Baking-free printed circuit board manufacturing method and device and use method of device

Abstract

The invention relates to a printed circuit board coating technology, in particular to a baking-free printed circuit board manufacturing method, a baking-free printed circuit board manufacturing device and an application method of the baking-free printed circuit board manufacturing device. The method aims at solving the problems that in the prior art, a PCB manufacturing process is complex, baking is needed, precision is limited, and cost is high. The core of the technical scheme is that after the surface of the copper-clad plate is coated with a layer of baking-free photosensitive resin, a direct imaging device is adopted to selectively expose the photosensitive resin layer according to digital circuit pattern data so as to form a cured circuit pattern, and then the steps of cleaning, etching and removing the cured resin are sequentially carried out. For a double-sided board, the alignment of double-sided patterns is realized through the positioning holes. According to the invention, the direct imaging technology is combined with the photosensitive resin, so that a physical mask and all baking procedures are thoroughly omitted, the manufacturing process is greatly simplified, the production efficiency, the precision and the yield are remarkably improved, the energy consumption and the production cost are reduced, and the production flexibility is enhanced.

Description

TECHNICAL FIELD

[0001] The present application relates to printed circuit board coating technology, in particular to a baking-free printed circuit board manufacturing method, device and method of using the device. BACKGROUND

[0002] Printed circuit board (PCB) is an indispensable basic component in modern electronic equipment, which provides mechanical support and electrical connection for electronic components. The traditional PCB pattern transfer process mainly relies on photolithography technology based on physical mask (usually called film or negative). A typical traditional PCB manufacturing process usually contains the following cumbersome steps: first, according to the circuit design data (such as Gerber file), a high-precision master mask is made; then, in order to protect the expensive master mask, a number of working masks are copied for daily production. In the pattern transfer stage, a layer of liquid photoresist or a layer of dry film photoresist is coated on the pretreated copper-clad plate. In order to enhance the adhesion and stability of the photoresist, pre-baking process is usually required before and after coating or pressing. Then, the working mask is accurately covered on the copper-clad plate coated with photoresist, and contact or close-range exposure is carried out by ultraviolet light. After exposure, post-baking process is required to stabilize the pattern. Finally, through the steps of developing, etching, and film removing, the circuit pattern is completed.

[0003] This traditional manufacturing method has the following inherent defects, which seriously restricts the efficiency, accuracy and cost-effectiveness of PCB manufacturing: (1) complex process, long cycle: the process of making master mask and working mask itself is time-consuming and costly, which increases the preparation time and management complexity of production. (2) High energy consumption and low efficiency of baking process: pre-baking and post-baking processes not only consume a large amount of electric energy and occupy valuable factory space, but also significantly prolong the entire manufacturing cycle. At the same time, high-temperature baking may introduce thermal stress to some sensitive substrates (especially flexible substrates), causing plate deformation and affecting the quality of the final product. (3) Defects and precision limitations introduced by physical mask: physical mask is easily worn, scratched or contaminated by dust particles during storage, handling and use, and these defects will be directly copied to PCB, causing open circuit or short circuit of the circuit, thereby reducing the production yield. (4) Poor production flexibility and high cost: for small batch and multi-species production demand, each time the product model is changed, a new set of mask needs to be made, which not only costs high, but also has slow response speed, which cannot adapt to the trend of rapid prototyping and flexible production. SUMMARY

[0004] The present application aims to overcome the technical problems of complex manufacturing process, time-consuming and energy-consuming baking process, limited precision due to reliance on physical mask, low yield and high production cost in the existing PCB manufacturing, and to provide a printed circuit board manufacturing method with simplified process, high precision, no baking and strong production flexibility, as well as a device thereof and a use method of the device.

[0005] To achieve the above-mentioned purpose, the present application provides a manufacturing method of a single-sided printed circuit board, after pretreatment of a copper-clad plate, the core steps of which include: a1) providing a copper-clad plate, and brushing and cleaning the copper-clad plate for pretreatment; b1) drilling the copper-clad plate to form plug-in holes and positioning holes; c1) coating a photosensitive material on the surface of the copper foil of the copper-clad plate to form a photosensitive resin layer; d1) using a direct imaging device to selectively expose the photosensitive resin layer according to preset digital circuit pattern data, and forming a solidified circuit pattern on the resin layer; e1) cleaning and removing the photosensitive resin in the unexposed area to expose the copper foil thereunder; f1) etching the exposed copper foil; g1) removing the solidified circuit pattern to obtain a final printed circuit board.

[0006] In another aspect, the present application also provides a manufacturing method of a double-sided printed circuit board, after pretreatment of a double-sided copper-clad plate, the core steps of which include: a2) providing a double-sided copper-clad plate, and brushing and cleaning the double-sided copper-clad plate for pretreatment; b2) drilling the double-sided copper-clad plate to form metallized holes and non-metallized positioning holes; c2) performing copper deposition on the hole wall of the metallized hole; d2) coating a photosensitive resin on the front and back surfaces of the double-sided copper-clad plate respectively to form a photosensitive resin layer; e2) using a direct imaging device to selectively expose the photosensitive resin layer on the front surface according to first preset digital circuit pattern data, and forming a solidified circuit pattern on the resin layer; f2) flipping the double-sided copper-clad plate, and after alignment based on the non-metallized positioning hole in the drill hole, selectively exposing the photosensitive resin layer on the back surface according to second preset digital circuit pattern data to form a solidified circuit pattern on the resin layer; g2) cleaning and removing the photosensitive resin in the unexposed area to expose the copper foil thereunder; h2) etching the exposed copper foil; i2) removing the solidified circuit pattern to obtain a final double-sided printed circuit board.

[0007] The present application provides a manufacturing method of printed circuit board, which fundamentally innovates the traditional pattern transfer process by combining direct imaging lithography technology with photosensitive resin. By using photosensitive resin as photoresist, the pre-baking and post-baking procedures which are indispensable in traditional process are completely eliminated, and the production of physical mask, replication, storage and management are completely abandoned. This makes the steps of the entire pattern transfer process reduced by more than 50%, the production cycle is greatly shortened, and the output per unit time is greatly improved.

[0008] The present application creatively simplifies the original multiple steps of making a master plate, copying a work negative, film pressing, baking, alignment and exposure into two core steps of coating and direct imaging exposure, greatly optimizing the production process and saving time.

[0009] Further, the removal of the solidified circuit pattern refers to immersing or spraying the exposed copper-clad plate in an organic solution or pure water at room temperature according to the properties of the selected photosensitive resin for development treatment.

[0010] The copper-clad plate is cleaned with a cleaning (developing) solution to dissolve and remove the unexposed and uncured photosensitive resin, thereby exposing the underlying copper foil; the exposed copper foil is etched away using a chemical etching solution; finally, the solidified photosensitive resin as an etching-resistant layer is removed using an adhesive or a film-removing solution to obtain a final printed circuit board.

[0011] The thickness of the photosensitive resin layer is in the range of 5-40 microns.

[0012] The direct imaging device is a digital light processing projection device or a laser scanning device using laser or LED with a wavelength range of 250-420 nm as light source to project a selective ultraviolet gray-scale image. The direct imaging device directly reads the preset digital circuit pattern data (such as Gerber file) and performs high-precision and selective exposure on the photosensitive resin layer through a digital light processing projection (DLP) device with digital micromirror device (DMD) or scanning laser, etc., so that the photosensitive resin layer is cured by polymerization reaction in the exposed area to form a mask layer of circuit pattern.

[0013] The photosensitive resin is composed of resin monomer, oligomer, diluent and photoinitiator, and can cause polymerization reaction under ultraviolet light irradiation with a wavelength of 250-420 nm to form an insoluble coating film.

[0014] In step f2) of the manufacturing method of the double-sided printed circuit board, the turning process can also be replaced by adding a direct imaging device below the double-sided copper-clad plate to expose it. The digital circuit pattern data is in the Gerber, BMP or PNG format.

[0015] A non-baking printed circuit board manufacturing device for implementing the above method, mainly used for coating and line imaging in the circuit board manufacturing process, other pre-treatment, drilling, etching and other steps use conventional equipment, the key points are as follows: it comprises a direct imaging device, a copper-clad plate fixing platform, a roller coating mechanism, an X-axis linear motion mechanism, an X-axis linear motion mechanism controller, a lifting mechanism, a lifting mechanism controller, an upper PC, a fixed side plate and a device base, wherein the fixed side plate is fixedly connected with the device base, and the lifting mechanism is fixedly installed on the fixed side plate; the X-axis linear motion mechanism is installed on the device base and controlled by the X-axis linear motion mechanism controller; the copper-clad plate fixing platform is used for fixing the copper-clad plate and is connected to the lifting mechanism, and is driven by the lifting mechanism to move up and down along the fixed side plate; the roller coating mechanism is arranged on the X-axis linear motion mechanism and reciprocally moves along the upper surface of the copper-clad plate fixing platform under the driving of the X-axis linear motion mechanism, so that the roller coating mechanism rolls on the surface of the copper-clad plate; the direct imaging device is suspendedly fixed above the copper-clad plate fixing platform and is used for exposing the coated copper-clad plate; and the upper PC is electrically connected with the X-axis linear motion mechanism controller, the lifting mechanism controller and the direct imaging device respectively and is used for controlling the components to work cooperatively.

[0016] The device is made into an integrated desktop device, the fixed side plate, the device base, the lifting mechanism, the copper-clad plate fixing platform, the roller coating mechanism and the direct imaging device are integrated in the same housing, and the upper PC is configured to directly control the exposure operation after the coating operation is completed without executing a baking program in between.

[0017] The use method of the non-baking printed circuit board manufacturing device is characterized in that the working steps are as follows: 1) The upper PC is used to connect the direct imaging device, the X-axis linear motion mechanism controller and the lifting mechanism controller, and the copper-clad plate to be processed is fixed on the copper-clad plate fixing platform; 2) The lifting mechanism drives the copper-clad plate fixing platform to rise to a set coating height at which the roller coating mechanism works; 3) The X-axis linear motion mechanism is driven by the X-axis linear motion mechanism controller to drive the roller coating mechanism to reciprocally move, and the roller coating mechanism rolls on the surface of the copper-clad plate to form a uniform photosensitive material film; 4) The lifting mechanism drives the copper-clad board fixed platform to rise to the exposure height of the set imaging distance of the direct imaging device; 5) The direct imaging device selectively exposes the photosensitive material film on the surface of the copper-clad board to form a solidified circuit pattern 6) The lifting mechanism drives the copper-clad board fixed platform to descend to the initial position.

[0018] The technical solution provided by the present application has the following remarkable beneficial effects: (1) The process is extremely simplified, and the production efficiency is significantly improved: the present application completely eliminates the production, replication, storage and management of physical masks. More importantly, by using photosensitive resin as a photoresist, the necessary pre-baking and post-baking processes in traditional processes are completely eliminated. This makes the steps of the entire pattern transfer process reduced by more than 50%, the production cycle is greatly shortened, generally 15%-25% time is saved, and the output (throughput) per unit time is greatly improved. (2) Cost reduction and energy saving: first, the production and maintenance costs of the mask are eliminated, which is particularly economically advantageous for small batches and multiple varieties of orders. Second, the elimination of the baking process not only saves the huge capital expenditure for purchasing and maintaining baking equipment, but also significantly reduces energy consumption during the production process, in line with the industrial development direction of green manufacturing. In addition, the utilization rate of factory space is also improved, as there is no longer a need to reserve space for large baking equipment. (3) Precision and yield are greatly improved: direct imaging technology uses digital masks, avoiding problems such as wear and tear and contamination of physical masks, eliminating circuit defects caused by such defects from the source. Its non-contact exposure feature also avoids damage that may be caused by contact between the mask and the substrate. This method can stably achieve the manufacture of fine lines of 10 microns or more, meeting the needs of high-end electronic products. (4) Highly flexible production and rapid response: replacing circuit patterns only requires loading a new digital file into the direct imaging device, without any physical preparation, achieving true "what you see is what you get". This makes it easy for this method to adapt to rapid prototyping, customized production and frequent design changes, greatly enhancing the market competitiveness of enterprises. (5) Full-process automation: the method of the present application is digitized and simplified, and the connection between various processes (such as coating, exposure, development and etching) is very clear, making it easy to integrate with automatic feeding and unloading systems (such as Z-axis platforms), online detection systems, etc., laying a solid technical foundation for building an unmanned and intelligent PCB manufacturing plant. (6) Wide applicability: the non-contact exposure feature makes it not only suitable for traditional rigid copper-clad boards (such as FR-4), but also for flexible substrates (such as polyimide film) and special-shaped substrates that are more sensitive to mechanical and thermal stress, broadening the application range of the technology. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is a flow chart of the single-sided printed circuit board manufacturing method in the embodiment 1 of the present application.

[0020] Figure 2 is a flow chart of the double-sided printed circuit board manufacturing method in the embodiment 2 of the present application.

[0021] Figure 3 is a schematic cross-sectional view of the direct imaging exposure step in the present application.

[0022] Figure 4 is a cross-sectional view of the double-sided copper-clad plate when the partially exposed photosensitive resin is cured in the present application.

[0023] Figure 5 is a cross-sectional view of the copper-clad plate after the uncured photosensitive resin is washed and dissolved in the present application.

[0024] Figure 6 is a cross-sectional view of the plate after the exposed copper foil is etched in the present application.

[0025] Figure 7 is a cross-sectional view of the printed circuit board after the cured photosensitive resin is stripped in the present application.

[0026] Figure 8 is a structural block diagram of the baking-free printed circuit board manufacturing device in the present application.

[0027] Figure 9 is a schematic diagram of the coating operation using the baking-free printed circuit board manufacturing device in the present application Figure 10 is a schematic diagram of the exposure operation using the baking-free printed circuit board manufacturing device in the present application BRIEF DESCRIPTION OF DRAWINGS 301 - laser / LED UV light source, 302 - photosensitive resin, 303 - copper foil, 304 - substrate; 401 - uncured photosensitive resin, 402 - cured photosensitive resin; 1 direct imaging device, 2 copper-clad plate fixing platform, 3 roller coating mechanism, 4 X-axis linear motion mechanism, 5 X-axis linear motion mechanism controller, 6 lifting mechanism, 7 lifting mechanism controller, 8 upper PC, 9 fixed side plate, 10 device base. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of 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 a person of ordinary skill in the art without creative labor fall within the protection scope of the present application.

[0029] Example 1: Manufacturing of single-sided printed circuit board Reference Figure 1 The present embodiment provides a method for manufacturing a single-sided printed circuit board, and the specific steps are as follows: S101: Pretreatment. Select a standard FR-4 single-sided copper-clad plate. First, mechanically brush the copper foil surface to remove the surface oxide layer and impurities, and increase the surface roughness, generally the roughness is controlled between 1.5-3.0 microns, to facilitate the subsequent adhesion of photosensitive resin. Then, go through the chemical treatment steps of degreasing, washing, and micro-etching in turn, to ensure the cleanliness of the copper foil surface.

[0030] S102: Drilling. According to the circuit design file, use a numerical control drilling machine to drill the required component mounting holes, vias, and at least two positioning holes for positioning and docking with the direct imaging device on the copper-clad plate.

[0031] S103: Apply photosensitive resin. Place the copper-clad plate that has been pretreated and drilled on a spin coater, and add a UV-curable acrylate-based photosensitive resin. The photosensitive resin in this embodiment is composed of resin monomers, oligomers, diluents, and photoinitiators, and can cause polymerization under UV light irradiation with a wavelength of 250-420 nm to form an insoluble coating film. By spin coating (for example, spin coating at a speed of 1500 rpm for 30 seconds), a uniform thickness of photosensitive resin film is formed on the copper foil surface, forming a photosensitive resin layer, the thickness of the photosensitive resin layer is in the range of 5-40 microns, and the minimum line width of the printed circuit board manufactured by the method for manufacturing a single-sided printed circuit board and the method for manufacturing a double-sided printed circuit board is 10 microns. This method can stably realize the manufacturing of fine lines of 10 microns and above, meeting the needs of high-end electronic products. In this example, the thickness of the photosensitive resin layer is 25±2 microns.

[0032] Silk screen printing, curtain coating, roller coating, or spraying can also be used for coating. After coating, the copper-clad plate does not need to be baked and can be directly transferred to the next process.

[0033] S104: Direct imaging exposure. Refer to Figure 3The copper-clad laminate (CCL) consists of copper foil 303 and a substrate 304. The CCL coated with photosensitive resin 302 is transferred to the working platform of a direct imaging device (e.g., a DLP device based on DMD technology). The device loads a preset Gerber format digital circuit pattern file, or a BMP or PNG format file. The device uses positioning holes on the CCL for precise positioning and calibration. Subsequently, the ultraviolet light source 301 (a laser or LED with a wavelength of 250-420 nm, capable of projecting selective ultraviolet grayscale images; it can also be a laser scanning device; in this example, a laser diode with a wavelength of 405 nm is selected) inside the direct imaging device emits a beam of light that selectively exposes the photosensitive resin (photoresist) 302 according to the preset digital pattern data. In the illuminated area, the photosensitive resin undergoes a photopolymerization reaction and cures, forming a circuit pattern insoluble in the developer. The exposure energy can be set to 50 mJ / cm² to ensure complete resin curing. Figure 4 As shown, uncured photosensitive resin 401 and cured photosensitive resin 402 are formed on the surface of the copper clad laminate.

[0034] S105: Cleaning (Developing). The exposed copper-clad laminate is immersed in or sprayed with an organic solvent (such as 75% alcohol) or purified water at room temperature, depending on the characteristics of the selected photosensitive resin. Figure 5 As shown, the photosensitive resin in the unexposed area (i.e., the uncured photosensitive resin 401) is rapidly dissolved and removed, exposing the copper foil 303 underneath, while the cured photosensitive resin 402 that forms the cured circuit pattern remains on the substrate 304 as a protective layer for subsequent etching.

[0035] S106: Etching. The developed copper-clad laminate is fed into an etching machine, where acidic copper chloride or ferric chloride etching solution is used to etch away the exposed copper foil. The copper foil 303 portion, protected by the cured photosensitive resin 402, is left on the substrate 304 to form the required circuit wires, such as... Figure 6 As shown.

[0036] S107: Removal of photosensitive resin (film removal). Using adhesive or tape, the cured photosensitive resin, which acts as a protective layer, is peeled off to expose the final copper conductor circuitry, forming the desired circuit board. Finally, after cleaning and drying, the finished single-sided printed circuit board is obtained, such as... Figure 7 As shown.

[0037] Example 2: Manufacturing of Double-Sided Printed Circuit Boards Reference Figure 2 This embodiment provides a method for manufacturing a double-sided printed circuit board, the main difference from Embodiment 1 being the addition of copper plating and double-sided alignment exposure steps.

[0038] S201: Pretreatment. Similar to step S101, a double-sided copper-clad plate is selected and pretreated on both sides. First, the copper foil surface is mechanically brushed to remove the surface oxide layer and impurities, and the surface roughness is increased to facilitate the subsequent adhesion of the photosensitive resin. Then, the plate is subjected to chemical treatment steps such as degreasing, washing, and micro-etching to ensure the cleanliness of the copper foil surface.

[0039] S202: Drilling: Similar to 102, a double-sided copper-clad plate is pretreated and drilled on both sides, including metallized holes and non-metallized positioning holes.

[0040] S203: Copper plating. After protection treatment such as hole plugging or masking on non-metallized holes, the drilled copper-clad plate is subjected to full-plate chemical copper plating and pattern electroplating treatment to form a uniform conductive copper layer on the hole wall of the metallized hole, thereby achieving electrical communication of the double-sided circuit.

[0041] S204: Coating photosensitive resin. On the front and back surfaces of the copper-clad plate, a layer of oven-free photosensitive resin is coated in the same manner as step S103 to form a photosensitive resin layer.

[0042] S205: Double-sided direct imaging exposure. First, the first side (front side) of the copper-clad plate is sent into the direct imaging device. The device loads the preset circuit pattern data of the first side, aligns through the non-metallized positioning holes, and then selectively exposes the photosensitive resin layer on the first side to form a solidified circuit pattern on the resin layer. Then, the copper-clad plate is flipped over so that the second side (back side) is facing up. The direct imaging device aligns again through the same set of positioning holes on the copper-clad plate and loads the circuit pattern data of the second side to expose the photosensitive resin layer on the second side, forming a solidified circuit pattern on the resin layer, resulting in a board as shown in Figure 4 . Both sides have un-solidified photosensitive resin 401 and solidified photosensitive resin 402. Alternatively, two direct imaging devices can be used to expose the photosensitive resin layers on both sides of the copper-clad plate simultaneously.

[0043] S206 to S208: Development, etching, and film removal. The subsequent development, etching, and film removal steps are basically the same as steps 105 to 107 in Example 1, except that both sides of the substrate need to be treated simultaneously. Finally, a high-precision double-sided printed circuit board is obtained.

[0044] A oven-free PCB manufacturing device for implementing the above-mentioned embodiment 1 As shown in Figure 8 , the present application provides a desktop PCB manufacturing all-in-one machine. It is mainly used for coating and imaging in the process of circuit board manufacturing, and other pretreatment, drilling, etching, etc. steps use conventional equipment.

[0045] A kind of baking-free printed circuit board manufacturing device for implementing above-mentioned method, and it is made into integrated desktop type equipment, which is mainly composed of rack assembly, motion control assembly, coating assembly and imaging assembly.It includes: direct imaging device 1 (such as DLP projection light machine);Copper-clad plate fixed platform 2 for fixing copper-clad plate;Roller coating mechanism 3, X-axis linear motion mechanism 4;X-axis linear motion mechanism controller 5;Lifting mechanism 6;Lifting mechanism controller 7;Upper PC 8;Fixed side plate 9;Device base 10, fixed side plate, device base, lifting mechanism, copper-clad plate fixed platform, roller coating mechanism and direct imaging device are integrated in the same housing (not shown) inside.

[0046] Wherein, rack and support structure: by a vertical fixed side plate 9 and device base 10, the side plate and base are used as the reference support of Z-axis lifting motion and X-axis motion, with high rigidity, high flatness, to ensure the motion accuracy.

[0047] Specifically: fixed side plate 9 and device base 10 are fixedly connected, lifting mechanism 6 (such as precision lead screw sliding table or linear motor) is directly installed and fixed on the fixed side plate 9, copper-clad plate fixed platform 2 is connected with the sliding block of lifting mechanism 6, and the copper-clad plate fixed platform 2 can be moved stably up and down (Z-axis direction) along the fixed side plate by the driving of lifting mechanism controller 7.Under the control of lifting mechanism controller, the height of the copper-clad plate fixed platform is adjusted, so that the copper-clad plate is located in the focal plane of the direct imaging device.This design is not only used for adjusting the coating height, but more importantly, for accurately sending the copper-clad plate into the focal range of direct imaging device 1.

[0048] X-axis linear motion mechanism is installed on device base;X-axis linear motion mechanism 4 is directly fixed on device base 10, and X-axis linear motion mechanism 4 is connected with roller coating mechanism 3.Under the control of X-axis linear motion mechanism controller 5, roller coating mechanism 3 can be horizontally scanned relative to copper-clad plate fixed platform 2, so that the coating roller rolls on the surface of copper-clad plate, and the uniform coating of photosensitive material is completed.Usually, the coating of photosensitive material is completed by one-way rolling of coating roller, and in order to ensure uniformity, the coating roller is rolled back and forth twice in the application.

[0049] Imaging and control system: the direct imaging device 1 (such as DLP light machine) is suspended and fixed on the top of the rack, above the copper-clad plate fixed platform 2, the direct imaging device adopts digital light processing DLP technology, and the wavelength range of its light source is 250-420 nm. The host PC 8 is the center of the whole machine, and is electrically connected with the X-axis linear motion mechanism controller 5, the lifting mechanism controller 7 and the direct imaging device 1, and has the working program of the whole machine (and the control panel, which can be programmed) for controlling the cooperative work of each part. The host PC is configured to directly control the exposure operation after the coating operation is completed, without baking in between.

[0050] As shown in Figure 9 , 10 The working process is as follows: the user places the copper-clad plate on the fixed platform 2. The host PC 8 with preset program and digital circuit pattern first instructs the lifting mechanism 6 to lift the fixed platform 2 to the coating height along the fixed side plate 9. The host PC 8 instructs the X-axis linear motion mechanism controller 5 to drive the X-axis linear motion mechanism 4 to drive the roller coating mechanism 3 to scan the surface of the copper-clad plate for reciprocating coating. The roller coating mechanism reciprocates at a constant speed under the drive of the X-axis linear motion mechanism, so that the photosensitive material forms a uniform film on the surface of the copper-clad plate. After coating is completed, the host PC 8 instructs the lifting mechanism 6 to lift the fixed platform 2 to the exposure height along the fixed side plate. Then, the PC transmits the digital circuit pattern data to the direct imaging device 1 to directly expose the copper-clad plate in the wet film state. The whole process does not need to move the plate to the external oven, realizing the integration and seamless connection of "coating-exposure".

[0051] The manufacturing process of double-sided copper-clad plate is as follows: the user places the copper-clad plate on the fixed platform 2. The host PC 8 with preset program and digital circuit pattern first instructs the lifting mechanism 6 to lift the fixed platform 2 to the coating height along the fixed side plate 9. The host PC 8 instructs the X-axis linear motion mechanism controller 5 to drive the X-axis linear motion mechanism 4 to drive the roller coating mechanism 3 to scan the surface of the copper-clad plate for reciprocating coating. After the front surface is coated, the copper-clad plate is turned over to coat the back surface (or back surface), and after the coating is completed, the host PC 8 instructs the lifting mechanism 6 to lift the fixed platform 2 to the exposure height along the fixed side plate. Then, the PC transmits the digital circuit pattern data to the direct imaging device 1 to directly expose the copper-clad plate in the wet film state; then turn over to expose the front surface; or use two sets of direct imaging devices for simultaneous exposure.

[0052] It should be noted that the resin types, equipment parameters, chemical reagent concentrations and the like described in the embodiments of the present application are merely illustrative and not limiting. A person skilled in the art can adjust them according to actual production needs and substrate material properties, and such adjustments do not deviate from the technical ideas and protection scope disclosed by the present application. For example, the substrate of the copper-clad plate can be epoxy glass cloth (FR-4), or ceramic, metal-based, or flexible materials such as polyimide. The light source of the direct imaging device can be a laser or an LED array. These changes all belong to equivalent replacements or obvious modifications of the present application.

[0053] The above embodiments are only used to illustrate the technical solutions of the present application, but not to limit it; although the present application has been described in detail with reference to the foregoing embodiments, a person skilled in the art should understand that the technical solutions recorded in the foregoing embodiments can still be modified, or some or all of the technical features can be replaced by equivalents; and such modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for manufacturing a printed circuit board without baking, characterized in that, Includes the following steps: a1) Provide copper-clad laminates and perform brushing and cleaning pretreatment on the copper-clad laminates; b1) Drill holes in the copper-clad laminate, including insertion holes and positioning holes; c1) A photosensitive material is coated on the copper foil surface of the copper-clad laminate to form a photosensitive resin layer; d1) Using a direct imaging device, selective exposure is performed on the photosensitive resin layer according to preset digital circuit pattern data to form a cured circuit pattern on the resin layer. e1) Clean and remove the photosensitive resin from the unexposed areas to expose the copper foil underneath; f1) Etch the exposed copper foil; g1) Remove the solidified circuit pattern to obtain the final printed circuit board.

2. A method for manufacturing a double-sided printed circuit board without baking, characterized in that, It also includes the following steps: a2) Provide double-sided copper-clad laminates and perform brushing and cleaning pretreatment on the double-sided copper-clad laminates; b2) Drilling is performed on the double-sided copper-clad laminate, including metallized holes and non-metallized positioning holes; c2) The walls of the metallized holes are subjected to copper plating treatment; d2) A layer of photosensitive resin is coated on both sides of the double-sided copper-clad laminate to form a photosensitive resin layer; e2) Using a direct imaging device, selective exposure is performed on the front photosensitive resin layer according to the first preset digital circuit pattern data to form a cured circuit pattern on the resin layer. f2) Flipping process: Flip the double-sided copper-clad board, align it based on the non-metallized positioning holes in the drilled holes, and selectively expose the photosensitive resin layer on the reverse side according to the second preset digital circuit pattern data to form a cured circuit pattern on the resin layer. g2) Clean and remove the photosensitive resin from the unexposed areas to expose the copper foil underneath; h2) Etch the exposed copper foil; i2) Remove the solidified circuit pattern to obtain the final double-sided printed circuit board.

3. The printed circuit board manufacturing method according to claim 1 or 2, characterized in that, The removal of the cured circuit pattern refers to immersing the exposed copper-clad laminate in water or spraying it with organic solvent or pure water at room temperature, depending on the characteristics of the selected photosensitive resin.

4. The printed circuit board manufacturing method according to claim 1 or 2, characterized in that, The thickness of the photosensitive resin layer is in the range of 5 to 40 micrometers.

5. The printed circuit board manufacturing method according to claim 1 or 2, characterized in that, The direct imaging device is a digital light processing projection device or a laser scanning device that uses lasers or LEDs with wavelengths in the range of 250~420nm as light sources to project selective ultraviolet grayscale images.

6. The method for manufacturing a printed circuit board according to claim 1 or 2, characterized in that, The photosensitive resin is composed of resin monomers, prepolymers, diluents, and photoinitiators, and can undergo a polymerization reaction under ultraviolet light irradiation with a wavelength of 250~420nm to form an insoluble coating film.

7. The printed circuit board manufacturing method according to claim 2, characterized in that, The flipping process described in step f2) can also be replaced by adding a direct imaging device under the double-sided copper-clad board for exposure.

8. A baking-free printed circuit board manufacturing apparatus for implementing the method of claim 1, characterized in that, include: The device comprises a direct imaging device (1), a copper-clad laminate fixing platform (2), a roller coating mechanism (3), an X-axis linear motion mechanism (4), an X-axis linear motion mechanism controller (5), a lifting mechanism (6), a lifting mechanism controller (7), a host PC (8), a fixed side plate (9), and a device base (10). The fixed side plate is fixedly connected to the device base, and the lifting mechanism is mounted on the fixed side plate. The X-axis linear motion mechanism is mounted on the device base and its movement is controlled by the X-axis linear motion mechanism controller. The copper-clad laminate fixing platform is used to fix the copper-clad laminate and is connected to the lifting mechanism. Driven by the X-axis linear motion mechanism, the roller coating mechanism moves up and down along the fixed side plate. Driven by the X-axis linear motion mechanism, the roller coating mechanism reciprocates along the upper surface of the copper-clad laminate fixing platform, thereby performing rolling coating on the copper-clad laminate surface. The direct imaging device is suspended and fixed above the copper-clad laminate fixing platform for exposing the coated copper-clad laminate. The host PC is electrically connected to the X-axis linear motion mechanism controller, the lifting mechanism controller, and the direct imaging device to control the coordinated operation of each component.

9. The baking-free printed circuit board manufacturing apparatus according to claim 8, characterized in that, The device is an integrated desktop equipment. The fixed side plate, device base, lifting mechanism, copper-clad laminate fixing platform, roller coating mechanism and direct imaging equipment are integrated inside the same housing. The host PC is configured to directly control the exposure operation after the coating operation is completed, without performing a baking procedure in between.

10. The method of using the baking-free printed circuit board manufacturing apparatus according to claim 8, characterized in that, Its working steps are as follows: 1) Use the host PC to connect the direct imaging device, the X-axis linear motion mechanism controller and the lifting mechanism controller to fix the copper-clad laminate to be processed on the copper-clad laminate fixing platform; 2) The lifting mechanism drives the copper-clad laminate fixing platform to rise to the set coating height for the operation of the roller coating mechanism; 3) The X-axis linear motion mechanism is controlled by the X-axis linear motion mechanism controller to drive the roller coating mechanism to reciprocate. The roller coating mechanism rolls on the surface of the copper-clad laminate to form a uniform photosensitive material film. 4) The lifting mechanism drives the copper-clad laminate fixing platform to rise to the exposure height set by the imaging distance of the direct imaging device; 5) The direct imaging device selectively exposes the photosensitive material film on the surface of the copper-clad laminate to form a solidified circuit pattern; 6) The lifting mechanism drives the copper-clad laminate fixing platform to descend to the initial position.

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