Manufacturing method of large-aperture and high-board-thickness plug-in blind hole and PCB (Printed Circuit Board)

Abstract

The invention discloses a large-aperture and high-board-thickness plug-in blind hole manufacturing method and a PCB, and the manufacturing method comprises the steps: providing a first optical core board and a substrate with a through hole A, enabling the first optical core board to be laminated and fixed on one side of the substrate, machining a through hole B in the first optical core board, and enabling the through hole B and the through hole A to be aligned and communicated to form a blind hole base hole; plating a conducting copper layer on the inner wall of the base hole of the blind hole; sealing one port, back on to the first optical core plate, of the blind hole base hole by using a protective film, and filling the blind hole base hole with resin; removing the protective film after the resin is cured or semi-cured, and laminating and fixing a second optical core plate on one side, back to the first optical core plate, of the substrate; and cutting the resin for multiple times until the conductive copper layer arranged on the inner wall of the blind hole base hole is completely exposed, and cutting the conductive copper layer into a set thickness to obtain the plug-in blind hole. The manufacturing method is reasonable, simple and easy to operate and implement, and the obtained plug-in blind hole has the advantages of being high in size precision, good in structural stability, good in conduction performance and the like.

Description

Technical Field

[0001] This invention relates to the field of circuit board technology, and in particular to a method for manufacturing large-diameter, thick-board-thickness blind vias and a PCB board thereof. Background Technology

[0002] In PCB board structure, blind vias are mainly used to connect the surface layer and the inner layer of the circuit board. The conventional manufacturing method for blind vias is as follows: drill through holes, plate copper on the hole walls to achieve conductivity, plug the hole with resin (to prevent the prepreg from melting and flowing into the hole during subsequent lamination processes), and press-fit one end of the hole to seal it.

[0003] With the rapid development of PCB products, through-hole blind vias with larger apertures (e.g., 2mm and above) and greater board thickness (e.g., 5mm and above) have become the mainstream blind via structure for electronic products. However, when using conventional blind via manufacturing processes to produce through-hole blind vias with these large aperture and high board thickness characteristics, the following problems are likely to occur: 1) Due to the high thickness of the board for the plug-in blind hole, it is necessary to use more than a dozen prepreg sheets for lamination during the manufacturing process. This is not only cumbersome and labor-intensive, but also results in poor alignment accuracy between the through holes during drilling due to the large number of prepreg sheets, thus causing poor dimensional accuracy of the plug-in blind hole.

[0004] 2) Due to the large diameter and thick plate of the blind holes in the plug-in, more resin is required when filling the holes with resin. This can easily lead to abnormal phenomena such as poor filling and resin depression, which increases the difficulty of product processing.

[0005] Moreover, since the resin plugging process is difficult to rework, if an abnormality is found during product testing, the entire batch of products will be unusable, resulting in significant production waste.

[0006] 3) To facilitate the insertion of electrical components, the blind vias must be free of resin. This means the copper layer on the inner wall of the blind via must be exposed to allow for connection between the blind via and the electrical components inside. Therefore, after fabricating the blind via prototype using conventional blind via manufacturing processes, a back-drilling process is required to remove the resin from the prototype. However, since the drill bit's precision tolerance is typically 1 mil (25.4 μm), while the copper thickness control tolerance on the hole wall can be precise to the nanometer level, back-drilling may potentially cut away essential hole wall copper, causing the blind via to lose conductivity and resulting in an open circuit.

[0007] In view of this, the present invention is hereby proposed. Summary of the Invention

[0008] To overcome the above-mentioned defects, the present invention provides a method for manufacturing large-diameter, thick-board-thickness plug-in blind vias and a PCB board. The manufacturing method is reasonable, simple, and easy to operate and implement. The resulting plug-in blind vias have advantages such as high dimensional accuracy, good structural stability, and good conductivity, which well meet market demands.

[0009] The technical solution adopted by this invention to solve its technical problem is: a method for manufacturing large-diameter, high-thickness blind holes for inserts, comprising: A first optical core plate and a substrate with a through hole A are provided. The first optical core plate is laminated and fixed on one side of the substrate. A through hole B is processed on the first optical core plate. The through hole B and the through hole A are arranged along the same center line and are aligned and connected to form a blind hole base hole. A conductive copper layer of predetermined thickness is plated on the inner wall of the blind hole base hole; A protective film with high temperature resistance and removability is used to seal one end of the blind hole base hole facing away from the first optical core plate, and then resin is filled into the blind hole base hole through a resin plugging process. After the resin has cured or partially cured, the protective film is removed, and a second optical core plate is laminated and fixed on the side of the substrate facing away from the first optical core plate. The resin is cut multiple times using a controlled depth milling process until the conductive copper layer on the inner wall of the blind hole base hole is completely exposed. At the same time, the conductive copper layer is also cut to a set thickness, thus creating a plug-in blind hole with a portion of the second optical core board as the hole bottom.

[0010] As a further improvement of the present invention, both the first optical core board and the second optical core board are rigid optical core boards with the surface copper layer removed.

[0011] As a further improvement of the present invention, the rigid optical core plate is made of epoxy resin.

[0012] As a further improvement of the present invention, a alignment target is first drilled on the substrate, and then the through hole A is drilled on the substrate based on the alignment target. In addition, the through hole B is drilled on the first optical core plate based on the alignment target, so as to ensure that the through hole B and the through hole A are arranged on the same center line.

[0013] As a further improvement of the present invention, while depositing the conductive copper layer on the inner wall of the blind via through copper plating and electroplating processes, copper plating layers are also deposited on both sides opposite to the substrate of the first optical core board. The two copper plating layers are smoothly transitioned and connected to the two ends of the conductive copper layer, and the copper thickness of the conductive copper layer is... With respect to the copper thickness of the copper plating layer They respectively satisfy the following relations: ; In the formula, The standard thickness of the preset conductive copper layer, This is the standard inner diameter of the preset blind hole for the plug-in.

[0014] As a further improvement of the present invention, the protective film is a high-temperature resistant dry film, and is applied to one end of the blind hole base hole facing away from the first optical core plate by a vacuum film application process; In addition, the protective film is separated from one end of the blind hole base hole by mechanical peeling.

[0015] As a further improvement of the present invention, the axial depth of the blind hole base hole is not less than 5 mm, and correspondingly, the resin is filled into the blind hole base hole by a segmented screen printing process.

[0016] As a further improvement of the present invention, the resin is subjected to two cutting processes, wherein the diameter of the drill bit used in the first cutting process is... The diameter of the drill bit used in the second cutting. They respectively satisfy the following relations: ; In the formula, This is the standard inner diameter of the preset blind hole for the plug-in.

[0017] The present invention also provides a PCB board having blind vias for insertion and mating with external electrical components. The blind vias are manufactured using the method for manufacturing large-diameter, high-thickness blind vias as described in the present invention.

[0018] The beneficial effects of this invention are as follows: Compared with the prior art, this application improves and innovates the manufacturing method of large-diameter, high-thickness plug-in blind holes. ① In the first lamination operation, this application uses a rigid core plate to replace several prepreg sheets in the prior art. This not only simplifies the lamination process and improves lamination efficiency, but also ensures that the through hole B and through hole A have very high alignment / alignment accuracy after the lamination operation and subsequent drilling operation, providing good technical support for the high-precision dimensions of the plug-in blind holes. ② Before the resin plugging operation, this application uses a protective film with high temperature resistance and removable properties to seal one end of the blind hole base hole facing away from the first core plate. This effectively ensures that the resin will not flow out from the closed end of the blind hole base hole during the resin plugging operation, thereby achieving full filling of the blind hole base hole and effectively ensuring the lamination quality of the subsequent process. ③ The segmented printing method adopted in this application avoids voids in the holes caused by poor resin flow and effectively prevents resin cracking due to differences in the thermal expansion coefficients of copper foil, thus meeting the process requirements for uniform resin filling. Furthermore, the pre-baking operation between adjacent printing operations in this embodiment allows the resin filled in the previous printing operation to initially solidify and expel some volatiles, reducing defects such as air bubbles generated during resin filling in subsequent printing operations, further improving the density of the resin filling and ensuring the lamination quality of subsequent processes. ④ This application utilizes controlled-depth milling technology to perform multiple cuts on the resin, effectively improving the processing quality of the resulting blind holes and ensuring the conductivity of the blind holes. ⑤ The method for manufacturing large-diameter, high-thickness blind holes provided in this application is reasonable, has a simple process flow, and is easy to operate and implement. Attached Figure Description

[0019] Figure 1 This is a flowchart of the method for manufacturing large-diameter, thick-plate-thickness blind holes in Embodiment 1 of the present invention; Figure 2 This is a schematic cross-sectional view of the substrate described in Example 1; Figure 3 This is a schematic cross-sectional view of the structure after the first optical core plate and the substrate are laminated and bonded together in Example 1. Figure 4 This is a schematic cross-sectional view of the intermediate plate A obtained in Example 1; Figure 5 This is a schematic cross-sectional view of the structure after the protective film is applied to one side of the resulting intermediate plate A in Example 1; Figure 6 This is a schematic cross-sectional view of the blind hole base hole after resin is filled in Example 1; Figure 7 This is a schematic cross-sectional view of the intermediate plate B obtained in Example 1; Figure 8 This is a schematic cross-sectional view of the blind hole in the plug-in obtained in Example 1.

[0020] Referring to the accompanying drawings, the following explanations are provided: 1. First optical core board; 10. Through hole B; 2. Substrate; 20. Through hole A; 21. Insulating intermediate layer; 22. Copper foil layer; 3. Blind hole base hole; 4. Conductive copper layer; 5. Protective film; 6. Resin; 7. Second optical core board; 8. Plug-in blind hole; 9. Copper plating layer. Detailed Implementation

[0021] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0022] Example 1

[0023] Please see the appendix Figure 1 To be continued Figure 8 As shown, this embodiment 1 provides a method for manufacturing blind holes with large diameter and high plate thickness, including the following manufacturing steps: S1: A first optical core plate 1 and a substrate 2 with a through hole A20 are provided. The first optical core plate 1 is laminated and fixed to one side of the substrate 2, and a through hole B10 is processed on the first optical core plate 1. The through hole B10 and the through hole A20 are arranged along the same center line and aligned and connected to form a blind hole base hole 3. For details, please refer to the appendix. Figure 2 and attached Figure 3 As shown.

[0024] Specifically, regarding the first optical core board 1, this embodiment preferably uses a rigid optical core board with the surface copper layer removed. Furthermore, the material of the rigid optical core board can be, but is not limited to, epoxy resin; understandably, epoxy resin exhibits rigidity after high-temperature curing. Additionally, the thickness of the first optical core board 1 is determined according to the design requirements of the axial depth (or "thickness") of the blind hole in the plug-in section described in this application. This application does not impose any limitations; for example, the thickness of the first optical core board 1 can be designed to be approximately 1.6 mm.

[0025] Regarding the substrate 2, its implementation structure is determined according to the design requirements of the PCB product, and this application does not impose any restrictions. However, in order to clearly and thoroughly describe the method for manufacturing large-diameter, thick-board-thickness through-hole vias provided in this application, this embodiment uses a double-sided copper-clad laminate as an example for explanation and illustration.

[0026] Please continue to refer to the appendix. Figure 2As shown, the substrate 2 has the following structure: it comprises a main body and a through hole A20. The main body consists of an insulating intermediate layer 21 and two copper foil layers 22 respectively fixedly attached to opposite sides of the insulating intermediate layer 21. The through hole A20 is located on the main body and penetrates both copper foil layers 22. Further, the insulating intermediate layer 21 may be, but is not limited to, a prepreg, and the thickness of both the insulating intermediate layer 21 and the copper foil layers 22 is determined according to the design requirements of the axial depth of the plug-in blind hole; this application does not impose any restrictions. The inner diameter of the through hole A20 is determined according to the design requirements of the standard inner diameter of the plug-in blind hole; this application also does not impose any restrictions, for example, the inner diameter of the through hole A20 may be designed to be 2-3 mm.

[0027] In addition, in this embodiment, the following drilling method can be used to manufacture the through hole A20: first, a alignment target is drilled on the main body of the substrate 2 using mechanical drilling or laser drilling, and then the through hole A20 is drilled on the main body of the substrate 2 based on the alignment target. It is understood that, with the help of the alignment target, the through hole A20 has high processing accuracy.

[0028] Based on the above-described structure of the first optical core board 1 and the substrate 2, this embodiment uses a lamination process to press and fix the first optical core board 1 onto a copper foil layer 22. It is understood that, compared to the prior art where a dozen or more prepreg sheets are pressed and fixed onto the substrate 2, this embodiment uses a rigid optical core board to replace the aforementioned prepreg sheets. This not only simplifies the lamination process and improves lamination efficiency, but also, due to the high structural stability of the rigid optical core board, ensures a very high alignment / alignment accuracy between the through-hole B10 and the through-hole A20 after lamination and subsequent drilling operations. This provides good technical support for the high-precision dimensions of the through-hole. Furthermore, the structural stability of the rigid optical core board significantly improves the warping problem, further enhancing the processing quality of the PCB board.

[0029] Furthermore, after completing the aforementioned lamination and pressing, in this embodiment, using the aforementioned alignment target as a reference, the through hole B10 is drilled on the first optical core plate 1 through mechanical drilling or laser drilling. It is understood that the through hole B10 and the through hole A20 are arranged along the same centerline, and they have a very high alignment accuracy; that is, the inner wall smoothness of the blind hole base hole 3 formed by aligning the through hole B10 and the through hole A20 is very high.

[0030] In addition, after the blind hole base hole 3 is formed, this embodiment also performs AOI optical inspection on the blind hole base hole 3 to ensure the processing quality of the blind hole base hole 3.

[0031] Furthermore, for ease of describing the subsequent manufacturing process, this embodiment also defines the copper foil layer 22 adjacent to the first optical core board 1 as copper foil layer A, and the remaining copper foil layer 22 as copper foil layer B.

[0032] S2: While depositing a predetermined thickness of conductive copper layer 4 on the inner wall of the blind hole base hole 3 through copper plating and electroplating processes, copper plating layers 9 are also deposited on the side of the first optical core board 1 facing away from the substrate 2 and on the side of the copper foil layer B facing away from the first optical core board 1. The two copper plating layers 9 are smoothly transitioned and connected to the two ends of the conductive copper layer 4, as shown in the appendix. Figure 4 As shown; and according to the design requirements of the plug-in blind via, the copper thickness of the conductive copper layer 4 is... With respect to the copper thickness of the copper plating layer 9 They also satisfy the following relationships respectively: ; In the formula, The standard thickness of the preset conductive copper layer, The standard inner diameter of the pre-set blind hole for the plug-in, is a coefficient.

[0033] For example: based on the production requirements of blind holes for plug-in components, when... Designed to be 23μm + 5μm When designed to be 2±0.075mm, with Taking 2.025mm as an example, and The minimum value needs to be designed to be 78.975 μm. Understandably, in the S2 processing described above, and It can be designed to be 80μm.

[0034] Additional explanation: The above-mentioned copper plating refers to depositing a thin seed layer on the inner wall of the blind hole base hole 3, the first optical core plate 1 and the copper foil layer B through a chemical copper plating process; the above-mentioned electroplating refers to electroplating a copper plating layer of a certain thickness on the obtained seed layer through a vertical electroplating process; and the obtained electroplated copper layer and the obtained seed layer together constitute the copper plating layer 9.

[0035] In addition, for the convenience of describing the subsequent process, this embodiment defines the board obtained after completing the above S2 operation as intermediate board A, the copper plating layer 9 disposed on the first optical core board 1 as copper plating layer A, and the copper plating layer 9 disposed on the copper foil layer B as copper plating layer B.

[0036] S3: Provide a protective film 5 (e.g., a high-temperature resistant dry film) with high temperature resistance and removability. Apply the protective film 5 to the copper plating layer B of the intermediate board A using a vacuum lamination process to seal one end of the blind via 3 facing away from the first optical core board 1. (See attached document.) Figure 5 As shown; then, resin 6 is filled into the blind hole base hole 3 through a resin plugging process, as shown in the attached document. Figure 6 As shown.

[0037] Understandably, since the protective film 5 is made of high-temperature resistant dry film, such as the Changxing E9420DI dry film with a temperature resistance range of up to about 200℃, the protective film 5 can effectively ensure that the resin will not flow out from the closed end of the blind hole base hole 3 during the resin plugging operation, thereby achieving full filling of the blind hole base hole 3 and effectively ensuring the lamination quality of the subsequent process.

[0038] Furthermore, since the axial depth of the blind hole base hole 3 is designed to be no less than 5mm, to ensure the filling quality of the resin 6, this embodiment preferably employs a segmented screen printing process to fill the blind hole base hole 3 with the resin 6. Specifically, the segmented screen printing process includes N alternating printing operations and N-1 pre-baking operations, where N is no less than 2 (more preferably 3 or 4). Understandably, compared to printing a thicker / larger amount of resin in one go, the segmented printing method adopted in this embodiment avoids voids in the holes caused by poor resin flow and effectively prevents the resin from cracking due to differences in the thermal expansion coefficient of the copper foil, thus meeting the process requirements for uniform resin filling. In addition, the pre-baking operation set between adjacent printing operations in this embodiment allows the resin filled in the previous printing operation to initially solidify and expel some volatiles, reducing defects such as air bubbles generated during the subsequent resin filling process, further improving the density of the resin filling and ensuring the lamination quality of the later processes.

[0039] Furthermore, the processing parameters for the above pre-baking operation can be optimized as follows: baking temperature of 115℃~125℃, pre-baking treatment of 10~15min.

[0040] Furthermore, after completing the segmented screen printing operation, the resin 6 needs to be baked and cured to ensure that the resin 6 is in a fully cured or semi-cured state. More specifically, the baking and curing parameters are preferably: a baking temperature of 120°C and a baking time of 20–40 minutes.

[0041] S4: After the resin 6 is fully cured or partially cured, the protective film 5 is removed by mechanical peeling, and at the same time, the second optical core plate 7 is laminated and fixed on the side of the substrate 2 facing away from the first optical core plate 1; see appendix. Figure 7 As shown.

[0042] The second optical core plate 7 has the same technical features as the first optical core plate 1 in terms of structure, material and thickness, so it will not be described in detail here.

[0043] In addition, for the convenience of describing the subsequent manufacturing process, this embodiment will also define the board obtained after completing the above S4 operation as intermediate board B.

[0044] S5: The resin 6 on the obtained intermediate board B is repeatedly cut using a controlled depth milling process until the conductive copper layer 4 on the inner wall of the blind hole base hole 3 is completely exposed. At the same time, the conductive copper layer 4 is also cut to a set thickness, that is, a plug-in blind hole 8 with a portion of the second optical core board 7 as the hole bottom is formed. See Appendix. Figure 8 As shown.

[0045] Specifically, according to processing requirements, this embodiment performs two cuts on the resin 6 on the obtained intermediate plate B. The diameter of the drill bit used in the first cut is... and the diameter of the drill bit used in the second cutting. They respectively satisfy the following relations: ; In the formula, This is the standard inner diameter of the preset blind hole for the plug-in.

[0046] Understandably, when When designed to be 2.025mm, the drill bit diameter and The thicknesses are 1.975mm and 2mm respectively. At this point, the remaining thickness of the conductive copper layer 4 is 25μm, meeting the design requirements for the blind via. Furthermore, it can be understood that using controlled depth milling to perform multiple cuts on the resin 6 can effectively improve the machining quality of the resulting blind via 8, ensuring its conductivity.

[0047] As can be seen from the above, compared with the prior art, the method for manufacturing large-diameter, high-thickness plug-in blind holes provided in Embodiment 1 has the following advantages: ① In the first lamination operation, this embodiment uses a rigid core plate to replace several prepreg sheets in the prior art. This not only simplifies the lamination process and improves lamination efficiency, but also ensures that the through hole B10 and the through hole A20 have very high alignment / alignment accuracy after the lamination operation and subsequent drilling operation. This provides good technical support for the high-precision dimensions of the plug-in blind holes. ② Before the resin plugging operation, this embodiment uses a protective film 5 with high temperature resistance and removable properties to seal one end of the blind hole base hole 3 facing away from the first core plate 1. This effectively ensures that the resin will not flow out from the closed end of the blind hole base hole 3 during the resin plugging operation, thereby achieving full filling of the blind hole base hole 3 and effectively ensuring the lamination quality of the subsequent process. ③ Compared to printing a thicker / larger amount of resin in one go, the segmented printing method adopted in this embodiment avoids voids in the holes caused by poor resin flow and effectively prevents resin cracking due to differences in the thermal expansion coefficients of copper foil, thus meeting the process requirements for uniform resin filling. Furthermore, the pre-baking operation between adjacent printing operations in this embodiment allows the resin filled in the previous printing operation to initially solidify and expel some volatiles, reducing defects such as air bubbles generated during resin filling in subsequent printing operations, further improving the density of the resin filling and ensuring the lamination quality of subsequent processes. ④ This embodiment utilizes controlled-depth milling to perform multiple cuts on the resin 6, effectively improving the processing quality of the resulting blind holes 8 and ensuring the conductivity of the blind holes. ⑤ The method for manufacturing large-diameter, high-thickness blind holes provided in this embodiment is reasonable, has a simple process flow, and is easy to operate and implement.

[0048] Example 2

[0049] This embodiment 2 provides a PCB board with plug-in blind holes 8 for interfacing with external electrical components, and the plug-in blind holes 8 are manufactured using the large-diameter, high-thickness plug-in blind hole manufacturing method described in embodiment 1 above.

[0050] As can be seen from the above, the blind vias on the PCB board obtained in this embodiment 2 have advantages such as high dimensional accuracy, good structural stability, and good conductivity, which well meet market demands.

[0051] Finally, it should be noted that the prefixes "first," "second," etc., of the component names in this specification (such as first optical core board, second optical core board, etc.) and the suffixes "A," "B," etc., of the component names (such as through hole A, through hole B, etc.) are only for the purpose of clarity of description and are not intended to limit the scope of implementation of this invention patent.

[0052] Many specific details have been set forth in the foregoing description to provide a thorough understanding of the present invention. However, the above description is merely a preferred embodiment of the present invention, and the present invention can be implemented in many other ways different from those described herein. Therefore, the present invention is not limited to the specific embodiments disclosed above. Furthermore, any person skilled in the art can make many possible variations and modifications to the technical solutions of the present invention, or modify them into equivalent embodiments, using the methods and techniques disclosed above, without departing from the scope of the present invention. Any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention, without departing from the content of the present invention, shall still fall within the protection scope of the present invention.

Claims

1. A method for manufacturing blind holes for large-diameter, thick-plate inserts, characterized in that: include: A first optical core plate (1) and a substrate (2) with a through hole A (20) are provided. The first optical core plate (1) is laminated and fixed on one side of the substrate (2). A through hole B (10) is processed on the first optical core plate (1). The through hole B (10) and the through hole A (20) are arranged along the same center line and aligned and connected to form a blind hole base hole (3). A conductive copper layer (4) of a predetermined thickness is plated on the inner wall of the blind hole base hole (3). A protective film (5) with high temperature resistance and removability is used to seal one end of the blind hole base hole (3) facing away from the first optical core plate (1), and then resin (6) is filled into the blind hole base hole (3) through a resin plugging process. After the resin (6) has cured or semi-cured, the protective film (5) is removed, and the second optical core plate (7) is laminated and fixed on the side of the substrate (2) facing away from the first optical core plate (1). The resin (6) is cut multiple times using controlled depth milling until the conductive copper layer (4) set on the inner wall of the blind hole base hole (3) is completely exposed. At the same time, the conductive copper layer (4) is also cut to a set thickness, that is, a plug-in blind hole (8) with a part of the second optical core board (7) as the hole bottom is formed.

2. The method for manufacturing large-diameter, high-thickness blind holes for inserts according to claim 1, characterized in that: Both the first optical core board (1) and the second optical core board (7) are rigid optical core boards with the surface copper layer removed.

3. The method for manufacturing blind holes for large-diameter, high-thickness inserts according to claim 2, characterized in that: The rigid optical core plate is made of epoxy resin.

4. The method for manufacturing blind holes for large-diameter, high-thickness inserts according to claim 2, characterized in that: First, a positioning target is drilled on the substrate (2), and then the through hole A (20) is drilled on the substrate (2) based on the positioning target. Also, the through hole B (10) is drilled on the first optical core plate (1) based on the positioning target, so as to ensure that the through hole B (10) and the through hole A (20) are arranged on the same center line.

5. The method for manufacturing blind holes for large-diameter, high-thickness inserts according to claim 1, characterized in that: While depositing the conductive copper layer (4) on the inner wall of the blind hole base hole (3) through copper plating and electroplating processes, copper plating layers (9) are also deposited on the opposite sides of the first optical core board (1) and the substrate (2). The two copper plating layers (9) are smoothly connected to the two ends of the conductive copper layer (4), and the copper thickness of the conductive copper layer (4) is... With respect to the copper thickness of the copper plating layer (9) They respectively satisfy the following relations: ; In the formula, The standard thickness of the preset conductive copper layer, This is the standard inner diameter of the preset blind hole for the plug-in.

6. The method for manufacturing blind holes for large-diameter, high-thickness inserts according to claim 1, characterized in that: The protective film (5) is a high-temperature resistant dry film and is applied to one end of the blind hole base hole (3) facing away from the first optical core plate (1) by a vacuum film application process. In addition, the protective film (5) is separated from one end of the blind hole base hole (3) by mechanical peeling.

7. The method for manufacturing blind holes for large-diameter, high-thickness inserts according to claim 1, characterized in that: The axial depth of the blind hole base hole (3) is not less than 5 mm. Correspondingly, the resin (6) is filled into the blind hole base hole (3) by a segmented screen printing process.

8. The method for manufacturing blind holes for large-diameter, high-thickness inserts according to claim 1, characterized in that: The resin (6) is cut twice, wherein the diameter of the drill bit used in the first cut is... The diameter of the drill bit used in the second cutting. They respectively satisfy the following relations: ; In the formula, This is the standard inner diameter of the preset blind hole for the plug-in.

9. A PCB board, characterized in that: The device is provided with plug-in blind holes (8) for interfacing with external electrical components. The plug-in blind holes (8) are manufactured using the manufacturing method of large-diameter, high-thickness plug-in blind holes as described in any one of claims 1-8.

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