Method for increasing etching factor in PCB etching process
By adding a mechanical processing process to remove part of the copper thickness in the PCB etching process, the problem of decreasing the etching factor of the thick copper plate is solved, the etching factor is improved and the side etching phenomenon is reduced, and the shape accuracy and impedance stability of the line conductor are improved.
Patent Information
- Application Number
- CN202510095804.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-22
- Publication Date
- 2025-06-10
AI Technical Summary
During the processing of multi-layer PCB boards, especially when the thickness of copper that needs to be etched increases, the etching factor often drops significantly, resulting in an intensification of side etching phenomenon, and it is difficult for traditional methods to improve the etching factor to a level comparable to that of thin copper boards.
After image transfer and development, a machining process is added, by drilling auxiliary positioning holes and optical alignment target holes to accurately locate, the part of the copper thickness that needs to be etched is removed by mechanical processing to reduce the etching amount and increase the etching factor.
By increasing the machining process, the etching amount is effectively reduced, the side etching phenomenon is reduced, the stability and reliability of the etching factor are improved, and the etching factor of the thick copper plate reaches a level comparable to that of the thin copper plate.
Smart Images
Figure CN120129152A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of PCB board processing, and specifically to a method for improving the etching factor in a PCB etching process. Background Art
[0002] In the processing of multi-layer PCB boards, the graphic production of the inner layer board is one of the key steps. This process usually includes operations such as laminating dry film or wet film, exposure, image transfer and development, etching, and film stripping. Among them, the etching process is particularly crucial because it directly relates to the shape and accuracy of the circuit conductors. The etching factor is an important indicator to measure the etching ability, which is defined as the ratio of the etching depth (the height of the trapezoid) to the undercut width (half of the difference between the lower side length and the upper side length of the trapezoid). The larger the etching factor, the closer the trapezoid approaches a rectangle, the smaller the undercut, the better the etching effect, and thus the more stable the line impedance obtained.
[0003] However, in actual production, especially when the copper thickness to be etched increases (such as 3oz, 4oz, 5oz thick copper plates, etc.), the etching factor often drops significantly. This is because the increase in the etching amount leads to the aggravation of the undercut phenomenon. Traditionally, the method for improving the etching factor mainly achieves it by adjusting etching parameters (such as pressure, speed, temperature, etc.). This method has good effects for thin copper plates (such as 1 / 2oz, 1oz, 2oz, etc.), but when the copper thickness increases to a certain extent, no matter how the parameters are adjusted, it is difficult to increase the etching factor to the same level as that of thin copper plates. Summary of the Invention
[0004] The purpose of the present invention is to propose a method for improving the etching factor in a PCB etching process by optimizing the traditional etching process, especially by adding a mechanical processing step after image transfer and development and before etching to reduce the copper thickness to be etched, thereby reducing the etching amount and increasing the etching factor, so that the etching factor of thick copper plates reaches the same level as that of thin copper plates.
[0005] The technical solution of the present invention to solve the above technical problems is as follows:
[0006] A method for improving the etching factor in a PCB etching process, comprising the following steps:
[0007] S10. Drilling auxiliary positioning holes and optical alignment target holes: Drilling auxiliary positioning holes and optical alignment target holes on the inner layer copper-clad substrate of the PCB for positioning and alignment in subsequent processes;
[0008] S20. Laminating the inner layer board with film: Performing an operation of laminating dry film or wet film on the inner layer double-sided board;
[0009] S30. Inner layer board exposure: The inner layer board covered with photosensitive material is exposed by an exposure device to cure the photosensitive material on the surface of the circuit or pattern to be retained.
[0010] S40. Inner layer board development: The uncured photosensitive material on the surface of the inner layer board is removed using a developer to expose the copper part to be etched.
[0011] S50. Inner layer board machining: Before etching after development, a machining process is added. The board is fixed on the table using positioning holes, and the optical alignment target holes are accurately located by a CCD probe. Part of the copper thickness at the position to be etched is removed by machining to reduce the etching amount and reduce the undercut phenomenon.
[0012] S60. Inner layer board etching: The inner layer board after machining is etched.
[0013] S70. Inner layer board desmearing: The photosensitive material is removed by a desmearing solution to obtain a circuit board with the etched pattern.
[0014] Based on the above technical solutions, the present invention can be further improved as follows.
[0015] Furthermore, in step S10, when drilling the auxiliary positioning holes and optical alignment target holes, a 100% expansion and contraction design is adopted. Two groups of holes are drilled on the PCB inner layer copper-clad substrate. The first group of holes has a diameter of 3.15 mm and a quantity of 3, which are used to fix the board surface during the subsequent mechanical copper removal process. The second group of holes has a diameter of 2.0 mm and a quantity of 4, which are located at the four corners of the inner layer board and are used for grasping and positioning during exposure and for the CCD probe to grasp the optical alignment target holes for positioning during the mechanical copper removal process.
[0016] Furthermore, in step S20, the photosensitive material pressed is a dry film or a wet film, and the dry film or wet film has photosensitive properties and adhesiveness to ensure that the photosensitive material on the surface of the circuit or pattern to be retained can be accurately cured during the exposure process.
[0017] Furthermore, in step S30, the exposure device is one of a UV exposure machine or an LDI exposure machine, and the exposure device is provided with a grasping hole positioning module to accurately grasp the optical alignment target holes for positioning during the exposure process, thereby achieving precise exposure.
[0018] Furthermore, in step S50, the machining method adopts a machining method such as laser laser, mechanical drilling, mechanical deep drilling, or mechanical blind fishing, and the machining equipment is provided with a hole grasping positioning component to accurately grasp the optical alignment target holes for positioning during the machining process, thereby achieving precise copper reduction.
[0019] Further, in step S50, when designing the copper reduction window in the mechanical program, it is 1 mil smaller than the window to be etched on each side to ensure that the circuits or patterns to be retained are not damaged during the machining process.
[0020] Further, in step S60, the etching operation is carried out using an etching solution.
[0021] Further, the method further includes a step of inspecting the circuit board after etching to ensure the etching quality and accuracy. The inspection methods include but are not limited to visual inspection, microscopic inspection, or electrical performance testing.
[0022] Further, in step S70, the desmearing operation is carried out using a desmearing solution. After the desmearing operation, cleaning and drying treatments are also required to thoroughly remove the residual desmearing solution and moisture, ensuring the cleanliness and dryness of the circuit board.
[0023] Compared with the prior art, the technical solution of the present application has the following beneficial technical effects:
[0024] Before etching, a mechanical processing procedure is added. The board is fixed on the table using positioning holes, and the optical alignment target holes are captured by a CCD probe for precise positioning. Then, a mechanical processing method is used to remove part of the copper thickness at the position to be etched. Secondly, the steps of the method are closely connected, forming a complete process flow. Starting from drilling the auxiliary positioning holes and optical alignment target holes, to inner layer board laminating, exposure, development, then to mechanical processing, etching, and desmearing, each step provides a basis for the smooth progress of the next step. In particular, the addition of the mechanical processing procedure not only reduces the etching amount but also provides more precise positioning and alignment for the subsequent etching operation, thereby improving the accuracy and stability of the entire process flow. In addition, the method fully considers the positioning and alignment problems in the PCB board processing process. Through the drilled auxiliary positioning holes and optical alignment target holes, and using the CCD probe for precise positioning, the accuracy of the mechanical processing and etching operations is ensured. This high-precision positioning and alignment method helps to reduce errors and deviations during the processing, further improving the stability and reliability of the etching factor. In summary, by adding a mechanical processing procedure, optimizing the process flow, and improving the positioning and alignment accuracy, etc., the method effectively improves the etching factor in the PCB etching process, reduces the occurrence of side etching, and thus improves the shape accuracy and impedance stability of the circuit conductors. Description of the Drawings
[0025] Figure 1 It is a method flow chart of a method for improving the etching factor in a PCB etching process of the present invention. Detailed Embodiments
[0026] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.
[0027] Combined with Figure 1 As shown, a method for improving the etching factor in a PCB etching process of the present invention includes the following steps:
[0028] S10. Drilling auxiliary positioning holes and optical alignment target holes: Drill auxiliary positioning holes and optical alignment target holes on the inner-layer copper-clad substrate of the PCB for positioning and alignment in subsequent processes;
[0029] S20. Laminating dry film or wet film on the inner layer board: Perform an operation of laminating dry film or wet film on the inner-layer double-sided board;
[0030] S30. Exposing the inner layer board: Perform an exposure action on the inner layer board covered with photosensitive material through an exposure device to cure the photosensitive material on the surface of the circuit or pattern to be retained;
[0031] S40. Developing the inner layer board: Use a developer to remove the uncured photosensitive material on the surface of the inner layer board, exposing the copper part to be etched;
[0032] S50. Machining the inner layer board: Add a machining process after developing and before etching. Fix the board on the table using the positioning holes, accurately position by grabbing the optical alignment target holes through a CCD probe, and use a machining method to remove a part of the copper thickness at the position to be etched to reduce the etching amount and reduce the side etching phenomenon;
[0033] S60. Etching the inner layer board: Perform an etching operation on the inner layer board after machining treatment;
[0034] S70. Removing the glue on the inner layer board: Remove the photosensitive material through a degumming solution to obtain a circuit board with the etched pattern.
[0035] In a preferred embodiment, the present invention can be further configured as follows: in step S10, when drilling the auxiliary positioning holes and the optical alignment target holes, a 100% expansion and contraction design is adopted. Two sets of holes are drilled on the inner-layer copper-clad substrate of the PCB. The first set of holes has a diameter of 3.15 mm and a quantity of 3, which are used to fix the board surface during the subsequent mechanical copper removal process. The second set of holes has a diameter of 2.0 mm and a quantity of 4, which are located at the four corners of the inner layer board and are used for grasping and positioning during exposure and for grasping the optical alignment target holes through a CCD probe for positioning during the mechanical copper removal process. In step S10, a 100% expansion and contraction design is adopted to drill the auxiliary positioning holes and the optical alignment target holes. This design not only takes into account the thermal expansion and contraction problems of the PCB board during the processing, but also fully considers the accuracy of positioning and alignment. By drilling two sets of holes, the first set of holes with a diameter of 3.15 mm and a quantity of 3 are mainly used to fix the board surface during the subsequent mechanical copper removal process. This design ensures that during mechanical processing, the PCB board can be stably fixed on the workbench, avoiding processing errors caused by board surface shaking or movement. At the same time, the design of 3 holes also provides sufficient stability, enabling the board surface to remain flat during the copper thickness removal process, further improving the processing accuracy. The second set of holes with a diameter of 2.0 mm and a quantity of 4 are located at the four corners of the inner layer board. These holes are not only used for grasping and positioning during exposure, but also for grasping the optical alignment target holes through a CCD probe for positioning during the mechanical copper removal process. This design enables high-precision positioning and alignment to be achieved during both exposure and mechanical processing. Especially during mechanical processing, positioning by grasping the optical alignment target holes through a CCD probe can greatly improve the processing accuracy and stability, thereby reducing the occurrence of side etching and improving the stability of the etching factor. In addition, the balance between the overall stability and local accuracy of the PCB board during the processing is also considered. By reasonably designing the positions and quantities of the two sets of holes, both the overall stability of the board surface and local high-precision positioning and alignment are ensured. This design not only improves the processing accuracy and efficiency, but also helps to reduce production costs and improve product quality.
[0036] In a preferred embodiment, the present invention can be further configured as follows: in step S20, the photosensitive material to be pressed is a dry film or a wet film, and the dry film or the wet film has photosensitive properties and adhesiveness to ensure that the photosensitive material on the surface of the circuit or pattern to be retained can be accurately cured during the exposure process. First, the selection of the dry film or the wet film provides flexibility. The dry film has excellent resolution and adhesiveness, is suitable for the manufacture of fine circuits, and is easy to operate, store, and transport. The wet film has better filling and covering properties, is suitable for the production of complex patterns, and can meet the requirements of different thicknesses by adjusting the coating parameters. Therefore, according to the specific PCB design requirements and processing conditions, the most suitable photosensitive material can be selected to improve production efficiency and product quality. Second, the excellent photosensitive properties and adhesiveness contribute to improving the processing accuracy and stability. During the exposure process, the photosensitive material can accurately cure the surface of the circuit or pattern to be retained, avoiding processing errors caused by insufficient or excessive curing. At the same time, the tight adhesiveness ensures the stability of the photosensitive material in the subsequent development and etching steps, avoiding circuit deformation or damage caused by material shedding or displacement.
[0037] In a preferred embodiment, the present invention can be further configured as follows: in step S30, the exposure device is one of a UV exposure machine or an LDI exposure machine, and a grab hole positioning module is provided in the exposure device to accurately grab the optical alignment target holes for positioning during the exposure process, so as to achieve precise exposure. In step S30, it is pointed out that the exposure device is one of a UV exposure machine or an LDI exposure machine. These two exposure devices are widely used in the field of PCB manufacturing. The UV exposure machine exposes the photosensitive material through a UV light source and is suitable for large-area and high-efficiency exposure requirements; while the LDI exposure machine uses direct laser imaging technology and has the advantages of high precision and high resolution, and is suitable for the manufacture of fine circuits. According to the specific PCB design requirements and processing conditions, the most suitable exposure device can be selected to meet the requirements of processing accuracy and efficiency. It is also emphasized that a grab hole positioning module is provided in the exposure device. The introduction of this functional module enables the exposure device to accurately grab the optical alignment target holes for positioning during the exposure process, so as to achieve precise exposure. The optical alignment target holes are pre-drilled on the inner-layer copper-clad substrate of the PCB for positioning and alignment in subsequent processes. Through the grab hole positioning module, the exposure device can automatically identify and position these target holes to ensure the accuracy of the exposure position.
[0038] In a preferred embodiment, the present invention can be further configured as follows: in step S50, the machining method adopts one of laser laser, mechanical drilling, mechanical deep drilling or mechanical blind fishing, and a hole-grabbing positioning component is provided in the machining equipment to accurately grab the optical alignment target hole for positioning during the machining process, so as to achieve precise copper reduction. In step S50, it is clearly pointed out that the machining method can adopt one of machining methods such as laser laser, mechanical drilling, mechanical deep drilling or mechanical blind fishing. These machining methods have their own advantages. For example, laser laser has the characteristics of high precision, high speed and non-contact machining, and is suitable for copper reduction treatment of fine circuits; mechanical drilling is suitable for machining of larger hole diameters and thicker copper plates; mechanical deep drilling can handle deep holes and blind holes to meet the requirements of specific PCB designs; mechanical blind fishing can accurately remove the copper layer at the specified position without damaging other circuits. According to the specific PCB design requirements and processing conditions, the most suitable machining method can be selected to meet the requirements of machining accuracy and efficiency. A hole-grabbing positioning component is provided in the machining equipment. The introduction of this functional component enables the machining equipment to accurately grab the optical alignment target hole for positioning during the machining process, so as to achieve precise copper reduction. The optical alignment target hole is pre-drilled on the inner-layer copper-clad substrate of the PCB for positioning and alignment in subsequent processes. Through the hole-grabbing positioning component, the machining equipment can automatically identify and position these target holes to ensure the accuracy of the copper reduction position.
[0039] In a preferred embodiment of the present invention, it can be further configured as follows: In step S50, when the mechanical program designs the copper reduction window, it is 1 mil smaller than the window to be etched on each side, so as to ensure that the circuits or patterns to be retained will not be damaged during the machining process. In step S50, when the mechanical program designs the copper reduction window, it is 1 mil (i.e., 0.0254 mm) smaller than the window to be etched on each side. This design cleverly balances the copper reduction effect and the safety margin for protecting the circuits or patterns to be retained. By precisely controlling the size of the copper reduction window, it ensures the accuracy of copper reduction during the machining process, while avoiding damaging the circuits or patterns to be retained due to excessive copper reduction. It effectively reduces the risk of damage to the circuits or patterns to be retained during the machining process. In traditional machining methods, due to improper design of the copper reduction window or insufficient machining accuracy, it is often easy to damage the circuits or patterns to be retained during the copper reduction process, resulting in a decline in product quality. However, the technical features in this claim ensure the safety during the machining process by precisely controlling the size of the copper reduction window, avoiding the occurrence of such problems, and also helping to improve the overall efficiency of PCB manufacturing. By removing part of the copper thickness in advance during the machining process, the etching amount in the subsequent etching step can be reduced, thereby shortening the etching time and improving the production efficiency. At the same time, due to the more precise design of the copper reduction window, the rework and scrap situations caused by machining errors are also reduced, further improving the production efficiency and product quality.
[0040] In a preferred embodiment of the present invention, it can be further configured as follows: In step S60, the etching operation is carried out using an etching solution, which contains one or more chemical reagents that can chemically react with copper to remove it from the PCB surface. By precisely controlling parameters such as the composition, concentration, temperature, and etching time of the etching solution, precise control of the etching process can be achieved, ensuring the uniformity and accuracy of etching. During the PCB manufacturing process, the copper layers to be removed are often distributed in different areas with different thicknesses and shapes. Traditional etching methods may lead to uneven etching due to the inability to precisely control the etching conditions, thereby affecting the quality and performance of the PCB. However, using an etching solution for etching can achieve precise etching of copper layers in different areas by adjusting parameters such as the composition and concentration of the etching solution, ensuring a flat and uniform surface of the etched PCB. Secondly, the etching solution etching method helps to reduce the occurrence of undercutting. Undercutting is one of the common problems in the etching process, which can cause the line width to become narrower and the shape to be distorted, thereby affecting the electrical performance and reliability of the PCB. When using an etching solution for etching, the occurrence of undercutting can be reduced by optimizing the formula of the etching solution and the etching conditions, such as reducing the acidity of the etching solution and increasing the etching temperature, so as to protect the integrity and accuracy of the circuits or patterns to be retained.
[0041] In a preferred embodiment of the present invention, it can be further configured that: the method further includes a step of inspecting the circuit board after etching to ensure the etching quality and accuracy. The inspection methods include, but are not limited to, visual inspection, microscopic inspection, or electrical performance testing. The importance of inspecting the circuit board after etching is that it helps to promptly detect and correct various defects that may occur during the etching process, such as inconsistent line widths, line breaks, copper layer residues, etc., thereby ensuring the smooth progress of subsequent processing steps and the quality and accuracy of the final product. Through inspection, potential quality problems can be promptly discovered and prevented from expanding or causing more serious consequences in subsequent processing. Multiple inspection methods are also provided, including visual inspection, microscopic inspection, and electrical performance testing, etc. These inspection methods have their own advantages and can complement each other to ensure the comprehensiveness and accuracy of the inspection. Visual inspection can quickly detect obvious defects, such as line breaks or copper layer residues; microscopic inspection can further observe the microscopic structure of the lines and detect more subtle defects; electrical performance testing can verify the conductivity and electrical connectivity of the lines to ensure that the electrical performance of the circuit board meets the design requirements.
[0042] In a preferred embodiment of the present invention, it can be further configured that: in step S70, the degumming operation is carried out using a degumming solution, and after the degumming operation, cleaning and drying treatments are also required to thoroughly remove the residual degumming solution and moisture, ensuring the cleanliness and dryness of the circuit board. The introduction of the cleaning and drying treatment steps further ensures the cleanliness and dryness of the circuit board. During the degumming process, the degumming solution may remain in the tiny gaps or holes of the circuit board. If not thoroughly cleaned, these residues may cause problems during subsequent processing or use of the circuit board, such as affecting the welding quality or resulting in poor electrical connections. Therefore, through the cleaning step, the residual degumming solution can be thoroughly rinsed off using a cleaning agent such as a solvent or water to ensure that both the surface and the interior of the circuit board meet the cleanliness standard. At the same time, the drying treatment step is also essential. After cleaning, moisture may remain on the surface and inside the circuit board. If not dried, the moisture may cause problems such as corrosion and oxidation during subsequent processing or storage, seriously affecting the performance and reliability of the circuit board. Therefore, through the drying treatment, the moisture on the circuit board can be thoroughly removed using equipment such as hot air, vacuum drying, or an oven to ensure the dryness of the circuit board.
[0043] The specific working principle of the method for improving the etching factor in a PCB etching process of the present invention is as follows:
[0044] This PCB etching process aims to improve the etching factor and ensure the etching quality and precision of the circuit board through a series of precise steps. The entire process starts from the inner-layer copper-clad substrate of the PCB. First, auxiliary positioning holes and optical alignment target holes are drilled. These holes adopt a 100% expansion and contraction design and are divided into two groups. One group is used for fixation during the subsequent mechanical copper removal process, and the other group is used for precise positioning during the exposure and mechanical copper removal processes. Next, a film laminating operation is performed on the inner-layer board, using a dry film or wet film with photosensitive and adhesive properties to ensure that the photosensitive material on the surface of the circuit or pattern to be retained can be accurately cured during the exposure process. The exposure step uses a UV exposure machine or an LDI exposure machine. The device is equipped with a grabbing hole positioning module that can accurately grab the optical alignment target holes for positioning to achieve precise exposure. After exposure, a developing operation is carried out, using a developer to remove the uncured photosensitive material and expose the copper part to be etched. At this time, a key machining process is entered. After developing and before etching, the board is fixed on the table using the positioning holes, and the optical alignment target holes are grabbed by a CCD probe for precise positioning. Then, mechanical machining methods such as laser ablation, mechanical drilling, mechanical deep drilling, or mechanical blind fishing are used to remove part of the copper thickness at the position to be etched, so as to reduce the etching amount and reduce the side etching phenomenon. During this process, the copper reduction window designed by the mechanical program is 1 mil smaller than the single side of the window to be etched, ensuring that the circuits or patterns to be retained will not be damaged. Subsequently, the etching operation is carried out, using an etching solution to remove the remaining copper layer to obtain the required circuit pattern. After etching, the circuit board is inspected. The inspection methods include visual inspection, microscopic inspection, or electrical performance testing to ensure the etching quality and precision. Finally, a degumming operation is carried out, using a degumming solution to remove the photosensitive material, and then cleaning and drying treatments are carried out to thoroughly remove the residual degumming solution and moisture, ensuring the cleanliness and dryness of the circuit board.
[0045] It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "including", "comprising" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "including a..." does not exclude the existence of additional identical elements in the process, method, article or device including the said element.
[0046] Although embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.
Claims
1. A method for improving etching factor in a PCB etching process, characterized in that: The following steps are involved: S10, drilling auxiliary positioning holes and optical alignment target holes: drilling auxiliary positioning holes and optical alignment target holes on the inner copper-clad substrate of the PCB for positioning and alignment in subsequent processes; S20, inner layer board lamination: laminating the inner double-sided board with dry film or wet film; S30, inner layer board exposure: the inner layer board covered with the photosensitive material is exposed by an exposure device to solidify the photosensitive material on the circuit or pattern surface to be retained; S40, inner layer board development: using a developer to remove the uncured photosensitive material on the surface of the inner layer board to expose the copper part that needs to be etched; S50, inner layer board machining: add a machining process after development and before etching, use the positioning hole to fix the board on the table, use the CCD probe to grab the optical alignment target hole for precise positioning, and use mechanical processing to remove part of the copper thickness at the position to be etched to reduce the etching amount and reduce the side etching phenomenon; S60, inner layer board etching: etching the inner layer board after mechanical processing; S70, inner layer board degumming: remove the photosensitive material with degumming liquid to obtain a circuit board with etched patterns.
2. The method for improving etching factor in a PCB etching process according to claim 1, characterized in that: In step S10, when drilling auxiliary positioning holes and optical alignment target holes, a 100% expansion and contraction design is adopted, and two groups of holes are drilled on the inner copper-clad substrate of the PCB. The first group of holes has a diameter of 3.15 mm and a number of 3 holes, which are used to fix the board surface during the subsequent mechanical copper removal process; the second group of holes has a diameter of 2.0 mm and a number of 4 holes, which are located at the four corners of the inner board and are used for grasping and positioning during exposure and for grasping the optical alignment target holes for positioning through the CCD probe during the mechanical copper removal process.
3. The method for improving etching factor in a PCB etching process according to claim 1, characterized in that: In step S20, the laminated photosensitive material is a dry film or a wet film, and the dry film or the wet film has photosensitive properties and adhesion, so as to ensure that the photosensitive material on the circuit or pattern surface to be retained can be accurately cured during the exposure process.
4. The method for improving etching factor in a PCB etching process according to claim 1, characterized in that: In step S30, the exposure device is a UV exposure machine or an LDI exposure machine, and a gripping hole positioning module is provided in the exposure device to accurately grip the optical alignment target hole for positioning during the exposure process, thereby achieving precise exposure.
5. The method for improving etching factor in a PCB etching process according to claim 1, characterized in that: In step S50, the mechanical processing method adopts one of the machining methods of laser, mechanical drilling, mechanical deep drilling or mechanical blind fishing, and the mechanical processing equipment is provided with a hole grasping and positioning component to accurately grasp the optical alignment target hole for positioning during the mechanical processing process, thereby achieving precise copper reduction.
6. The method for improving etching factor in a PCB etching process according to claim 1, characterized in that: In step S50, when designing the copper reduction window, the mechanical program is 1 mil smaller than the single side of the window to be etched to ensure that the circuits or patterns to be retained will not be damaged during the mechanical processing.
7. The method for improving etching factor in a PCB etching process according to claim 1, characterized in that: In step S60, the etching operation is performed using an etching solution.
8. A method for improving etching factor in a PCB etching process according to any one of claims 1 to 7, characterized in that: The method also includes the step of inspecting the circuit board after etching to ensure etching quality and accuracy, and the inspection method includes but is not limited to visual inspection, microscopic inspection or electrical performance testing.
9. The method for improving etching factor in a PCB etching process according to claim 1, characterized in that: In step S70, the degumming operation is performed using a degumming liquid, and after the degumming operation, cleaning and drying treatments are required to completely remove the residual degumming liquid and moisture to ensure the cleanliness and dryness of the circuit board.