Circuit board processing method and circuit board

Abstract

The invention provides a circuit board processing method and a circuit board. The circuit board processing method comprises the following steps: laminating a plurality of substrates to obtain a semi-finished circuit board; drilling the semi-finished circuit board to obtain a to-be-plated hole area; copper ball hole plugging treatment is carried out on the to-be-plated hole area; carrying out electroplating heating treatment on the semi-finished circuit board after the copper balls are plugged into the holes, so that copper-plated layer through holes are formed in the to-be-plated hole area; and carrying out copper ball detection treatment on the through hole of the copper-plated layer. According to the circuit board processing method, the connection stability between the hole wall of the through hole and the copper plating layer is good.

Description

Technical Field

[0001] The present disclosure relates to the technical field of circuit boards, and in particular to a circuit board processing method and a circuit board. Background Art

[0002] A circuit board is a basic electronic device used to connect electronic components and circuits together, and to realize the layout design of complex circuits in electrical and electronic equipment and the transmission of electrical signals. Circuit boards are widely used in consumer electronics, computers, automobiles, medical equipment, aerospace, semiconductors and other fields. Circuit boards are processed using circuit board processing methods.

[0003] In the prior art, the traditional circuit board processing method includes the following steps: S1, immersing the pre-treated circuit board with through holes drilled therein into a pre-dip solution for a first predetermined period of time; S2, placing the circuit board treated with the pre-dip solution into an activated palladium solution for catalytic treatment for a second predetermined period of time, so that a metal palladium film is formed on the inner wall of the through hole; S3, placing the circuit board with a metal palladium film formed on the inner wall of the through hole into the electroplating solution in a copper plating tank for chemical copper plating, so that copper ions are evenly attached to the metal palladium film on the wall of the through hole to form a copper plating layer of a predetermined thickness, such as the Chinese patent No. CN201710760501.3.

[0004] However, since a metal palladium film (i.e., a metal palladium film, Pd) is formed on the inner wall of the through hole, the circuit board with the metal palladium film formed on the inner wall of the through hole is then placed in the electroplating solution in the copper sinking tank for chemical copper deposition, so that the copper ions (i.e., Cu 2+ ) is uniformly attached to the metal palladium film on the wall of the through-hole to form a copper-plated layer of predetermined thickness. According to the principle of substitution reaction, the metal with a more negative position in the potential series can replace the metal with a more positive position. Therefore, the position of palladium and copper in the potential series determines that it is more difficult for palladium to replace copper in the copper ion solution, so that the thickness of the copper-plated layer formed on the metal palladium film on the wall of the through-hole is smaller, so that the copper-plated layer is thinner, thereby making the adhesion of the copper-plated layer on the wall of the through-hole poor, resulting in the copper-plated layer being difficult to adhere to and connect to the wall of the through-hole, and then making the connection stability between the through-hole wall and the copper-plated layer poor. Summary of the invention

[0005] The purpose of the present disclosure is to overcome the deficiencies in the prior art and to provide a circuit board processing method and a circuit board that can improve the connection stability between the through hole wall and the copper plating layer.

[0006] The purpose of this disclosure is achieved through the following technical solutions:

[0007] A circuit board processing method, comprising:

[0008] Performing a pressing process on multiple substrates to obtain a semi-finished circuit board;

[0009] Drilling the semi-finished circuit board to obtain a hole area to be plated;

[0010] Performing copper ball plugging treatment on the hole area to be plated;

[0011] The semi-finished circuit board after the copper ball plugging hole is subjected to electroplating and heating treatment, so that the hole area to be plated forms a copper-plated through hole;

[0012] The copper-plated layer through-hole is subjected to copper ball detection processing.

[0013] In one of the embodiments, the step of laminating a plurality of substrates includes: obtaining a copper clad laminate and cutting the copper clad laminate to obtain a plurality of substrates of predetermined sizes; placing a semi-cured sheet between two adjacent substrates; and laminating the plurality of substrates.

[0014] In one of the embodiments, the step of drilling holes in the semi-finished circuit board is specifically: drilling holes in the semi-finished circuit board using a drill bit device.

[0015] In one embodiment, the step of performing copper ball plugging treatment on the hole area to be plated includes: obtaining a copper ball and polishing the copper ball; cleaning the polished copper ball; and using the cleaned copper ball to perform copper ball plugging treatment on the hole area to be plated.

[0016] In one of the embodiments, the step of electroplating and heating the semi-finished circuit board after the copper ball plugging includes: using an electroplating container to electroplating the semi-finished circuit board after the copper ball plugging; wherein the electroplating container contains an electrolyte, and the electrolyte is used to immerse the semi-finished circuit board after the copper ball plugging; vibrating the electroplating container; and heating the electroplating container.

[0017] In one of the embodiments, the step of heating the electroplating container is specifically as follows: heating the electroplating container with a heating device, the heating temperature is 85°C to 95°C, and the heating time is 20min to 30min.

[0018] In one of the embodiments, the step of performing copper ball detection processing on the copper-plated layer through hole includes: performing a first scanning processing on the copper-plated layer through hole to obtain a first through hole image; comparing the first through hole image with the initial image to determine whether the copper ball exists in the copper-plated layer through hole; if so, performing copper ball removal processing on the copper-plated layer through hole.

[0019] In one of the embodiments, the step of performing copper ball detection on the copper-plated through-hole includes: performing a first scanning process on the copper-plated through-hole to obtain a first through-hole image; comparing the first through-hole image with the initial image to determine whether the copper ball exists in the copper-plated through-hole; if not, performing a secondary copper ball plugging process on the copper-plated through-hole; performing a secondary electroplating process on the semi-finished circuit board after the secondary copper ball plugging; performing a second scanning process on the copper-plated through-hole to obtain a second through-hole image; comparing the second through-hole image with the initial image to determine whether the copper ball exists in the copper-plated through-hole; if so, performing a copper ball removal process on the copper-plated through-hole.

[0020] In one of the embodiments, after the step of performing copper ball detection processing on the copper-plated layer through-holes, the circuit board processing method further includes: performing dry film covering processing on the semi-finished circuit board; performing solder mask processing on the semi-finished circuit board after dry film covering; performing immersion gold processing on the semi-finished circuit board after solder mask processing; and performing molding processing on the semi-finished circuit board after immersion gold processing.

[0021] A circuit board is processed by the circuit board processing method described in any one of the above embodiments.

[0022] Compared with the prior art, the present invention has at least the following advantages:

[0023] The circuit board processing method disclosed in the present invention firstly performs a drilling process on a semi-finished circuit board to obtain a hole area to be plated, so that the hole wall of the hole area to be plated is exposed, which is convenient for the subsequent attachment of copper ions; then, the hole area to be plated is subjected to a copper ball plugging process, and a copper ball is plugged and fixed in the hole area to be plated, so that the copper ball abuts against the hole wall of the hole area to be plated; then, the semi-finished circuit board after the copper ball plugging is subjected to an electroplating heating process, and the semi-finished circuit board is placed in an electrolyte. At this time, the copper ball serves as an anode, so that the copper ball decomposes in the electrolyte to release copper ions, and the hole wall of the hole area to be plated serves as a cathode, and the copper ions are freed to the cathode, so that the copper ions adhere to the hole wall of the hole area to be plated, and the copper ions are in the hole area to be plated. A copper-plated layer is formed on the hole wall, so that a copper-plated through hole (i.e., a through hole) is formed in the hole area to be plated. Under the heating environment, the reaction of copper ions is more complete, so that the thickness of the copper-plated layer formed on the hole wall of the through hole is larger, thereby solving the problem in the prior art that the positions of palladium and copper in the potential series determine that it is difficult for palladium to replace copper in the copper ion solution, and further solving the problem in the prior art that the thickness of the copper-plated layer formed on the metal palladium film on the hole wall of the through hole is small, so that the copper-plated layer formed on the hole wall of the through hole is thicker, so that the adhesion of the copper-plated layer on the hole wall of the through hole is better, so that the copper-plated layer is easier to adhere to and connect to the hole wall of the through hole, and further the connection stability between the hole wall of the through hole and the copper-plated layer is better. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present disclosure and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 The figure is a flow chart of a circuit board processing method according to an embodiment. DETAILED DESCRIPTION

[0026] In order to facilitate the understanding of the present disclosure, the present disclosure will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present disclosure are given in the drawings. However, the present disclosure can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present disclosure more thoroughly and comprehensively understood.

[0027] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only and do not represent the only implementation method.

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present disclosure. The terms used herein in the specification of the present disclosure are only for the purpose of describing specific embodiments and are not intended to limit the present disclosure. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0029] The present invention provides a circuit board processing method, comprising: laminating a plurality of substrates to obtain a semi-finished circuit board; drilling the semi-finished circuit board to obtain a hole area to be plated; plugging the hole area with a copper ball; electroplating and heating the semi-finished circuit board after the copper ball plugging to form a copper-plated layer through hole in the hole area to be plated; and copper ball detection of the copper-plated layer through hole.

[0030] The above-mentioned circuit board processing method first performs a drilling process on the semi-finished circuit board to obtain a hole area to be plated, so that the hole wall of the hole area to be plated is exposed, which is convenient for the subsequent attachment of copper ions; then, the hole area to be plated is subjected to a copper ball plugging process, and the copper ball is inserted and fixed in the hole area to be plated, so that the copper ball abuts against the hole wall of the hole area to be plated; then, the semi-finished circuit board after the copper ball plugging is subjected to an electroplating heating process, and the semi-finished circuit board is placed in an electrolyte. At this time, the copper ball serves as an anode, so that the copper ball decomposes in the electrolyte to release copper ions, and the hole wall of the hole area to be plated serves as a cathode, and the copper ions are freed to the cathode, so that the copper ions adhere to the hole wall of the hole area to be plated, and the copper ions in the hole area to be plated A copper-plated layer is formed on the hole wall so that a copper-plated through hole (i.e., a through hole) is formed in the hole area to be plated. Under a heating environment, the reaction of copper ions is more complete, so that the thickness of the copper-plated layer formed on the hole wall of the through hole is larger, thereby solving the problem in the prior art that the positions of palladium and copper in the potential series determine that it is difficult for palladium to replace copper in the copper ion solution, and further solving the problem in the prior art that the thickness of the copper-plated layer formed on the metal palladium film on the hole wall of the through hole is smaller, so that the copper-plated layer formed on the hole wall of the through hole is thicker, so that the adhesion of the copper-plated layer on the hole wall of the through hole is better, so that the copper-plated layer is easier to adhere to and connect to the hole wall of the through hole, and further the connection stability between the hole wall of the through hole and the copper-plated layer is better.

[0031] In order to better understand the technical solutions and beneficial effects of the present invention, the present invention is further described in detail below in conjunction with specific embodiments:

[0032] like Figure 1 As shown, a circuit board processing method of an embodiment is used to process a circuit board. Further, the circuit board processing method includes part or all of the following steps:

[0033] S101, performing a pressing process on a plurality of substrates to obtain a semi-finished circuit board.

[0034] In this embodiment, a plurality of substrates are pressed together to connect the plurality of substrates to form a semi-finished circuit board.

[0035] S103, drilling the semi-finished circuit board to obtain a hole area to be plated.

[0036] In this embodiment, the semi-finished circuit board is drilled to obtain a hole area to be plated, so that the hole wall of the hole area to be plated is exposed to facilitate the subsequent attachment of copper ions.

[0037] S105, performing copper ball plugging treatment on the hole area to be plated.

[0038] In this embodiment, the hole area to be plated is subjected to copper ball plugging treatment, and the copper ball is plugged and fixed in the hole area to be plated, so that the copper ball abuts against the hole wall of the hole area to be plated.

[0039] S107, performing electroplating and heating treatment on the semi-finished circuit board after the copper ball plugging, so that the hole area to be plated forms a copper-plated through hole.

[0040] In this embodiment, the semi-finished circuit board after the copper ball plugging hole is subjected to electroplating heating treatment, and the semi-finished circuit board is placed in an electrolyte. At this time, the copper ball serves as an anode, so that the copper ball decomposes in the electrolyte to release copper ions, and the hole wall of the hole area to be plated serves as a cathode. The copper ions are freed to the cathode, so that the copper ions adhere to the hole wall of the hole area to be plated, and the copper ions form a copper-plated layer on the hole wall of the hole area to be plated, so that a copper-plated layer through hole (i.e., a through hole) is formed in the hole area to be plated. Under the heating environment, the reaction of the copper ions is more sufficient.

[0041] S109, performing copper ball detection processing on the copper-plated layer through-hole.

[0042] In this embodiment, a copper ball detection process is performed on the copper-plated layer through hole to confirm whether there is a copper ball in the copper-plated layer through hole.

[0043] The above-mentioned circuit board processing method first performs a drilling process on the semi-finished circuit board to obtain a hole area to be plated, so that the hole wall of the hole area to be plated is exposed, which is convenient for the subsequent attachment of copper ions; then, the hole area to be plated is subjected to a copper ball plugging process, and the copper ball is inserted and fixed in the hole area to be plated, so that the copper ball abuts against the hole wall of the hole area to be plated; then, the semi-finished circuit board after the copper ball plugging is subjected to an electroplating heating process, and the semi-finished circuit board is placed in an electrolyte. At this time, the copper ball serves as an anode, so that the copper ball decomposes in the electrolyte to release copper ions, and the hole wall of the hole area to be plated serves as a cathode, and the copper ions are freed to the cathode, so that the copper ions adhere to the hole wall of the hole area to be plated, and the copper ions in the hole area to be plated A copper-plated layer is formed on the hole wall so that a copper-plated through hole (i.e., a through hole) is formed in the hole area to be plated. Under a heating environment, the reaction of copper ions is more complete, so that the thickness of the copper-plated layer formed on the hole wall of the through hole is larger, thereby solving the problem in the prior art that the positions of palladium and copper in the potential series determine that it is difficult for palladium to replace copper in the copper ion solution, and further solving the problem in the prior art that the thickness of the copper-plated layer formed on the metal palladium film on the hole wall of the through hole is smaller, so that the copper-plated layer formed on the hole wall of the through hole is thicker, so that the adhesion of the copper-plated layer on the hole wall of the through hole is better, so that the copper-plated layer is easier to adhere to and connect to the hole wall of the through hole, and further the connection stability between the hole wall of the through hole and the copper-plated layer is better.

[0044] In one of the embodiments, the step of laminating a plurality of substrates includes: obtaining a copper clad laminate and cutting the copper clad laminate to obtain a plurality of substrates of predetermined sizes for subsequent processing; placing a prepreg between two adjacent substrates, that is, placing a prepreg between two adjacent substrates so that the connection reliability between the two adjacent substrates is better, the number of substrates is n, the number of prepregs is n-1, and n is an integer greater than or equal to 3; laminating the plurality of substrates so that the connection between the plurality of substrates is reliable and stable, so that the circuit board has better performance.

[0045] In one embodiment, the step of drilling the semi-finished circuit board is specifically: drilling the semi-finished circuit board using a drilling nozzle device. In this embodiment, the drill bit of the drilling nozzle device is used to drill the pre-drilled area of ​​the semi-finished circuit board to obtain a hole area to be plated, and the hole area to be plated is a through hole to be plated, forming an electrical path on the circuit board, so that the circuit board has better performance.

[0046] In one of the embodiments, the step of performing copper ball plugging treatment on the hole area to be plated includes: obtaining a copper ball and performing a grinding treatment on the copper ball to destroy the protective film layer on the surface of the copper ball to facilitate subsequent electroplating and heating treatment; cleaning the polished copper ball to remove the protective film layer remaining on the surface of the copper ball after grinding to facilitate subsequent electroplating and heating treatment; performing copper ball plugging treatment on the hole area to be plated using the cleaned copper ball, plugging the copper ball into and fixing it in the hole area to be plated, so that the copper ball abuts against the hole wall of the hole area to be plated to facilitate subsequent electroplating and heating treatment.

[0047] In one embodiment, the step of electroplating and heating the semi-finished circuit board after the copper ball plugging hole comprises: electroplating the semi-finished circuit board after the copper ball plugging hole with a plating container; wherein the plating container contains an electrolyte, and the electrolyte is used to immerse the semi-finished circuit board after the copper ball plugging hole, so that the semi-finished circuit board is placed in the electrolyte, at this time, the copper ball acts as an anode, so that the copper ball decomposes in the electrolyte to release copper ions, the hole wall of the hole area to be plated acts as a cathode, and the copper ions are freed to the cathode, so that the copper ions adhere to the hole wall of the hole area to be plated, and the copper ions form a copper-plated layer on the hole wall of the hole area to be plated, so that a copper-plated layer through hole (i.e., a through hole) is formed in the hole area to be plated; the plating container is vibrated to accelerate the movement rate of the copper ions in the electrolyte, so that the copper ions can better adhere to the hole wall of the hole area to be plated; the plating container is heated, and in the heating environment, the reaction of the copper ions is more sufficient, so that the thickness of the copper plating layer formed on the hole wall of the through hole is larger.

[0048] In one embodiment, the step of heating the electroplating container is specifically as follows: using a heating device to heat the electroplating container, the heating temperature is 85°C to 95°C, and the heating time is 20min to 30min. Under the action of suitable temperature and suitable time, the reaction of copper ions is more complete, so that the thickness of the copper plating layer formed on the wall of the through hole is larger.

[0049] In one of the embodiments, the step of performing copper ball detection on the copper-plated through-hole comprises: performing a first scanning process on the copper-plated through-hole to obtain a first through-hole image; comparing the first through-hole image with the initial image to determine whether the copper ball exists in the copper-plated through-hole; if so, performing copper ball removal on the copper-plated through-hole. In this embodiment, the initial image is an image of a semi-finished circuit board after drilling the semi-finished circuit board, and the area to be plated is a blank area; the first through-hole image is compared with the initial image, that is, the copper-plated through-hole of the first through-hole image is compared with the area to be plated of the initial image. If there are black spots in the copper-plated through-hole of the first through-hole image, and the black spots are copper balls, it is determined that there are copper balls in the copper-plated through-hole; then, the copper-plated through-hole is subjected to copper ball removal to remove the copper balls in the copper-plated through-hole, so that the copper balls are recycled for reuse.

[0050] In one of the embodiments, the step of performing copper ball detection on the copper-plated through-hole includes: S1091, performing a first scanning process on the copper-plated through-hole to obtain a first through-hole image; S1092, comparing the first through-hole image with the initial image to determine whether the copper ball exists in the copper-plated through-hole; S1093, if not, performing a secondary copper ball plugging process on the copper-plated through-hole; S1094, performing a secondary electroplating process on the semi-finished circuit board after the secondary copper ball plugging; S1095, performing a second scanning process on the copper-plated through-hole to obtain a second through-hole image; S1096, comparing the second through-hole image with the initial image to determine whether the copper ball exists in the copper-plated through-hole; S1097, if yes, performing copper ball removal process on the copper-plated through-hole. In this embodiment, the first through-hole image is compared with the initial image, that is, the copper-plated through-hole of the first through-hole image is compared with the hole area to be plated of the initial image. If there is no black spot in the copper-plated through-hole of the first through-hole image, it is judged that there is no copper ball in the copper-plated through-hole; then, the copper-plated through-hole is subjected to secondary copper ball plugging treatment, and a new copper ball is plugged and fixed in the hole area to be plated, so that the new copper ball abuts against the hole wall of the hole area to be plated, so as to facilitate the subsequent electroplating and heating treatment; then, the semi-finished circuit board after the secondary copper ball plugging is subjected to secondary electroplating. The copper ball is plated to allow the new copper ball to continue to release copper ions, which is used to ensure the thickness of the copper-plated layer formed on the through-hole wall; then, the second through-hole image is compared with the initial image, that is, the copper-plated through-hole of the second through-hole image is compared with the hole area to be plated of the initial image. If there are black spots in the copper-plated through-hole of the second through-hole image, and the black spots are copper balls, it is judged that there are copper balls in the copper-plated through-hole; then, the copper-plated through-hole is subjected to copper ball removal treatment to remove the copper balls in the copper-plated through-hole, so that the copper balls are recycled for reuse. Further, if not, steps S1093 to S1097 are repeated again.

[0051] In one embodiment, after the step of performing copper ball detection on the copper-plated through-hole, the circuit board processing method further includes: performing dry film covering on the semi-finished circuit board, wherein the dry film covering is performed by attaching a special film to the surface of the semi-finished circuit board, exposing and developing, and forming a desired circuit pattern, so that the circuit integrity of the circuit board is better; performing solder mask treatment on the semi-finished circuit board after dry film covering to form a solder mask layer, wherein the solder mask layer covers the area where soldering is not required, thereby preventing the problem of short circuit caused by connecting parts that should not be soldered by solder when components are soldered on the circuit board, helping to maintain good insulation performance of the circuit board surface and improving the connection reliability of the circuit board; performing immersion gold treatment on the semi-finished circuit board after solder masking, wherein a thin gold layer is deposited on the copper foil surface of the semi-finished circuit board, thereby providing good welding performance, ensuring the firmness and reliability of the welding point, and improving the welding reliability of the circuit board; performing molding treatment on the semi-finished circuit board after immersion gold treatment to improve the reliability of the circuit board.

[0052] Furthermore, in one embodiment, after the step of performing electroplating and heating treatment on the semi-finished circuit board after the copper ball plugging hole is formed to form a copper-plated through hole in the hole area to be plated, the circuit board processing method further includes:

[0053] Performing corona treatment on the surface of the through hole of the copper plated layer;

[0054] Performing resin plugging treatment on the through holes of the copper-plated layer that have been subjected to corona treatment to obtain holes to be back-drilled;

[0055] Place a transparent insulating plate above the hole to be back-drilled, so that the insulating plate fits the semi-finished circuit board;

[0056] The back drilling tool is used to back drill the copper plated through-holes filled with resin through the transparent insulating board.

[0057] Furthermore, corona treatment is performed on the surface of the through hole of the copper-plated layer.

[0058] It can be understood that corona is to use high frequency and high voltage to generate corona discharge in the gap between the discharge knife holder and the blade to form plasma. Its treatment function is to ionize the air between the two poles through discharge, form a plasma zone on the surface of the material, and make the surface of the material non-polar, thereby achieving modification. In addition, the air is ionized in the high-voltage electric field to produce ozone. Ozone is a strong oxidant that can immediately oxidize the surface molecules of the material, converting it from non-polar to polar, and greatly improving the surface tension. In addition, due to the impact of electrons, the organic residues on the hole wall of the copper-plated layer through hole can be effectively cleaned and removed, avoiding the organic residues from squeezing the hole wall of the through hole due to the pressure of the back drill knife during back drilling, thereby damaging the copper-plated layer. In this embodiment, the surface of the copper-plated layer through hole is subjected to corona treatment. By performing corona treatment on the copper-plated layer through hole, the tightness between the resin and the through hole wall can be effectively enhanced, thereby ensuring the back drilling effect after the resin plugging the hole.

[0059] Furthermore, the through holes of the copper-plated layer that have been subjected to the corona treatment are plugged with resin to obtain holes to be back-drilled.

[0060] In this embodiment, the through holes of the copper-plated layer that have been corona treated are plugged with resin to obtain holes to be back-drilled. The through holes are first plugged with resin and then back-drilled. The resin has good adhesion properties and the surface of the resin is soft. It can be better adhered to the contact surface of the back-drilling tool during drilling, reducing the generation of debris in the back-drilled holes, thereby avoiding the problem of blockage in the back drilling of small holes.

[0061] Furthermore, a transparent insulating plate is placed above the hole to be back-drilled, so that the transparent insulating plate is attached to the semi-finished circuit board.

[0062] In this embodiment, a transparent insulating plate is placed above the hole to be back-drilled, so that the transparent insulating plate fits the semi-finished circuit board. By placing a transparent insulating plate above the hole to be back-drilled and fitting the insulating plate to the semi-finished circuit board, the influence of entangled wire and conductive interference on the back-drilling accuracy can be reduced, and the cleanliness of the drill bit can be ensured, and the drilling quality can be ensured. In particular, when the drill bit performs multiple back-drilling, it can ensure that the drill chips are cleaned up during the re-exit process, thereby improving the accuracy of back-drilling.

[0063] Furthermore, a back drill tool is used to back drill the through holes of the copper-plated layer that have been filled with resin through the transparent insulating plate.

[0064] In this embodiment, the back drill tool is used to back drill the copper-plated through hole filled with resin through a transparent insulating plate, and the through hole section that does not play any connection or transmission role is drilled out to avoid problems such as reflection, scattering and delay of high-speed signal transmission. At the same time, through the effect of the transparent insulating plate, the influence of entangled wire and conductive interference on the back drilling accuracy can be reduced, and the cleanliness of the drill bit can be guaranteed, and the drilling quality can be guaranteed. In particular, when the drill bit is back drilled multiple times, it can ensure that the drill cuttings are cleaned up during the re-exit process, thereby improving the accuracy of back drilling.

[0065] Furthermore, in order to more effectively remove the metal chips remaining in the through-holes, in one embodiment, after the step of back-drilling the copper-plated through-holes filled with resin through a transparent insulating board with a back-drill tool, the circuit board processing method also includes: cleaning the metal chips in the copper-plated through-holes.

[0066] It is understandable that after the back drilling process is completed, a small amount of metal shavings are likely to remain in the back-drilled hole. By cleaning the copper-plated through-hole, the metal shavings remaining in the copper-plated through-hole can be effectively removed to avoid the phenomenon that the through-hole diameter is too small. After the back drilling process, the through-hole diameter becomes smaller and is not easy to tin-plate, which leads to the inability to protect the hole copper that should not be etched away.

[0067] In this embodiment, the outer layer of the semi-finished circuit board is covered with a dry film, and an acid etching process is used to perform etching and cleaning of the metal chips remaining in the through-holes of the copper-plated layer after the back drilling process while the circuit pattern of the outer layer is made by pattern transfer. The acid etching process is used to perform etching and cleaning of the metal chips remaining in the through-holes that have been back-drilled more effectively while the circuit pattern of the outer layer is made by pattern transfer, and the dry film can protect the metal layer that does not need to be removed. In addition, since the resin fills the entire through-hole, the copper-plated layer of the hole wall can be protected by plugging the hole with the resin, so that the acid etching process only removes the metal chips remaining after the small hole is back-drilled, and does not affect the copper-plated layer of the hole wall protected by the resin.

[0068] Furthermore, in one of the embodiments, the thickness of the transparent insulating plate is 0.4 mm to 0.6 mm. It is understandable that by placing a transparent insulating plate above the hole to be back-drilled and making the transparent insulating plate fit the semi-finished circuit board, the influence of the entanglement wire and the conductive interference on the back-drilling accuracy can be reduced, the cleanliness of the drill bit can be guaranteed, and the drilling quality can be guaranteed. In particular, when the drill bit performs multiple back-drilling, it can ensure that the drill chips are cleaned up during the re-out process, thereby improving the accuracy of back-drilling. In this embodiment, the thickness of the transparent insulating plate is 0.5 mm. When the drill bit passes through the 0.5 mm insulating plate, the entanglement wire adhering to the drill bit can be more effectively removed, thereby ensuring the cleanliness of the drill bit and improving the accuracy of the back-drilling hole.

[0069] Furthermore, in one of the embodiments, the number of corona treatments in the corona treatment is 1 to 3 times. It is understandable that the increase in the number of corona treatments can improve the roughness of the corona surface, but when the number of corona treatments is too many, a burnt surface is likely to appear and the roughness begins to deteriorate. In this embodiment, the number of corona treatments in the corona treatment operation is 2 times. After the through-hole wall is subjected to 2 corona treatments, the roughness of the through-hole wall can be more effectively improved, thereby enhancing the tightness between the resin and the through-hole, thereby ensuring the back drilling effect after the resin plugging the hole.

[0070] The present disclosure also provides a circuit board, which is processed by the circuit board processing method of any of the above embodiments.

[0071] Compared with the prior art, the present invention has at least the following advantages:

[0072] The circuit board processing method disclosed in the present invention firstly performs a drilling process on a semi-finished circuit board to obtain a hole area to be plated, so that the hole wall of the hole area to be plated is exposed, which is convenient for the subsequent attachment of copper ions; then, the hole area to be plated is subjected to a copper ball plugging process, and a copper ball is plugged and fixed in the hole area to be plated, so that the copper ball abuts against the hole wall of the hole area to be plated; then, the semi-finished circuit board after the copper ball plugging is subjected to an electroplating heating process, and the semi-finished circuit board is placed in an electrolyte. At this time, the copper ball serves as an anode, so that the copper ball decomposes in the electrolyte to release copper ions, and the hole wall of the hole area to be plated serves as a cathode, and the copper ions are freed to the cathode, so that the copper ions adhere to the hole wall of the hole area to be plated, and the copper ions are in the hole area to be plated. A copper-plated layer is formed on the hole wall, so that a copper-plated through hole (i.e., a through hole) is formed in the hole area to be plated. Under the heating environment, the reaction of copper ions is more complete, so that the thickness of the copper-plated layer formed on the hole wall of the through hole is larger, thereby solving the problem in the prior art that the positions of palladium and copper in the potential series determine that it is difficult for palladium to replace copper in the copper ion solution, and further solving the problem in the prior art that the thickness of the copper-plated layer formed on the metal palladium film on the hole wall of the through hole is small, so that the copper-plated layer formed on the hole wall of the through hole is thicker, so that the adhesion of the copper-plated layer on the hole wall of the through hole is better, so that the copper-plated layer is easier to adhere to and connect to the hole wall of the through hole, and further the connection stability between the hole wall of the through hole and the copper-plated layer is better.

[0073] The above-mentioned embodiments only express several implementation methods of the present disclosure, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the disclosed patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present disclosure, and these all belong to the protection scope of the present disclosure. Therefore, the protection scope of the disclosed patent shall be subject to the attached claims.

Claims

1. A circuit board processing method, characterized in that: include: Performing a pressing process on multiple substrates to obtain a semi-finished circuit board; Drilling the semi-finished circuit board to obtain a hole area to be plated; Performing copper ball plugging treatment on the hole area to be plated; The semi-finished circuit board after the copper ball plugging hole is subjected to electroplating and heating treatment, so that the hole area to be plated forms a copper-plated through hole; The copper-plated layer through-hole is subjected to copper ball detection processing.

2. The circuit board processing method according to claim 1, characterized in that: The steps of laminating a plurality of substrates include: Obtaining a copper-clad laminate and cutting the copper-clad laminate to obtain a plurality of substrates of predetermined sizes; Placing a prepreg between two adjacent substrates; The plurality of substrates are subjected to a pressing process.

3. The circuit board processing method according to claim 1, characterized in that: The specific steps of drilling holes in the semi-finished circuit board are as follows: The semi-finished circuit board is drilled using a drilling device.

4. The circuit board processing method according to claim 1, characterized in that: The step of performing copper ball plugging treatment on the hole area to be plated comprises: Obtaining a copper ball and performing a polishing process on the copper ball; Cleaning the polished copper ball; The cleaned copper balls are used to perform copper ball plugging treatment on the hole area to be plated.

5. The circuit board processing method according to claim 1, characterized in that: The step of performing electroplating and heating treatment on the semi-finished circuit board after copper ball plugging comprises: The semi-finished circuit board after the copper ball plugging hole is electroplated by using an electroplating container; wherein the electroplating container contains an electrolyte, and the electrolyte is used to immerse the semi-finished circuit board after the copper ball plugging hole; vibrating the electroplating container; The electroplating container is subjected to a heating treatment.

6. The circuit board processing method according to claim 5, characterized in that: The specific steps of heating the electroplating container are: The electroplating container is heated by a heating device, the heating temperature is 85° C. to 95° C., and the heating time is 20 min to 30 min.

7. The circuit board processing method according to claim 1, characterized in that: The step of performing copper ball detection on the copper-plated through hole comprises: Performing a first scanning process on the copper-plated layer through hole to obtain a first through hole image; Compare the first through-hole image with the initial image to determine whether the copper ball exists in the through-hole of the copper-plated layer; If so, the copper-plated through hole is subjected to a copper ball removal process.

8. The circuit board processing method according to claim 1, characterized in that: The step of performing copper ball detection on the copper-plated through hole comprises: Performing a first scanning process on the copper-plated layer through hole to obtain a first through hole image; Compare the first through-hole image with the initial image to determine whether the copper ball exists in the through-hole of the copper-plated layer; If not, performing a secondary copper ball plugging process on the copper-plated layer through hole; Performing secondary electroplating treatment on the semi-finished circuit board after secondary copper ball plugging; Performing a second scanning process on the copper-plated layer through hole to obtain a second through hole image; Comparing the second through-hole image with the initial image to determine whether the copper ball exists in the through-hole of the copper-plated layer; If so, the copper-plated through hole is subjected to a copper ball removal process.

9. The circuit board processing method according to claim 1, characterized in that: After the step of performing copper ball detection processing on the copper-plated layer through-hole, the circuit board processing method further includes: Performing dry film covering treatment on the semi-finished circuit board; Performing solder resist treatment on the semi-finished circuit board covered with dry film; Performing gold immersion treatment on the semi-finished circuit board after soldering; The semi-finished circuit board after immersion gold is subjected to molding processing.

10. A circuit board, characterized in that: The circuit board is processed by the circuit board processing method according to any one of claims 1 to 9.

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