Vehicle-mounted flexible impedance circuit board

Abstract

The utility model relates to a kind of vehicle-mounted flexible impedance circuit board.It solves the problem of poor heat dissipation and easy to cause signal reflection and crosstalk in the prior art vehicle-mounted flexible circuit board.It includes substrate combination layer, substrate combination layer lower end is provided with inner circuit structure layer and upper end is provided with outer circuit structure layer, inner circuit structure layer bottom is provided with inner protective film layer structure, outer circuit structure layer outside is provided with outer protective film layer structure.The utility model has the advantages of meeting the heat dissipation demand of vehicle-mounted circuit board, effectively reducing signal reflection and crosstalk, thereby improving the stability of signal transmission.

Description

Technical Field

[0001] This utility model relates to the field of circuit board technology, specifically to a vehicle-mounted flexible impedance circuit board. Background Technology

[0002] As automobiles evolve towards intelligence and electrification, electronic systems are becoming increasingly complex, with the proliferation of advanced driver assistance systems (ADAS) and in-vehicle infotainment systems. Traditional rigid circuit boards struggle to adapt to complex spatial layouts, while flexible circuit boards, with their bendable and foldable characteristics, can better fit the irregular spaces inside a car, providing flexible solutions for connecting electronic components.

[0003] Currently, in automotive lighting, especially automotive LED lights, the shape of the pads for automotive-specific LED lights differs from that of conventional LED lights. When soldering conventional flexible circuit boards (PCBs) to automotive-specific LED lights, manual positioning during the soldering process is required, making it impossible to accurately determine the position of the LED light pads on the PCB. This leads to soldering deviations, causing short circuits between the positive and negative terminals and affecting the lifespan of the circuit board. Furthermore, with the increasing application of high-speed signal transmission in automotive electronics, such as high-speed data buses, automotive display systems, and radio frequency signal transmission, the requirements for signal integrity are increasing. Traditional flexible circuit boards struggle to meet the heat dissipation requirements of diverse automotive system data transmission and are prone to signal reflection and crosstalk, affecting signal transmission stability.

[0004] To address the shortcomings of existing technologies, people have conducted long-term explorations and proposed various solutions. For example, Chinese patent literature discloses a precisely positioned vehicle-mounted flexible circuit board [CN201821513162.5], which includes a flexible circuit board body, positive and negative electrode pads, and a positioning plate. The positioning plate includes a first positioning plate and a second positioning plate, and the positive and negative electrode pads include a first positive and negative electrode pad and a second positive and negative electrode pad. The first positive and negative electrode pads are fixedly disposed on the upper surface of the flexible circuit board body, and the second positive and negative electrode pads are fixedly disposed on the lower surface. The positioning plate has a plurality of positioning holes for the positive and negative electrode pads to pass through. The positive and negative electrode pads pass through the positioning holes and are connected to the flexible circuit board body. The height of the positioning plate is higher than that of the positive and negative electrode pads.

[0005] The above solution has solved the problems of inconvenient installation of flexible circuit boards and easy soldering deviation in the existing technology to a certain extent. However, the solution still has many shortcomings, such as: it is difficult to meet the heat dissipation requirements of data transmission in the diversified automotive system, and it is easy to cause signal reflection and crosstalk, affecting the stability of signal transmission. Summary of the Invention

[0006] The purpose of this invention is to address the above-mentioned problems by providing a vehicle-mounted flexible impedance circuit board.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: a vehicle-mounted flexible impedance circuit board, comprising a substrate assembly layer, an inner circuit structure layer at the lower end of the substrate assembly layer and an outer circuit structure layer at the upper end, an inner protective film layer at the bottom of the inner circuit structure layer, and an outer protective film layer on the outer side of the outer circuit structure layer.

[0008] In the aforementioned automotive flexible impedance circuit board, the substrate assembly layer includes a PI middle film layer, and AD adhesive layers are disposed on the upper and lower sides of the PI middle film layer. The AD adhesive layers on the upper and lower sides are circumferentially connected by flexible positioning connection layers. The PI middle film layer is connected to the outer circuit structure layer and the inner circuit structure layer through the AD adhesive layers on the upper and lower sides, respectively.

[0009] In the aforementioned vehicle-mounted flexible impedance circuit board, a positioning frame groove is provided on the inner wall of the flexible positioning connection layer, and the film layer in PI is circumferentially positioned within the positioning frame groove.

[0010] In the aforementioned vehicle-mounted flexible impedance circuit board, the outer protective film layer structure includes a PI outer protective film layer, an outer AD adhesive layer is disposed on the underside of the PI outer protective film layer, and an insulating layer is disposed on the side of the outer AD adhesive layer away from the PI outer protective film layer, with the insulating layer in contact with the outer circuit structure layer.

[0011] In the aforementioned vehicle-mounted flexible impedance circuit board, a pressure-bearing layer is provided between the outer AD adhesive layer and the PI outer protective film layer.

[0012] In the aforementioned vehicle-mounted flexible impedance circuit board, the inner protective film layer structure includes an inner PI protective film layer, an inner AD adhesive layer is disposed on the upper side of the inner PI protective film layer, and a heat dissipation layer is disposed on the side of the inner AD adhesive layer away from the inner PI protective film layer.

[0013] In the aforementioned vehicle-mounted flexible impedance circuit board, a heat-conducting seat is provided on the circumferential side of the heat dissipation layer. The heat-conducting seat is in circumferential contact with the inner AD adhesive layer and the inner PI protective film layer, and several equidistantly arranged micro heat dissipation fins are inserted into the heat-conducting seat.

[0014] In the aforementioned vehicle-mounted flexible impedance circuit board, a pure copper layer is disposed between the inner circuit structure layer and the heat dissipation layer, and the pure copper layer is connected to the inner circuit structure layer through a thermosetting adhesive layer.

[0015] In the aforementioned vehicle-mounted flexible impedance circuit board, a support base is embedded within the thermosetting adhesive layer, and the pure copper layer, the support base, and the thermosetting adhesive layer are circumferentially sealed by a sealing film.

[0016] In the aforementioned vehicle-mounted flexible impedance circuit board, several heat dissipation micropores are provided between the PI film layer and the AD adhesive layers located on the upper and lower sides.

[0017] Compared with the prior art, the advantages of this utility model are as follows: This application improves heat dissipation performance by using a heat dissipation layer, a heat-conducting seat, and micro heat dissipation fins in the protective film structure, in conjunction with a pure copper layer between the inner circuit structure layer and the heat dissipation layer; secondly, heat dissipation micropores are provided between the PI film layer and the upper and lower AD adhesive layers, and heat dissipation is enhanced through multiple paths to meet the heat dissipation requirements of diversified automotive system data transmission; at the same time, the insulating layer of the outer protective film layer can reduce signal interference, and the flexible positioning connection layer accurately positions the PI film layer through the positioning frame groove, combined with the thermosetting adhesive layer embedded support seat and circumferential sealing film to ensure structural stability, avoid line deviation, effectively reduce signal reflection and crosstalk, thereby improving the stability of signal transmission. Attached Figure Description

[0018] Figure 1 This is a cross-sectional view of the overall structure of this utility model; Figure 2 This is a detailed structural diagram of the substrate assembly layer in this utility model; Figure 3 This is a schematic diagram of the outer protective film layer structure in this utility model; Figure 4 This is a schematic diagram of the inner protective film layer structure in this utility model; Figure 5 This is a schematic diagram of the pure copper layer and thermosetting adhesive layer structure in this utility model; In the figure: substrate assembly layer 1, PI middle film layer 11, AD adhesive layer 12, flexible positioning connection layer 13, positioning frame groove 14, heat dissipation micro-hole 15, inner circuit structure layer 2, outer circuit structure layer 3, inner protective film layer structure 4, inner PI protective film layer 41, inner AD adhesive layer 42, heat dissipation layer 43, heat conduction base 44, micro heat dissipation fins 45, outer protective film layer structure 5, PI outer protective film layer 51, outer AD adhesive layer 52, insulating layer 53, pressure bearing layer 54, pure copper layer 6, thermosetting adhesive layer 7, support base 71, sealing film 72. Detailed Implementation

[0019] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0020] like Figure 1-5 As shown, the vehicle-mounted flexible impedance circuit board includes a substrate assembly layer 1, an inner circuit structure layer 2 at the lower end of the substrate assembly layer 1 and an outer circuit structure layer 3 at the upper end, an inner protective film layer structure 4 at the bottom of the inner circuit structure layer 2, and an outer protective film layer structure 5 on the outside of the outer circuit structure layer 3.

[0021] The substrate assembly layer 1 includes a PI intermediate film layer 11, with AD adhesive layers 12 disposed on the upper and lower sides of the PI intermediate film layer 11. The AD adhesive layers 12 on the upper and lower sides are connected circumferentially by a flexible positioning connection layer 13. The PI intermediate film layer 11 is connected to the outer circuit structure layer 3 and the inner circuit structure layer 2 through the AD adhesive layers 12 on the upper and lower sides, respectively.

[0022] In the PI film layer 11, the upper outer circuit structure layer 3 and the lower inner circuit structure layer 2 are stably bonded to each other through the upper and lower AD adhesive layers 12, respectively, ensuring a tight bond between the circuit layer and the substrate.

[0023] As can be seen, the inner wall of the flexible positioning connection layer 13 is provided with a positioning frame groove 14, and the PI film layer 11 is circumferentially positioned in the positioning frame groove 14.

[0024] The circumferential positioning of the film layer 11 in the PI is within the positioning frame groove 14, which can effectively limit the offset of the film layer 11 in the PI, provide a reference for the precise layout of subsequent external and internal circuits, and avoid the impact of circuit function due to substrate displacement.

[0025] Furthermore, the outer protective film layer structure 5 includes a PI outer protective film layer 51, an outer AD adhesive layer 52 is disposed on the lower side of the PI outer protective film layer 51, and an insulating layer 53 is disposed on the side of the outer AD adhesive layer 52 away from the PI outer protective film layer 51, and the insulating layer 53 is in contact with the outer circuit structure layer 3.

[0026] Specifically, a pressure-bearing layer 54 is provided between the outer AD adhesive layer 52 and the PI outer protective film layer 51.

[0027] The outer line structure layer 3 serves as the upper signal transmission carrier, and its outer protective film layer structure 5 mainly performs protection and anti-interference functions. In the outer protective film layer structure 5, the PI outer protective film layer 51 is the outer basic protective layer, used to isolate the line from external environmental erosion; The outer AD adhesive layer 52 is used to bond the PI outer protective film layer 51 to the underlying insulating layer 53, while the insulating layer 53 is in direct contact with the outer circuit structure layer 3, reducing the interference of external signals on the outer circuit structure layer 3 and reducing the risk of signal crosstalk. In addition, the pressure-bearing layer 54 between the outer AD adhesive layer 52 and the PI outer protective film layer 51 can enhance the compression resistance of the outer protective film layer structure 5 and prevent the outer circuit from being damaged by external pressure.

[0028] Furthermore, the inner protective film layer structure 4 includes an inner PI protective film layer 41, an inner AD adhesive layer 42 is disposed on the upper side of the inner PI protective film layer 41, and a heat dissipation layer 43 is disposed on the side of the inner AD adhesive layer 42 away from the inner PI protective film layer 41.

[0029] More specifically, a heat-conducting seat 44 is provided on the circumferentially downward side of the heat dissipation layer 43. The heat-conducting seat 44 is in circumferential contact with the inner AD adhesive layer 42 and the inner PI protective film layer 41, and a number of equidistantly arranged micro heat dissipation fins 45 are inserted into the heat-conducting seat 44.

[0030] The inner circuit structure layer 2 serves as the lower signal transmission carrier. In the inner protective film layer structure 5, the inner PI protective film layer 41 provides basic inner protection. The heat dissipation layer 43 is bonded to the upper inner AD adhesive layer 42. The heat dissipation layer 43 can directly absorb the heat generated by the inner circuit structure layer 2. Furthermore, the heat dissipation layer 43 is in circumferential contact with the heat-conducting base 44 on the lower side, as well as the inner AD adhesive layer 42 and the inner PI protective film layer 41, which can conduct the heat of the heat dissipation layer 43 to itself. Then, through several equidistant micro heat dissipation fins 45 inserted on the heat-conducting base 44, the heat dissipation area is increased, and the heat is quickly dissipated to the outside. At the same time, the pure copper layer 6 between the inner circuit structure layer 2 and the heat dissipation layer 43 utilizes the high thermal conductivity of pure copper to further improve the heat conduction efficiency of the inner circuit structure layer 2 to the heat dissipation layer 43, thereby enhancing the heat dissipation effect.

[0031] In detail, a pure copper layer 6 is provided between the inner circuit structure layer 2 and the heat dissipation layer 43, and the pure copper layer 6 is connected to the inner circuit structure layer 2 through a thermosetting adhesive layer 7.

[0032] Preferably, a support base 71 is embedded in the thermosetting adhesive layer 7, and the pure copper layer 6, the support base 71 and the thermosetting adhesive layer 7 are circumferentially sealed by a sealing film 72.

[0033] The support base 71 embedded in the thermosetting adhesive layer 7 can enhance the structural strength of the connection between the pure copper layer 6 and the inner circuit structure layer 2, and prevent the connection from loosening due to thermal expansion and contraction during long-term use; the sealing film 72 around the pure copper layer 6, the support base 71 and the thermosetting adhesive layer 7 can achieve closed protection and isolate the internal structure from the corrosion of external impurities such as water vapor and dust.

[0034] In addition, several heat dissipation micropores 15 are provided between the PI film layer 11 and the AD adhesive layers 12 located on the upper and lower sides.

[0035] The heat dissipation microholes 15 between the PI film layer 11 and the upper and lower AD adhesive layers 12 can assist in heat dissipation of the substrate assembly layer 1, avoid the substrate itself from being affected by heat accumulation, and further ensure the stable operation of the circuit board as a whole.

[0036] In summary, the principle of this embodiment is as follows: the flexible positioning connection layer 13 uses the inner wall positioning frame groove 14 to limit the circumferential positioning of the PI film layer 11, thereby achieving precise positioning of the overall structure; the outer side of the outer circuit structure layer 3 is protected by the outer protective film layer structure 5, and the PI outer protective film layer 51 is bonded to the insulating layer 53 through the outer AD adhesive layer 12 to reduce signal interference, and the pressure-bearing layer 54 enhances the compression resistance. The bottom of the inner circuit structure layer 2 is protected by the inner protective film layer 4 for heat dissipation. The inner PI protective film layer 41 is bonded to the heat dissipation layer 43 through the inner AD adhesive layer 42. The heat conduction seat 44 and the inserted micro heat dissipation fins 45 in the circumferential direction of the heat dissipation layer 43 accelerate heat dissipation. The pure copper layer 6 between the inner circuit structure layer 2 and the heat dissipation layer 43 is connected by the thermosetting adhesive layer 7 to improve the heat conduction efficiency. The support seat 71 embedded in the thermosetting adhesive layer 7 enhances the connection stability. The pure copper layer 6, the support seat 71 and the thermosetting adhesive layer 7 in the circumferential direction of the sealing film 72 achieve closed protection. The heat dissipation microholes 15 between the PI film layer 11 and the upper and lower AD adhesive layers 12 assist the substrate assembly layer 1 in heat dissipation, thereby achieving the purpose of precise positioning, anti-interference of external circuits, and efficient heat dissipation of internal circuits on the circuit board.

[0037] The specific embodiments described herein are merely illustrative examples illustrating the spirit of this utility model. Those skilled in the art to which this utility model pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of this utility model or exceeding the scope defined by the appended claims.

[0038] Although this document frequently uses terms such as substrate assembly layer 1, PI middle film layer 11, AD adhesive layer 12, flexible positioning connection layer 13, positioning frame groove 14, heat dissipation micro-hole 15, inner circuit structure layer 2, outer circuit structure layer 3, inner protective film layer structure 4, inner PI protective film layer 41, inner AD adhesive layer 42, heat dissipation layer 43, heat-conducting base 44, micro heat dissipation fins 45, outer protective film layer structure 5, PI outer protective film layer 51, outer AD adhesive layer 52, insulating layer 53, pressure-bearing layer 54, pure copper layer 6, thermosetting adhesive layer 7, support base 71, and sealing film 72, the possibility of using other terms is not excluded. The use of these terms is merely for the convenience of describing and explaining the essence of this utility model; interpreting them as any additional limitation would contradict the spirit of this utility model.

Claims

1. A vehicle-mounted flexible impedance circuit board, comprising a substrate assembly layer (1), characterized in that, The substrate assembly layer (1) has an inner circuit structure layer (2) at the lower end and an outer circuit structure layer (3) at the upper end. The inner circuit structure layer (2) has an inner protective film layer structure (4) at the bottom and the outer circuit structure layer (3) has an outer protective film layer structure (5) on the outside.

2. The vehicle-mounted flexible impedance circuit board according to claim 1, characterized in that, The substrate assembly layer (1) includes a PI middle film layer (11), and AD adhesive layers (12) are provided on the upper and lower sides of the PI middle film layer (11). The AD adhesive layers (12) on the upper and lower sides are connected circumferentially by a flexible positioning connection layer (13). The PI middle film layer (11) is connected to the outer circuit structure layer (3) and the inner circuit structure layer (2) through the AD adhesive layers (12) on the upper and lower sides respectively.

3. The vehicle-mounted flexible impedance circuit board according to claim 2, characterized in that, The flexible positioning connection layer (13) has a positioning frame groove (14) on its inner wall, and the PI film layer (11) is circumferentially positioned in the positioning frame groove (14).

4. The vehicle-mounted flexible impedance circuit board according to claim 1, characterized in that, The outer protective film layer structure (5) includes a PI outer protective film layer (51), an outer AD adhesive layer (52) is provided on the lower side of the PI outer protective film layer (51), and an insulating layer (53) is provided on the side of the outer AD adhesive layer (52) away from the PI outer protective film layer (51). The insulating layer (53) is in contact with the outer circuit structure layer (3).

5. The vehicle-mounted flexible impedance circuit board according to claim 4, characterized in that, A pressure-bearing layer (54) is provided between the outer AD adhesive layer (52) and the outer PI protective film layer (51).

6. The vehicle-mounted flexible impedance circuit board according to claim 1, characterized in that, The inner protective film layer structure (4) includes an inner PI protective film layer (41), an inner AD adhesive layer (42) is provided on the upper side of the inner PI protective film layer (41), and a heat dissipation layer (43) is provided on the side of the inner AD adhesive layer (42) away from the inner PI protective film layer (41).

7. The vehicle-mounted flexible impedance circuit board according to claim 6, characterized in that, The heat dissipation layer (43) is provided with a heat conduction seat (44) on the circumferential side. The heat conduction seat (44) is in circumferential contact with the inner AD adhesive layer (42) and the inner PI protective film layer (41). A number of micro heat dissipation fins (45) are inserted into the heat conduction seat (44) at equal intervals.

8. The vehicle-mounted flexible impedance circuit board according to claim 7, characterized in that, A pure copper layer (6) is provided between the inner circuit structure layer (2) and the heat dissipation layer (43), and the pure copper layer (6) is connected to the inner circuit structure layer (2) through a thermosetting adhesive layer (7).

9. The vehicle-mounted flexible impedance circuit board according to claim 8, characterized in that, The thermosetting adhesive layer (7) is embedded with a support base (71), and the pure copper layer (6), the support base (71) and the thermosetting adhesive layer (7) are circumferentially sealed by a sealing film (72).

10. The vehicle-mounted flexible impedance circuit board according to claim 2, characterized in that, A number of heat dissipation micropores (15) are provided between the PI film layer (11) and the AD adhesive layer (12) located on the upper and lower sides.

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