阅读说明：本技术 印制电路板pcb及其制备方法 (Printed Circuit Board (PCB) and preparation method thereof ) 是由 黄明利 陶士超 于 2021-09-18 设计创作，主要内容包括：本申请提供了一种印制电路板PCB及其制备方法,能够应用在手机、电脑、基站天线等通信装置中。其中,该PCB包括：第一子板、设置于第一子板下方的第二子板、第一塞孔、第二塞孔和塞孔胶层；其中,第一塞孔贯穿于第一子板的上下表面,第二塞孔贯穿于第二子板的上下表面,第一塞孔和第二塞孔包括塞孔胶；塞孔胶层位于第一子板的下表面和第二子板的上表面之间；第一塞孔和第二塞孔的塞孔胶与塞孔胶层呈一体结构。本申请方案所提供的PCB中的第一塞孔和第二塞孔的塞孔胶与塞孔胶层呈一体结构,从而能够提升PCB的机械性能。(The application provides a Printed Circuit Board (PCB) and a preparation method thereof, which can be applied to communication devices such as mobile phones, computers, base station antennas and the like. Wherein, this PCB includes: the plug structure comprises a first sub-board, a second sub-board arranged below the first sub-board, a first plug hole, a second plug hole and a plug hole glue layer; the first plug hole penetrates through the upper surface and the lower surface of the first sub-board, the second plug hole penetrates through the upper surface and the lower surface of the second sub-board, and the first plug hole and the second plug hole comprise plug hole glue; the plug hole glue layer is positioned between the lower surface of the first sub-board and the upper surface of the second sub-board; the plug hole glue and the plug hole glue layer of the first plug hole and the second plug hole are of an integrated structure. The first consent in the PCB that this application scheme provided glues and is an organic whole structure with the consent glue film of second consent to can promote PCB's mechanical properties.)

1. A printed circuit board, PCB, comprising: the plug comprises a first sub-board, a second sub-board arranged below the first sub-board, a first plug hole, a second plug hole and a plug hole glue layer;

the first plug hole penetrates through the upper surface and the lower surface of the first sub-board, the second plug hole penetrates through the upper surface and the lower surface of the second sub-board, and the first plug hole and the second plug hole comprise plug hole glue; the plug hole glue layer is positioned between the lower surface of the first sub-board and the upper surface of the second sub-board; the plug hole glue of the first plug hole and the second plug hole and the plug hole glue layer are of an integrated structure.

2. The PCB of claim 1, wherein there is no interface between the receptacle glue layer and the first receptacle or the second receptacle.

3. The PCB of claim 1 or 2, wherein the thickness of the layer of plug glue is 0.1mm-0.3 mm.

4. The PCB of any one of claims 1 to 3, wherein the plug glue layer comprises a chopped fiber prepreg, the chopped fiber prepreg has a glue content of greater than or equal to 80%, and the chopped fibers have a length of 0.1mm to 15mm and a diameter of 0.005mm to 0.05 mm.

5. The PCB of any one of claims 1 to 3, wherein the plug glue layer comprises a glue film, and the glue content of the glue film is 95% -100%.

6. The PCB of any one of claims 1 to 5, wherein the thickness of the first receptacle and/or the second receptacle is 0.2mm-2.5 mm.

7. The PCB of any one of claims 1 to 6, wherein the bore diameter of the first receptacle and/or the second receptacle is 0.1mm-0.25 mm.

8. A method for preparing a Printed Circuit Board (PCB), wherein the PCB comprises a first sub-board and a second sub-board arranged below the first sub-board, the method comprising:

drilling the first sub-board to form a first hole to be plugged penetrating through the upper surface and the lower surface of the first sub-board;

arranging a conductive layer on the side wall of the first hole to be plugged;

drilling the second sub-board to form a second hole to be plugged penetrating through the upper surface and the lower surface of the second sub-board;

arranging a conductive layer on the side wall of the second hole to be plugged;

a plug hole glue layer is arranged between the lower surface of the first sub-board and the upper surface of the second sub-board;

and pressing the plug hole adhesive layer to enable the plug hole adhesive layer to flow and fill the first plug hole to be plugged and the second plug hole to be plugged to obtain the PCB.

9. The method for preparing the membrane according to claim 8, wherein the thickness of the pore plugging glue layer is 0.1mm-0.3 mm.

10. The preparation method according to claim 8 or 9, wherein the plug glue layer comprises a chopped fiber prepreg, the content of glue in the chopped fiber prepreg is greater than or equal to 80%, the length of the chopped fiber is 0.1mm-15mm, and the diameter of the chopped fiber is 0.005mm-0.05 mm.

11. The preparation method according to claim 8 or 9, wherein the plug glue layer comprises a glue film, and the glue content of the glue film is 95% -100%.

12. The method for preparing according to any one of claims 8 to 11, wherein the thickness of the first hole to be plugged and/or the second hole to be plugged is 0.2mm to 2.5 mm.

13. The method for preparing according to any one of claims 8 to 12, wherein the diameter of the bore of the first hole to be plugged and/or the second hole to be plugged is 0.1mm-0.25 mm.

14. The manufacturing method according to any one of claims 8 to 13, wherein a release film is laid on an outer side of the PCB when laminating.

15. An electronic device comprising the PCB of any one of claims 1 to 7.

Technical Field

The present application relates to the field of printed circuit board technology, and more particularly, to a PCB and a method of manufacturing the same.

Background

The integrated design of Printed Circuit Boards (PCBs) with different functions, such as an antenna PCB and a transceiver unit (carrier frequency, TRX) PCB, can effectively reduce the assembly complexity, increase the integration density, reduce the volume, and reduce the transmission loss. Generally, in the implementation process, daughter boards carrying different functions need to be prepared respectively, and then a plurality of daughter boards are mixed and pressed to implement an integrated design. However, the conventional solution involves resin via hole plugging, board grinding, and via hole Automatic Optical Inspection (AOI) operations when manufacturing a plurality of daughter boards, respectively, resulting in poor mechanical properties of the finally manufactured PCB.

Therefore, how to improve the mechanical performance of the PCB is a technical problem that needs to be solved urgently.

Disclosure of Invention

The application provides a PCB and a preparation method thereof, which can improve the mechanical property of the PCB.

In a first aspect, there is provided a printed circuit board, PCB, comprising: the plug comprises a first sub-board, a second sub-board arranged below the first sub-board, a first plug hole, a second plug hole and a plug hole glue layer; the first plug hole penetrates through the upper surface and the lower surface of the first sub-board, the second plug hole penetrates through the upper surface and the lower surface of the second sub-board, and the first plug hole and the second plug hole comprise plug hole glue; the plug hole glue layer is positioned between the lower surface of the first sub-board and the upper surface of the second sub-board; the plug hole glue of the first plug hole and the second plug hole and the plug hole glue layer are in an integral structure.

It should be understood that in the design of unifying of a plurality of traditional daughter boards, can involve resin consent, grind board, operation such as consent automatic optical detection respectively when preparing a plurality of daughter boards, lead to finally exist the interface between the glue film between the consent and the daughter board of a plurality of daughter boards in the PCB who prepares, lead to easily take place layering fracture under the effect of stress between a plurality of daughter boards of PCB to lead to PCB's mechanical properties relatively poor.

The first plug hole and the second plug hole in the PCB are integrally formed in the plug hole glue layer and the plug hole glue layer, layered cracking between the sub-boards under the action of stress can be avoided, and therefore mechanical performance of the PCB can be improved.

With reference to the first aspect, in certain implementations of the first aspect, there is no interface between the plug hole paste layer and the first plug hole or the second plug hole.

It should be understood that, in the present application, the plug hole paste of the first plug hole and the second plug hole is formed by pressing the plug hole paste layer to flow the paste under high temperature and high pressure and filling the first plug hole and the second plug hole, so that there is no interface between the first plug hole or the second plug hole and the plug hole paste layer, thereby being capable of improving the mechanical performance of the PCB.

With reference to the first aspect, in certain implementations of the first aspect, the thickness of the plug gel layer is 0.1mm to 0.3 mm.

With reference to the first aspect, in certain implementations of the first aspect, the plug gum layer includes a chopped strand prepreg having a gum content of greater than or equal to 80%, the chopped strand having a length of 0.1mm to 15mm and a diameter of 0.005mm to 0.05 mm.

With reference to the first aspect, in certain implementations of the first aspect, the plug hole glue layer includes a glue film, and a glue content of the glue film is 95% to 100%.

With reference to the first aspect, in certain implementations of the first aspect, the thickness of the first receptacle and/or the second receptacle is 0.2mm to 2.5 mm.

With reference to the first aspect, in certain implementations of the first aspect, the first receptacle and/or the second receptacle have a bore diameter of 0.1mm to 0.25 mm.

With reference to the first aspect, in some implementations of the first aspect, the first sub-board is an antenna PCB, and the second sub-board is a carrier frequency PCB.

Optionally, the antenna PCB is a double-layer board, and the carrier PCB is a multilayer board.

It should be understood that in a unified design of the antenna PCB and the carrier PCB, the antenna PCB may also be referred to as an antenna daughter board, and the carrier PCB may also be referred to as a carrier daughter board.

With reference to the first aspect, in certain implementations of the first aspect, the outside of the PCB is covered with a release film when press-fitting.

With reference to the first aspect, in certain implementations of the first aspect, the conductive layer is a metal conductive layer.

In a second aspect, there is provided a method of manufacturing a printed circuit board PCB including a first sub-board and a second sub-board disposed under the first sub-board, the method including: drilling the first daughter board to form a first hole to be plugged penetrating through the upper surface and the lower surface of the first daughter board; arranging a conductive layer on the side wall of the first hole to be plugged; drilling the second daughter board to form a second hole to be plugged penetrating through the upper surface and the lower surface of the second daughter board; arranging a conductive layer on the side wall of the second hole to be plugged; a plug glue layer is arranged between the lower surface of the first sub-board and the upper surface of the second sub-board; and pressing the plug hole adhesive layer to flow and fill the first plug hole to be plugged and the second plug hole to be plugged to obtain the PCB.

It should be understood that in the conventional processing process flow, when a plurality of daughter boards are subjected to unified design, each daughter board involves operations such as resin plug hole, board grinding, plug hole AOI and the like, so that the complexity of the whole preparation flow is high; meanwhile, grinding after resin hole plugging can also cause the expansion and contraction coefficient of the daughter board to change, so that matching is difficult, and the layer offset control is not favorable.

In this application embodiment, make the consent glue film flow the hand-hole and then realize the consent of each daughter board through the pressfitting for need not to carry out resin consent, grind board, consent AOI etc. operation respectively to every daughter board in the preparation process, thereby can reduce the complexity of whole preparation flow, reduce cost, improve the yield and reduce the degree of difficulty of daughter board harmomegathus coefficient control.

With reference to the second aspect, in certain implementations of the second aspect, the thickness of the plug gel layer is 0.1mm to 0.3 mm.

With reference to the second aspect, in certain implementations of the second aspect, the plug bond line includes a chopped strand prepreg having a gel content of greater than or equal to 80%, the chopped strand having a length of 0.1mm to 15mm and a diameter of 0.005mm to 0.05 mm.

In the embodiment of the application, the plug hole glue layer comprises the chopped fiber prepreg, and the length and the glue content of the chopped fiber are in a proper range, so that the finally obtained plug holes are full and have no problems of poor plug holes and the like.

With reference to the second aspect, in certain implementations of the second aspect, the plug hole glue layer includes a glue film, and a glue content of the glue film is 95% to 100%.

It should be understood that when the glue content of the glue film is 100%, the glue film can also be referred to as a pure glue film.

In the embodiment of the application, the plug hole glue layer comprises a glue film, and the glue content of the glue film is 95% -100%, so that the finally obtained plug holes are full and have no problems of poor plug holes and the like.

With reference to the second aspect, in certain implementations of the second aspect, the thickness of the first hole to be plugged and/or the second hole to be plugged is 0.2mm-2.5 mm.

With reference to the second aspect, in certain implementations of the second aspect, the bore diameter of the first hole to be plugged and/or the second hole to be plugged is 0.1mm-0.25 mm.

This application is through the design of above-mentioned consent glue film for to thickness or the great consent of treating of thickness, also can reach excellent filling effect.

With reference to the second aspect, in some implementations of the second aspect, the first sub-board is an antenna PCB, and the second sub-board is a carrier frequency PCB.

Optionally, the antenna PCB is a double-layer board, and the carrier PCB is a multilayer board.

It should be understood that in a unified design of the antenna PCB and the carrier PCB, the antenna PCB may also be referred to as an antenna daughter board, and the carrier PCB may also be referred to as a carrier daughter board.

With reference to the second aspect, in certain implementations of the second aspect, a release film is laid on the outer side of the PCB during the press-fitting.

Optionally, other buffer materials may be also laid on the outer side of the PCB for blocking glue, which is not limited.

Optionally, the surface oxidation and the running glue can be treated by adopting a sand belt or ceramic grinding mode after the pressing.

With reference to the second aspect, in certain implementations of the second aspect, the conductive layer is a metal conductive layer.

In a third aspect, an electronic device is provided, which comprises a PCB as in the first aspect or any possible implementation manner of the first aspect.

Alternatively, the electronic device may be a communication device such as a mobile phone, a computer, a base station antenna, and the like.

Drawings

Fig. 1 is a flow chart of a conventional processing scheme.

Fig. 2 is an exemplary diagram of a method for manufacturing a PCB according to an embodiment of the present disclosure.

Fig. 3 is a flow chart of a processing process provided in an embodiment of the present application.

Fig. 4 is a diagram illustrating a structure of a PCB 400 according to an embodiment of the present disclosure.

Fig. 5 is a diagram illustrating an example of a PCB structure laminated with chopped strand prepreg according to an embodiment of the present disclosure.

Fig. 6 is an exemplary diagram of a PCB structure laminated with a pure glue film according to an embodiment of the present disclosure.

Fig. 7 is a diagram illustrating another structure of a PCB 700 according to an embodiment of the present disclosure.

Fig. 8 is a diagram illustrating a thick copper gap structure filling of a PCB according to an embodiment of the present disclosure.

Detailed Description

First, referring to fig. 1, a process flow of a conventional solution will be described by taking an integrated design of an antenna PCB (i.e., a first daughter board) and a TRX PCB (i.e., a second daughter board) as an example. As shown in fig. 1, the conventional processing flow is as follows:

first daughter board flow (taking a double-layer board as an example): feeding → drilling → copper deposition/electroplating → resin plug hole → grinding plate/plug hole AOI → daughter board pattern → mother board transfer flow.

Second daughter board flow (example multilayer board): feeding → inner layer pattern → punching → matching → pressing → drilling → copper deposition/electroplating → resin plug hole → grinding plate/plug hole AOI → outer layer pattern of sub-plate → tool hole making → mother plate transfer process.

Mother board flow: matching the first sub-board and the second sub-board → pressing → drilling → copper deposition/electroplating → outer layer pattern → following PCB routine flow.

Wherein, the incoming materials: the method is a process for cutting an original copper-clad plate into plates which can be manufactured on a production line.

Copper-clad plate: the electronic glass fiber cloth or other reinforced materials are soaked in resin glue solution to prepare glue soaking material (also called prepreg (PP)), one side or two sides of the glue soaking material are covered with copper foil (hereinafter called copper layer), and the plate-shaped material is formed by hot pressing, and is called Copper Clad Laminate (CCL), copper clad laminate for short, and base material (plate). When it is used in the production of multilayer boards, it is also called a core board (core). The core board without copper foil on both sides is also called a light board. It should be understood that the lamination material of the multi-layer board is mainly PP and core.

Drilling: so that through holes are formed between the layers of the circuit board, and the purpose of communicating the layers is achieved.

Copper deposition/electroplating: so that the metal conductive layer is attached to the surface of the original insulated substrate to achieve the electrical communication between layers.

Grinding a plate: the burr on the orifice is removed, the dirt on the plate and the dust in the hole are cleaned, and a clean surface is provided for the subsequent copper deposition layer or the electroplated layer to be well attached to the plate surface and in the hole.

Hole plugging AOI: and comparing the plug holes by using an optical principle to accurately detect the defect points.

And (3) laminating: the respective substrates were bonded together by fusing the PP sheets at high temperature and high pressure.

And (3) pattern: specifically, a pattern resist layer is formed on the copper layer, and then an excess copper foil is removed by etching to form a pattern.

In the traditional processing process flow, when a plurality of daughter boards are designed in a unified way, each daughter board can involve the operations of resin plug hole, board grinding, plug hole AOI and the like, so that the complexity of the whole preparation flow is higher; meanwhile, grinding after resin hole plugging can also cause the expansion and contraction coefficient of the daughter board to change, so that matching is difficult, and the layer offset control is not favorable.

In order to avoid the above problems, embodiments of the present application provide a method for manufacturing a PCB, which allows a plug hole glue layer to flow into a hole at high temperature and high pressure by pressing a mother board, thereby realizing plug hole of each daughter board. The scheme of the application can reduce the complexity of the whole preparation process, and can avoid other problems caused by grinding the daughter board.

The embodiments of the present application will be described in detail below with reference to the accompanying drawings.

Fig. 2 is an exemplary diagram of a method for manufacturing a PCB according to an embodiment of the present disclosure. It should be understood that the PCB includes a first sub-board and a second sub-board disposed below the first sub-board. As shown in fig. 2, the preparation method 200 includes steps S210 to S260. It should be understood that, the sequence of the above steps is not limited in the embodiment of the present application, and all solutions that can implement the present application through any sequence of the above steps fall within the protection scope of the present application. These steps are described in detail below.

S210, drilling the first sub-board to form a first to-be-plugged hole penetrating through the upper surface and the lower surface of the first sub-board.

S220, arranging a conductive layer on the side wall of the first hole to be plugged.

And S230, drilling the second sub-board to form a second hole to be plugged penetrating through the upper surface and the lower surface of the second sub-board.

And S240, arranging a conductive layer on the side wall of the second hole to be plugged.

It should be understood that the first sub-board and the second sub-board may be sub-boards carrying different functions, respectively.

Optionally, the first sub-board may be an antenna PCB, and the antenna PCB may be a copper-clad board prepared based on a radio frequency material, or a copper-clad board prepared based on other materials, which is not limited in the present application.

Optionally, the second daughter board may be a carrier PCB, and the carrier daughter board may be a copper clad board prepared based on FR (e.g., FR4 grade) materials of different grades, which is not limited in this application.

It should be understood that, in the integrated design of the antenna PCB and the carrier frequency PCB, the antenna PCB may also be referred to as an antenna daughter board, and the carrier frequency PCB may also be referred to as a carrier frequency daughter board, which is not limited in this application.

Alternatively, the antenna PCB may be a dual layer board (i.e., including a dual layer copper layer) and the carrier PCB may be a multi-layer board (i.e., including a multi-layer copper layer), which is not limited in this application.

It should be understood that the conductive layer serves to allow electrical communication between the copper layers. Alternatively, the conductive layer may be a metal conductive layer, and the metal conductive layer may be implemented by copper deposition or electroplating.

Optionally, the method 200 may further include: inner layer patterns and outer layer patterns in the daughter board are prepared.

And S250, arranging a plug glue layer between the lower surface of the first sub-board and the upper surface of the second sub-board.

It should be understood that the first sub-board and the second sub-board can be pressed and bonded through the plug glue layer to form the mother board. In addition, the plug hole glue layer can be changed into a flowable liquid substance in a high-temperature, high-pressure and vacuum environment, and in this state, the plug holes to be plugged of the first sub-plate and the second sub-plate can be fully filled with the liquid flow glue.

Alternatively, the thickness of the first hole to be plugged and/or the second hole to be plugged may be 0.2mm-2.5 mm.

Alternatively, the bore diameter of the first hole to be plugged and/or the second hole to be plugged may be 0.1mm-0.25 mm.

Optionally, the thickness of the plug hole glue layer is 0.1mm-0.3 mm.

Alternatively, the plug gum layer may include a chopped strand prepreg, which may have a gum content of greater than or equal to 80%, and the chopped strand may have a length of 0.1mm to 15mm and a diameter of 0.005mm to 0.05 mm. Alternatively, SP175M chopped fiber prepreg may be used in practice, which is not limited in this application. Optionally, the plug glue layer may be a single chopped fiber prepreg having a thickness that meets the requirements, or a plurality of plugs may be stacked, as long as the finally formed plug glue layer can achieve good plug.

Optionally, the plug hole glue layer may include a glue film, and the glue content of the glue film is 95% -100%. It should be understood that when the glue content of the glue film is 100%, the glue film can also be referred to as a pure glue film. This pure glued membrane also can be called as and does not have the reinforcing material glued membrane, and as above, can select for use the sola glued membrane in actual operation, also can select for use many glued membranes to stack, and this application does not do the restriction to this. For example, 2 sheets of plastic film can be selected to form the plug hole glue layer, and the thickness of each sheet of plastic film can be 120 um.

It should be understood that the holes to be plugged in the daughter boards generally have a high aspect ratio, so in practical operation, the holes need to be plugged with resin ink respectively for different daughter boards, and then operations such as grinding the board, plugging the holes AOI, etc. are performed, thereby resulting in complexity of the process. According to the technical scheme, the hole to be plugged with the high thickness-diameter ratio is filled in the process of pressing the mother board through the design, so that the processing technology is simplified, and the cost is reduced.

S260, pressing the plug hole glue layer to flow and fill the first plug hole and the second plug hole to obtain the PCB, and referring to fig. 4 for a comparative example of the structure before and after pressing.

It should be understood that, during the lamination, a buffer material such as a release film needs to be laid on the outer side of the PCB for blocking glue.

Optionally, the surface oxidation and the running glue can be treated by adopting a sand belt or ceramic grinding mode after the pressing.

Optionally, the pressfitting row board design can be: bottom steel plate-kraft paper-aluminum sheet-release film-matched operation plate-release film-aluminum sheet-kraft paper-low steel plate (or mirror surface steel plate). It is to be understood that, among other things, the work board is a sheet material to be laminated.

It should be understood that, in actual practice, the PCB may include more daughter boards besides the first daughter board and the second daughter board, a plug glue layer may be disposed between any two daughter boards of the more daughter boards to flow and fill the through holes in the corresponding daughter boards during the pressing process, and each daughter board may be a single-layer board or a multi-layer board, as described in fig. 7.

It should be understood that, in practical operation, the hole of one daughter board may be filled only by the plug glue layer, which is not limited in this application.

It should be understood that, for a multilayer board, a plug glue layer may also be disposed between any two core boards, so that during the pressing process, filling of the pattern gaps of copper layers (especially thick copper) in the multilayer board is realized, as described in fig. 8.

The following also takes the design of combining the antenna PCB (i.e. the first sub-board) and the TRX PCB (i.e. the second sub-board) as an example to describe a specific processing process flow of the present application. As shown in fig. 3, the processing process flow of the scheme of the application is as follows:

first daughter board flow (taking a double-layer board as an example): feeding → drilling → copper deposition/electroplating → daughter board pattern → mother board transfer flow.

Second daughter board flow (example multilayer board): feeding → inner layer pattern → punching → matching → pressing → drilling → copper deposition/electroplating → sub-board outer layer pattern → tool hole making → mother board transfer flow.

Mother board flow: the first sub-board and the second sub-board are matched → pressed → grinded → drilled → copper deposition/electroplating → outer layer pattern → follow-up PCB normal flow.

Obviously, compared with the conventional daughter board process, the daughter board processes have no plug hole and related processes, thereby reducing the complexity of the preparation process.

Fig. 4 is a diagram illustrating a structure of a PCB 400 according to an embodiment of the present disclosure. Fig. 4 (a) is an exemplary diagram of a PCB structure before mother board bonding, and fig. 4 (b) is an exemplary diagram of a PCB structure after mother board bonding. It should be understood that the daughter board structure design in fig. 4 is by way of example only and is not limiting of the present application.

As shown in fig. 4 (b), the PCB 400 includes a first sub-board 10, a second sub-board 20 disposed under the first sub-board 10, a first tap hole 12, a second tap hole 23, and a tap glue layer 30.

The first plug hole 12 penetrates through the upper surface and the lower surface of the first sub-board 10, the second plug hole 23 penetrates through the upper surface and the lower surface of the second sub-board 20, and the first plug hole 12 and the second plug hole 23 comprise plug hole glue; the plug glue layer 30 is positioned between the lower surface of the first sub-board 10 and the upper surface of the second sub-board 20; the plug hole glue of the first plug hole 12 and the second plug hole 23 and the plug hole glue layer 30 are in an integral structure.

It should be understood that, in the present application, the plug hole paste of the first plug hole 12 and the second plug hole 23 is formed by pressing the plug hole paste layer 30 to flow paste under high temperature and high pressure and filling the first plug hole 12 and the second plug hole 23, that is, the first plug hole 12 and the second plug hole 23 are filled with the flow paste of the plug hole paste layer 30 in the pressing process, so that no interface exists between the first plug hole 12 or the second plug hole 23 and the plug hole paste layer 30, thereby preventing the PCB from delaminating and cracking under the stress effect, and further improving the mechanical performance of the PCB.

It should be understood that the receptacles are typically formed by filling the vias with a receptacle paste. In the application, a conductive layer 13 is further arranged between the inner wall of the via hole of the first plug hole 12 and the plug hole glue filling the via hole; a conductive layer 24 is further disposed between the inner wall of the via hole of the second plug hole 23 and the plug hole paste filling the via hole.

Wherein there is no interface between the plug hole glue layer 30 and the first plug hole 12 or the second plug hole 23.

Alternatively, the thickness of the make coat 30 may be 0.1mm to 0.3 mm.

Alternatively, the make coat 30 may include a chopped strand prepreg, which may have a gel content of greater than or equal to 80%, and chopped strands may have a length of 0.1mm to 15mm and a diameter of 0.005mm to 0.05mm, among others as described above.

Alternatively, the hole plugging glue layer 30 may include a glue film having a glue content of 95% -100%. Likewise, others may be referred to as described above.

Alternatively, the thickness of the first receptacle 12 and/or the second receptacle 23 may be 0.2mm to 2.5 mm.

Alternatively, the bore diameter of the first receptacle 12 and/or the second receptacle 23 may be 0.1mm to 0.25 mm.

Optionally, the first sub-board 10 may be an antenna PCB, and the first sub-board 10 may be a copper-clad board prepared based on the radio frequency material 11 (or other materials), which is not limited in this application.

Alternatively, the first sub-board 10 may be a double-layer board, i.e. may comprise a double-layer copper layer 40 (L1-L2). It should be understood that the number of copper layers of the first sub-board 10 shown in fig. 4 is only an example and is not limited.

Alternatively, the second sub-board 20 may be a carrier PCB, and the second sub-board 20 may be a multi-layer board formed by alternately laminating and stitching the core21 and the PP 22.

Optionally, the second sub-board 20 may include a copper layer 40 (L3-L8). It should be understood that the number of copper layers of the second sub-board 20 shown in fig. 4 is also merely an example and is not limited.

It should be understood that the core21 can be copper clad laminate made of different grades of FR (e.g., FR4 grade) material, which is not limited in this application.

Optionally, a buffer material such as a release film may be coated on the outer side of the PCB 400 for blocking glue (not shown) during the pressing process.

Optionally, conductive layers 13 and 24 are used to allow electrical communication between copper layers 40. Alternatively, the conductive layers 13 and 24 may be metal conductive layers, and the metal conductive layers may be formed by copper deposition or electroplating.

Optionally, the PCB 400 may further include a motherboard through hole 50 and a conductive layer 51 on an inner wall of the motherboard through hole 50, which is not described in detail herein.

Fig. 5 is an exemplary diagram of a PCB structure laminated with a chopped fiber prepreg according to an embodiment of the present disclosure, and fig. 6 is an exemplary diagram of a PCB structure laminated with a pure glue film according to an embodiment of the present disclosure. Obviously, the hole plugging is carried out through the pressing glue flowing in the scheme, so that the hole plugging is full, the problems of poor hole plugging and the like are solved.

In practical applications, the PCB may further include more daughter boards besides the first daughter board and the second daughter board, and a plug glue layer may be disposed between any two daughter boards of the more daughter boards. The following description will take the example where the PCB includes three daughter boards.

Exemplarily, fig. 7 is a diagram of another structure example of a PCB 700 provided in an embodiment of the present application. Fig. 7 (a) is an exemplary diagram of a PCB structure before bonding, and fig. 7 (b) is an exemplary diagram of a PCB structure after bonding. In this example, the PCB 700 includes three daughter boards.

As shown in fig. 7 (b), the PCB 700 includes a first sub-board 71, a second sub-board 72 disposed below the first sub-board 71, and a third sub-board 73 disposed below the second sub-board 72.

The first sub-board 71 includes a first plug hole 711, and the first plug hole 711 penetrates through the upper and lower surfaces of the first sub-board 71; the second sub-board 72 includes a second plug hole 721, and the second plug hole 721 penetrates through the upper and lower surfaces of the second sub-board 72; the third sub-plate 73 includes a third tap hole 731, and the third tap hole 731 penetrates through the upper and lower surfaces of the third sub-plate 73; the first to third tap holes 711, 721 and 731 include tap glue.

It should be understood that the receptacles are typically formed by filling the vias with a receptacle paste. In the present application, a conductive layer 712 is further disposed between the inner wall of the via hole of the first plug hole 711 and the plug hole paste filling the via hole; a conductive layer 722 is also arranged between the inner wall of the via hole of the second plug hole 721 and the plug hole glue filling the via hole; a conductive layer 732 is further disposed between the inner wall of the via hole of the third plug hole 731 and the plug glue filling the via hole.

Moreover, a plug glue layer 74 is arranged between the lower surface of the first sub-board 71 and the upper surface of the second sub-board 72, a plug glue layer 75 is arranged between the lower surface of the second sub-board 72 and the upper surface of the third sub-board 73, and the plug glue of the first plug hole 711, the second plug hole 721 and the second plug hole 731, the plug glue layer 74 and the plug glue layer 75 are of an integral structure.

Likewise, there is no interface between the plug hole glue layer and the plug hole. It should be understood that, in the present application, the plug hole glue of the first plug hole 711, the second plug hole 721 and the second plug hole 731 is formed by pressing the plug hole glue layer 74 and the plug hole glue layer 75 to flow glue under high temperature and high pressure and filling the first plug hole 711, the second plug hole 721 and the second plug hole 731, that is, the first plug hole 711, the second plug hole 721 and the second plug hole 731 are filled with the flow glue of the plug hole glue layer 74 and the plug hole glue layer 75 in the pressing process, so that no interface exists between the plug holes and the plug hole glue layer, thereby preventing the PCB from being delaminated and cracked under the stress action, and further improving the mechanical performance of the PCB.

Alternatively, in actual operation, each of the first sub-board 71, the second sub-board 72, and the third sub-board 73 may be either a single-layer board or a multi-layer board; the first sub-board 71, the second sub-board 72 and the third sub-board 73 can be made of the same material or different thicknesses; the materials and thicknesses of the plug glue layers 74 and 75 may be the same or different, and are not limited in this application.

Further, for a PCB including more daughter boards, each corresponding daughter board may be a single-layer board or a multi-layer board; the preparation material and the thickness of each sub-board can be the same or different; the glue layer material and thickness used by each plug hole glue layer can be the same or different, and the application does not limit the material and thickness.

In addition, as mentioned above, for the multilayer board, a plug glue layer may also be disposed between any two core boards, so that in the pressing process, the filling of the pattern gap of the copper layer (especially thick copper, that is, the thickness of the copper layer is greater than or equal to 2OZ) in the multilayer board is achieved. The filling of the thick copper gap is exemplarily described below with reference to fig. 8.

Fig. 8 is a diagram illustrating a thick copper gap structure filling of a PCB 800 according to an embodiment of the present disclosure. Fig. 8 (a) is an exemplary diagram of a gap structure before bonding, and fig. 8 (b) is an exemplary diagram of a gap structure after bonding.

As shown in fig. 8, the PCB 800 includes a core 82 and a contact paste layer 83, the contact paste layer 83 is located between two cores 82, the core 82 includes a thick copper 85, the thick copper 85 includes a gap 84, and the gap 84 is generated by the thick copper 85 during the patterning process. The gap 84 may be filled with paste by vacuum pressing the plug hole paste layer 83, that is, the plug hole paste in the thick copper gap 84 and the plug hole paste layer 83 are integrated.

Likewise, there is no interface between the plug paste in the thick copper gap 84 and the plug paste layer 83.

The information related to the plug gel layer 83 can be referred to the above description of the plug gel layer 30.

Optionally, the PCB 800 may further include a PP layer 81, which is superimposed with the core 82 and the plug glue layer 83 to form a multi-layer board. Illustratively, the 6-layer board in FIG. 8 (copper layers include L1-L6) may be formed.

Alternatively, a plurality of core plates 82 and a plurality of plug glue layers 83 can be directly stacked to form a multilayer board, so that the flow glue of which the plug glue layers become liquid during pressing fills the existing gaps.

It should be understood that, in the prior art, because the gap of the thick copper is relatively thick, and the adopted PP layer has poor fluidity or relatively small thickness, etc., for filling the thick copper gap, a resin filling flow needs to be added layer by layer in the processing process, which causes complexity of the process, and the mechanical property of the prepared PCB is relatively poor. According to the scheme, the thick copper gap can be directly filled through the flowing glue during pressing, resin filling procedures do not need to be added layer by layer, and therefore the procedure design can be simplified, and the cost can be reduced. Meanwhile, the gap of the thick copper pattern is filled fully by the laminating glue flow, the plug hole glue and the plug hole glue layer in the thick copper gap are in an integrated structure and have no interface, lamination cracks and the like, the PCB can be prevented from being subjected to lamination cracking under the stress action, and the mechanical performance of the PCB can be improved.

The application also provides an electronic device comprising the PCB plug hole structural design and/or the thick copper gap structural design. Alternatively, the electronic device may be a communication device such as a mobile phone, a computer, a base station antenna, and the like.

The above description is only for the specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present application, and shall be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.