A method for manufacturing a high-density circuit board with double surface treatment on the same pad

Abstract

The present invention discloses a method for manufacturing a high-density circuit board with double surface treatment on the same pad, wherein an inner core board with an inner layer circuit is manufactured, and after intermediate processing, a multilayer board is formed, and a surface circuit is manufactured on the multilayer board, including manufacturing a pad pattern, wherein the pad pattern includes a first area and a second area, and then a solder resist layer is manufactured, and the entire board is formed into a surface circuit board; a dry film pattern is manufactured on the surface circuit board, and a window of the dry film pattern corresponds to the first area, and then electroplating is performed, and the entire board is formed into an electroplated board; the dry film pattern is removed, and the second area is subjected to OSP surface treatment, and after post-processing, a circuit board is formed; the same pad pattern is subjected to different surface treatments in different areas by design, and an effective manufacturing method is formed, thereby solving the problems of a large occupied area caused by a separate pad structure with separately designed support pads and contact pads, and high processing cost and high environmental pressure caused by the use of electroplating means in batch processing.

Description

Technical Field

[0001] The present invention relates to the field of printed circuit board manufacturing, in particular to a method for manufacturing a high-density circuit board with double-surface treatment on the same pad. Background Art

[0002] Some precision control devices use high-density circuit boards. In order to achieve a dense soldering effect on the surface of the circuit board capable of soldering multiple components, it is usually necessary to solder contact devices on the surface of the circuit board.

[0003] Traditional technology for manufacturing this type of circuit board usually adopts a separate pad structure with separately designed support pads and contact pads. That is, the support pads are used for welding to form a stable base, while the contact pads correspond to the contact end applications. However, the separate pad structure will undoubtedly occupy more surface area of ​​the circuit board, which conflicts with the current trend of miniaturization and integration of electronic equipment.

[0004] The above defects are further improved by designing the support pad and the contact pad on the same pad, forming a method of welding in one area and contacting in another area, and then performing electro-gold surface treatment on the entire pad.

[0005] However, for batch production, the electroplated gold area of ​​this type of pad is relatively large. Although the electroplated gold surface treatment effect is better, the electroplated gold material (mainly gold salt solution) is relatively expensive, so the cost of electroplating is much higher than other surface treatments, and the electroplating process is more polluting. Therefore, from the perspective of processing cost and sewage treatment, the production method of electroplating the entire pad with electroplated gold surface treatment and large-scale electroplating gold processing will generate greater costs and environmental pressures.

[0006] Therefore, in order to solve the above-mentioned problems, it is necessary to provide a method for manufacturing a high-density circuit board with double surface treatment on the same pad. Summary of the Invention

[0007] The present invention aims to solve the problems of high cost and high pollution in the prior art of mass-producing a design in which both support pads and contact pads are distributed on a single pad surface, using electroplating gold surface treatment. A method for manufacturing a high-density circuit board with double-surface treatment of the same pad is proposed. The circuit board is manufactured according to a design pattern, the design pattern including a pad pattern located on the surface of the circuit board. The manufacturing method comprises the following steps:

[0008] S10: forming an inner core board with an inner layer circuit, forming a multilayer board after intermediate processing, and forming a surface circuit on the multilayer board, including forming the pad pattern, the pad pattern including a first area and a second area, and then forming a solder mask layer, and the entire board is formed into a surface circuit board;

[0009] S20: forming a dry film pattern on the surface circuit board, wherein the window of the dry film pattern corresponds to the first area, and then performing electroplating to form an electroplated plate on the entire board;

[0010] S30: removing the dry film pattern, performing OSP surface treatment on the second area, and performing post-processing to form the circuit board.

[0011] Furthermore, before making the surface circuit, blind holes are made on the multilayer board to connect the inner layer circuit and the pad pattern; the circuit board includes an effective area and an invalid area, and the invalid area is distributed with conductive copper foil, and conductive holes are made within the range of the conductive copper foil, and the conductive holes are connected to the inner layer circuit.

[0012] Furthermore, the window size of the dry film pattern is unilaterally larger than the first area size.

[0013] Furthermore, the window opening of the dry film pattern also includes a chuck clamping position during electrometallurgical processing.

[0014] Furthermore, before the OSP surface treatment, micro-etching treatment is performed.

[0015] Furthermore, the inner layer circuits and the surface circuits are staggered in distribution.

[0016] Furthermore, after the electrometallurgical processing and before the OSP surface treatment, the inner layer circuit is cut off.

[0017] Furthermore, the post-processing includes cutting off the inner layer circuit.

[0018] Furthermore, the manufacturing method for cutting off the inner layer circuit is: manufacturing a depth-controlled hole corresponding to the inner layer circuit, and the depth of the depth-controlled hole is from the surface of the circuit board to the inner layer circuit.

[0019] Furthermore, the method for cutting off the inner layer circuit is: making a through hole corresponding to the inner layer circuit.

[0020] The beneficial effects of the technical solution of the present invention include:

[0021] (1) By designing the same pad pattern for zoned differentiated surface treatment and forming an effective manufacturing method, the problems of the separate pad structure in which the support pad and the contact pad are designed separately, resulting in a large occupied area, and the existing technology of using the electroplating gold surface treatment method for the same pad in batch processing, resulting in high cost and severe environmental pollution, are solved;

[0022] (2) By conducting multiple sets of experiments with controlled variables, the high density and smooth surface characteristics of the electroplated gold layer are utilized, and the inability of the OSP layer to form effective adhesion on its surface is utilized to ensure that the electroplated gold layer and the OSP layer can form differentiated surfaces on the same pad without affecting each other, thereby enhancing the reliability of the pad pattern and the welding quality;

[0023] (3) Furthermore, by pre-enlarging the window of the dry film pattern, a larger allowable error can be provided for the production of the dry film pattern. At the same time, it is equivalent to pre-enlarging the area of ​​the electroplating gold layer in the first area, covering the area that originally needs to be treated with OSP to a certain extent, and reducing the risk of copper surface oxidation caused by OSP failure;

[0024] (4) By designing and manufacturing the inner layer circuit to form the electro-gold lead, and connecting the inner layer circuit to the pad pattern through the blind hole, combined with the subsequent process of cutting the inner layer circuit, the inner layer circuit and the surface circuit are staggered and distributed, providing an effective processing basis for the electro-gold processing of the first area of ​​the pad;

[0025] (5) The entire technical solution achieves the effect of differentiated surface treatment of the same pad through the synergistic effect of the above-mentioned pad area treatment and process processing, forming an overall correlation and synergy effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0027] Figure 1 Schematic diagram of the process flow of an embodiment of the present invention;

[0028] Figure 2 A schematic plan view of an inner core plate according to an embodiment of the present invention;

[0029] Figure 3 for Figure 2 AA cross-section diagram;

[0030] Figure 4 Schematic diagram of a planar surface of an electroplated gold plate according to an embodiment of the present invention;

[0031] Figure 5 for Figure 4 BB cross-section diagram;

[0032] Figure 6 for Figure 5 Schematic diagram of a local magnified area of ​​FD;

[0033] Figure 7 Schematic diagram of a plan view of an OSP board according to an embodiment of the present invention;

[0034] Figure 8 for Figure 7 Schematic diagram of CC cross section;

[0035] Figure 9 Schematic diagram of a plan view of an OSP board with controlled deep holes according to an embodiment of the present invention;

[0036] Figure 10 for Figure 9 DD cross-sectional diagram;

[0037] Figure 11 A schematic plan view of the depth control hole design data according to an embodiment of the present invention;

[0038] Figure 12 A schematic plan view of a circuit board according to an embodiment of the present invention;

[0039] Figure 13 A schematic plan view of a circuit board pad graphic design document according to an embodiment of the present invention;

[0040] Figure 14 A metallographic microscope observation diagram of a pad pattern of a circuit board according to an embodiment of the present invention;

[0041] Figure 15 This is a metallographic microscope observation image of another circuit board pad pattern according to an embodiment of the present invention.

[0042] Explanation of the accompanying numbers: 100, effective area; 200, invalid area; 300, conductive copper foil; 400, conductive hole; 500, chuck clamping position; 10, inner core board; 1010, inner layer circuit; 1020, blind hole; 1030, pad pattern; 1040, upper surface circuit; 1050, lower surface circuit; 20, electroplated gold board; 2010, dry film pattern; 2020, electroplated gold layer; 2030, upper surface solder mask; 2040, lower surface solder mask; FD, local enlarged area; SC, design size; YC, pre-large size; 30, OSP board; 3010, OSP layer; 3020, controlled depth hole; 40, circuit board.

[0043] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. DETAILED DESCRIPTION

[0044] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0045] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, inside, outside, etc.) are only used to explain the relative position relationship and movement status of the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0046] In addition, the terms "first," "second," and so on, used in this disclosure are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referenced. Thus, a feature specified as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of this disclosure, "plurality" means at least two, such as two or three, unless otherwise specifically defined.

[0047] In addition, the technical solutions between the various embodiments of the present invention can be combined with each other, but it must be based on the fact that ordinary technicians in this field can implement it. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0048] See also Figure 1 , Figure 1 Schematic diagram of the process flow of an embodiment of the present invention.

[0049] The manufacturing process of the embodiment of the present invention includes using Figure 1 The following will implement the various steps in the process Figure 1 Each step in the process is further explained step by step.

[0050] Please see first Figure 2 、 Figure 3 , Figure 2 A schematic plan view of an inner core plate according to an embodiment of the present invention; Figure 3 for Figure 2 AA cross-section diagram.

[0051] The high-density circuit board with double-surface treatment of the same pads in this embodiment is manufactured according to a design pattern, which includes a pad pattern 1030 located on the surface of the circuit board.

[0052] S10: An inner core board 10 having an inner layer circuit 1010 is produced, and after intermediate processing, a multilayer board is formed. A surface circuit is produced on the multilayer board, including producing a pad pattern 1030, the pad pattern 1030 including a first area and a second area, and then a solder mask layer is produced, and the entire board is formed into a surface circuit board.

[0053] Furthermore, before making the surface circuit, a blind hole 1020 is made in the multilayer board to connect the inner layer circuit 1010 and the pad pattern 1030; the circuit board includes an effective area 100 and an ineffective area 200, and the ineffective area 200 is distributed with a conductive copper foil 300, and a conductive hole 400 is made within the conductive copper foil 300, and the conductive hole 400 is connected to the inner layer circuit 1010.

[0054] By first making the inner core board 10 and then making the blind hole 1020, the position of the blind hole 1020 corresponds to the pad pattern 1030, forming the effect of connecting the pad pattern 1030 and the inner layer circuit 1010, providing a processing basis for the subsequent electrometallurgical processing.

[0055] Since the pad pattern 1030 in this embodiment requires two surface treatments, the high-density circuit design of the circuit board results in its surface circuits (including the upper surface circuit 1040 and the lower surface circuit 1050) being relatively dense, and it is difficult to set the gold wire on the surface circuits.

[0056] Therefore, in order to guide the gold lead from the inner layer circuit 1010 to the position of the pad pattern 1030 without affecting the layout of the surface circuit, this embodiment is designed to connect through the blind hole 1020, which effectively avoids arranging the gold lead directly in the surface circuit, resulting in smaller circuit spacing and easily causing potential problems such as signal interference.

[0057] Optionally, the blind via 1020 can be connected to the inner layer circuit 1010 of the next outer layer, or can be connected to the inner layer circuit 1010 of other layers according to the depth distribution condition. Therefore, the blind via 1020 connected to the inner layer circuit 1010 has a greater space condition for selecting circuit distribution.

[0058] Optionally, the manufacturing process of the blind hole 1020 is as follows: an inner core board 10 with an inner circuit 1010 is manufactured, layout and pressing are performed according to the stacking structure of the circuit board, and then laser drilling is performed, and then the blind hole 1020 is filled and electroplated to form the blind hole 1020, and then the surface circuit pattern is manufactured.

[0059] Optionally, the blind hole 1020 is made by laser drilling or mechanical drilling.

[0060] See also Figure 4 、 Figure 5 and Figure 6 , Figure 4Schematic diagram of a planar surface of an electroplated gold plate according to an embodiment of the present invention; Figure 5 for Figure 4 BB cross-section diagram; Figure 6 for Figure 5 Schematic diagram of a local magnified area of ​​FD.

[0061] First, the surface circuitry of the inner core board 10 is fabricated, including the design of the pad pattern 1030. Specifically, the pad pattern 1030 is subdivided into two distinct first and second regions, corresponding to the soldering area (where the gold layer 2020 is formed in a later process) and the contact area (where the OSP layer 3010 is formed in a later process), respectively. This provides the necessary processing foundation for subsequent processes to apply different surface treatment processes to different partitions. The solder mask layer (including the upper surface solder mask layer 2030 and the lower surface solder mask layer 2040) is then fabricated to protect the circuit board from the external environment, such as preventing oxidation, avoiding short circuits, and improving electrical insulation performance.

[0062] Furthermore, the inner layer circuits 1010 and the surface circuits are staggered in distribution.

[0063] The inner layer circuit 1010 and the surface circuit are staggered in distribution in the plane direction of the circuit board 40. Since the inner layer circuit 1010 is mainly used as an auxiliary circuit to provide a conductive lead when making the pad pattern 1030, the inner layer circuit 1010 can be non-straight, avoiding the routing design of the surface circuit, facilitating the subsequent process of cutting the inner layer circuit 1010, and effectively avoiding the risk of the surface circuit being affected and damaged by drilling or drilling operations.

[0064] See also Figure 7 and Figure 8 , Figure 7 Schematic diagram of a plan view of an OSP board according to an embodiment of the present invention; Figure 8 for Figure 7 Schematic diagram of CC cross section.

[0065] S20: a dry film pattern 2010 is formed on the surface circuit board. The window of the dry film pattern 2010 corresponds to the first area. Then, electroplating is performed to form an electroplating layer 2020 on the surface of the first area. The entire board is formed into an electroplating plate 20.

[0066] Furthermore, the window of the dry film pattern 2010 also includes a chuck clamping position 500 during electrometallurgical processing.

[0067] Furthermore, the window size of the dry film pattern 2010 is unilaterally larger than the size of the first region.

[0068] Since there are certain errors in the exposure, development, and etching processing steps of manufacturing the dry film pattern 2010, by pre-enlarging the design size SC of the window of the dry film pattern 2010 to form a pre-enlarged size YC, a certain error tolerance range can be provided for these process steps to ensure that the final circuit pattern meets the design requirements.

[0069] Furthermore, OSP treatment is a surface treatment method commonly used to prevent copper oxidation, but its shelf life is relatively short, and it may ablate or fall off during subsequent storage. Therefore, by enlarging the first area (i.e., the electroplated gold layer 2020 area), the area that originally required OSP surface treatment can be covered to a certain extent, reducing the risk of copper surface oxidation due to failure of the OSP layer 3010. If the area of ​​the OSP layer 3010 is too large, it may be exposed for various reasons during subsequent processing, resulting in oxidation of the copper surface of the circuit. Pre-enlarging the first area can effectively avoid this situation, and even slight deviations in the manufacturing process will not affect the quality and reliability of the final product.

[0070] Furthermore, since a good metallized surface can provide more reliable welding points, and compared with OSP treatment, electroplating provides better welding performance and durability, therefore, appropriately expanding the first area helps to improve welding quality and reduce the risk of cold solder joints and desoldering.

[0071] Optionally, the window size of the dry film pattern 2010 is larger than the first region size by 20 μm to 100 μm on one side.

[0072] See also Figures 9 to 15 , Figure 9 Schematic diagram of a plan view of an OSP board with controlled deep holes according to an embodiment of the present invention; Figure 10 for Figure 9 DD cross-sectional diagram; Figure 11 A schematic plan view of the depth control hole design data according to an embodiment of the present invention; Figure 12 A schematic plan view of a circuit board according to an embodiment of the present invention; Figure 13 A schematic plan view of a circuit board pad graphic design document according to an embodiment of the present invention; Figure 14 A metallographic microscope observation diagram of a pad pattern of a circuit board according to an embodiment of the present invention; Figure 15 This is a metallographic microscope observation image of another circuit board pad pattern according to an embodiment of the present invention.

[0073] S30 : removing the dry film pattern 2010 and performing OSP surface treatment on the second area to form an OSP board 30 , which is then processed through a post-process to form a circuit board 40 .

[0074] Furthermore, the post-processing includes cutting off the inner layer circuit 1010 to prevent the inner layer circuit 1010 from being connected to the surface circuit, thereby preventing problems such as short circuits.

[0075] Preferably, the inner layer circuit 1010 is cut off after electrometallurgy processing and before OSP surface treatment. Since the OSP layer 3010 is relatively fragile, by adjusting the processing procedure, the mechanical processing of cutting the inner layer circuit 1010 is adjusted to before OSP surface treatment, which can effectively avoid problems such as wear or scratches on the OSP layer 3010.

[0076] Optionally, the manufacturing method for cutting the inner layer circuit 1010 is: manufacturing a depth-controlled hole 3020 corresponding to the inner layer circuit 1010 , wherein the depth of the depth-controlled hole 3020 is from the surface of the circuit board to the inner layer circuit 1010 .

[0077] Optionally, the method for cutting the inner layer circuit 1010 is: making a through hole corresponding to the inner layer circuit 1010, which is suitable for a thin circuit board and where there is no circuit distribution on the upper and lower surfaces of the circuit board 40 corresponding to the position where the through hole is made.

[0078] Optionally, before OSP surface treatment, micro-etching is performed to avoid damaging the electroplating gold layer 2020 and the solder mask layer (including the upper surface solder mask layer 2030 and the lower surface solder mask layer 2040), while providing a clean surface condition with a certain uniform roughness for the production of OSP surface treatment. Furthermore, the micro-etching copper thickness is controlled to be 3μm to 10μm.

[0079] The second area is then subjected to OSP surface treatment to form an organic antioxidant film on the copper surface. Its main function is to cover the copper surface and prevent it from oxidation during storage and transportation.

[0080] Among them, the electroplated gold layer 2020 formed in the first area is the contact pad, and the OSP layer 3010 formed in the second area is the supporting pad. When the contact component needs to be set on the surface of the circuit board 40, a steel mesh can be used to print solder paste on the area of ​​the OSP layer 3010, and the contact component can be positioned. Through the reflow soldering method, the solder feet of the contact component are soldered to the second area, and the first area corresponds to the contact point of the contact component.

[0081] It is worth noting that before preparing to solder components, flux is usually applied to the surface of the circuit board. The solder resist generally contains components such as organic acids, which can quickly dissolve the OSP layer 3010. Therefore, during the actual soldering process, this layer of OSP film will be quickly melted, exposing the copper surface underneath for easy soldering operations.

[0082] In other words, OSP surface treatment is only a temporary protective measure from the time the finished circuit board is shipped to the start of component soldering. Unlike some other surface treatments that may remain on the circuit board after soldering, the OSP layer 3010 will not remain in the final product. It is only an auxiliary surface treatment for a process before the finished circuit board is shipped to the time the components are soldered on the circuit board, so that its contact points can maintain the best soldering state and can be smoothly removed during soldering without any negative impact on the soldering quality. This not only ensures the efficiency of the production process, but also ensures the quality and reliability of the final electronic product.

[0083] In addition, the production process of OSP surface treatment is simple and efficient. Its processing efficiency in the same unit time is several times that of electroplating, so it can significantly improve production efficiency and is particularly suitable for mass production. In addition, the materials used in OSP surface treatment are relatively environmentally friendly, and the wastewater generated is more convenient and efficient to treat, thereby reducing the pressure on the environment.

[0084] It is worth noting that this embodiment designs and implements a series of multiple groups of experiments conducted by controlling variables. These experiments are intended to verify that two different surface treatments can be effectively formed on the same pad graphic 1030, while ensuring that there is no mutual influence or interference between the two, that is, there will be no mutual influence or interference during the processing process and subsequent welding and use.

[0085] After analysis, testing and verification, the double surface treatment combination of "electro-gold combined with OSP" is found to be the best combination, and the electro-gold layer 2020 and the OSP layer 3010 on the same pad are compatible and independent.

[0086] It is worth noting that the experimental verification process is to first select the following combinations: electroplating combined with immersion gold, electroplating combined with immersion tin, electroplating combined with immersion silver, and electroplating combined with spray tin to produce the same pad pattern 1030 on both surfaces. However, these combinations require secondary production of the dry film pattern 2010 to protect and expose different areas of the pad respectively, and produce different surface treatments, which increases the complexity and cost of the process. At the same time, due to the large processing error of the dry film pattern 2010, the surface treatment may not fully meet the design requirements, affecting product quality. Most importantly, the interaction between the two metal surface treatments may cause mutually affecting chemical reactions or surface defects, making it difficult to effectively apply in batch processing.

[0087] Then choose: immersion gold combined with OSP, immersion silver combined with OSP, immersion tin combined with OSP, and spray tin combined with OSP to produce the same pad pattern 1030 on both surfaces. Since the immersion gold layer formed by chemical deposition has a low density and low hardness, the surface has a certain roughness, which may make it difficult for the OSP layer 3010 to adhere evenly, resulting in contamination or residue problems during later use, affecting the quality and reliability of the final product. Especially during multiple soldering processes, the consumption rate of the OSP layer 3010 is accelerated, which may increase the exposure risk of the underlying metal.

[0088] Please refer again Figure 14 and Figure 15 After a lot of verification, it was found that the combination of electroplating and OSP is the optimal combination for double surface treatment of the same pad. Since the electroplating layer 2020 formed by the electroplating surface treatment has a high density and smooth surface quality, it has better durability and reliability, and the OSP layer 3010 can selectively adhere to the surface of the copper layer without adhering to the electroplating layer 2020 or the solder mask layer (including the upper surface solder mask layer 2030 and the lower surface solder mask layer 2040). This means that it can provide temporary protection for the target copper layer without affecting the electroplating area, prevent oxidation, and ensure reliability in the subsequent welding process.

[0089] The above description is only a preferred embodiment of the present invention and does not limit the patent scope of the present invention. All equivalent structural transformations made by using the contents of the present invention description and drawings under the inventive concept of the present invention, or direct / indirect application in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A method for manufacturing a high-density circuit board with double-surface treatment of the same pad, wherein the circuit board is manufactured according to a design pattern, wherein the design pattern includes a pad pattern located on the surface of the circuit board, characterized in that: The production method comprises the following steps: S10: forming an inner core board with an inner layer circuit, forming a multilayer board after intermediate processing, and forming a surface circuit on the multilayer board, including forming the pad pattern, the pad pattern including a first area and a second area, and then forming a solder mask layer, and the entire board is formed into a surface circuit board; Before fabricating the surface circuit, a blind hole is fabricated on the multilayer board to connect the inner layer circuit and the pad pattern; the circuit board comprises an effective area and an ineffective area, the ineffective area is provided with conductive copper foil, and a conductive hole is fabricated within the conductive copper foil, the conductive hole being connected to the inner layer circuit; S20: forming a dry film pattern on the surface circuit board, wherein the window of the dry film pattern corresponds to the first area, and then performing electroplating to form an electroplated plate on the entire board; S30: removing the dry film pattern, performing OSP surface treatment on the second area, and performing post-processing to form the circuit board.

2. The method for manufacturing a high-density circuit board with double-surface treatment of the same pad as claimed in claim 1, characterized in that: The window size of the dry film pattern is larger than the first area size on one side.

3. The method for manufacturing a high-density circuit board with double-surface treatment of the same pad as claimed in claim 1, characterized in that: The windowing of the dry film pattern also includes a chuck clamping position during electrometallurgical processing.

4. The method for manufacturing a high-density circuit board with double-surface treatment of the same pad as claimed in claim 1, characterized in that: Before the OSP surface treatment, micro-etching treatment is performed.

5. The method for manufacturing a high-density circuit board with double-surface treatment of the same pad as claimed in claim 1, characterized in that: The inner layer circuits and the surface circuits are staggered in distribution.

6. The method for manufacturing a high-density circuit board with double-surface treatment of the same pad as claimed in claim 1, characterized in that: After the electrometallurgical processing and before the OSP surface treatment, the inner layer circuit is cut off.

7. The method for manufacturing a high-density circuit board with double-surface treatment of the same pad as claimed in claim 1, characterized in that: The post-processing includes cutting the inner layer circuit.

8. A method for manufacturing a high-density circuit board with double-surface treatment of the same pad as claimed in claim 6 or 7, characterized in that: The manufacturing method for cutting off the inner layer circuit is: manufacturing a depth-controlled hole corresponding to the inner layer circuit, wherein the depth of the depth-controlled hole is from the surface of the circuit board to the inner layer circuit.

9. A method for manufacturing a high-density circuit board with double-surface treatment of the same pad as claimed in claim 6 or 7, characterized in that: The manufacturing method of cutting off the inner layer circuit is: making a through hole corresponding to the inner layer circuit.

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