A method for manufacturing a circuit board with back-drilled resin plugging holes and non-resin plugging holes

Abstract

The present invention relates to a method for manufacturing a circuit board with back-drilled resin plugging holes and non-resin plugging holes. The technical scheme thereof mainly includes: after the whole board is electroplated, the copper layer in a first preset range around the back-drilled holes that need to be non-resin plugging holes is removed to obtain the corresponding hole ring; the through holes that need to be back-drilled are back-drilled; the back-drilled holes that need to be resin plugging holes are plugged; the openings of the back-drilled holes of the non-resin plugging holes are sealed with dry film, and the board surface area without dry film is etched to obtain the graphic circuit of the whole board; the exposed dry film on the graphic circuit is removed to enter the post-process flow; the application has the advantage of avoiding the problem of scratches on the board surface and circuit caused by back drilling after circuit etching.

Description

Technical Field

[0001] The present invention relates to the technical field of circuit board processing, and more particularly to a method for manufacturing a circuit board with back-drilled resin plugging holes and non-resin plugging holes. Background Art

[0002] With the rapid development of the 5G communication industry, the motherboards used in servers and switches in the communication electronics industry have higher and higher requirements for signal integrity. Generally, the back drilling process is used to remove part of the hole copper and ring. Ring refers to an annular copper ring connected to the hole copper, which is set on the surface of the PCB and is also called "hole ring" or "copper ring". The back drilling process removes unnecessary hole copper and hole ring to meet the high-frequency and high-speed performance requirements.

[0003] Back-drilling holes are divided into back-drilling holes that need to be plugged with resin and back-drilling holes that do not need to be plugged with resin. In the current industry, back-drilling of resin-plugged holes is usually performed before circuit etching, and back-drilling of non-resin-plugged holes is usually performed after circuit etching. Therefore, back-drilling is required twice when making circuit boards. And because back-drilling of non-resin-plugged holes is performed after circuit etching, it is inevitable that there will be quality risks such as circuit scratches and peeling during this process, which will cause the corresponding circuit board to be scrapped. Summary of the invention

[0004] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a method for manufacturing a back-drilled resin-plugged via and a non-resin-plugged via circuit board to solve the above technical problems.

[0005] The above technical objectives of the present invention are achieved through the following technical solutions: A method for manufacturing a back-drilled resin plugged via and a non-resin plugged via circuit board, comprising:

[0006] S1. After the whole board is electroplated, the copper layer in a first preset range around the back-drilled hole that needs to be non-resin plugged is removed to obtain a corresponding hole ring;

[0007] S2, back-drilling the through holes that need to be back-drilled;

[0008] S3, plugging the back-drilled holes for resin plugging;

[0009] S4, the opening of the back-drilled hole of the non-resin plug hole is sealed with a dry film, and the board surface area without the dry film is etched to obtain the graphic circuit of the whole board;

[0010] S5, remove the exposed dry film on the graphic circuit and enter the post-process flow.

[0011] For back-drilled holes that are not resin plugged holes, the copper layer in the first preset range outside the back-drilled holes that need to be non-resin plugged holes is removed to generate a hole ring corresponding to the back-drilled holes of the non-resin plugged holes. For back-drilled holes that need to be resin plugged holes, there is no need to generate a hole ring. Back-drilled holes that need to be resin plugged holes and back-drilled holes that need to be non-resin plugged holes are back-drilled uniformly. Since the copper layer in the first preset range outside the back-drilled holes of the non-resin plugged holes has been removed, it is possible to ensure that excess copper at the through-hole opening is removed during back-drilling. And since the back-drilled holes of the resin plugged holes and the back-drilled holes of the non-resin plugged holes are formed through one-time back-drilling, the back-drilling capacity can be increased and the cost can be reduced. After the back-drilled holes of the resin plugged holes are plugged and ground separately, the openings of the back-drilled holes of the non-resin plugged holes are sealed with a dry film, and then negative film graphics are produced. After the dry film on the circuit is removed, the post-process flow can be entered. Since the openings of the back-drilled holes without resin plugging are sealed by dry film in the production of negative film graphics, it is possible to prevent the solution from penetrating into the holes and the crimped back-drilled holes without resin plugging, which may affect the signal transmission and integrity of the PCB board.

[0012] Optionally, removing the copper layer in a first preset range around the back-drilled hole that needs to be non-resin plugged to obtain a corresponding hole ring includes:

[0013] Cover the copper layer with dry film and seal the opening of the back-drilled hole corresponding to the through hole that needs to be plugged with non-resin;

[0014] Exposing and developing the dry film to remove the dry film in a first preset range above the copper layer of the through hole;

[0015] The board surface area without film is etched to obtain the hole ring corresponding to the through hole, and the exposed dry film is removed.

[0016] Since the opening of the through hole corresponding to the back-drilled hole of the non-resin plug hole is covered by a dry film, and the dry film on the copper ring in the first preset range around the back-drilled hole of the non-resin plug hole is removed by exposure and development, and acid etching is performed, the copper layer at the position of the copper ring is etched away, leaving the hole ring of the back-drilled hole mouth of the non-resin plug hole.

[0017] Optionally, exposing and developing the dry film to remove the dry film in a first preset range above the copper layer of the through hole includes:

[0018] Expose the dry film to cure the dry film on the copper layer whose distance from the through hole to the back drill hole is greater than or equal to the first preset distance and less than or equal to the back drill tool diameter, and the dry film on the copper layer whose distance from the outer copper layer to the back drill hole of the non-resin plug hole is greater than the second preset distance;

[0019] The exposed dry film is developed to remove the unexposed dry film.

[0020] The through hole and the dry film around it that is greater than or equal to the first preset distance of the through hole radius and less than or equal to the back drill tool radius are cured by exposure to close the through hole and leave a copper layer of the first preset distance outside the through hole. The dry film in the area where the distance from the copper layer to the back drill hole of the non-resin plug hole is greater than the second preset distance is cured. At this time, the dry film outside the through hole that is greater than the first preset distance and less than the second preset distance is not cured, and can be removed by development and etched away by the chemical solution during etching, so that the through hole corresponding to the back drill hole of the non-resin plug hole can form a hole ring.

[0021] Optionally, the first preset distance is 3-4 mil.

[0022] The first preset area is set to 3-4 mil, which can ensure that the etching solution will not etch the hole ring during etching, and effectively prevent the etching solution from entering the through hole.

[0023] Optionally, the second preset distance is 5-6 mil.

[0024] The second preset distance is set to 5-6 mil, which can facilitate the use of dry film to seal the opening of the back-drilled hole of the non-resin plug hole in the subsequent process.

[0025] Optionally, the process of sealing the opening of the back-drilled hole of the non-resin plug hole with a dry film, etching the board surface area without the dry film, and obtaining the graphic circuit of the whole board includes:

[0026] Cover the copper layer with dry film to seal the opening of the back-drilled hole without resin plugging;

[0027] Expose and develop the dry film to retain the dry film in the circuit pattern area and the back-drilled holes that close the non-resin plug holes;

[0028] The board area without film is etched to obtain the circuit pattern of the whole board.

[0029] The use of dry film to seal the openings of the back-drilled holes of the non-resin plug holes and etching the circuit pattern of the entire board can prevent the solution from penetrating into the back-drilled holes of the non-resin plug holes during circuit pattern etching, thereby affecting the signal transmission and integrity of the PCB board.

[0030] Optionally, the step of exposing and developing the dry film to retain the circuit pattern area and the dry film that seals the back-drilled holes of the non-resin plugged holes includes:

[0031] exposing the dry film of the copper layer at a third preset distance of the back-drilled hole opening of the non-resin plug hole and the copper layer around it that is not etched;

[0032] The exposed dry film is developed to remove the unexposed dry film, and the dry film in the circuit pattern area and the back-drilled hole that closes the non-resin plug hole is retained.

[0033] The dry film seals the opening of the back-drilled hole of the non-resin plug hole and extends to cover the third preset distance on the surrounding unetched copper layer, which can ensure the sealing effect of the dry film on the back-drilled hole of the non-resin plug hole.

[0034] Optionally, the third preset distance is 1-2 mil.

[0035] Setting the third preset distance to 1-2 mil can ensure that the copper layer under the dry film is etched away during etching, and that the solution does not penetrate into the back-drilled hole of the non-resin plug hole.

[0036] Optionally, the exposure energy is 100-120 mj, and the exposure scale is set to 6-7 grids.

[0037] Using appropriate exposure energy and exposure scale grid number can ensure the curing effect of the dry film and prevent the solution from penetrating into the through holes and back-drilled holes of non-resin plug holes.

[0038] Optionally, the developing speed is 3.5 m / min, and the upper and lower pressures are both 1.5 kg / cm 2 .

[0039] Using appropriate developing speed and pressure can ensure that the uncured dry film is separated from the cured dry film.

[0040] In summary, the present invention has the following beneficial effects:

[0041] 1) By back-drilling the back-drilling holes of resin plug holes and non-resin plug holes uniformly, the back-drilling process that originally required two times is combined into one back-drilling, thereby improving the back-drilling production efficiency and reducing costs;

[0042] 2) When making negative pattern, the back-drilled holes of non-resin plug holes are sealed with dry film to prevent the liquid from penetrating into the back-drilled holes of non-resin plug holes, which may affect the signal transmission effect of the PCB board and the integrity of the back-drilled holes of non-resin plug holes;

[0043] 3) By back-drilling before circuit pattern production, the uniformity of copper resolution on the board surface is good, which can greatly improve the back-drilling CPK accuracy of non-resin plug holes (crimp holes) and avoid scratches on the board surface and circuits caused by back-drilling after circuit etching, reducing scrapping and saving costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 It is a flow chart of a method for manufacturing a back-drilled resin plugged via and a non-resin plugged via circuit board in a specific implementation of the present invention;

[0045] Figure 2 It is the production design drawing for the first outer layer negative film pattern production in the specific implementation of the present invention;

[0046] Figure 3 It is a production design drawing for producing the second outer layer negative film pattern in the specific implementation of the present invention. DETAILED DESCRIPTION

[0047] In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings. Several embodiments of the present invention are shown in the accompanying drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein.

[0048] In the present invention, unless otherwise expressly specified and limited, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features.

[0049] The present invention is described in detail below in conjunction with the accompanying drawings and embodiments.

[0050] Embodiment 1

[0051] The present invention provides a method for manufacturing a back-drilled resin plugged via and a non-resin plugged via circuit board, such as Figure 1-3 As shown, including:

[0052] Drilling through holes on laminated circuit boards after previous processing;

[0053] The copper plate is electroplated to form copper holes in the through holes and thicken the copper layer on the board surface;

[0054] Removing the copper layer in a first preset range around the back-drilled hole of the non-resin plug hole to obtain a corresponding hole ring;

[0055] Back drill the through holes that need to be back drilled;

[0056] Plug the back-drilled holes for resin plugging and grind the excess resin outside the plugging hole;

[0057] The opening of the back-drilled hole of the non-resin plug hole is sealed with a dry film, and the board surface area without the dry film is etched to obtain the graphic circuit of the whole board;

[0058] Remove the exposed dry film on the circuit and enter the post-process flow.

[0059] For the back-drilled holes of non-resin plug holes, the copper ring in the first preset range outside the back-drilled holes of the non-resin plug holes is removed to generate the hole ring corresponding to the back-drilled holes of the non-resin plug holes. For the back-drilled holes of the resin plug holes, there is no need to generate the hole ring. The back-drilled holes of the resin plug holes and the back-drilled holes of the non-resin plug holes are back-drilled uniformly. Since the copper ring in the first preset range outside the back-drilled holes of the non-resin plug holes has been removed, it is possible to ensure that the excess copper at the opening of the through hole is removed during the back-drilling. And since the back-drilled holes of the resin plug holes and the back-drilled holes of the non-resin plug holes are formed through one-time back-drilling, the back-drilling capacity can be increased and the cost can be reduced. After the back-drilled holes of the resin plug holes are plugged and ground separately, the openings of the back-drilled holes of the non-resin plug holes are sealed with a dry film, and then negative film graphics are produced. After the dry film on the circuit is removed, the post-process flow can be entered. Since the openings of the back-drilled holes without resin plugging are sealed by dry film in the production of negative film graphics, it is possible to prevent the solution from penetrating into the holes and the crimped back-drilled holes without resin plugging, which may affect the signal transmission and integrity of the PCB board.

[0060] Optionally, removing the copper layer in a first preset range around the back-drilled hole that needs to be non-resin plugged to obtain a corresponding hole ring includes:

[0061] Cover the copper layer with dry film and seal the opening of the back-drilled hole corresponding to the through hole that needs to be plugged with non-resin;

[0062] Exposing and developing the dry film to remove the dry film in a first preset range above the copper layer of the through hole;

[0063] The board surface area without film is etched to obtain the hole ring corresponding to the through hole, and the exposed dry film is removed.

[0064] Since the opening of the through hole corresponding to the back-drilled hole of the non-resin plug hole needs to be covered with a dry film, and the dry film on the copper ring in the first preset range around the back-drilled hole of the non-resin plug hole is removed by exposure and development, and acid etching is performed, the copper layer at the position of the copper ring is etched away, leaving the hole ring of the back-drilled hole mouth of the non-resin plug hole.

[0065] Optionally, exposing and developing the dry film to remove the dry film in a first preset range above the copper layer of the through hole includes:

[0066] Expose the dry film to cure the dry film on the copper layer whose distance from the through hole to the back drill hole is greater than or equal to the first preset distance and less than or equal to the back drill tool diameter, and the dry film on the copper layer whose distance from the outer copper layer to the back drill hole of the non-resin plug hole is greater than the second preset distance;

[0067] The exposed dry film is developed to remove the unexposed dry film.

[0068] The through hole and the dry film around it that is greater than or equal to the first preset distance of the through hole radius and less than or equal to the back drill tool radius are cured by exposure to close the through hole and leave a copper layer of the first preset distance outside the through hole. The dry film in the area where the distance from the copper layer to the back drill hole of the non-resin plug hole is greater than the second preset distance is cured. At this time, the dry film outside the through hole that is greater than the first preset distance and less than the second preset distance is not cured, and can be removed by development and etched away by the chemical solution during etching, so that the through hole corresponding to the back drill hole of the non-resin plug hole can form a hole ring.

[0069] Optionally, the first preset distance is 3-4 mil. In this embodiment, 3.5 mil is selected.

[0070] Optionally, the second preset distance is 5-6 mil. In this embodiment, 5 mil is selected.

[0071] Optionally, the process of sealing the opening of the back-drilled hole of the non-resin plug hole with a dry film, etching the board surface area without the dry film, and obtaining the graphic circuit of the whole board includes:

[0072] Cover the copper layer with dry film to seal the opening of the back-drilled hole without resin plugging;

[0073] Expose and develop the dry film to retain the dry film in the circuit pattern area and the back-drilled holes that close the non-resin plug holes;

[0074] The board area without film is etched to obtain the circuit pattern of the whole board.

[0075] The use of dry film to seal the openings of the back-drilled holes of the non-resin plug holes and etching the circuit pattern of the entire board can prevent the solution from penetrating into the back-drilled holes of the non-resin plug holes during circuit pattern etching, thereby affecting the signal transmission and integrity of the PCB board.

[0076] Optionally, the step of exposing and developing the dry film to retain the circuit pattern area and the dry film that seals the back-drilled holes of the non-resin plugged holes includes:

[0077] exposing the dry film of the copper layer at a third preset distance of the back-drilled hole opening of the non-resin plug hole and the copper layer around it that is not etched;

[0078] The exposed dry film is developed to remove the unexposed dry film, and the dry film in the circuit pattern area and the back-drilled hole that closes the non-resin plug hole is retained.

[0079] The dry film seals the opening of the back-drilled hole of the non-resin plug hole and extends to cover the third preset distance on the surrounding unetched copper layer, which can ensure the sealing effect of the dry film on the back-drilled hole of the non-resin plug hole.

[0080] Optionally, the third preset distance is 1-2 mil. In this embodiment, 2 mil is selected.

[0081] Optionally, the exposure energy is 100-120 mj, and the exposure scale is controlled at 6-7 grids.

[0082] Optionally, the developing speed is 3.5 m / min, and the upper and lower pressures are both 1.5 kg / cm 2 .

[0083] Resin plugging, using aluminum sheet plugging, at least twice plugging, the first plugging is done from the upper surface of the PCB, the plugging speed is 50mm / S, the second plugging is done from the lower surface of the PCB, the plugging speed is 80mm / S, the pressure of the scraper is 7.0Kgf / cm 2 . The stub value of 2-12mil is the most reasonable control range. The simulation verification shows that the effect on signal transmission is small. After the resin plugging, the board is baked at 70℃, 90℃ and 110℃ for 30 minutes respectively. After grinding, the board is baked again at 120℃ for 30 minutes and then at 150℃ for 45 minutes. The thickness of the air guide plate used for resin plugging is 3.0mm, and the ink is Zhendong GSH-00400L ink. Check to ensure that the ink is not too full. Check the inside of the equipment before plugging and clean up the debris.

[0084] In this embodiment, two outer layer negative pattern productions are used. The first outer layer negative pattern production etches out the hole rings of the through holes that do not need to be plugged with resin, so as to facilitate the back drilling of the through holes that are not plugged with resin. The through holes that are plugged with resin do not need to be covered with dry film for protection, so the copper layer on them will be etched away. Therefore, when back drilling is performed, the copper rings of the back drilled holes of the non-resin plugged holes can be retained, while the copper rings in the back drilled holes of the resin plugged holes are removed. By back drilling all the back drilled holes of the resin plugged holes and the back drilled holes of the non-resin plugged holes at one time, the back drilling capacity can be improved and the cost can be reduced.

[0085] In the second outer layer negative film pattern production, the openings of the back-drilled holes of the non-resin plug holes are sealed by dry film to prevent the liquid from entering the back-drilled holes of the non-resin plug holes and affecting the signal transmission of the PCB board and the integrity of the back-drilled holes of the non-resin plug holes. The second outer layer negative film pattern production solved the problem that the original production method could only be carried out using the positive film process.

[0086] And because the back drilling is done before the circuit pattern is made, the uniformity of copper resolution on the board surface is good during back drilling, which can greatly improve the back drilling CPK accuracy of non-tree plug holes (crimp holes). It can avoid the problem of scratches on the board surface and circuits caused by back drilling after circuit etching, reduce scrapping and save costs.

[0087] Embodiment 2

[0088] This embodiment provides a method for manufacturing a back-drilled resin plugged via and a non-resin plugged via circuit board, comprising:

[0089] Drilling through holes on laminated circuit boards after previous processing;

[0090] The copper plate is electroplated to form copper holes in the through holes and thicken the copper layer on the board surface;

[0091] Removing the copper layer in a first preset range around the back-drilled hole of the non-resin plug hole to obtain a corresponding hole ring;

[0092] Back drill the through holes that need to be back drilled;

[0093] Plug the back-drilled holes for resin plugging and grind the excess resin outside the plugging hole;

[0094] The opening of the back-drilled hole of the non-resin plug hole is sealed with a dry film, and the board surface area without the dry film is etched to obtain the graphic circuit of the whole board;

[0095] Remove the exposed dry film on the circuit and enter the post-process flow.

[0096] For the back-drilled holes of non-resin plug holes, the copper ring in the first preset range outside the back-drilled holes of the non-resin plug holes is removed to generate the hole ring corresponding to the back-drilled holes of the non-resin plug holes. For the back-drilled holes of the resin plug holes, there is no need to generate the hole ring. The back-drilled holes of the resin plug holes and the back-drilled holes of the non-resin plug holes are back-drilled uniformly. Since the copper ring in the first preset range outside the back-drilled holes of the non-resin plug holes has been removed, it is possible to ensure that the excess copper at the opening of the through hole is removed during the back-drilling. And since the back-drilled holes of the resin plug holes and the back-drilled holes of the non-resin plug holes are formed through one-time back-drilling, the back-drilling capacity can be increased and the cost can be reduced. After the back-drilled holes of the resin plug holes are plugged and ground separately, the openings of the back-drilled holes of the non-resin plug holes are sealed with a dry film, and then negative film graphics are produced. After the dry film on the circuit is removed, the post-process flow can be entered. Since the openings of the back-drilled holes without resin plugging are sealed by dry film in the production of negative film graphics, it is possible to prevent the solution from penetrating into the holes and the crimped back-drilled holes without resin plugging, which may affect the signal transmission and integrity of the PCB board.

[0097] Optionally, removing the copper ring in a first preset range around the back-drilled hole of the non-resin plug hole to obtain the corresponding hole ring includes:

[0098] The corresponding hole ring is obtained by laser ablating the copper layer in a first preset range around the back-drilled hole of the non-resin plug hole.

[0099] Specifically, by laser ablation of the copper layer around the through hole, the copper ring of the back-drilled hole of the non-resin plug hole whose single side is greater than or equal to the first preset distance and less than or equal to the single side of the back-drill tool diameter, and the copper layer in the area where the distance from the outer copper layer to the back-drilled hole of the non-resin plug hole is greater than the second preset distance are retained.

[0100] Optionally, the first preset distance is 3-4 mil. In this embodiment, 3.5 mil is selected.

[0101] Optionally, the second preset distance is 5-6 mil. In this embodiment, 5 mil is selected.

[0102] Optionally, the process of sealing the opening of the back-drilled hole of the non-resin plug hole with a dry film, etching the board surface area without the dry film, and obtaining the graphic circuit of the whole board includes:

[0103] Cover the copper layer with dry film to seal the opening of the back-drilled hole without resin plugging;

[0104] Expose and develop the dry film to retain the dry film in the circuit pattern area and the back-drilled holes that close the non-resin plug holes;

[0105] The board area without film is etched to obtain the circuit pattern of the whole board.

[0106] The use of dry film to seal the openings of the back-drilled holes of the non-resin plug holes and etching the circuit pattern of the entire board can prevent the solution from penetrating into the back-drilled holes of the non-resin plug holes during circuit pattern etching, thereby affecting the signal transmission and integrity of the PCB board.

[0107] Optionally, the step of exposing and developing the dry film to retain the circuit pattern area and the dry film that seals the back-drilled holes of the non-resin plugged holes includes:

[0108] exposing the dry film of the copper layer at a third preset distance of the back-drilled hole opening of the non-resin plug hole and the copper layer around it that is not etched;

[0109] The exposed dry film is developed to remove the unexposed dry film, and the dry film in the circuit pattern area and the back-drilled hole that closes the non-resin plug hole is retained.

[0110] The dry film seals the opening of the back-drilled hole of the non-resin plug hole and extends to cover the third preset distance on the surrounding unetched copper layer, which can ensure the sealing effect of the dry film on the back-drilled hole of the non-resin plug hole.

[0111] Optionally, the third preset distance is 1-2 mil. In this embodiment, 2 mil is selected.

[0112] Optionally, the exposure energy is 100-120 mj, and the exposure scale is controlled at 6-7 grids.

[0113] Optionally, the developing speed is 3.5 m / min, and the upper and lower pressures are both 1.5 kg / cm 2 .

[0114] Resin plugging, using aluminum sheet plugging, at least twice plugging, the first plugging is done from the upper surface of the PCB, the plugging speed is 50mm / S, the second plugging is done from the lower surface of the PCB, the plugging speed is 80mm / S, the pressure of the scraper is 7.0Kgf / cm 2 . The stub value of 2-12mil is the most reasonable control range. The simulation verification shows that the effect on signal transmission is small. After the resin plugging, the board is baked at 70℃, 90℃ and 110℃ for 30 minutes respectively. After grinding, the board is baked again at 120℃ for 30 minutes and then at 150℃ for 45 minutes. The thickness of the air guide plate used for resin plugging is 3.0mm, and the ink is Zhendong GSH-00400L ink. Check to ensure that the ink is not too full. Check the inside of the equipment before plugging and clean up the debris.

[0115] This embodiment uses only one outer layer negative film pattern production, and the hole ring of the back-drilled hole of the non-resin plug hole is ablated by laser. After back drilling, the back-drilled hole of the non-resin plug hole and the ablation position are sealed by dry film, which can prevent the solution from entering the back-drilled hole of the non-resin plug hole.

[0116] Embodiment 3

[0117] This embodiment provides a method for manufacturing a back-drilled resin-plugged via and a non-resin-plugged via circuit board, comprising: drilling a through hole on a laminated circuit board after previous process processing;

[0118] The copper plate is electroplated to form copper holes in the through holes and thicken the copper layer on the board surface;

[0119] Removing the copper layer in a first preset range around the back-drilled hole of the non-resin plug hole to obtain a corresponding hole ring;

[0120] Back drill the through holes that need to be back drilled;

[0121] Plug the back-drilled holes for resin plugging and grind the excess resin outside the plugging hole;

[0122] The opening of the back-drilled hole of the non-resin plug hole is sealed with a dry film, and the board surface area without the dry film is etched to obtain the graphic circuit of the whole board;

[0123] Remove the exposed dry film on the circuit and enter the post-process flow.

[0124] For the back-drilled holes of non-resin plug holes, the copper ring in the first preset range outside the back-drilled holes of the non-resin plug holes is removed to generate the hole ring corresponding to the back-drilled holes of the non-resin plug holes. For the back-drilled holes of the resin plug holes, there is no need to generate the hole ring. The back-drilled holes of the resin plug holes and the back-drilled holes of the non-resin plug holes are back-drilled uniformly. Since the copper ring in the first preset range outside the back-drilled holes of the non-resin plug holes has been removed, it is possible to ensure that the excess copper at the opening of the through hole is removed during the back-drilling. And since the back-drilled holes of the resin plug holes and the back-drilled holes of the non-resin plug holes are formed through one-time back-drilling, the back-drilling capacity can be increased and the cost can be reduced. After the back-drilled holes of the resin plug holes are plugged and ground separately, the openings of the back-drilled holes of the non-resin plug holes are sealed with a dry film, and then negative film graphics are produced. After the dry film on the circuit is removed, the post-process flow can be entered. Since the openings of the back-drilled holes without resin plugging are sealed by dry film in the production of negative film graphics, it is possible to prevent the solution from penetrating into the holes and the crimped back-drilled holes without resin plugging, which may affect the signal transmission and integrity of the PCB board.

[0125] Optionally, removing the copper ring in a first preset range around the back-drilled hole of the non-resin plug hole to obtain the corresponding hole ring includes:

[0126] The copper layer in a first preset range around the back-drilled hole of the non-resin plug hole is removed by mechanical controlled depth milling to obtain a corresponding hole ring.

[0127] Specifically, the copper layer around the through hole is removed by mechanical controlled depth milling, and the copper ring of the back-drilled hole of the non-resin plug hole whose single side is greater than or equal to the first preset distance and less than or equal to the single side of the back-drill tool diameter, and the copper layer in the area where the distance from the outer copper layer to the back-drilled hole of the non-resin plug hole is greater than the second preset distance are retained.

[0128] Optionally, the first preset distance is 3-4 mil. In this embodiment, 3.5 mil is selected.

[0129] Optionally, the second preset distance is 5-6 mil. In this embodiment, 5 mil is selected.

[0130] Optionally, the process of sealing the opening of the back-drilled hole of the non-resin plug hole with a dry film, etching the board surface area without the dry film, and obtaining the graphic circuit of the whole board includes:

[0131] Cover the copper layer with dry film to seal the opening of the back-drilled hole without resin plugging;

[0132] Expose and develop the dry film to retain the dry film in the circuit pattern area and the back-drilled holes that close the non-resin plug holes;

[0133] The board area without film is etched to obtain the circuit pattern of the whole board.

[0134] The use of dry film to seal the openings of the back-drilled holes of the non-resin plug holes and etching the circuit pattern of the entire board can prevent the solution from penetrating into the back-drilled holes of the non-resin plug holes during circuit pattern etching, thereby affecting the signal transmission and integrity of the PCB board.

[0135] Optionally, the step of exposing and developing the dry film to retain the circuit pattern area and the dry film that seals the back-drilled holes of the non-resin plugged holes includes:

[0136] exposing the dry film of the copper layer at a third preset distance of the back-drilled hole opening of the non-resin plug hole and the copper layer around it that is not etched;

[0137] The exposed dry film is developed to remove the unexposed dry film, and the dry film in the circuit pattern area and the back-drilled hole that closes the non-resin plug hole is retained.

[0138] The dry film seals the opening of the back-drilled hole of the non-resin plug hole and extends to cover the third preset distance on the surrounding unetched copper layer, which can ensure the sealing effect of the dry film on the back-drilled hole of the non-resin plug hole.

[0139] Optionally, the third preset distance is 1-2 mil. In this embodiment, 2 mil is selected.

[0140] Optionally, the exposure energy is 100-120 mj, and the exposure scale is controlled at 6-7 grids.

[0141] Optionally, the developing speed is 3.5 m / min, and the upper and lower pressures are both 1.5 kg / cm 2 .

[0142] Resin plugging, using aluminum sheet plugging, at least twice plugging, the first plugging is done from the upper surface of the PCB, the plugging speed is 50mm / S, the second plugging is done from the lower surface of the PCB, the plugging speed is 80mm / S, the pressure of the scraper is 7.0Kgf / cm 2 . The stub value of 2-12mil is the most reasonable control range. The simulation verification shows that the effect on signal transmission is small. After the resin plugging, the board is baked at 70℃, 90℃ and 110℃ for 30 minutes respectively. After grinding, the board is baked again at 120℃ for 30 minutes and then at 150℃ for 45 minutes. The thickness of the air guide plate used for resin plugging is 3.0mm, and the ink is Zhendong GSH-00400L ink. Check to ensure that the ink is not too full. Check the inside of the equipment before plugging and clean up the debris.

[0143] This embodiment uses only one outer layer negative film pattern production, and the hole ring of the back-drilled hole of the non-resin plug hole is milled out by mechanical depth control. After back drilling, the back-drilled hole of the non-resin plug hole and the milled position are sealed by dry film, which can prevent the solution from entering the back-drilled hole of the non-resin plug hole.

[0144] Embodiment 4

[0145] This embodiment provides a method for manufacturing a double-sided back-drilled resin plugged via and non-resin plugged via circuit board, comprising: drilling through holes on a laminated circuit board after previous process processing;

[0146] The copper plate is electroplated to form copper holes in the through holes and thicken the copper layer on the board surface;

[0147] Removing the copper layer in a first preset range on both upper and lower sides of the outer periphery of the back-drilled hole of the non-resin plug hole to obtain a corresponding hole ring;

[0148] Back drill the through holes that need to be back drilled;

[0149] Plug the back-drilled holes for resin plugging and grind the excess resin outside the plugging hole;

[0150] The openings on both sides of the back-drilled holes of the non-resin plug holes are sealed with dry film, and the board area without dry film is etched to obtain the graphic circuit of the whole board;

[0151] Remove the exposed dry film on the circuit and enter the post-process flow.

[0152] For the back-drilled holes of non-resin plug holes, the copper ring in the first preset range outside the back-drilled holes of the non-resin plug holes is removed to generate the hole ring corresponding to the back-drilled holes of the non-resin plug holes. For the back-drilled holes of the resin plug holes, there is no need to generate the hole ring. The back-drilled holes of the resin plug holes and the back-drilled holes of the non-resin plug holes are back-drilled uniformly. Since the copper ring in the first preset range outside the back-drilled holes of the non-resin plug holes has been removed, it is possible to ensure that the excess copper at the opening of the through hole is removed during the back-drilling. And since the back-drilled holes of the resin plug holes and the back-drilled holes of the non-resin plug holes are formed through one-time back-drilling, the back-drilling capacity can be increased and the cost can be reduced. After the back-drilled holes of the resin plug holes are plugged and ground separately, the openings of the back-drilled holes of the non-resin plug holes are sealed with a dry film, and then negative film graphics are produced. After the dry film on the circuit is removed, the post-process flow can be entered. Since the openings of the back-drilled holes without resin plugging are sealed by dry film in the production of negative film graphics, it is possible to prevent the solution from penetrating into the holes and the crimped back-drilled holes without resin plugging, which may affect the signal transmission and integrity of the PCB board.

[0153] Optionally, removing the copper layer in a first preset range on both upper and lower sides of the periphery of the back-drilled hole of the non-resin plug hole to obtain a corresponding hole ring includes:

[0154] Cover the copper layer with dry film to seal the opening of the back-drilled hole corresponding to the through hole of the non-resin plug hole;

[0155] Expose and develop the dry film to remove the dry film in a first preset range above the copper layer on the upper and lower sides of the through hole;

[0156] The board surface area without film is etched to obtain the hole ring corresponding to the through hole, and the exposed dry film is removed.

[0157] Since the openings on the upper and lower surfaces of the back-drilled hole corresponding to the through hole of the non-resin plug hole are covered with a dry film, and the dry film on the copper ring in the first preset range outside the back-drilled hole of the non-resin plug hole is removed by exposure and development, and acid etching is performed, the copper layer at the position of the copper ring is etched away, leaving the hole ring of the back-drilled hole mouth of the non-resin plug hole.

[0158] Optionally, the exposing and developing the dry film to remove the dry film in a first preset range above the copper layer on the upper and lower surfaces of the through hole includes:

[0159] Expose the dry film to cure the dry film on the upper and lower surfaces of the copper layer where the distance from the through hole to the back drill hole is greater than or equal to the first preset distance and less than or equal to the back drill tool diameter, and the dry film on the upper and lower surfaces of the area where the distance from the outer copper layer to the back drill hole of the non-resin plug hole is greater than the second preset distance;

[0160] The exposed dry film is developed to remove the unexposed dry film.

[0161] The through hole and the dry film around it that is greater than or equal to the first preset distance of the through hole radius and less than or equal to the back drill tool radius are cured by exposure to close the through hole and leave a copper layer of the first preset distance outside the through hole. The dry film in the area where the distance from the copper layer to the back drill hole of the non-resin plug hole is greater than the second preset distance is cured. At this time, the dry film outside the through hole that is greater than the first preset distance and less than the second preset distance is not cured, and can be removed by development and etched away by the chemical solution during etching, so that the through hole corresponding to the back drill hole of the non-resin plug hole can form a hole ring.

[0162] Optionally, the first preset distance is 3-4 mil. In this embodiment, 3.5 mil is selected.

[0163] Optionally, the second preset distance is 5-6 mil. In this embodiment, 5 mil is selected.

[0164] Optionally, the process of sealing the opening of the back-drilled hole of the non-resin plug hole with a dry film, etching the board surface area without the dry film, and obtaining the graphic circuit of the whole board includes:

[0165] Cover the copper layer with dry film to seal the opening of the back-drilled hole without resin plugging;

[0166] Expose and develop the dry film to retain the dry film in the circuit pattern area and the back-drilled holes that close the non-resin plug holes;

[0167] The board area without film is etched to obtain the circuit pattern of the whole board.

[0168] The use of dry film to seal the openings of the back-drilled holes of the non-resin plug holes and etching the circuit pattern of the entire board can prevent the solution from penetrating into the back-drilled holes of the non-resin plug holes during circuit pattern etching, thereby affecting the signal transmission and integrity of the PCB board.

[0169] Optionally, the step of exposing and developing the dry film to retain the dry films on the upper and lower surfaces of the circuit pattern area and the back-drilled holes that seal the non-resin plugged holes includes:

[0170] Expose the dry film of the copper layer at a third preset distance of the openings on the upper and lower surfaces of the back-drilled hole of the non-resin plug hole and the surrounding unetched copper layer;

[0171] The exposed dry film is developed to remove the unexposed dry film, and the dry film in the circuit pattern area and the back-drilled hole that closes the non-resin plug hole is retained.

[0172] The dry film seals the openings on the upper and lower surfaces of the back-drilled hole of the non-resin plug hole and extends to cover the third preset distance on the surrounding unetched copper layer, which can ensure the sealing effect of the dry film on the back-drilled hole of the non-resin plug hole.

[0173] Optionally, the third preset distance is 1-2 mil. In this embodiment, 2 mil is selected.

[0174] Optionally, the exposure energy is 100-120 mj, and the exposure scale is controlled at 6-7 grids.

[0175] Optionally, the developing speed is 3.5 m / min, and the upper and lower pressures are both 1.5 kg / cm 2 .

[0176] In this embodiment, copper rings are etched on both the upper and lower sides of the back-drilled hole of the non-resin plug hole, and after double-sided back drilling, the openings on the upper and lower sides of the back-drilled hole of the non-resin plug hole are sealed with a dry film to produce circuit patterns, thereby completing the non-resin plug back drilling of the same through-hole double-sided back drilling design.

[0177] The invention discloses a method for manufacturing a circuit board with back-drilled resin plug holes and non-resin plug holes. The method completes the manufacturing of back-drilled holes of resin plug holes and back-drilled holes of non-resin plug holes by back-drilling once, thereby improving back-drilling efficiency and reducing costs. When performing negative film pattern manufacturing, the back-drilled holes of non-resin plug holes are sealed by dry film, thereby preventing the infiltration of chemicals into the back-drilled holes of non-resin plug holes, thereby affecting the signal transmission effect of the PCB board and the integrity of the back-drilled holes of non-resin plug holes. By performing back-drilling before circuit pattern manufacturing, the uniformity of copper resolution on the board surface is good, the back-drilled CPK accuracy of non-tree plug holes (crimping holes) can be greatly improved, and the problem of scratches on the board surface and circuits caused by back-drilling after circuit etching can be avoided, thereby reducing scrapping and saving costs.

[0178] The above is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. A method for manufacturing a circuit board with back-drilled resin vias and non-resin vias, characterized in that: include: S1. After the whole board is electroplated, the copper layer in a first preset range around the back-drilled hole that needs to be non-resin plugged is removed to obtain a corresponding hole ring; S2, back-drilling the through holes that need to be back-drilled; S3, plugging the back-drilled holes for resin plugging; S4, the opening of the back-drilled hole of the non-resin plug hole is sealed with a dry film, and the board surface area without the dry film is etched to obtain the graphic circuit of the whole board; S5, remove the exposed dry film on the graphic circuit and enter the post-process flow.

2. The method for manufacturing a circuit board with back-drilled resin vias and non-resin vias according to claim 1, characterized in that: The step of removing the copper layer in a first preset range around the back-drilled hole that needs to be non-resin plugged to obtain a corresponding hole ring includes: Cover the copper layer with dry film and seal the opening of the back-drilled hole corresponding to the through hole that needs to be plugged with non-resin; Exposing and developing the dry film to remove the dry film in a first preset range above the copper layer of the through hole; The board surface area without film is etched to obtain the hole ring corresponding to the through hole, and the exposed dry film is removed.

3. The method for manufacturing a circuit board with back-drilled resin vias and non-resin vias according to claim 2, characterized in that: Exposing and developing the dry film to remove the dry film in a first preset range above the copper layer of the through hole includes: Expose the dry film to cure the dry film on the copper layer whose distance from the through hole to the back drill hole is greater than or equal to the first preset distance and less than or equal to the back drill tool diameter, and the dry film on the copper layer whose distance from the outer copper layer to the back drill hole of the non-resin plug hole is greater than the second preset distance; The exposed dry film is developed to remove the unexposed dry film.

4. The method for manufacturing a circuit board with back-drilled resin vias and non-resin vias according to claim 3, characterized in that: The first preset distance is 3-4 mil.

5. The method for manufacturing a circuit board with back-drilled resin vias and non-resin vias according to claim 3, characterized in that: The second preset distance is 5-6 mil.

6. The method for manufacturing a circuit board with back-drilled resin vias and non-resin vias according to claim 1, characterized in that: The method of sealing the opening of the back-drilled hole of the non-resin plug hole with a dry film, etching the board surface area without the dry film, and obtaining the graphic circuit of the whole board includes: Cover the copper layer with dry film to seal the opening of the back-drilled hole without resin plugging; Expose and develop the dry film to retain the dry film in the circuit pattern area and the back-drilled holes that close the non-resin plug holes; The board area without film is etched to obtain the circuit pattern of the whole board.

7. The method for manufacturing a circuit board with back-drilled resin vias and non-resin vias according to claim 6, characterized in that: The method of exposing and developing the dry film to retain the circuit pattern area and the dry film of the back-drilled hole that closes the non-resin plug hole includes: exposing the dry film of the copper layer at a third preset distance of the back-drilled hole opening of the non-resin plug hole and the copper layer around it that is not etched; The exposed dry film is developed to remove the unexposed dry film, and the dry film in the circuit pattern area and the back-drilled hole that closes the non-resin plug hole is retained.

8. The method for manufacturing a circuit board with back-drilled resin vias and non-resin vias according to claim 7, characterized in that: The third preset distance is 1-2 mil.

9. A method for manufacturing a back-drilled resin via and non-resin via circuit board according to claim 2 or 6, characterized in that: The exposure energy is 100-120 mj, and the exposure scale is set to 6-7 grids.

10. A method for manufacturing a back-drilled resin via and non-resin via circuit board according to claim 2 or 6, characterized in that: The developing speed is 3.5m / min, and the upper and lower pressures are both 1.5kg / cm 2 .

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