Preparation process of circuit board

Abstract

The invention relates to the technical field of circuit processing, in particular to a preparation process of a circuit board, which comprises the following steps of: S1, carrying out surface treatment on a 18-micron electrolytic copper foil substrate by adopting a plasma cleaning machine; s2, the surface of the copper foil is coated with an antioxidant, and the antioxidant is composed of 10% of alkyl benzimidazole, 5% of polyvinyl alcohol, 3% of gallic acid, 2% of triethanolamine and 1% of octylphenol polyoxyethylene ether; plasma cleaning is adopted to replace traditional chemical cleaning, the surface cleanliness of the substrate and the adhesive force of a coating are remarkably improved, a dense protective film is formed through a multi-component antioxidant, the corrosion resistance is enhanced, ultraviolet laser drilling is matched with ultrasonic cleaning, the hole wall quality is improved, internal drilling dirt is avoided, the layering risk is reduced, and the service life of the substrate is prolonged. The pulse electroplating hole filling technology optimizes the current density and the electroplating liquid components, improves the hole filling compactness and the conductive reliability, and further comprehensively improves the precision and the dimensional stability of the circuit board manufactured by the technology.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of circuit processing, in particular to a preparation process of a circuit board. BACKGROUND

[0002] The manufacturing process of the traditional circuit board can be restructured into the following systematic process: first, the substrate pretreatment link is carried out, the surface of the copper foil substrate is subjected to deep purification by acid or alkaline chemical cleaning process, impurities are removed and the surface activity is optimized; then the anti-oxidation protective layer is constructed, a single-component chemical coating technology is used to form a dense protective film on the copper surface, which effectively blocks the environmental oxidation factors; then the micro-hole processing stage is entered, the precise forming of blind holes is realized by using precision mechanical drilling equipment; then the electroplating hole filling operation is carried out, the metal filling in the hole is carried out by using direct current electroplating process, and a continuous conductive layer is formed; in the pattern forming link, ultraviolet light exposure and chemical development technology are applied to complete pattern transfer, and the accurate transfer of the design pattern is realized through the photochemical reaction of photosensitive materials; finally, the etching process is carried out, efficient chemical etching liquid such as ferric chloride is selected to selectively etch the non-pattern area, and the redundant copper layer is accurately stripped, and finally the complete circuit pattern structure is formed. The whole process is combined through physical-chemical process, realizes the controllable manufacturing from substrate pretreatment to finished product pattern, and ensures that the circuit board meets the requirements of conductive performance, weather resistance and dimensional accuracy and other multi-dimensional technical indicators.

[0003] The traditional process has obvious shortcomings in many key links. First, the chemical cleaning cannot completely remove the oxides and organic residues on the surface of the substrate, the residual chemical agents cause the decrease of the coating adhesion, and affect the circuit forming quality, second, the single-component anti-oxidation layer has insufficient corrosion resistance, it is difficult to form a durable and stable protective film, the copper foil is easily oxidized during long-term use, the service life is shortened, in addition, mechanical drilling is easy to cause high roughness of hole wall, poor hole type perpendicularity and residual drilling dirt, which further increases the possibility of interlayer separation, direct current electroplating hole filling is easy to produce hole and surface depression, the filling hole light transmission uniformity is only 90%, and the reliability of interconnection is reduced. SUMMARY

[0004] The present application aims to provide a preparation process of a circuit board to solve the problems raised in the background.

[0005] To achieve the above-mentioned purpose, the present application provides the following technical scheme: a preparation process of a circuit board, the process method comprising the following steps: Step S1, using a plasma cleaning machine to treat the surface of an 18μm electrolytic copper foil substrate; Step S2, coating an antioxidant on the surface of the copper foil, the antioxidant is composed of alkyl benzimidazole 10%, polyvinyl alcohol 5%, gallic acid 3%, triethanolamine 2% and octylphenol polyoxyethylene ether 1%, and after coating, it is cured at 120℃ for 20min. Step S3, using a UV laser to drill blind holes, the hole diameter is 50±2 μm, the drilling depth is controlled at 100±5 μm, and the hole wall perpendicularity is ≤88°; Step S4, filling the blind hole with electroplating in an electroplating tank, the electroplating liquid system is composed of CuSO450 g / L, H2SO4200 g / L and 5 g / L of additives; Step S5, after electroplating, using a multi-layer hot press to press the epoxy resin film on the copper-clad plate; Step S6, using a UV exposure machine to transfer the circuit pattern, wherein the developing solution used is 0.5% Na2CO3 solution, and after development, the sample is treated by deionized water spray washing and nitrogen knife drying; Step S7, using an etching machine to etch the circuit, and the etching liquid composition is FeCl3400 g / L; Step S8, after the etching process, the resist photoresist is removed, and a 40 kHz ultrasonic wave generating system is used to generate cavitation effect, and after the film is removed, the sample is treated by water washing and drying to obtain a circuit board.

[0006] Preferably, in the step S1, the equipment parameters of the plasma cleaning machine are set as power 200 W, processing time 5 min, and vacuum degree ≤5×10 - ³ Pa.

[0007] Preferably, in the step S1, the surface roughness Ra of the substrate after treatment is controlled in the range of 0.15-0.45 μm.

[0008] Preferably, in the step S2, the spin coating parameters during coating are set as rotation speed 3000 rpm and spin coating time 30 seconds to form a uniform coating with a thickness of 2 μm, the coating process is carried out in a hundred-level clean room, the environmental temperature is controlled at 25±2 ℃, and the relative humidity is ≤50%, and after coating, the sample is cured at 120 ℃ for 20 min.

[0009] Preferably, in the step S3, the laser parameters are set as wavelength 355 nm, power 5 W, frequency 20 kHz, and pulse width 200 ns.

[0010] Preferably, in the step S4, the additives contain brightener and leveling agent, the current density during electroplating is set as 2 A / dm², the electroplating time is 30 minutes, and the liquid temperature is controlled at 25±1 ℃.

[0011] Preferably, in the step S5, the hot pressing parameters are set as temperature 180 ℃, system pressure 5 MPa, time duration 10 min, epoxy resin film thickness 30 μm, glass transition temperature Tg≥150 ℃, and dielectric constant ≤4.0.

[0012] Preferably, in the step S6, the exposure parameter is set as wavelength 365 nm, exposure time 10 seconds, and energy density 20 mJ / cm².

[0013] Preferably, in the step S7, the temperature during etching is 40℃, and the etching time is 120 seconds.

[0014] Preferably, in the step S8, the film removing solution is N-methyl pyrrolidone.

[0015] Compared with the prior art, the present application has the following advantages: The present application uses plasma cleaning instead of traditional chemical cleaning, significantly improves the substrate surface cleanliness and coating adhesion, and forms a dense protective film through multi-component antioxidant to enhance corrosion resistance. Ultraviolet laser drilling combined with ultrasonic cleaning improves the quality of the hole wall, avoids internal drilling pollution, reduces the risk of delamination, and optimizes the current density and plating solution composition through pulse plating hole filling technology to improve the hole filling density and conductive reliability. Thus, the precision and dimensional stability of the circuit board prepared by the process are comprehensively improved, solving the problems of high hole wall roughness, many hole filling defects, and poor circuit precision in traditional processes. DETAILED DESCRIPTION

[0016] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the embodiments in the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0017] A preparation process of a circuit board, which includes the following steps: Step S1: using a plasma cleaning machine to perform surface treatment on an 18 μm electrolytic copper foil substrate, and setting the equipment parameters as power 200 W, treatment time 5 min, and vacuum degree ≤5×10 - ³Pa. The copper foil needs to be cleaned by ultrasonic cleaning with deionized water for 3-5 min to remove surface impurities. A two-stage vacuum system composed of a vortex molecular pump and a mechanical pump is used to maintain a high vacuum environment in the cavity. Ar ions excited by a high-frequency electric field are used to bombard the substrate surface with a kinetic energy of 500-800 eV, so that the surface layer oxides and organic residues are physically sputtered and chemically dissociated. After treatment, the surface roughness Ra of the substrate needs to be controlled in the range of 0.15-0.45 μm. After the step S1, contact angle test (≤30°) and surface tension test (≥38 mN / m) are performed to ensure the coating adhesion. This step is different from the traditional chemical cleaning process, which realizes more thorough surface cleaning through physical bombardment, improves the subsequent coating bonding strength, and reduces the circuit manufacturing defect rate. Step S2, using a spin coater on the surface of the copper foil coated with antioxidant, spin coating parameters are set to 3000 rpm, 30 seconds, forming a uniform coating thickness of 2 μm, antioxidant consists of alkyl benzimidazole 10%, polyvinyl alcohol 5%, gallic acid 3%, triethanolamine 2% and octylphenol polyoxyethylene ether 1%, using green glue dandelion root polyphenol and formaldehyde reaction to form a self-assembly network structure, coating process in a hundred clean room, the ambient temperature is controlled at 25±2℃, relative humidity ≤50%, after coating 120℃ stepwise temperature curing 20 min, the coating through the polyphenol ortho-hydroxyl and copper ion to form a stable chelate structure, and benzimidazole nitrogen atom and copper surface coordination, forming a dense protection film with 98% density, the coating through the polyphenol-metal ion complexation to form a dense protective film, corrosion resistance is improved by 30%, which is different from the traditional single component antioxidant layer; Step S3, using a UV laser to drill blind holes, the laser parameters are set to wavelength 355 nm, power 5 W, frequency 20 kHz, pulse width 200 ns, a focused spot with a diameter of 50±2 μm is obtained through a beam shaping system, the drilling diameter is 50±2 μm, the drilling depth is controlled at 100±5 μm, the hole wall perpendicularity is ≤88°, the drilling process is combined with a high-precision XY platform (positioning accuracy ±2 μm), the pulse laser ablation and ion cutting composite technology is used to reduce the hole wall roughness and layering risk, after drilling, 40 kHz ultrasonic waves are used in ethanol solution for 180 seconds to completely remove the residues in the hole, and the hole morphology is detected by three-dimensional reconstruction of field emission scanning electron microscopy, this technology realizes high-precision hole site control, which is different from the traditional mechanical drilling process; Step S4, blind hole filling electroplating is carried out in an electroplating tank, the electroplating liquid system is composed of CuSO450 g / L, H2SO4200 g / L and additives 5 g / L, wherein the additives contain brightener and leveling agent, the current density is set to 2 A / dm², the electroplating time is 30 minutes, the liquid temperature is controlled at 25±1℃, the pulse power source is used to realize non-gap hole filling, the duty cycle of the pulse power source is 50%, and the power frequency is 100 Hz, the diffusion layer thickness in the hole is reduced by 60% through periodic reverse current, realizing the effect of ultra-equiaxed deposition, after hole filling, the substrate is subjected to backlight detection and cross-section analysis to ensure no gap and depression, this process improves the conduction reliability by optimizing the current density and electroplating liquid composition; Step S5, using a multi-layer hot press to press the copper-clad plate with epoxy resin film, the hot pressing parameters are set as temperature 180℃, system pressure 5MPa, time duration 10min, epoxy resin film thickness 30μm, glass transition temperature Tg≥150℃, dielectric constant ≤4.0, the pressing process adopts vacuum film pressing technology, the thermal stability of the system is enhanced by using nano-aluminum oxide ceramic-based modifier, the vacuum film pressing technology is realized by using a two-stage vacuum system with an ultimate vacuum degree ≤0.1Pa, the three-parameter closed-loop control of pressure-temperature-vacuum degree is used to ensure that there is no air bubble and delamination between the layers, and the thickness measurement (thickness deviation ≤±3%) and 90° peeling strength test (≥1.5N / mm) after pressing are required, the modified resin system prolongs the heat resistance time of the circuit board to 180 seconds in the 260℃ soldering immersion test; Step S6, using an ultraviolet exposure machine to transfer the circuit pattern, the exposure parameters are set as wavelength 365nm, exposure time 10 seconds, and energy density 20mJ / cm², the developing solution used is 0.5% Na2CO3 solution, the liquid temperature is controlled at 30±1℃, the developing time is 60s, the developing end point is controlled by an online film thickness monitoring system, after developing, deionized water is sprayed for rinsing and nitrogen knife drying treatment, and the optical microscope equipped with a CCD measurement system is used to check the circuit morphology, the whole exposure and developing process is carried out in a Class1000 yellow light room, sodium lamp illumination is used to avoid natural light interference, and this process can realize the production of fine circuits with line width / line spacing 50±5μm, and the key size uniformity is controlled within ±3%; Step S7, using an etching machine to etch the circuit, the etching liquid composition is FeCl3400g / L, the temperature is 40℃, and the etching time is 120 seconds, the spraying pressure is stabilized at 0.2MPa by frequency control, the etching process adopts a spraying system to ensure uniformity, after etching, the residual etching liquid is removed by water washing and acid washing, and the circuit width measurement and side etching detection are required after etching, this process reduces the side etching phenomenon and improves the circuit precision by optimizing the etching liquid concentration and temperature; Step S8, after the etching process is completed, the resist photoresist is removed, a full-automatic film removing machine is used, the main component of the film removing liquid is N-methyl pyrrolidone (NMP), the operating temperature is 60±5℃, the processing time is 5 minutes, the cavitation effect is generated by a 40kHz ultrasonic wave generating system, the film removing process adopts ultrasonic wave assistance to ensure that the photoresist is completely removed, after film removing, water washing and drying treatment are required, and the surface inspection is used to confirm that there is no residual photoresist, this step uses an environmentally friendly film removing liquid to reduce environmental pollution and improve the process sustainability, and a circuit board is prepared.

[0018] Example one: A preparation process of a circuit board, the process method comprises the following steps: Step S1, the surface of the 18 μm electrolytic copper foil substrate is treated by a plasma cleaning machine, the equipment parameters are set as power 200 W, treatment time 5 min, vacuum degree ≤5×10⁻³ Pa, the copper foil is cleaned by ultrasonic cleaning with deionized water for 4 min to remove surface impurities, the surface roughness Ra of the treated substrate is 0.35 μm, and the contact angle test (28°) and surface tension test (40 mN / m) are performed; Step S2, an antioxidant is coated on the surface of the copper foil using a spin coater, the spin coating parameters are set as rotation speed 3000 rpm, leveling time 30 seconds, a uniform coating with a thickness of 2 μm is formed, the antioxidant composition is shown in the following table; the coating process is carried out in a hundred-level clean room, the environmental temperature is controlled at 25°C, the relative humidity is 45%, after coating, it is cured at 120°C for 20 min by stepwise heating; Table 1, antioxidant composition table in example one Step S3, blind hole drilling is performed using a ultraviolet laser, the laser parameters are set as wavelength 355 nm, power 5 W, frequency 20 kHz, pulse width 200 ns, drilling diameter 50 μm, drilling depth 100 μm, hole wall perpendicularity 87°, after drilling, the hole residue is removed by 40 kHz ultrasonic cleaning in ethanol solution for 180 seconds; Step S4, blind hole filling plating is carried out in an electroplating tank, the electroplating liquid system is composed of CuSO450 g / L, H2SO4200 g / L and additive 5 g / L, the current density is set as 2 A / dm², the electroplating time is 30 minutes, the liquid temperature is controlled at 25°C, a pulse power source is used, the duty cycle is 50%, the frequency is 100 Hz, after filling, the substrate is subjected to backlight detection (transmittance uniformity 96%); Step S5, the copper-clad plate is pressed with epoxy resin film using a multi-layer hot press, the hot pressing parameters are set as temperature 180°C, system pressure 5 MPa, time 10 min, the thickness of the epoxy resin film is 30 μm, the pressing process uses a two-stage vacuum system (limiting vacuum degree 0.08 Pa); Step S6, line pattern transfer is carried out using a ultraviolet exposure machine, the exposure parameters are set as wavelength 365 nm, exposure time 10 seconds, energy density 20 mJ / cm², 0.5% Na2CO3 solution is used for development, liquid temperature 30°C, development time 60 s; Step S7, line etching is carried out using an etching machine, the etching liquid composition is FeCl3400 g / L, the temperature is 40°C, the etching time is 120 seconds, the spraying pressure is 0.2 MPa; Step S8, after the etching process is completed, the resist photoresist is removed, a full-automatic film removal machine is used, the film removal liquid is N-methyl pyrrolidone (NMP), the temperature is 60°C, the time is 5 minutes, after film removal, water washing and drying treatment are carried out, a circuit board is prepared.

[0019] Example 2: Compared with Example 1, this example differs only in step S2, as follows: Step S2: The antioxidant components are adjusted as follows, and the coating and curing parameters are the same as in Example 1.

[0020] Table 2. Antioxidant Components in Example 2 Example 3: Compared with Example 1, this example differs only in step S2, as follows: Step S2: The antioxidant components are adjusted as follows (as shown in Table 3), and the coating and curing parameters are the same as in Example 1.

[0021] Table 3. Antioxidant Components in Example 3 Example 4: Compared with Example 1, this example differs only in step S4, as follows: Step S4: Perform blind hole filling electroplating in the electroplating tank. The electroplating solution system consists of CuSO4 55g / L, H2SO4 180g / L and additives 6g / L. The current density is set to 2.2A / dm², the electroplating time is 28 minutes, the liquid temperature is controlled at 26℃, a pulse power supply is used with a duty cycle of 55% and a frequency of 90Hz. The remaining steps and parameters are the same as in Example 1. This example mainly optimizes the electroplating filling step by increasing the main salt concentration and current density, aiming to improve the deposition rate and production efficiency, as shown in the table below.

[0022] Table 4, Process Parameter Adjustment Table for Example 4 Example 5: Compared with Example 1, this example differs only in step S4, as follows: Step S4: Perform blind hole filling electroplating in the electroplating tank. The electroplating solution system consists of CuSO4 45g / L, H2SO4 220g / L and additives 4g / L. The current density is set to 1.8A / dm², the electroplating time is 32 minutes, the liquid temperature is controlled at 24℃, a pulse power supply is used with a duty cycle of 45% and a frequency of 110Hz. The remaining steps and parameters are the same as in Example 1. This example also optimizes the electroplating steps, but in the opposite direction to Example 4. By reducing the concentration and current density, the aim is to obtain a finer grain structure and better deep hole dispersion ability, as shown in the table below.

[0023] Table 5. Adjustment Table of Process Parameters in Example 5 Example Six: Compared with Example One, this example only has differences in step S6, as follows: Step S6, line pattern transfer is performed using an ultraviolet exposure machine, the exposure parameter is set to wavelength 365 nm, exposure time 12 seconds, energy density 22 mJ / cm2, 0.6% Na2CO3 solution is used for development, liquid temperature 32°C, development time 55 seconds, the remaining steps and parameters are the same as Example One. This example mainly adjusts the pattern transfer process, by increasing the exposure energy and the development liquid concentration, aiming to adapt to thicker or more difficult-to-develop resist, refer to the following table.

[0024] Table 6, process parameter adjustment table of Example Six Example Seven: Compared with Example One, this example only has differences in step S6, as follows: Step S6, line pattern transfer is performed using an ultraviolet exposure machine, the exposure parameter is set to wavelength 365 nm, exposure time 8 seconds, energy density 18 mJ / cm2, 0.4% Na2CO3 solution is used for development, liquid temperature 28°C, development time 65 seconds, the remaining steps and parameters are the same as Example One. This example also adjusts the pattern transfer process, but uses more moderate exposure and development conditions, aiming to reduce lateral corrosion and obtain more precise line width control.

[0025] Table 7, process parameter adjustment table of Example Seven Through these tables, it can be seen intuitively that Examples Four and Five are two directions of exploration in plating performance (efficiency and quality), while Examples Six and Seven are different strategies for optimizing pattern transfer precision (development intensity and line width control).

[0026] Performance comparison test: Samples are taken from the line boards made in the traditional process line, Example One to Example Seven, respectively, for key performance testing, the test content includes the following: Coating adhesion test: use crosshatch knife to draw grid, paste with 610 heat-resistant light packaging tape, then tear off at 90° angle quickly, calculate the percentage of coating falling area.

[0027] Hole wall quality detection: use scanning electron microscope to measure hole wall roughness (Rz).

[0028] Line precision detection: use automatic optical detection equipment to measure line width, and calculate the deviation from the design value.

[0029] Plating filling quality: The filling uniformity was evaluated by backlight detection, and the voids in the hole were evaluated by slice analysis. The experimental results are shown in the following table: Table 8, Comparison table of test results of products prepared in each example According to the experimental comparison, example one shows excellent performance in multiple dimensions such as adhesion, hole wall quality, line precision and filling quality, and has the best overall performance; example two maintains a high level of adhesion by increasing the content of alkyl benzimidazole; example three slightly reduces the adhesion after reducing the component, verifying its role as a key factor affecting adhesion; example four improves the plating solution concentration and current density, and the filling density is slightly improved; example five reversely adjusts and results in a slight decrease in density; examples six and seven adjust the exposure and development parameters, which have limited impact on adhesion and hole quality, but the line width deviation increases significantly, highlighting the sensitivity of the pattern transfer link to line precision, and finally confirming that the parameter combination of example one is the best balanced solution, achieving comprehensive optimization of performance.

[0030] It should be noted that, in this document, relational terms such as first and second and the like can be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises", "comprising", or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without limitation, an element preceded by "comprises... a" does not, without more constraints, foreclose the existence of additional identical elements in the process, method, article, or apparatus.

[0031] Although embodiments of the present application have been shown and described, it is to be understood that various modifications, substitutions, replacements and changes can be made to these embodiments without departing from the principles and spirit of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A process for producing a wiring board, characterized by, The process method comprises the following steps: Step S1, using a plasma cleaning machine to perform surface treatment on an 18 μm electrolytic copper foil substrate; Step S2, coating an antioxidant on the surface of the copper foil, the antioxidant being composed of 10% alkyl benzimidazole, 5% polyvinyl alcohol, 3% gallic acid, 2% triethanolamine and 1% octylphenol polyoxyethylene ether, and after coating, curing at 120°C for 20 min by stepwise temperature rise; Step S3, using a UV laser to perform blind hole drilling, the drilling diameter being 50±2 μm, the drilling depth being controlled at 100±5 μm, and the hole wall perpendicularity being ≤88°; Step S4, performing blind hole filling plating in an electroplating tank, the electroplating liquid system being composed of CuSO450 g / L, H2SO4200 g / L and 5 g / L of an additive; Step S5, using a multilayer hot press to press the epoxy resin film after electroplating; Step S6, using a UV exposure machine to perform circuit pattern transfer, wherein the developing solution used is 0.5% Na2CO3 solution, and after developing, deionized water is sprayed for rinsing and nitrogen knife drying treatment; Step S7, using an etching machine to perform circuit etching, the etching liquid composition being FeCl3400 g / L; Step S8, removing the etching resist photoresist after the etching process is completed, cooperating with a 40 kHz ultrasonic wave generating system to generate cavitation effect, and after film removal, water washing and drying treatment are required, thereby obtaining a circuit board.

2. The process for manufacturing a circuit board according to claim 1, wherein: The equipment parameters of the plasma cleaning machine in step S1 are set as power 200 W, processing time 5 min, and vacuum degree ≤5×10 - ³ Pa.

3. The process for manufacturing a circuit board according to claim 1, wherein: In the step S1, the substrate surface roughness Ra after treatment is controlled in the range of 0.15-0.45 μm.

4. The process for manufacturing a circuit board according to claim 1, wherein: In the step S2, the spin coating parameters are set to 3000 rpm during coating, the spin coating time is 30 seconds, a uniform coating with a thickness of 2 μm is formed, the coating process is carried out in a hundred-level clean room, the environmental temperature is controlled at 25±2°C, and the relative humidity is ≤50%, and after coating, curing at 120°C for 20 min by stepwise temperature rise.

5. The process for manufacturing a circuit board according to claim 1, wherein: In the step S3, the laser parameters are set as follows: wavelength 355 nm, power 5 W, frequency 20 kHz, and pulse width 200 ns.

6. The process for manufacturing a circuit board according to claim 1, wherein: In the step S4, the additive contains brightener and leveling agent, the current density during electroplating is set to 2 A / dm2, the electroplating time is 30 minutes, and the liquid temperature is controlled at 25±1°C.

7. The process for manufacturing a circuit board according to claim 1, wherein: In the step S5, the hot pressing parameters are set as follows: temperature 180°C, system pressure 5 MPa, time duration 10 min, epoxy resin film thickness 30 μm, glass transition temperature Tg≥150°C, and dielectric constant ≤4.

0.

8. The process for manufacturing a circuit board according to claim 1, wherein: In the step S6, the exposure parameters are set as follows: wavelength 365 nm, exposure time 10 seconds, and energy density 20 mJ / cm2.

9. The process for manufacturing a circuit board according to claim 1, wherein: In the step S7, the temperature during etching is 40°C, and the etching time is 120 seconds.

10. The process for manufacturing a circuit board according to claim 1, wherein: In the step S8, the film removal liquid composition is N-methyl pyrrolidone.

Images