Circuit board structure and method for manufacturing same, and signal transmission assembly and data center

Abstract

The present application relates to the technical field of circuit boards. Provided in the embodiments of the present application is a circuit board structure (100), comprising: a first circuit board (10), which comprises a plurality of signal lines (131); and a plurality of connection structures (21), which protrude from the surface of the first circuit board (10), wherein each connection structure (21) is electrically connected to one corresponding signal line (131), and the plurality of connection structures (21) are further used for electrically connecting to a second circuit board (30), such that the plurality of signal lines (131) are electrically connected to the second circuit board (30). In the circuit board structure provided in the embodiments of the present application, a first circuit board and connection structures protruding from the surface of the first circuit board can replace high‑speed coaxial cables and connectors, thereby saving space. Further provided in the embodiments of the present application are a method for manufacturing a circuit board structure, and a signal transmission assembly and a data center.

Description

Circuit board structure and manufacturing method thereof, signal transmission assembly and data center

[0001] The present application claims priority to the Chinese patent application No. 202411391853.2, filed on September 30, 2024, and entitled "Circuit board structure and manufacturing method thereof, signal transmission assembly and data center", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0002] The present application relates to the technical field of circuit boards, and in particular to a circuit board structure and manufacturing method thereof, a signal transmission assembly and a data center. BACKGROUND

[0003] Electronic devices such as servers and switches include multiple functional modules. Existing data centers usually use high-speed coaxial cables to connect different functional modules.

[0004] With the development of technology, the speed of each functional module gradually increases, and the number of high-speed coaxial cables and connectors that need to be arranged in the data center also increases, and the high-speed coaxial cables and connectors occupy a lot of space. SUMMARY

[0005] The present application aims to provide a circuit board structure and manufacturing method thereof, a signal transmission assembly and a data center, which solve the problem of high-speed coaxial cables and connectors occupying a lot of space.

[0006] An embodiment of the first aspect of the present application provides a circuit board structure, which comprises a first circuit board comprising a plurality of signal lines; a plurality of connection structures protruding from the surface of the first circuit board, each of the connection structures being electrically connected to a corresponding signal line; and the plurality of connection structures are also used to electrically connect to a second circuit board, so that the plurality of signal lines are electrically connected to the second circuit board.

[0007] The circuit board structure provided by the embodiment of the present application comprises a first circuit board and a plurality of connection structures. The first circuit board comprises a plurality of signal lines, which can transmit signals respectively. The first circuit board replaces a plurality of high-speed coaxial cables. The first circuit board can be connected to a second circuit board through the plurality of connection structures protruding from the surface of the first circuit board, i.e. the first circuit board does not need to be connected to the second circuit board through a coaxial connector. The circuit board structure provided by the embodiment of the present application replaces the high-speed coaxial cables through the first circuit board, and the circuit board structure also omits the coaxial connector, thereby saving space.

[0008] In some embodiments, the first circuit board comprises a first outer metal layer, a second outer metal layer, and at least one inner metal layer between the first outer metal layer and the second outer metal layer, the signal line is a line in the inner metal layer; the first outer metal layer comprises a plurality of first pads, the first pads are correspondingly connected with the signal line, the connecting structure is connected with the first pad and electrically connected, and the connecting structure is protrudingly arranged relative to the first pad.

[0009] In some embodiments, the circuit board structure further comprises an adapter circuit board, the adapter circuit board comprises a first surface and a second surface arranged oppositely, the plurality of connecting structures comprises a plurality of first connecting structures protrudingly arranged on the first surface and a plurality of second connecting structures protrudingly arranged on the second surface, the first connecting structures and the second connecting structures are electrically connected one by one; the second connecting structure is connected with the first pad and electrically connected, and the first connecting structure is used for electrically connecting with the second circuit board.

[0010] In some embodiments, the adapter circuit board is adhered to the first circuit board by ACF conductive adhesive, or the adapter circuit board is fixed to the first circuit board by welding.

[0011] In some embodiments, the adapter circuit board is provided with a plurality of through holes filled with conductive material, and the first connecting structure and the second connecting structure are respectively covered on opposite sides of the through hole and conduct through the through hole.

[0012] In some embodiments, the conductive material in the through hole is hole copper, the first connecting structure comprises a first base copper part and a first electroplated copper part integrated with the hole copper, and the second connecting structure comprises a second base copper part and a second electroplated copper part integrated with the hole copper.

[0013] In some embodiments, the height of the first connecting structure is 60 μm-90 μm; and / or, the height of the second connecting structure is 60 μm-90 μm.

[0014] Embodiments of the second aspect of the application propose a manufacturing method of a circuit board structure, comprising: providing a first circuit board, the first circuit board comprising a plurality of signal lines; manufacturing a plurality of connecting structures, the connecting structures being protrudingly arranged on the surface of the first circuit board and electrically connected to a corresponding signal line, wherein the connecting structures are also used for electrically connecting with a second circuit board, so that the plurality of signal lines are electrically connected with the second circuit board.

[0015] The circuit board structure manufactured by the manufacturing method replaces the high-speed coaxial cable and omits the coaxial connector, so that the circuit board structure has simple structure and small size, and occupies less space, and the manufacturing method has high manufacturing efficiency and low cost.

[0016] In some embodiments, the manufacturing the plurality of connection structures comprises: manufacturing a transition circuit board, wherein the transition circuit board comprises a first surface and a second surface arranged oppositely, the plurality of connection structures comprises a plurality of first connection structures protruding from the first surface and a plurality of second connection structures protruding from the second surface, and the first connection structures and the second connection structures are electrically connected one by one; and the transition circuit board is fixedly connected to the first circuit board, so that the second connection structures are electrically connected to the signal lines.

[0017] In some embodiments, the manufacturing the transition circuit board comprises: providing a base material, wherein the base material comprises a dielectric layer and base copper layers arranged on both sides of the dielectric layer; drilling a plurality of through holes in the base material; plating copper on the base material to fill hole copper in the through holes and form a copper plating layer on the surface of the base material; and etching the base material to form a plurality of protruding first connection structures and second connection structures on the opposite surfaces of the dielectric layer, respectively, and the first connection structures and the second connection structures are electrically connected through the hole copper.

[0018] In some embodiments, the fixing and connecting the transition circuit board between the first circuit board and the second circuit board comprises: bonding the transition circuit board to the first circuit board by ACF conductive adhesive, wherein the second surface faces the first circuit board; and pressing the transition circuit board, the ACF conductive adhesive, and the first circuit board.

[0019] Embodiments of the third aspect of the present application provide a signal transmission assembly, comprising a circuit board structure provided by the first aspect or the second aspect, the circuit board structure comprising a first circuit board and a plurality of connection structures arranged at opposite ends of the first circuit board, and the first circuit board comprising a plurality of signal lines; a second circuit board connected to a head end of the signal lines through the connection structure at one end of the first circuit board; and a third circuit board connected to a tail end of the signal lines through the connection structure at the other end of the first circuit board.

[0020] Embodiments of the fourth aspect of the present application provide a data center comprising a circuit board manufactured by the manufacturing method of the first aspect or the second aspect, or a signal transmission assembly of the third aspect.

[0021] The above description is only a summary of the technical solutions of the present application. In order to make the technical means of the present application more clearly understood and implemented according to the content of the description, and in order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the following will specifically describe the embodiments of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment or prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without any creative labor.

[0023] Fig. 1A is a structural schematic diagram of a terminal device in the prior art;

[0024] Fig. 1B is a schematic diagram of the connection between a high-speed coaxial cable and a circuit board module in the prior art;

[0025] Fig. 2 is a structural schematic diagram of a signal transmission assembly provided by an embodiment of the present application;

[0026] Fig. 3 is a sectional schematic diagram of the signal transmission assembly provided by an embodiment of the present application along the line A-A in Fig. 2;

[0027] Fig. 4 is a sectional schematic diagram of the signal transmission assembly provided by another embodiment of the present application along the line A-A in Fig. 2;

[0028] Fig. 5 is a structural schematic diagram of a circuit board structure provided by an embodiment of the present application;

[0029] Fig. 6 is a structural schematic diagram of a conversion circuit board provided by an embodiment of the present application;

[0030] Fig. 7 is a sectional schematic diagram of a first circuit board provided by an embodiment of the present application;

[0031] Fig. 8 is a sectional schematic diagram of a first circuit board provided by another embodiment of the present application;

[0032] Fig. 9 is a schematic diagram of an inner layer circuit in a first circuit board provided by an embodiment of the present application;

[0033] Fig. 10 is a top view of a conversion circuit board provided by an embodiment of the present application;

[0034] Fig. 11 is a flowchart of a manufacturing method of a circuit board structure provided by an embodiment of the present application;

[0035] Fig. 12 is a flowchart of a manufacturing method of a circuit board structure provided by an embodiment of the present application;

[0036] Fig. 13A to Fig. 13D are schematic diagrams of a manufacturing process of a conversion circuit board according to an embodiment of the present application;

[0037] Fig. 14 is a schematic diagram of the assembly of a first circuit board and ACF conductive adhesive according to an embodiment of the present application;

[0038] Fig. 15 is a schematic diagram of the assembly of a first circuit board, ACF conductive adhesive and a conversion circuit board according to an embodiment of the present application;

[0039] Fig. 16 is a schematic diagram of the assembly of a circuit board structure and ACF conductive adhesive according to an embodiment of the present application;

[0040] Fig. 17 is a schematic diagram of the assembly of a circuit board structure, ACF conductive adhesive and a second circuit board according to an embodiment of the present application.

[0041] Main element symbol explanation:

[0042] 100, circuit board structure; 10, first circuit board; 11, first outer metal layer; 111, first pad; 12, second outer metal layer; 13, inner metal layer; 131, signal line; 131a, differential signal line; 131b, single-ended signal line; 14, insulating medium layer; 15, cover film; 16, solder mask layer; 17, adhesive layer; 171, non-windowed portion; 172, windowed portion; 20, conversion circuit board; 20a, first surface; 20b, second surface; 21, connection structure; 211, first connection structure; 2111, first base copper portion; 2112, first electroplated copper portion; 212, second connection structure; 2121, second base copper portion; 2122, second electroplated copper portion; 22, circuit board body; 23, hole copper; 201, medium layer; 202, base copper layer; 203, plated copper layer; 204, via hole; 205, dry film; 30, second circuit board; 31, second pad; 40, third circuit board; 50, ACF conductive adhesive; 51, conductive particle; 1, circuit board module; 2, high-speed coaxial cable; 3, coaxial connector. DETAILED DESCRIPTION

[0043] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and should not be used to limit the present application.

[0044] It is to be noted that when a component is referred to as being "on" or "set on" another component, it can be directly or indirectly on the other component. When a component is referred to as being "connected to" another component, it can be directly or indirectly connected to the other component. The terms "upper", "lower", "left", "right", and the like indicate the orientation or position shown in the drawings and are used for convenience only in describing the application, and are not intended to indicate or imply absolute directions, orientations, or positions, and are not intended to limit the application to a particular orientation, configuration, or use, and thus can not be construed as limiting the application. The terms "first", "second", and the like are used only for convenience and are not intended to indicate or imply relative importance or a required numbering of technical features. The term "plurality" means two or more, unless otherwise expressly specified and limited.

[0045] In the description of the embodiments of the present application, unless otherwise explicitly specified and limited, the technical terms "mounting", "connection", "linking", "fixing" and the like should be understood in a broad sense, for example, can be fixed connection, can also be detachable connection, or integral; can be mechanical connection, can also be electrical connection; can be direct connection, can also be indirect connection through an intermediate medium, can be internal communication of two elements or interaction relationship between two elements. For those skilled in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0046] In the description of the embodiments of the present application, the reference to "one embodiment", "some embodiments" or "embodiments" means that the specific features, structures or characteristics described in connection with the embodiment are included in one or more embodiments of the present application. Therefore, the statements "in one embodiment", "in some embodiments", "in other some embodiments", "in other some embodiments" and the like appearing in different places in the specification are not necessarily all referring to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized. In addition, in one or more embodiments, specific features, structures or characteristics can be combined in any suitable manner.

[0047] Electronic devices such as servers and switches are usually connected by cables. FIG. 1A is a structural schematic diagram of a terminal device in the prior art, and FIG. 1B is a connection schematic diagram of a high-speed coaxial cable and a circuit board module in the prior art. As shown in FIG. 1A, different circuit board modules 1 are connected by high-speed coaxial cables 2 in the terminal device. As shown in FIG. 1B, the two ends of the high-speed coaxial cable 2 are respectively connected with coaxial connectors 3, and the coaxial connectors 3 are screwed on the circuit board module 1 to connect the high-speed coaxial cable 2 with the circuit board module 1. With the development of technology, the speed of each functional module is gradually increased, and the number of high-speed coaxial cables 2 required to be arranged in the cabinet of the electronic device is gradually increased. The high-speed coaxial cable 2 and the coaxial connector 3 occupy a large space, resulting in insufficient space in the cabinet.

[0048] Therefore, an embodiment of the present application provides a circuit board structure. The circuit board structure includes a first circuit board and a plurality of connection structures. The first circuit board includes a plurality of signal lines arranged side by side. The plurality of connection structures are protruded from the surface of the first circuit board. The plurality of connection structures are respectively electrically connected with the signal lines, and the plurality of connection structures are further used to electrically connect with a second circuit board, so that the plurality of signal lines are electrically connected with the second circuit board. In this way, the first circuit board can transmit signals by using the plurality of signal lines, so that the first circuit board replaces the plurality of high-speed coaxial cables. The first circuit board is connected with the second circuit board by the connection structures, that is, the first circuit board does not need to be connected with another circuit board by the coaxial connector. The circuit board structure provided by the embodiment of the present application replaces the high-speed coaxial cable and omits the coaxial connector by using the first circuit board and the plurality of connection structures, thereby saving the space and being beneficial to reducing the size of the electronic device.

[0049] The circuit board structure in the embodiment of the present application can be applied to a data center, and the circuit board structure can connect different devices in the data center.

[0050] An embodiment of the first aspect of the present application provides a circuit board structure. Referring to FIGS. 2 to 9, the circuit board structure 100 includes a first circuit board 10 and a plurality of connection structures 21. The first circuit board 10 includes a plurality of signal lines 131, and the plurality of connection structures 21 are protruded from the surface of the first circuit board 10. The connection structure 21 is respectively electrically connected with a corresponding signal line 131. The plurality of connection structures 21 are further used to electrically connect with a second circuit board 30, so that the plurality of signal lines 131 are electrically connected with the second circuit board 30.

[0051] Referring to FIG. 7, the first circuit board 10 is a multilayer circuit board, preferably a flexible printed circuit (FPC), which has the advantages of high wiring density, light weight, thin thickness, and good bending resistance, and can be conveniently connected between two circuit boards for easy assembly. In other embodiments, the first circuit board 10 can also be a rigid circuit board or a rigid-flexible combined board.

[0052] The first circuit board 10 includes a plurality of spaced-apart signal lines 131, which can be arranged in parallel or non-parallel. The signal lines 131 can extend along the length direction of the first circuit board 10, wherein the signal lines 131 can be straight lines, or the ends of the signal lines 131 can be bent to extend to meet the actual assembly requirements. In addition, the first circuit board 10 is a multilayer circuit board, and the signal lines 131 can be arranged in the same metal layer of the first circuit board 10 or in different metal layers. In some embodiments, the plurality of signal lines 131 all extend along the length direction of the first circuit board 10.

[0053] The signal lines 131 can be high-speed signal lines or low-speed signal lines. The number of signal lines 131 is two or more, and the plurality of signal lines 131 include at least one of a differential signal line 131a including two differential traces and a single-ended signal line 131b. Optionally, a ground line can be arranged between two adjacent groups of signal lines 131, which can isolate the two adjacent groups of signal lines 131 and shield the crosstalk between the adjacent signal lines 131.

[0054] The connection structure 21 is a conductive structure protruding from the surface of the first circuit board 10. Optionally, the connection structure 21 is a solder pad, a combination of a reinforcing member and a solder pad, a copper pillar, or the like. As shown in FIG. 3, in some embodiments, a plurality of connection structures 21 can be directly fabricated on the first circuit board 10, i.e., the connection structure 21 and the first circuit board 10 are an integral structure, and the connection structure 21 can be a boss structure fabricated through a copper layer on the first circuit board 10 or a cured conductive carbon oil structure, or the like. As shown in FIG. 4, in other embodiments, a plurality of connection structures 21 can be fabricated on the adapter circuit board 20, and the adapter circuit board 20 is connected to the first circuit board 10, so that the connection structure 21 protrudes from the surface of the first circuit board 10. The adapter circuit board 20 further includes a circuit board body 22, and the connection structure 21 protrudes from the circuit board body 22. Exemplarily, the circuit board body 22 includes a dielectric layer. It can be understood that the circuit board body 22 can also include at least one dielectric layer and at least one copper layer.

[0055] The signal line 131 has a head end and a tail end, and the head end and the tail end of the signal line 131 are respectively connected with the connecting structure 21, and the second circuit board 30 can be connected to the head end or the tail end of the signal line 131 through the connecting structure 21. For example, the head end of the signal line 131 is electrically connected to the second circuit board 30 through the connecting structure 21, and the tail end of the signal line 131 is electrically connected to the third circuit board 40 through the connecting structure 21. It can be understood that in other embodiments, one of the head end and the tail end of the signal line 131 is connected to the second circuit board 30 through the connecting structure 21, and the other one of the head end and the tail end can also be connected to the third circuit board 40 through other types of connecting structures.

[0056] The second circuit board 30 and the third circuit board 40 can be a circuit board module composed of a plurality of circuit boards or a single circuit board, and optionally, the second circuit board 30 and the third circuit board 40 are circuit board modules in a data center.

[0057] The circuit board structure 100 provided by the embodiments of the present application includes the first circuit board 10 and a plurality of connecting structures 21, the first circuit board 10 includes a plurality of signal lines 131, and the plurality of signal lines 131 can be used to respectively transmit signals, and the first circuit board 10 replaces a plurality of high-speed coaxial cables; the first circuit board 10 is connected to the second circuit board 30 through the plurality of connecting structures 21 protruding from the surface of the first circuit board 10, that is, the first circuit board 10 does not need to be connected to the second circuit board 30 through a coaxial connector. The circuit board structure 100 provided by the embodiments of the present application replaces the high-speed coaxial cable through the first circuit board 10, and the circuit board structure 100 also omits the coaxial connector, thereby saving space.

[0058] Please refer to FIGS. 2 to 9, in some embodiments, the first circuit board 10 includes a first outer metal layer 11, a second outer metal layer 12, and at least one inner metal layer 13 arranged between the first outer metal layer 11 and the second outer metal layer 12, the signal line 131 is a circuit in the inner metal layer 13, the first outer metal layer 11 includes a plurality of first pads 111, each first pad 111 is electrically connected to a signal line 131, and the connecting structure 21 is connected to the first pad 111 and electrically connected, and the connecting structure 21 is protrudingly arranged relative to the first pad 111.

[0059] The first circuit board 10 is a multi-layer circuit board, and the first circuit board 10 includes at least three metal layers, and the plurality of metal layers are arranged in a stacking manner along the thickness direction of the first circuit board 10, and an insulating medium layer 14 is arranged between adjacent metal layers. For example, as shown in FIG. 7, the first circuit board 10 includes one inner metal layer 13, and it can be understood that the number of the inner metal layer 13 can also be two or more.

[0060] The first circuit board 10 is made of a plurality of sub-boards stacked, which can be flexible copper clad laminate (FCCL), copper foil, etc. The flexible copper clad laminate refers to the copper clad laminate formed by bonding the copper foil to the single side or double side of the flexible insulating material such as polyester film or polyimide film through a certain process. The dielectric layer in the flexible copper clad laminate serves as the insulating dielectric layer 14 in the first circuit board 10, and the copper foil in the flexible copper clad laminate serves as the metal layer in the first circuit board 10; the adjacent sub-boards are provided with a glue layer 17. Optionally, the glue layer 17 is a high-frequency pure glue layer, which refers to a special glue film material used in high-frequency circuits or high-speed transmission lines, and has the characteristics of low dielectric constant and dielectric loss, excellent resistance to heat soldering, etc. These characteristics enable the high-frequency pure glue layer to maintain the integrity and stability of the signal in high-frequency and high-speed signal transmission.

[0061] In the design, the multiple high-speed coaxial cables with similar plug-in ports or connection ports can be replaced by the signal lines 131 designed on a circuit board, that is, the first circuit board 10 is used instead of the multiple high-speed coaxial cables. Optionally, the number of signal lines 131 is greater than 2 groups, and each group of signal lines 131 includes one or more signal lines 131.

[0062] Optionally, the two sides of each group of signal lines 131 are provided with ground lines, and the ground lines on the two sides of the signal lines 131 can play an isolation and shielding effect in the direction parallel to the board surface of the first circuit board 10, that is, to isolate and shield other factors from the electromagnetic interference of the signal lines 131. Specifically, a ground line is arranged between the two adjacent groups of signal lines 131, and a ground line is arranged on each side of the signal line whole formed by the plurality of signal lines 131, so as to play a good shielding and isolation effect.

[0063] Optionally, the first outer metal layer 11 and the second outer metal layer 12 are reference layers of the signal lines 131, and provide signal return paths for the signal lines 131. The signal lines 131 are used to transmit signals from a signal sending end to a signal receiving end, and in order to realize a signal return path, a reference layer is needed to return the signals. The first outer metal layer 11 and the second outer metal layer 12 are the outermost metal layers on both sides of the first circuit board 10, that is, the top metal layer and the bottom metal layer of the first circuit board 10, and the first outer metal layer 11 and the second outer metal layer 12 can shield and isolate the plurality of signal lines 131 in a direction perpendicular to the first circuit board 10. Optionally, the first outer metal layer 11 and the second outer metal layer 12 each include a plurality of reference ground lines, each of which corresponds to and is stacked with a signal line 131; or the first outer metal layer 11 and the second outer metal layer 12 are provided with a copper skin covering the plurality of signal lines 131. In other embodiments, when the inner metal layer 13 has multiple layers, one of the inner metal layers 13 between the first outer metal layer 11 and the signal lines 131 can also be used as a reference layer of the signal lines 131, and / or one of the inner metal layers 13 between the second outer metal layer 12 and the signal lines 131 can also be used as a reference layer of the signal lines 131.

[0064] As shown in FIGS. 7 and 9, the first outer metal layer 11 includes a plurality of first pads 111, and the leading end and the trailing end of each signal line 131 are electrically connected to a first pad 111.

[0065] In some embodiments, the first outer metal layer 11 is provided with a cover film 15 and a solder resist layer 16, and the solder resist layer 16 is windowed at positions corresponding to the first pads 111 to expose the first pads 111, thereby facilitating electrical connection between the first pads 111 and the connecting structure 21. The cover film 15 and the solder resist layer 16 are both used to cover the first outer metal layer 11, and the solder resist layer 16 is optionally disposed above the first pads 111 and windowed to expose the first pads 111, and the cover film 15 covers the remaining area of the board surface.

[0066] The connecting structure 21 is connected to and in electrical conduction with the first pads 111. The connecting structure 21 and the first pads 111 are connected to each other by welding, bonding or other methods, and the connecting structure 21 is also in electrical conduction with the first pads 111, that is, the connecting structure 21 is electrically connected to the first pads 111.

[0067] Optionally, the orthographic projection of the connecting structure 21 on the first circuit board 10 falls within the contour of the first pad 111, i.e. the cross-sectional area of the connecting structure 21 is less than or equal to the cross-sectional area of the first pad 111, and the connecting structure 21 is arranged opposite to the first pad 111, so that the connecting structure 21 can abut against the first pad 111 via the window of the anti-solder layer 16. It can be understood that in other embodiments, the cross-sectional area of the connecting structure 21 can also be greater than the cross-sectional area of the first pad 111.

[0068] Exemplarily, the first outer metal layer 11 includes a base copper layer and a plated copper layer. In the manufacturing process, a blind hole is first formed through the base copper layer, then the blind hole is filled by plating copper to form a first plated copper layer on the surface of the base copper layer, and then the first plated copper layer and the first base copper layer are patterned to form a plurality of first pads 111, which are electrically connected to the ends of the signal lines 131 through the blind holes.

[0069] In the circuit board structure 100 provided by the embodiments of the present application, the plurality of signal lines 131 are arranged in the inner metal layer 13, and the first outer metal layer 11 and the second outer metal layer 12 of the first circuit board 10 can provide isolation and shielding protection for the signal lines 131; the plurality of first pads 111 are arranged in the first outer metal layer 11, the first pads 111 are connected to the signal lines 131, and the connecting structure 21 is connected to the first pads 111, so that the signal lines 131 can be electrically connected to the second circuit board 30 through the first pads 111 and the connecting structure 21.

[0070] Please refer to FIG. 8 and FIG. 9, along the thickness direction (Z direction) of the first circuit board 10, the adhesive layer 17 can be arranged on one side or both sides of the signal lines 131. In some embodiments, along the extension direction (X direction) of the signal lines 131, the adhesive layer 17 includes a plurality of alternating non-windowed portions 171 and windowed portions 172, and the projection of the windowed portions 172 on the inner metal layer 13 covers the plurality of signal lines 131 along the width direction (Y direction) of the first circuit board 10. Optionally, the windowed portions 172 extend to opposite ends of the first circuit board 10 along the width direction thereof.

[0071] The windowing portion 172 is a hollowed area penetrating through the adhesive layer 17, and the windowing portion 172 can be made by drilling, punching, or the like. The non-windowing portion 171 can play a bonding role, and the first circuit board 10 can form a ground hole connecting the reference layer and the ground wire at the non-windowing portion 171. The first circuit board 10 forms an air layer at the position of the windowing portion 172, that is, the first circuit board 10 forms a suspended layered structure at the position of the windowing portion 172 of the adhesive layer 17. The dielectric loss (Dissipation Factor, DF) value of air is the lowest and slightly equal to 0; the DF value of the existing insulating medium layer in the FPC industry is usually between 0.006 and 0.001, and therefore, by adding an air layer in the medium layer between the signal line 131 and the reference layer, the DF value of the entire medium layer can be reduced, and the smaller the DF value is, the smaller the signal loss is.

[0072] The embodiment of the present application provides the windowing portion 172 in the adhesive layer 17, and an air layer can be formed at the position of the windowing portion 172, so that the signal loss of the signal line 131 is effectively reduced, and the signal transmission quality of the first circuit board 10 is improved. Meanwhile, the signal loss affects the transmission rate, and in the case that the length of the signal line 131 is relatively long, if the signal loss of the signal line 131 is relatively large, the transmission rate of the signal line 131 may not meet the use requirement; in the embodiment of the present application, the windowing portion 172 in the adhesive layer 17 reduces the signal loss of the signal line 131, and the circuit board structure 100 provided by the embodiment of the present application solves the problem that the signal line is too long to cause the transmission rate to be unable to meet the use requirement, and the replaceability of the first circuit board 10 is improved.

[0073] Please refer to FIGS. 2, 4 to 9, in some embodiments, the circuit board structure 100 further includes a conversion circuit board 20, the conversion circuit board 20 includes oppositely arranged first and second surfaces 20a and 20b, a plurality of connection structures 21 include a plurality of first connection structures 211 protruding from the first surface 20a and a plurality of second connection structures 212 protruding from the second surface 20b, the first connection structures 211 and the second connection structures 212 are electrically connected one by one; the second connection structure 212 is connected with the first pad 111 and is electrically connected, and the first connection structure 211 is used for electrically connecting with the second circuit board 30.

[0074] The conversion circuit board 20 is used for electrically connecting the first circuit board 10 with another circuit board, so that the signal line 131 can realize signal transmission with another circuit board. In some embodiments, the first circuit board 10 is respectively provided with two conversion circuit boards 20, one conversion circuit board 20 is connected between the first circuit board 10 and the second circuit board 30, and the other conversion circuit board 20 is connected between the first circuit board 10 and the third circuit board 40.

[0075] The first connection structure 211 on the first surface 20a of the adapter circuit board 20 is connected to the second circuit board 30, and the second connection structure 212 on the second surface 20b is connected to the signal line 131 on the first circuit board 10 through the first solder pad 111, so that the adapter circuit board 20 can electrically connect the signal line 131 and the second circuit board 30, and the adapter circuit board 20 replaces the coaxial connector.

[0076] The adapter circuit board 20 can be a flexible circuit board or a rigid circuit board. If the adapter circuit board 20 is a flexible circuit board, the base material of the adapter circuit board 20 can be PI (polyimide), LCP (liquid crystal polymer), or PTFE (polytetrafluoroethylene), and the adapter circuit board 20 is soft and resistant to bending. If the adapter circuit board 20 is a rigid circuit board, the base material can be composed of epoxy resin and glass cloth, and the adapter circuit board 20 has rigidity, is not bendable, and has better support strength.

[0077] Please refer to FIGS. 4-6, the first surface 20a of the adapter circuit board 20 faces the second circuit board 30, and a plurality of first connection structures 211 are protruding on the first surface 20a; the second surface 20b faces the first circuit board 10, and a plurality of second connection structures 212 are protruding on the second surface 20b, and the first connection structure 211 and the second connection structure 212 are both protruding relative to the surface of the adapter circuit board 20, so as to facilitate connection with the first circuit board 10 and the second circuit board 30. The first connection structure 211 and the second connection structure 212 are both conductive structures, such as copper pillars, silver pillars, or solidified conductive carbon oil. The first connection structure 211 and the second connection structure 212 can be the same structure or different structures.

[0078] The first connection structure 211 and the second connection structure 212 are one-to-one corresponding and electrically conductive, so that the adapter circuit board 20 can connect a plurality of signal lines 131 to another circuit board. For example, as shown in FIG. 5, the first connection structure 211 and the second connection structure 212 are conductive through the metallized through holes, and it can be understood that the first connection structure 211 and the second connection structure 212 can also be conductive through the lines on the adapter circuit board 20; the first connection structure 211 and the second connection structure 212 can be arranged in a straight line or staggered, as long as the first connection structure 211 and the second connection structure 212 are one-to-one corresponding and conductive. In this way, the adapter circuit board 20 is connected between the first circuit board 10 and the second circuit board 30, so that the signal line 131 on the first circuit board 10 can be electrically connected to the second circuit board 30 through the first connection structure 211 and the second connection structure 212 to realize signal transmission.

[0079] The circuit board structure 100 provided by the embodiment of the present application replaces the traditional high-speed coaxial cable and coaxial connector with the first circuit board 10 and the adapter circuit board 20, the thickness of the first circuit board 10 and the adapter circuit board 20 is thinner and the volume is smaller, the line integration degree is high, the space is effectively saved, and the cost is reduced; meanwhile, the adapter circuit board 20 is electrically connected to the first circuit board 10, compared with the mode that the coaxial connector is connected to the high-speed coaxial cable, the signal loss is reduced, and the structure is also simpler. The circuit board structure 100 provided by the embodiment of the present application solves the problem that the existing high-speed coaxial cable and coaxial connector occupy more space of the equipment, solves the problem of high cost of multiple high-speed coaxial cables, and solves the problems of large space requirement and high cost of the connector for the equipment.

[0080] Please refer to FIG. 4, in some embodiments, the adapter circuit board 20 is bonded to the first circuit board 10 through the ACF conductive adhesive 50, or the adapter circuit board 20 is fixed to the first circuit board 10 through welding.

[0081] The ACF conductive adhesive is Anisotropic Conductive Film (ACF), which is a kind of connecting material with unique conductive properties. The ACF conductive adhesive 50 is a transparent polymer connecting material with three major properties of bonding, conductive and insulation. The working principle of the ACF conductive adhesive 50 is based on the arrangement and connection of conductive particles 51 under high temperature and high pressure. In the pressing process, the conductive particles 51 (usually metal particles) form a conductive channel in the insulating adhesive film. This structure makes the ACF conductive adhesive 50 have high conductivity in the vertical direction, and high insulation in the parallel direction.

[0082] As shown in FIG. 4, the ACF conductive adhesive 50 mainly includes a polymer substrate and conductive particles 51 dispersed therein, the conductive particles 51 are usually metal particles such as gold, silver, nickel, etc., and can also be tiny particles made of carbon or other conductive materials. The ACF conductive adhesive 50 is arranged between the adapter circuit board 20 and the first circuit board 10, the conductive particles 51 can provide an electrically conductive path between the first pad 111 and the second connecting structure 212 in relative alignment, and / or the first pad 111 and the second connecting structure 212 are in direct contact to realize electrical connection.

[0083] In the manufacturing of the circuit board structure 100, the ACF conductive adhesive 50 is first placed on the surface of the first circuit board 10 or the surface of the adapter circuit board 20, and then the adapter circuit board 20 is connected to the first circuit board 10 by compression. On one hand, the ACF conductive adhesive 50 can bond the adapter circuit board 20 and the first circuit board 10, and on the other hand, the second connection structure 212 on the adapter circuit board 20 can be electrically connected to the first pad 111 on the first circuit board 10 through the conductive particles 51 in the ACF conductive adhesive 50, or the second connection structure 212 and the first pad 111 are electrically connected by contact. Since the second connection structure 212 protrudes from the surface of the adapter circuit board 20, after the adapter circuit board 20 is connected to the first circuit board 10 by compression, the second connection structure 212 and the first pad 111 disposed opposite to it are connected through the conductive particles 51, while the second connection structure 212 and the first pad 111 disposed opposite to it, and the surface of the adapter circuit board 20 and the surface of the first circuit board 10, do not form a continuous layer of conductive particles 51, so the ACF conductive adhesive 50 can realize electrical conduction in the vertical direction of the first circuit board 10.

[0084] The first circuit board 10 is provided with a plurality of first pads 111, and the adapter circuit board 20 is provided with a plurality of second connection structures 212. In the case where the adapter circuit board 20 is connected to the first circuit board 10 by the ACF conductive adhesive 50, the plurality of first pads 111 are electrically connected to the corresponding second connection structures 212, and there is no need to separately solder each first pad 111 to the corresponding second connection structure 212. By adopting the above technical solution, the second connection structure 212 and the corresponding first pad 111 are electrically connected by the ACF conductive adhesive 50, and the manufacturing method of the circuit board structure 100 is simple and efficient.

[0085] In other embodiments, the adapter circuit board 20 is fixed to the first circuit board 10 by soldering, and the second connection structure 212 and the first pad 111 are electrically connected by soldering.

[0086] By adopting the above technical solution, the adapter circuit board 20 can be bonded to the first circuit board 10 by the ACF conductive adhesive 50 or soldered to the first circuit board 10, which can not only realize the mutual fixation of the adapter circuit board 20 and the first circuit board 10, but also realize the electrical connection between the connection structure 21 and the first pad 111. The fixing method of the adapter circuit board 20 is flexible and convenient to implement, and the manufacturing efficiency of the circuit board structure 100 is high.

[0087] Please refer to FIGS. 4-6. In some embodiments, the adapter circuit board 20 is provided with a plurality of through holes filled with conductive material, and the first connection structure 211 and the second connection structure 212 are respectively covered on opposite sides of the through hole 204 and are connected through the hole copper 23.

[0088] In some embodiments, the adapter circuit board 20 can be made of a double-sided copper-clad flexible copper clad laminate (FCCL) plate, the via hole penetrates through the double-sided copper-clad FCCL plate, and the via hole 204 is filled with a conductive material (such as copper, conductive ink, etc.); the first connection structure 211 and the second connection structure 212 respectively cover opposite sides of the via hole and are conductive through the conductive material in the via hole. In other embodiments, the adapter circuit board 20 can also be made of multiple FCCL plates.

[0089] The first connection structure 211 and the second connection structure 212 cover the via hole, wherein the cross-sectional area of the first connection structure 211 and the second connection structure 212 is greater than or equal to the cross-sectional area of the via hole, and in this embodiment, the cross-sectional area of the first connection structure 211 and the second connection structure 212 is greater than the cross-sectional area of the via hole, the orthographic projection of the first connection structure 211 towards the via hole completely covers the via hole, and the orthographic projection of the second connection structure 212 towards the via hole 204 also completely covers the via hole, to facilitate the connection of the first circuit board 10 and another circuit board.

[0090] By adopting the above technical solution, the first connection structure 211 and the second connection structure 212 respectively cover opposite sides of the via hole and are conductive through the conductive material in the via hole, without the need to set a circuit structure in the adapter circuit board 20 for conducting the first connection structure 211 and the second connection structure 212, the structure of the adapter circuit board 20 is simple, the manufacturing is simple and convenient, and the manufacturing efficiency is higher.

[0091] As shown in FIG. 6, in some embodiments, the conductive material in the via hole is a hole copper 23, the first connection structure 211 includes a first base copper part 2111 and a first electroplated copper part 2112 integrated with the hole copper 23, and the second connection structure 212 includes a second base copper part 2121 and a second electroplated copper part 2122 integrated with the hole copper 23.

[0092] Please refer to FIG. 6, FIG. 13A-FIG. 13D, in some embodiments, the adapter circuit board 20 is made of a double-sided copper FCCL board. As shown in FIG. 13A, the FCCL board includes a dielectric layer 201 and a base copper layer 202 arranged on both sides of the dielectric layer 201. In the process of making the adapter circuit board 20, a through hole 204 is first made on the adapter circuit board 20, which penetrates the dielectric layer 201 and the two layers of base copper layer 202; as shown in FIG. 13B, copper is plated on the adapter circuit board 20 to form a hole copper 23 and two layers of plated copper layer 203; then, as shown in FIG. 13C and FIG. 13D, the adapter circuit board 20 is subjected to a patterning process to form a first connection structure 211 and a second connection structure 212. The first connection structure 211 includes a first base copper part 2111 and a first electroplated copper part 2112, the first base copper part 2111 is formed by patterning the base copper layer 202, and the first electroplated copper part 2112 is formed by patterning the plated copper layer 203; the second connection structure 212 includes a second base copper part 2121 and a second electroplated copper part 2122 electroplated with the hole copper 23, the second base copper part 2121 is formed by patterning the second base copper layer 202, and the second electroplated copper part 2122 is formed by patterning the plated copper layer 203.

[0093] As can be seen, the first connection structure 211 and the second connection structure 212 are both copper pillars and both include a base copper part and an electroplated copper part. The first connection structure 211 and the second connection structure 212 are an integrated structure arranged on both sides of the through hole 204, and are symmetrically arranged and electrically connected through the hole copper 23, facilitating the connection of the first circuit board 10 and another circuit board.

[0094] As shown in FIG. 6, in some embodiments, the height H1 of the first connection structure 211 is 60-90 μm; and / or, the height H2 of the second connection structure 212 is 60-90 μm.

[0095] The height H1 of the first connection structure 211 refers to the height of the first connection structure 211 protruding from the surface of the adapter circuit board 20 in the thickness direction of the adapter circuit board 20. The height H2 of the second connection structure 212 refers to the height of the second connection structure 212 protruding from the surface of the adapter circuit board 20 in the thickness direction of the adapter circuit board 20.

[0096] The height of the first connection structure 211 can be 60-90 μm, for example, the height of the first connection structure 211 is 60 μm, 65 μm, 70 μm, 75 μm, 80 μm, 85 μm, 90 μm, etc. The height of the second connection structure 212 can be 60-90 μm, for example, the height of the second connection structure 212 is 60 μm, 65 μm, 70 μm, 75 μm, 80 μm, 85 μm, 90 μm, etc.

[0097] Please refer to FIG. 4 to FIG. 9, the surface of the first circuit board 10 is generally provided with a solder resist layer 16, the first pad 111 is exposed through the window in the solder resist layer 16, the thickness of the solder resist layer 16 is generally 20-30 μm, the initial thickness of the ACF conductive adhesive 50 is about 40 μm, and the thickness of the ACF conductive adhesive 50 after compression is about 30 μm, if the height of the second connecting structure 212 is lower than the total thickness of the solder resist layer 16 and the ACF conductive adhesive 50, there is a risk that the second connecting structure 212 cannot be connected to the first pad 111. Therefore, the height of the second connecting structure 212 is greater than or equal to the total thickness of the solder resist layer 16 and the ACF conductive adhesive 50.

[0098] The first connecting structure 211 is used to connect the second circuit board 30 or the third circuit board 40, the surface of the second circuit board 30 or the third circuit board 40 is provided with a solder resist layer, and the thickness of the solder resist layer is also generally 20-30 μm, in the embodiment of the application, the height of the first connecting structure 211 is greater than or equal to the total thickness of the solder resist layer and the ACF conductive adhesive 50.

[0099] By setting the height range of the first connecting structure 211 and the second connecting structure 212 to be greater than or equal to 60 μm, the second connecting structure 212 is stably connected to the first circuit board 10, and the first connecting structure 212 is stably connected to another circuit board (for example, the second circuit board 30 or the third circuit board 40), thereby reducing the risk of poor connection; at the same time, by setting the height range of the first connecting structure 211 and the second connecting structure 212 to be less than or equal to 90 μm, the height of the first connecting structure 211 and the second connecting structure 212 is not too large to occupy too much space, and the processing difficulty of the adapter circuit board 20 is also reduced, thereby improving the production efficiency.

[0100] Preferably, the height of the first connecting structure 211 and the second connecting structure 212 is 60 μm-80 μm, which can improve the connection stability between the adapter circuit board 20 and another circuit board, and also can reduce the height space occupied by the adapter circuit board 20.

[0101] Please refer to FIG. 6 and FIG. 10, in some embodiments, the first connecting structure 211 is in a cylindrical or square column shape, a plurality of first connecting structures 211 are arranged in a matrix shape, the length of the first connecting structure 211 in the direction parallel to the adapter circuit board 20 is 300 μm-450 μm, the spacing between the first connecting structures 211 is 800 μm-1000 μm, and / or the second connecting structure 212 is in a cylindrical or square column shape, a plurality of second connecting structures 212 are arranged in a matrix shape, the length of the second connecting structure 212 in the direction parallel to the adapter circuit board 20 is 300 μm-450 μm, and the spacing between the second connecting structures 212 is 800 μm-1000 μm.

[0102] The first connecting structure 211 and the second connecting structure 212 are made by etching a copper layer, and the first connecting structure 211 and the second connecting structure 212 can be cylindrical or square columnar. The signal lines 131 on the first circuit board 10 are arranged side by side, and the first pads 111 corresponding to the signal lines 131 are sequentially arranged. In this way, the plurality of first connecting structures 211 are arranged in a matrix, which can facilitate the electrical connection between the adapter circuit board 20 and the first circuit board 10, so that the plurality of first connecting structures 211 are connected to the first pads 111 one by one.

[0103] The length of the first connecting structure 211 is 300 μm to 450 μm. For the cylindrical first connecting structure 211, the diameter of the first connecting structure 211 is 300 μm to 450 μm. For the square columnar first connecting structure 211, the side length of the first connecting structure 211 is 300 μm to 450 μm.

[0104] Similarly, the length of the second connecting structure 212 is 300 μm to 450 μm. For the cylindrical second connecting structure 212, the diameter of the second connecting structure 212 is 300 μm to 450 μm. For the square columnar second connecting structure 212, the side length of the second connecting structure 212 is 300 μm to 450 μm.

[0105] In the embodiment, the size of the first connecting structure 211 and the second connecting structure 212 meets the above range, which can facilitate the electrical connection between the first connecting structure 211 and the second connecting structure 212 and the pad.

[0106] In addition, the distance between the first connecting structures 211 and the distance between the second connecting structures 212 meet the above range, which can reduce the risk of poor connection.

[0107] The circuit board structure 100 provided by the embodiment can be applied to a signal transmission assembly, and the signal transmission assembly further includes a second circuit board 30 connected to the circuit board structure 100.

[0108] Please refer to FIG. 4. In some embodiments, the adapter circuit board 20 is fixedly connected to the second circuit board 30 through the ACF conductive adhesive 50. The second circuit board 30 is provided with a plurality of second pads 31, and the first connecting structure 211 is connected to the second pad 31 and electrically connected.

[0109] The first connecting structure 211 is arranged opposite to the second pad 31. Optionally, the orthographic projection of the first connecting structure 211 towards the second circuit board 30 falls within the contour range of the second pad 31, that is, the cross-sectional area of the first connecting structure 211 is less than or equal to the cross-sectional area of the second pad 31. The conductive particles 51 in the ACF conductive adhesive 50 can provide a conduction path between the first connecting structure 211 and the second pad 31, or the first connecting structure 211 directly contacts the second pad 31 to realize conduction.

[0110] In the process of manufacturing the signal transmission assembly, the first connecting structure 211 and the second pad 31 do not need to be connected one by one by welding. Only the adapter circuit board 20 and the second circuit board 30 are bonded by the ACF conductive adhesive 50, which not only realizes the relative fixation of the adapter circuit board 20 and the second circuit board 30, but also realizes the one-to-one correspondence conduction between the plurality of first connecting structures 211 and the plurality of second pads 31.

[0111] In this way, the two sides of the adapter circuit board 20 are bonded with the first circuit board 10 and the second circuit board 30 by the ACF conductive adhesive 50, and the manufacturing efficiency is higher. The adapter circuit board 20 does not need to be fixed on the PCB module by screws or other fasteners, and the signal transmission assembly in which the circuit board structure 100 is located can be made smaller and thinner.

[0112] In other embodiments, the adapter circuit board 20 can also be connected to the second circuit board 30 by welding.

[0113] Please refer to FIG. 2 and FIG. 4. In some embodiments, the signal transmission assembly further comprises a third circuit board 40, and the adapter circuit board 20 is provided with at least two, one of which is electrically connected to one end of the signal line 131 and the second circuit board 30, and the other is electrically connected to the other end of the signal line 131 and the third circuit board 40.

[0114] The third circuit board 40 can be a circuit board module or a single circuit board. Optionally, the third circuit board 40 is a circuit board module in an electronic device.

[0115] One of the second circuit board 30 and the third circuit board 40 is electrically connected to the head end of the signal line 131 through the adapter circuit board 20, and the other is electrically connected to the tail end of the signal line 131 through the adapter circuit board 20, so that the signal line 131 on the first circuit board 10 can transmit signals between the second circuit board 30 and the third circuit board 40. In the circuit board structure 100 provided in the above embodiment, the first circuit board 10 and the adapter circuit boards 20 at both ends thereof replace the high-speed coaxial cable and the coaxial connectors at both ends thereof, not only reducing the space occupation, but also reducing the signal loss between the coaxial connector and the circuit board.

[0116] Referring to FIG. 4, some embodiments of the present application provide a circuit board structure 100, comprising a first circuit board 10 and a conversion circuit board 20, the first circuit board 10 comprising a plurality of signal lines 131, the conversion circuit board 20 having a first surface 20a and a second surface 20b oppositely arranged, a plurality of first connecting structures 211 being protruded on the first surface 20a, a plurality of second connecting structures 212 being protruded on the second surface 20b, the first connecting structures 211 and the second connecting structures 212 corresponding and conducting; the second surface 20b being connected to the first circuit board 10, the second connecting structures 212 being opposite to and electrically connected with the first pads 111 on the first circuit board 10, the first surface 20a being used for connecting a second circuit board 30, the first connecting structures 211 being used for being opposite to and electrically connected with second pads 31 on the second circuit board 30. In this way, the first circuit board 10 and the conversion circuit board 20 replace the traditional coaxial cable and coaxial connector, reduce the occupied space, and reduce the connection loss.

[0117] Referring to FIGS. 4 to 11, the embodiments of the second aspect of the present application provide a manufacturing method of a circuit board structure 100, for manufacturing the circuit board structure 100 provided in the first aspect. The manufacturing method of the circuit board structure 100 comprises:

[0118] Step S1: providing a first circuit board 10, the first circuit board 10 comprising a plurality of signal lines 131.

[0119] The first circuit board 10 is a high-speed multilayer circuit board, preferably a flexible circuit board, and the base material of the first circuit board 10 can be selected from high-frequency materials.

[0120] In some embodiments, the manufacturing method of the first circuit board 10 comprises one or more of the following steps: cutting, drilling, inner layer circuit manufacturing, lamination, drilling, black shadow copper plating, outer layer circuit manufacturing, pasting and pressing a cover film 15, manufacturing a solder mask layer 16, nickel gold plating, testing, and profile punching.

[0121] In some embodiments, the signal lines 131 are arranged in the inner metal layer 13 of the first circuit board 10, the first circuit board 10 comprising a first outer metal layer 11, a second outer metal layer 12, and at least one inner metal layer 13 arranged between the first outer metal layer 11 and the second outer metal layer 12, the signal lines 131 being arranged in the inner metal layer 13.

[0122] Step S2: manufacturing a plurality of connecting structures 21, the connecting structures 21 being protruded on the surface of the first circuit board 10 and electrically connected to a corresponding signal line 131.

[0123] The connecting structures 21 are also used for electrically connecting with the second circuit board 30, so as to electrically connect the plurality of signal lines 131 with the second circuit board 30.

[0124] In some embodiments, the connection structure 21 is directly formed on the first circuit board 10; in other embodiments, the connection structure 21 is formed on the adapter circuit board 20, and the adapter circuit board 20 is fixed to the first circuit board 10 so that the connection structure 21 protrudes from the surface of the first circuit board 10.

[0125] The circuit board structure 100 manufactured by the manufacturing method described above comprises the first circuit board 10 and the connection structure 21 protruding from the first circuit board 10, and the first circuit board 10 is provided with a plurality of signal lines 131, so that the first circuit board 10 can replace a plurality of high-speed coaxial cables, and the first circuit board 10 can be connected to the second circuit board 30 through the plurality of connection structures 21 protruding from the surface thereof, i.e., the first circuit board 10 does not need to be connected to the second circuit board 30 through coaxial connectors. The circuit board structure 100 manufactured by the manufacturing method described above replaces the high-speed coaxial cables, and the circuit board structure 100 also omits the coaxial connectors, so that the circuit board structure 100 has a simple structure and a small size, reduces the occupied space, and the manufacturing method described above has high manufacturing efficiency and low cost.

[0126] Please refer to FIGS. 4-12, and the plurality of connection structures 21 are manufactured in step S2, comprising:

[0127] In step S21, the adapter circuit board 20 is manufactured, the adapter circuit board 20 comprises a first surface 20a and a second surface 20b arranged oppositely, the plurality of connection structures 21 comprises a plurality of first connection structures 211 protruding from the first surface 20a and a plurality of second connection structures 212 protruding from the second surface 20b, and the first connection structures 211 and the second connection structures 212 are in one-to-one correspondence and conductive.

[0128] The adapter circuit board 20 can be a flexible circuit board or a rigid circuit board. The first connection structures 211 and the second connection structures 212 are conductive structures, such as copper pillars, pads, etc. In some embodiments, the first connection structures 211 and the second connection structures 212 are copper pillars and are conductive through the metallized through holes 204; the first connection structures 211 and the second connection structures 212 are arranged on the two sides of the through holes 204 and face each other.

[0129] In step S22, the adapter circuit board 20 is fixedly connected to the first circuit board 10, so that the second connection structures 212 are electrically connected to the signal lines 131.

[0130] The adapter circuit board 20 can be connected to the first circuit board 10 through the ACF conductive adhesive 50, and it can be understood that the adapter circuit board 20 can also be connected to the first circuit board 10 through welding or the like.

[0131] After the adapter circuit board 20 is fixedly connected between the first circuit board 10 and the second circuit board 30, the second connecting structure 212 is electrically connected to the signal line 131 towards the first circuit board 10. In some embodiments, the first circuit board 10 is provided with a plurality of first pads 111, each of which is connected to a signal line 131, and the second connecting structure 212 on the adapter circuit board 20 is connected to the first pad 111.

[0132] The first connecting structure 211 on the adapter circuit board 20 is used to connect another circuit board, and in some embodiments, the first connecting structure 211 is used to connect the second circuit board 30, which is provided with a plurality of second pads 31, and the first connecting structure 211 is connected to the second pad 31, so that the signal line 131, the first pad 111, the second connecting structure 212, the first connecting structure 211 and the second pad 31 are electrically connected in sequence.

[0133] The circuit board structure 100 manufactured by the above manufacturing method includes the first circuit board 10 and the adapter circuit board 20, the second connecting structure 212 protruding from one side of the adapter circuit board 20 is electrically connected to the first circuit board 10, and the first connecting structure protruding from the other side of the adapter circuit board 20 is used to be electrically connected to the second circuit board 30, so that the adapter circuit board 20 can electrically connect the first circuit board 10 and the second circuit board 30, replacing the coaxial connector used in combination with the high-speed coaxial cable; the circuit board structure 100 manufactured by the above manufacturing method has a simple structure and a small size, reduces the occupied space, and the above manufacturing method first manufactures the adapter circuit board 20 and then fixes the adapter circuit board 20 on the first circuit board 10, so that the adapter circuit board 20 can be manufactured separately, the manufacturing method is flexible, the yield is high, and the structure of the first circuit board 10 does not need to be changed, so that the overall manufacturing efficiency of the circuit board structure 100 is high and the cost is low.

[0134] Please refer to FIGS. 13A-13D, step S21 manufacturing the adapter circuit board 20, including the following steps.

[0135] As shown in FIG. 13A, a substrate is provided, which includes a dielectric layer 201 and a base copper layer 202 provided on both sides of the dielectric layer 201, then a plurality of through holes 204 are drilled on the substrate, and the through holes 204 are through holes penetrating the dielectric layer 201 and the base copper layer 202 on both sides of the dielectric layer 201.

[0136] As shown in FIG. 13B, copper is plated on the substrate to fill the hole copper 23 in the through hole 204 and form a plated copper layer 203 on the surface of the substrate.

[0137] As shown in FIGS. 13C-13D, the substrate is etched to form a plurality of protruding first connecting structures 211 and second connecting structures 212 on opposite sides of the dielectric layer 201, respectively, and the first connecting structures 211 and the second connecting structures 212 are electrically connected through the hole copper 23.

[0138] In some embodiments, the method of etching the substrate by photolithography includes the following steps: as shown in FIG. 13C, the dry film 205 is attached to the surface of the substrate; as shown in FIGS. 6 and 13D, the copper layer on the surface of the substrate layer is patterned by exposure, development, etching, and film stripping to form the first connecting structures 211 and the second connecting structures 212.

[0139] In some embodiments, the specific process of making the adapter circuit board 20 is as follows: cutting, drilling, black shadowing (or copper plating), copper plating, film attaching, exposure and development, etching, nickel gold plating, and punching.

[0140] In some embodiments, the substrate selected for the adapter circuit board 20 can be a double-sided copper-clad substrate, the thickness of the base copper layer 202 is 35 μm, and the thickness of the dielectric layer 201 is 25 μm-50 μm. After the double-sided substrate is cut into single sheets, the hole drilling, black shadowing or copper plating, copper plating process is performed to fill the holes with copper and thicken the copper layer on the surface of the substrate to 60 μm-90 μm, i.e., the thickness of the base copper layer 202 and the plated copper layer 203 is 60 μm-90 μm. Then, the film is attached, exposed, developed, etched, and stripped to form copper pillars (i.e., the first connecting structures 211 and the second connecting structures 212) with a height of 60 μm-90 μm on both sides, and the first connecting structures 211 and the second connecting structures 212 are in communication through the hole copper 23. The copper pillars can be designed in cylindrical or square column shapes according to the design, and the copper pillars are arranged in a matrix. The punched single adapter circuit board 20 is assembled into a roll of material.

[0141] The adapter circuit board 20 made by the above method has a plurality of first connecting structures 211 and second connecting structures 212 protruding on both sides, respectively, and the first connecting structures 211 and the second connecting structures 212 are in one-to-one electrical communication to facilitate the connection of the first circuit board 10 and the second circuit board 30. The above adapter circuit board 20 has high connection reliability, and compared with the coaxial connector, the above adapter circuit board 20 has a thinner thickness, reduces the occupied space, and reduces signal loss.

[0142] Referring to FIGS. 14 and 15, in some embodiments, the step S22 of fixing and connecting the adapter circuit board 20 to the first circuit board 10 includes: bonding the adapter circuit board 20 to the first circuit board 10 by ACF conductive adhesive 50, wherein the second side 20b faces the first circuit board 10; and pressing the adapter circuit board 20, the ACF conductive adhesive 50, and the first circuit board 10.

[0143] Exemplarily, the ACF conductive adhesive 50 of the roll material is punched into a single piece of conductive adhesive with the same size as the adapter circuit board 20, and is assembled into a roll material strip; the ACF conductive adhesive 50 is attached to the first pads 111 of the first circuit board 10 which has been processed by means of an automatic attaching machine, and the surface release film is removed after pre-pressing; the adapter circuit board 20 in the form of a roll material strip is attached to the ACF conductive adhesive 50 by means of an automatic attaching machine, and the false pressing is performed by means of a vacuum rapid pressing device, the false pressing temperature is 80-100℃, the pressure is 5-10kg, the vacuum time is 1-3 seconds, and the pressing time is 3-5 seconds, and the false pressing stack structure comprises a 50μm release film, the product to be pressed, and a 50μm release film, so as to obtain the circuit board structure 100 shown in FIG. 5.

[0144] In some embodiments, after the circuit board structure 100 is made, the adapter circuit board 20 and the first circuit board 10 are bonded to the second circuit board 30 by means of the ACF conductive adhesive 50, wherein the ACF conductive adhesive 50 is arranged between the first surface 20a of the adapter circuit board 20 and the second circuit board 30.

[0145] Specifically, referring to FIG. 16, a layer of ACF conductive adhesive 50 is attached to the adapter circuit board 20, the size of the ACF conductive adhesive 50 is consistent with the size of the adapter circuit board 20, and the release film is removed after false pressing; referring to FIG. 17, the adapter circuit board 20 and the first circuit board 10 which have been false pressed and bonded are assembled to the second circuit board 30 by means of a jig positioning, and the false pressing is performed by means of a vacuum rapid pressing device, the false pressing temperature is 80-100℃, the pressure is 5-10kg, the vacuum time is 1-3 seconds, and the pressing time is 3-5 seconds, and the false pressing stack structure comprises a 50μm release film, the product to be pressed, and a 50μm release film; then, the second circuit board 30, the adapter circuit board 20, and the first circuit board 10 are bonded by means of two layers of ACF conductive adhesive 50 under the action of high temperature and high pressure by means of a vacuum rapid pressing device, the vacuum rapid pressing temperature is 160-180℃, the vacuum time is 10-20 seconds, and the pressing time is 100-150 seconds, and the pressing stack structure is a 70-130μm TPX film, the product to be pressed, and a 50μm 70-130μm TPX film. After the vacuum rapid pressing, the second circuit board 30 and the first circuit board 10 are connected by means of the adapter circuit board 20, so as to achieve the effect of high-speed signal transmission between different circuit boards. The pressed product is subjected to signal loss testing, and after the testing is qualified, batch production can be performed.

[0146] By means of the above technical solution, the first circuit board 10 and the adapter circuit board 20, and the adapter circuit board 20 and the second circuit board 30 are connected by means of the ACF conductive adhesive 50 respectively, and the manufacturing efficiency is relatively high.

[0147] In other embodiments, the ACF conductive adhesive 50 can be cancelled, and the adapter circuit board 20 is connected to the first circuit board 10 and the second circuit board 30 by welding.

[0148] Please refer to FIG. 2, the embodiment of the third aspect of the present application provides a signal transmission assembly, including the circuit board structure 100 provided by the first aspect or the second aspect, the second circuit board 30 and the third circuit board 40, the circuit board structure 100 includes the first circuit board 10 and the plurality of connection structures 21 arranged at the opposite ends of the first circuit board 10, and the first circuit board 10 includes a plurality of signal lines 131; the second circuit board 30 is connected to the head end of the signal line 131 through the connection structure 21 at one end of the first circuit board 10, and the third circuit board 40 is connected to the tail end of the signal line 131 through the connection structure 21 at the other end of the first circuit board 10.

[0149] The two ends of the signal line 131 are connected to the second circuit board 30 and the third circuit board 40 through the connection structure 21 respectively, so that the signal line 131 can transmit signals between the second circuit board 30 and the third circuit board 40, and thus the signal transmission assembly can replace the high-speed coaxial cable and the coaxial connector through the first circuit board 10 and the connection structure 21, thereby saving space.

[0150] In some embodiments, the circuit board structure 100 further includes an adapter circuit board 20, the adapter circuit board 20 includes a first surface 20a and a second surface 20b arranged oppositely, the plurality of connection structures 21 includes a plurality of first connection structures 211 protruding from the first surface 20a and a plurality of second connection structures 212 protruding from the second surface 20b, the first connection structure 211 and the second connection structure 212 are in one-to-one correspondence and conductive, the second connection structure 212 is connected to the first circuit board 10, and the first connection structure 211 is connected to the second circuit board 30.

[0151] Please refer to FIGS. 2 to 17, the embodiment of the fourth aspect of the present application provides a data center, including the circuit board structure 100 provided by the first aspect, the circuit board structure 100 manufactured by the manufacturing method provided by the second aspect or the signal transmission assembly provided by the third aspect.

[0152] The data center includes a plurality of devices, such as servers, switches, routers, etc.; the second circuit board 30 and the third circuit board 40 are circuit boards or circuit board modules in different devices, and the first circuit board 10 transmits signals between different circuit boards or circuit board modules through the signal line 131.

[0153] The data center provided by the embodiment of the present application includes the circuit board structure 100, which can replace the high-speed coaxial cable and the coaxial connector, thereby saving the installation space.

[0154] The above-described embodiments are only used to illustrate the technical solutions of the present application, but not limit them; although the present application is described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application.

Claims

1. A circuit board structure, wherein, The circuit board structure comprises: a first circuit board comprising a plurality of signal lines; a plurality of connecting structures protruding from a surface of the first circuit board, the connecting structures being electrically connected to a corresponding one of the signal lines; the connecting structures being further configured to electrically connect the first circuit board to a second circuit board so as to electrically connect the plurality of signal lines to the second circuit board.

2. The circuit board structure of claim 1, wherein, The first circuit board comprises a first outer metal layer, a second outer metal layer, and at least one inner metal layer disposed between the first outer metal layer and the second outer metal layer, the signal lines being lines in the inner metal layer; The first outer metal layer comprises a plurality of first pads corresponding to the signal lines, the connecting structures being connected to and electrically connected to the first pads, the connecting structures being protruding relative to the first pads.

3. The circuit board structure of claim 2, wherein, The circuit board structure further comprises an adapter circuit board comprising a first surface and a second surface disposed opposite to each other, the plurality of connecting structures comprising a plurality of first connecting structures protruding from the first surface and a plurality of second connecting structures protruding from the second surface, the first connecting structures and the second connecting structures being electrically connected to each other one by one; The second connecting structures are connected to and electrically connected to the first pads, the first connecting structures being configured to electrically connect the first circuit board to the second circuit board.

4. The circuit board structure of claim 3, wherein, The adapter circuit board is adhered to the first circuit board by ACF conductive adhesive, or the adapter circuit board is fixed to the first circuit board by soldering.

5. The circuit board structure of claim 3, wherein, The adapter circuit board comprises a plurality of through holes filled with conductive material, the first connecting structures and the second connecting structures being respectively disposed on opposite sides of the through holes and being electrically connected to each other through the through holes.

6. The circuit board structure of claim 5, wherein, The conductive material in the through holes is hole copper, the first connecting structures comprise a first base copper part and a first electroplated copper part integrated with the hole copper, and the second connecting structures comprise a second base copper part and a second electroplated copper part integrated with the hole copper.

7. The circuit board structure of any one of claims 3-6, wherein, The height of the first connecting structures is 60 μm to 90 μm; and / or The height of the second connecting structures is 60 μm to 90 μm.

8. The circuit board structure of any one of claims 3-6, wherein, The first connecting structures are columnar, the plurality of first connecting structures are arranged in a matrix, the length of the first connecting structures in a direction parallel to the adapter circuit board is 300 μm to 450 μm, the distance between the first connecting structures is 800 μm to 1000 μm, and / or The second connecting structures are columnar, the plurality of second connecting structures are arranged in a matrix, the length of the second connecting structures in a direction parallel to the adapter circuit board is 300 μm to 450 μm, the distance between the second connecting structures is 800 μm to 1000 μm.

9. A method of manufacturing a circuit board structure, wherein, comprises: providing a first circuit board comprising a plurality of signal lines; protruding from a surface of the first circuit board and electrically connected to a corresponding one of the signal lines, wherein the connecting structures are further configured to electrically connect the first circuit board to a second circuit board so as to electrically connect the plurality of signal lines to the second circuit board.

10. The method of manufacturing a circuit board structure according to claim 9, wherein, The method of manufacturing the plurality of connecting structures comprises: An adapter circuit board is fabricated, wherein the adapter circuit board includes a first side and a second side disposed opposite to each other, and the plurality of connection structures include a plurality of first connection structures protruding from the first side and a plurality of second connection structures protruding from the second side, wherein the first connection structure and the second connection structure correspond one-to-one and are electrically connected. The adapter circuit board is fixedly connected to the first circuit board, so that the second connection structure is electrically connected to the signal line.

11. The method of manufacturing a circuit board structure according to claim 10, wherein, The fabrication of the adapter circuit board includes: A substrate is provided, the substrate comprising a dielectric layer and base copper layers disposed on both sides of the dielectric layer; Multiple through holes are drilled in the substrate; Copper is plated on the substrate to fill the vias with copper and form a copper plating layer on the surface of the substrate; The substrate is etched to form a plurality of protruding first connection structures and second connection structures on opposite sides of the dielectric layer, wherein the first connection structures and second connection structures are electrically connected through the through-hole copper.

12. The method of manufacturing a circuit board structure according to claim 10 or 11, wherein, The adapter circuit board is fixedly connected to the first circuit board, including: The adapter circuit board is bonded to the first circuit board using ACF conductive adhesive, wherein the second side faces the first circuit board; The adapter circuit board, the ACF conductive adhesive, and the first circuit board are pressed together.

13. A signal transmission assembly, comprising: include: A circuit board structure, wherein the circuit board structure is the circuit board structure of any one of claims 1-8 or the circuit board structure of any one of claims 9-12 manufactured by the manufacturing method, the circuit board structure includes a first circuit board and a plurality of the connection structures disposed at opposite ends of the first circuit board, the first circuit board including a plurality of signal lines; The second circuit board is connected to the beginning of the signal line through the connection structure at one end of the first circuit board; The third circuit board is connected to the tail end of the signal line via the connection structure at the other end of the first circuit board.

14. A data center, wherein, Includes the circuit board structure as described in any one of claims 1-8, the circuit board structure manufactured by the method of manufacturing the circuit board structure as described in any one of claims 9-12, or the signal transmission component as described in claim 13.

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