HDI circuit board manufacturing method and device and printed circuit board

Abstract

The invention relates to an HDI circuit board manufacturing method, an HDI circuit board manufacturing device and a printed circuit board, the steps of blind hole drilling, first copper making, first copper reduction, first through hole drilling, second copper making, resin hole plugging, second copper reduction, third copper making and the like are sequentially carried out on a multi-layer PCB, and high vertical and horizontal blind holes and through holes are manufactured in the multi-layer PCB; a good hole filling effect and through hole copper uniformity with good deep plating capacity are obtained, and the problem that copper thickness is not uniform due to the fact that the deep plating capacity of through holes is insufficient in hole filling and copper plating is effectively solved.

Description

Technical Field

[0001] The embodiments of the present invention relate to the technical field of PCB manufacturing, and in particular to a method and device for manufacturing an HDI circuit board and a printed circuit board. Background Art

[0002] HDI circuit board is a high-density interconnection circuit board. HDI circuit board is a circuit board with a relatively high line distribution density using micro blind buried hole technology. It is a compact product designed for small-capacity users, with the characteristics of high density, high precision, and high performance. As electronic products develop towards multi-function, complexity, and miniaturization, HDI circuit boards are increasingly widely used.

[0003] With the development of integrated circuits, more and more high aspect ratio circuit boards are being used. In the circuit board manufacturing industry, high aspect ratio refers to products with an aperture of ≤0.2mm and an aspect ratio of ≥15:1. The difficulty in the hole metallization electroplating process is relatively high, mainly reflected in the large difference in the copper plating rate between the hole mouth and the hole. The copper plating rate at the hole mouth is fast, and the copper plating rate in the middle of the hole is slow, resulting in a large difference in copper thickness between the hole mouth and the middle of the hole, affecting the quality and reliability of the hole copper, such as uneven ductility of the hole copper, uneven copper thickness, resistance and signal impedance problems, and the problem of small hole diameter affecting the difficulty of the resin plugging process, and even causing poor plugging quality problems.

[0004] In the HDI circuit board with high aspect ratio, through-hole and blind-hole are also plated together. Some quality problems often occur in the production process, such as poor hole copper uniformity, small hole diameter, uneven hole copper ductility, poor resin plugging, etc. The higher the aspect ratio of the blind-hole and through-hole copper-plated circuit board, the more serious the problems will be. Summary of the invention

[0005] In view of the above problems, the embodiments of the present invention provide a method, device and printed circuit board for manufacturing an HDI circuit board, which are used to solve the problem that in the prior art, HDI circuit boards with high aspect ratios are also plated with through holes and blind holes, and some quality problems often occur during the production process, such as poor hole copper uniformity, small hole diameter, uneven hole copper ductility, poor resin plugging, etc. The higher the aspect ratio of the blind hole and through hole copper plating circuit board, the more serious the problem.

[0006] According to one aspect of an embodiment of the present invention, a method for manufacturing an HDI circuit board is provided, the method comprising: Drilling blind holes, obtaining a PCB multilayer board and making blind holes in the PCB multilayer board; The first copper making process is to make the first copper surface on the PCB multilayer board by copper deposition and copper plating in sequence, wherein the copper plating solution in the copper plating method is a hole filling solution; The first copper reduction is to reduce the copper on the first surface; Drilling a through hole for the first time to make a first through hole on the PCB multilayer board; The second copper making process is to make the second copper surface on the PCB multilayer board in turn by copper deposition, flash copper plating and pulse electroplating, wherein the copper plating solution in the flash copper plating and pulse electroplating is a non-hole filling solution; Filling the first through hole with resin; The second copper reduction is to reduce copper in the cover hole area of ​​the PCB multilayer board, wherein the cover hole area is the area connected to the first through hole; The third copper making process is to sequentially make a hole-covering copper layer in the hole-covering area by copper deposition, copper flash plating and pulse electroplating, wherein the copper plating solution in the copper flash plating and pulse electroplating is a non-hole-filling solution.

[0007] In some optional embodiments, the first copper reduction specifically includes: In the first grinding, the copper on the first surface is ground to reduce the copper by 2μm-4μm, and the grinding is performed twice with a current of 1.8A, a grinding scar width of 5mm±2mm, and a brushing time of 2 seconds; The first micro-etching is to micro-etch the first copper surface to reduce the copper thickness by 22 μm.

[0008] In some optional embodiments, the second copper reduction specifically includes: The second grinding is to grind off the excess resin of the resin plug hole and grind off the copper on the second side of the cover hole area to reduce the copper thickness by 2 μm-4 μm. The grinding is performed 3 times with a current of 1.8 A, a grinding scar width of 5 mm ± 2 mm, and a brushing time of 2 seconds. The second micro-etching is to micro-etch the cover hole area to reduce copper, and the copper reduction thickness is 10μm-20μm; The third grinding is to grind the resin protruding after the second micro-etching flat, and the grinding is performed once with a current of 1.8A, a grinding scar width of 5mm±2mm, and a brushing time of 2 seconds.

[0009] In some optional embodiments, the drilling of blind holes specifically includes: Laser blind vias, laser-drilling blind vias in the PCB multilayer board; The first plasma debonding removes excess resin in the blind hole.

[0010] In some optional embodiments, after the second copper reduction and before the third copper production, the process further includes: Drilling a through hole for the second time to make a second through hole on the PCB multilayer board; The second plasma debonding is performed to remove excess resin in the second through hole.

[0011] In some optional embodiments, the pore-filling solution is composed of 9%-11% H 2 SO 4 , 5.75%-6.25% CU2+, 1.125%-1.575% leveling agent, 1.125%-1.575% brightener, and 50-70PPM CL-.

[0012] In some optional embodiments, the non-hole-filling solution is composed of 22.5%-27% H 2 SO 4 , 3.375%-4.15% CU2+, 0.85%-1.15% leveling agent, 0.055%-0.105% brightener, 0.75-1.25 leveling agent, and 50-70PPM CL-.

[0013] In some optional embodiments, the second copper-making and third copper-making pulse electroplating include 6 stages, specifically including: The first stage, accounting for 15% of the entire pulse plating cycle, uses 100% positive current for pulse plating; The second stage, which accounts for 30% of the entire pulse plating cycle, uses a positive and negative current ratio of 1:3 and a positive and negative current time ratio of 20:1; The third stage, which accounts for 25% of the entire pulse plating cycle, uses a positive and negative current ratio of 1:3 and a positive and negative current time ratio of 18:9; The fourth stage, which accounts for 10% of the entire pulse plating cycle, uses a positive and negative current ratio of 1:2 and a positive and negative current time ratio of 16:8; The fifth stage, which accounts for 15% of the entire pulse plating cycle, uses a positive and negative current ratio of 1:2 and a positive and negative current time ratio of 14:7; The sixth stage, accounting for 15% of the entire pulse plating cycle, uses 100% positive current for pulse plating.

[0014] According to another aspect of an embodiment of the present invention, there is provided an HDI circuit board manufacturing device, the device being used to execute the above HDI circuit board manufacturing method to manufacture a printed circuit board.

[0015] According to another aspect of an embodiment of the present invention, a printed circuit board is provided. The printed circuit board is manufactured by executing the above-mentioned HDI circuit board manufacturing method using the above-mentioned HDI circuit board manufacturing device.

[0016] The HDI circuit board manufacturing method, device and printed circuit board of the present invention have the beneficial effects that: the present invention manufactures high vertical and horizontal blind holes and through holes in the PCB multilayer board by sequentially performing the steps of drilling blind holes, first copper preparation, first copper reduction, first through hole drilling, second copper preparation, resin hole plugging, second copper reduction and third copper preparation on the PCB multilayer board; obtains better hole filling effect and copper uniformity of through holes with better deep plating ability, and effectively avoids the problem of uneven copper thickness caused by insufficient deep plating ability of hole filling copper plating and through hole plating.

[0017] The above description is only an overview of the technical solution of the embodiment of the present invention. In order to more clearly understand the technical means of the embodiment of the present invention, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the embodiment of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings are only used to illustrate the embodiments and are not to be considered as limiting the present invention. In addition, the same reference symbols are used to represent the same components throughout the accompanying drawings. In the accompanying drawings: Figure 1 A schematic flow chart of a method for manufacturing an HDI circuit board according to Embodiment 1 of the present invention is shown; Figure 2 A schematic diagram of the process of first copper reduction in Example 1 provided by the present invention is shown; Figure 3 A schematic diagram of the process of the second copper reduction in Example 1 provided by the present invention is shown. DETAILED DESCRIPTION

[0019] Exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein.

[0020] Embodiment 1, See also Figure 1 The embodiment of the present invention provides a method for manufacturing an HDI circuit board, the method comprising: 110, drilling blind holes, obtaining a PCB multilayer board and making blind holes in the PCB multilayer board; in step 110, drilling blind holes specifically includes: laser blind holes, lasering blind holes in the PCB multilayer board by laser; the first plasma degumming, removing excess resin in the blind holes.

[0021] 120, the first copper making, the first copper surface of the PCB multilayer board is made by copper deposition and copper plating in sequence, wherein the copper plating solution in the copper plating method is a hole filling solution; in step 120, the hole filling solution is composed of 9%-11% H 2 SO 4, 5.75%-6.25% CU2+, 1.125%-1.575% leveler, 1.125%-1.575% brightener, 50-70PPM CL-. The filling solution can achieve good quality and high efficiency of blind hole filling.

[0022] 130, first copper reduction, copper reduction of the first surface copper; in step 130, the first copper reduction specifically includes: first grinding, grinding the first surface copper to reduce copper by 2μm-4μm, grinding twice with 1.8A current, 5mm±2mm wear mark width, and 2 seconds brush mark time; first micro-etching, micro-etching the first surface copper to reduce copper, and the copper reduction thickness is 22μm.

[0023] 140, drilling a through hole for the first time, making a first through hole in the PCB multilayer board; in step 140, a through hole can be drilled in the PCB multilayer board by mechanical drilling or laser drilling, wherein the first through hole connects the upper and lower surfaces of the PCB multilayer board.

[0024] 150, the second copper making, the second copper surface of the PCB multilayer board is made by copper deposition, flash copper plating and pulse electroplating in sequence, wherein the copper plating solution in the flash copper plating and pulse electroplating is a non-hole filling solution; in step 150, the non-hole filling solution is composed of 22.5%-27% H 2 SO 4 , 3.375%-4.15% CU2+, 0.85%-1.15% leveler, 0.055%-0.105% brightener, 0.75-1.25 leveler, 50-70PPM CL-. In this step, a low copper ratio is used to reduce the copper electroplating speed in the high current area, reduce the uneven copper electroplating in the high and low current areas, and cooperate with the reverse current in the pulse electroplating process to reduce the thicker copper in the high potential area. This step is used to make the second copper on the outer layer of the first copper surface and thicken the copper coating thickness of the PCB multilayer board.

[0025] 160, filling the first through hole with resin; In step 160, the first through hole is filled with epoxy resin to protect the inner layer circuit of the first through hole.

[0026] 170, the second copper reduction is to reduce the copper in the cover hole area of ​​the PCB multilayer board, wherein the cover hole area is the area connected to the first through hole; in step 170, the second copper reduction specifically includes: the second grinding is to grind off the excess resin of the resin plug hole, and grind off the second surface copper of the cover hole area, the copper reduction thickness is 2μm-4μm, and the grinding is performed 3 times with a current of 1.8A, a grind width of 5mm±2mm, and a brushing time of 2 seconds; the second micro-etching is to micro-etch off the cover hole area to reduce the copper, and the copper reduction thickness is 10μm-20μm; the third grinding is to grind off the resin protruding after the second micro-etching, and the grinding is performed once with a current of 1.8A, a grind width of 5mm±2mm, and a brushing time of 2 seconds.

[0027] 180, the third copper preparation is to sequentially prepare a hole-covering copper layer in the hole-covering area by copper deposition, flash copper plating and pulse electroplating, wherein the copper plating solution in the flash copper plating and pulse electroplating is a non-hole-filling solution. In step 180, the non-hole-filling solution is composed of 22.5%-27% H 2 SO 4 , 3.375%-4.15% CU2+, 0.85%-1.15% leveler, 0.055%-0.105% brightener, 0.75-1.25 leveler, 50-70PPM CL-. In this step, a low copper ratio is used to reduce the copper electroplating speed in the high current area, reduce the uneven copper electroplating in the high and low current areas, and cooperate with the reverse current in the pulse electroplating process to reduce the thicker copper in the high potential area. This step is used to make a cover hole copper layer in the cover hole area to cover the first through hole position. .

[0028] The present invention manufactures high vertical and horizontal blind holes and through holes on a PCB multilayer board by sequentially performing the steps of blind hole drilling, first copper preparation, first copper reduction, first through hole drilling, second copper preparation, resin hole plugging, second copper reduction and third copper preparation on a PCB multilayer board; obtains better hole filling effect and copper uniformity of through holes with better deep plating ability, and effectively avoids the problem of uneven copper thickness caused by insufficient deep plating ability of hole filling copper plating and through hole plating.

[0029] In some optional embodiments, see Figure 2 ,The first copper reduction includes: 210, the first grinding, the first copper surface is ground to reduce copper by 2μm-4μm, and two grindings are performed with 1.8A current, 5mm±2mm wear mark width, and 2 seconds brush mark time; the grinding can be performed by grinding equipment, and the first grinding specifically includes the following steps: according to the high current distribution characteristics of hole filling electroplating, the thicker copper is all at the clamping point position, so in the grinding stage, the product is electroplated with a clamping point on the side of the ceramic grinding wheel, so that the grinding pressure at the position with thicker copper is the largest, and a greater grinding and copper reduction effect is obtained, ensuring that the extreme difference in copper thickness on the entire PCB multilayer board surface is reduced.

[0030] 220, the first micro-etching, the first surface copper is micro-etched to reduce copper, and the copper reduction thickness is 22μm. In this embodiment, the first micro-etching can be performed by a micro-etching solution composed of sulfuric acid, hydrogen peroxide, water-soluble metal salts, micro-etching stabilizers, etc. The micro-etching is specifically performed through the following steps, the product is electroplated with a clamping point on the horizontal production line once, and then the micro-etching copper reduction nozzle pressure is increased according to the thicker copper plating position, and the micro-etching rate of the solution at this position is increased to achieve a more copper reduction effect, thereby reducing the extreme difference in copper thickness of the entire board surface.

[0031] In some optional embodiments, see Figure 3 ,The second copper reduction includes: 310, the second grinding, the excess resin of the resin plug hole is ground flat, and the second side copper of the cover hole area is ground to reduce the copper thickness, the copper reduction thickness is 2μm-4μm, and 3 grindings are performed with 1.8A current, 5mm±2mm wear mark width, and 2 seconds brush mark time; the grinding can be performed by grinding equipment, and the second grinding specifically includes the following steps: according to the high current distribution characteristics of hole filling electroplating, the thicker copper is all at the clamping point position, so in the grinding stage, the product is electroplated with a clamping point on the side of the ceramic grinding wheel, so that the grinding pressure at the position with thicker copper is the largest, and a greater grinding and copper reduction effect is obtained, ensuring that the extreme difference in copper thickness of the entire PCB multi-layer board surface is reduced.

[0032] 320, the second micro-etching, micro-etching copper reduction in the cover hole area, the copper reduction thickness is 10μm -20μm; the second micro-etching can be made by micro-etching solution composed of sulfuric acid, hydrogen peroxide, water-soluble metal salts, micro-etching stabilizers, etc. The micro-etching is specifically carried out through the following steps, the product is electroplated with a clamping point on the horizontal production line once, and then the micro-etching copper reduction nozzle pressure is increased according to the thicker copper plating position, and the micro-etching rate of the solution at this position is increased to achieve a more copper reduction effect, thereby reducing the extreme difference in copper thickness of the entire board surface.

[0033] 330, the third grinding, the resin protruding after the second micro-etching is smoothed, and one grinding is performed through 1.8A current, 5mm±2mm grinding width, and 2 seconds brushing time. The third grinding is used to remove excess resin in the cover hole area to make the surface of the cover hole area flat, which is convenient for the third electroplating.

[0034] In this embodiment, the product is electroplated with one end of the clamping point against the horizontal production line, and then the micro-etching copper reduction nozzle pressure is increased according to the thicker copper plating position, and the micro-etching rate of the solution at this position is increased to achieve a more copper reduction effect, thereby reducing the extreme difference in copper thickness on the entire board surface. The first micro-etching is used to reduce the copper added by the hole filling electroplating, from about 25μm~30μm to 8~10μm. In the first electroplating, the extreme difference in the surface copper thickness is controlled to be ≤5μm. The second micro-etching is used to reduce the copper on the surface copper that needs to be plated for the hole cover, from about 30μm~35μm to 15~20μm. Through the two processes of grinding + micro-etching, the extreme difference in copper thickness on the board surface is controlled within 10μm for the thick copper area to ensure that the fine line meets the etching process capability. In the case of a large deviation in copper thickness or exceeding 10μm, etching will result in an incomplete etching short circuit or excessive etching resulting in a small line.

[0035] In the above embodiment, through the first grinding, the second grinding and the third grinding, according to the high current distribution characteristics of hole filling electroplating or through-hole electroplating, the thicker copper is located at the clamping point. In the grinding stage, the product is plated with a clamping point on one side of the ceramic grinding wheel, so that the grinding pressure at the position with thicker copper is the greatest, and a greater grinding and copper reduction effect is obtained, ensuring that the extreme difference in copper thickness of the entire board surface is reduced.

[0036] In some optional embodiments, drilling blind holes specifically includes: laser blind holes, which are laser-drilled blind holes in a PCB multilayer board by laser; in addition, the blind holes can be made by mechanical drilling.

[0037] The first plasma degumming removes the excess resin in the blind hole. The resin glue remaining after drilling the PCB multilayer board can be degummed by any of the following methods: vacuum plasma cleaning, chemical dissolution, mechanical removal, thermal stripping, and potassium permanganate. In this solution, the epoxy resin glue can be chemically dissolved by organic solvents such as acetone, acetic acid, and methanol to clean the resin glue. Before degumming, the target PTH hole needs to be drilled in the PCB multilayer board. The previous drilling process can be mechanical drilling or laser drilling according to the drilling data.

[0038] In some optional embodiments, after the second copper reduction and before the third copper production, the process further includes: Drill a through hole for the second time to make a second through hole in the PCB multilayer board; this step is used to make a through hole that does not require a cover hole; the second through hole can be made by mechanical drilling or laser drilling.

[0039] The second plasma degumming is used to remove the excess resin in the second through hole. The resin glue remaining after drilling the PCB multilayer board can be degummed by any of the following methods: vacuum plasma cleaning, chemical dissolution, mechanical removal, thermal stripping, and potassium permanganate. In this solution, the epoxy resin glue can be chemically dissolved by organic solvents such as acetone, acetic acid, and methanol to clean the resin glue. Before degumming, the target PTH hole needs to be drilled in the PCB multilayer board. The previous drilling process can be mechanical drilling or laser drilling according to the drilling data.

[0040] In some optional embodiments, the hole filling solution is composed of 9%-11% H 2 SO 4 , 5.75%-6.25% CU2+, 1.125%-1.575% leveler, 1.125%-1.575% brightener, 50-70PPM CL-. In this embodiment, the hole filling electroplating solution ratio is H2SO4: 90-110g / L, CU2+: 57.5-62.5 g / L, CL-: 50-70ppm, leveler: 11.25-15.75ml / L, brightener: 11.25-15.75ml / L. Among them, chloride ions stabilize the quality of copper plating lattice and enhance the ductility of copper plating.

[0041] In some optional embodiments, the non-hole-filling solution is composed of 22.5%-27% H 2 SO 4 , 3.375%-4.15% CU2+, 0.85%-1.15% leveler, 0.055%-0.105% brightener, 0.75-1.25 leveler, 50-70PPM CL-. In this embodiment, the non-hole filling solution is the through-hole plating solution, H2SO4: 250-270g / L, CU2+: 33.75-41.5 g / L, CL-: 50-70ppm, leveler: 8.5-11.5ml / L, brightener: 0.55-1.05ml / L, wetting agent: 7.5-12.5ml / L. Among them, H 2 SO 4 High acid provides a more evenly distributed current and adopts a low copper ratio to reduce the copper electroplating speed in the high current area, reduce the uneven copper electroplating in the high and low current areas, and cooperate with the reverse current in the pulse electroplating process to reduce the thicker copper in the high potential area; chloride ions stabilize the quality of the copper plating lattice and enhance the ductility of the copper plating.

[0042] In some optional embodiments, the second copper plating and the third copper plating pulse plating include 6 stages, among which the main function of PTH is to deposit a thin layer of metal copper on the non-conductive hole wall substrate of the drilled hole by chemical method, which serves as the base for subsequent copper plating. Flash copper plating is to plate a layer of base copper about 5~10μm thick on the surface of the copper deposited in the via hole, so that the VCP can be pre-treated with oil, micro-etching, and pickling to ensure that the deposited copper is intact. It specifically includes: The first stage, accounting for 15% of the entire pulse plating cycle, uses 100% positive current for pulse plating; The second stage, which accounts for 30% of the entire pulse plating cycle, uses a positive and negative current ratio of 1:3 and a positive and negative current time ratio of 20:1; The third stage, which accounts for 25% of the entire pulse plating cycle, uses a positive and negative current ratio of 1:3 and a positive and negative current time ratio of 18:9; The fourth stage, which accounts for 10% of the entire pulse plating cycle, uses a positive and negative current ratio of 1:2 and a positive and negative current time ratio of 16:8; The fifth stage, which accounts for 15% of the entire pulse plating cycle, uses a positive and negative current ratio of 1:2 and a positive and negative current time ratio of 14:7; The sixth stage, accounting for 15% of the entire pulse plating cycle, uses 100% positive current for pulse plating.

[0043] See Table 1 below. Table 1 shows pulse electroplating parameters, which can achieve uniform copper plating and copper plating thickness that meets requirements in the second copper plating or the third copper plating.

[0044]

[0045] Table 1 Embodiment 2: According to another aspect of an embodiment of the present invention, there is provided an HDI circuit board manufacturing device, which is used to execute the above HDI circuit board manufacturing method to manufacture a printed circuit board.

[0046] The following steps can be performed by the device of this application: Drilling blind holes, obtaining a PCB multilayer board and making blind holes in the PCB multilayer board; The first copper making process is to make the first copper surface on the PCB multilayer board by copper deposition and copper plating in sequence, wherein the copper plating solution in the copper plating method is a hole filling solution; The first copper reduction is to reduce the copper on the first surface; Drilling a through hole for the first time to make a first through hole on the PCB multilayer board; The second copper making process is to make the second copper surface on the PCB multilayer board in turn by copper deposition, flash copper plating and pulse electroplating, wherein the copper plating solution in the flash copper plating and pulse electroplating is a non-hole filling solution; Filling the first through hole with resin; The second copper reduction is to reduce copper in the cover hole area of ​​the PCB multilayer board, wherein the cover hole area is the area connected to the first through hole; The third copper making process is to sequentially make a hole-covering copper layer in the hole-covering area by copper deposition, copper flash plating and pulse electroplating, wherein the copper plating solution in the copper flash plating and pulse electroplating is a non-hole-filling solution.

[0047] The present invention separates the steps of making blind holes and through holes, and performs copper plating of blind holes and through holes in a step-by-step manner in a hole-filling plating solution, a high aspect ratio copper plating solution, and a pulse electroplating process, thereby avoiding the problem of uneven copper thickness caused by insufficient deep plating capacity of hole-filling copper plating and through-hole plating. In addition, after multiple copper platings, the copper thickness of the board surface exceeds the control requirements, and the copper in excess thickness is removed by special grinding and micro-etching copper reduction processes, so as to achieve the surface copper extreme difference that can be allowed in the subsequent etching process.

[0048] Embodiment 3: According to another aspect of the embodiment of the present invention, a printed circuit board is provided, and the printed circuit board is manufactured by executing the above-mentioned HDI circuit board manufacturing method through the above-mentioned HDI circuit board manufacturing device. The HDI circuit board manufacturing method, device and printed circuit board of the present invention have the following beneficial effects: the present invention manufactures high vertical and horizontal blind holes and through holes in the PCB multilayer board by sequentially performing the steps of drilling blind holes, first copper making, first copper reduction, first through hole drilling, second copper making, resin plugging holes, second copper reduction and third copper making on the PCB multilayer board; obtains better hole filling effect and copper uniformity of through holes with better deep plating ability, and effectively avoids the problem of uneven copper thickness caused by insufficient deep plating ability of hole filling copper plating and through hole plating.

[0049] In the description provided herein, a large number of specific details are described. However, it is understood that embodiments of the present invention can be practiced without these specific details. Similarly, in order to simplify the present invention and help understand one or more of the various inventive aspects, in the above description of exemplary embodiments of the present invention, the various features of the embodiments of the present invention are sometimes grouped together into a single embodiment, figure, or description thereof. Wherein, the claims that follow the specific embodiment are hereby expressly incorporated into the specific embodiment, wherein each claim itself is a separate embodiment of the present invention.

[0050] Those skilled in the art will appreciate that the modules in the devices in the embodiments may be adaptively changed and arranged in one or more devices different from the embodiments. The modules or units or components in the embodiments may be combined into one module or unit or component, and further may be divided into a plurality of submodules or subunits or subcomponents. Except that at least some of such features and / or processes or units are mutually exclusive.

[0051] It should be noted that the above embodiments illustrate the present invention rather than limit it, and that those skilled in the art may design alternative embodiments without departing from the scope of the appended claims. In the claims, any reference symbol between brackets shall not be construed as a limitation on the claims. The word "comprising" does not exclude the presence of elements or steps not listed in the claims. The word "one" or "an" preceding an element does not exclude the presence of multiple such elements. The present invention may be implemented with the aid of hardware comprising several different elements and with the aid of appropriately programmed computers. In a unit claim that lists several systems, several of these systems may be embodied by the same hardware item. The use of the words first, second, and third, etc. does not indicate any order. These words may be interpreted as names. The steps in the above embodiments, unless otherwise specified, should not be understood as limitations on the order of execution.

Claims

1. A method for manufacturing an HDI circuit board, characterized in that: The method comprises: Drilling blind holes, obtaining a PCB multilayer board and making blind holes in the PCB multilayer board; The first copper making process is to make the first copper surface on the PCB multilayer board by copper deposition and copper plating in sequence, wherein the copper plating solution in the copper plating method is a hole filling solution; The first copper reduction is to reduce the copper on the first surface; Drilling a through hole for the first time to make a first through hole on the PCB multilayer board; The second copper making process is to make the second copper surface on the PCB multilayer board in turn by copper deposition, flash copper plating and pulse electroplating, wherein the copper plating solution in the flash copper plating and pulse electroplating is a non-hole filling solution; Filling the first through hole with resin; The second copper reduction is to reduce copper in the cover hole area of ​​the PCB multilayer board, wherein the cover hole area is the area connected to the first through hole; The third copper making process is to sequentially make a hole-covering copper layer in the hole-covering area by copper deposition, copper flash plating and pulse electroplating, wherein the copper plating solution in the copper flash plating and pulse electroplating is a non-hole-filling solution.

2. The HDI circuit board manufacturing method according to claim 1, characterized in that: The first copper reduction specifically includes: In the first grinding, the copper on the first surface is ground to reduce the copper by 2μm-4μm, and the grinding is performed twice with a current of 1.8A, a grinding scar width of 5mm±2mm, and a brushing time of 2 seconds; The first micro-etching is to micro-etch the first copper surface to reduce the copper thickness by 22 μm.

3. The method for manufacturing an HDI circuit board according to claim 1, characterized in that: The second copper reduction specifically includes: The second grinding is to grind off the excess resin of the resin plug hole and grind off the copper on the second side of the cover hole area to reduce the copper thickness by 2 μm-4 μm. The grinding is performed 3 times with a current of 1.8 A, a grinding scar width of 5 mm ± 2 mm, and a brushing time of 2 seconds. The second micro-etching is to micro-etch the cover hole area to reduce copper, and the copper reduction thickness is 10μm-20μm; The third grinding is to grind the resin protruding after the second micro-etching flat, and the grinding is performed once with a current of 1.8A, a grinding scar width of 5mm±2mm, and a brushing time of 2 seconds.

4. The HDI circuit board manufacturing method according to claim 2 or 3, characterized in that: The blind hole drilling specifically includes: Laser blind vias, laser-drilling blind vias in the PCB multilayer board; The first plasma debonding removes excess resin in the blind hole.

5. The method for manufacturing an HDI circuit board according to claim 4, characterized in that: After the second copper reduction and before the third copper production, the method further comprises: Drilling a through hole for the second time to make a second through hole on the PCB multilayer board; The second plasma debonding is performed to remove excess resin in the second through hole.

6. The method for manufacturing an HDI circuit board according to claim 1, characterized in that: The pore-filling solution is composed of 9%-11% H 2 SO 4 , 5.75%-6.25% CU2+, 1.125%-1.575% leveling agent, 1.125%-1.575% brightener, and 50-70PPM CL-.

7. The method for manufacturing an HDI circuit board according to claim 1, characterized in that: The non-hole-filling solution is composed of 22.5%-27% H 2 SO 4 , 3.375%-4.15% CU2+, 0.85%-1.15% leveling agent, 0.055%-0.105% brightener, 0.75-1.25 leveling agent, and 50-70PPM CL-.

8. The method for manufacturing an HDI circuit board according to claim 1, characterized in that: The second copper making and the third copper making pulse electroplating include 6 stages, specifically including: The first stage, accounting for 15% of the entire pulse plating cycle, uses 100% positive current for pulse plating; The second stage, which accounts for 30% of the entire pulse plating cycle, uses a positive and negative current ratio of 1:3 and a positive and negative current time ratio of 20:1; The third stage, which accounts for 25% of the entire pulse plating cycle, uses a positive and negative current ratio of 1:3 and a positive and negative current time ratio of 18:9; The fourth stage, which accounts for 10% of the entire pulse plating cycle, uses a positive and negative current ratio of 1:2 and a positive and negative current time ratio of 16:8; The fifth stage, which accounts for 15% of the entire pulse plating cycle, uses a positive and negative current ratio of 1:2 and a positive and negative current time ratio of 14:7; The sixth stage, accounting for 15% of the entire pulse plating cycle, uses 100% positive current for pulse plating.

9. A HDI circuit board manufacturing device, characterized in that: The device is used to execute the HDI circuit board manufacturing method according to any one of claims 1 to 8 to manufacture a printed circuit board.

10. A printed circuit board, characterized in that: The printed circuit board is manufactured by executing an HDI circuit board manufacturing method as described in any one of claims 1 to 8 using the HDI circuit board manufacturing device as described in claim 9.

Images