Printed circuit board and preparation method thereof

Abstract

The invention discloses a printed circuit board and a preparation method thereof, and the method comprises the steps: obtaining a to-be-processed plate; the to-be-machined plate is subjected to first drilling treatment, so that a plurality of first target holes are formed in the to-be-machined plate in sequence; carrying out second drilling treatment on the to-be-processed plate to sequentially prepare a plurality of second target holes in the to-be-processed plate so as to prepare a printed circuit board; wherein the plurality of first target holes and the plurality of second target holes are alternately arranged in sequence one by one. By means of the mode, the problem that heat cannot be dissipated in time due to the fact that the interval time is too short in the same area can be effectively solved, heat agglomeration in the preparation process is further reduced, the layering situation caused by heating of the conductive layer and the dielectric layer is reduced, and the structural stability and reliability of the printed circuit board are improved.

Description

Technical Field

[0001] The invention is applied to the technical field of printed circuit boards, in particular to a printed circuit board and a preparation method thereof. Background Art

[0002] PCB (Printed Circuit Board), also known as printed circuit board or printed circuit board, is an important electronic component with wide applications. It is the support body of electronic components and also the carrier of electrical connection of electronic components.

[0003] There is a certain heat effect zone in the laser drilling process. If two adjacent holes are processed in sequence, the heat generated by the previous hole has not been dissipated in time, and the heat generated by the next hole follows closely. There is a certain overlap in the heat effect zone, causing local heat agglomeration and overheating.

[0004] Heat accumulation can easily lead to delamination of the conductive layer and the dielectric layer. Summary of the invention

[0005] The invention provides a printed circuit board and a preparation method thereof, so as to solve the problem of heat agglomeration in laser drilling.

[0006] In order to solve the above technical problems, the present invention provides a method for preparing a printed circuit board, comprising: obtaining a board to be processed; performing a first drilling process on the board to be processed to sequentially prepare a plurality of first target holes on the board to be processed; performing a second drilling process on the board to be processed to sequentially prepare a plurality of second target holes on the board to be processed to prepare a printed circuit board; wherein the plurality of first target holes and the plurality of second target holes are alternately arranged one by one in sequence.

[0007] Among them, multiple first target holes and multiple second target holes are arranged in an array to form a drilling area; in the horizontal and vertical directions of the plane where the drilling area is located, multiple first target holes and multiple second target holes are arranged alternately one by one in sequence, so that a corresponding second target hole is set between every two adjacent first target holes, and a corresponding first target hole is set between every two adjacent second target holes.

[0008] Among them, the same first target hole and the same second target hole have the same aperture and / or shape; before the step of obtaining the plate to be processed, the step includes: distinguishing the same first target hole and the same second target hole through front-end setting.

[0009] Among them, after the step of performing a second drilling treatment on the plate to be processed and preparing a plurality of second target holes in sequence on the plate to be processed, it includes: performing a third drilling treatment on the plate to be processed and preparing a plurality of third target holes in sequence on the plate to be processed; the plurality of first target holes, the plurality of second target holes and the plurality of third target holes are arranged alternately one by one in sequence.

[0010] Among them, the step of performing a first drilling treatment on the plate to be processed to sequentially prepare a plurality of first target holes on the plate to be processed includes: performing a first drilling treatment on the plate to be processed by laser direct drilling technology to prepare a plurality of first target holes set at intervals on the plate to be processed; performing a second drilling treatment on the plate to be processed to sequentially prepare a plurality of second target holes on the plate to be processed to prepare a printed circuit board includes: performing a second drilling treatment on the plate to be processed by laser direct drilling technology to prepare a plurality of second target holes correspondingly around the plurality of first target holes to prepare a printed circuit board.

[0011] Among them, the step of obtaining the board to be processed includes: alternately stacking and pressing multiple conductive layers and multiple dielectric layers in sequence to obtain the board to be processed; performing a second drilling process on the board to be processed to prepare multiple second target holes in sequence on the board to be processed to prepare a printed circuit board. The step also includes: electroplating and etching the board to be processed in sequence until a conductive circuit is prepared to obtain a printed circuit board.

[0012] Among them, the steps of electroplating and etching the board to be processed in sequence to form a conductive circuit to obtain a printed circuit board include: electroplating and pattern etching the board to be processed in sequence to prepare a conductive circuit; heat treating the board to be processed; and welding electronic components on the board to be processed to obtain a printed circuit board.

[0013] The temperature of the heat treatment is greater than or equal to the glass transition temperature of the dielectric layer of the plate to be processed.

[0014] In order to solve the above technical problems, the present invention provides a printed circuit board, which is prepared by any of the above printed circuit board preparation methods, including: a circuit board body, on which a plurality of first target holes and a plurality of second target holes are formed, wherein the plurality of first target holes and the plurality of second target holes are arranged alternately one by one.

[0015] Among them, a third target hole is formed on the circuit board body, and multiple first target holes, multiple second target holes and multiple third target holes are arranged alternately in sequence, and the apertures and / or shapes of the first target holes, the second target holes and the third target holes are the same.

[0016] In order to solve the above technical problems, the preparation method of the printed circuit board of the present invention includes: obtaining a board to be processed; performing a first drilling process on the board to be processed to prepare a plurality of first target holes in sequence on the board to be processed; performing a second drilling process on the board to be processed to prepare a plurality of second target holes in sequence on the board to be processed to prepare a printed circuit board; wherein the plurality of first target holes and the plurality of second target holes are alternately arranged one by one in sequence, so as to ensure that when the first drilling process prepares the next adjacent first target hole, there is sufficient spacing between the two first target holes to reduce heat agglomeration during the preparation process, and to ensure that when the second drilling process prepares the next adjacent second target hole, there is sufficient spacing between the two second target holes to reduce heat agglomeration during the preparation process. Moreover, the second drilling process is performed after the first drilling process is completed, so that the processing time interval between adjacent target holes is greatly increased; it can effectively reduce the problem that heat cannot be dissipated in time due to too short an interval in the same area, further reduce heat accumulation in the preparation process, reduce the delamination of the conductive layer and the dielectric layer due to heat, and improve the structural stability and reliability of the printed circuit board. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic flow chart of an embodiment of a method for preparing a printed circuit board provided by the present invention;

[0018] Figure 2 It is a schematic flow chart of another embodiment of the method for preparing a printed circuit board provided by the present invention;

[0019] Figure 3 is a schematic diagram of the arrangement of the first target hole and the second target hole in one embodiment;

[0020] Figure 4 is a schematic diagram of the arrangement of the first target hole and the second target hole in another embodiment;

[0021] Figure 5 It is a schematic structural diagram of an embodiment of a printed circuit board of the present invention. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0024] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0025] See also Figure 1 , Figure 1 The figure is a schematic flow chart of an embodiment of a method for preparing a printed circuit board provided by the present invention.

[0026] Step S11: Obtain the plate to be processed.

[0027] The plate to be processed is a process plate in the process of preparing a printed circuit board, such as a core board that has not been pressed, an intermediate plate after pressing a part of the conductive layer, and an integral plate after pressing. The specific selection of the plate to be processed is set based on actual needs. After each pressing, drilling can be performed according to the drilling method of this embodiment based on needs.

[0028] Step S12: performing a first drilling process on the plate to be processed, so as to sequentially prepare a plurality of first target holes on the plate to be processed.

[0029] The number of the first target holes is set based on actual needs, for example, 10, 20, 30, 50 or 100, etc. The target holes may include blind holes or through holes, and the specific type is set based on actual needs.

[0030] First, the plate to be processed is subjected to a first drilling process, and all first target holes are prepared in sequence.

[0031] Step S13: performing a second drilling process on the plate to be processed, and sequentially preparing a plurality of second target holes on the plate to be processed to prepare a printed circuit board.

[0032] The number of the second target holes is set based on actual needs, for example, 10, 20, 30, 50 or 100, etc. The target holes may include blind holes or through holes, and the specific type is set based on actual needs.

[0033] The plate to be processed is subjected to a second drilling process to prepare all second target holes in sequence.

[0034] Among them, multiple first target holes and multiple second target holes are arranged alternately one by one, that is, when the first drilling process prepares the first target hole, a margin spacing for the subsequent preparation of the second target hole must be reserved between each two adjacent first target holes. When the second drilling process prepares the second target hole, a first target hole must be spaced between each two adjacent second target holes. In a specific application scenario, if there are multiple first target holes 1 and multiple second target holes 2, the arrangement order can be 1, 2, 1, 2, 1, 2...1, 2.

[0035] The above method ensures that when the first drilling process is used to prepare the next adjacent first target hole, there is sufficient spacing between the two first target holes to reduce heat accumulation during the preparation process, and ensures that when the second drilling process is used to prepare the next adjacent second target hole, there is sufficient spacing between the two second target holes to reduce heat accumulation during the preparation process. The second drilling process is performed after the first drilling process is completed, which greatly increases the processing time interval between adjacent target holes; it can effectively avoid the problem that heat cannot be dissipated in time due to too short an interval in the same area, and further reduce heat accumulation during the preparation process.

[0036] Through the above steps, the method for preparing a printed circuit board of this embodiment includes: obtaining a plate to be processed; performing a first drilling process on the plate to be processed to sequentially prepare a plurality of first target holes on the plate to be processed; performing a second drilling process on the plate to be processed to sequentially prepare a plurality of second target holes on the plate to be processed to prepare a printed circuit board; wherein the plurality of first target holes and the plurality of second target holes are arranged alternately one by one in sequence, so as to ensure that when the first drilling process is used to prepare the next adjacent first target hole, there is sufficient spacing between the two first target holes to reduce heat agglomeration during the preparation process, and to ensure that when the second drilling process is used to prepare the next adjacent second target hole, there is sufficient spacing between the two second target holes to reduce heat agglomeration during the preparation process. The second drilling process is performed after the first drilling process is completed, so that the processing time interval between adjacent target holes is greatly increased; the problem that the heat cannot be dissipated in time due to the short interval time in the same area can be effectively reduced, the heat agglomeration during the preparation process is further reduced, the delamination of the conductive layer and the dielectric layer due to heat is reduced, and the structural stability and reliability of the printed circuit board are improved.

[0037] In other embodiments, the target hole may also include a first target hole, a second target hole, and a third target hole. The first target hole, the second target hole, and the third target hole are arranged alternately in sequence and prepared in batches, that is, the first target hole is obtained by the first drilling process, the second target hole is obtained by the second drilling process, and the third target hole is obtained by the third drilling process, which further greatly increases the processing time interval and spacing distance between adjacent target holes to reduce heat accumulation during the preparation process.

[0038] In other embodiments, the target wells may also include multiple target wells prepared in batches, for example, 4, 5, 6, etc. The specific number is not limited here.

[0039] See also Figure 2 , Figure 2 The figure is a flow chart of another embodiment of the method for preparing a printed circuit board provided by the present invention.

[0040] Step S21: alternately stacking and pressing multiple conductive layers and multiple dielectric layers in sequence to obtain a plate to be processed.

[0041] The conductive layer includes but is not limited to a copper layer, an aluminum layer, a silver layer, a nickel layer, a gold layer or an alloy layer, and the copper layer includes a reverse treated copper foil (RTF) and a high velocity low profile copper foil (HVLP), both of which are applicable.

[0042] The dielectric layer includes but is not limited to one or more insulating materials such as prepreg, epoxy resin, polyester resin (PET), polyimide, polyimide, polycarbonate (PC), bismaleimide triazine (BT), Ajinomoto build film (ABF), FR4 resin, ceramic base, etc.

[0043] The plate to be processed is a process plate in the process of preparing a printed circuit board, such as a core board that has not been pressed, an intermediate plate after pressing a part of the conductive layer, and an integral plate after pressing. The specific selection of the plate to be processed is set based on actual needs. After each pressing, drilling can be performed according to the drilling method of this embodiment based on needs.

[0044] Step S22: performing a first drilling process on the plate to be processed by laser direct drilling technology to prepare a plurality of first target holes arranged at intervals on the plate to be processed.

[0045] Laser direct drilling technology is LDD (Laser Direct Drill) technology, which has high efficiency and precision.

[0046] First, the plate to be processed is subjected to a first drilling process, and all first target holes are prepared in sequence.

[0047] Step S23: performing a second drilling process on the plate to be processed by laser direct drilling technology to prepare a plurality of second target holes correspondingly around the plurality of first target holes.

[0048] The plate to be processed is subjected to a second drilling process to prepare all second target holes in sequence.

[0049] Among them, multiple first target holes and multiple second target holes are arranged alternately one by one, that is, when the first drilling process prepares the first target hole, a margin spacing for the subsequent preparation of the second target hole must be reserved between each two adjacent first target holes. When the second drilling process prepares the second target hole, a first target hole must be spaced between each two adjacent second target holes, so as to ensure that when the first drilling process prepares the next adjacent first target hole, there is enough spacing between the two first target holes to reduce heat agglomeration during the preparation process, and to ensure that when the second drilling process prepares the next adjacent second target hole, there is enough spacing between the two second target holes to reduce heat agglomeration during the preparation process. The second drilling process is carried out after the first drilling process is completed, so that the processing time interval between adjacent target holes is greatly increased; it can effectively avoid the problem that the heat in the same area cannot be dissipated in time due to too short an interval time, and further reduce heat agglomeration during the preparation process.

[0050] See also Figure 3 , Figure 3 It is a schematic diagram of the arrangement of the first target hole and the second target hole in one embodiment.

[0051] A plurality of first target holes 311 and a plurality of second target holes 312 are arranged in an array on the plate 30 to be processed to form a drilling area 31. There may be one or more drilling areas 31 on the plate 30 to be processed. In the horizontal x and vertical y directions of the plane where the drilling area 31 is located, the plurality of first target holes 311 and the plurality of second target holes 312 are alternately arranged one by one in sequence, so that a corresponding second target hole 312 is provided between each two adjacent first target holes 311, and a corresponding first target hole 311 is provided between each two adjacent second target holes 312.

[0052] The first target holes 311 are prepared in sequence in the drilling area 31 by the first drilling process, and the second target holes 312 are prepared in sequence in the drilling area 31 by the second drilling process after the preparation is completed. The processing time interval of adjacent target holes is increased by several dozen times, that is, the function of flying drilling processing is achieved, and at the same time, the problem of heat not being able to be dissipated in time due to too short interval time in the same drilling area 31 can be effectively avoided.

[0053] In a specific application scenario, the first target hole 311 and the second target hole 312 have the same aperture. The first target hole 311 and the second target hole 312 are distinguished by the front-end setting, so that the first drilling process and the second drilling process are separated and performed independently, thereby further ensuring the processing time interval between adjacent target holes, thereby reducing heat accumulation in the preparation process, reducing the delamination of the conductive layer and the dielectric layer due to heat, and improving the structural stability and reliability of the printed circuit board.

[0054] In another embodiment, the apertures of the first target hole and the second target hole may be different, so that the first drilling process and the second drilling process must be performed separately and independently, thereby further ensuring the processing time interval between adjacent target holes, thereby reducing heat accumulation during the preparation process, reducing the delamination of the conductive layer and the dielectric layer due to heat, and improving the structural stability and reliability of the printed circuit board.

[0055] See also Figure 4 , Figure 4 It is a schematic diagram of the arrangement of the first target hole and the second target hole in another embodiment.

[0056] A plurality of first target holes 411 and a plurality of second target holes 412 are arranged in an array on the plate 40 to be processed to form a drilling area 41 .

[0057] In the horizontal x and vertical y directions of the plane where the drilling area 41 is located, multiple first target holes 411 and multiple second target holes 412 are arranged alternately one by one in sequence, so that a corresponding second target hole 412 is arranged between every two adjacent first target holes 411, and a corresponding first target hole 411 is arranged between every two adjacent second target holes 412.

[0058] The first target holes 411 are prepared in sequence in the drilling area 41 by the first drilling process, and the second target holes 412 are prepared in sequence in the drilling area 41 by the second drilling process after the preparation. The processing time interval between adjacent target holes is increased by several dozen times, that is, the function of flying drilling is achieved, and at the same time, the problem of heat not being able to be dissipated in time due to too short interval time in the same drilling area 41 can be effectively avoided.

[0059] In a specific application scenario, the first target hole 411 and the second target hole 412 have different shapes, so that the first drilling process and the second drilling process must be performed separately and independently, thereby further ensuring the processing time interval between adjacent target holes, thereby reducing heat accumulation during the preparation process, reducing the delamination of the conductive layer and the dielectric layer due to heat, and improving the structural stability and reliability of the printed circuit board.

[0060] In other embodiments, the shapes and diameters of the first target holes 411 and the second target holes 412 may be different from each other, so that the first target holes 411 and the second target holes 412 must be prepared in batches.

[0061] Step S24: electroplating and etching are performed on the plate to be processed in sequence until a conductive circuit is prepared to obtain a printed circuit board.

[0062] After the drilling is completed, the plate to be processed is electroplated and etched in sequence so that the outer conductive layer forms a conductive circuit to obtain a printed circuit board.

[0063] Specifically, the plate to be processed is first electroplated to fill the target holes until reaching the outer conductive layer, and then the outer conductive layer is pattern-etched to form a conductive circuit.

[0064] The plate to be processed is then subjected to a heat treatment at a temperature greater than or equal to the glass transition temperature Tg of the dielectric layer of the plate to be processed.

[0065] Then, electronic components are welded on the board to be processed to obtain a printed circuit board.

[0066] In the above steps, after the pattern etching is completed, the board to be processed is baked at the Tg point, and the stress of the dielectric layer of the board to be processed is slowly released in advance and converted into a glass state, so as to avoid the problem of delamination of the conductive layer and the dielectric layer caused by the rapid temperature change during the reflow soldering process. The reliability and structural stability of the printed circuit board are further improved.

[0067] See also Figure 5 , Figure 5 It is a schematic structural diagram of an embodiment of a printed circuit board of the present invention.

[0068] The printed circuit board 51 includes a circuit board body 50 , on which a plurality of first target holes 511 and a plurality of second target holes 512 are formed, wherein the plurality of first target holes 511 and the plurality of second target holes 512 are alternately arranged one by one.

[0069] The printed circuit board 51 is prepared by the method for preparing a printed circuit board of any of the above embodiments. It is possible to ensure that there is a sufficient preparation interval between the two target holes to reduce heat accumulation during the preparation process, reduce the delamination of the conductive layer and the dielectric layer due to heat, and improve the structural stability and reliability of the printed circuit board.

[0070] In other embodiments, the first target hole 511 and the second target hole 512 have the same aperture and / or shape, and are distinguished from each other by a front-end setting, so that the first target hole 511 and the second target hole 512 must be processed independently during the preparation process, thereby further ensuring the processing time interval between adjacent target holes, thereby reducing heat accumulation during the preparation process, reducing the delamination of the conductive layer and the dielectric layer due to heat, and improving the structural stability and reliability of the printed circuit board.

[0071] In other embodiments, a third target hole 513 is formed on the circuit board body 50, and a plurality of first target holes 511, a plurality of second target holes 512 and a plurality of third target holes 513 are arranged alternately in sequence, and the apertures and / or shapes of the first target holes 511, the second target holes 512 and the third target holes 513 are the same. The first target holes 511, the second target holes 512 and the third target holes 513 are distinguished by the front end setting, thereby further ensuring the processing time interval between adjacent target holes, thereby reducing heat agglomeration during the preparation process, reducing the delamination of the conductive layer and the dielectric layer due to heat, and improving the structural stability and reliability of the printed circuit board.

[0072] In other embodiments, the apertures and / or shapes of the first target hole 511, the second target hole 512, and the third target hole 513 may all be different or partially different, so that the first target hole 511, the second target hole 512, and the third target hole 513 must be processed independently during the preparation process, thereby further ensuring the processing time interval between adjacent target holes, thereby reducing heat accumulation during the preparation process, reducing the delamination of the conductive layer and the dielectric layer due to heat, and improving the structural stability and reliability of the printed circuit board 51.

[0073] In other embodiments, the target wells may also include multiple target wells prepared in batches, for example, 4, 5, 6, etc. The specific number is not limited here.

[0074] The above description is only an implementation mode of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A method for preparing a printed circuit board, characterized in that: The method for preparing the printed circuit board comprises: Obtain the plate to be processed; Performing a first drilling process on the plate to be processed, so as to sequentially prepare a plurality of first target holes on the plate to be processed; Performing a second drilling process on the plate to be processed, and sequentially preparing a plurality of second target holes on the plate to be processed to prepare a printed circuit board; Wherein, the plurality of the first target holes and the plurality of the second target holes are arranged alternately one by one.

2. The method for preparing a printed circuit board according to claim 1, characterized in that: A plurality of the first target holes and a plurality of the second target holes are arranged in an array to form a drilling area; In the horizontal and vertical directions of the plane where the drilling area is located, multiple first target holes and multiple second target holes are arranged alternately one by one in sequence, so that a corresponding second target hole is set between every two adjacent first target holes, and a corresponding first target hole is set between every two adjacent second target holes.

3. The method for preparing a printed circuit board according to claim 1 or 2, characterized in that: The first target hole and the second target hole have the same aperture and / or shape; Before the step of acquiring the plate to be processed, the method includes: distinguishing the first target hole from the second target hole through front-end setting.

4. The method for preparing a printed circuit board according to claim 1, characterized in that: The step of performing a second drilling process on the plate to be processed and sequentially preparing a plurality of second target holes on the plate to be processed comprises: Performing a third drilling process on the plate to be processed, and sequentially preparing a plurality of third target holes on the plate to be processed; The plurality of first target holes, the plurality of second target holes and the plurality of third target holes are alternately arranged one by one.

5. The method for preparing a printed circuit board according to claim 1, characterized in that: The step of performing a first drilling process on the plate to be processed to sequentially prepare a plurality of first target holes on the plate to be processed comprises: Performing a first drilling process on the plate to be processed by laser direct drilling technology to prepare a plurality of first target holes arranged at intervals on the plate to be processed; The step of performing a second drilling process on the plate to be processed to sequentially prepare a plurality of second target holes on the plate to be processed to prepare a printed circuit board comprises: The plate to be processed is subjected to a second drilling process by laser direct drilling technology, so as to prepare a plurality of second target holes correspondingly around the plurality of first target holes, so as to prepare a printed circuit board.

6. The method for preparing a printed circuit board according to claim 1, characterized in that: The step of obtaining the plate to be processed comprises: Alternately stacking and pressing multiple conductive layers and multiple dielectric layers in sequence to obtain the plate to be processed; The step of performing a second drilling process on the plate to be processed to sequentially prepare a plurality of second target holes on the plate to be processed to prepare a printed circuit board also includes: The plate to be processed is electroplated and etched in sequence until a conductive circuit is prepared to obtain the printed circuit board.

7. The method for preparing a printed circuit board according to claim 6, characterized in that: The step of sequentially electroplating and etching the plate to be processed to form a conductive circuit to obtain the printed circuit board includes: Electroplating and pattern etching are sequentially performed on the plate to be processed to prepare a conductive circuit; Performing heat treatment on the plate to be processed; Electronic components are welded on the plate to be processed to obtain the printed circuit board.

8. The method for preparing a printed circuit board according to claim 7, characterized in that: The temperature of the heat treatment is greater than or equal to the glass transition temperature of the dielectric layer of the plate to be processed.

9. A printed circuit board, characterized in that: The printed circuit board is prepared by the method for preparing a printed circuit board according to any one of claims 1 to 8, comprising: A circuit board body is formed with a plurality of first target holes and a plurality of second target holes, wherein the plurality of first target holes and the plurality of second target holes are alternately arranged one by one.

10. The printed circuit board according to claim 9, characterized in that: A third target hole is formed on the circuit board body, and a plurality of the first target holes, a plurality of the second target holes and a plurality of the third target holes are alternately arranged one by one, and the apertures and / or shapes of the first target holes, the second target holes and the third target holes are the same.

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