A PCB production process with lead electroplating inside the board

Abstract

The present invention discloses a PCB production process for electroplating leads in the board. The production process includes the following steps: (1) transferring the circuit pattern to the board after drilling, electroplating through holes and board electrification through electroplating film, wherein the space of the unit circuit pattern closest to the edge of the board is sufficient to add a lead extending to the edge of the board, and the lead connected to the unit circuit pattern closest to the area where electroplating is required and with sufficient space is added in the area where electroplating is required; then the pattern is electroplated, film stripped, and etched to complete the engraving of the board with lead circuit; (2) transferring the pattern that needs to be electroplated through electroplating film to the board on which the lead circuit is engraved, electroplating, etching the leads, and obtaining the PCB board with electroplating completed. The process steps of the present invention are simplified, and the overhang of the nickel-gold layer in the electroplating area can be effectively avoided, and copper plating can be completed in one time, thereby improving production efficiency.

Description

Technical Field

[0001] The invention relates to the technical field of PCB production, and in particular to a PCB production process with lead electroplating inside the board. Background Art

[0002] In the production process of printed circuit boards (PCBs), local selective electroplating is required. However, the area that needs electroplating is often located in the middle of the unit and has patterns all around, so there is no space to add leads.

[0003] At this time, if the traditional method is adopted, the original bottom copper (i.e. the overall surface copper) is used as the conductive layer for electroplating, and the electroplating and electroplating of the electroplating area is first carried out, and then the electroplating and etching process of other patterns is carried out, and the copper plating needs to be divided into two parts, one before electroplating and one after electroplating, which is not only complicated but also time-consuming. At the same time, when the electroplating area is etched on the outer layer using this traditional process, film protection is required during the electroplating and tin stripping of the outer layer etching, which increases the hidden dangers of defects, and there will be a phenomenon of poor side etching of the nickel-gold surface, that is, nickel-gold overhang (nickel-gold loss), and nickel-gold overhang is a quality risk for printed circuit boards with increasingly stringent reliability requirements.

[0004] Therefore, it is of great significance to develop a simple and reliable production process for in-board electroplating. Summary of the invention

[0005] The purpose of the present invention is to provide a PCB production process for electroplating gold on leads in the board in view of the shortcomings of the prior art. The process steps are simplified, and the overhang of the nickel-gold layer in the electroplating gold area can be effectively avoided, and the copper plating can be completed in one time, thereby improving the production efficiency.

[0006] The purpose of the present invention is achieved through the following technical solutions.

[0007] A PCB production process with lead electroplating inside the board includes the following steps:

[0008] (1) Transferring the circuit pattern to the board after drilling, plated through hole (PTH) and board electrification through electroplating film, wherein the space of the unit circuit pattern closest to the edge of the board is sufficient to add a lead extending to the edge of the board, and adding a lead connected to the unit circuit pattern closest to the area where electroplating is required and with sufficient space in the area where electroplating is required; then, the pattern is electroplated, film stripped and etched to complete the engraving of the board with lead circuit;

[0009] (2) The pattern to be electroplated is transferred to the plate with the lead circuit engraved through the electroplating film, and the lead is etched after electroplating to obtain the PCB plate with completed electroplating.

[0010] Furthermore, in step (1), the unit circuit pattern closest to the edge of the sheet material and the unit circuit pattern closest to the area requiring conductive metal and having sufficient space are connected by a PCB circuit.

[0011] Furthermore, in step (1), the unit circuit pattern closest to the edge of the sheet material is directly connected to the unit circuit pattern closest to the area requiring conductive metal and having sufficient space by adding leads.

[0012] Furthermore, in step (1), the leads added between the unit circuit pattern closest to the edge of the sheet and the unit circuit pattern closest to the area requiring conductive metal and having sufficient space are etched away by the lead etching process of step (2).

[0013] Furthermore, the unit circuit pattern closest to the edge of the sheet and the unit circuit pattern closest to the area requiring electroplating and having sufficient space are connected to other unit circuit patterns with sufficient space between the two by adding leads, thereby achieving indirect connection.

[0014] Furthermore, the unit circuit pattern with sufficient space between the unit circuit pattern closest to the edge of the sheet and the unit circuit pattern closest to the area requiring the conductive metal and having sufficient space includes more than one independent unit circuit pattern, and the more than one independent unit circuit patterns are connected by adding leads; and the leads added between the more than one independent unit circuit patterns are etched by the lead etching process of step (2).

[0015] Furthermore, the leads added between the unit circuit pattern closest to the edge of the sheet and the unit circuit pattern closest to the conductive area and with sufficient space, which are connected to other unit circuit patterns with sufficient space between the two, are etched away by the lead etching process of step (2).

[0016] Furthermore, in any of the above processes, in step (1), one end of the connecting lead of the unit circuit pattern is further compensated according to the size alignment capability of the unit circuit pattern and the etching capability of the etching solution.

[0017] Because the leads are brought out by the unit circuit pattern, the size requirements of the unit circuit pattern cannot be affected when the leads are etched away. Therefore, when making the pattern for pattern electroplating, the non-electrometallurgical position of the lead end of the circuit pattern needs to be compensated and enlarged according to the size alignment ability of the unit circuit pattern, and a reserved position is used for the alignment deviation of the anti-etching layer when etching the leads. At the same time, because the edge of the unit circuit pattern will be attacked by the etching solution during etching, the edge of the pattern will become smaller, so the lead end of the circuit pattern also needs to be enlarged and compensated according to the etching ability of the etching solution.

[0018] Furthermore, without affecting the size of the circuit pattern, in the process of etching the lead in step (2), the portion of the added lead of the unit circuit pattern is etched away for compensation. The etched portion here includes the portion affected by the position deviation of the resist layer when etching the lead and the etching ability of the etching solution. During the etching process, the required circuit pattern is protected by using a dry film or other resist layer, and then the portion of the compensated end is etched away.

[0019] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0020] The process of the present invention can effectively avoid the overhang of the nickel-gold layer in the electroplated gold area, and the process steps are simplified, copper plating can be completed in one time, and production efficiency is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A schematic diagram of adding leads to a unit circuit pattern during the PCB board production process in Example 1;

[0022] Figure 2 A schematic diagram of the compensation for adding leads to a unit circuit pattern in the PCB board production process in Example 1;

[0023] Figure 3 This is a schematic diagram of the electroplating area after electroplating in the PCB board production process in Example 1;

[0024] Figure 4 This is a schematic diagram of the electroplating area after electroplating in the process of producing PCB boards using traditional technology;

[0025] Figure 5 A schematic diagram of adding leads to a unit circuit pattern in a PCB board production process in Example 3 and indirectly connecting two independent unit patterns with added leads;

[0026] The attached figure is marked with: nickel-gold layer 1, copper layer 2, substrate area 3, lead 5, lead compensation 6, and area requiring electroplating 7. DETAILED DESCRIPTION

[0027] The technical solution of the present invention is further described in detail below in conjunction with specific embodiments and drawings, but the protection scope and implementation methods of the present invention are not limited thereto.

[0028] Example 1

[0029] A PCB production process with lead electroplating inside the board specifically comprises the following steps:

[0030] (1) Transferring the circuit pattern to the board after drilling, electroplating through holes and board electrification through the electroplating film, wherein the space of the unit circuit pattern closest to the edge of the board is sufficient to add a lead extending to the edge of the board, and adding a lead connected to the unit circuit pattern closest to the area where the electroplating is required and with sufficient space in the area where the electroplating is required;

[0031] The unit circuit pattern closest to the edge of the sheet and the unit circuit pattern closest to the area where the conductive metal is required and has sufficient space are connected by PCB circuits, or directly connected by adding leads, such as Figure 1 As shown (in the figure, 5 represents the lead, 6 represents the compensation, and 7 represents the area requiring electroplating);

[0032] At the same time, one end of the connecting lead of the unit circuit pattern is compensated according to the size alignment ability of the unit circuit pattern and the etching ability of the etching solution, such as Figure 2 As shown;

[0033] (2) After the circuit pattern is transferred, it is electroplated, stripped and etched to complete the engraving of the board with lead circuit;

[0034] (3) The pattern to be electroplated is transferred to the plate with the lead circuit engraved through the electroplating film. The schematic diagram after electroplating is as follows: Figure 3 As shown, the nickel-gold layer 1 just covers the copper layer 2 on the substrate area 3, avoiding the undesirable phenomenon of the nickel-gold layer overhang after the traditional process of electroplating (such as Figure 4 As shown); remove the lead wires, and at the same time protect the circuit pattern with an anti-etching layer, and further compensate for the etching of the connecting lead ends of the unit circuit pattern to obtain a PCB board with completed electroplating.

[0035] Example 2

[0036] A PCB production process with lead electroplating inside the board specifically comprises the following steps:

[0037] (1) The circuit pattern is transferred to the sheet material after drilling, electroplating through holes and board electroplating through holes through electroplating film, wherein the space of the unit circuit pattern closest to the edge of the sheet material is sufficient to add a lead extending to the edge of the sheet material, and the lead connected to the unit circuit pattern closest to the area where the electroplating is required and has sufficient space is added in the area where the electroplating is required, and the unit circuit pattern closest to the edge of the sheet material is directly connected to the unit circuit pattern closest to the area where the electroplating is required and has sufficient space by adding a lead, see Figure 1 ;

[0038] At the same time, one end of the connecting lead of the unit circuit pattern is compensated according to the size alignment ability of the unit circuit pattern and the etching ability of the etching solution, see Figure 2 ;

[0039] (2) After the circuit pattern is transferred, it is electroplated, stripped and etched to complete the engraving of the board with lead circuit;

[0040] (3) The pattern to be electroplated is transferred to the plate with the lead circuit engraved through the electroplating film, and the schematic diagram after electroplating is shown in Figure 3 The nickel-gold layer 1 just covers the copper layer 2 on the substrate area 3, avoiding the undesirable phenomenon of nickel-gold layer overhang after traditional electroplating; the lead is etched away, and the circuit pattern is protected with an anti-etching layer. The connecting lead end of the unit circuit pattern is further compensated for by etching to obtain a PCB board with completed electroplating.

[0041] Example 3

[0042] A PCB production process with lead electroplating inside the board specifically comprises the following steps:

[0043] (1) The circuit pattern is transferred to the plate after drilling, electroplating through holes and board electrification through the electroplating film, wherein a lead extending to the edge of the plate is added at one end of the unit circuit pattern closest to the edge of the plate with sufficient space, and a lead connected to the unit circuit pattern closest to the area where the electroplating is required and with sufficient space is added in the area where the electroplating is required, and the unit circuit pattern closest to the edge of the plate and the unit circuit pattern closest to the area where the electroplating is required and with sufficient space are indirectly connected by adding a lead to connect two other independent unit circuit patterns with sufficient space between them, such as Figure 5 As shown;

[0044] At the same time, one end of the connecting lead of the unit circuit pattern is compensated according to the size alignment ability of the unit circuit pattern and the etching ability of the etching solution, see Figure 2 ;

[0045] (2) After the circuit pattern is transferred, it is electroplated, stripped and etched to complete the engraving of the board with lead circuit;

[0046] (3) The pattern to be electroplated is transferred to the plate with the lead circuit engraved through the electroplating film, and the schematic diagram after electroplating is shown in Figure 3 The nickel-gold layer 1 just covers the copper layer 2 on the substrate area 3, avoiding the undesirable phenomenon of nickel-gold layer overhang after traditional electroplating; the lead is etched away, and the circuit pattern is protected with an anti-etching layer. The connecting lead end of the unit circuit pattern is further compensated for by etching to obtain a PCB board with completed electroplating.

[0047] The above embodiments are preferred embodiments of the present invention, which are only intended to further describe the technical solutions of the present invention in detail, but do not limit the protection scope of the present invention. Any changes, substitutions or modifications that do not deviate from the spirit of the present invention shall be included in the protection scope of the present invention.

Claims

1. A PCB production process with lead electroplating inside the board, characterized in that: The steps include: (1) Transferring the circuit pattern to the sheet material after drilling, electroplating through holes and board electrification through the electroplating film, wherein the space of the unit circuit pattern closest to the edge of the sheet material is sufficient to add a lead extending to the edge of the sheet material, and adding a lead connected to the unit circuit pattern closest to the area requiring electroplating and with sufficient space in the area requiring electroplating; then, the pattern is electroplated, film stripped and etched to complete the engraving of the sheet material with lead circuit; (2) The pattern to be electroplated is transferred to the plate with the lead circuit engraved through the electroplating film, and the lead is etched after electroplating to obtain the PCB plate with completed electroplating; In step (1), the unit circuit pattern closest to the edge of the sheet and the unit circuit pattern closest to the area requiring electroplating and having sufficient space are connected to other unit circuit patterns with sufficient space between the two by adding leads, thereby achieving indirect connection; The other unit circuit patterns with sufficient space between the unit circuit pattern closest to the edge of the sheet and the unit circuit pattern closest to the area requiring electroplating and with sufficient space include more than one independent unit circuit patterns, and the more than one independent unit circuit patterns are connected by adding leads; and the added leads between the more than one independent unit circuit patterns are etched through the lead etching process of step (2).

2. A PCB production process with lead electroplating in the board according to claim 1, characterized in that: In step (1), the unit circuit pattern closest to the edge of the sheet material is connected to the unit circuit pattern closest to the area requiring conductive metal and having sufficient space by a PCB circuit.

3. The PCB production process for lead electroplating according to claim 1 is characterized in that: In step (1), the unit circuit pattern closest to the edge of the sheet material is directly connected to the unit circuit pattern closest to the area requiring conductive metal and having sufficient space by adding leads.

4. A PCB production process with lead electroplating in the board according to claim 3, characterized in that: The leads added between the unit circuit pattern closest to the edge of the sheet and the unit circuit pattern closest to the area requiring electroplating and with sufficient space are etched away by the lead etching process of step (2).

5. The PCB production process with lead electroplating in the board according to claim 1 is characterized in that: The leads added between the unit circuit pattern closest to the edge of the sheet and the unit circuit pattern closest to the area requiring electroplating and with sufficient space, and connected to other unit circuit patterns with sufficient space between the two, are etched away by the lead etching process of step (2).

6. A PCB production process with lead electroplating in the board according to any one of claims 1 to 5, characterized in that: In step (1), one end of the connecting lead of the unit circuit pattern is compensated according to the size alignment capability of the unit circuit pattern and the etching capability of the etching solution.

7. A PCB production process with lead electroplating in the board according to claim 6, characterized in that: Without affecting the size of the circuit pattern, during the process of etching the lead in step (2), the portion of the unit circuit pattern at one end of the added lead is etched away for compensation.

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