Flexible metal layer composite flexible PCB (Printed Circuit Board) type connecting piece

Abstract

The utility model discloses a flexible metal layer composite flexible PCB plate-type connecting piece, and the connecting piece comprises a flexible metal layer connecting piece which comprises metal belts which are used for transmitting a large current and are isolated from each other; and a flexible PCB connecting piece, wherein the flexible PCB connecting piece is used for transmitting a high-density integrated signal; the flexible metal layer connecting piece and the flexible PCB connecting piece are partially or completely overlapped so that at least one connecting end can be connected to the same component. The flexible PCB connecting piece and the flexible metal layer connecting piece are used in an overlapped mode, the advantages of highly integrated signal transmission of the flexible PCB connecting piece and large-current transmission of the flexible metal layer connecting piece can be played at the same time, and the three-dimensional connector can have very small thickness and is suitable for achieving three-dimensional connection of electronic components at different positions in narrow and limited spaces.

Description

Technical Field

[0001] This application belongs to the technical field of electronic connectors, and particularly relates to a flexible metal layer composite flexible PCB board connector. Background Art

[0002] A flexible printed circuit board (abbreviated as FPC) is a highly reliable and excellent flexible printed circuit board made of polyimide or polyester film as the substrate. A flexible printed circuit board usually includes an insulating film, a conductor, and an adhesive. The conductor usually uses copper foil, which is basically divided into electrolytic copper and rolled copper. The common thicknesses are 1 ounce, 1 / 2 ounce, and 1 / 3 ounce, and there are also a few of 2 ounces.

[0003] According to the manufacturing process and structural characteristics of the existing flexible printed circuit board, the thickness specifications of the copper foil used are usually 35μm, 50μm, and 70μm. In the actual application process, the maximum allowable current load of the channels formed by a single piece of copper foil is only a few amperes.

[0004] In actual use, especially in the narrow and limited spaces in the fields of aerospace, military, etc., there will be three-dimensional interconnection between highly integrated electronic components, and at the same time, high-density signals and large currents of dozens or even hundreds of amperes are transmitted. At this time, the flexible PCB connector cannot meet this use requirement. Summary of the Invention

[0005] In view of the problems of the existing technology, this application proposes the following technical solutions:

[0006] A flexible metal layer composite flexible PCB board connector, comprising:

[0007] A flexible metal layer connector, the flexible metal layer connector includes metal strips that transmit large currents and are isolated from each other;

[0008] And a flexible PCB connector that transmits high-density integrated signals;

[0009] The flexible metal layer connector and the flexible PCB connector are partially or completely overlapped so that at least one connection end is connected to the same component.

[0010] As a preference of the above technical solution, the metal strips are separated by a hollow isolation part formed on a metal conductive sheet layer, and the metal conductive sheet layer is deformed by an external force and maintains the deformed state after the external force is withdrawn.

[0011] As a preference of the above technical solution, it further includes a coating layer, the coating layer is coated outside the metal conductive sheet layer, and the coating layer is embedded in the isolation part to physically insulate and isolate adjacent metal strips.

[0012] Preferably, as the above technical solution, the metal belt is provided with connection holes and / or avoidance holes.

[0013] Preferably, as the above technical solution, the metal conductive sheet layer is a sheet made of any one or a combination of two or more of copper, gold, silver, molybdenum silicide, and chromium.

[0014] Preferably, as the above technical solution, the thickness of the metal conductive sheet layer does not exceed 0.2 mm, and the minimum width of the isolation part is not less than 0.3 mm.

[0015] Preferably, as the above technical solution, the coating layer is a composition of any one or a combination of two or more of polyethylene terephthalate, polycarbonate, polyimide, polyethylene propylene ester, and polypropylene.

[0016] Preferably, as the above technical solution, the outside of the metal conductive sheet layer coated in the coating layer is single-piece or multi-piece laminated.

[0017] The beneficial effects of this application are as follows: The flexible PCB connector and the flexible metal layer connector are used in combination in this application. By utilizing the characteristic that more copper foils can be integrated in the flexible PCB, the highly integrated transmission of control signals is realized. The flexible metal layer connector can give full play to its current-carrying advantage, and thus can simultaneously meet the requirements of high-density integrated signal transmission and large-current transmission. Moreover, the flexible metal layer composite flexible PCB plate connector and the flexible PCB can be used in combination to have a very small thickness, which is suitable for realizing three-dimensional connection of electronic components at different positions in narrow and restricted spaces. Description of the Drawings

[0018] Figure 1 It shows a schematic structural diagram of a flexible metal layer composite flexible PCB plate connector;

[0019] Figure 2 It shows Figure 1 The partial enlarged view at A in

[0020] Figure 3 It shows a schematic structural diagram of one layer state of a flexible metal layer composite flexible PCB plate connector;

[0021] Figure 4 It shows a schematic diagram of the state where a flexible metal layer composite flexible PCB plate connector is used to connect four connectors at different positions;

[0022] Figure 5 It shows a schematic structural diagram of two layer states of a flexible metal layer composite flexible PCB plate connector;

[0023] Figure 6 It shows a schematic structural diagram of the metal conductive sheet layer after material removal processing;

[0024] Figure 7 Shown is Figure 6 a partial enlarged view at position B in;

[0025] Figure 8 Shown is a schematic diagram of the front view state of the flexible metal layer connector and the flexible PCB connector used in cooperation;

[0026] Figure 9 Shown is an exploded state schematic diagram of the flexible metal layer connector and the flexible PCB connector used in cooperation;

[0027] Figure 10 Shown is an exploded state schematic diagram of the flexible metal layer connector and the flexible PCB connector used in cooperation in another embodiment. Detailed implementation manners

[0028] To make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions of the present application will be clearly and completely described below in conjunction with the embodiments.

[0029] Figure 1 Shown is a structural schematic diagram of the flexible metal layer composite flexible PCB plate connector recorded in this embodiment. According to Figure 1 as shown, the flexible metal layer composite flexible PCB plate connector of the present application includes a sheet-like metal conductive sheet layer 10. A plurality of isolation parts 11 are formed on the metal conductive sheet layer 10 by a material removal process. The isolation parts 11 divide the originally sheet-like metal conductive sheet layer 10 into a plurality of mutually isolated metal strips 12 on the metal conductive sheet layer 10. The metal strips 12 are used as current-carrying channels to be connected between two connectors, rigid PCBs or other components; Figure 3 Shown is a layered structural schematic diagram of the flexible metal layer composite flexible PCB plate connector. A coating layer 20 is formed outside the metal conductive sheet layer 10. The coating layer 20 completely wraps the metal conductive sheet layer 10 inside, and at the same time fills the isolation parts 11 to isolate adjacent metal strips 12.

[0030] Refer to Figure 1 and 2 , connection holes 121 are formed at both ends of each metal strip 12, respectively for realizing electrical connection with other components, such as connectors, active devices, printed circuit boards, etc.; at the same time, according to different design requirements, avoidance holes 122 are formed on the specific metal strips 12. The avoidance holes 122 are suitable for avoiding other components during the connection process; usually the size of the connection holes 121 is smaller than that of the avoidance holes 122.

[0031] Figure 4The figure shows a schematic diagram of the state where the flexible metal layer composite flexible PCB board connector is used to connect the connectors 31, 32, 33, and 34 at four different positions. The flexible metal layer composite flexible PCB board connector is a one-to-three type connector, which is used to transmit the signals on the connector 31 to the connectors 32, 33, and 34 respectively, and then realize the docking with other corresponding connectors. At the same time, combined with Figure 4 , it can be seen that the connectors 32, 33, and 34 are located at different positions in the three-dimensional space respectively, and the flexible metal layer composite flexible PCB board connector can be bent well to meet these connection requirements.

[0032] Traditional flexible circuit boards are applied to stack a large number of precision components in narrow and limited spaces, playing the role of signal transmission and current transmission. They can be applied to most working conditions. In particular, the flexible circuits inside can meet the connection requirements of electronic components in special-shaped spaces (or three-dimensional spaces). Therefore, flexible circuit boards are used in the field of electronic control to connect electronic components or connectors in three-dimensional spaces to achieve signal and current transmission. This is a mature and stable technical trend that has been formed.

[0033] In order to meet the current transmission requirements, current transmission can be achieved by using nearly twenty or more layers of flexible circuit boards in parallel. Although the thickness of a single flexible circuit board itself is about 0.1 mm and it has good bending performance, when nearly twenty or more layers of flexible circuit boards are fixed in parallel to achieve current transmission, due to the stress characteristics of the base material of the flexible circuit board, it is difficult to bend when connecting electronic components in special-shaped spaces, and the stacked flexible circuit boards have a large thickness. After bending, the copper foils on the inner and outer sides will be stretched to different degrees, posing a risk of damaging the flexible circuit board. That is to say, the currently used flexible circuit boards cannot meet the current-carrying requirements while ensuring good bending performance.

[0034] At the initial stage of the technology research and development by the applicant of this application, the above-mentioned flexible circuit board was also used and expected to solve the technical problem of current transmission of hundreds of amperes. However, it has always been impossible to ensure good bending performance while achieving the technical purpose of current transmission, which has led to the inability of the flexible circuit board to be bent to the extent that it can connect two connectors in narrow and limited spaces.

[0035] In this embodiment, the applicant of this application completely abandons the existing mature technical route of flexible circuit boards and designs the structure of the flexible metal layer composite flexible PCB board connector described in this application. The metal conductive sheet layer 10 in the flexible metal layer composite flexible PCB board connector is an excellent conductor material of electricity, which can realize the functions of signal transmission and current transmission, and at the same time, the metal conductive sheet layer 10 can carry current transmission of hundreds of amperes.

[0036] Table 1 shows the relationship table of copper foil thickness, line width and current in PCB design. This relationship table is publicly available on the Internet (URL: https: / / www.elecfans.com / d / 659395.html) and is only excerpted for illustration purposes.

[0037]

[0038] Table 1: Relationship Table of Copper Foil Thickness, Line Width and Current in PCB Design

[0039] Taking a flexible circuit board as an example, for a flexible circuit board with 2 ounces (copper foil thickness 70μm) and a line width of 2.5mm, after 20 identical flexible circuit boards are connected in parallel, the maximum load current can reach 120A, which can basically meet the requirements for current transmission of hundreds of amperes; however, correspondingly, the common thickness of flexible PCBs is 0.2mm, and the total thickness reaches 4mm after 20 identical flexible circuit boards are connected in parallel.

[0040] According to the description of this embodiment, the metal conductive sheet layer 10 designed in this application has the same width. When the maximum current-carrying capacity reaches 120A, the thickness does not exceed 1.4mm. With the outer coating layer 20 formed, the total thickness will not exceed 2mm. The advantages here are not only reflected in the ability to carry large currents, but also that the material of the entire flexible metal layer composite flexible PCB plate connector is mainly the metal conductive sheet layer 10. Taking copper as an example for the metal conductive sheet layer 10, it has excellent bending performance and can meet the requirements for large-current transmission and bending between different electrical components in three-dimensional space.

[0041] In this embodiment, regarding the material of the metal conductive sheet layer 10, the metal conductive sheet layer 10 is a sheet made of any one or two or more combinations, and copper is preferred, with a copper purity of more than 99.7%.

[0042] In this embodiment, regarding the material of the metal conductive sheet layer 10, the thickness of the metal conductive sheet layer 10 does not exceed 0.2mm, which is related to the width design of the isolation part 11 inside the metal conductive sheet layer 10 and the subsequent forming process.

[0043] In this embodiment, regarding the material of the metal conductive sheet layer 10, the design of the isolation part 11 is used to form several mutually isolated metal strips 12 on the metal conductive sheet layer 10. On the premise of meeting the design requirements for current-carrying design, the cross-sectional size of the metal strip 12 cannot be changed. When applied to narrow and limited spaces, it is necessary to compress the width of the isolation part 11 as much as possible to achieve the miniaturization of this flexible metal layer composite flexible PCB plate connector. In this application, when the thickness of the metal conductive sheet layer 10 is set to 0.2mm, only holes with a minimum width of 0.3mm can be processed, that is, the minimum width of the design of the isolation part 11 is not less than 0.3mm.

[0044] In this embodiment, the coating layer 20 is an insulating material, including any one of polyethylene terephthalate, polycarbonate, polyimide, polyethylene terephthalate, and polypropylene.

[0045] According to the foregoing description, the thickness of the metal conductive sheet layer 10 is limited. Therefore, multiple layers of the metal conductive sheet layer 10 can be provided to achieve high current-carrying capacity. For example, Figure 5 As shown in, it is composed of two layers of the metal conductive sheet layer 10 laminated together. However, it is not limited to the two-layer structure shown in this figure, and it can also be three layers, four layers, or other numbers of layers according to design requirements.

[0046] Based on the structure of the flexible metal layer composite flexible PCB board connector described in this embodiment, taking the single-layer metal conductive sheet layer 10 as an example, this embodiment provides a processing technology for the flexible metal layer composite flexible PCB board connector, specifically as follows:

[0047] Select a metal conductive sheet layer 10 that meets the requirements;

[0048] According to the design requirements, perform material removal processing on the metal conductive sheet layer 10 to form the isolation part 11;

[0049] Use an insulating material to form the coating layer 20 outside the metal conductive sheet layer 10.

[0050] In the above process, selecting a metal conductive sheet layer 10 that meets the requirements means selecting a metal conductive sheet layer 10 with a certain thickness according to the design requirements. For example, the designed thickness of the metal conductive sheet layer 10 is 0.2 mm.

[0051] The material removal processing refers to removing the unnecessary part from a whole and continuous metal conductive sheet layer 10, and the remaining part is the required metal strip 12. It should be noted that after the material removal processing is completed, there is at least one connecting material 13 between adjacent metal strips 12 within the same flexible metal layer composite flexible PCB board connector. All the metal strips 12 are connected into a whole by the connecting material 13 to facilitate the integrity of the flexible metal layer composite flexible PCB board connector during the subsequent processing. For example, Figure 6 and Figure 7 As shown, it is a schematic structural diagram of the metal conductive sheet layer 10 after the material removal processing.

[0052] It should be noted that taking Figure 6For example, a three-in-one type of connector is shown, that is, one connector is respectively connected to three connectors through the flexible metal layer composite flexible PCB board connector, that is, different flexible metal layer composite flexible PCB board connectors have different numbers of branches. It is necessary to retain the connecting material 13 between adjacent metal strips 12 within the branch, and it is not necessary to retain the connecting material 13 between the metal strips 12 of adjacent branches.

[0053] One implementation method of the above-mentioned material removal process is the mechanical stamping material removal method, that is, a stamping die with a corresponding pattern is designed to stamp and remove the material from the metal conductive sheet layer 10 to obtain the metal strip 12 with the connecting material 13, and at the same time form the connecting hole 121 and the avoidance hole 122.

[0054] The forming method of the coating layer 20 is as follows: Place the metal strip 12 with the connecting material 13 on the backing plate, apply the insulating material and wait for it to cure, and then turn it over to apply the other side.

[0055] It should be noted that before applying the insulating material on the first side, the connecting material 13 needs to be removed. Usually, positioning pins corresponding to the connecting holes 121 are provided on the backing plate, and all the metal strips 12 are fixed on the backing plate through the positioning pins to maintain a complete state. On the other hand, the positioning pins can play an insulating role when applying the insulating material to prevent the insulating material from entering the connecting holes 121, which is not conducive to the electrical connection with components such as connectors in the later stage.

[0056] Of course, the method of forming the insulating material on the surface of the metal strip 12 is not limited to brushing, and can also be other methods such as spraying and dipping.

[0057] The flexible metal layer composite flexible PCB board connector described in this embodiment can be applied as follows:

[0058] (1) Single-piece use: According to the foregoing description, since the flexible metal layer composite flexible PCB board connector is used in narrow and restricted spaces, combined with the requirements of the processing technology for the thickness of the metal conductive sheet layer 10 and the width of the isolation part 11, on the premise of meeting the current-carrying requirements, a single-piece flexible metal layer composite flexible PCB board connector can be used to achieve the transmission of current and signals;

[0059] (2) Multi-piece stacking use: According to the foregoing description, the processing technology has requirements for the thickness of the metal conductive sheet layer 10 and the width of the isolation part 11. Therefore, the current-carrying capacity of the metal strip 12 in a single-piece flexible metal layer composite flexible PCB board connector has certain limitations. Under higher current-carrying requirements, multiple identical flexible metal layer composite flexible PCB board connectors can be stacked and used;

[0060] (3) Used in conjunction with flexible PCBs: As is well known, the application advantages of flexible PCBs include their high degree of integration. The width of a single copper foil inside can be as small as 0.05 μm. Therefore, more copper foils can be integrated in a flexible PCB of the same size. These copper foils can be used to achieve signal transmission, thus ensuring a high degree of integration of control signals. At the same time, the flexible metal layer composite flexible PCB board connector used in conjunction with the flexible PCB can give full play to its current-carrying advantage, and thus can simultaneously meet the requirements of high-density integrated signal transmission and large-current transmission. Moreover, the flexible metal layer composite flexible PCB board connector used in conjunction with the flexible PCB has a very small thickness and is suitable for realizing three-dimensional connections of electronic components at different positions in narrow and confined spaces.

[0061] Figure 8 and Figure 9 Fig. shows a schematic structural diagram of the flexible metal layer connector 100 used in conjunction with the flexible PCB connector 200, where Figure 8 Fig. shows a schematic diagram in the front view state, Figure 9 Fig. shows a three-dimensional exploded state schematic diagram. It can be seen that Figure 8 Fig. shows a one-to-three type of connector, that is, one output end corresponds to three input ends, or one input end corresponds to three output ends. It is not limited to this type and can also be other types. However, at least one connection end of the flexible metal layer connector 100 and the flexible PCB connector 200 is connected to the same component, so that the flexible metal layer connector 100 and the flexible PCB connector 200 have partial overlap, such as Figure 8 and 9 in, the four connection ends of the one-to-three type of connector are all overlapped, and connection holes and avoidance holes will also be provided on the corresponding flexible PCB connector 200.

[0062] Figure 10 Fig. shows a schematic structural diagram of the flexible metal layer connector 100 used in conjunction with the flexible PCB connector 200 in another embodiment. This connector is also a one-to-three type of connector, which involves the composite and overlapping use of the flexible metal layer connector 100 and the flexible PCB connector 200, such as Figure 10 in which two layers of flexible metal layer connectors 100 and three layers of flexible PCB connectors 200 are alternately overlapped and used.

[0063] The above embodiments are only used to illustrate the technical solutions of the present application and are not intended to limit them.

Claims

1. Flexible metal layer composite flexible PCB board connector, characterized in that, Comprising: A flexible metal layer connector, the flexible metal layer connector comprising metal strips that transmit large currents and are isolated from each other; And a flexible PCB connector that transmits high-density integrated signals; The flexible metal layer connector and the flexible PCB connector are partially or completely overlapped so that at least one connection end is connected to the same component.

2. The flexible metal layer composite flexible PCB board connector according to claim 1, wherein The metal strips are separated by hollowed-out isolation portions formed on a metal conductive sheet layer, and the metal conductive sheet layer is deformed by an external force and maintains the state of being deformed by the external force after the external force is withdrawn.

3. The flexible metal layer composite flexible PCB board connector according to claim 2, wherein It further includes a coating layer, the coating layer covers the outside of the metal conductive sheet layer, and the coating layer is embedded in the isolation portion to physically insulate and isolate adjacent metal strips.

4. The flexible metal layer composite flexible PCB board connector according to claim 1, wherein The metal strip has connection holes and / or avoidance holes.

5. The flexible metal layer composite flexible PCB board connector according to claim 2, characterized in that, The metal conductive sheet layer is a sheet made of any one of copper, gold, silver, molybdenum silicide, and chromium.

6. The flexible metal layer composite flexible PCB board connector according to claim 2, wherein The thickness of the metal conductive sheet layer does not exceed 0.2 mm, and the minimum width of the isolation portion is not less than 0.3 mm.

7. The flexible metal layer composite flexible PCB board connector according to claim 3, characterized in that, The coating layer is any one of polyethylene terephthalate, polycarbonate, polyimide, polyethylene glycol terephthalate, and polypropylene.

8. The flexible metal layer composite flexible PCB board connector according to claim 3, characterized in that Outside the metal conductive sheet layer covered by the coating layer is a single piece or multiple pieces stacked together.

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