Circuit board manufacturing method for preventing repeated drilling of back drill and circuit board

Abstract

The invention relates to the field of printed circuit boards, and discloses a circuit board manufacturing method capable of preventing repeated drilling of a back drill and a circuit board, the circuit board manufacturing method capable of preventing repeated drilling of the back drill comprises the following steps: providing a substrate, the substrate comprises a test hole site and a back drill area, the test hole site has conductivity, and the back drill area has conductivity; electroplating through holes to be subjected to back drilling are formed in the back drilling area; processing a first hole in the test hole site, wherein the depth of the first hole is smaller than or equal to the thickness of the substrate; carrying out back drilling processing on the electroplated through hole; a second hole is machined in the testing hole position, the second hole and the first hole are coaxially arranged, the hole diameter of the second hole is larger than that of the first hole, and the second hole penetrates through the substrate. According to the circuit board manufacturing method for preventing repeated drilling of the back drill and the circuit board provided by the invention, the problem that the circuit board is scrapped due to repeated drilling during back drill can be improved.

Description

Technical Field

[0001] The present application relates to the field of printed circuit boards, and in particular to a method for manufacturing a circuit board and a circuit board for preventing back drilling and repeated drilling. Background Art

[0002] With the development of 5G communication technology, the reflection, scattering, delay and other interferences of circuit boards on signal transmission will cause "distortion" of signals and affect signal integrity. In order to reduce signal distortion, a backdrilling process is required to remove excess copper from the hole wall of the electroplated through hole to ensure signal integrity.

[0003] Among them, back drilling is to use the depth-controlled drilling method on the electroplated through-hole to accurately remove the unnecessary copper of the electroplated through-hole through the drilling equipment. These unnecessary parts of the hole copper are called stub. Because the depth control sets a fixed depth to control the stub within the required range, the stub will be drilled to a fixed depth with the zero position detected by the drill tip of the drill.

[0004] Usually, the zero position is calculated when the drill tip contacts the copper layer on the board surface of the circuit board and forms a loop with the mushroom head. When repeated drilling occurs due to human factors, when the drill tip drills down to the drilled electroplated through hole, the loop induction will calculate the zero position when the side edge of the drill tip collides with the surface copper of the hole wall of the electroplated through hole. Due to the different sensing positions, the depth changes, and the excess length cannot be controlled within the required range, which leads to the scrapping of the circuit board. Summary of the invention

[0005] The present application provides a circuit board manufacturing method and a circuit board for preventing repeated back drilling, which can improve the problem of circuit board scrapping caused by repeated back drilling.

[0006] In a first aspect, an embodiment of the present application provides a method for manufacturing a circuit board to prevent back drilling and repeated drilling, comprising:

[0007] Providing a substrate, the substrate comprising a test hole and a back drilling area, the test hole is conductive, and the back drilling area is provided with a plated through hole to be back drilled;

[0008] Processing a first hole at the test hole position, wherein the depth of the first hole is less than or equal to the thickness of the substrate;

[0009] performing back drilling on the plated through hole;

[0010] A second hole is processed at the test hole position, the second hole is coaxially arranged with the first hole, the aperture of the second hole is larger than the aperture of the first hole, and the second hole passes through the substrate.

[0011] In some embodiments, the depth of the first hole is 1 / 3-1 / 2 of the thickness of the substrate.

[0012] In some embodiments, the test hole positions and the back-drilling areas are both provided in plurality, and one back-drilling area corresponds to at least one test hole position.

[0013] In some embodiments, the number of test holes is M, the number of back drilling areas is N, and both M and N are positive integers greater than or equal to 2; after providing the substrate, the method for manufacturing a circuit board for preventing repeated back drilling includes:

[0014] Processing the first hole at the N-1th test hole position, wherein the depth of the first hole is less than or equal to the thickness of the substrate;

[0015] Performing back drilling on the plated through hole in the M-1th back drilling area;

[0016] A second hole is machined at the N-1th test hole position, the second hole is coaxially arranged with the first hole, the aperture of the second hole is larger than the aperture of the first hole, and the second hole passes through the substrate;

[0017] Processing the first hole at the Nth test hole position, wherein the depth of the first hole is less than or equal to the thickness of the substrate;

[0018] Performing back drilling on the plated through hole in the Mth back drilling area;

[0019] A second hole is processed at the Nth test hole position, the second hole is coaxially arranged with the first hole, the aperture of the second hole is larger than the aperture of the first hole, and the second hole passes through the substrate.

[0020] In some embodiments, the diameter of the first hole is 0.3 mm-1.0 mm, and the diameter of the second hole is greater than 1.0 mm.

[0021] In some embodiments, the diameter of the first hole is 0.5 mm, and the diameter of the second hole is 3.1 mm.

[0022] In some embodiments, a first drill bit is used to machine a first hole at the test hole position; and before back-drilling the plated through hole, a label hole is machined on the substrate using the first drill bit.

[0023] In some embodiments, a second drill bit is used to machine a second hole at the test hole position; after the plated through hole is back-drilled, the second drill bit is used to machine an identification hole on the substrate.

[0024] In some embodiments, the test hole is located at a process edge of the substrate.

[0025] In a second aspect, an embodiment of the present application provides a circuit board, which is manufactured by the circuit board manufacturing method for preventing back drilling and repeated drilling as described in the first aspect.

[0026] The method for manufacturing a circuit board that prevents repeated back drilling provided in the embodiment of the present application has the beneficial effect that: since a first hole is firstly processed at the test hole position, the depth of the first hole is less than or equal to the thickness of the substrate, and then the plated through hole is back drilled, and finally a second hole is processed at the test hole position, and the second hole is coaxially arranged with the first hole, the aperture of the second hole is larger than the aperture of the first hole, and the second hole passes through the substrate, when the substrate is not removed from the board for repeated drilling, the starting position of the drilling is the test hole position, because the test hole position has been drilled through by the second hole, the drill tip of the drilling equipment cannot contact any conductive part on the substrate, and thus cannot form an induction loop, and the drilling equipment cannot sense and will stop alarming, and manual inspection of the drilling equipment stop alarm information can timely discover it, thereby avoiding the problem of scrapping the substrate due to repeated drilling.

[0027] The beneficial effects of the circuit board provided in the present application compared with the prior art can be referred to the description of the beneficial effects of the circuit board manufacturing method for preventing back drilling and repeated drilling provided in the present application compared with the prior art, which will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0029] Figure 1 is a flow chart of a method for manufacturing a circuit board for preventing back drilling and repeated drilling in one embodiment of the present application;

[0030] Figure 2 This is a schematic diagram of the structure of a substrate in one of the embodiments of the present application;

[0031] Figure 3 is Figure 2 A schematic diagram of machining a first hole at a test hole position of a substrate shown;

[0032] Figure 4 Yes Figure 2 Schematic diagram of back drilling of plated through holes of a substrate shown;

[0033] Figure 5 is Figure 4 The schematic diagram of machining a second hole at the test hole position of the substrate is shown.

[0034] The meanings of the marks in the figure are:

[0035] 100. Substrate;

[0036] 10. Test hole position; 20. Plated through hole; 30. First hole; 40. Second hole. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0038] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0039] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0040] References to "one embodiment", "some embodiments" or "an embodiment" described in the specification of this application mean that a particular feature, structure or characteristic described in conjunction with the embodiment is included in one or more embodiments of the present application. Thus, the phrases "in one embodiment", "in some other embodiments", "in some other embodiments", etc., which appear at different places in this specification, do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. In addition, in one or more embodiments, particular features, structures or characteristics may be combined in any suitable manner.

[0041] In order to illustrate the technical solution of the present application, a description is given below in conjunction with specific drawings and embodiments.

[0042] With the development of 5G communication technology, the reflection, scattering, delay and other interferences of circuit boards on signal transmission will cause "distortion" of signals and affect signal integrity. In order to reduce signal distortion, a backdrilling process is required to remove excess copper from the hole wall of the electroplated through hole to ensure signal integrity.

[0043] Among them, back drilling is to use the depth-controlled drilling method on the electroplated through-hole to accurately remove the unnecessary copper of the electroplated through-hole through the drilling equipment. These unnecessary parts of the hole copper are called stub. Because the depth control sets a fixed depth to control the stub within the required range, the stub will be drilled to a fixed depth with the zero position detected by the drill tip of the drill.

[0044] Usually, the zero position is calculated when the drill tip contacts the copper layer on the board surface of the circuit board and forms a loop with the mushroom head. When repeated drilling occurs due to human factors, when the drill tip drills down to the drilled electroplated through hole, the loop induction will calculate the zero position when the side edge of the drill tip collides with the surface copper of the hole wall of the electroplated through hole. Due to the different sensing positions, the depth changes, and the excess length cannot be controlled within the required range, which leads to the scrapping of the circuit board.

[0045] In view of this, the present application provides a circuit board manufacturing method and circuit board that prevent back drilling and repeated drilling. Since a first hole is first processed at a test hole position, and the depth of the first hole is less than or equal to the thickness of the substrate, and then the plated through hole is back drilled, and finally a second hole is processed at the test hole position, and the second hole is coaxially arranged with the first hole, the aperture of the second hole is larger than the aperture of the first hole, and the second hole passes through the substrate, so when the substrate is not repeatedly drilled, the starting position of the drilling is the test hole position. Because the test hole position has been drilled through by the second hole, the drill nozzle of the drilling equipment cannot contact any conductive part on the substrate, and thus cannot form an induction loop. The drilling equipment cannot sense and will stop alarming. After manually checking the drilling equipment shutdown alarm information, it can be discovered in time to avoid the problem of scrapping the substrate due to repeated drilling.

[0046] Please refer to Figures 1 to 5 , Figure 1 is a flow chart of a method for manufacturing a circuit board for preventing back drilling and repeated drilling in one embodiment of the present application. Figure 2 is a schematic diagram of the structure of a substrate 100 in one embodiment of the present application. Figure 3 is Figure 2 The schematic diagram of processing the first hole 30 at the test hole position 10 of the substrate 100 is shown. Figure 4 Yes Figure 2 The schematic diagram of the back drilling process of the plated through hole 20 of the substrate 100 is shown. Figure 5 is Figure 4 The schematic diagram shown is a schematic diagram of processing a second hole 40 at the test hole position 10 of the substrate 100.

[0047] In a first aspect, an embodiment of the present application provides a method for manufacturing a circuit board to prevent back drilling and repeated drilling, comprising:

[0048] S100: providing a substrate 100, the substrate 100 comprising a test hole 10 and a back drilling area, the test hole 10 is conductive, and the back drilling area is provided with a plated through hole 20 to be back drilled.

[0049] Specifically, the test hole position 10 and the back drilling area are both provided in plurality, the substrate 100 may include multiple circuit layers, the circuit layers may be copper layers, the inner wall of the electroplated through hole 20 is provided with a conductive layer, the conductive layer may be a copper layer, and the hole copper is electrically connected to at least two circuit layers. The substrate 100 may be provided with surface copper, and the surface copper includes the test hole position 10.

[0050] It is understandable that the test hole 10 can be disposed at the process edge of the substrate 100 or other locations where no circuits are disposed.

[0051] S200 : machining a first hole 30 at the test hole position 10 , wherein the depth of the first hole 30 is less than or equal to the thickness of the substrate 100 .

[0052] Specifically, the first hole 30 can be machined at the test hole position 10 using a drill bit of a drilling device. When the drill tip of the drill bit contacts the test hole position 10 and forms a loop with the mushroom head, the zero position is calculated to machine the first hole 30 of a preset depth.

[0053] It is understood that when the depth of the first hole 30 is less than the thickness of the substrate 100, the first hole 30 is a blind hole, and when the depth of the first hole 30 is equal to the thickness of the substrate 100, the first hole 30 is a through hole. In the illustrated embodiment, the first hole 30 is a blind hole.

[0054] S300 : back drilling the plated through hole 20 .

[0055] Specifically, another drill tip of the drilling equipment can be used to back-drill the plated through hole 20 , and the side edge of the drill tip collides with the surface copper of the hole wall of the plated through hole 20 to calculate the zero position, thereby back-drilling the plated through hole 20 .

[0056] For example, production materials are set up, the drill bit is arranged, the conductive mushroom head is pressed on the board surface of the substrate 100 to conduct electricity, and the production is started. The drilling equipment forms a loop according to the drill tip of the drill bit, the board surface (copper surface) of the substrate 100 and the conductive mushroom head to sense the board surface height (back drilling depth zero position), and drills according to the preset depth set in the materials to back drill the plated through hole 20. After the drilling equipment completes the drilling program, the shutdown alarm prompts that the program is 100% completed.

[0057] S400 : machining a second hole 40 at the test hole position 10 , wherein the second hole 40 is coaxially arranged with the first hole 30 , the aperture of the second hole 40 is larger than the aperture of the first hole 30 , and the second hole 40 penetrates the substrate 100 .

[0058] Specifically, another drill bit of the drilling equipment can be used to machine the second hole 40 at the test hole position 10, and the inner hole wall of the second hole 40 has no conductivity.

[0059] It is understandable that after back-drilling all the plated through holes 20 in the back-drilling area, the second hole 40 is processed at the test hole position 10. The drilling sequence on the substrate 100 starts with the depth-controlled drilling of the first hole 30 at the test hole position 10 and ends with the drilling of the second hole 40 at the test hole position 10, and the drilling is terminated.

[0060] It can also be understood that the normal production process is to manually remove the substrate 100 that has been back-drilled, and then put the substrate 100 that has not been back-drilled on for production processing. However, when the substrate 100 that has been back-drilled is not removed due to manual reasons, and the machine is directly started for repeated drilling, the starting position of the drilling is the test hole position 10. Because the test hole position 10 has been drilled through by the second hole 40, the drill bit of the drilling equipment for processing the first hole 30 cannot contact any conductive part on the substrate 100, and thus cannot effectively close the loop circuit and cannot trigger the board surface zero position sensed by the drilling equipment. The drilling equipment stops and alarms, indicating that the drilling position height is out of tolerance. After manually checking the drilling equipment shutdown alarm information, it can be discovered in time, thereby avoiding the quality risks caused by the inconsistent board surface zero position sensed by the drilling equipment due to repeated back drilling.

[0061] As can be seen from the above, the circuit board manufacturing method for preventing back drilling and repeated drilling provided in the embodiment of the present application is that the first hole 30 is firstly processed at the test hole position 10, and the depth of the first hole 30 is less than or equal to the thickness of the substrate 100, and then the plated through hole 20 is back drilled, and finally the second hole 40 is processed at the test hole position 10, and the second hole 40 is coaxially arranged with the first hole 30, and the aperture of the second hole 40 is larger than the aperture of the first hole 30, and the second hole 40 passes through the substrate 100, so when the substrate 100 is not repeatedly drilled, the drilling starting position is the test hole position 10, because the test hole position 10 has been drilled through by the second hole 40, the drill bit of the drilling equipment cannot contact any conductive part on the substrate 100, and thus cannot form an induction loop, and the drilling equipment cannot sense and will stop alarming, and the manual inspection of the drilling equipment shutdown alarm information can timely discover it, thereby avoiding the problem of scrapping the substrate 100 due to repeated drilling.

[0062] The circuit board manufacturing method for preventing repeated back drilling provided in the embodiment of the present application can improve the problem that the substrate 100 is repeatedly back drilled and cannot be accurately identified due to human factors, resulting in the scrapping of the substrate 100, and can ensure that the sensing height of the drilling equipment is on the surface of the substrate 100, ensure that the back drilling depth is fixed, and at the same time, the sensing height of the drilling equipment is not misled, and the excess length Stub is controlled within the production range.

[0063] Optionally, machining the first hole 30 at the test hole position 10 , back-drilling the plated through hole 20 , and machining the second hole 40 at the test hole position 10 are all performed from the same side of the substrate 100 .

[0064] Such an arrangement can avoid turning over the substrate 100 during the processing, thereby improving production efficiency.

[0065] The depth of the first hole 30 is 1 / 3-1 / 2 of the thickness of the substrate 100 .

[0066] Such a configuration can prevent the depth of the first hole 30 from being too deep and affecting the drilling efficiency, and can also prevent the depth of the first hole 30 from being too shallow and causing the side edge of the drill bit to fail to enter the interior of the substrate 100 .

[0067] Optionally, a plurality of test hole positions 10 and a plurality of back-drilling areas are provided, and one back-drilling area corresponds to at least one test hole position 10 .

[0068] Such arrangement can avoid the problem of the substrate 100 being scrapped due to repeated drilling.

[0069] In this embodiment, M test hole positions 10 are provided, and N back drilling areas are provided, where both M and N are positive integers greater than or equal to 2.

[0070] After providing the substrate 100, the method for manufacturing a circuit board to prevent back drilling and repeated drilling includes:

[0071] First, a first hole 30 is processed at the N−1th test hole position 10 , and a depth of the first hole 30 is less than or equal to the thickness of the substrate 100 .

[0072] Next, the plated through hole 20 in the M-1th back-drilled area is back-drilled.

[0073] Again, a second hole 40 is processed at the N−1th test hole position 10 . The second hole 40 is coaxially arranged with the first hole 30 . The aperture of the second hole 40 is larger than that of the first hole 30 . The second hole 40 passes through the substrate 100 .

[0074] Next, a first hole 30 is processed at the Nth test hole position 10 , and the depth of the first hole 30 is less than or equal to the thickness of the substrate 100 .

[0075] Then, the plated through hole 20 in the Mth back-drilled area is back-drilled.

[0076] Finally, a second hole 40 is processed at the Nth test hole position 10 . The second hole 40 is coaxially arranged with the first hole 30 . The aperture of the second hole 40 is larger than that of the first hole 30 . The second hole 40 passes through the substrate 100 .

[0077] By adopting the above solution, it is possible to simultaneously monitor whether multiple back-drilling areas are repeatedly drilled.

[0078] It should be noted that the substrate 100 may include multiple sets (finished product delivery units), and the number of test hole positions 10 is set according to the number of sets. One test hole position 10 is set for each set, and when drilling, first complete the controlled depth drilling of the first hole 30 of the test hole position 10 corresponding to the first set, then complete the back drilling of the plated through hole 20 in the back drilling area of ​​the first set, and finally complete the drilling of the second hole 40 of the test hole position 10 corresponding to the first set, and then start the controlled depth drilling of the first hole 30 of the test hole position 10 corresponding to the second set... and so on.

[0079] Optionally, the diameter of the first hole 30 is 0.3 mm-1.0 mm, and the diameter of the second hole 40 is greater than 1.0 mm.

[0080] Such a configuration can improve the drilling efficiency and prevent the first hole 30 and the second hole 40 from occupying a large space of the substrate 100 .

[0081] For example, the diameter of the first hole 30 is 0.5 mm, and the diameter of the second hole 40 is 3.1 mm.

[0082] Such a configuration can improve the drilling efficiency and prevent the first hole 30 and the second hole 40 from occupying a large space of the substrate 100 .

[0083] Please refer to Figure 2 and Figure 3 In this embodiment, a first drill bit is used to process a first hole 30 at the test hole position 10; before back-drilling the plated through hole 20, a letter mark hole is processed on the substrate 100 using the first drill bit.

[0084] By adopting the above solution, the first drill bit can be used for processing the first hole 30 and processing the letter mark hole, thereby saving the tool change time of the drilling equipment and improving the drilling efficiency.

[0085] It can be understood that, compared with using other drill bits to process the letter mark holes on the substrate 100, the embodiment of the present application can use one less drill bit, which saves costs.

[0086] Optionally, a second drill bit is used to machine a second hole 40 at the test hole position 10 ; after back-drilling the plated through hole 20 , an identification hole is machined on the substrate 100 using the second drill bit.

[0087] Such an arrangement enables the second drill bit to be used for processing the second hole 40 and the identification hole, thereby saving tool change time of the drilling equipment and improving drilling efficiency.

[0088] It is understandable that the identification hole can be a hole for identifying the direction of the substrate 100. Compared with using other drill bits to process the identification hole on the substrate 100, the embodiment of the present application can use one less drill bit, which plays a role in saving costs.

[0089] Optionally, the test hole 10 is disposed at a process edge of the substrate 100 .

[0090] Such an arrangement can prevent the subsequent second hole 40 from affecting the normal circuit layout of the circuit board.

[0091] In a second aspect, an embodiment of the present application provides a circuit board, which is manufactured by the circuit board manufacturing method for preventing back drilling and repeated drilling as in the first aspect.

[0092] The circuit board provided in the embodiment of the present application is processed by first processing the first hole 30 at the test hole position 10, the depth of the first hole 30 is less than or equal to the thickness of the substrate 100, and then the plated through hole 20 is back-drilled, and finally the second hole 40 is processed at the test hole position 10, and the second hole 40 is coaxially arranged with the first hole 30, the aperture of the second hole 40 is larger than the aperture of the first hole 30, and the second hole 40 passes through the substrate 100, so when the substrate 100 is not lowered and repeatedly drilled, the starting position of the drilling is the test hole position 10, because the test hole position 10 has been drilled through by the second hole 40, the drill bit of the drilling equipment cannot contact any conductive part on the substrate 100, and thus cannot form an induction loop, and the drilling equipment cannot sense and will stop alarming, and the drilling equipment shutdown alarm information can be found in time after manual checking, thereby avoiding the problem of scrapping the substrate 100 due to repeated drilling.

[0093] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A method for manufacturing a circuit board to prevent back drilling and repeated drilling, characterized in that: include: Providing a substrate, the substrate comprising a test hole and a back drilling area, the test hole is conductive, and the back drilling area is provided with a plated through hole to be back drilled; Processing a first hole at the test hole position, wherein the depth of the first hole is less than or equal to the thickness of the substrate; performing back drilling on the plated through hole; A second hole is processed at the test hole position, the second hole is coaxially arranged with the first hole, the aperture of the second hole is larger than the aperture of the first hole, and the second hole passes through the substrate.

2. The method for manufacturing a circuit board to prevent back drilling and repeated drilling according to claim 1, characterized in that: The depth of the first hole is 1 / 3-1 / 2 of the thickness of the substrate.

3. The method for manufacturing a circuit board to prevent back drilling and repeated drilling according to claim 1, characterized in that: A plurality of the test hole positions and the back-drilling areas are provided, and one back-drilling area corresponds to at least one test hole position.

4. The method for manufacturing a circuit board to prevent back drilling and repeated drilling according to claim 3, characterized in that: The number of the test holes is M, the number of the back drilling areas is N, and both M and N are positive integers greater than or equal to 2; After providing the substrate, the method for manufacturing a circuit board to prevent back drilling and repeated drilling includes: Processing the first hole at the N-1th test hole position, wherein the depth of the first hole is less than or equal to the thickness of the substrate; Performing back drilling on the plated through hole in the M-1th back drilling area; A second hole is machined at the N-1th test hole position, the second hole is coaxially arranged with the first hole, the aperture of the second hole is larger than the aperture of the first hole, and the second hole passes through the substrate; Processing the first hole at the Nth test hole position, wherein the depth of the first hole is less than or equal to the thickness of the substrate; Performing back drilling on the plated through hole in the Mth back drilling area; A second hole is processed at the Nth test hole position, the second hole is coaxially arranged with the first hole, the aperture of the second hole is larger than the aperture of the first hole, and the second hole passes through the substrate.

5. The method for manufacturing a circuit board to prevent back drilling and repeated drilling according to claim 1, characterized in that: The diameter of the first hole is 0.3 mm-1.0 mm, and the diameter of the second hole is greater than 1.0 mm.

6. The method for manufacturing a circuit board to prevent back drilling and repeated drilling according to claim 5, characterized in that: The diameter of the first hole is 0.5 mm, and the diameter of the second hole is 3.1 mm.

7. The method for manufacturing a circuit board to prevent back drilling and repeated drilling according to claim 1, characterized in that: A first drill bit is used to process a first hole at the test hole position; and before back-drilling the plated through hole, a label hole is processed on the substrate using the first drill bit.

8. The method for manufacturing a circuit board to prevent back drilling and repeated drilling according to claim 1, characterized in that: A second drill bit is used to machine a second hole at the test hole position; after the plated through hole is back-drilled, the second drill bit is used to machine an identification hole on the substrate.

9. The method for manufacturing a circuit board for preventing back drilling and repeated drilling according to any one of claims 1 to 8, characterized in that: The test hole is arranged at the process edge of the substrate.

10. A circuit board, characterized in that: The circuit board is manufactured by the circuit board manufacturing method for preventing back drilling and repeated drilling as described in any one of claims 1 to 9.

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