Double-sided copper circuit board drilling method and circuit board

Abstract

The application relates to the technical field of printed circuit boards, and discloses a double-sided copper circuit board drilling method and a circuit board. The double-sided copper circuit board drilling method comprises the following steps: providing a circuit board, the circuit board comprising an intermediate layer, a first metal layer and a second metal layer, the intermediate layer comprising a dielectric layer, the first metal layer being provided with a first drilling slot, and the second metal layer being provided with a second drilling slot; machining a first hole on the intermediate layer from the first drilling slot, the hole diameter of the first hole being A; machining a second hole on the intermediate layer from the first drilling slot, the hole diameter of the second hole being B, and B < A; machining a third hole on the intermediate layer from the second drilling slot, the hole diameter of the third hole being C; C = A, the third hole being in communication with the first hole; or C > A, the third hole penetrating through the intermediate layer. The double-sided copper circuit board drilling method and the circuit board can solve the problem that the bottom hole opening falls off the dielectric layer when drilling the circuit board in the prior art, and ensure the normal use of the circuit board.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of printed circuit boards, and particularly relates to a double-sided copper circuit board drilling method and a circuit board. BACKGROUND

[0002] A circuit board is usually designed with NPTH (None Plating Through Hole) holes for fixing with other devices, which are usually made by mechanical drilling. In the process of processing NPTH holes of a double-sided copper circuit board, a portion of double-sided copper of the circuit board is usually etched to form a drilling slot, and then drilling is performed at the position where the copper is removed.

[0003] In the related art, due to the height difference between the drilling slot and the copper surface, the drilling slot is suspended and cannot be in contact with the bottom pad, so that when drilling is performed on the circuit board, the bottom hole port may drop the dielectric layer, affecting the normal use of the circuit board. SUMMARY

[0004] The present application provides a double-sided copper circuit board drilling method and a circuit board, which can improve the problem that the bottom hole port drops the dielectric layer when drilling is performed on the circuit board in the related art, and ensure the normal use of the circuit board.

[0005] In a first aspect, an embodiment of the present application provides a double-sided copper circuit board drilling method, comprising:

[0006] A circuit board is provided, which comprises a middle layer and first and second metal layers respectively arranged on opposite sides of the middle layer, the middle layer comprises a dielectric layer, the first metal layer is provided with a first drilling slot, and the second metal layer is provided with a second drilling slot corresponding to the first drilling slot;

[0007] A first hole is processed on the middle layer by the first drilling slot, the depth of the first hole is less than the thickness of the middle layer, and the hole diameter of the first hole is A;

[0008] A second hole is processed on the middle layer by the first drilling slot, the second hole is coaxially arranged with the first hole, the second hole penetrates through the middle layer, the hole diameter of the second hole is B, and B < A;

[0009] A third hole is processed on the middle layer by the second drilling slot, the third hole is coaxially arranged with the second hole, and the hole diameter of the third hole is C; wherein,

[0010] C = A, the third hole is in communication with the first hole;

[0011] Alternatively, C > A, and the third hole penetrates through the middle layer.

[0012] In some embodiments, the first hole has a depth of 1 / 3 to 1 / 2 of the thickness of the intermediate layer, C=A.

[0013] In some embodiments, A / 3≤B≤A / 2.

[0014] In some embodiments, the circuit board comprises an alignment target; the first hole is formed on the intermediate layer by the first drilling slot based on the alignment target; the second hole is formed on the intermediate layer by the first drilling slot based on the alignment target.

[0015] In some embodiments, the alignment target is disposed on the first metal layer.

[0016] In some embodiments, the third hole is formed on the intermediate layer by the second drilling slot based on the second hole.

[0017] In some embodiments, the first hole is formed on the intermediate layer by the first drilling slot using a CCD drilling machine with Cmk≥2.0; and / or, the second hole is formed on the intermediate layer by the first drilling slot using a CCD drilling machine with Cmk≥2.0; and / or, the third hole is formed on the intermediate layer by the second drilling slot using a CCD drilling machine with Cmk≥2.0.

[0018] In some embodiments, the medium layer comprises a first medium layer and a second medium layer, the intermediate layer further comprises a metal substrate, the first medium layer is located between the metal substrate and the first metal layer, the first medium layer defines a bottom surface of the first drilling slot, and the first hole penetrates through the first medium layer; the second medium layer is located between the metal substrate and the second metal layer, and the second medium layer defines a bottom wall of the second drilling slot.

[0019] In some embodiments, before the circuit board is provided, the double-sided copper circuit board drilling method further comprises:

[0020] etching to remove part of the first metal layer to form the first drilling slot;

[0021] and / or, etching to remove part of the second metal layer to form the second drilling slot.

[0022] In a second aspect, the embodiments of the present application provide a circuit board, which is made by the double-sided copper circuit board drilling method according to the first aspect.

[0023] The double-sided copper circuit board drilling method provided by the embodiments of the present application has the following beneficial effects:

[0024] Firstly, the first hole is processed on the middle layer by the first drilling groove, the depth of the first hole is less than the thickness of the middle layer, so the cutting amount is reduced, and the first hole is a blind hole, which is not easy to appear burr problem, the end of the first hole is the middle layer, even if there is a small amount of burr, it also stays in the middle layer, which is convenient for subsequent removal, and reduces the cutting amount of processing the second hole and the third hole.

[0025] Then, the second hole is processed on the middle layer by the first drilling groove, the second hole is coaxially arranged with the first hole, the second hole penetrates the middle layer, which can provide a positioning reference for subsequent processing of the third hole, at this time, the effective drilling depth is only a part, and even if the medium layer of the side wall falls off, it only appears at the edge of the second hole.

[0026] Finally, the third hole is processed on the middle layer by the second drilling groove, and C=A or C>A, not only can the medium layer falling off generated by processing the second hole and the third hole be removed, but also because the cutting amount when processing the third hole is small, the burr problem can be greatly avoided.

[0027] The double-sided copper circuit board drilling method and the circuit board provided by the application can improve the problem that the bottom hole will fall off the medium layer when drilling on the circuit board in the related art, and ensure the normal use of the circuit board.

[0028] The beneficial effects of the circuit board provided by the application compared to the prior art can be referred to the beneficial effects of the double-sided copper circuit board drilling method provided by the application compared to the prior art, which will not be described here. BRIEF DESCRIPTION OF DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the application, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description only some embodiments of the application, and for those skilled in the art, other drawings can also be obtained without creative labor.

[0030] Figure 1 is a schematic diagram of processing NPTH hole in the circuit board in the prior art;

[0031] Figure 2 is a flow chart of the double-sided copper circuit board drilling method in one of the embodiments of the application;

[0032] Figure 3 is a schematic diagram of processing the first hole on the circuit board in one of the embodiments of the application;

[0033] Figure 4 is a schematic diagram of processing the second hole on the circuit board shown in Figure 3 ; and

[0034] Figure 5 is a schematic view of a circuit board shown in Figure 4 is a schematic view of a circuit board shown in

[0035] Figure 6 is a schematic view of a circuit board shown in Figure 4 is a schematic view of a circuit board shown in

[0036] The meanings of the marks in the figures are as follows:

[0037] 1, circuit board; 2, NPTH hole; 3, burr;

[0038] 10, intermediate layer; 11, substrate; 12, first dielectric layer; 13, second dielectric layer;

[0039] 20, first metal layer; 21, first drilling slot;

[0040] 30, second metal layer; 31, second drilling slot;

[0041] 40, first hole;

[0042] 50, second hole;

[0043] 60, third hole. DETAILED DESCRIPTION

[0044] In order to make the purpose, technical scheme and advantages of the present application clearer, the present application will be further described in detail below in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application and do not limit the present application.

[0045] 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.

[0046] In addition, the terms "first", "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise specifically limited.

[0047] Reference to "one embodiment", "some embodiments", "an embodiment" or "embodiments" in the present application description means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the application. The appearances of the phrases "in one embodiment", "in some embodiments", "in other embodiments", "in additional embodiments" and so on in various places in the specification are not necessarily all referring to the same embodiment, but can refer to one or more but not all embodiments unless otherwise specified. Furthermore, the particular features, structures, or characteristics can be combined in any suitable manner in one or more embodiments.

[0048] To illustrate the technical solutions of the present application, the following will be described in conjunction with specific drawings and embodiments.

[0049] Please refer to Figure 1 The circuit board 1 is usually designed with NPTH holes 2 for fixing with other devices, which are usually made by mechanical drilling. During the process of processing NPTH holes 2, the double-sided copper circuit board 1 usually first removes a part of the double-sided copper to form a drilling slot, and then drills a hole in the position where the copper is removed.

[0050] In the related art, due to the height difference between the drilling slot and the copper surface, the drilling slot is suspended and cannot contact the bottom pad, so when drilling on the circuit board 1, problems such as the bottom hole falling off the dielectric layer and generating burrs 3 will occur. The dielectric layer falling off will cause the circuit board 1 to be uneven, not only affecting the appearance of the circuit board 1, but also possibly causing the NPTH hole 2 to be suspended, affecting the installation of the circuit board 1.

[0051] In view of this, the present application provides a double-sided copper circuit board drilling method and circuit board:

[0052] First, a first hole is processed on the middle layer by the first drilling slot, and the depth of the first hole is less than the thickness of the middle layer, so the cutting amount is reduced, and the first hole is a blind hole, which is not prone to burr problems. The end of the first hole is the middle layer, so even if there is a small amount of burr, it will stay in the middle layer, which is convenient for subsequent removal and reduces the cutting amount of processing the second hole and the third hole.

[0053] Then, a second hole is processed on the middle layer by the first drilling slot, and the second hole is coaxially arranged with the first hole, and the second hole penetrates the middle layer, which can provide a positioning reference for subsequent processing of the third hole. At this time, the effective drilling depth is only a part of it, and even if the dielectric layer on the side wall falls off, it will only occur at the edge of the second hole.

[0054] Finally, the third hole is processed on the middle layer by the second drilling slot, and C=A or C>A, which not only removes the burrs and the detached medium layer generated by processing the second hole and the third hole, but also greatly avoids the burr problem because the cutting amount is small when processing the third hole.

[0055] The double-sided copper circuit board drilling method and the circuit board provided by the application can improve the problem of medium layer falling off the bottom hole during drilling on the circuit board in the related art, and ensure normal use of the circuit board.

[0056] Please refer to Figures 2 to 6 , in a first aspect, the embodiments of the application provide a double-sided copper circuit board drilling method, comprising:

[0057] S100: providing a circuit board, the circuit board comprising a middle layer 10 and first and second metal layers 20 and 30 respectively arranged on opposite sides of the middle layer 10, the middle layer 10 comprising a medium layer, the first metal layer 20 being provided with a first drilling slot 21, and the second metal layer 30 being provided with a second drilling slot 31 corresponding to the first drilling slot 21.

[0058] Specifically, the middle layer 10 can include a metal substrate 11 and a medium layer, etc., the metal substrate 11 can include a copper base, an aluminum base or a copper-aluminum composite base, etc., and the medium layer can include a semi-cured sheet (PP, Prepreg), a polyimide (PI, Polyimide), a polytetrafluoroethylene (PTFE, Polytetrafluoroethylene), an epoxy resin composition or a modified epoxy resin composition, etc. The first and second metal layers 20 and 30 can each include a copper layer, a silver layer or an aluminum layer, etc. The circuit board can have undergone processes such as cutting, pre-pressing treatment, pre-lamination, first pressing, X-RAY target drilling machine, first edge milling, outer layer circuit, outer layer AOI (Automated Optical Inspection), first solder mask, characters and gold plating, etc.

[0059] Cutting: cutting the core plate and the metal substrate 11 according to requirements.

[0060] Pre-pressing treatment: processing the metal substrate 11 according to normal parameters to increase the bonding force of the metal substrate 11.

[0061] Pre-lamination: manufacturing according to the lamination structure.

[0062] First pressing: manufacturing according to normal pressing process; mixing pressing is not allowed in the same pressing opening.

[0063] X-RAY target drilling machine: manufacturing according to the requirements of resin plug hole targeting.

[0064] First edge milling: removing excess frame waste.

[0065] Outer layer circuit: normal production circuit.

[0066] Outer layer AOI: 100% full inspection to confirm whether the outer layer circuit meets the product design requirements.

[0067] One-time solder mask: normal production solder mask oil.

[0068] Characters: normal production of text.

[0069] Gold plating: normal production.

[0070] S200: A first drilling groove 21 is used to process a first hole 40 on the middle layer 10, the depth of the first hole 40 is less than the thickness of the middle layer 10, and the diameter of the first hole 40 is A.

[0071] Specifically, the circuit board can be placed on the base plate with the first drilling groove 21 facing up, and a drill is used to process the first hole 40 on the middle layer 10.

[0072] S300: A first drilling groove 21 is used to process a second hole 50 on the middle layer 10, the second hole 50 is coaxially arranged with the first hole 40, the second hole 50 penetrates the middle layer 10, the diameter of the second hole 50 is B, and B < A.

[0073] Specifically, the circuit board can be placed on the base plate with the first drilling groove 21 facing up, and a drill is used to process the second hole 50 on the middle layer 10.

[0074] S400: A second drilling groove 31 is used to process a third hole 60 on the middle layer 10, the third hole 60 is coaxially arranged with the second hole 50, and the diameter of the third hole 60 is C; in this embodiment, C = A, and the third hole 60 communicates with the first hole 40. Alternatively, in another embodiment, C > A, and the third hole 60 penetrates the middle layer 10.

[0075] Specifically, the circuit board can be placed on the base plate with the second drilling groove 31 facing up, and a drill is used to process the third hole 60 on the middle layer 10. The diameter of the third hole 60 is the finished product diameter.

[0076] For example, C = 1.5 mm, and A = 1.5 mm.

[0077] As can be seen from the above, the double-sided copper circuit board drilling method provided by the embodiments of the present application has the following advantages:

[0078] First, a first drilling groove 21 is used to process a first hole 40 on the middle layer 10, the depth of the first hole 40 is less than the thickness of the middle layer 10, so the cutting amount is reduced, and the first hole 40 is a blind hole, which is not prone to burr problems, the end of the first hole 40 is the middle layer 10, even if there is a small amount of burr, it stays on the middle layer 10, which facilitates subsequent removal, and reduces the cutting amount of processing the second hole 50 and the third hole 60.

[0079] Then, the second hole 50 is processed on the intermediate layer 10 by the first drilling groove 21, the second hole 50 is coaxially arranged with the first hole 40, the second hole 50 penetrates the intermediate layer 10, and can provide a positioning reference for subsequent processing of the third hole 60, at this time, the effective drilling depth is only a part, and even if the medium layer of the side wall falls off, it only appears at the edge of the second hole 50.

[0080] Finally, the third hole 60 is processed on the intermediate layer 10 by the second drilling groove 31, and C=A or C>A, not only can the burr and the falling medium layer generated by processing the second hole 50 and the third hole 60 be removed, but also because the cutting amount when processing the third hole 60 is small, the burr problem can be greatly avoided.

[0081] The double-sided copper circuit board drilling method and the circuit board provided by the application can improve the problems of medium layer falling off from the bottom hole and burr generated when drilling the circuit board in the related art, and ensure the normal use of the circuit board.

[0082] It should be noted that although a small amount of burr may still appear in the double-sided copper circuit board drilling method provided by the embodiment of the application, the burr is only attached to the intermediate layer 10 at this time, which does not affect the finished hole diameter of the third hole 60, and the drilling quality is greatly improved.

[0083] Optionally, after the third hole 60 is processed on the intermediate layer 10 by the second drilling groove 31, the finished plate milling, testing, FQC (Final Quality Control), FQA (Factory Quality Assurance) and packaging processes can be continued.

[0084] Finished plate milling: normally complete the plate milling.

[0085] Testing: normally test the circuit board product.

[0086] FQC: normally inspect the circuit board product.

[0087] FQA: normally sample the circuit board product.

[0088] Packaging: package and ship after inspection.

[0089] In the embodiment, the depth of the first hole 40 is 1 / 3 to 1 / 2 of the thickness of the intermediate layer 10, and C=A.

[0090] By adopting the above scheme, the cutting amount for processing the first hole 40 can be reduced, and the burr problem can be avoided.

[0091] Optionally, A / 3≤B≤A / 2.

[0092] In this way, the cutting amount of the second hole 50 can be reduced, burr problems can be avoided, and the medium layer can be detached at the edge of the second hole 50, facilitating subsequent removal of the detached medium layer when the third hole 60 is processed.

[0093] For example, A = 1.5 mm, and B = 0.5 mm-0.75 mm.

[0094] For reference Figures 2 to 6 In this embodiment, the circuit board includes an alignment target; the first hole 40 is processed on the intermediate layer 10 by the first drilling slot 21 based on the alignment target; and the second hole 50 is processed on the intermediate layer 10 by the first drilling slot 21 based on the alignment target.

[0095] By using the above scheme, the same alignment target can be used when the first hole 40 and the second hole 50 are processed, and the alignment accuracy of the first hole 40 and the second hole 50 can be improved.

[0096] Optionally, the alignment target is arranged on the first metal layer 20.

[0097] In this way, the alignment target can be conveniently manufactured.

[0098] For example, one alignment target can be reserved at each of the four corners of the waste area of the first metal layer 20 in the outer layer circuit process.

[0099] It should be noted that the alignment target can be a hole or a PAD. Before drilling, the drilling machine can recognize the alignment target through a machine vision system and accurately position it, and at the same time, cooperate with a laser range finder to measure the distance, and then control the drilling unit through the control system to accurately drill.

[0100] Optionally, the third hole 60 is processed on the intermediate layer 10 by the second drilling slot 31 based on the second hole 50.

[0101] In this way, the alignment accuracy of the second hole 50 and the third hole 60 can be improved, thereby improving the alignment accuracy of the first hole 40, the second hole 50, and the third hole 60, and without the need to specially design an alignment through hole on the circuit board to position the third hole 60, the design of the alignment through hole can be reduced, thereby reducing the space of the alignment through hole on the circuit board design, and avoiding waste of the circuit board unit area.

[0102] It should be noted that before drilling, the drilling machine can recognize the second hole 50 through a machine vision system and accurately position it, and at the same time, cooperate with a laser range finder to measure the distance, and then control the drilling unit through the control system to accurately drill the third hole 60.

[0103] As an implementable manner, the first hole 40 is processed by the first drilling slot 21 on the intermediate layer 10 using a CCD (Charge-Coupled Device) drill machine with Cmk (Machine Capability Index) ≥ 2.0; and / or, the second hole 50 is processed by the first drilling slot 21 on the intermediate layer 10 using a CCD drill machine with Cmk ≥ 2.0; and / or, the third hole 60 is processed by the second drilling slot 31 on the intermediate layer 10 using a CCD drill machine with Cmk ≥ 2.0.

[0104] By adopting the above scheme, the drilling deviation can be avoided when the first hole 40, the second hole 50 and the third hole 60 are processed.

[0105] It can be understood that when the first hole 40 and the second hole 50 are processed by the first drilling slot 21 on the intermediate layer 10 using a CCD drill machine with Cmk ≥ 2.0, the four alignment targets reserved at the four corners of the waste area during the outer layer circuit manufacturing can be used for positioning.

[0106] Please refer to Figures 2 to 6 In the embodiment, the medium layer includes a first medium layer 12 and a second medium layer 13, and the intermediate layer 10 further includes a metal substrate 11, the first medium layer 12 is located between the metal substrate 11 and the first metal layer 20, and the first medium layer 12 defines a bottom surface of the first drilling slot 21, and the first hole 40 penetrates the first medium layer 12; the second medium layer 13 is located between the metal substrate 11 and the second metal layer 30, and the second medium layer 13 defines a bottom wall of the second drilling slot 31.

[0107] By adopting the above scheme, the burr and the problem that the first medium layer 12 and the second medium layer 13 fall off from the hole opening of the third hole 60 can be avoided when the third hole 60 is processed.

[0108] It should be noted that even if the edge of the second hole 50 has burrs and the first medium layer 12 and the second medium layer 13 fall off, these burrs and the first medium layer 12 and the second medium layer 13 that fall off will be removed when the third hole 60 is processed. The double-sided copper circuit board drilling method provided in the embodiment can be used for a double-sided thick copper metal-based circuit board.

[0109] The first hole 40 and the third hole 60 are respectively machined from two sides of the circuit board, and are respectively drilled from the outside of the first dielectric layer 12 to the inside of the first dielectric layer 12 and from the outside of the second dielectric layer 13 to the inside of the second dielectric layer 13, so that the problem of the dielectric layer falling due to the drilling impact and the suspended dielectric layer in the prior art can be completely solved, and because the depth of the first hole 40 is 1 / 3 to 1 / 2 of the thickness of the middle layer 10, the second hole 50 only needs to be drilled from more than 2 / 3 of the thickness of the middle layer 10 except the first hole 40, and the burr problem caused by one-time drilling can be avoided by drilling through the second hole 50 and the first hole 40 in the middle layer 10.

[0110] Optionally, before the circuit board is provided, the double-sided copper circuit board drilling method further includes: etching and removing part of the first metal layer 20 to form a first drilling slot 21; and / or etching and removing part of the second metal layer 30 to form a second drilling slot 31.

[0111] In this way, the first drilling slot 21 and the second drilling slot 31 are conveniently made.

[0112] For example, part of the first metal layer 20 and part of the second metal layer 30 can be etched and removed in the outer layer circuit process.

[0113] Please refer to Figures 2 to 6 In a second aspect, the embodiments of the present application provide a circuit board, which is made by the double-sided copper circuit board drilling method of the first aspect.

[0114] The circuit board provided by the present application can improve the problems of the bottom hole falling the dielectric layer and generating burrs when drilling on the circuit board in the related art, and ensure the normal use of the circuit board.

[0115] The above embodiments are only used to illustrate the technical solutions of the present application, but not limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that the technical solutions recorded in the foregoing embodiments can be modified, or some technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application.

Claims

1. A method for drilling holes in a double-sided copper circuit board, characterized in that, The method comprises the following steps: providing a circuit board, the circuit board comprising an intermediate layer, a first metal layer and a second metal layer respectively arranged on two opposite sides of the intermediate layer, the intermediate layer comprising a dielectric layer, the first metal layer being provided with a first drilling slot, and the second metal layer being provided with a second drilling slot corresponding to the first drilling slot; drilling a first hole in the intermediate layer by using the first drilling slot, the first hole having a depth less than the thickness of the intermediate layer and a hole diameter A; drilling a second hole in the intermediate layer by using the first drilling slot, the second hole being coaxially arranged with the first hole, the second hole penetrating through the intermediate layer, the second hole having a hole diameter B, and B < A; drilling a third hole in the intermediate layer by using the second drilling slot, the third hole being coaxially arranged with the second hole, the second hole providing a positioning reference for drilling the third hole, the third hole having a hole diameter C; wherein, C = A, the third hole being in communication with the first hole; or C > A, the third hole penetrating through the intermediate layer. The depth of the first hole is 1 / 3 to 1 / 2 of the thickness of the intermediate layer, and C = A.

2. The double-sided copper circuit board drilling method of claim 1, wherein, A / 3 ≤ B ≤ A / 2.

3. The double-sided copper circuit board drilling method of claim 2, wherein, The circuit board comprises an alignment target, the first hole is drilled in the intermediate layer by using the first drilling slot based on the alignment target, and the second hole is drilled in the intermediate layer by using the first drilling slot based on the alignment target.

4. The method of claim 1 wherein, The alignment target is arranged on the first metal layer.

5. The method of claim 4, wherein, The third hole is drilled in the intermediate layer by using the second drilling slot based on the second hole.

6. The method of claim 4, wherein, The first hole is drilled in the intermediate layer by using the first drilling slot with a CCD drilling machine having a Cmk≥2.0, and / or the second hole is drilled in the intermediate layer by using the first drilling slot with a CCD drilling machine having a Cmk≥2.0, and / or the third hole is drilled in the intermediate layer by using the second drilling slot with a CCD drilling machine having a Cmk≥2.

0.

7. The method of drilling a double-sided copper circuit board of claim 1 wherein, The dielectric layer comprises a first dielectric layer and a second dielectric layer, the intermediate layer further comprising a metal substrate, the first dielectric layer being arranged between the metal substrate and the first metal layer, the first dielectric layer defining a bottom surface of the first drilling slot, and the first hole penetrating through the first dielectric layer.

8. The double-sided copper circuit board drilling method according to any one of claims 1 to 7, characterized by, The second dielectric layer is arranged between the metal substrate and the second metal layer, and the second dielectric layer defines a bottom wall of the second drilling slot. Before the step of providing the circuit board, the method further comprises the following steps:

9. The double-sided copper circuit board drilling method according to any one of claims 1 to 7, characterized by, etching and removing part of the first metal layer to form the first drilling slot; and / or etching and removing part of the second metal layer to form the second drilling slot. The circuit board is manufactured by the method for drilling a double-sided copper circuit board according to any one of claims 1 to 9.

10. A circuit board, characterized by ​

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