A method for realizing specified hole copper thickening

Abstract

The application provides a work method for realizing hole copper thickening of a specified hole, which comprises the following steps: drilling holes on a printed circuit board, and realizing hole copper thickening of the specified hole after one-stage exposure and development treatment and two-stage exposure and development treatment; the drilling holes comprise specified drilling holes and general drilling holes, the one-stage exposure and development treatment is used for developing the specified drilling holes, and the two-stage exposure and development treatment is used for developing the specified drilling holes and the general drilling holes. In the application, the processing technology combining the one-stage exposure and development treatment and the two-stage exposure and development treatment is used, so that the height of the bump of the large window is reduced, the grinding difficulty is reduced, the copper thickness of the corner position is increased, the reliability of the corner position is improved, and the purpose of realizing hole copper thickening of the specified hole is achieved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of high-speed printed circuit board manufacturing, and relates to a method for realizing specified hole copper thickening, in particular to a manufacturing method for a printed circuit board under the condition that the specified hole copper has special requirements, that is, the requirements of the hole copper are met without increasing the surface copper and additional copper thinning process. BACKGROUND

[0002] With the increasing power of production devices, the requirements for heat dissipation and current flow of printed circuit boards are also increasing. The horizontal current flow can be realized by increasing the inner layer copper foil, such as using 20Z or 3OZ or more copper foil, but the vertical current flow can only be realized by thickening the electroplated hole copper.

[0003] At present, the existing methods for realizing hole copper thickening include: whole plate surface electroplating, reducing the surface copper by thinning the copper after electroplating to meet the surface copper requirement of etching circuit; multiple selective hole plating (normal windowing), realizing the hole copper thickening of specified holes by more than twice selective hole plating; and multiple selective hole plating (small windowing), realizing the hole copper thickening of specified holes by more than twice selective hole plating.

[0004] However, the existing technology still has the following problems: whole plate surface electroplating, in the case of meeting the requirements of specified hole copper, the surface copper is very thick, the operation difficulty of the copper thinning process is extremely great, and after the copper thinning process, the uniformity of the outer layer copper thickness is very poor, which seriously affects the etching operation of the subsequent process; multiple selective hole plating (normal windowing), the windowing bump stacking method of multiple selective hole plating leads to very thick bumps, and the operation difficulty of the subsequent polishing process is great, and there is a risk of polishing not off or polishing exposing the original; and multiple selective hole plating (small windowing), although this process does not have the problem of multiple selective hole plating windowing bumps, the second windowing process and the following windowing processes have great difficulty, and there are uncontrollable physical property risks at the hole position and many other problems. Therefore, it is urgent to design a method for realizing specified hole copper thickening to overcome the defects of the existing technology and meet the actual application requirements. SUMMARY

[0005] In view of the deficiencies of the prior art, the purpose of the present application is to provide a method for realizing specified hole copper thickening. In the present application, by using a combination of first-level exposure and development processing and second-level exposure and development processing, the height of the large windowing bump is reduced, the polishing difficulty is reduced, the copper thickness of the corner position is increased, the reliability of the corner position is improved, and the purpose of specified hole copper thickening is achieved.

[0006] To achieve this purpose, the present application adopts the following technical solutions:

[0007] The application provides a work method for realizing hole copper thickening of specified holes.

[0008] After drilling holes on a printed circuit board, and after one-stage exposure and development treatment and two-stage exposure and development treatment, hole copper thickening of specified holes is realized; the drilling holes include specified drilling holes and general drilling holes, the one-stage exposure and development treatment is used for developing the specified drilling holes, and the two-stage exposure and development treatment is used for developing the specified drilling holes and the general drilling holes.

[0009] In the application, by using the treatment process combining the one-stage exposure and development treatment and the two-stage exposure and development treatment, not only the height of the bump of the large window is reduced, the difficulty of grinding is reduced, but also the copper thickness of the corner position is increased, the reliability of the corner position is improved, and the purpose of hole copper thickening of specified holes is achieved.

[0010] It should be noted that the size of the drilling hole in the application is determined according to actual data, and all hole diameters are drilled, including specified drilling holes and other non-specified drilling holes, and those skilled in the art should know that the drilling hole can be adjusted according to actual conditions.

[0011] It should be noted that the exposure or development work of the one-stage exposure and development treatment in the application is mainly operated according to the film data, a small window selective plating hole process is adopted, and only the specified hole diameter that needs hole copper thickening is developed.

[0012] It should be noted that the exposure or development work of the two-stage exposure and development treatment in the application is mainly operated according to the film data, a large window selective plating hole process is adopted, and all hole diameters of the drilling holes are developed.

[0013] As a preferred technical solution of the application, the work method further comprises:

[0014] After drilling holes on a printed circuit board, the one-stage exposure and development treatment is performed after one-stage electroplating treatment and one-stage film pressing treatment are sequentially performed;

[0015] After the one-stage exposure and development treatment, the two-stage exposure and development treatment is performed after two-stage electroplating treatment, one-stage glue removal treatment and two-stage film pressing treatment are sequentially performed;

[0016] After the two-stage exposure and development treatment, hole copper thickening of specified holes is realized after three-stage electroplating treatment, two-stage glue removal treatment, hole blocking treatment and grinding treatment are sequentially performed.

[0017] It should be noted that the specific equipment and operation parameters of the one-stage electroplating treatment, the one-stage film pressing treatment, the two-stage electroplating treatment, the one-stage glue removal treatment, the two-stage film pressing treatment, the three-stage electroplating treatment, the two-stage glue removal treatment, the hole blocking treatment and the grinding treatment and the like are not specially limited in the application, and those skilled in the art can adaptively select according to actual conditions.

[0018] As a preferred technical solution of the present invention, the operation method specifically includes:

[0019] (1) Primary electroplating treatment: The primary electroplating treatment specifically includes electroplating thin copper in the designated drill holes and the general drill holes;

[0020] (2) Primary lamination treatment: The primary lamination treatment specifically includes pressing a dry film on the entire surface of the printed circuit board after the treatment in step (1);

[0021] (3) First-level exposure and development processing: The first-level exposure and development processing specifically includes performing small window selective hole plating according to specified data, and performing exposure and development operations on the printed circuit board processed in step (2);

[0022] (4) Secondary electroplating treatment: The secondary electroplating treatment specifically includes electroplating the designated drilled holes in the printed circuit board after the treatment in step (3) to a designated thickness;

[0023] (5) Primary degumming treatment: The primary degumming treatment specifically includes degumming the entire surface of the printed circuit board after treatment in step (4);

[0024] (6) Secondary lamination treatment: The secondary lamination treatment specifically includes pressing a dry film on the entire surface of the printed circuit board after the treatment in step (5);

[0025] (7) Secondary exposure and development processing: The secondary exposure and development processing specifically includes performing large window selective hole plating according to specified data, and performing exposure and development operations on the printed circuit board processed in step (6);

[0026] (8) Three-stage electroplating treatment: The three-stage electroplating treatment specifically includes electroplating the designated drill holes and general drill holes in the printed circuit board after the treatment in step (7) to a designated thickness;

[0027] (9) Secondary degumming treatment: The secondary degumming treatment specifically includes degumming the entire surface of the printed circuit board after the treatment in step (8);

[0028] (10) Hole plugging treatment: The hole plugging treatment specifically includes plugging the designated drill holes and general drill holes on the printed circuit board after the treatment in step (9) with plugging parts;

[0029] (11) Grinding treatment: The grinding treatment specifically includes grinding the bumps of the designated drilled holes on the printed circuit board after the treatment in step (10), wherein the bumps are the remaining bumps after the large window selective hole plating.

[0030] It should be noted that the first-level electroplating treatment in the present invention is the electroplating treatment, which performs degumming, chemical copper removal and electroplating processes on all drilled holes, including electroplating thin copper in the drilled holes for base electroplating; the first-level lamination treatment includes pressing dry film on the entire panel of the printed circuit board; the second-level electroplating treatment is to electroplate the specified drilled holes to the specified thickness according to the actual hole copper requirements; the first-level degumming treatment includes degumming the entire panel of the printed circuit board; the third-level electroplating treatment is to electroplate all drilled holes to the specified thickness according to the actual hole copper requirements; the second-level degumming includes degumming all the board surfaces of the printed circuit board again; the hole plugging treatment includes sealing all holes with materials such as resin; the grinding treatment is mainly used to grind the bumps left after the large window selective hole plating treatment.

[0031] It should be noted that the present invention combines the processing methods of performing primary electroplating, primary lamination, primary exposure and development, secondary electroplating, primary degumming, secondary lamination, secondary exposure and development, tertiary electroplating, secondary degumming, plugging and grinding on the drilled holes, which can make the copper thickness of the specified drilled holes more accurate while reducing the height of the bumps of the large windows and reducing the difficulty of grinding.

[0032] It should be noted that the present invention uses a processing technology that combines a first-level exposure and development process with a second-level exposure and development process, that is, adopts a reasonable arrangement of large and small window selective plating processes, which not only reduces the height of the bumps of the large window and reduces the difficulty of grinding, but also increases the copper thickness coating at the corner position, improves the reliability of the corner position, and achieves the purpose of thickening the copper of the specified hole.

[0033] As a preferred technical solution of the present invention, the diameter of the designated drill hole is 0.3 to 1 mm, for example, it can be 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0034] As a preferred technical solution of the present invention, in step (1), the thickness of the coating treated by the primary electroplating is 0.25 to 0.4 mil, for example, it can be 0.25 mil, 0.27 mil, 0.29 mil, 0.3 mil, 0.31 mil, 0.33 mil, 0.35 mil, 0.36 mil, 0.38 mil, 0.39 mil, 0.4 mil, etc., but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0035] The thickness of the plating layer of the primary electroplating treatment in the application is 0.25-0.4 mil, because in this thickness range, the hole breakage can be avoided and the surface copper is in a reasonable range, if not in this thickness range, the hole breakage or the surface copper is too high will be caused, which affects the subsequent process operation, because the copper thickness in the hole is less than 0.25 mil, there is a risk of being etched during the pre-treatment of the subsequent process micro-etching, which causes the hole breakage, and if the thickness in the hole is higher than 0.4 mil, due to the influence of the through-hole capability, the surface copper needs to be electroplated about 0.6 mil, which will cause the copper thickness to be too high and affect the subsequent process.

[0036] As a preferred technical solution of the application, in step (3), the opening value of the small opening selective plating hole is less than or equal to the diameter of the specified drilling hole, and the difference between the opening value of the small opening selective plating hole and the diameter of the specified drilling hole is 0-1.5 mil, for example, it can be 0 mil, 0.2 mil, 0.4 mil, 0.6 mil, 0.8 mil, 1 mil, 1.2 mil, 1.4 mil, 1.5 mil, etc., but it is not limited to the listed values, and other values not listed in this range are also applicable.

[0037] In the application, the opening value of the small opening selective plating hole is less than or equal to the diameter of the specified drilling hole, and the difference between the opening value of the small opening selective plating hole and the diameter of the specified drilling hole is 0-1.5 mil, because in this diameter difference range, the plating hole can be guaranteed without protrusions, and the plating quality of the plating hole can be guaranteed, if not in this diameter difference range, the plating hole will have too large protrusions and poor plating quality, etc., because when the diameter difference is less than 0 mil, the plating hole will have obvious protrusions at the hole opening, which cannot achieve the function of small window plating small protrusions, and when the difference is controlled to be greater than 1.5 mil, the specified diameter hole will be covered too much, which artificially reduces the hole diameter and increases the difficulty of plating the hole, affecting the plating quality.

[0038] As a preferred technical solution of the application, in step (4), the specified thickness is the specified thickness of the hole copper, and the specified thickness of the hole copper is 0.4-0.65 mm, for example, it can be 0.4 mm, 0.42 mm, 0.46 mm, 0.48 mm, 0.5 mm, 0.52 mm, 0.54 mm, 0.56 mm, 0.58 mm, 0.6 mm, 0.62 mm, 0.64 mm, 0.65 mm, etc., but it is not limited to the listed values, and other values not listed in this range are also applicable.

[0039] As a preferred technical solution of the application, in step (7), the opening value of the large opening selective plating hole is greater than the diameter of the specified drilling hole.

[0040] As a preferred technical solution of the present invention, the difference between the window value of the large window selective plated hole and the aperture of the designated drilled hole is 2 to 3.5 mil, for example, it can be 2mil, 2.2mil, 2.4mil, 2.6mil, 2.8mil, 3mil, 3.2mil, 3.4mil, 3.5mil, etc., but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0041] In the present invention, the window value of the large window selective plated hole is greater than the aperture of the specified drilled hole, and the difference between the window value of the large window selective plated hole and the aperture of the specified drilled hole is 2 to 3.5 mil. Generally, the difference here is 2.5 mil because within the aperture difference range, it can ensure that the convex point of the plated hole is not too large, and the dry film quality of the plated hole can be guaranteed, and the quality of the plated hole can be guaranteed. If it is not within the aperture difference range, it will lead to problems such as excessive convex points or poor lamination quality. This is because the difference value is greater than 3.5 mil, which will cause the convex point to be too large, affecting the post-process grinding process. If the difference value is less than 2 mil, the secondary lamination operation will become more difficult, and there is a risk of pressing the first convex point, affecting the operation efficiency.

[0042] As a preferred technical solution of the present invention, in step (8), the specified thickness is the final hole copper thickness, and the final hole copper thickness is 0.45-0.7 mm, for example, it can be 0.45 mm, 0.48 mm, 0.5 mm, 0.52 mm, 0.54 mm, 0.56 mm, 0.58 mm, 0.6 mm, 0.62 mm, 0.64 mm, 0.66 mm, 0.68 mm, 0.7 mm, etc., but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0043] It should be noted that the final hole copper thickness in the present invention refers to the hole copper thickness of the designated hole after all operations are completed. The thickness here is generally greater than or equal to the required specification of 0.05 mil.

[0044] It should be noted that the aperture of the general drill hole in the present invention is usually different from the aperture of the designated drill hole. The designated drill hole can be processed first through the first-level exposure and development treatment, and then the designated drill hole and the general drill hole can be processed through the second-level exposure and development treatment. Because the difference between the window value of the first-level exposure and development treatment and the aperture of the designated drill hole is small, it will not affect the subsequent processing of the designated drill hole. The difference between the window value of the second-level exposure and development treatment and the aperture of the designated drill hole is large. The bumps left over from the second-level exposure and development treatment can be removed in the subsequent processing, and it will not affect the processing of all holes.

[0045] Compared with the prior art, the present invention has the following beneficial effects:

[0046] In the present application, by using the process of combining the first exposure development process and the second exposure development process, not only the height of the bump of the large window is reduced, the difficulty of polishing is reduced, but also the copper thickness of the corner position is increased, the reliability of the corner position is improved, and the purpose of thickening the copper of the specified hole is achieved. BRIEF DESCRIPTION OF DRAWINGS

[0047] Figure 1 The structure diagram of the printed circuit board for achieving the thickening of the copper of the specified hole is provided for one specific embodiment of the present application;

[0048] Figure 2 The flow chart of the operation method for achieving the thickening of the copper of the specified hole is provided for one specific embodiment of the present application;

[0049] Figure 3 The structure diagram of the printed circuit board after drilling is provided for one specific embodiment of the present application;

[0050] Figure 4 The structure diagram of the printed circuit board after the first electroplating treatment is provided for one specific embodiment of the present application;

[0051] Figure 5 The structure diagram of the printed circuit board after the first film pressing treatment is provided for one specific embodiment of the present application;

[0052] Figure 6 The structure diagram of the printed circuit board after the first exposure development treatment is provided for one specific embodiment of the present application;

[0053] Figure 7 The structure diagram of the printed circuit board after the second electroplating treatment is provided for one specific embodiment of the present application;

[0054] Figure 8 The structure diagram of the printed circuit board after the first degumming treatment is provided for one specific embodiment of the present application;

[0055] Figure 9 The structure diagram of the printed circuit board after the second film pressing treatment is provided for one specific embodiment of the present application;

[0056] Figure 10 The structure diagram of the printed circuit board after the second exposure development treatment is provided for one specific embodiment of the present application;

[0057] Figure 11 The structure diagram of the printed circuit board after the third electroplating treatment is provided for one specific embodiment of the present application;

[0058] Figure 12A schematic structural diagram of a printed circuit board after secondary debonding treatment provided by a specific embodiment of the present invention;

[0059] Figure 13 A schematic structural diagram of a printed circuit board after hole plugging treatment provided in one embodiment of the present invention;

[0060] Figure 14 A schematic structural diagram of a printed circuit board after grinding provided in one embodiment of the present invention;

[0061] Among them, 1-original board; 2-first-level electroplating layer; 3-designated drilling; 4-general drilling; 5-small window plating; 6-large window plating; 7-first-level dry film layer; 8-second-level electroplating layer; 9-second-level dry film layer; 10-third-level electroplating layer; 11-blocking part. DETAILED DESCRIPTION

[0062] It should be understood that, in the description of the present invention, the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, features defined as "first", "second", etc. may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0063] It should be noted that, in the description of the present invention, unless otherwise expressly specified or limited, the terms "disposed," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0064] Those skilled in the art should understand that the present invention must include necessary pipelines, conventional valves and general pump equipment for realizing a complete process, but the above content does not belong to the main invention point of the present invention. Those skilled in the art can add layouts on their own based on the process flow and equipment structure selection, and the present invention does not make special requirements and specific limitations on this.

[0065] The technical solution of the present invention will be further described below with reference to the accompanying drawings and through specific implementation methods.

[0066] In a specific embodiment, the present invention provides a method for thickening copper in a designated hole, the method comprising:

[0067] Drill holes on a printed circuit board, and after a primary exposure and development process and a secondary exposure and development process, the copper thickening of the designated holes is achieved; the drilling includes designated drilling holes 3 and general drilling holes 4, the primary exposure and development process is used to develop the designated drilling holes 3, and the secondary exposure and development process is used to develop the designated drilling holes 3 and the general drilling holes 4.

[0068] In the present invention, by using a processing process that combines a primary exposure and development process with a secondary exposure and development process, not only the height of the bumps of the large window is reduced and the difficulty of grinding is reduced, but also the copper thickness of the corner position is increased, the reliability of the corner position is improved, and the purpose of thickening the copper of the specified hole is achieved.

[0069] In one embodiment, the structural diagram of the printed circuit board processed by the above method is as follows: Figure 1 As shown, the printed circuit board includes an original board 1, and a primary electroplating layer 2 is provided on the surface of the original board 1. The original board 1 is provided with drill holes, which include designated drill holes 3 and general drill holes 4. The inner surface of the designated drill holes 3 is provided with a small window plating layer 5 and a large window plating layer 6 in sequence.

[0070] It should be noted that the size of the drill holes in the present invention is based on actual data, and all hole diameters are drilled, including designated drill holes 3 and other non-designated drill holes (generally drill holes 4). Those skilled in the art should know that the drill holes here can be adjusted according to actual conditions.

[0071] It should be noted that the first-level exposure and development process in the present invention is mainly operated according to the film data, and a small window selective hole plating process is adopted to develop only the specified hole diameter that requires hole copper thickening.

[0072] It should be noted that the exposure or development operation of the secondary exposure and development process in the present invention is mainly operated according to the film data, and a large-window selective hole plating process is adopted to develop the apertures of all drilled holes.

[0073] Furthermore, the operation method includes:

[0074] like Figure 2 As shown, holes are drilled on the printed circuit board. The structural diagram of the printed circuit board after drilling is as shown in FIG. Figure 3 As shown, it undergoes a first-level electroplating process and a first-level lamination process in sequence, and then a first-level exposure and development process;

[0075] After the primary exposure and development process, it undergoes secondary electroplating, primary debonding and secondary lamination, and then secondary exposure and development.

[0076] After the secondary exposure and development treatment, the copper of the designated holes is thickened by the three-level electroplating treatment, the secondary debonding treatment, the hole plugging treatment and the grinding treatment.

[0077] It should be noted that the present invention does not specifically limit the specific equipment and operating parameters of each treatment such as the primary electroplating treatment, the primary lamination treatment, the secondary electroplating treatment, the primary degumming treatment, the secondary lamination treatment, the tertiary electroplating treatment, the secondary degumming treatment, the pore plugging treatment and the grinding treatment, and those skilled in the art can make adaptive choices based on actual conditions.

[0078] Furthermore, the operation method specifically includes:

[0079] (1) Primary electroplating treatment: Thin copper is plated in the designated drilling hole 3 and the general drilling hole 4. The structural diagram of the printed circuit board after the primary electroplating treatment is as follows: Figure 4 As shown, a primary electroplating layer 2 is electroplated on the original plate 1;

[0080] (2) Primary lamination treatment: Dry film is applied to the entire surface of the printed circuit board after the treatment in step (1). The structural diagram of the printed circuit board after the primary lamination treatment is as follows: Figure 5 As shown, a primary dry film layer 7 is provided on the primary electroplating layer 2;

[0081] (3) First-level exposure and development treatment: small window selective plating is performed according to the specified data, and the printed circuit board treated in step (2) is exposed and developed. The structural diagram of the printed circuit board after the first-level exposure and development treatment is as follows Figure 6 As shown, the designated drill hole 3 is developed;

[0082] (4) Secondary electroplating treatment: Electroplating is performed on the designated drill hole 3 in the printed circuit board after the treatment in step (3) to achieve a designated thickness. The structural diagram of the printed circuit board after the secondary electroplating treatment is as follows: Figure 7 As shown, a secondary electroplating layer 8 is electroplated on the surface of the primary electroplating layer 2;

[0083] (5) Primary degumming treatment: The printed circuit board treated in step (4) is subjected to full-surface degumming. The structural diagram of the printed circuit board after the primary degumming treatment is as follows: Figure 8 As shown;

[0084] (6) Secondary lamination treatment: Dry film is applied to the entire surface of the printed circuit board after the treatment in step (5). The structural diagram of the printed circuit board after the secondary lamination treatment is as follows: Figure 9 As shown, a secondary dry film layer 9 is plated on the printed circuit board after the primary debonding treatment;

[0085] (7) Second exposure developing treatment: according to the specified data, large window selective plating holes are selected, and the printed circuit board after step (6) is subjected to exposure developing operation, the structural schematic diagram of the printed circuit board after the second exposure developing treatment is shown in Figure 10 , and the specified drill holes 3 and the general drill holes 4 are developed;

[0086] (8) Third electroplating treatment: the specified drill holes 3 and the general drill holes 4 in the printed circuit board after step (7) are subjected to electroplating to reach the specified thickness, the structural schematic diagram of the printed circuit board after the third electroplating treatment is shown in Figure 11 , and the third electroplating layer 10 is electroplated on the printed circuit board after the second exposure developing treatment;

[0087] (9) Second glue removing treatment: the printed circuit board after step (8) is subjected to full-face glue removing, the structural schematic diagram of the printed circuit board after the second glue removing treatment is shown in Figure 12 ;

[0088] (10) Hole plugging treatment: the specified drill holes 3 and the general drill holes 4 on the printed circuit board after step (9) are plugged by using the plugging piece 11, the structural schematic diagram of the printed circuit board after the hole plugging treatment is shown in Figure 13 ;

[0089] (11) Polishing treatment: the protrusions on the specified drill holes of the printed circuit board after step (10) are polished, the protrusions are the remaining protrusions after the large window selective plating holes, and the structural schematic diagram of the printed circuit board after the polishing treatment is shown in Figure 14 .

[0090] It should be noted that the first electroplating treatment in the present application is the plating electroplating treatment, and the processes of glue removing, chemical copper removing and electroplating are performed on all drill holes, including electroplating thin copper in the drill holes to perform the base electroplating; the first film pressing treatment includes pressing the dry film on the overall board of the printed circuit board; the second electroplating treatment is to electroplate the specified drill holes 3 to the specified thickness according to the actual hole copper demand; the first glue removing treatment includes glue removing operation on the overall board of the printed circuit board; the third electroplating treatment is to electroplate all drill holes to the specified thickness according to the actual hole copper demand; the second glue removing treatment includes glue removing operation on all board surfaces of the printed circuit board again; the hole plugging treatment includes plugging all holes by using the plugging piece 11, such as resin and other materials; and the polishing treatment is mainly used for polishing the protrusions remaining after the large window selective plating hole treatment.

[0091] It should be noted that the present invention performs a combined treatment method of performing a first-level electroplating treatment, a first-level lamination treatment, a first-level exposure and development treatment, a second-level electroplating treatment, a first-level debonding treatment, a second-level lamination treatment, a second-level exposure and development treatment, a third-level electroplating treatment, a second-level debonding treatment, a hole plugging treatment and a grinding treatment on the drilling hole, which can make the copper thickness of the specified drilling hole 3 more accurate while reducing the height of the bump of the large window and reducing the difficulty of grinding.

[0092] It should be noted that the dry film in the present invention refers to an anti-corrosion protective film, and generally a 1.5 mil dry film produced by Hitachi Chemical or DuPont can be used. Those skilled in the art can make an adaptive selection according to actual conditions.

[0093] Furthermore, the diameter of the drill hole 3 is specified to be 0.3 to 1 mm, for example, it can be 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0094] Furthermore, in step (1), the thickness of the coating by the primary electroplating treatment is 0.25 to 0.4 mil, for example, it can be 0.25 mil, 0.27 mil, 0.29 mil, 0.3 mil, 0.31 mil, 0.33 mil, 0.35 mil, 0.36 mil, 0.38 mil, 0.39 mil, 0.4 mil, etc., but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0095] Furthermore, in step (3), the window value of the small window selectively plated hole is less than or equal to the aperture of the specified drill hole 3, and the difference between the window value of the small window selectively plated hole and the aperture of the specified drill hole 3 is 0 to 1.5 mil, for example, it can be 0 mil, 0.2 mil, 0.4 mil, 0.6 mil, 0.8 mil, 1 mil, 1.2 mil, 1.4 mil, 1.5 mil, etc., but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0096] Furthermore, in step (4), the specified thickness is the specified thickness of the hole copper, and the specified thickness of the hole copper is 0.4 to 0.65 mm, for example, it can be 0.4 mm, 0.42 mm, 0.46 mm, 0.48 mm, 0.5 mm, 0.52 mm, 0.54 mm, 0.56 mm, 0.58 mm, 0.6 mm, 0.62 mm, 0.64 mm, 0.65 mm, etc., but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0097] Furthermore, in step (7), the window value of the large window selectively plated hole is larger than the aperture of the designated drilled hole 3 .

[0098] Furthermore, the difference between the window value of the large window selective plated hole and the aperture of the designated drill hole 3 is 2 to 3.5 mil, for example, it can be 2 mil, 2.2 mil, 2.4 mil, 2.6 mil, 2.8 mil, 3 mil, 3.2 mil, 3.4 mil, 3.5 mil, etc., but is not limited to the listed values, and other values ​​not listed within this numerical range are also applicable.

[0099] Furthermore, in step (8), the specified thickness is the final hole copper thickness, and the final hole copper thickness is 0.45 to 0.7 mm, for example, it can be 0.45 mm, 0.48 mm, 0.5 mm, 0.52 mm, 0.54 mm, 0.56 mm, 0.58 mm, 0.6 mm, 0.62 mm, 0.64 mm, 0.66 mm, 0.68 mm, 0.7 mm, etc., but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0100] It should be noted that the final hole copper thickness in the present invention refers to the hole copper thickness of the designated drill hole 3 after all operations are completed. The thickness here is generally greater than or equal to the required specification of 0.05 mil.

[0101] Example 1

[0102] This embodiment provides a method for implementing copper thickening of a specified hole, specifically comprising:

[0103] (1) Primary electroplating treatment: Electroplating thin copper in the designated drilling hole 3 and the general drilling hole 4;

[0104] (2) Primary lamination treatment: Dry lamination is performed on the entire surface of the printed circuit board after treatment in step (1);

[0105] (3) First-level exposure and development processing: small window selective hole plating is performed according to the specified data, and the printed circuit board processed in step (2) is exposed and developed;

[0106] (4) Secondary electroplating treatment: electroplating the designated drilled hole 3 in the printed circuit board treated in step (3) to a designated thickness;

[0107] (5) Primary degumming treatment: degumming the entire surface of the printed circuit board after treatment in step (4);

[0108] (6) Secondary lamination treatment: Dry lamination is performed on the entire surface of the printed circuit board after treatment in step (5);

[0109] (7) Secondary exposure developing treatment: according to the specified data, large window selective plating holes are selected, and the printed circuit board treated in step (6) is subjected to exposure developing operation;

[0110] (8) Tertiary electroplating treatment: the specified drill holes 3 and general drill holes 4 in the printed circuit board treated in step (7) are electroplated to reach the specified thickness;

[0111] (9) Secondary glue removing treatment: the printed circuit board treated in step (8) is subjected to whole surface glue removing;

[0112] (10) Hole plugging treatment: the specified drill holes 3 and general drill holes 4 on the printed circuit board treated in step (9) are plugged by plugging pieces;

[0113] (11) Polishing treatment: the protrusions on the specified drill holes of the printed circuit board treated in step (10) are polished, and the protrusions are the protrusions left after large window selective plating holes.

[0114] In the embodiment, the aperture of the specified drill holes 3 is 0.3 mm; in step (1), the plating layer thickness of the primary electroplating treatment is 0.25 mil; in step (3), the window value of the small window selective plating holes is less than the aperture of the specified drill holes 3, and the difference between the window value of the small window selective plating holes and the aperture of the specified drill holes 3 is 0.6 mil; in step (4), the specified thickness is the specified thickness of the hole copper, and the specified thickness of the hole copper is 0.4 mm; in step (7), the window value of the large window selective plating holes is greater than the aperture of the specified drill holes 3, and the difference between the window value of the large window selective plating holes and the aperture of the specified drill holes 3 is 2 mil; in step (8), the specified thickness is the final hole copper thickness, and the final hole copper thickness is 0.7 mm.

[0115] Embodiment 2

[0116] The embodiment provides a work method for realizing specified hole hole copper thickening, and the difference from the embodiment 1 is that: the aperture of the specified drill holes 3 is 0.8 mm; in step (1), the plating layer thickness of the primary electroplating treatment is 0.3 mil; in step (3), the window value of the small window selective plating holes is equal to the aperture of the specified drill holes 3; in step (4), the specified thickness is the specified thickness of the hole copper, and the specified thickness of the hole copper is 0.5 mm; in step (7), the window value of the large window selective plating holes is greater than the aperture of the specified drill holes 3, and the difference between the window value of the large window selective plating holes and the aperture of the specified drill holes 3 is 2.3 mil; in step (8), the specified thickness is the final hole copper thickness, and the final hole copper thickness is 0.55 mm. The other methods and conditions are the same as those in the embodiment 1.

[0117] Embodiment 3

[0118] The embodiment provides a work method for realizing specified hole copper thickening, and the difference from the embodiment 1 is that the hole diameter of the specified drill hole 3 is 1 mm; in the step (1), the plating layer thickness of the first electroplating treatment is 0.4 mil; in the step (3), the windowing value of the small windowing selective hole plating is less than the hole diameter of the specified drill hole 3, and the difference between the windowing value of the small windowing selective hole plating and the hole diameter of the specified drill hole 3 is 1.5 mil; in the step (4), the specified thickness is the specified thickness of the hole copper, the specified thickness of the hole copper is 0.65 mm; in the step (7), the windowing value of the large windowing selective hole plating is greater than the hole diameter of the specified drill hole 3, and the difference between the windowing value of the large windowing selective hole plating and the hole diameter of the specified drill hole 3 is 3.5 mil; in the step (8), the specified thickness is the final hole copper thickness, and the final hole copper thickness is 0.7 mm. The other methods and conditions are the same as those in the embodiment 1.

[0119] Embodiment 4

[0120] The embodiment provides a work method for realizing specified hole copper thickening, and the difference from the embodiment 1 is that the difference between the windowing value of the small windowing selective hole plating and the hole diameter of the specified drill hole 3 is 1.6 mil, and the other methods and conditions are the same as those in the embodiment 1.

[0121] Embodiment 5

[0122] The embodiment provides a work method for realizing specified hole copper thickening, and the difference from the embodiment 1 is that the difference between the windowing value of the large windowing selective hole plating and the hole diameter of the specified drill hole 3 is 1.8 mil, and the other methods and conditions are the same as those in the embodiment 1.

[0123] Embodiment 6

[0124] The embodiment provides a work method for realizing specified hole copper thickening, and the difference from the embodiment 1 is that the difference between the windowing value of the large windowing selective hole plating and the hole diameter of the specified drill hole 3 is 3.6 mil, and the other methods and conditions are the same as those in the embodiment 1.

[0125] Comparative Example 1

[0126] The comparative example provides a work method for realizing specified hole copper thickening, and the difference from the embodiment 1 is that only one exposure and development treatment (small windowing selective hole plating) is performed, and the other methods and conditions are the same as those in the embodiment 1.

[0127] Comparative Example 2

[0128] The comparative example provides a work method for realizing specified hole copper thickening, and the difference from the embodiment 1 is that only one exposure and development treatment (large windowing selective hole plating) is performed, and the other methods and conditions are the same as those in the embodiment 1.

[0129] Through the test on the hole copper thickness in the embodiment and the comparative example, the results are shown in the following table 1.

[0130] Table 1 Test of hole copper thickness in examples and comparative examples

[0131]

[0132] From the above table 1, it can be seen that:

[0133] By comparing the results of examples 1-3 and example 4, it can be seen that the hole copper test results in examples 1-3 are better than those in example 4, because the application limits the window value of small window selective plating and the aperture difference of specified drill hole 3 to be 0-1.5 mil, so that the hole copper thickness reaches the ideal value, and when the window difference value is greater than 1.5 mil, the plating quality of small window hole plating will be affected, which affects the final hole copper thickness.

[0134] By comparing the results of examples 1-3 and examples 5 and 6, it can be seen that the hole copper test results in examples 1-3 are better than those in examples 5 and 6, because the application limits the window value of large window selective plating and the aperture difference of specified drill hole 3 to be 2-3.5 mil, obviously, too large or too small aperture difference will affect the difficulty of hole plugging bump and secondary film pressing.

[0135] By comparing the results of examples 1-3 and comparative examples 1 and 2, it can be seen that the test results in examples 1-3 are better than those in comparative examples 1 and 2, because the application uses a combination of first and second exposure and development processes, that is, a reasonable ordering of large and small window selective plating processes, which not only reduces the bump height of large window, reduces the difficulty of grinding, but also increases the copper thickness of the corner position, improves the reliability of the corner position, and achieves the purpose of specified hole copper thickening.

[0136] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto. It should be understood by those skilled in the art that any changes or replacements within the technical scope disclosed by the present application can be easily thought of by those skilled in the art, and all fall within the protection scope and disclosure scope of the present application.

Claims

1. A method for achieving copper thickening of a specified hole, characterized in that: The operation method includes: Drill holes on the printed circuit board, and then go through the first-level electroplating process, the first-level lamination process, and the first-level exposure and development process; It undergoes secondary electroplating treatment, primary debonding treatment, secondary lamination treatment, and then secondary exposure and development treatment; After the secondary exposure and development treatment, the copper of the designated hole is thickened by sequentially undergoing a third-level electroplating treatment, a second-level debonding treatment, a hole plugging treatment, and a grinding treatment; The drill holes include designated drill holes and general drill holes, the primary exposure and development process is used to develop the designated drill holes, and the secondary exposure and development process is used to develop the designated drill holes and general drill holes; in: (1) Primary electroplating treatment: The primary electroplating treatment specifically includes electroplating thin copper in the designated drill holes and the general drill holes; (2) Primary lamination treatment: The first-level lamination process specifically includes pressing a dry film on the entire surface of the printed circuit board after the process in step (1); (3) First-level exposure and development processing: The first-level exposure and development process specifically includes performing small window selective hole plating according to specified data, and performing exposure and development operations on the printed circuit board processed in step (2); (4) Secondary electroplating treatment: The secondary electroplating treatment specifically includes electroplating the designated drilled holes in the printed circuit board treated in step (3) to a designated thickness; (5) Primary degumming treatment: The first-level debonding treatment specifically includes debonding the entire surface of the printed circuit board after the treatment in step (4); (6) Secondary lamination treatment: The secondary lamination process specifically includes pressing a dry film on the entire surface of the printed circuit board after the process in step (5); (7) Secondary exposure and development process: The secondary exposure and development process specifically includes performing large window selective hole plating according to specified data, and performing exposure and development operations on the printed circuit board processed in step (6); (8) Three-level electroplating treatment: The three-stage electroplating treatment specifically includes electroplating the designated drill holes and general drill holes in the printed circuit board after the treatment in step (7) to achieve a designated thickness; (9) Secondary degumming treatment: The secondary debonding treatment specifically includes debonding the entire surface of the printed circuit board after the treatment in step (8); (10) Hole plugging treatment: The hole plugging treatment specifically includes plugging the designated drill holes and general drill holes on the printed circuit board after the treatment in step (9) with plugging pieces; (11) Grinding treatment: The grinding process specifically includes grinding the bumps of the designated drilled holes on the printed circuit board after the process in step (10), wherein the bumps are the remaining bumps after the large window selective hole plating.

2. The operation method according to claim 1, characterized in that: The diameter of the designated drilling hole is 0.3-1 mm.

3. The operation method according to claim 1, characterized in that: The thickness of the coating during the primary electroplating process is 0.25-0.4 mil.

4. The operation method according to claim 1, characterized in that: In step (3), the window value of the small window selectively plated hole is less than or equal to the aperture of the designated drill hole, and the difference between the window value of the small window selectively plated hole and the aperture of the designated drill hole is 0-1.5 mil.

5. The operation method according to claim 1, characterized in that: In step (4), the specified thickness is the specified thickness of the hole copper, and the specified thickness of the hole copper is 0.4~0.65mm.

6. The operation method according to claim 1, characterized in that: In step (7), the window value of the large window selectively plated hole is larger than the aperture of the designated drilled hole.

7. The operation method according to claim 6, characterized in that: The difference between the window value of the large window selective plated hole and the aperture of the designated drilled hole is 2-3.5 mil.

8. The operation method according to claim 1, characterized in that: In step (8), the specified thickness is the final hole copper thickness, and the final hole copper thickness is 0.45~0.7mm.

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