New energy automobile sensor circuit board assembly

Abstract

The invention relates to the technical field of circuit boards, in particular to a new energy automobile sensor circuit board assembly which comprises a flexible base material, the flexible base material is constructed to comprise a bearing wire, a conductive element and a flexible film covering structure, and the flexible film covering structure covers the bearing wire and the conductive element; and a plurality of discretely distributed hard component welding islands connected to the first surface and / or the second surface of the flexible substrate. According to the circuit board assembly, limit adaptation of space is achieved through cooperation of the flexible base material and the hard component welding island, the hard island area ensures welding reliability of the chip through the rigid carrier, meanwhile, the flexible base body embedded with the aramid yarn can prevent the wire from generating deformation stress, the circuit board can be attached to the special-shaped cavity without damaging electrical connection, and the circuit board assembly is suitable for being used in the special-shaped cavity. And the two sealing glue layers are sequentially arranged outside the chip, so that good heat dissipation and vibration resistance can be maintained.

Description

Technical Field

[0001] The present invention relates to the technical field of circuit boards, and in particular to a new energy vehicle sensor circuit board assembly. Background Art

[0002] With the rapid popularization of the 800V high-voltage architecture of new energy vehicles, multi-parameter monitoring circuits such as temperature and impedance need to be integrated into high-voltage connectors. Their circuit boards must take into account high-density wiring, reliable chip installation, and tolerance to extreme working conditions within millimeter-level special-shaped cavities. Among the current mainstream solutions, rigid segmented circuits are difficult to adapt to curved cavity structures due to physical size limitations, and the connection parts are prone to fatigue failure under mechanical vibration conditions. Although pure flexible circuits have the ability to deform, the mechanical stability of the welding areas of key components is insufficient, and repeated deformation may lead to reduced electrical connection reliability. In addition, single-layer sealing materials are prone to bubbles when filling complex micro-gaps, affecting the uniformity of heat dissipation, and the interface adhesion strength decays significantly after long-term thermal cycling.

[0003] As mentioned above, existing circuit architectures face the challenge of multi-physical field coupling: the mechanical properties of the substrate make it difficult to balance local rigid support and overall deformation adaptability; the sealing process is difficult to achieve defect-free filling at the submillimeter scale, resulting in limited thermal management efficiency; there is a design contradiction between the impedance stability and mechanical shock resistance of the conductive circuit under dynamic conditions.

[0004] These factors jointly restrict the long-term reliability of the monitoring circuits in high-voltage connectors in extreme temperature, vibration and electromagnetic interference environments. The industry urgently needs to break through the limitations of traditional single material systems. Summary of the Invention

[0005] In response to the technical problems existing in the circuit board in the prior art, the present invention proposes a new energy vehicle sensor circuit board assembly, comprising: A flexible substrate, the flexible substrate being constructed to include a tensile wire material, a conductive element, and a flexible coating structure, wherein the flexible coating structure covers the tensile wire material and the conductive element; a plurality of discretely distributed hard component welding islands connected to the first surface and / or the second surface of the flexible substrate, each of the hard component welding islands being used to carry a target component, with a gap region being formed between two adjacent hard component welding islands; Wherein, in the gap area, the conductive elements are distributed in a serpentine shape, and both ends of the conductive elements are electrically connected to the hard component welding islands, respectively, for achieving electrical connection between target components carried on two adjacent hard component welding islands, and the tensile wire is connected to the two adjacent hard component welding islands; A bonding area is formed in adjacent areas of the plurality of gap areas. An opening is provided in the bonding area. The opening passes through the first surface and the second surface of the flexible substrate.

[0006] Preferably, the tensile wire material includes aramid tows, which are distributed along the shortest path between adjacent welding islands of the hard components. The conductive element includes metal wire or metal foil. In the same gap area, the length of the conductive element is more than 130% of the length of the aramid tow.

[0007] Preferably, the flexible coating structure comprises a polyimide film, the tensile wire material and the conductive element constitute a routing layer, and the polyimide film is coated on the outer layer of the routing layer at least in the gap area.

[0008] Preferably, the hard component welding island includes a high-frequency FR4 substrate, an edge of the high-frequency FR4 substrate is provided with an edge sealing structure, and the aramid tow is connected to the edge sealing structure.

[0009] Preferably, the edge sealing structure comprises a copper edge sealing structure, and the contact surface between the edge sealing structure and the high-frequency FR4 substrate is a serrated surface.

[0010] Preferably, the surface of the hard component welding island is provided with a packaging area for carrying target components, and the hard component welding island is provided with a first sealing layer that completely covers the packaging area, and a second sealing layer is provided on the outer layer of the first sealing layer, and the hardness of the first sealing layer is greater than the hardness of the second sealing layer.

[0011] Preferably, the first sealing layer is constructed as a frustum-shaped structure, the second sealing layer of equal thickness covers at least the sidewall of the first sealing layer, and the axis of the first sealing layer is perpendicular to the surface of the hard component welding island.

[0012] Preferably, the sidewall inclination angle of the first sealing layer is 45° to 60°, the first sealing layer comprises a silicone rubber structure layer filled with thermally conductive particles, and the second sealing layer comprises a bubble structure layer.

[0013] Preferably, the area of ​​the openings accounts for 8% to 12% of the total area of ​​the flexible substrate.

[0014] Preferably, the plurality of hard component welding islands are distributed in a matrix shape, and the hard component welding islands are rectangular or circular, or the plurality of hard component welding islands are distributed in a honeycomb shape, and each hard component welding island is hexagonal or circular.

[0015] Compared with the prior art, the advantages of the present invention are: The circuit board assembly of the present application achieves extreme spatial adaptation through the combination of a flexible substrate and a hard component welding island. The hard island area uses a rigid carrier to ensure the chip welding reliability. At the same time, the flexible matrix embedded with aramid fibers can avoid deformation stress in the wires, so that the circuit board can fit into the special-shaped cavity without damaging the electrical connection. The two layers of sealing glue arranged in sequence outside the chip can maintain good heat dissipation and vibration resistance. The distributed hard island layout and staggered openings synergistically optimize the mechanical strength and glue filling channels, which can adapt to complex and narrow cavities and still meet the requirements of vibration resistance, heat cycle resistance and high-voltage isolation while maintaining an ultra-thin form. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings are not intended to be drawn to scale. In the drawings, each identical or nearly identical component shown in various figures may be represented by the same reference numeral. For the sake of clarity, not every component is labeled in every figure. Embodiments of various aspects of the present invention will now be described by way of example and with reference to the accompanying drawings, in which: Figure 1 This is a schematic diagram of a circuit board installed in a small space in the prior art; Figure 2 This is a schematic diagram of the new energy vehicle sensor circuit board assembly shown in the present invention installed in a small space; Figure 3 This is a structural diagram of the new energy vehicle sensor circuit board assembly shown in the present invention; Figure 4 Schematic diagram of the distribution of the tensile wire and the conductive elements shown in the present invention; Figure 5 It is a structural schematic diagram of the outer sealing layer of the hard component welding island shown in the present invention. DETAILED DESCRIPTION

[0017] In order to better understand the technical content of the present invention, specific embodiments are given and described below with reference to the accompanying drawings.

[0018] like Figure 1 As shown, when facing installation in a small space, the maximum size L2 of the smallest space often determines the maximum size of the circuit board L1, and when the installation space is irregular in shape, it is even more difficult to match the size of the circuit board. For example, the existing rigid PCB board cannot adapt to the curved cavity less than 5mm in the fast charging gun head. Although the flexible circuit board can be bent to fit the cavity, the solder joints are easily deformed or even desoldered under bending stress.

[0019] Therefore, the present application aims to propose a sensor circuit board assembly that is both rigid and flexible, such as Figure 2As shown, the sensor circuit board assembly can be bent and folded according to the shape of the cavity, but the mounting area of ​​the target component 50 is a hard structure, which will not cause the solder joints to fall off due to stress. The actual unfolded size of the circuit board can be larger than the installation size L3. During installation, the circuit board assembly can be compressed, and its outer contour L4 can be smaller than L3 for installation, meeting the chip installation rigidity requirements and cavity deformation tracking capabilities in millimeter-level special-shaped spaces.

[0020] like Figures 3 to 5 As shown, the present invention proposes a new energy vehicle sensor circuit board assembly, which mainly includes a flexible substrate 102 and a plurality of discretely distributed hard component welding islands 101 arranged on the flexible substrate 102.

[0021] The flexible substrate 102 is constructed to include a tensile wire 31, a conductive element 32, and a flexible coating structure, wherein the flexible coating structure covers the tensile wire 31 and the conductive element 32. A plurality of discretely distributed hard component welding islands 101 are connected to the first surface and / or the second surface of the flexible substrate 102, wherein each hard component welding island 101 is used to carry a target component 50, and a gap region 103 is formed between two adjacent hard component welding islands 101.

[0022] In this way, the hard component welding island 101 can provide a hard load area for the target component 50. Compared with the flexible circuit board, under the stress caused by bending and extrusion, the solder joints of the target component 50 are subjected to less force and are not easy to desolder. At the same time, the flexible coating structure can provide flexible connections for adjacent hard component welding islands 101, so that the adjacent hard component welding islands 101 can be distributed in a smaller position according to the actual installation space, such as a suitable folding and bending state.

[0023] Furthermore, in the gap area 103, the conductive element 32 is distributed in a serpentine shape, and the two ends of the conductive element 32 are respectively electrically connected to the hard component welding island 101, so as to realize the electrical connection between the target components 50 carried on the two adjacent hard component welding islands 101, and the tensile wire 31 is connected to the two adjacent hard component welding islands 101.

[0024] In this way, the tensile stress between the two hard component welding islands 101 is borne by the tensile wire 31 to ensure that the structures will not separate from each other, and the conductive elements 32 are distributed in a serpentine shape, which can effectively avoid pulling and breaking caused by bending and twisting, and ensure the reliability of electrical signal transmission.

[0025] In an optional embodiment, the tensile wire 31 includes an aramid tow, which is distributed along the shortest path between adjacent hard component welding islands 101. The conductive element 32 includes a metal wire or a metal foil, such as a copper wire or a copper foil. In the same gap area 103, the length of the conductive element 32 is more than 130% of the length of the aramid tow.

[0026] In this way, the length of the gap between the two hard component welding islands 101 is limited by the aramid yarn bundle, that is, the conductive element 32 is prevented from being stretched.

[0027] like Figure 5 As shown, in the above embodiment, the flexible coating structure can be a polyimide film 20 , and the wiring layer 30 is composed of a tensile wire 31 and a conductive element 32 . The polyimide film 20 is coated on the outer layer of the wiring layer 30 at least in the gap area 103 .

[0028] That is, in the gap area 103, the wiring layer 30 structure (the tensile wire 31 and the conductive element 32) is always covered by the polyimide film 20 to prevent it from being exposed, thereby protecting the wiring layer 30 structure. The polyimide film 20 has extreme temperature resistance and can meet the fast charging high temperature peak requirement of 150°C. At the same time, the polyimide film 20 has good elongation at break and can cooperate with the aramid tow to withstand bending.

[0029] In an optional embodiment, a thermally conductive silicone layer 10 is provided on the bottom layer of the polyimide film 20 to provide protection and conduct heat.

[0030] Furthermore, the hard component welding island 101 includes a high-frequency FR4 substrate 40 , an edge of the high-frequency FR4 substrate 40 is provided with an edge sealing structure, and the aramid tow is connected to the edge sealing structure.

[0031] The high-frequency FR4 substrate 40 has the characteristics of high frequency and low loss, and has high bending strength and can provide compressive support.

[0032] In this way, the aramid tow is fixed by high-temperature pressing the edge sealing structure and the high-frequency FR4 substrate 40, which can effectively improve the integrity of the structural connection.

[0033] Optionally, the edge sealing structure includes a copper edge sealing structure, and the contact surface between the edge sealing structure and the high-frequency FR4 substrate 40 is a serrated surface. The serrated surface can more effectively improve the connection strength of the aramid tow.

[0034] Combine Figure 4 and Figure 5As shown, the surface of the hard component welding island 101 is provided with a packaging area 105 for carrying the target component 50, and the hard component welding island 101 is provided with a first sealing layer 60 that completely covers the packaging area 105, and a second sealing layer 70 is provided on the outer layer of the first sealing layer 60, and the hardness of the first sealing layer 60 is greater than the hardness of the second sealing layer 70.

[0035] The first sealing layer 60 is intended to protect the target electrical components in the packaging area 105 and improve the outward heat diffusion capability of the electrical components through complete bonding, while the second sealing layer 70 is intended to achieve vibration buffering.

[0036] In an optional embodiment, the first sealing layer 60 is constructed as a frustum-shaped structure, the second sealing layer 70 of equal thickness covers at least the side wall of the first sealing layer 60, and the axis of the first sealing layer 60 is perpendicular to the surface of the hard component welding island 101.

[0037] Specifically, the sidewall inclination angle of the first sealing layer 60 is 45°~60°, the first sealing layer 60 includes a silicone rubber structure layer filled with thermal conductive particles, for example, graphene or boron nitride particles are filled in the silicone rubber structure layer, and the second sealing layer 70 includes a bubble structure layer.

[0038] In this way, the provision of thermally conductive particles is conducive to the heat transfer outward from components.

[0039] like Figure 4 As shown, a bonding area 104 is formed in adjacent areas of the plurality of gap areas 103 . An opening 80 is provided in the bonding area 104 . The opening 80 passes through the first surface and the second surface of the flexible substrate 102 .

[0040] Thus, through the design of the opening 80, after the circuit board assembly is filled into the predetermined installation space, it is advantageous for the structural adhesive to fill the entire space during the glue pouring process, thereby avoiding the generation of air gaps and improving the heat dissipation capability.

[0041] Optionally, the area of ​​the opening 80 accounts for 8% to 12% of the total area of ​​the flexible substrate 102. If the opening is too small, bubbles may remain during the glue pouring process, while if the opening is too large, the strength of the structure may be reduced.

[0042] In the above embodiment, the plurality of hard component welding islands 101 are distributed in a matrix, and the hard component welding islands 101 are rectangular or circular.

[0043] In other embodiments, the plurality of hard component welding islands 101 are distributed in a honeycomb shape, and each hard component welding island 101 is hexagonal or circular.

[0044] In an optional embodiment, the size of the hard component welding island 101 is 0.5 mm larger than the target electrical component, and the spacing between the hard component welding islands 101 can be adjusted according to the shape and curvature of the installation space, and is approximately 1.5~2 mm. The thickness of the polyimide film 20 is approximately 50 microns, of which the diameter of the aramid yarn bundle is 20 microns. The aramid yarn bundle can be laser welded to the connecting surface of the copper block and the high-frequency FR4 substrate 40.

[0045] In combination with the above embodiments, the circuit board assembly of the present application achieves extreme spatial adaptation through the cooperation of a flexible substrate and a hard component welding island. The hard island area uses a rigid carrier to ensure the chip welding reliability. At the same time, the flexible matrix embedded with aramid silk can avoid deformation stress in the wire, so that the circuit board can fit the special-shaped cavity without damaging the electrical connection. The two layers of sealing glue arranged in sequence outside the chip can maintain good heat dissipation and vibration resistance. The distributed hard island layout and staggered openings synergistically optimize the mechanical strength and glue filling channels, which can adapt to complex and narrow cavities and can still meet the requirements of vibration resistance, heat cycle resistance and high-voltage isolation while maintaining an ultra-thin form.

[0046] While the present invention has been disclosed above with reference to preferred embodiments, this is not intended to limit the present invention. Persons skilled in the art will readily appreciate that various modifications and variations can be made without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the claims.

Claims

1. A new energy vehicle sensor circuit board assembly, characterized in that: include: A flexible substrate (102), the flexible substrate (102) being constructed to include a tensile wire material (31), a conductive element (32), and a flexible coating structure, wherein the flexible coating structure covers the tensile wire material (31) and the conductive element (32); A plurality of discretely distributed hard component welding islands (101) connected to the first surface and / or the second surface of the flexible substrate (102), each of the hard component welding islands (101) being used to carry a target component (50), and a gap region (103) being formed between two adjacent hard component welding islands (101); Wherein, in the gap area (103), the conductive elements (32) are distributed in a serpentine shape, and both ends of the conductive elements (32) are electrically connected to the hard component welding islands (101) respectively, so as to realize electrical connection between the target components (50) carried on two adjacent hard component welding islands (101), and the tensile wire (31) is connected to the two adjacent hard component welding islands (101); A bonding area (104) is formed in adjacent areas of the plurality of gap areas (103), wherein an opening (80) is provided in the bonding area (104), and the opening (80) penetrates the first surface and the second surface of the flexible substrate (102).

2. A new energy vehicle sensor circuit board assembly according to claim 1, characterized in that: The tensile wire material (31) includes an aramid bundle, and the aramid bundle is distributed along the shortest path between adjacent hard component welding islands (101). The conductive element (32) includes a metal wire or a metal foil. In the same gap area (103), the length of the conductive element (32) is more than 130% of the length of the aramid bundle.

3. A new energy vehicle sensor circuit board assembly according to claim 1, characterized in that: The flexible coating structure includes a polyimide film (20), a wiring layer (30) formed by the tensile wire (31) and the conductive element (32), and the polyimide film (20) is coated on the outer layer of the wiring layer (30) at least in the gap area (103).

4. A new energy vehicle sensor circuit board assembly according to claim 2, characterized in that: The hard component welding island (101) comprises a high-frequency FR4 substrate (40), an edge of the high-frequency FR4 substrate (40) is provided with an edge sealing structure, and the aramid filament bundle is connected to the edge sealing structure.

5. A new energy vehicle sensor circuit board assembly according to claim 4, characterized in that: The edge sealing structure comprises a copper edge sealing structure, and the contact surface between the edge sealing structure and the high-frequency FR4 substrate (40) is a serrated surface.

6. A new energy vehicle sensor circuit board assembly according to claim 1, characterized in that: The surface of the hard component welding island (101) is provided with a packaging area (105) for carrying a target component (50), and the hard component welding island (101) is provided with a first sealing layer (60) that completely covers the packaging area (105), and a second sealing layer (70) is provided on the outer layer of the first sealing layer (60), and the hardness of the first sealing layer (60) is greater than the hardness of the second sealing layer (70).

7. A new energy vehicle sensor circuit board assembly according to claim 6, characterized in that: The first sealing layer (60) is constructed as a frustum-shaped structure, the second sealing layer (70) has a constant thickness and covers at least the side wall of the first sealing layer (60), and the axis of the first sealing layer (60) is perpendicular to the surface of the hard component welding island (101).

8. The new energy vehicle sensor circuit board assembly according to claim 6, characterized in that: The sidewall inclination angle of the first sealing glue layer (60) is 45° to 60°. The first sealing glue layer (60) comprises a silicone rubber structure layer filled with heat-conducting particles, and the second sealing glue layer (70) comprises a bubble structure layer.

9. The new energy vehicle sensor circuit board assembly according to claim 1, characterized in that: The area of ​​the opening (80) accounts for 8% to 12% of the total area of ​​the flexible substrate (102).

10. A new energy vehicle sensor circuit board assembly according to any one of claims 1 to 9, characterized in that: The plurality of hard component welding islands (101) are distributed in a matrix shape, and the hard component welding islands (101) are rectangular or circular, or the plurality of hard component welding islands (101) are distributed in a honeycomb shape, and each hard component welding island (101) is hexagonal or circular.

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