Manufacturing method of insulating printed circuit board based on high voltage resistance

Abstract

The invention discloses a manufacturing method of an insulating printed circuit board based on high voltage resistance. The manufacturing method comprises the following steps: S1, mixing ceramic powder and polyimide, and heating and curing to form a base material; s2, pollutants on the surface of the base material are removed through a plasma cleaning technology, and the binding force of the base material and a subsequent layer is improved; s3, transferring a circuit pattern to the surface of the base material on the base material through a laser direct writing technology; s4, performing deposition on the circuit pattern through a vacuum deposition technology to form a copper film layer; s5, performing mask manufacturing by using photoresist, and removing the copper film layer which is not covered by the mask through wet or dry etching to form a circuit; s6, a laser drilling technology is used for drilling micropores, and the inner walls of the micropores are metalized through a chemical copper plating technology; and S7, after circuit manufacturing is completed, ultraviolet light curing epoxy resin is used as an insulating coating. The circuit board material and the implementation method are innovated, so that the problems in the prior art are solved, and the voltage resistance, the insulating property and the reliability of the circuit board are improved.

Description

Technical Field

[0001] The invention relates to the field of circuit board manufacturing technology, in particular to a method for manufacturing a high voltage resistant insulated printed circuit board. Background Art

[0002] With the development of electronic technology, printed circuit boards are increasingly used in electronic equipment. In some special application scenarios, according to high-voltage power systems, aerospace, military equipment, etc., printed circuit boards need to withstand higher voltages without breakdown. However, due to the limitations of their materials and manufacturing processes, traditional printed circuit boards often cannot meet the requirements of these special occasions. Therefore, developing an insulated printed circuit board with high voltage resistance has become an important research direction.

[0003] The existing high-voltage resistant printed circuit boards mainly have the following problems: 1. The selection and processing technology of the substrate are insufficient, resulting in poor dielectric properties of the substrate. 2. The precision of the conductive pattern is not high, which makes it difficult to meet the needs of high-frequency signal transmission. 3. The hole processing and metallization processes are not fine enough, making it difficult to achieve high-density interconnection. 4. The reliability and durability of the insulating coating need to be improved. In order to solve the above problems, the present invention proposes an insulating printed circuit board based on high-voltage resistance and a manufacturing method thereof. Summary of the invention

[0004] In view of this, the present invention aims at the deficiencies in the prior art, and its main purpose is to provide a manufacturing method for a high-voltage resistant insulated printed circuit board, solve the problems existing in the prior art, and improve the voltage resistance, insulation performance and reliability of the printed circuit board.

[0005] To achieve the above purpose, the present invention adopts the following technical solution:

[0006] A method for manufacturing a high voltage resistant insulated printed circuit board comprises the following steps:

[0007] S1, forming a substrate by mixing ceramic powder and polyimide and heating and curing;

[0008] S2, using plasma cleaning technology to remove pollutants on the surface of the substrate and improve the bonding strength between the substrate and subsequent layers;

[0009] S3, transferring the circuit pattern to the surface of the substrate by laser direct writing technology on the substrate;

[0010] S4, depositing a copper film layer on the circuit pattern by vacuum deposition technology;

[0011] S5, using photoresist to make a mask, and then removing the copper film layer not covered by the mask by wet or dry etching to form a circuit;

[0012] S6. Use laser drilling technology to drill microholes where electrical connections are required, and metalize the inner wall of the hole through chemical copper plating process;

[0013] S7. After the circuit is fabricated, use UV-curable epoxy resin as an insulating coating.

[0014] As a preferred embodiment, the substrate is formed by the following steps: mixing ceramic powder and polyimide, with the mixing ratio being 30% of the total weight of the ceramic powder; spreading the mixture in a mold and heating and curing it at a temperature of 150°C for 3 hours; cooling to room temperature after curing and taking out the formed substrate.

[0015] As a preferred solution: the circuit pattern is formed by the following steps: using a laser direct imaging device to project the circuit design pattern onto the surface of the substrate, with the laser power set to 10W; after laser irradiation, a photosensitive layer is formed on the surface of the substrate.

[0016] As a preferred solution: the copper film layer is formed by the following steps: placing copper foil on the surface of the substrate, the thickness of the copper foil is 18μm; placing the substrate in a vacuum chamber for vacuum deposition, the deposition pressure is 10^-3Pa, and the deposition time is 30 minutes; after the deposition is completed, removing excess copper foil, leaving a circuit pattern.

[0017] As a preferred solution: the microholes are formed by the following steps: using ultra-pulse laser drilling equipment to drill microholes at the desired position on the substrate, the laser frequency is 20kHz, and the power is 15W; after drilling, the hole wall is cleaned to remove residual substances; the metallization of the inner wall of the microhole is completed by the following steps: a layer of copper is deposited on the inner wall of the microhole by a chemical copper plating process, and the deposition rate is 0.5μm / min; ensuring that the inner wall of the hole is completely covered with metal to achieve electrical connection.

[0018] As a preferred solution, the insulating coating is formed by the following steps: spraying a layer of UV-curable epoxy resin on the entire surface of the circuit board, with a coating thickness of 20 μm to 50 μm; using a UV curing device to cure the coating, with a UV intensity of 1000 mJ / cm 2 .

[0019] As a preferred solution: repeat steps S3-S7 to form a multi-layer circuit board having a substrate layer, a copper film layer and an insulating coating layer, the multiple layers are bonded by hot rolling, and the layers are connected by micropores to achieve multi-layer interconnection to form a multi-layer circuit board; the multi-layer circuit board includes a signal layer, a ground layer and a power layer, the signal layer is adjacent to the ground layer, and the power layer and the ground layer are paired.

[0020] As a preferred solution: chemical nickel-gold treatment is performed on the surface of the circuit board, and the thickness of the nickel-gold treatment layer is 0.025 μm to 0.1 μm.

[0021] As a preferred solution: the circuit board is subjected to a high voltage test by the following steps: placing the circuit board in a high voltage test device; applying a predetermined voltage and maintaining it for 60 seconds; ensuring that it can withstand a voltage of at least 1000 volts without breakdown.

[0022] As a preferred solution: the circuit board is quality inspected through the following steps: visually inspecting the circuit board using automatic optical inspection equipment; inspecting the inside of the circuit board using X-ray inspection equipment; recording the inspection results and analyzing whether there are defects.

[0023] Compared with the prior art, the present invention has obvious advantages and beneficial effects. Specifically, it can be seen from the above technical scheme that by using a substrate mixed with ceramic powder and polyimide, the circuit board has better high-voltage and heat resistance, providing a solid physical foundation for the circuit board; using laser direct writing technology, a finer and more accurate circuit pattern transfer is achieved than traditional screen printing; using plasma cleaning technology, compared with traditional chemical cleaning methods, it can more effectively remove pollutants and improve the bonding strength between the substrate and the copper film layer; using vacuum deposition technology to replace traditional electroplating or chemical copper plating, providing a more uniform copper film layer and reducing defects; using plasma cleaning and chemical copper plating processes to enhance the bonding strength between the substrate and the copper film layer and improve the overall stability of the circuit board; through multi-layer structure design and hot roller pressing bonding technology, complex circuit layout and high-density integration are achieved; using automatic optical detection and X-ray detection, a more efficient and reliable quality control process is provided than traditional manual detection. Due to the use of high-voltage resistant materials and precise manufacturing processes, the circuit board can be used in a variety of environments.

[0024] In order to more clearly illustrate the structural features and effects of the present invention, it is described in detail below in conjunction with the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 The present invention is a schematic flow chart of a method for manufacturing a high voltage resistant insulated printed circuit board. DETAILED DESCRIPTION

[0026] The present invention is based on Figure 1 As shown, a method for manufacturing an insulated printed circuit board based on high voltage resistance comprises the following steps:

[0027] S1. Form a substrate by mixing ceramic powder and polyimide and heating and curing; the substrate is formed by the following steps: mixing ceramic powder and polyimide, the mixing ratio is 30% of the total weight of ceramic powder; spreading the mixture in a mold and heating and curing, the curing temperature is 150°C, the time is 3 hours; after curing, cool to room temperature and take out the formed substrate. The substrate is formed by mixing ceramic powder and polyimide. This material combination generally has excellent high pressure resistance and heat resistance. In addition, the preparation process of the substrate includes precise temperature and time control to ensure uniform curing of the material, which is crucial to improving product reliability.

[0028] S2. Use plasma cleaning technology to remove pollutants on the surface of the substrate and improve the bonding strength between the substrate and subsequent layers; specifically, use plasma cleaning equipment to clean the surface of the substrate, with the power set to 500W and the cleaning time set to 10 minutes; remove grease and other pollutants on the surface of the substrate; improve the hydrophilicity and adhesion of the substrate surface, and improve the bonding strength between the substrate and subsequent layers. Using plasma cleaning technology to remove pollutants on the surface of the substrate and improve the bonding strength between the substrate and subsequent layers is crucial to the long-term stability and performance of the circuit board.

[0029] S3, transferring the circuit pattern to the surface of the substrate by laser direct writing technology; the circuit pattern is formed by the following steps: using a laser direct imaging device to project the circuit design pattern onto the surface of the substrate, the laser power is set to 10W; after laser irradiation, a photosensitive layer is formed on the surface of the substrate. Laser direct writing technology has high precision and can produce fine circuit patterns.

[0030] S4. A copper film layer is formed on the circuit pattern by vacuum deposition technology; the copper film layer is formed by the following steps: placing a copper foil on the surface of the substrate, the thickness of the copper foil is 18 μm; placing the substrate in a vacuum chamber for vacuum deposition, the deposition pressure is 10^-3Pa, and the deposition time is 30 minutes; after the deposition is completed, the excess copper foil is removed, leaving the circuit pattern. Vacuum deposition technology is used to form a copper film layer, which can provide uniform deposition and help improve the conductivity and reliability of the circuit.

[0031] S5. Use photoresist to make a mask, and then remove the copper film layer not covered by the mask by wet or dry etching to form a circuit.

[0032] S6. Use laser drilling technology to drill microholes where electrical connection is required, and metalize the inner wall of the hole through chemical copper plating process; the microhole is formed by the following steps: use ultra-pulsed laser drilling equipment to drill microholes at the required position on the substrate, the laser frequency is 20kHz, and the power is 15W; after drilling, the hole wall is cleaned to remove residual substances; the metallization of the inner wall of the microhole is completed by the following steps: deposit a layer of copper on the inner wall of the microhole through chemical copper plating process, and the deposition rate is 0.5μm / min; ensure that the inner wall of the hole is completely covered with metal to achieve electrical connection. Use laser drilling technology to make microholes, and metalize the inner wall of the hole through chemical copper plating process. This method can accurately control the position and size of the hole and achieve precise electrical connection.

[0033] S7. After the circuit is fabricated, use UV-curable epoxy resin as an insulating coating to protect the circuit from the external environment. The insulating coating is formed by the following steps: spraying a layer of UV-curable epoxy resin on the entire surface of the circuit board, with a coating thickness of 20 μm to 50 μm; using UV-curing equipment to cure the coating, with a UV light intensity of 1000 mJ / cm 2 .

[0034] Repeat steps S3-S7 to form a multi-layer circuit board having a substrate layer, a copper film layer and an insulating coating. The multi-layers are bonded by hot rolling, and the layers are connected by micro-holes to achieve multi-layer interconnection to form a multi-layer circuit board; the multi-layer circuit board includes a signal layer, a ground layer and a power layer, the signal layer is adjacent to the ground layer, and the power layer and the ground layer are paired. By rationally planning the stacking structure, ensure that each signal layer has an adjacent reference layer to provide a larger coupling capacitance and a good shielding effect. By bonding the multiple layers by hot rolling and achieving multi-layer interconnection through micro-hole connection, this structure can provide complex circuit design and higher integration.

[0035] In addition, the circuit board surface is treated with chemical nickel-gold, and the thickness of the nickel-gold treatment layer is 0.025 μm to 0.1 μm. The corrosion resistance and conductivity of the circuit board are improved by chemical nickel-gold treatment.

[0036] The circuit board is subjected to a high voltage test through the following steps: the circuit board has a dielectric constant of 4.0 to 4.5; the circuit board is placed in a high voltage test device; a predetermined voltage is applied and maintained for 60 seconds; it is ensured that it can withstand a voltage of at least 1000 volts without breakdown, and that the product can operate normally within the specified voltage range.

[0037] The circuit board is inspected for quality through the following steps: visual inspection of the circuit board using automatic optical inspection equipment; internal inspection of the circuit board using X-ray inspection equipment; recording the inspection results and analyzing whether there are defects to ensure product quality. Using automatic optical inspection equipment and X-ray inspection equipment for quality inspection, these advanced inspection methods can ensure the quality and reliability of the circuit board.

[0038] The circuit board uses a substrate formed by mixing ceramic powder and polyimide and heating and curing, which can ensure that no breakdown occurs under high voltage; at the same time, the material has good mechanical strength and heat resistance.

[0039] The design focus of the present invention is that by using a substrate mixed with ceramic powder and polyimide, the circuit board has better high-voltage and heat-resistant performance, providing a solid physical foundation for the circuit board; using laser direct writing technology to achieve finer and more accurate circuit pattern transfer than traditional screen printing; using plasma cleaning technology, compared with traditional chemical cleaning methods, it can more effectively remove pollutants and improve the bonding strength between the substrate and the copper film layer; using vacuum deposition technology to replace traditional electroplating or chemical copper plating, providing a more uniform copper film layer and reducing defects; using plasma cleaning and chemical copper plating processes to enhance the bonding strength between the substrate and the copper film layer and improve the overall stability of the circuit board; through multi-layer structure design and hot roller pressing and laminating technology, complex circuit layout and high-density integration are achieved; using automatic optical detection and X-ray detection, a more efficient and reliable quality control process is provided than traditional manual detection. Due to the use of high-voltage resistant materials and precise manufacturing processes, the circuit board can be used in a variety of environments.

[0040] The above description is only a preferred embodiment of the present invention and does not limit the technical scope of the present invention. Therefore, any slight modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A method for manufacturing an insulated printed circuit board based on high voltage resistance, characterized in that: The following steps are involved: S1, forming a substrate by mixing ceramic powder and polyimide and heating and curing; S2, using plasma cleaning technology to remove pollutants on the surface of the substrate and improve the bonding strength between the substrate and subsequent layers; S3, transferring the circuit pattern to the surface of the substrate by laser direct writing technology on the substrate; S4, depositing a copper film layer on the circuit pattern by vacuum deposition technology; S5, using photoresist to make a mask, and then removing the copper film layer not covered by the mask by wet or dry etching to form a circuit; S6. Use laser drilling technology to drill microholes where electrical connections are required, and metalize the inner wall of the hole through chemical copper plating process; S7. After the circuit is fabricated, use UV-curable epoxy resin as an insulating coating.

2. The method for manufacturing a high voltage resistant insulated printed circuit board according to claim 1, characterized in that: The substrate is formed by the following steps: mixing ceramic powder and polyimide, with the mixing ratio being 30% of the total weight of the ceramic powder; spreading the mixture in a mold and heating and curing it, with the curing temperature being 150° C. for 3 hours; cooling to room temperature after curing and taking out the formed substrate.

3. The method for manufacturing a high voltage resistant insulated printed circuit board according to claim 1, characterized in that: The circuit pattern is formed by the following steps: using a laser direct imaging device to project the circuit design pattern onto the surface of the substrate, with the laser power set to 10W; after laser irradiation, a photosensitive layer is formed on the surface of the substrate.

4. The method for manufacturing a high voltage resistant insulated printed circuit board according to claim 1, characterized in that: The copper film layer is formed by the following steps: placing a copper foil on the surface of the substrate, the thickness of the copper foil is 18 μm; placing the substrate in a vacuum chamber for vacuum deposition, the deposition pressure is 10^-3Pa, and the deposition time is 30 minutes; after the deposition is completed, removing the excess copper foil, leaving the circuit pattern.

5. The method for manufacturing a high voltage resistant insulated printed circuit board according to claim 1, characterized in that: The microholes are formed by the following steps: using ultra-pulse laser drilling equipment to drill microholes at the desired positions on the substrate, with a laser frequency of 20kHz and a power of 15W; cleaning the hole walls after drilling to remove residual substances; the metallization of the inner walls of the microholes is completed by the following steps: depositing a layer of copper on the inner walls of the microholes by a chemical copper plating process at a deposition rate of 0.5μm / min; ensuring that the inner walls of the holes are completely covered with metal to achieve electrical connection.

6. The method for manufacturing a high voltage resistant insulated printed circuit board according to claim 1, characterized in that: The insulating coating is formed by the following steps: spraying a layer of ultraviolet light-cured epoxy resin on the entire surface of the circuit board, with a coating thickness of 20 μm to 50 μm; using ultraviolet light curing equipment to cure the coating, with an ultraviolet light intensity of 1000 mJ / cm 2 .

7. The method for manufacturing a high voltage resistant insulated printed circuit board according to claim 1, characterized in that: Repeat steps S3-S7 to form a multi-layer circuit board having a substrate layer, a copper film layer and an insulating coating. The multiple layers are bonded together by hot rolling, and the layers are connected by micropores to achieve multi-layer interconnection to form a multi-layer circuit board; the multi-layer circuit board includes a signal layer, a ground layer and a power layer, the signal layer is adjacent to the ground layer, and the power layer and the ground layer are paired.

8. The method for manufacturing a high voltage resistant insulated printed circuit board according to claim 1, characterized in that: The circuit board surface is treated with chemical nickel-gold, and the thickness of the nickel-gold treatment layer is 0.025 μm to 0.1 μm.

9. The method for manufacturing a high voltage resistant insulated printed circuit board according to claim 1, characterized in that: The circuit board is subjected to a high voltage test by the following steps: placing the circuit board in a high voltage test device; applying a predetermined voltage and maintaining it for 60 seconds; ensuring that it can withstand a voltage of at least 1000 volts without breakdown.

10. The method for manufacturing a high voltage resistant insulated printed circuit board according to claim 1, characterized in that: The circuit board is quality inspected by the following steps: visually inspecting the circuit board using an automatic optical inspection device; inspecting the inside of the circuit board using an X-ray inspection device; and recording the inspection results and analyzing whether there are any defects.

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