A method for preparing a printed circuit board and a printed circuit board

Abstract

The present invention discloses a method for preparing a printed circuit board and a printed circuit board. The method for preparing the printed circuit board comprises: providing a sub-board, wherein the surface of the sub-board is provided with a plurality of first conductive parts, and the sub-board is provided with at least one concave structure, wherein the concave structure is provided with a plurality of second conductive parts; forming a graphic conductive layer in the concave structure and on the surface of the sub-board, wherein the graphic conductive layer is provided with a plurality of third conductive parts, part of the third conductive parts are connected to the first conductive parts, and part of the third conductive parts are connected to the second conductive parts. The technical solution provided by the embodiment of the present invention improves the integration of the printed circuit board.

Description

Technical Field

[0001] The present invention relates to the field of electronic technology, and in particular to a method for preparing a printed circuit board and a printed circuit board. Background Art

[0002] With the development of communication technology, all kinds of electronic devices are developing towards light, thin, short, small and high-density. In the increasingly compressed space, denser lines and more densely packed electronic components are required to realize highly integrated electronic devices.

[0003] Mounting electronic components on the surface of a daughter board using traditional surface mount technology can no longer meet the requirements of high integration of printed circuit boards. Summary of the invention

[0004] The invention provides a method for preparing a printed circuit board and the printed circuit board, so as to improve the integration of the printed circuit board.

[0005] According to one aspect of the present invention, there is provided a method for preparing a printed circuit board, comprising:

[0006] A daughter board is provided, wherein a surface of the daughter board is provided with a plurality of first conductive parts, the daughter board is provided with at least one concave structure, wherein the concave structure is provided with a plurality of second conductive parts;

[0007] A graphic conductive layer is formed in the concave structure and on the surface of the sub-board, wherein the graphic conductive layer is provided with a plurality of third conductive parts, some of which are connected to the first conductive part, and some of which are connected to the second conductive part.

[0008] Optionally, the concave structure includes a sinking cavity located on the first surface of the sub-board, and forming a patterned conductive layer in the concave structure and on the surface of the sub-board includes:

[0009] A solder resist layer is disposed on the second surface of the daughter board, and a patterned conductive layer is formed on the bottom surface and sidewall of the sinking cavity and the first surface of the daughter board, wherein the second surface and the first surface are disposed opposite to each other.

[0010] Optionally, the concave structure includes a sinking cavity located on a first surface and a second surface of the sub-board, and the second surface and the first surface are arranged opposite to each other; and forming a patterned conductive layer in the concave structure and on the surface of the sub-board includes:

[0011] A patterned conductive layer is formed on the bottom surface and side walls of the sinking cavity and the surface of the sub-board.

[0012] Optionally, the concave structure includes a through groove; and forming a patterned conductive layer in the concave structure and on the surface of the sub-board includes:

[0013] A patterned conductive layer is formed on the sidewalls of the through groove and the surface of the sub-board.

[0014] Optionally, forming a patterned conductive layer in the concave structure and on the surface of the sub-board includes:

[0015] Prepare a stack of a cover film and a patterned conductive layer, wherein the cover film is located on a side of the patterned conductive layer away from the sub-board, and the patterned conductive layer includes a plurality of third conductive portions;

[0016] forming a conductive paste on a side of the third conductive portion away from the cover film;

[0017] An insulating adhesive layer is formed on the surface where the stack of the cover film and the patterned conductive layer is pressed against the sub-board, wherein the insulating adhesive layer has no overlap with the orthographic projection of the sub-board and the orthographic projection of the third conductive portion on the sub-board;

[0018] The graphic conductive layer is laminated in the concave structure and on the surface of the sub-board, wherein part of the third conductive part is connected to the first conductive part, and part of the third conductive part is connected to the second conductive part.

[0019] Optionally, before forming a conductive paste on a side of the third conductive portion away from the cover film, the method includes:

[0020] A plurality of first positioning holes are arranged at the edge of the sub-board, and a plurality of second positioning holes are formed at the edge of the stack of the cover film and the patterned conductive layer, wherein the second positioning holes are arranged corresponding to the first positioning holes.

[0021] Optionally, laminating the patterned conductive layer in the concave structure and on the surface of the sub-board includes:

[0022] Providing a pressing mold matching the sub-plate and the concave structure;

[0023] Under high temperature and high pressure conditions, the graphic conductive layer is pressed into the concave structure and onto the surface of the sub-board.

[0024] Optionally, preparing a stack of a cover film and a patterned conductive layer includes:

[0025] Provide covering film;

[0026] Opening windows on the covering film;

[0027] Providing a graphic conductive layer, wherein the size of the graphic conductive layer is the same as the size of the cover film, and the graphic conductive layer comprises copper foil or a flexible core board;

[0028] Performing a patterning process on the patterned conductive layer to form a patterned conductive layer including a plurality of third conductive portions;

[0029] The cover film is pressed onto the patterned conductive layer to form a stack of the cover film and the patterned conductive layer.

[0030] Optionally, after forming the patterned conductive layer in the concave structure and on the surface of the sub-board, the method further includes:

[0031] A surface conductive portion is formed, wherein the surface conductive portion covers the third conductive portion, so as to form a printed circuit board with conductive sidewalls.

[0032] According to another aspect of the present invention, there is provided a printed circuit board, which is prepared by the method for preparing a printed circuit board according to any embodiment of the present invention, comprising:

[0033] A daughter board, wherein a surface of the daughter board is provided with a plurality of first conductive parts, and the daughter board is provided with at least one concave structure, wherein the concave structure is provided with a plurality of second conductive parts;

[0034] A graphic conductive layer is formed in the concave structure and on the surface of the sub-board, wherein the graphic conductive layer is provided with a plurality of third conductive parts, some of which are connected to the first conductive part, and some of which are connected to the second conductive part.

[0035] In the technical solution provided by the present embodiment, the sub-board is provided with a concave structure. The provision of the concave structure increases the surface area of ​​the sub-board, thereby increasing the number of conductive parts that can be provided on the sub-board. The first conductive part can be provided on the surface of the sub-board, and the second conductive part can be provided on the side wall or bottom surface of the concave structure. The first conductive part on the surface of the sub-board and the second conductive part in the concave structure can be electrically connected to the third conductive part of the graphic conductive layer, thereby increasing the patch area of ​​the printed circuit board, and further meeting the design requirements of miniaturization, high density and high integration of terminal electronic products.

[0036] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0038] Figure 1 is a flow chart of a method for preparing a printed circuit board provided according to an embodiment of the present invention;

[0039] Figure 2 and Figure 3 It is a structural schematic diagram corresponding to each step of a method for preparing a printed circuit board provided in an embodiment of the present invention;

[0040] Figure 4 is a schematic structural diagram of a printed circuit board provided according to an embodiment of the present invention;

[0041] Figure 5 is a schematic structural diagram of another printed circuit board provided according to an embodiment of the present invention;

[0042] Figure 6 is a flow chart of another method for preparing a printed circuit board provided according to an embodiment of the present invention;

[0043] Figure 7-Figure 11 It is a structural schematic diagram corresponding to each step of another method for preparing a printed circuit board provided in an embodiment of the present invention;

[0044] Fig.12 is a flow chart of another method for preparing a printed circuit board provided according to an embodiment of the present invention;

[0045] Figure 13-Figure 17 is a structural schematic diagram of a method for preparing a stack of a cover film and a patterned conductive layer provided in an embodiment of the present invention;

[0046] Fig.18 It is a structural schematic diagram corresponding to each step of another method for preparing a printed circuit board provided by the present invention;

[0047] Fig.19 It is a structural schematic diagram corresponding to each step of another method for preparing a printed circuit board provided according to the implementation of the present invention. DETAILED DESCRIPTION

[0048] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings 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 should fall within the scope of protection of the present invention.

[0049] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0050] In order to improve the integration of printed circuit boards, the embodiments of the present invention provide the following technical solutions:

[0051] Figure 1 The present invention is a flowchart of a method for preparing a printed circuit board according to an embodiment of the present invention. Figure 2 and Figure 3 It is a structural schematic diagram corresponding to each step of a method for preparing a printed circuit board provided according to an embodiment of the present invention. Figure 4 The figure is a schematic diagram of the structure of a printed circuit board provided according to an embodiment of the present invention. Figure 5 is a schematic diagram of the structure of another printed circuit board provided according to an embodiment of the present invention. Figure 1 , the preparation method comprises the following steps:

[0052] S110, providing a daughter board, wherein a surface of the daughter board is provided with a plurality of first conductive parts, and the daughter board is provided with at least one concave structure, wherein the concave structure is provided with a plurality of second conductive parts.

[0053] See also Figure 2 , a sub-board 001 is provided, the surface of the sub-board 001 includes a first surface and a second surface arranged opposite to the first surface, and the first surface and the second surface of the sub-board 001 are provided with a plurality of first conductive parts 10. Exemplarily, the sub-board 001 is provided with a concave structure 002, and the concave structure 002 is provided with a plurality of second conductive parts 20. Optionally, the sub-board 001 may include a multi-layer core board, and the core boards are pressed together by bonding sheets. The bonding sheet may be, for example, a prepreg.

[0054] S120, forming a graphic conductive layer in the concave structure and on the surface of the sub-board, wherein the graphic conductive layer is provided with a plurality of third conductive parts, some of the third conductive parts are connected to the first conductive parts, and some of the third conductive parts are connected to the second conductive parts.

[0055] Optional, see Figure 2 and Figure 3The concave structure 002 includes a sinking cavity located on the first surface of the daughter board 001, and a patterned conductive layer 003 is formed in the concave structure 002 and on the surface of the daughter board 001, including: a solder resist layer W0 is provided on the second surface of the daughter board 001, and a patterned conductive layer 003 is formed on the concave structure 002, such as the bottom surface and sidewall of the sinking cavity, and the first surface of the daughter board 001, wherein the second surface and the first surface are arranged opposite to each other. The patterned conductive layer 003 is provided with a plurality of third conductive parts 30, some of which are connected to the first conductive part 10, and some of which are connected to the second conductive part 20.

[0056] Optional, see Figure 4 The concave structure 002 includes a sinking cavity located on the first surface and the second surface of the sub-board 001, and the second surface and the first surface are arranged opposite to each other; a graphic conductive layer 003 is formed in the concave structure 002 and on the surface of the sub-board 001, including: the graphic conductive layer 003 is formed on the concave structure 002, such as the bottom surface and side wall of the sinking cavity, and the first surface and the second surface of the sub-board 001, and the graphic conductive layer 003 is provided with a plurality of third conductive parts 30, some of the third conductive parts 30 are connected to the first conductive part 10, and some of the third conductive parts 30 are connected to the second conductive part 20.

[0057] Optional, see Figure 5 The concave structure 002 includes a through groove; forming a graphic conductive layer 003 in the concave structure 002 and on the surface of the sub-board 001 includes: forming a graphic conductive layer 003 on the sidewall of the concave structure 002, such as the through groove, and on the surface of the sub-board 001.

[0058] In the technical solution provided in this embodiment, the sub-board 001 is provided with a concave structure 002. The provision of the concave structure 002 increases the surface area of ​​the sub-board 001, thereby increasing the number of conductive parts that can be provided on the sub-board 001. The first conductive part 10 can be provided on the surface of the sub-board 001, and the second conductive part 20 can be provided on the side wall or bottom surface of the concave structure 002. The first conductive part 10 on the surface of the sub-board 001 and the second conductive part 20 in the concave structure 002 can both be electrically connected to the third conductive part 30 of the graphic conductive layer 003, thereby increasing the patch area of ​​the printed circuit board, thereby meeting the design requirements of miniaturization, high density and high integration of terminal electronic products.

[0059] It should be noted that the first conductive portion 10 , the second conductive portion 20 and the third conductive portion 30 in the embodiment of the present invention may be pads or conductive lines.

[0060] Figure 6 The present invention is a flowchart of another method for preparing a printed circuit board according to an embodiment of the present invention. Figure 7-Figure 111 is a schematic diagram of the structure corresponding to each step of another method for preparing a printed circuit board provided according to an embodiment of the present invention. Figure 3 Take the structural diagram of the printed circuit board shown as an example, see Figure 6 , the preparation method comprises the following steps:

[0061] S210, providing a daughter board, wherein a surface of the daughter board is provided with a plurality of first conductive parts, and the daughter board is provided with at least one concave structure, wherein the concave structure is provided with a plurality of second conductive parts.

[0062] See also Figure 2 , providing a sub-board 001, wherein the first surface of the sub-board 001 is provided with a plurality of first conductive parts 10, and the sub-board 001 is provided with a concave structure 002, wherein the concave structure 002 is provided with a plurality of second conductive parts 20. It should be noted that the implementation process and beneficial effects of S210 can refer to the implementation process and beneficial effects of S110.

[0063] S220, preparing a stack of a covering film and a patterned conductive layer, wherein the covering film is located on a side of the patterned conductive layer behind the ion plate, and the patterned conductive layer includes a plurality of third conductive portions.

[0064] See also Figure 7 , prepare a stack of a cover film 40 and a patterned conductive layer 003, wherein the patterned conductive layer 003 includes a plurality of third conductive portions 30. The cover film 40 can be used as a surface solder resist layer of the patterned conductive layer 003. Copper foil is selected as the patterned conductive layer 003, and the patterned conductive layer 003 corresponds to Figure 3 and Figure 4 The patterned conductive layer 003 in the printed circuit board is shown.

[0065] S230 , forming a conductive paste on a side of the third conductive portion away from the cover film.

[0066] See also Figure 8 , a conductive paste 50 may be formed on a side of the third conductive portion 30 away from the cover film 40 by a screen printing process.

[0067] S240, forming an insulating adhesive layer on the surface where the stack of the cover film and the patterned conductive layer is pressed against the daughter board, wherein the orthographic projection of the insulating adhesive layer on the daughter board and the orthographic projection of the third conductive part on the daughter board do not overlap.

[0068] See also Fig. 9, an insulating adhesive layer 60 is formed on the surface where the stack of the covering film 40 and the graphic conductive layer 003 is pressed against the sub-board 001, wherein the orthographic projection of the insulating adhesive layer 60 on the sub-board 001 and the orthographic projection of the third conductive part 30 on the sub-board 001 do not overlap. Exemplarily, the insulating adhesive layer 60 can be pure glue. After the insulating adhesive layer 60 passes through the window opening, it is necessary to align the position with the graphic conductive layer 003, so that the orthographic projection of the insulating adhesive layer 60 on the sub-board 001 and the orthographic projection of the third conductive part 30 on the sub-board 001 do not overlap, and then under a certain temperature and pressure, the insulating adhesive layer 60 is formed on the surface where the stack of the covering film 40 and the graphic conductive layer 003 is pressed against the sub-board 001.

[0069] S250, laminating the patterned conductive layer in the concave structure and on the surface of the daughter board, wherein part of the third conductive portion is connected to the first conductive portion, and part of the third conductive portion is connected to the second conductive portion.

[0070] For example, Fig.10 In the printed circuit board in the embodiment, the first surface of the sub-board 001 is provided with a sinking cavity, and the bottom surface and side wall of the sinking cavity and the first surface of the sub-board 001 form a patterned conductive layer 003. A step-type gasket is selected as the pressing mold 004, and under high temperature and high pressure, see Fig.10 and Fig.11 , the graphic conductive layer 003 is pressed into the concave structure 002 and on the surface of the daughter board 001 , wherein part of the third conductive part 30 is connected to the first conductive part 10 , and part of the third conductive part 30 is connected to the second conductive part 20 .

[0071] On the basis of the above technical solution, the graphic conductive layer 003 realizes partial connection between the third conductive part 30 and the first conductive part 10 through the conductive paste 50, and partial connection between the third conductive part 30 and the second conductive part 20, and realizes fixed connection with the sub-board 001 during the lamination process through the insulating adhesive layer 60.

[0072] Fig.12 is a flow chart of another method for preparing a printed circuit board according to an embodiment of the present invention. Based on the above technical solution, this embodiment further defines the step before S230 forms a conductive paste on the side of the third conductive portion away from the cover film. Fig.12 , before forming a conductive paste on a side of the third conductive portion away from the cover film, S230 includes:

[0073] S2301. A plurality of first positioning holes are arranged at the edge of the sub-board, and a plurality of second positioning holes are formed at the edge of the stack of the cover film and the pattern conductive layer, wherein the second positioning holes are arranged corresponding to the first positioning holes.

[0074] See also Fig.10, a plurality of first positioning holes T1 are arranged at the edge of the sub-board 001. Figure 7 A plurality of second positioning holes T2 are formed at the edge of the stack of the cover film 40 and the patterned conductive layer 003. Fig.10 The second positioning hole T2 is arranged corresponding to the first positioning hole T1. By aligning the first positioning hole T1 and the second positioning hole T2, it is convenient to align the patterned conductive layer 003 and the sub-board 001.

[0075] Based on the above technical solution, continue to refer to Fig.12 , S250 laminates the graphic conductive layer in the concave structure and on the surface of the daughter board including:

[0076] S2501. Provide a pressing mold that matches the sub-board and the concave structure.

[0077] See also Fig.10 , providing a pressing mold 004 matching the sub-board 001 and the concave structure 002. Exemplarily, Fig.10 In the printed circuit board in, the first surface of the sub-board 001 is provided with a sinking cavity, and the bottom surface and side walls of the sinking cavity and the first surface of the sub-board 001 form a graphic conductive layer 003. A step-type gasket is selected as the pressing mold 004. Specifically, the meaning of the pressing mold 004 matching the sub-board 001 and the concave structure 002 can be understood as follows: the shape of the step in the pressing mold 004 matching the sub-board 001 and the concave structure 002 is the same as the shape of the sinking cavity, and the size is slightly smaller than the size of the sinking cavity to ensure that it can be placed in the sinking cavity. The pressing mold 004, such as silicone, has a certain elasticity after being heated. During the pressing process of the sub-board 001 and the graphic conductive layer 003, the graphic conductive layer 003 can be prevented from being damaged by external forces.

[0078] S2502. Under high temperature and high pressure conditions, the graphic conductive layer is laminated inside the concave structure and on the surface of the sub-board.

[0079] See also Fig.11 , under high temperature and high pressure, the patterned conductive layer 003 is pressed into the concave structure 002 and on the surface of the daughter board 001, wherein part of the third conductive part 30 is connected to the first conductive part 10, and part of the third conductive part 30 is connected to the second conductive part 20. The copper foil is electrically connected to the first conductive part 10 on the surface of the daughter board 001 and the second conductive part 20 of the concave structure 002 through the conductive paste.

[0080] It should be noted that Fig.10 and Fig.11 Shows Figure 3 In the embodiment, the concave structure 002 includes the steps of pressing the patterned conductive layer into the concave structure and onto the surface of the sub-board corresponding to the sinking cavity. Fig.19The figure shows the steps of laminating the patterned conductive layer in the concave structure and on the surface of the daughter board when the concave structure 002 includes a through groove. Fig.19 The pressing mold 004 that matches the sub-plate 001 and the concave structure 002 includes a first sub-pressing mold 004a and a second sub-pressing mold 004b, and the second sub-pressing mold 004b is provided with a groove that matches the step shape and size of the first sub-pressing mold 004a. The groove is used to limit the step. The step width is slightly smaller than the through groove size to ensure that it can be placed in the through groove. In this embodiment, the pressing mold 004 that matches the concave structure 002 and the sub-plate 001 can be selected according to the specific shape and size of the concave structure 002 and the sub-plate 001.

[0081] On the basis of the above technical solution, a pressing mold 004 matching the sub-board 001 and the concave structure 002 is provided, and the graphic conductive layer 003 is pressed inside the concave structure 002 and on the surface of the sub-board 001 under high temperature and high pressure, thereby achieving a fixed connection between the sub-board 001 and the graphic conductive layer 003.

[0082] Figure 13-Figure 17 FIG. 1 is a schematic diagram of a method for preparing a stack of a cover film and a patterned conductive layer according to an embodiment of the present invention. Fig.12 , S220 prepares the stack of cover film and graphic conductive layer including:

[0083] S2201. Provide a covering film.

[0084] See also Fig.13 , a covering film 40 is provided.

[0085] S2202, opening windows in the covering film.

[0086] See also Fig.14 and Fig.11 , a window is opened in the cover film 40 , wherein the window opening position matches the third conductive portion 30 of the pattern conductive layer 003 .

[0087] S2203, providing a graphic conductive layer, wherein the size of the graphic conductive layer is the same as the size of the cover film, and the graphic conductive layer includes copper foil or a flexible core board.

[0088] See also Fig.15 , providing a patterned conductive layer 003, wherein the size of the patterned conductive layer 003 is the same as the size of the cover film 40. Exemplarily, Figure 3 and Fig.15 In the embodiment, the patterned conductive layer 003 includes copper foil. Figure 5 In the embodiment, the patterned conductive layer 003 includes a flexible core board. The flexible core board is a flexible copper clad board. It should be noted that: Figure 3 and Figure 4The graphic conductive layer 003 in the circuit can also be a flexible core board. Figure 5 Copper foil can also be selected for the graphic conductive layer 003.

[0089] S2204, performing patterning processing on the patterned conductive layer to form a patterned conductive layer including a plurality of third conductive portions.

[0090] See also Fig.16 , forming a protective film layer L1 and a mask plate L2. Fig.16 and Fig.17 The patterned conductive layer 003 is patterned by photolithography and etching processes to form a patterned conductive layer 003 including a plurality of third conductive portions 30 .

[0091] S2205, laminating the cover film on the patterned conductive layer to form a stack of the cover film and the patterned conductive layer.

[0092] See also Fig.17 , the cover film 40 is pressed onto the patterned conductive layer 003 to form a stack of the cover film 40 and the patterned conductive layer 003 .

[0093] It should be noted that Figure 13-Figure 17 as well as Figure 7-Figure 9 The method for preparing copper foil as the patterned conductive layer 003 is shown. Fig.18 Shows Figure 5 When the medium flexible core board is used as the pattern conductive layer 003, the preparation method of the pattern conductive layer 003. Fig.18 The flexible core board is used as the graphic conductive layer 003, and the graphic conductive layer 003 can be set with more complex conductive circuits than copper foil.

[0094] On the basis of the above technical solution, the patterned conductive layer 003 needs to form a third conductive portion 30 that matches the specific position of the first conductive portion 10 of the daughter board 001 and the second conductive portion 20 of the concave structure 002 through photolithography and etching processes. The cover film 40, as the solder resist layer of the patterned conductive layer 003, needs to be opened before being pressed with the patterned conductive layer 003, and the specific position of the opening needs to match the position of the third conductive portion 30.

[0095] Based on the above technical solution, continue to refer to Fig.12 After forming a patterned conductive layer in the concave structure and on the surface of the sub-board, S250 also includes:

[0096] S260, forming a surface conductive portion, wherein the surface conductive portion covers the third conductive portion to form a printed circuit board with conductive sidewalls.

[0097] See also Fig.19After forming the graphic conductive layer 003 inside the concave structure 002 and on the surface of the sub-board 001, the printed circuit board can be surface treated to be flattened and cleaned, and then a surface conductive portion 70 is formed, wherein the surface conductive portion 70 covers the third conductive portion 30 to form a printed circuit board with sidewall conduction.

[0098] The embodiment of the present invention also provides a printed circuit board. Figure 3-Figure 5 The printed circuit board is prepared by any of the printed circuit board preparation methods described in the above technical solutions, including: a sub-board 001, wherein a plurality of first conductive parts 10 are arranged on the surface of the sub-board 001, and the sub-board 001 is provided with at least one concave structure 002, wherein the concave structure 002 is provided with a plurality of second conductive parts 20; a graphic conductive layer 003, wherein the graphic conductive layer 003 is formed in the concave structure 002 and on the surface of the sub-board 001, wherein the graphic conductive layer 003 is provided with a plurality of third conductive parts 30, part of the third conductive parts 30 is connected to the first conductive parts 10, and part of the third conductive parts 30 is connected to the second conductive parts 20.

[0099] In the technical solution provided in this embodiment, the sub-board 001 is provided with a concave structure 002. The provision of the concave structure 002 increases the surface area of ​​the sub-board 001, thereby increasing the number of conductive parts that can be provided on the sub-board 001. The first conductive part 10 can be provided on the surface of the sub-board 001, and the second conductive part 20 can be provided on the side wall or bottom surface of the concave structure 002. The first conductive part 10 on the surface of the sub-board 001 and the second conductive part 20 in the concave structure 002 can both be electrically connected to the third conductive part 30 of the graphic conductive layer 003, thereby increasing the patch area of ​​the printed circuit board, thereby meeting the design requirements of miniaturization, high density and high integration of terminal electronic products.

[0100] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a printed circuit board, characterized in that: include: A daughter board is provided, wherein a surface of the daughter board is provided with a plurality of first conductive parts, the daughter board is provided with at least one concave structure, wherein the concave structure is provided with a plurality of second conductive parts; A graphic conductive layer is formed in the concave structure and on the surface of the sub-board, wherein the graphic conductive layer is provided with a plurality of third conductive parts, some of the third conductive parts are connected to the first conductive part, and some of the third conductive parts are connected to the second conductive part; A plurality of the second conductive parts are disposed on the side wall of the concave structure.

2. The method for preparing a printed circuit board according to claim 1, characterized in that: The concave structure includes a sinking cavity located on the first surface of the sub-board, and forming a patterned conductive layer in the concave structure and on the surface of the sub-board includes: A solder resist layer is disposed on the second surface of the daughter board, and a patterned conductive layer is formed on the bottom surface and side walls of the sinking cavity and the first surface of the daughter board, wherein the second surface and the first surface are disposed opposite to each other.

3. The method for preparing a printed circuit board according to claim 1, characterized in that: The concave structure comprises a sinking cavity located on a first surface and a second surface of the sub-board, and the second surface and the first surface are arranged opposite to each other; Forming a patterned conductive layer in the concave structure and on the surface of the sub-board includes: A patterned conductive layer is formed on the bottom surface and side walls of the sinking cavity and the surface of the sub-board.

4. The method for preparing a printed circuit board according to claim 1, characterized in that: The concave structure includes a through groove; and forming a patterned conductive layer in the concave structure and on the surface of the sub-board includes: A patterned conductive layer is formed on the sidewalls of the through groove and the surface of the sub-board.

5. The method for preparing a printed circuit board according to claim 1, characterized in that: Forming a patterned conductive layer in the concave structure and on the surface of the sub-board includes: Prepare a stack of a cover film and a patterned conductive layer, wherein the cover film is located on a side of the patterned conductive layer away from the sub-board, and the patterned conductive layer includes a plurality of third conductive portions; forming a conductive paste on a side of the third conductive portion away from the cover film; An insulating adhesive layer is formed on the surface where the stack of the cover film and the patterned conductive layer is pressed against the sub-board, wherein the insulating adhesive layer has no overlap with the orthographic projection of the sub-board and the orthographic projection of the third conductive portion on the sub-board; The graphic conductive layer is laminated in the concave structure and on the surface of the sub-board, wherein part of the third conductive part is connected to the first conductive part, and part of the third conductive part is connected to the second conductive part.

6. The method for preparing a printed circuit board according to claim 5, characterized in that: Before forming a conductive paste on a side of the third conductive portion away from the cover film, the method includes: A plurality of first positioning holes are arranged at the edge of the sub-board, and a plurality of second positioning holes are formed at the edge of the stack of the cover film and the patterned conductive layer, wherein the second positioning holes are arranged corresponding to the first positioning holes.

7. The method for preparing a printed circuit board according to claim 5, characterized in that: Laminating the patterned conductive layer in the concave structure and on the surface of the sub-board includes: Providing a pressing mold matching the sub-plate and the concave structure; Under high temperature and high pressure conditions, the graphic conductive layer is pressed into the concave structure and onto the surface of the sub-board.

8. The method for preparing a printed circuit board according to claim 5, characterized in that: The stacking of the cover film and the patterned conductive layer includes: Provide covering film; Opening windows on the covering film; Providing a graphic conductive layer, wherein the size of the graphic conductive layer is the same as the size of the cover film, and the graphic conductive layer comprises copper foil or a flexible core board; Performing a patterning process on the patterned conductive layer to form a patterned conductive layer including a plurality of third conductive portions; The cover film is pressed onto the patterned conductive layer to form a stack of the cover film and the patterned conductive layer.

9. The method for preparing a printed circuit board according to claim 1, characterized in that: After forming a patterned conductive layer in the concave structure and on the surface of the sub-board, the method further includes: A surface conductive portion is formed, wherein the surface conductive portion covers the third conductive portion to form a printed circuit board with conductive sidewalls.

10. A printed circuit board, characterized in that: The printed circuit board is prepared by the method for preparing the printed circuit board according to any one of claims 1 to 9, comprising: A daughter board, wherein a surface of the daughter board is provided with a plurality of first conductive parts, and the daughter board is provided with at least one concave structure, wherein the concave structure is provided with a plurality of second conductive parts; A graphic conductive layer is formed in the concave structure and on the surface of the sub-board, wherein the graphic conductive layer is provided with a plurality of third conductive parts, some of which are connected to the first conductive part, and some of which are connected to the second conductive part.

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