covers the area around the via and the rest of the area outside the pad. When the PCB board is a double-sided board, the body of the PCB board is composed of a substrate layer and bottom copper layers on both sides. The manufacturing method includes the following steps: (1) drilling vias on the body according to the circuit design, and determining the positions of the pads and the connection lines between the vias, between the pads, or between the vias and the pads; (2) depositing a layer of conductive film on the inner wall of the via, the conductive film connecting the bottom copper layers on both sides of the via circumference; (3) laminating for the first time, and then exposing and developing the via circumference and pads to expose the via circumference and cover the remaining bottom copper layers; (4) electroplating copper on the vias and pads at the same time. ⑸ Remove the first coating and clean the PCB board; ⑹ Apply the second coating, and then expose and develop the connection traces to cover and protect them, and expose the remaining bottom copper layer; ⑺ Etch the exposed bottom copper layer, and the remaining bottom copper layer is the connection trace; ⑻ Remove the second coating and clean the PCB board; ⑼ Perform automatic optical inspection and electrical inspection on the PCB board; ⑽ Apply a solder mask ink layer to the qualified PCB board, and the solder mask ink layer covers the remaining area around the via and the pad.

[0006] Preferably, when the PCB board is a single-sided board, the thickness of the copper plating layer in step (3) is 4-6 microns, the thickness of the nickel plating layer is 4-6 microns, and the thickness of the gold plating layer is 0.2-0.8 microinches; when the PCB board is a double-sided board, the thickness of the copper plating layer in step (4) is 4-6 microns, the thickness of the nickel plating layer is 4-6 microns, and the thickness of the gold plating layer is 0.2-0.8 microinches.

[0007] Preferably, when the PCB board is a double-sided board, the conductive film in step (2) is a polymer organic conductive film with a thickness of 0.05-0.14 microns, or is copper plating with a thickness of 0.6-1.0 microns.

[0008] The PCB board manufactured by the above manufacturing method comprises a plurality of vias, pads and connecting traces between the vias, between the pads or between the vias and the pads. When the PCB board is a single-sided board, a copper-plated layer, a nickel-plated layer and a gold-plated layer are sequentially provided on the vias and the pads, wherein the copper-plated layer at the vias covers the bottom copper layer around the vias, and the remaining areas on the PCB board except the vias and the pads are coated with a solder resist ink layer; when the PCB board is a double-sided board, a conductive film is provided on the hole wall of the vias, the conductive film connects the bottom copper layers on both sides of the vias, a copper-plated layer is provided on the vias, the copper-plated layer covers the conductive film and the bottom copper layer around the vias, a nickel-plated layer and a gold-plated layer are sequentially provided outside the copper-plated layer, a copper-plated layer, a nickel-plated layer and a gold-plated layer are sequentially provided on the pads, and the remaining areas on the PCB board except the vias and the pads are coated with a solder resist ink layer.

[0009] Preferably, the copper-plated layer has a thickness of 4-6 microns, the nickel-plated layer has a thickness of 4-6 microns, the gold-plated layer has a thickness of 0.2-0.8 microinches, and the conductive film is a polymer organic conductive film with a thickness of 0.05-0.14 microns, or is copper plating with a thickness of 0.6-1.0 microns.

[0010] The present invention improves the existing PCB manufacturing method. Through two laminations, copper plating, nickel plating and gold plating can be selectively plated only on the via holes and pads for single-sided PCBs and double-sided PCBs. The present invention eliminates the need for surface plating on the connection lines. According to a rough estimate, the PCB manufacturing method can save about 55% of the amount of precious metals. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a structural schematic diagram of a single-sided PCB board body in the prior art;

[0012] Figure 2 yes Figure 1 A schematic diagram of a cross-sectional structure;

[0013] Figure 3 This is a schematic diagram of the structure of a single-sided PCB board after the first lamination, exposure, development and electroplating of the present invention;

[0014] Figure 4 yes Figure 3 A schematic diagram of a cross-sectional structure;

[0015] Figure 5 yes Figure 4 A structural schematic diagram of the enlarged portion A in the middle;

[0016] Figure 6 yes Figure 4 A schematic diagram of a structure enlarged in the middle B part;

[0017] Figure 7 This is a schematic diagram of the structure of a single-sided PCB board after the second lamination and exposure and development of the present invention;

[0018] Figure 8 yes Figure 7 A schematic diagram of a cross-sectional structure;

[0019] Fig. 9 This is a schematic diagram of the structure of a single-sided PCB board after etching and film stripping of the present invention;

[0020] Fig.10 yes Fig. 9 A schematic diagram of a cross-sectional structure;

[0021] Fig.11 This is a structural schematic diagram of a single-sided PCB board after being coated with solder resist ink;

[0022] Fig.12 yes Fig.11 A schematic diagram of a cross-sectional structure;

[0023] Fig.13 It is a structural schematic diagram of a double-sided PCB board body in the prior art;

[0024] Fig.14 yes Fig.13 A schematic diagram of a cross-sectional structure;

[0025] Fig.15 It is a structural schematic diagram of a double-sided PCB board of the present invention after the first lamination, exposure, development and electroplating;

[0026] Fig.16 yes Fig.15 A schematic diagram of a cross-sectional structure;

[0027] Fig.17 yes Fig.16 A schematic diagram of a structure enlarged in the middle C part;

[0028] Fig.18 yes Fig.16 A schematic diagram of a structure enlarged in the middle D part;

[0029] Fig.19 This is a structural schematic diagram of a double-sided PCB board of the present invention after second lamination and exposure and development;

[0030] Fig. 20 yes Fig.19 A schematic diagram of a cross-sectional structure;

[0031] Fig.21 This is a schematic diagram of the structure of the double-sided PCB board after etching and film stripping of the present invention;

[0032] Fig. 22 yes Fig.21 A schematic diagram of a cross-sectional structure;

[0033] Fig.23 This is a structural schematic diagram of a double-sided PCB board after being coated with solder resist ink according to the present invention;

[0034] Fig.24 yes Fig.23 A schematic diagram of a cross-sectional structure.

[0035] In the figure, 1-body, 2-bottom copper layer, 3-substrate layer, 4-pad, 5-via, 6-connecting trace, 7-first coating, 8-conductive film, 9-copper plating layer, 10-nickel plating layer, 11-gold plating layer, 12-second coating, 13-solder mask ink layer. DETAILED DESCRIPTION

[0036] The technical solution of the present invention is further specifically described below through embodiments and in conjunction with the accompanying drawings.

[0037] Embodiment 1: The PCB board of the present invention is a single-sided board, see Figure 1 and Figure 2 The main body of the PCB board is composed of a substrate layer and a single-sided bottom copper layer. Figure 3-Figure 12 , at this time, the manufacturing method of the present invention includes the following steps: (1) drilling vias on the body according to the circuit design, and determining the positions of the pads and the connecting wires between the vias, between the pads or between the vias and the pads; (2) laminating for the first time, and then exposing and developing to expose the periphery of the vias and the pads, and covering and protecting the remaining bottom copper layers; (3) electroplating a copper plating layer, a nickel plating layer and a gold plating layer on the vias and the pads in sequence, wherein the copper plating layer at the vias covers the bottom copper layer around the vias; (4) removing the first laminating, and cleaning the PCB board; (5) laminating for the second time, and then exposing and developing to cover and protect the connecting wires, and exposing the remaining bottom copper layers; (6) etching the exposed bottom copper layer, and the remaining bottom copper layer is the connecting wire; (7) removing the second laminating, and cleaning the PCB board; (8) performing automatic optical inspection and electrical inspection on the PCB board; (9) coating a solder resist ink layer on the qualified PCB board, and the solder resist ink layer covers the periphery of the vias and the remaining areas outside the pads. Wherein, the thickness of the copper plating layer in step (3) is 4-6 microns, the thickness of the nickel plating layer is 4-6 microns, and the thickness of the gold plating layer is 0.2-0.8 micro-inches.

[0038] See also Figure 11-Figure 12The PCB board made by the present invention includes a plurality of vias, pads, and connecting traces between the vias, between the pads, or between the vias and the pads. The vias and the pads are provided with a copper plating layer, a nickel plating layer, and a gold plating layer in sequence, wherein the copper plating layer at the vias covers the bottom copper layer around the vias, and the remaining areas of the PCB board except the vias and the pads are coated with a solder resist ink layer, wherein the thickness of the copper plating layer is 4-6 microns, the thickness of the nickel plating layer is 4-6 microns, and the thickness of the gold plating layer is 0.2-0.8 microinches.

[0039] The present invention improves the existing PCB manufacturing method. Through two laminations, for a single-sided PCB, a copper plating layer, a nickel plating layer and a gold plating layer can be selectively plated only on the via hole periphery and the pad. The present invention saves the surface plating treatment on the connection line. According to a rough estimate, the PCB manufactured by the present invention can save about 55% of the precious metal usage.

[0040] Embodiment 2: The PCB board of the present invention is a double-sided board, see Fig.13 and Fig.14 The main body of the PCB board is composed of the base material layer and the bottom copper layers on both sides. Figure 15-Figure 24 , at this time, the manufacturing method of the present invention includes the following steps: (1) drilling a via hole on the body according to the circuit design, and determining the position of the pad and the connection wiring between the via holes, between the pads, or between the via hole and the pad; (2) depositing a layer of conductive film on the inner wall of the via hole, and the conductive film connects the bottom copper layer on both sides of the via hole circle; (3) laminating for the first time, and then exposing and developing the via hole circle and the pad to expose, and covering and protecting the remaining bottom copper layer; (4) electroplating a copper plating layer, a nickel plating layer and a gold plating layer on the via hole and the pad at the same time, wherein the via hole The copper-plated layer at the point covers the conductive film and the bottom copper layer around the via hole; (5) remove the first coating and clean the PCB board; (6) coat the second coating, and then expose and develop the connection lines to cover and protect them, and expose the remaining bottom copper layer; (7) etch the exposed bottom copper layer, and the remaining bottom copper layer is the connection line; (8) remove the second coating and clean the PCB board; (9) perform automatic optical inspection and electrical inspection on the PCB board; (10) apply a solder mask ink layer to the qualified PCB board, and the solder mask ink layer covers the remaining area around the via hole and the pad. Among them, the conductive film in step (2) is a polymer organic conductive film with a thickness of 0.05-0.14 microns, or a copper deposition film with a thickness of 0.6-1.0 microns; the copper plating layer in step (4) has a thickness of 4-6 microns, the nickel plating layer has a thickness of 4-6 microns, and the gold plating layer has a thickness of 0.2-0.8 micro-inches.

[0041] See also Figure 23-Figure 24The PCB board made by the present invention includes a plurality of vias, pads, and connecting wires between vias, pads, or vias and pads. A conductive film is provided on the hole wall of the via, and the conductive film connects the bottom copper layer on both sides of the via circumference. A copper-plated layer is provided on the via, and the copper-plated layer covers the conductive film and the bottom copper layer around the via. A nickel-plated layer and a gold-plated layer are provided on the outside of the copper-plated layer in sequence. A copper-plated layer, a nickel-plated layer, and a gold-plated layer are provided on the pad in sequence. The rest of the area on the PCB board except the via circumference and pads is coated with a solder resist ink layer. The conductive film is a polymer organic conductive film with a thickness of 0.05-0.14 microns, or a copper deposition film with a thickness of 0.6-1.0 microns; the thickness of the copper-plated layer is 4-6 microns, the thickness of the nickel-plated layer is 4-6 microns, and the thickness of the gold-plated layer is 0.2-0.8 micro-inches.

[0042] The present invention improves the existing PCB manufacturing method. Through two laminations, for a double-sided PCB, a copper plating layer, a nickel plating layer and a gold plating layer can be selectively plated only on the via hole periphery and the pad. The present invention saves the surface plating treatment on the connection line. According to a rough estimate, the PCB manufactured by the present invention can save about 55% of the precious metal usage.

[0043] Finally, it should be pointed out that the above embodiments are only representative examples of the present invention. Obviously, the technical solution of the present invention is not limited to the above embodiments, and there are many variations, such as application in the manufacture of multi-layer PCB boards. All variations that can be directly derived or associated with the content disclosed by ordinary technicians in this field should be considered as the protection scope of the present invention.

Claims

1. A method for manufacturing a gold-plated PCB board, characterized in that: When the PCB board is a single-sided board, the body of the PCB board is composed of a substrate layer and a bottom copper layer on one side. The manufacturing method includes the following steps: (1) drilling vias on the body according to the circuit design, and determining the positions of the pads and the connection lines between the vias, between the pads, or between the vias and the pads; (2) laminating for the first time, and then exposing and developing the vias to expose the periphery of the vias and the pads, and covering and protecting the remaining bottom copper layers; (3) electroplating a copper plating layer, a nickel plating layer, and a gold plating layer on the vias and the pads in sequence, wherein the vias are The copper-plated layer covers the bottom copper layer around the via hole; (4) remove the first coating and clean the PCB board; (5) coat the second coating, and then expose and develop it to cover and protect the connection traces, and expose the remaining bottom copper layer; (6) etch the exposed bottom copper layer, and the remaining bottom copper layer is the connection trace; (7) remove the second coating and clean the PCB board; (8) perform automatic optical inspection and electrical inspection on the PCB board; (9) apply a solder mask ink layer to the qualified PCB board, and the solder mask ink layer covers the remaining area around the via hole and the pad; When the PCB board is a double-sided board, the body of the PCB board is composed of a substrate layer and bottom copper layers on both sides. The manufacturing method includes the following steps: (1) drilling vias on the body according to the circuit design, and determining the positions of the pads and the connection lines between the vias, between the pads, or between the vias and the pads; (2) depositing a layer of conductive film on the inner wall of the via, the conductive film connecting the bottom copper layers on both sides of the via circumference; (3) laminating for the first time, and then exposing and developing the via circumference and pads to expose the via circumference and cover the remaining bottom copper layers; (4) electroplating copper on the vias and pads at the same time and in sequence ⑸ Remove the first coating and clean the PCB board; ⑹ Apply the second coating, and then expose and develop the connection traces to cover and protect them, and expose the remaining bottom copper layer; ⑺ Etch the exposed bottom copper layer, and the remaining bottom copper layer is the connection trace; ⑻ Remove the second coating and clean the PCB board; ⑼ Perform automatic optical inspection and electrical inspection on the PCB board; ⑽ Apply a solder mask ink layer to the qualified PCB board, and the solder mask ink layer covers the area around the via and the rest of the area outside the pad.

2. The method for making a gold-plated PCB according to claim 1, characterized in that: When the PCB board is a single-sided board, the thickness of the copper plating layer in step (3) is 4-6 microns, the thickness of the nickel plating layer is 4-6 microns, and the thickness of the gold plating layer is 0.2-0.8 microinches; when the PCB board is a double-sided board, the thickness of the copper plating layer in step (4) is 4-6 microns, the thickness of the nickel plating layer is 4-6 microns, and the thickness of the gold plating layer is 0.2-0.8 microinches.

3. A method for manufacturing a gold-plated PCB board according to claim 1 or 2, characterized in that: When the PCB board is a double-sided board, the conductive film in step (2) is a polymer organic conductive film with a thickness of 0.05-0.14 microns, or is copper plating with a thickness of 0.6-1.0 microns.

4. A PCB board manufactured by the manufacturing method according to any one of claims 1 to 3, comprising a plurality of vias, pads, and connecting traces between vias, between pads, or between vias and pads, characterized in that: When the PCB board is a single-sided board, a copper-plated layer, a nickel-plated layer and a gold-plated layer are sequentially provided on the via hole and the pad, wherein the copper-plated layer at the via hole covers the bottom copper layer around the via hole, and the remaining areas on the PCB board except the via hole and the pad are coated with a solder resist ink layer; when the PCB board is a double-sided board, a conductive film is provided on the hole wall of the via hole, the conductive film connects the bottom copper layer on both sides of the via hole, a copper-plated layer is provided on the via hole, the copper-plated layer covers the conductive film and the bottom copper layer around the via hole, a nickel-plated layer and a gold-plated layer are sequentially provided on the outside of the copper-plated layer, a copper-plated layer, a nickel-plated layer and a gold-plated layer are sequentially provided on the pad, and the remaining areas on the PCB board except the via hole and the pad are coated with a solder resist ink layer.

5. The PCB board according to claim 4, characterized in that The thickness of the copper-plated layer is 4-6 microns, the thickness of the nickel-plated layer is 4-6 microns, the thickness of the gold-plated layer is 0.2-0.8 micro-inches, and the conductive film is a polymer organic conductive film with a thickness of 0.05-0.14 microns, or is copper plating with a thickness of 0.6-1.0 microns.

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