Process method for removing drilling burrs and circuit board

Abstract

The invention discloses a process method for removing drill hole burrs and a circuit board, and the process method for removing drill hole burrs comprises the steps: mechanical board grinding: carrying out the board grinding treatment of the circuit board after the circuit board is drilled; primary washing: carrying out washing treatment on the circuit board after mechanical board grinding; and chemical micro-etching: after primary water washing, carrying out micro-etching treatment on the circuit board by using chemical liquid medicine so as to etch burrs at the orifice of the circuit board. Through combination of mechanical plate grinding, primary water washing and chemical micro-etching, drilling burrs are thoroughly removed, the defect rate is remarkably reduced, the orifice structure is protected, the surface cleanliness is improved, the reliability of subsequent procedures and the production efficiency are enhanced, environmental pollution is reduced, and the overall product quality and the production flexibility are improved.

Description

Technical Field

[0001] The invention relates to the technical field of circuit board manufacturing, and in particular to a process method for removing drilling burrs, and a circuit board having the process method for removing drilling burrs. Background Art

[0002] In the modern electronic manufacturing industry, printed circuit boards are the basic components of electronic equipment, and their quality and performance directly affect the reliability and stability of the entire electronic system. The manufacturing process of circuit boards is complex and involves multiple key processes, one of which is drilling. Drilling is an essential step in circuit board manufacturing and is used to achieve electrical connections between different layers. However, burrs are inevitably generated during the drilling process, which not only affects the appearance quality of the circuit board, but also causes a series of problems in the subsequent manufacturing process.

[0003] At present, the main method of removing drilling burrs is mechanical grinding, including the use of tools such as abrasive belts, non-woven rollers and needle brush rollers. Although these methods can remove burrs to a certain extent, they also have some obvious disadvantages: 1. Grinding pressure is difficult to control: The greater the grinding pressure, the better the burr removal effect, but too much pressure can easily scratch the hole, causing the hole to deform or wear through. This not only affects the appearance quality of the circuit board, but may also damage the conductive layer in the hole and affect the electrical performance.

[0004] 2. Limited removal effect: Even under the best pressure conditions, it is impossible to completely remove all burrs, and there is still a certain defect rate, usually around 100PPM. These burrs that are not completely removed may cause quality problems in the subsequent manufacturing process.

[0005] 3. Quality issues: Burrs that are not completely removed may pierce the dry film during the subsequent pattern transfer process, causing open or short holes, affecting the quality of the final product. Even if only one circuit board has a problem, it may cause the entire batch of products to be scrapped, resulting in huge economic losses.

[0006] Although the existing mechanical grinding method is very mature, there are still some problems that cannot be ignored in practical applications: (1) Narrow window of pressure control: The grinding pressure needs to be adjusted to an appropriate range, but this range is very narrow. Any normal process fluctuations may result in incomplete burr removal. This makes it difficult to achieve the ideal removal effect in actual operation. (2) It is difficult to further reduce the defect rate: Even under the best operating conditions, the existing mechanical grinding method cannot reduce the burr defect rate to zero. This forces circuit board factories to spend a lot of energy and resources to deal with these defects, increasing production costs. Summary of the invention

[0007] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes a process for removing drilling burrs, which can completely remove drilling burrs by combining mechanical grinding, initial water washing and chemical micro-etching, significantly reduce the defect rate, protect the hole structure, improve surface cleanliness, enhance the reliability and production efficiency of subsequent processes, reduce environmental pollution, and improve overall product quality and production flexibility.

[0008] The present invention also provides a circuit board having the above-mentioned process method for removing drilling burrs.

[0009] A process for removing drilling burrs according to the present invention comprises: Mechanical grinding: After drilling holes in the circuit board, the circuit board is subjected to grinding treatment; Initial water washing: After mechanical grinding, the circuit board is washed with water; Chemical micro-etching: After the initial water washing, the circuit board is micro-etched using chemical solutions to etch away the burrs at the openings of the circuit board.

[0010] The process for removing drilling burrs according to the present invention has at least the following beneficial effects: 1. Double deburring mechanism: First, most of the visible burrs are removed by mechanical grinding, and then chemical micro-etching is used to treat the burrs at the fine part of the hole. This "rough first, fine later" treatment method ensures the comprehensiveness and thoroughness of burr removal and greatly reduces the possibility of burr residue.

[0011] 2. Protect the hole structure: Chemical micro-etching is a gentle and controllable treatment method that can accurately remove tiny burrs around the hole without causing excessive damage to the hole, maintaining the original shape and size of the hole, and ensuring that the electrical performance of the circuit board is not affected.

[0012] 3. Improve surface cleanliness: The initial water washing step effectively removes the dust and debris generated during the mechanical grinding process, providing a clean base for subsequent chemical micro-etching, ensuring that the chemical solution can act evenly on the hole mouth and improve the deburring effect.

[0013] 4. Enhance the reliability of subsequent processes: The surface of the processed circuit board is smoother and neater, which reduces the problems of dry film puncture, hole open circuit or hole short circuit that may occur in subsequent processes, and improves the quality and reliability of the final product.

[0014] According to a process for removing drilling burrs described in some embodiments of the present invention, in the chemical micro-etching, the chemical solution is a micro-etching solution.

[0015] According to a process method for removing drilling burrs described in some embodiments of the present invention, in the chemical micro-etching, the micro-etching amount of the micro-etching treatment is A, which satisfies: A≥1 micron.

[0016] According to a process for removing drilling burrs described in some embodiments of the present invention, in the chemical micro-etching, the micro-etching amount of the micro-etching treatment is A, which satisfies: A≤5 microns.

[0017] According to some embodiments of the present invention, a process for removing drilling burrs satisfies: 2 microns ≤ A ≤ 3 microns.

[0018] According to a process for removing drilling burrs described in some embodiments of the present invention, in the mechanical grinding plate, the grinding plate treatment includes at least one of a non-woven grinding plate, a needle brush grinding plate and an abrasive belt grinding plate.

[0019] According to a process for removing drilling burrs described in some embodiments of the present invention, in the initial water washing, the water washing treatment includes ordinary water washing and ultrasonic water washing.

[0020] According to some embodiments of the present invention, a process for removing drilling burrs further includes: water washing again: after chemical micro-etching, the circuit board is subjected to high-pressure water washing.

[0021] According to some embodiments of the present invention, a process for removing drilling burrs further includes: drying: drying the circuit board after washing again.

[0022] According to the circuit board of the present invention, a process method for removing drilling burrs of the present invention is applied.

[0023] The circuit board according to the present invention has at least the following beneficial effects: the above-mentioned process method for removing drilling burrs is adopted to ensure that the circuit board is effectively burred during the manufacturing process. This improvement significantly improves the quality and reliability of the circuit board, reduces the defect rate, reduces production costs, and improves overall production efficiency and market competitiveness.

[0024] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which: Figure 1 A process flow chart of a process method for removing drilling burrs according to an embodiment of the present invention; Figure 2The present invention is another process flow chart of a process method for removing drilling burrs according to another embodiment of the present invention.

[0026] Description of Figure Numbers: Non-woven grinding plate 110; needle brush grinding plate 120; sanding belt grinding plate 130; Ordinary water washing 210; Ultrasonic water washing 220; High pressure water washing 410. DETAILED DESCRIPTION

[0027] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0028] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., and orientations or positional relationships indicated are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0029] In the description of the present invention, "several" means one or more, "more" means more than two, "greater than", "less than", "exceed" etc. are understood as not including the number itself, and "above", "below", "within" etc. are understood as including the number itself. If there is a description of "first" or "second", it is only used for the purpose of distinguishing the technical features, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0030] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0031] In the description of the present invention, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0032] In the modern electronic manufacturing industry, printed circuit boards are the basic components of electronic equipment, and their quality and performance directly affect the reliability and stability of the entire electronic system. The manufacturing process of circuit boards is complex and involves multiple key processes, one of which is drilling. Drilling is an essential step in circuit board manufacturing and is used to achieve electrical connections between different layers. However, burrs are inevitably generated during the drilling process, which not only affects the appearance quality of the circuit board, but also causes a series of problems in the subsequent manufacturing process.

[0033] At present, the main method of removing drilling burrs is mechanical grinding, including the use of tools such as abrasive belts, non-woven rollers and needle brush rollers. Although these methods can remove burrs to a certain extent, they also have some obvious disadvantages: 1. Grinding pressure is difficult to control: The greater the grinding pressure, the better the burr removal effect, but too much pressure can easily scratch the hole, causing the hole to deform or wear through. This not only affects the appearance quality of the circuit board, but may also damage the conductive layer in the hole and affect the electrical performance.

[0034] 2. Limited removal effect: Even under the best pressure conditions, it is impossible to completely remove all burrs, and there is still a certain defect rate, usually around 100PPM. These burrs that are not completely removed may cause quality problems in the subsequent manufacturing process.

[0035] 3. Quality issues: Burrs that are not completely removed may pierce the dry film during the subsequent pattern transfer process, causing open or short holes, affecting the quality of the final product. Even if only one circuit board has a problem, it may cause the entire batch of products to be scrapped, resulting in huge economic losses.

[0036] Although the existing mechanical grinding method is very mature, there are still some problems that cannot be ignored in practical applications: (1) Narrow window of pressure control: The grinding pressure needs to be adjusted to an appropriate range, but this range is very narrow. Any normal process fluctuations may result in incomplete burr removal. This makes it difficult to achieve the ideal removal effect in actual operation. (2) It is difficult to further reduce the defect rate: Even under the best operating conditions, the existing mechanical grinding method cannot reduce the burr defect rate to zero. This forces circuit board factories to spend a lot of energy and resources to deal with these defects, increasing production costs.

[0037] For this reason, Figure 1 As shown, a process for removing drilling burrs proposed by the present invention includes the following steps performed in sequence: S100, mechanical grinding: After drilling the circuit board, the circuit board is ground; S200, initial water washing: after mechanical grinding, the circuit board is washed with water; S300, chemical micro-etching: After the initial water washing, use chemical solution to micro-etch the circuit board to etch the burrs at the openings of the circuit board.

[0038] It should be noted that the double deburring mechanism is used. Specifically, most of the visible burrs are first removed by mechanical grinding, and then the burrs at the fine part of the orifice are treated with chemical microetching. This "rough first and fine later" treatment method ensures the comprehensiveness and thoroughness of burr removal and greatly reduces the possibility of burr residue. In addition, chemical microetching, as a gentle and controllable treatment method, can accurately remove the tiny burrs around the orifice without causing excessive damage to the orifice, maintain the original shape and size of the orifice, effectively protect the orifice structure, and ensure that the electrical performance of the circuit board is not affected. In addition, the initial water washing step effectively removes the dust and debris generated during the mechanical grinding process, provides a clean base for the subsequent chemical microetching, ensures that the chemical solution can act evenly on the orifice, and improves the deburring effect. Furthermore, the surface of the circuit board after treatment is smoother and neater, reducing the problems of dry film puncture, hole open circuit or hole short circuit that may occur in subsequent processes, and improving the quality and reliability of the final product.

[0039] Further, refer to Figure 1 , further comprising the following steps: S400, water washing again: After chemical micro-etching, the circuit board is subjected to high-pressure water washing 410. In this regard, high-pressure water washing 410 can effectively remove the chemical liquid and tiny particles remaining in the chemical micro-etching process, ensuring that the surface of the circuit board is thoroughly cleaned. Also includes S500, drying: After washing again, the circuit board is dried. In this regard, the drying step can completely remove moisture from the surface of the circuit board to prevent corrosion, oxidation or other quality problems caused by residual moisture. A dry surface helps to maintain the electrical properties and mechanical strength of the circuit board and extend its service life. In addition, the dry surface of the circuit board provides good conditions for subsequent processing steps (such as plating, welding, coating, etc.), reduces process problems caused by residual moisture, such as poor solder joints and uneven coating, and improves the success rate and efficiency of subsequent processes. In some applications, dry circuit boards are not easily affected by moisture during storage and transportation, reducing the risks of short circuits and corrosion caused by moisture, and improving the storage and transportation safety of products.

[0040] In some embodiments of the present invention, in chemical micro-etching, the chemical solution is a micro-etching solution. It is easy to understand that the micro-etching solution has a specific chemical composition and concentration, which can effectively remove fine burrs at the orifice without damaging the substrate of the circuit board. This not only improves the accuracy and effect of deburring, but also significantly reduces the burr residual rate, further improving the surface quality and electrical performance of the circuit board. In addition, the selection and use of micro-etching solution can also reduce pollution to the environment, meeting the requirements of modern green manufacturing. Optionally, the micro-etching solution mainly includes: hydrogen peroxide + sulfuric acid system; sodium persulfate + sulfuric acid system, and ammonium persulfate + sulfuric acid system. Among them, the most widely used micro-etching solution is the hydrogen peroxide + sulfuric acid system.

[0041] In some applications, in chemical micro-etching, the micro-etching amount of the micro-etching treatment is A, which satisfies: A ≥ 1 micron, ensuring that the chemical micro-etching process can effectively remove the fine burrs at the orifice. This minimum value ensures the adequacy of the micro-etching process, prevents the residual burrs caused by insufficient micro-etching, and improves the thoroughness of deburring and the reliability of the product. In some applications, it satisfies: A ≤ 5 microns, ensuring that the chemical micro-etching process will not cause excessive damage to the orifice structure. This upper limit value prevents the deformation or wear of the orifice caused by excessive micro-etching, thereby protecting the original shape and size of the orifice and maintaining the electrical properties and mechanical strength of the circuit board. In some embodiments of the present invention, it satisfies: 2 microns ≤ A ≤ 3 microns. It should be noted that within the range of 2 microns to 3 microns, chemical micro-etching can achieve the best deburring effect. The micro-etching amount within this range can not only effectively remove the fine burrs at the orifice, but also avoid the damage to the orifice caused by excessive micro-etching, ensuring the thoroughness and accuracy of deburring. Specifically, the micro-etching amount of 2 to 3 microns is a mild and controllable range, which can effectively protect the structural integrity of the orifice, prevent the orifice from deformation or wear, and thus maintain the electrical performance and mechanical strength of the circuit board. In addition, the micro-etching amount within this range can ensure the smoothness and neatness of the orifice surface, reduce surface roughness, and improve the appearance quality of the circuit board, making it more in line with high-standard manufacturing requirements. By precisely controlling the amount of micro-etching, the defect rate caused by burr residue or orifice damage can be significantly reduced, the product qualification rate and reliability can be improved, scrap and rework can be reduced, and production costs can be reduced.

[0042] Optionally, refer to Figure 1 and Figure 2In the mechanical grinding, the grinding process includes at least one of the non-woven grinding plate 110, the needle brush grinding plate 120 and the sand belt grinding plate 130. The most suitable grinding method can be selected according to the specific material and thickness of the circuit board. For example, the non-woven grinding plate 110 is suitable for fine grinding, the needle brush grinding plate 120 is suitable for removing fine burrs, and the sand belt grinding plate 130 is suitable for quickly removing larger burrs. For another example, the non-woven grinding plate 110 is suitable for softer substrates, the needle brush grinding plate 120 is suitable for hard substrates, and the sand belt grinding plate 130 is suitable for thick substrates, ensuring the flexibility and applicability of the grinding process. In some applications, refer to Figure 1 For conventional copper plates below 1OZ, the mechanical grinding plate includes a non-woven grinding plate 110 and a needle brush grinding plate 120 in sequence. In some applications, refer to Figure 2 For thick copper plates above 1.5OZ, the mechanical grinding adopts the sanding belt grinding process 130.

[0043] Optionally, refer to Figure 1 and Figure 2 In the initial water washing, the water washing treatment includes ordinary water washing 210 and ultrasonic water washing 220. It is easy to understand that both ordinary water washing 210 and ultrasonic water washing 220 can effectively remove dust, debris and other residues generated during the mechanical grinding process. Ordinary water washing 210 is suitable for preliminary cleaning of large areas, while ultrasonic water washing 220 can penetrate into the orifices and small gaps to remove hard-to-reach residues and ensure thorough cleaning of the surface of the circuit board. In some applications, the water washing treatment includes ordinary water washing 210 and ultrasonic water washing 220 performed sequentially. Among them, ultrasonic water washing 220 uses the cavitation effect generated by high-frequency vibration to effectively remove tiny particles from the orifices and surfaces, improve the cleaning effect, provide a clean base for chemical micro-etching, ensure that the chemical solution can act evenly on the orifices and surfaces, and improve the effect and consistency of chemical micro-etching.

[0044] The circuit board according to the embodiment of the present invention applies a process method for removing drilling burrs according to the embodiment of the present invention.

[0045] The circuit board according to the embodiment of the present invention adopts the above-mentioned process method for removing drilling burrs, ensuring that the circuit board is effectively burred during the manufacturing process. This improvement significantly improves the quality and reliability of the circuit board, reduces the defect rate, reduces production costs, and improves overall production efficiency and market competitiveness.

[0046] Other structures and operations of the circuit board according to the embodiment of the present invention are known to those skilled in the art and will not be described in detail here.

[0047] The embodiments of the present invention are described in detail above with reference to the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge scope of ordinary technicians in the relevant technical field without departing from the purpose of the present invention.

Claims

1. A process for removing drilling burrs, characterized in that: include: Mechanical grinding: After drilling holes in the circuit board, the circuit board is subjected to grinding treatment; Initial water washing: After mechanical grinding, the circuit board is washed with water; Chemical micro-etching: After the initial water washing, the circuit board is micro-etched using chemical solutions to etch away the burrs at the openings of the circuit board.

2. A process for removing drilling burrs according to claim 1, characterized in that: In the chemical micro-etching, the chemical solution is a micro-etching solution.

3. The process for removing drilling burrs according to claim 1, characterized in that: In the chemical micro-etching, the micro-etching amount of the micro-etching treatment is A, which satisfies: A≥1 micron.

4. The process for removing drilling burrs according to claim 1, characterized in that: In the chemical micro-etching, the micro-etching amount of the micro-etching treatment is A, which satisfies: A≤5 microns.

5. A process for removing drilling burrs according to claim 3 or 4, characterized in that: Satisfies: 2 microns ≤ A ≤ 3 microns.

6. The process for removing drilling burrs according to claim 1, characterized in that: In the mechanical grinding plate, the grinding plate treatment includes at least one of a non-woven grinding plate, a needle brush grinding plate and a sanding belt grinding plate.

7. The process for removing drilling burrs according to claim 1, characterized in that: In the primary water washing, the water washing treatment includes ordinary water washing and ultrasonic water washing.

8. The process for removing drilling burrs according to claim 1, characterized in that: Also includes: Washing again: After chemical micro-etching, the circuit board is washed with high pressure water.

9. The process for removing drilling burrs according to claim 8, characterized in that: Also includes: Drying: After washing again, the circuit board is dried.

10. A circuit board, characterized in that: A process for removing drilling burrs as described in any one of claims 1 to 9 is used.

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