CN113853056B

CN113853056B - Packaging module, board-to-board connection structure, manufacturing method thereof and terminal

Info

Publication number: CN113853056B
Application number: CN202110984355.9A
Authority: CN
Inventors: 刘鹏; 盛明; 李梦园
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2021-08-25
Filing date: 2021-08-25
Publication date: 2023-07-07
Anticipated expiration: 2041-08-25
Also published as: CN113853056A

Abstract

The application provides a packaging module, include: the packaging substrate comprises a substrate, a first circuit layer, an electronic component electrically connected with the first circuit layer and a first packaging layer which is positioned on the substrate and packages the electronic component and the first circuit layer; the electric connection layer is arranged on the surface of the first packaging layer and is electrically connected with the first circuit layer; the connecting pads are arranged on the surface of the electric connecting layer, which is away from the first packaging layer, and are electrically connected with the electric connecting layer. The application also provides a board-to-board connection structure and a terminal applying the packaging module, and a preparation method of the packaging module and the board-to-board connection structure. The thickness of the packaging module can be greatly reduced by arranging the electric connection layer and the connection pad on the surface of the packaging substrate, so that the board-to-board connection structure and the light, thin, short and small terminal are facilitated.

Description

Packaging module, board-to-board connection structure, manufacturing method thereof and terminal

Technical Field

The application relates to a packaging module capable of reducing total thickness, a preparation method of the packaging module, a board-to-board connection structure applying the packaging module, a preparation method of the board-to-board connection structure and a terminal.

Background

With the wide application of circuit boards in the electronic field, in order to perform the functions of electronic products, two or more circuit boards with different functions are generally integrated together by means of connection.

However, as electronic products are increasingly developed toward slimness and shortness, the existing circuit board-to-circuit board connection needs to take into consideration the problem of excessive total thickness.

Disclosure of Invention

The first aspect of the embodiment of the application provides a packaging module, which comprises a packaging substrate, an electric connection layer and a connection pad, wherein the packaging substrate comprises a substrate, a first circuit layer arranged on the substrate, an electronic component arranged on the substrate and electrically connected with the first circuit layer, and a first packaging layer which is arranged on the substrate and packages the electronic component and the first circuit layer, and the first packaging layer comprises a first surface close to the substrate, a second surface deviating from the first surface and a side surface connecting the first surface and the second surface; the electric connection layer is arranged on the second surface and/or the side surface and is electrically connected with the first circuit layer; the connecting pad is arranged on the surface of the electric connecting layer, which is away from the first packaging layer, and is electrically connected with the electric connecting layer.

According to the electronic packaging module, the electric connection layer is arranged on the surface of the first packaging layer, and then the connection pad is led out of the electric connection layer, so that the size of the packaging module can be reduced, the thickness of the packaging module is reduced, the area of the board-to-board connector on the packaging substrate is saved, the weight of the packaging module is obviously reduced, the preparation process of the electric connection layer and the connection pad is simple, the realization and mass production are easy, the cost is low, and the electronic packaging module is light, thin and short; in addition, the existing structure form of the packaging matrix does not need to be changed, and the adaptability is high.

In some embodiments, the electrical connection layer is disposed on the second surface, the package substrate further includes a through hole penetrating through the first surface and the second surface, a conductor is disposed in the through hole, one end of the conductor is electrically connected to the first circuit layer, and the other end of the conductor is exposed on the second surface and is electrically connected to the electrical connection layer.

The vertical punching mode is adopted, so that the conductor is buried in the first packaging layer, and the space outside the packaging matrix is not required to be occupied, thereby improving the space utilization rate of the packaging matrix, being beneficial to reducing the volume of the packaging module, and especially reducing the thickness of the packaging module.

In some embodiments, the first encapsulation layer includes an encapsulation region encapsulating the electronic component and an edge region located at a periphery of the encapsulation region, and the via and the conductor are located at the edge region.

The peripheral free area of the first packaging layer can be fully utilized, a plurality of connecting pads can be led out, a plurality of circuit boards can be connected in the subsequent board-to-board connection process, and the space outside the packaging matrix is not required to be occupied, so that the space utilization rate of the packaging matrix is improved, and the size of the packaging module is reduced; moreover, the through holes are arranged in the edge area where the electronic components are not arranged, so that the connection reliability of the electronic components and the substrate is not affected; in addition, the embedded conductor can be realized by arranging the through holes in the edge area of the first packaging layer in the existing packaging module without changing the structural form of the existing packaging module, so that the process can be simplified, the laminate is reduced, and the applicability is provided.

In some embodiments, the electrical connection layer includes a second circuit layer and a dielectric layer, the second circuit layer is embedded in the dielectric layer, the second circuit layer includes a first wire and a second wire, two ends of the first wire are respectively electrically connected with the conductor and the second wire, and one end of the second wire, which is away from the first wire, is exposed from the surface of the dielectric layer, which is away from the package substrate, and is electrically connected with the connection pad.

The adoption of the rewiring technology can amplify the distance between conductors with higher distribution density, so that the distribution of the connection pads is more reasonable, and the subsequent connection of the circuit board is facilitated.

In some embodiments, the substrate includes a substrate surface disposed near the first packaging layer, the first circuit layer is disposed on the substrate surface, the substrate is disposed beyond the side surface of the first packaging layer, the side surface and the substrate surface enclose a containing space together, the first circuit layer extends to the containing space, and the electrical connection layer is disposed on the side surface and is contained in the containing space.

Through set up the electric tie layer at the side surface of first encapsulation layer, need not to increase the thickness of encapsulation base member, can make full use of encapsulation base member's side space, be favorable to improving encapsulation module's space utilization, reduce encapsulation module's thickness simultaneously, be favorable to the frivolous shortness of electronic product to be miniaturized, set up the electric tie layer at the side surface of first encapsulation layer moreover, improved encapsulation module structural design's flexibility.

In some embodiments, the electrical connection layer includes a second circuit layer, a third circuit layer disposed on a side of the second circuit layer near the substrate, and a dielectric layer, where the second circuit layer is embedded in the dielectric layer, the third circuit layer is electrically connected to the first circuit layer, and the second circuit layer is electrically connected to the third circuit layer.

The electric connection layer can be realized by adopting the forming process of the circuit board, the process is mature, the cost is reduced, the structure of the packaging matrix is not required to be changed, and the adaptability is strong.

In some embodiments, the second circuit layer includes a first conductive line and a second conductive line, the second conductive line is electrically connected to the third circuit layer and the first conductive line, and one end of the first conductive line facing away from the second conductive line is exposed from a surface of the dielectric layer facing away from the first encapsulation layer and is electrically connected to the connection pad.

The first lead is led out from the side surface of the electric connection layer and is electrically connected with the connection pad, so that the structure is simple and easy to realize.

In some embodiments, the number of the electrical connection layers is at least two, the second surface is provided with one electrical connection layer, the package substrate further includes a through hole penetrating through the first surface and the second surface, a conductor is disposed in the through hole, one end of the conductor is electrically connected with the first circuit layer, and the other end of the conductor is exposed on the second surface and is electrically connected with the electrical connection layer; the side surface is provided with another electric connection layer, the base plate is including being close to the base plate surface that first encapsulation layer set up, first circuit layer set up in the base plate surface, the base plate surpasses first encapsulation layer the side surface sets up, the side surface with the base plate surface encloses into an accommodation space jointly, first circuit layer extends to accommodation space, another electric connection layer set up in the side surface and hold in accommodation space.

Through setting up different electric connection layer at second surface and at least one side surface, can realize the purpose that leads out the circuit setting connection pad at the arbitrary surface of encapsulation base member according to actual need, be favorable to promoting encapsulation module structural design's flexibility.

In some embodiments, the packaging module further comprises a second packaging layer that encapsulates the first packaging layer and the electrical connection layer.

The second packaging layer wraps the first packaging layer and the electric connection layer to form a whole, so that the binding force between the electric connection layer and the first packaging layer is conveniently improved, the stability of electric connection between the electric connection layer and the packaging substrate is improved, and reliability is provided.

The second aspect of the embodiments of the present application provides a board-to-board connection structure, where the board-to-board connection structure includes the above-mentioned package module and a first functional module, where the first functional module is disposed on the connection pad, and is electrically connected with the package substrate through the connection pad and the electrical connection layer.

Through design electric connection layer and connection pad realization and first functional module's electric connection in encapsulation module, compare on the encapsulation base member direct welding board to board connector, saved the overall arrangement area of board to board connector completely, weight is showing and is reducing, is favorable to frivolous short miniaturization of electronic product. In addition, the electric connection layer and the connection pad have simple structure, are easy to form, do not need to change the structural form of the packaging matrix, have low cost and are convenient for mass production.

In some embodiments, a connection layer is disposed between the connection pad and the first functional module, and the connection layer includes anisotropic conductive adhesive or solder paste.

The first functional module is electrically connected with the connecting pad through the mode of sticking the anisotropic conductive adhesive or soldering tin, so that the operation is convenient, the thickness of the anisotropic conductive adhesive or soldering tin paste is thinner, the overlarge space cannot be occupied, and the total thickness of the board-to-board connecting structure is reduced. Moreover, the connection stability is high, and the problem of reliability reduction can not occur under the condition that the board-to-board connection structure is bent or rocked. In addition, the process for sticking the anisotropic conductive adhesive or soldering tin is simple, the efficiency is high, and the cost is low.

In some embodiments, the board-to-board connection structure further includes a functional module disposed on a side of the substrate facing away from the electronic component, and the functional module is electrically connected with the package substrate.

The second functional module can be designed according to actual needs, which is beneficial to realizing the multifunction of the electronic product.

A third aspect of the embodiments of the present application provides a terminal, the terminal including a housing and a board-to-board connection structure accommodated in the housing, the board-to-board connection structure being the board-to-board connection structure as described above.

The volume of the board-to-board connection structure can be reduced through the structural design of the packaging module, and especially the total thickness of the board-to-board connection structure is favorable for the light, thin, short and small of the terminal.

A fourth aspect of the present application provides a method for manufacturing a package module, where the method includes: providing a packaging substrate, wherein the packaging substrate comprises a substrate, a first circuit layer arranged on the substrate, an electronic component arranged on the substrate and electrically connected with the first circuit layer, and a first packaging layer which is arranged on the substrate and packages the electronic component and the first circuit layer, and the first packaging layer comprises a first surface close to the substrate, a second surface far away from the first surface and a side surface connecting the first surface and the second surface; forming an electrical connection layer on the second surface and/or the side surface, wherein the electrical connection layer is electrically connected with the first circuit layer; and arranging a connecting pad on the surface of the electric connecting layer, which is away from the first packaging layer, wherein the connecting pad is electrically connected with the electric connecting layer, so that the packaging module is obtained.

The preparation method of the packaging module is simple in process, easy to implement, low in cost and convenient for mass production.

In some embodiments, the first encapsulation layer includes an encapsulation region encapsulating the electronic component and an edge region located at a periphery of the encapsulation region. The preparation method further comprises the steps of, before forming the electric connection layer: punching the edge area to form a through hole, wherein the through hole penetrates through the first surface and the second surface; and forming a conductor in the through hole, wherein the conductor is electrically connected with the first circuit layer, and one end of the conductor, which is away from the first circuit layer, is exposed from the second surface. After the conductors are formed, the preparation method of the electric connection layer comprises the following steps: forming a second circuit layer on the second surface, wherein the second circuit layer comprises a first wire and a second wire, and two ends of the first wire are respectively and electrically connected with the conductor and the second wire; and forming a dielectric layer on the second surface, wherein the second circuit layer is embedded in the dielectric layer, and one end of the second wire, which is away from the first wire, is exposed from the surface of the dielectric layer, so that the electric connection layer is obtained.

The forming method of the through hole and the conductor is simple, easy to realize, low in cost and easy for mass production.

The electric connection layer is added on the side surface of the first packaging layer, the connection mode of the electric connection layer and the packaging matrix is simple and easy to realize, the structure of the existing packaging matrix is not required to be changed, the cost is low, and the mass production is convenient.

In some embodiments, after forming the electrical connection layer, the method of preparing further comprises: and forming a second packaging layer on the surface of the substrate so that the first packaging layer and the electric connection layer are embedded in the second packaging layer.

The second packaging layer is simple in forming, the second packaging layer wraps the first packaging layer and the electric connection layer to form a whole, the binding force between the electric connection layer and the first packaging layer is convenient to improve, the stability of electric connection between the electric connection layer and the packaging substrate is improved, and reliability is provided.

A fifth aspect of the embodiments of the present application provides a method for manufacturing a board-to-board connection structure, including: providing a packaging module as described above; forming a connection layer on the connection pad; and providing a circuit board, and arranging the circuit board on the connecting layer so as to obtain the board-to-board connecting structure.

The preparation method of the plate-to-plate connection structure is simple in process, easy to realize, low in cost and convenient for mass production.

In some embodiments, the connection layer comprises an anisotropic conductive paste or solder paste.

The circuit board and the connecting pad are electrically connected in a mode of sticking the anisotropic conductive adhesive or soldering tin, the process is simple, the operation is convenient, the efficiency is high, and the cost is low.

In some embodiments, the method of making further comprises: and a second functional module is arranged on one side of the substrate, which is away from the first circuit layer, and the second functional module is electrically connected with the first circuit layer.

The connection mode of the second functional module is simple, the operation is convenient, the second functional module can be designed according to actual needs, and the electronic product multifunctionalization is realized.

Drawings

Fig. 1 is a schematic structural view of a board-to-board connection structure according to an embodiment of the present application.

Fig. 2 is a picture of a conventional board-to-board connector.

Fig. 3 is a schematic structural diagram of a package module according to an embodiment of the present application.

Fig. 4 is a top view of a package module according to one embodiment of the present application.

Fig. 5 is a schematic diagram showing the distribution of connection pads in a package module according to a modified embodiment.

Fig. 6 is a schematic structural diagram of a board-to-board connection structure according to another embodiment of the present application.

Fig. 7 is a schematic structural diagram of a package module according to another embodiment of the present application.

Fig. 8 is a schematic structural diagram of an electrical connection layer according to another embodiment of the present application.

Fig. 9 is a side view of an electrical connection layer with connection pads according to another embodiment of the present application.

Fig. 10 is a schematic structural view of a board-to-board connection structure according to still another embodiment of the present application.

Fig. 11 is a schematic structural view of a package substrate according to an embodiment of the present application.

Fig. 12 is a schematic view of a structure in which a via hole is formed in the first package layer provided in fig. 11.

Fig. 13 is a schematic view of a structure in which conductors are formed in the through holes provided in fig. 12.

Fig. 14 is a schematic structural view of forming a second circuit layer on the second surface provided in fig. 13.

Fig. 15 is a schematic view of a structure in which a dielectric layer is formed on the second surface provided in fig. 14.

Fig. 16 is a schematic structural view of a package substrate according to another embodiment of the present application.

Fig. 17 is a schematic view of a structure in which an electrical connection layer is formed on a side surface of the package substrate provided in fig. 16.

Description of the main reference signs

Board-to-

board connection structure

100, 200, 300

Packaging modules

10, 20, 30

Packaging substrates

1a, 1b, 1c

Substrate 11

Substrate surface 111

Electronic component 12

First encapsulation layer 13

First surface 131

Second surface 132

Side surface 133

First circuit layer 14

Through holes 15

Conductor 16

Electric connection layers 2, 6

Second wiring layer

21, 61

First

conductive line

211, 611

Second

conductive line

212, 612

Dielectric layers

22, 64

Third circuit layer 62

Fourth wiring layer 63

Connection pad 3

Solder ball 4

Second encapsulation layer 5

First functional module 40

Function module 50

Detailed Description

Embodiments of the present application are described below with reference to the accompanying drawings in the embodiments of the present application.

As shown in fig. 1, a board-to-board connection structure 100 is provided. The board-to-board connection structure 100 may be provided in a housing of the terminal. The terminal can be an electronic device such as a mobile phone, a notebook computer, a tablet personal computer and the like.

Referring to fig. 1 together with fig. 3, the board-to-board connection structure 100 includes a package module 10 and a first functional module 40 electrically connected to the package module 10. The package module 10 includes a package substrate 1a, where the package substrate 1a may be a system in package (System In a Package, SIP) module or a package on package (Package on Package, POP) module, and in this embodiment, the package substrate 1a is a SIP module. The first functional module 40 may be a printed circuit board (Printed Circuit Board, PCB), a flexible circuit board (Flexible Printed Circuit, FPC), or other functional devices, such as a SIP module or a POP module, etc., and in this embodiment, the first functional module 40 may be an FPC, as shown in fig. 1. In order to achieve the electrical connection and signal transmission between the package substrate 1a (specifically, SIP module) and the first functional module 40, it is generally necessary to use a Board-to-Board (BTB) connector as shown in fig. 2, that is, a male socket a and a female socket b of the BTB are soldered on the package substrate 1a and the first functional module 40, respectively, and the electrical connection and signal interconnection between the two parts are achieved through mechanical fastening. However, when the board-to-board interconnection is implemented, a larger number of BTBs are required, so that the layout area of the package substrate 1a is reduced, and the volume of a single BTB is larger, especially the size along the thickness direction of the package substrate 1a is larger, so that the total thickness of the package substrate 1a and the first functional module 40 after connection is increased, and the development trend of lightness, thinness, shortness and smallness of electronic products cannot be met; further, after the package substrate 1a and the first functional module 40 are connected by BTB, there is a problem that connection reliability is lowered when bending or shaking occurs; in addition, the BTB cost is high, and the production cost of the electronic product is increased. Along with the development trend of miniaturization of consumer electronic products, a board-to-board connection technology with small layout area, flexible architecture, low cost and high production efficiency is urgently needed. Therefore, the upper surface of the package substrate 1a is provided with the electrical connection layer 2 electrically connected with the package substrate 1a, and the plurality of connection pads 3 are led out through the electrical connection layer 2, and the first functional module 40 is electrically connected with the connection pads 3, so that the electrical connection between the package substrate 1a and the first functional module 40 is realized. The thickness of the electrical connection layer 2 and the connection pad 3 may be designed according to actual needs, so that the total thickness of the overall board-to-board connection structure 100 may be effectively reduced, which is beneficial to the light, thin and small terminal.

As shown in fig. 3, the package base 1a includes a substrate 11, an electronic component 12 disposed on the substrate 11, and a first package layer 13 disposed on the substrate 11 and encapsulating the electronic component 12.

The surface of the substrate 11, which is close to the electronic component 12, is provided with a first circuit layer 14, and the electronic component 12 is electrically connected with the first circuit layer 14.

The electronic components 12 may include one or more passive devices including, but not limited to, resistors, capacitors, inductors, filters, couplers, and the like. The electronic component 12 may also include one or more active devices such as active chips including, but not limited to, power chips, digital chips, radio frequency chips, and the like. The electronic components 12 are packaged in a concentrated manner in the middle of the substrate 11, and the first packaging layer 13 completely encapsulates the electronic components 12.

The first encapsulation layer 13 includes a first surface 131 adjacent to the substrate 11 and a second surface 132 disposed away from the first surface 131. In addition, the first encapsulation layer 13 is divided into an encapsulation area a for encapsulating the electronic component 12 and an edge area B located at the periphery of the encapsulation area a according to the distribution position of the electronic component 12, wherein the edge area B is not provided with the electronic component 12. The package substrate 1a further includes a plurality of through holes 15 disposed in the edge region B, and the plurality of through holes 15 are disposed through the first surface 131 and the second surface 132. A conductor 16 is disposed in the through hole 15, one end of the conductor 16 is electrically connected to the first circuit layer 14 on the substrate 11, and the other end is exposed from the second surface 132 and is electrically connected to the electrical connection layer 2, so as to electrically connect the electrical connection layer 2 and the package substrate 1. In this embodiment, the conductor 16 is buried in the edge region B of the first encapsulation layer 13, so that the peripheral free area of the encapsulation region a can be fully utilized, and the space outside the encapsulation substrate 1a is not required to be occupied, thereby improving the space utilization of the encapsulation substrate 1a and reducing the volume of the board-to-board connection structure 100 formed. Moreover, the provision of the through hole 15 in the edge region B where the electronic component 12 is not provided does not affect the connection reliability between the electronic component 12 and the substrate 11. In addition, without changing the structure form of the existing package substrate 1a (for example, SIP module), the conductor 16 can be embedded by providing the through hole 15 in the edge region B of the existing package substrate 1a, so that the process can be simplified, the cost can be reduced, and the applicability is strong.

The material of the first encapsulation layer 13 may be one selected from epoxy resin (epoxy resin), prepreg (PP), BT resin, polyphenylene oxide (Polyphenylene Oxide, PPO), polyimide (PI), polyethylene terephthalate (Polyethylene Terephthalate, PET), and polyethylene naphthalate (Polyethylene Naphthalate, PEN). Specifically, in this embodiment, the first encapsulation layer 13 is a prepreg.

The through holes 15 are formed by laser drilling or mechanical drilling. The through holes 15 penetrating the first surface 131 and the second surface 132 of the first encapsulation layer 13 are formed by adopting a conventional punching manner, and the punching manner is simple and easy to realize and has low cost.

The conductor 16 is formed by electroplating copper in the through hole 15, and the conductor 16 is formed by electroplating, so that the connection stability of the conductor 16 and the first circuit layer 14 can be improved, the process is simple, the implementation is convenient, and the cost is low; in addition, the conductors 16 can be laid out at the required positions according to actual needs by electroplating, and the structural form of the conductors 16 can be designed according to needs with small limitation. In other embodiments, the conductor 16 may be formed by filling a conductive paste in the through hole 15 and curing, and the conductor 16 is formed by filling a conductive paste and curing, which is simple in process, convenient in operation and low in cost.

As shown in fig. 3 and fig. 4, referring to fig. 1 together, the through holes 15 may be regularly distributed in the edge area B and surround the periphery of the package area a, so that the conductors 16 are disposed around the plurality of electronic components 12, and then the plurality of connection pads 3 are led out to implement interconnection between the plurality of first functional modules 40 and the plurality of electronic components 12. In other embodiments, the through hole 15 may be disposed at a position where the line needs to be led out in the edge area B according to actual needs. The shape of the through hole 15 is not limited, and may be a circular through hole, but may be other shapes, such as a rectangle, a triangle, or other irregular shapes.

The end of the conductor 16 facing away from the substrate 11 grinds away a part of the first encapsulation layer 13 by grinding, so that the end surface of the conductor 16 is completely exposed from the second surface 132, and the subsequent circuit is led out conveniently to form the electrical connection layer 2.

As shown in fig. 3 and 4, the electrical connection layer 2 is a redistribution layer formed by using a redistribution technology (Redistribution Layer, RDL), and the pitch of the conductors 16 with a higher distribution density can be enlarged by using the RDL technology. Specifically, the electrical connection layer 2 includes a second circuit layer 21 and a dielectric layer 22, the second circuit layer 21 is embedded in the dielectric layer 22, the second circuit layer 21 includes a plurality of first conductive lines 211 and second conductive lines 212 disposed substantially perpendicular to the first conductive lines 211, wherein the first conductive lines 211 are disposed substantially parallel to the second surface 132, and the second conductive lines 212 are disposed substantially perpendicular to the second surface 132. One end of each of the first wires 211 is electrically connected to one of the conductors 16, and the other end is electrically connected to one of the second wires 212. One end of the second wire 212 facing away from the first wire 211 is exposed by the dielectric layer 22, and the connection pad 3 is electroplated on the end face of the second wire 212 exposed by the dielectric layer 22. Through the re-wiring design of the electrical connection layer 2, the plurality of conductors 16 with high density and vertical distribution are led out through the plurality of connection pads 3 uniformly distributed on the surface of the dielectric layer 22, so as to be electrically connected with the first functional module 40. In addition, the thickness of the electrical connection layer 2 formed by RDL technology is relatively thin, the second circuit layer 21 is formed by a conventional circuit forming method, and the thickness of the circuit is typically in the micrometer level, and the connection pad 3 is electroplated on the second conductive wire 212 by copper plating, and the thickness can be designed to be very thin according to practical needs, so that the total thickness of the overall board-to-board connection structure 100 is greatly reduced, as shown in fig. 1.

The material of the dielectric layer 22 may be one of epoxy resin (epoxy resin), prepreg (PP), BT resin, polyphenylene oxide (Polyphenylene Oxide, PPO), polyimide (PI), polyethylene terephthalate (Polyethylene Terephthalate, PET), polyethylene naphthalate (Polyethylene Naphthalate, PEN), and the like. Specifically, in this embodiment, the dielectric layer 22 is a prepreg.

As shown in fig. 3, the electrical connection layer 2 is disposed on the upper surface of the package substrate 1a (i.e., the second surface 132 of the first package layer 13), and the electrical connection layer 2 is disposed on the upper surface of the package substrate 1, so that the through holes 15 can be formed directly on the first package layer 13 of the package substrate 1a by vertically punching, and the conductors 16 can be formed in the through holes 15 by electroplating, which does not need to change the existing structural form of the package substrate 1a, thereby facilitating simplification of the process and reduction of the cost.

As shown in fig. 1 and fig. 4, the arrangement of the plurality of connection pads 3 may be set according to the specific location where the first functional module 40 is actually connected, and the plurality of connection pads 3 may be uniformly distributed on the surface of the electrical connection layer 2 in an array arrangement. The shape and size of the connection pad 3 are not limited, and may be circular, as shown in fig. 4, but may be other shapes, such as rectangular, triangular, elongated with a certain length-diameter ratio, or other irregular shapes. The position, the size and the shape of the connection pad 3 can be reasonably set according to the actual layout area of the lead-out line of the electric connection layer 2, so that the layout area of the connection pad 3 is reduced, and the space utilization rate of the packaging module 10 is improved; meanwhile, the position of the connection pad 3 may be set reasonably according to the connection position of the first functional module 40 that is actually connected, so as to improve the flexibility of connection between the first functional module 40 and the packaging module 10.

The plurality of connection pads 3 may be regularly and uniformly arranged, and as shown in fig. 4, the plurality of connection pads 3 may be arranged in an array. In other embodiments, the plurality of connection pads 3 may be irregularly or unevenly arranged. As shown in fig. 5, the plurality of connection pads 3 may have a long shape with different aspect ratios or may have a circular shape. In this way, when it is necessary to connect different first functional modules 40, the arrangement of the plurality of connection pads 3 can be easily distinguished, preventing the connection error of different first functional modules 40.

As shown in fig. 1, the connection pad 3 is electrically connected with the first functional module 40 through a connection layer (not shown), the connection layer may be anisotropic conductive adhesive or solder paste, and the electrical connection between the first functional module 40 and the connection pad 3 is realized by attaching the anisotropic conductive adhesive or solder paste, which is convenient for operation, and the thickness of the anisotropic conductive adhesive or solder paste is thinner, which does not occupy too much space and is beneficial to reducing the total thickness of the board-to-board connection structure 100. Moreover, the first functional module 40 is disposed on the connection pad 3 by sticking the anisotropic conductive adhesive or solder, so that the connection stability is high, and the board-to-board connection structure 100 does not have a problem of reduced reliability when bending or shaking occurs. In addition, the process for sticking the anisotropic conductive adhesive or soldering tin is simple, the efficiency is high, and the cost is low.

As shown in fig. 1 and fig. 3, the first packaging layer 13 and the electrical connection layer 2 are encapsulated by the second packaging layer 5, and the second packaging layer 5 encapsulates the first packaging layer 13 and the electrical connection layer 2 to form a whole, so as to facilitate improving the binding force between the electrical connection layer 2 and the first packaging layer 13 and improving the stability of the electrical connection of the board-to-board connection structure 100.

The material of the second encapsulation layer 5 may be selected from any thermosetting material or photo-curing material having filling and protecting functions, such as a cover film (CVL), ink, pure glue, ABF resin, prepreg (PP), etc. Specifically, the material of the second encapsulation layer 5 may be ink.

As shown in fig. 1 and 3, the board-to-board connection structure 100 further includes a second functional module 50 disposed on a side of the substrate 11 facing away from the electronic component 12, where the second functional module 50 is electrically connected to the package substrate 1 a. Specifically, a plurality of solder balls 4 are disposed on a side of the substrate 11 facing away from the electronic component 12, and the package substrate 1a and the second module 50 are electrically connected through the plurality of solder balls 4. The functional module 4 may be a SIP module, a POP module, or another circuit board different from the first functional module 40. In this embodiment, the second functional module 50 is another circuit board different from the first functional module 40.

In the board-to-board connection structure 100 provided in this embodiment, the electrical connection between the electrical connection layer 2 and the connection pad 3 and the first functional module 40 is achieved by arranging the electrical connection layer in the packaging module 10, so that compared with directly soldering the BTB on the packaging substrate 1a, the layout area of the BTB is completely omitted, which is beneficial to reducing the weight and achieving the light, thin and short miniaturization of the electronic product. Moreover, the manufacturing process of the electrical connection layer 2 and the connection pad 3 is simple, the structure form of the existing packaging substrate 1 is not required to be changed, the cost is low, and the mass production is convenient.

Referring to fig. 6 and 7, a board-to-board connection structure 200 according to another embodiment of the present application is different from the board-to-board connection structure 100 according to the foregoing embodiment in that: the electrical connection layer 6 in the package module 20 in this embodiment is disposed on the side wall of the package substrate 1, and the specific structure of the electrical connection layer 6 is different from that of the electrical connection layer 2 in the foregoing embodiment.

The first encapsulation layer 13 of the encapsulation substrate 1b further comprises a side surface 133 connecting the first surface 131 and the second surface 132. The substrate 11 includes a substrate surface 111 disposed adjacent to the first encapsulation layer 13, and the first circuit layer 14 is disposed on the substrate surface 111. The substrate 11 is disposed beyond the side surface 133 of the first encapsulation layer 13, the side surface 133 and the substrate surface 111 define an accommodating space 17, the first circuit layer 14 extends to the accommodating space 17, and the electrical connection layer 6 is accommodated in the accommodating space 17 and is electrically connected with the first circuit layer 14. The connection pad 3 is disposed on a surface of the electrical connection layer 6 facing away from the side surface 133, and the first functional module 40 is electrically connected with the connection pad 3. By arranging the electrical connection layer 6 on the side surface 133 of the first encapsulation layer 13, the thickness of the encapsulation substrate 1b does not need to be increased, and the side space of the encapsulation substrate 1b is fully utilized, so that the space utilization rate of the encapsulation module 20 is improved, and the thickness of the encapsulation module 20 is reduced, so that the total thickness of the board-to-board connection structure 200 is reduced. In addition, by disposing the electrical connection layer 6 on the side surface of the first encapsulation layer 13, the connection pad 3 is led out from the side surface, so that the first functional module 40 is conveniently connected to the side surface of the encapsulation module 20, another possibility is provided for the connection of the first functional module 40, and the application range of the board-to-board connection structure 200 is expanded.

As shown in fig. 7 and 8, the electrical connection layer 6 includes a second circuit layer 61, a third circuit layer 62 disposed on a side of the second circuit layer 61 near the substrate 11, and a dielectric layer 64, and the second circuit layer 61 is embedded in the dielectric layer 64. The second circuit layer 61 is electrically connected to the third circuit layer 62, and the third circuit layer 62 is electrically connected to the first circuit layer 14, so as to electrically connect the electrical connection layer 6 to the first circuit layer 14. The second circuit layer 61 includes a first conductive line 611 disposed substantially perpendicular to the side surface 133 and a second conductive line 612 disposed substantially parallel to the side surface 133, the second conductive line 612 electrically connecting the first conductive line 611 and the third circuit layer 62, and an end of the first conductive line 611 facing away from the second conductive line 612 is exposed from a surface of the dielectric layer 64 facing away from the side surface 133. The connection pad 3 is electroplated on the end surface of the first wire 611 where the dielectric layer 64 is exposed. In this embodiment, the electrical connection layer 6 further includes a fourth circuit layer 63 disposed on a side of the second circuit layer 61 facing away from the third circuit layer 62, the third circuit layer 62 is electrically connected to the fourth circuit layer 63, and the electrical connection layer 6 may be a double-sided board. In this embodiment, the existing structure form of the package substrate 1b (for example, SIP module) is not required to be changed, the electrical connection layer 6 is only required to be added on the side surface of the package substrate 1b, and the manufacturing method of the electrical connection layer 6 adopts the conventional circuit board forming method, which is beneficial to simplifying the board-to-board connection process, reducing the cost and having strong adaptability. It should be understood that in other embodiments, the electrical connection layer 6 may be a single-sided board, and only the electrical connection between the second circuit layer 61 and the first circuit layer 14 may be implemented, which may be specifically designed according to actual needs.

As shown in fig. 6 and 7, the electrical connection layer 6 may be disposed on any side of the package substrate 1b according to actual needs. In other embodiments, it is understood that a plurality of the electrical connection layers 6 may be disposed on different sides of the package substrate 1, and the electrical connection layers 6 may be disposed on the upper surface or the lower surface of the package substrate 1 b. Therefore, in this embodiment, the connection pads 3 may be provided by the lead-out lines on different surfaces of the package substrate 1b, so as to achieve the purpose of connecting the first functional module 40 to any surface of the package substrate 1b, which is beneficial to improving the flexibility of the structural design of the board-to-board connection structure 200.

As shown in fig. 6, the second functional module 50 is a POP module, so that the board-to-board connection structure 200 is convenient for achieving multiple functions.

As shown in fig. 9, and referring to fig. 6, the structure of the connection pad 3 is specifically a strip structure with a certain length-diameter ratio, and the strip connection pad 3 can improve the stability of the electrical connection between the connection pad and the first functional module 40.

Compared with the foregoing embodiments, the package module 20 of the present embodiment can fully utilize the side space of the package substrate 1b without increasing the thickness of the package substrate 1b by disposing the electrical connection layer 6 on the side wall of the package substrate 1b, thereby being beneficial to improving the space utilization rate of the package module 20, reducing the thickness of the package module 20, further reducing the total thickness of the board-to-board connection structure 200, and being beneficial to reducing the thickness and the size of the board-to-board connection structure 200; moreover, the wires can be led out to different surfaces of the first packaging layer 13 according to actual needs to form the connection pad 3, so that connection between the packaging module 20 and the first functional module 40 is facilitated, another possibility is provided for connection of the first functional module 40, the application range of the board-to-board connection structure 200 is expanded, and the purpose that the first functional module 40 is connected to any surface of the packaging substrate 1b can be achieved, which is beneficial to improving flexibility of structural design of the board-to-board connection structure 200.

Referring to fig. 10, the board-to-board connection structure 300 according to another embodiment of the present application is substantially identical to the board-to-board connection structure 100 provided in the previous embodiment, except that: the substrate 11 is further provided with the electrical connection layer 6 on the side surface of the package substrate 1c, and details of the specific structure of the electrical connection layer 6 and how to provide the electrical connection layer 6 on the side surface of the package substrate 1c refer to the method for providing the electrical connection layer 6 in the board-to-board link structure 200 in the foregoing embodiment, which is not repeated herein.

In this embodiment, the package module 10 provided in the foregoing embodiment and the package module 20 provided in the foregoing embodiment are combined together, the electrical connection layer 2 is disposed on the upper surface of the package substrate 1c (i.e., the second surface 132 of the first package layer 13), and the electrical connection layer 6 is disposed on the side surface of the package substrate 1c (i.e., the side surface 133 of the first package layer 13), so that the purpose that the first functional module 40 is connected to any surface of the package substrate 1 can be achieved, which is beneficial to improving the flexibility of the structural design of the board-to-board connection structure 300.

An embodiment of the present application further provides a method for manufacturing the board-to-board connection structure 100, which includes the following steps.

S11: as shown in fig. 11, a package substrate 1a is provided, and the package substrate 1a includes a substrate 11, an electronic component 12 disposed on the substrate 11, a first package layer 13 disposed on the substrate 11 and encapsulating the electronic component 12, and a first circuit layer 14 disposed on a surface of the substrate 11 adjacent to the electronic component 12. The first encapsulation layer 13 comprises a first surface 131 arranged close to the substrate 11 and a second surface 132 arranged away from the substrate 11. The first encapsulation layer 13 is divided into an encapsulation area a for encapsulating the electronic component 12 and an edge area B located at the periphery of the encapsulation area a according to the distribution position of the electronic component 12, wherein the edge area B is not provided with the electronic component 12.

S12: as shown in fig. 12, the edge region B is perforated to form a plurality of through holes 15 penetrating the first surface 131 and the second surface 132.

The through holes 15 are formed by laser drilling or mechanical drilling, and a plurality of through holes 15 are distributed around the periphery of the packaging area a.

S13, as shown in fig. 13, a conductor 16 is disposed in the through hole 15, one end of the conductor 16 is electrically connected to the first circuit layer 14, and the other end of the conductor 16 is exposed from the second surface 132.

The conductor 16 is formed in the through hole 15 by electroplating or filling with a conductive paste.

S14, as shown in fig. 14, a second circuit layer 21 is formed on the second surface 132, where the second circuit layer 21 includes a first conductive line 211 disposed substantially parallel to the second surface 132 and a second conductive line 212 disposed substantially perpendicular to the second surface 132, and one end of the first conductive line 211 is electrically connected to one of the conductors 16, and the other end is electrically connected to the second conductive line 212.

As shown in fig. 15, a dielectric layer 22 is formed on the second surface 132, the second circuit layer 21 is embedded in the dielectric layer 22, and one end of the second conductive line 212 facing away from the first conductive line 211 is exposed from the surface of the dielectric layer 22 facing away from the second surface 132.

The electrical connection layer 2 is specifically formed by adopting a re-wiring technology (Redistribution Layer, RDL), and a part of the dielectric layer 22 is polished by polishing, so that the second conductive wire 212 is exposed from the surface of the dielectric layer 22, so that the connection pad 3 is disposed subsequently.

S16, as shown in fig. 3, a connection pad 3 is formed on the end surface of the second conductive line 212 where the dielectric layer 22 is exposed.

The connection pad 3 is formed on the end face of the second wire 212 by electroplating copper.

S17, as shown in fig. 1, a first functional module 40 is disposed on the connection pad 3, thereby obtaining the board-to-board connection structure 100.

The first functional module 40 may be a circuit board, in particular an FPC.

The first functional module 40 is connected to the connection pad 3 by means of anisotropic conductive adhesive or soldering.

In this embodiment, as shown in fig. 1 and fig. 3, the preparation method may further include: the second functional module 50 is connected to the package module 10, the second functional module 50 is disposed on a side of the substrate 11 away from the electronic component 12, and the second functional module 50 is electrically connected to the package substrate 1a through the solder balls 4. In particular, the second functional module 50 may be another circuit board distinct from the first functional module 40.

In this embodiment, as shown in fig. 1 and 3, after forming the electrical connection layer 2, the preparation method may further include: a second encapsulation layer 5 is formed on the surface of the substrate 11, and the first encapsulation layer 13 and the electrical connection layer 2 are embedded in the second encapsulation layer 5.

Another embodiment of the present application further provides a method for manufacturing the board-to-board connection structure 200, where the method for manufacturing the board-to-board connection structure 200 in this embodiment is different from the method for manufacturing the board-to-board connection structure 100 in the foregoing embodiment in that the following steps are performed:

As shown in fig. 16 and 17, S21, the first encapsulation layer 13 of the encapsulation substrate 1b includes the first surface 131, the second surface 132, and a side surface 133 connecting the first surface 131 and the second surface 132, and the electrical connection layer 6 is disposed on the side surface 133.

The substrate 11 includes a substrate surface 111 disposed adjacent to the first encapsulation layer 13, and the first circuit layer 14 is disposed on the substrate surface 111. The substrate 11 is disposed beyond the side surface 133 of the first encapsulation layer 13, the side surface 133 and the substrate surface 111 define an accommodating space 17, and the first circuit layer 14 extends to the accommodating space 17. The electrical connection layer 6 is disposed on the side surface 133 and is accommodated in the accommodating space 17, and the electrical connection layer 6 is electrically connected to the first circuit layer 14.

The electrical connection layer 6 and the first circuit layer 14 are electrically connected by soldering.

The specific manufacturing method of the electrical connection layer 6 is manufactured by adopting a conventional manufacturing method of a circuit board, and will not be described in detail herein.

S22, as shown in fig. 7, a connection pad 3 is formed on the electrical connection layer 6.

S23, as shown in fig. 6, the board-to-board connection structure 200 is formed by connecting the first functional module 40 to the connection pad 3.

Referring to fig. 10 in combination, still another embodiment of the present application further provides a method for manufacturing a board-to-board connection structure 300, where the method for manufacturing the board-to-board connection structure 300 in this embodiment is different from the method for manufacturing the board-to-board connection structure 100 and the board-to-board connection structure 200 in the foregoing embodiment in the following steps:

s31, the first encapsulation layer 13 of the encapsulation substrate 1c includes the first surface 131, the second surface 132, and a side surface 133 connecting the first surface 131 and the second surface 132, the substrate 11 includes a substrate surface 111 disposed adjacent to the first encapsulation layer 13, and the first circuit layer 14 is disposed on the substrate surface 111. The substrate 11 is disposed beyond the side surface 133 of the first encapsulation layer 13, the side surface 133 and the substrate surface 111 define an accommodating space 17, and the first circuit layer 14 extends to the accommodating space 17. Disposing an electrical connection layer 2 on the second surface 132, wherein the electrical connection layer 2 is electrically connected to the first circuit layer 14; another electrical connection layer 6 is disposed on the side surface 133, and the electrical connection layer 6 is accommodated in the accommodating space 17 and electrically connected to the first circuit layer 14.

And S32, forming connection pads 3 on the electric connection layer 2 and the electric connection layer 6 respectively.

S33, two first functional modules 40 are connected to the connection pads 3 on the electrical connection layer 2 and the electrical connection layer 6, respectively.

It will be appreciated that in other embodiments, after the formation of the electrical connection layer 2 is completed, the connection pad 3 may be directly formed on the electrical connection layer 2 and connected to the first functional module 40; after which an electrical connection layer 6 and a connection pad 3 on the electrical connection layer 6 are provided. The order of forming the electrical connection layer 2 and the electrical connection layer 6 can be changed according to actual needs.

It should be noted that the above is only a specific embodiment of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily think about changes or substitutions within the technical scope of the present application, and the changes or substitutions should be covered in the scope of the present application; in the case of no conflict, the embodiments of the present application and features of the embodiments may be combined with one another. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A package module, comprising:

a package substrate, comprising:

A substrate;

the first circuit layer is arranged on the substrate;

the electronic component is arranged on the substrate and is electrically connected with the first circuit layer;

the first packaging layer is positioned on the substrate and is used for packaging the electronic component and the first circuit layer, and comprises a first surface close to the substrate, a second surface far away from the first surface and a side surface connecting the first surface and the second surface;

the electric connection layer is arranged on the second surface and/or the side surface and is electrically connected with the first circuit layer; and

a plurality of connection pads arranged on the surface of the electric connection layer, which is away from the first packaging layer, and the connection pads are electrically connected with the electric connection layer,

the electrical connection layer is formed by a rewiring layer technology, the electrical connection layer is used for leading out the first circuit layer and rearranging the first circuit layer through the plurality of connection pads, the packaging matrix is electrically connected with the first functional module through the plurality of connection pads, and the first functional module comprises at least one of a circuit board and another packaging module.

2. The package module of claim 1, wherein the electrical connection layer is disposed on the second surface, the package substrate further includes a through hole penetrating through the first surface and the second surface, a conductor is disposed in the through hole, one end of the conductor is electrically connected to the first circuit layer, and the other end of the conductor is exposed on the second surface and is electrically connected to the electrical connection layer.

3. The package module of claim 2, wherein the first package layer includes a package region for packaging the electronic component and an edge region at a periphery of the package region, the via and the conductor being located at the edge region.

4. The package module according to claim 2, wherein the electrical connection layer includes a second circuit layer and a dielectric layer, the second circuit layer is embedded in the dielectric layer, the second circuit layer includes a first conductive wire and a second conductive wire, two ends of the first conductive wire are respectively electrically connected with the conductor and the second conductive wire, and one end of the second conductive wire, which is away from the first conductive wire, is exposed from a surface of the dielectric layer, which is away from the package substrate, and is electrically connected with the connection pad.

5. The package module of claim 1, wherein the substrate includes a substrate surface disposed adjacent to the first package layer, the first circuit layer is disposed on the substrate surface, the substrate is disposed beyond the side surface of the first package layer, the side surface and the substrate surface together define an accommodating space, the first circuit layer extends to the accommodating space, and the electrical connection layer is disposed on the side surface and is accommodated in the accommodating space.

6. The package module of claim 5, wherein the electrical connection layer comprises a second circuit layer, a third circuit layer disposed on a side of the second circuit layer adjacent to the substrate, and a dielectric layer, the second circuit layer is embedded in the dielectric layer, the third circuit layer is electrically connected to the first circuit layer, and the second circuit layer is electrically connected to the third circuit layer.

7. The package module of claim 6, wherein the second circuit layer includes a first conductive line and a second conductive line, the second conductive line is electrically connected to the third circuit layer and the first conductive line, respectively, and an end of the first conductive line facing away from the second conductive line is exposed from a surface of the dielectric layer facing away from the first package layer and is electrically connected to the connection pad.

8. The package module according to claim 1, wherein the number of the electrical connection layers is at least two, one electrical connection layer is disposed on the second surface, the package substrate further includes a through hole penetrating through the first surface and the second surface, a conductor is disposed in the through hole, one end of the conductor is electrically connected to the first circuit layer, and the other end of the conductor is exposed on the second surface and is electrically connected to the electrical connection layer;

the side surface is provided with another electric connection layer, the base plate is including being close to the base plate surface that first encapsulation layer set up, first circuit layer set up in the base plate surface, the base plate surpasses first encapsulation layer the side surface sets up, the side surface with the base plate surface encloses into an accommodation space jointly, first circuit layer extends to accommodation space, another electric connection layer set up in the side surface and hold in accommodation space.

9. The packaging module of claim 1, further comprising a second packaging layer that encapsulates the first packaging layer and the electrical connection layer.

10. A board-to-board connection structure, comprising the package module of any one of claims 1 to 9 and a first functional module, wherein the first functional module is disposed on the connection pad and is electrically connected to the package substrate through the connection pad and the electrical connection layer.

11. The board-to-board connection structure according to claim 10, wherein a connection layer is disposed between the connection pad and the first functional module, and the connection layer includes anisotropic conductive adhesive or solder paste.

12. The board-to-board connection structure of claim 10, further comprising a second functional module disposed on a side of the substrate facing away from the electronic component, the second functional module being electrically connected to the package substrate.

13. A terminal comprising a housing and a board-to-board connection structure accommodated in the housing, the board-to-board connection structure being the board-to-board connection structure according to any one of claims 10 to 12.

14. The preparation method of the packaging module is characterized by comprising the following steps:

providing a packaging substrate, wherein the packaging substrate comprises a substrate, a first circuit layer arranged on the substrate, an electronic component arranged on the substrate and electrically connected with the first circuit layer, and a first packaging layer which is arranged on the substrate and packages the electronic component and the first circuit layer, and the first packaging layer comprises a first surface close to the substrate, a second surface far away from the first surface and a side surface connecting the first surface and the second surface;

Forming an electrical connection layer on the second surface and/or the side surface, wherein the electrical connection layer is electrically connected with the first circuit layer; and

a plurality of connection pads are arranged on the surface of the electric connection layer, which is away from the first packaging layer, and the connection pads are electrically connected with the electric connection layer, so that the packaging module is obtained,

15. The method of claim 14, wherein the first package layer includes a package region for packaging the electronic component and an edge region at a periphery of the package region,

the preparation method further comprises the steps of, before forming the electric connection layer:

punching the edge area to form a through hole, wherein the through hole penetrates through the first surface and the second surface; and

forming a conductor in the through hole, wherein the conductor is electrically connected with the first circuit layer, and one end of the conductor, which is away from the first circuit layer, is exposed from the second surface;

After the conductors are formed, the preparation method of the electric connection layer comprises the following steps:

forming a second circuit layer on the second surface, wherein the second circuit layer comprises a first wire and a second wire, and two ends of the first wire are respectively and electrically connected with the conductor and the second wire; and

and forming a dielectric layer on the second surface, wherein the second circuit layer is embedded in the dielectric layer, and one end of the second wire, which is away from the first wire, is exposed from the surface of the dielectric layer, so that the electric connection layer is obtained.

16. The method of claim 14, wherein the substrate includes a substrate surface disposed adjacent to the first encapsulation layer, the first circuit layer is disposed on the substrate surface, the substrate is disposed beyond the side surface of the first encapsulation layer, the side surface and the substrate surface together define an accommodating space, the first circuit layer extends to the accommodating space, and the electrical connection layer is disposed on the side surface and is accommodated in the accommodating space.

17. The method of manufacturing a package module according to claim 14, wherein after forming the electrical connection layer, the method further comprises:

And forming a second packaging layer on the surface of the substrate so that the first packaging layer and the electric connection layer are embedded in the second packaging layer.

18. The preparation method of the board-to-board connection structure is characterized by comprising the following steps:

providing the packaging module of any one of claims 1 to 9;

forming a connection layer on the connection pad; and

providing a first functional module, and arranging the first functional module on the connecting layer so as to obtain the board-to-board connecting structure.

19. The method of manufacturing a board-to-board connection according to claim 18, wherein the connection layer comprises anisotropic conductive paste or solder paste.

20. The method of manufacturing a board-to-board connection structure according to claim 18, further comprising:

and a second functional module is arranged on one side of the substrate, which is away from the first circuit layer, and the second functional module is electrically connected with the first circuit layer.