A method for manufacturing a high-voltage resistant ultra-thick copper PCB board

Abstract

The present invention discloses a method for manufacturing a high-voltage resistant ultra-thick copper PCB board, comprising the following steps: S1 cutting, S2 inner layer circuit, S3 inner layer lamination, S4 drilling, S5 conductive glue, S6 VCP electroplating, S7 outer layer circuit, S8 resin printing, S9 leveling, S10 outer layer lamination, S11 laser windowing, S12 flash plating, S13 pad pattern, S14 pattern electroplating, S15 alkaline etching, S16 text, S17 tin spraying, S18 molding, S19 electrical measurement, S20 inspection, S21 packaging. The present invention provides a method for manufacturing a high-voltage resistant ultra-thick copper PCB board, which adopts resin printing and PP lamination to replace traditional silk screen solder resist ink, and the high voltage resistance can be increased from the conventional 3000V or less to 5000V or more; and the PCB board manufactured by the method of the present invention has good consistency between the pad pattern and the insulating layer around the pad, and is more conducive to the application of high-end components such as surface mounted small-pitch ICs while ensuring insulation.

Description

Technical Field

[0001] The invention relates to the technical field of PCB boards, and in particular to a method for manufacturing a high-voltage resistant ultra-thick copper PCB board. Background Art

[0002] With the development trend of miniaturization and integration of electronic products, PCB boards, as one of the core components of electronic products, are also developing towards high density, high multi-layer and thick copper characteristics. Among them, ultra-thick copper PCB boards are widely used in some high-power electrical appliances, power supplies and other equipment fields, and such PCB boards generally need to withstand high voltage. On the surface of conventional PCB boards, solder mask ink is screen-printed between the lines to achieve the purpose of electrical insulation. However, for ultra-thick copper PCB boards above 300um, due to the large height difference between the copper thickness on the board surface and the substrate, it is difficult for the ink to flow into the gaps of all thick copper graphics after screen printing, or the ink thickness is too thin in the dense circuit area after screen printing, so that the method of screen printing solder mask ink can generally only withstand high voltages below 3000V.

[0003] Based on the above situation, the present invention proposes a method for manufacturing a high-voltage resistant ultra-thick copper PCB board, which can effectively solve the above problems. Summary of the invention

[0004] The purpose of the present invention is to provide a method for manufacturing a high-voltage resistant ultra-thick copper PCB board. The present invention provides a method for manufacturing a high-voltage resistant ultra-thick copper PCB board, which adopts resin printing and PP lamination to replace the traditional silk screen solder resist ink, and the high voltage resistance can be increased from the conventional 3000V or less to 5000V or more; and the PCB board manufactured by the method of the present invention has a good consistency between the pad pattern and the insulating layer around the pad, which is more conducive to the application of high-end components such as surface mounted small-pitch ICs while ensuring insulation.

[0005] The present invention is achieved through the following technical solutions:

[0006] A method for manufacturing a high-voltage resistant ultra-thick copper PCB board comprises the following steps: S1, cutting, S2, inner layer circuit, S3, inner layer pressing, S4, drilling, S5, conductive adhesive, S6, VCP electroplating, S7, outer layer circuit, S8, resin printing, S9, leveling, S10, outer layer pressing, S11, laser windowing, S12, flash plating, S13 pad pattern, S14, pattern electroplating, S15, alkaline etching, S16, text, S17, tin spraying, S18, molding, S19, electrical measurement, S20, inspection, S21, packaging.

[0007] The present invention provides a method for manufacturing a high-voltage resistant ultra-thick copper PCB board, which adopts resin printing and PP lamination to replace traditional silk-screen solder resist ink, and the high voltage resistance can be increased from the conventional 3000V or less to 5000V or more; and the PCB board manufactured by the method of the present invention has a good consistency between the pad pattern and the insulating layer height around the pad, which is more conducive to the application of high-end components such as surface mounted small-pitch ICs while ensuring insulation.

[0008] According to the above technical solution, as a further preferred technical solution of the above technical solution, step S8 is specifically implemented as the following steps:

[0009] S8.1. Remove foreign matter such as oxidation from the surface of the PCB board by ultra-roughening chemical treatment or sandblasting;

[0010] S8.2, using a tunnel oven to bake the PCB board once, the baking temperature is 120° C., and the baking time is 120 min;

[0011] S8.3. Select a copper-free copper-clad laminate with a thickness of 0.1 to 0.3 mm. Use a precision milling machine to hollow out the copper-clad laminate area at the corresponding position on the PCB board that needs to be filled with resin, and then use glue to fix it to the screen of the screen printer of the printing press. Then further remove the screen in the effective area of ​​the copper-clad laminate, and finally use solvent-resistant tape to seal the copper-clad laminate and the screen.

[0012] According to the above technical solution, as a further preferred technical solution of the above technical solution, step S9 is specifically implemented as the following steps:

[0013] S9.1. Send the PCB board to the leveling machine to level the surface of the printed resin on the PCB board;

[0014] S9.2, putting the leveled PCB board into a tunnel furnace for secondary baking, wherein the secondary baking is segmented baking, and the secondary baking is sequentially carried out at 60° C. for 10 min, 90° C. for 20 min, and 120° C. for 90 min.

[0015] According to the above technical solution, as a further preferred technical solution of the above technical solution, step S10 is specifically implemented as the following steps:

[0016] S10.1. Pre-stack 106PP and release film on the upper and lower surfaces of the PCB board respectively;

[0017] S10.2. Set corresponding lamination parameters according to the Tg value of the PCB board resin, and laminate the PCB board, 106PP and release film.

[0018] According to the above technical solution, as a further preferred technical solution of the above technical solution, the step S11 is specifically implemented as the following steps:

[0019] S11.1. Remove the PP and resin from the PCB surface where the solder pad pattern is required;

[0020] S11.1. Use CO2 laser equipment and perform ablation through multiple pulses.

[0021] According to the above technical solution, as a further preferred technical solution of the above technical solution, the step S12 is specifically implemented as follows: electroplating a 1-3 um thin copper layer on the surface of the PCB board and the laser window opening area of ​​step S11.

[0022] According to the above technical solution, as a further preferred technical solution of the above technical solution, step S13 is specifically implemented as the following steps:

[0023] S13.1. Apply a layer of photosensitive dry film on the surface of the PCB;

[0024] S13.2, performing registration exposure by ultraviolet irradiation;

[0025] S13.3. Use a sodium carbonate or potassium carbonate developer with a mass concentration of 0.8% to 1.2% to develop the solder pad pattern on the surface of the PCB board.

[0026] According to the above technical scheme, as a further preferred technical scheme of the above technical scheme, the step S14 is specifically implemented as follows: the required electroplating time is calculated according to the electroplating area, and the pattern electroplating is performed after the electroplating parameters are set, and the copper thickness of the pad area on the surface of the PCB board after electroplating is 0 to 25 um higher than the height of the insulating layer of the PCB board.

[0027] According to the above technical solution, as a further preferred technical solution of the above technical solution, step S15 is specifically implemented as the following steps:

[0028] S15.1. Etch out the outer circuit pattern using etching solution;

[0029] S15.2. Use a four-axis heavy-duty ceramic brush grinder or a sanding belt grinder to grind the PCB.

[0030] According to the above technical solution, as a further preferred technical solution of the above technical solution, in step S8.3, the speed of the printing press is set to 2.6m / min, and the scraper pressure is set to 5.5Kg / cm 2 .

[0031] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0032] The present invention provides a method for manufacturing a high-voltage resistant ultra-thick copper PCB board, which adopts resin printing and PP lamination to replace traditional silk-screen solder resist ink, and the high voltage resistance can be increased from the conventional 3000V or less to 5000V or more; and the PCB board manufactured by the method of the present invention has a good consistency between the pad pattern and the insulating layer height around the pad, which is more conducive to the application of high-end components such as surface mounted small-pitch ICs while ensuring insulation. DETAILED DESCRIPTION

[0033] In order to enable those skilled in the art to better understand the technical solution of the present invention, the preferred implementation scheme of the present invention is described below in conjunction with specific examples.

[0034] A method for manufacturing a high-voltage resistant ultra-thick copper PCB board comprises the following steps: S1, cutting, S2, inner layer circuit, S3, inner layer pressing, S4, drilling, S5, conductive adhesive, S6, VCP electroplating, S7, outer layer circuit, S8, resin printing, S9, leveling, S10, outer layer pressing, S11, laser windowing, S12, flash plating, S13 pad pattern, S14, pattern electroplating, S15, alkaline etching, S16, text, S17, tin spraying, S18, molding, S19, electrical measurement, S20, inspection, S21, packaging.

[0035] The present invention provides a method for manufacturing a high-voltage resistant ultra-thick copper PCB board, which adopts resin printing and PP lamination to replace traditional silk-screen solder resist ink, and the high voltage resistance can be increased from the conventional 3000V or less to 5000V or more; and the PCB board manufactured by the method of the present invention has a good consistency between the pad pattern and the insulating layer height around the pad, which is more conducive to the application of high-end components such as surface mounted small-pitch ICs while ensuring insulation.

[0036] Further, in another embodiment, step S8 is specifically implemented as the following steps:

[0037] S8.1. Remove foreign matter such as oxidation on the surface of the PCB board through ultra-roughening chemical treatment or sandblasting; thereby ensuring the bonding strength between the printed resin and the PCB board;

[0038] S8.2, use a tunnel oven to bake the PCB board once, the baking temperature is 120°C, and the baking time is 120 minutes. The purpose of the present invention is to remove the moisture in the PCB board, thereby reducing the stress in the board.

[0039] S8.3. Select a copper-free copper-clad laminate with a thickness of 0.1 to 0.3 mm. Use a precision milling machine to hollow out the copper-clad laminate area at the corresponding position on the PCB board that needs to be filled with resin, and then use glue to fix it to the screen of the screen printer of the printing press. Then further remove the screen in the effective area of ​​the copper-clad laminate, and finally use solvent-resistant tape to seal the copper-clad laminate and the screen.

[0040] Further, in another embodiment, the step S9 is specifically implemented as the following steps:

[0041] S9.1. Send the PCB board to the leveling machine to level the surface of the printed resin on the PCB board;

[0042] S9.2, put the leveled PCB board into a tunnel furnace for secondary baking, the secondary baking is segmented baking, the secondary baking is sequentially baking at 60°C for 10 minutes, baking at 90°C for 20 minutes, and baking at 120°C for 90 minutes. The purpose of the secondary baking of the present invention is to firmly fix the printed resin and the PCB board together to form an integrated structure.

[0043] Further, in another embodiment, the step S10 is specifically implemented as the following steps:

[0044] S10.1. Pre-stack 106PP and release film on the upper and lower surfaces of the PCB board respectively;

[0045] S10.2, according to the Tg value of the PCB board resin, set the corresponding pressing parameters, and laminate the PCB board, 106PP and release film. It should be noted that in step S8.3, since the printed resin is prone to bubbles, it is necessary to reduce the pressing pressure by 10% and the pre-Tg heating rate by 20% on the conventional PCB board pressing parameters during lamination.

[0046] Furthermore, in another embodiment, the step S11 is specifically implemented as the following steps:

[0047] S11.1. Remove the PP and resin from the PCB surface where the solder pad pattern is required;

[0048] S11.1. Use CO2 laser equipment and perform ablation through multiple pulses.

[0049] Furthermore, in another embodiment, the step S12 is specifically implemented as follows: electroplating a thin copper layer of 1 to 3 um on the surface of the PCB board and the laser window opening area of ​​step S11.

[0050] Further, in another embodiment, the step S13 is specifically implemented as the following steps:

[0051] S13.1. Apply a layer of photosensitive dry film on the surface of the PCB;

[0052] S13.2, performing registration exposure by ultraviolet irradiation;

[0053] S13.3. Use a sodium carbonate or potassium carbonate developer with a mass concentration of 0.8% to 1.2% to develop the solder pad pattern on the surface of the PCB board.

[0054] Furthermore, in another embodiment, the step S14 is specifically implemented as follows: the required plating time is calculated according to the plating area, and the pattern plating is performed after the plating parameters are set, and the copper thickness of the pad area on the surface of the PCB board after plating is 0 to 25 um higher than the height of the insulating layer of the PCB board.

[0055] Further, in another embodiment, the step S15 is specifically implemented as the following steps:

[0056] S15.1. Etch out the outer circuit pattern using etching solution;

[0057] S15.2. Use a four-axis heavy-duty ceramic brush grinder or a sanding belt grinder to grind the PCB.

[0058] Furthermore, in another embodiment, due to the high viscosity of resin printing, the printing speed is reduced by 20%-30% compared with conventional solder resist ink, and the scraper pressure needs to be increased by 15%-20%. Therefore, in step S8.3, the speed of the printer is set to 2.6m / min and the scraper pressure is set to 5.5Kg / cm 2 .

[0059] It should be noted that the manufacturing methods of the processes of cutting, inner layer circuit, inner layer lamination, drilling, conductive adhesive, VCP electroplating, and outer layer circuit of the present invention are consistent with those of conventional multi-layer PCB boards, and the manufacturing methods of the subsequent text, tin spraying, molding, electrical testing, inspection, and packaging are also consistent with those of conventional PCB boards, so the present invention does not elaborate on them in detail.

[0060] Unless otherwise clearly specified and limited, in the present invention, the terms "disposed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0061] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification or equivalent change made to the above embodiment based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A method for manufacturing a high-voltage resistant ultra-thick copper PCB, characterized in that: The method comprises the following steps: S1, cutting, S2, inner layer circuit, S3, inner layer lamination, S4, drilling, S5, conductive adhesive, S6, VCP electroplating, S7, outer layer circuit, S8, resin printing, S9, leveling, S10, outer layer lamination, S11, laser windowing, S12, flash plating, S13 pad pattern, S14, pattern electroplating, S15, alkaline etching, S16, text, S17, tin spraying, S18, molding, S19, electrical measurement, S20, inspection, S21, packaging; The step S8 is specifically implemented as follows: S8.

1. Remove oxidized foreign matter from the surface of the PCB by ultra-roughening chemical treatment or sandblasting; S8.2, using a tunnel oven to bake the PCB board once, the baking temperature is 120° C., and the baking time is 120 min; S8.

3. Select a copper-free copper-clad laminate with a thickness of 0.1 to 0.3 mm, use a precision milling machine to hollow out the copper-clad laminate area at the corresponding position on the PCB board that needs to be filled with resin, and then use glue to fix it to the screen of the screen printer of the printing press, and then further remove the screen in the effective area of ​​the copper-clad laminate, and finally use solvent-resistant tape to seal the copper-clad laminate and the screen; The step S9 is specifically implemented as follows: S9.

1. Send the PCB board to the leveling machine to level the surface of the printed resin on the PCB board; S9.2, put the leveled PCB board into a tunnel furnace for secondary baking, wherein the secondary baking is staged baking, and baking is performed at 60°C for 10 min, 90°C for 20 min, and 120°C for 90 min in sequence; The step S10 is specifically implemented as follows: S10.

1. Pre-stack 106PP and release film on the upper and lower surfaces of the PCB board respectively; S10.

2. Set corresponding lamination parameters according to the Tg value of the PCB board resin, and laminate the PCB board, 106PP and release film; The step S11 is specifically implemented as follows: S11.

1. Remove the PP and resin from the PCB surface where the solder pad pattern is required; S11.

1. Use CO2 laser equipment to perform ablation by multiple pulses; The step S14 is specifically implemented as follows: the required electroplating time is calculated according to the electroplating area, and pattern electroplating is performed after the electroplating parameters are set, and the copper thickness of the pad area on the surface of the PCB board after electroplating is 0 to 25 um higher than the height of the insulating layer of the PCB board.

2. The method for manufacturing a high-pressure resistant ultra-thick copper PCB according to claim 1, characterized in that: The step S12 is specifically implemented as follows: electroplating a thin copper layer of 1 to 3 um on the surface of the PCB board and the laser window opening area of ​​step S11.

3. The method for manufacturing a high-pressure resistant ultra-thick copper PCB according to claim 1, characterized in that: The step S13 is specifically implemented as follows: S13.

1. Apply a layer of photosensitive dry film on the surface of the PCB; S13.2, performing registration exposure by ultraviolet irradiation; S13.

3. Use a sodium carbonate or potassium carbonate developer with a mass concentration of 0.8% to 1.2% to develop the solder pad pattern on the surface of the PCB board.

4. The method for manufacturing a high-pressure resistant ultra-thick copper PCB according to claim 1, characterized in that: The step S15 is specifically implemented as follows: S15.

1. Etch out the outer circuit pattern using etching solution; S15.

2. Use a four-axis heavy-duty ceramic brush grinder or a sanding belt grinder to grind the PCB.

5. The method for manufacturing a high-pressure resistant ultra-thick copper PCB according to claim 1, characterized in that: In step S8.3, the speed of the printing press is set to 2.6 m / min and the scraper pressure is set to 5.5 kg / cm 2 .