Curved-surface-attached flexible circuit board antenna

Abstract

The utility model discloses a curved surface attached flexible circuit board antenna, which comprises a circuit board body and a micropore array, the circuit board body comprises a deformation area and a fixed area, the micropore array is arranged in the deformation area, and the micropore array comprises a plurality of through holes distributed in an array; the circuit board body comprises an insulation surface layer, an insulation grid layer, a conductive circuit layer, a compensation circuit layer and an insulation bottom layer which are stacked in sequence, the conductive circuit layer comprises a radiation circuit and a welding terminal, the line width of the radiation circuit is larger than the aperture of the through hole, the radiation circuit is arranged in the deformation area, and the welding terminal is arranged in the fixing area. The compensation line layer comprises a plurality of compensation radiation rings connected with the radiation line, and the compensation radiation rings surround the periphery of the through hole. According to the utility model, the elastic modulus of a deformation area can be effectively reduced, the stress during bending is released, the stress concentration is avoided, the curved surface attachment effect is stable and reliable, the signal transmission reliability is high, and the structural stability is strong.

Description

A flexible circuit board antenna with curved surface attachment Technical Field

[0001] This utility model relates to the field of circuit board antennas, and in particular to a flexible circuit board antenna with curved surface attachment. Background Technology

[0002] Flexible printed circuit boards (FPCs) are a type of antenna made using flexible substrates. They are characterized by being thin, light, bendable, and easy to integrate. The demand for FPC antennas is growing in wearable devices, smart terminals, and automotive electronics.

[0003] The application environment of flexible circuit board antennas is often limited and complex. When flexible circuit board antennas are attached to curved surfaces, they are prone to springback, which can lead to impedance changes and breakage of the radiation circuits, affecting the reliability of signal transmission. Existing antennas have insufficient structural stability and are prone to signal distortion. Summary of the Invention

[0004] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention proposes a flexible circuit board antenna with curved surface attachment, which can adapt to the attachment of curved targets, has uniform stress distribution, stable and reliable structure, and high signal transmission reliability.

[0005] A flexible circuit board antenna with curved surface attachment according to an embodiment of the present utility model includes a circuit board body and a micro-hole array. The circuit board body includes a deformation region and a fixed region. The micro-hole array is disposed in the deformation region and includes a plurality of through holes arranged in an array and penetrating the circuit board body.

[0006] The circuit board body includes an insulating surface layer, an insulating mesh layer, a conductive line layer, a compensation line layer, and an insulating bottom layer stacked in sequence. The conductive line layer includes radiating lines and solder terminals. The line width of the radiating lines is larger than the diameter of the through holes. The radiating lines are located in the deformation area, and the solder terminals are located in the fixed area. The solder terminals are connected to the ends of the radiating lines. The compensation line layer includes several compensation radiating rings that connect the radiating lines. Each compensation radiating ring surrounds the corresponding through hole.

[0007] In this embodiment, the inner ring wall of each compensation radiation ring is covered with an insulating coating layer, and the insulating coating layer is also attached to the wall of the through hole communicating with the compensation radiation ring.

[0008] In this embodiment, the through hole is a regular hexagon.

[0009] In this embodiment, the ratio of the linewidth of the radiating line to the aperture of the through hole is 2 to 6.

[0010] In this embodiment, the center-to-center distance between any two adjacent through holes is 100–300 μm, and the diameter of the through holes is 20–50 μm.

[0011] In this embodiment, the width of the compensation radiation ring is 15–35 μm.

[0012] In this embodiment, the compensation radiation ring is a silver ring structure.

[0013] In this embodiment, the mesh of the insulating mesh layer is diamond-shaped.

[0014] The embodiments of this utility model have at least the following beneficial effects:

[0015] By dividing the circuit board body into a deformation area and a fixed area, the deformation area is used to attach to curved targets. The micro-hole array can effectively reduce the elastic modulus of the deformation area and improve its flexibility. Through holes penetrating the circuit board body can effectively release the stress generated by each layer of the structure during bending, avoiding stress concentration that could cause springback or damage to the circuit structure. This flexible circuit board antenna can effectively adapt to curved targets for attachment, and the curved surface attachment effect is stable and reliable. The through holes are located in the fixed area, avoiding the welding terminals, which can ensure that the fixed area is a complete substrate structure, effectively improving the stability of the welding structure between the welding terminals and external wires during application, and ensuring high signal transmission reliability. By setting a compensation radiation ring around the through hole on one side of the radiation line, the radiation area lost due to the opening of the radiation line can be effectively compensated, effectively ensuring the overall radiation efficiency of the antenna. While improving flexibility, it can effectively guarantee radiation performance, strong signal transmission fidelity, and strong structural stability. Moreover, the compensation radiation ring is only set for the radiation line, which can effectively improve the effectiveness of the compensation radiation ring, thereby effectively improving the cost investment. Attached Figure Description

[0016] The above and / or additional aspects and advantages of this utility model will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0017] Figure 1 is a three-dimensional structural diagram of the flexible circuit board antenna with curved surface attachment according to an embodiment of the present invention;

[0018] Figure 2 is an exploded structural diagram of the flexible circuit board antenna with curved surface attachment according to an embodiment of the present invention;

[0019] Figure 3 is a top view of the flexible circuit board antenna with curved surface attachment according to an embodiment of the present invention.

[0020] Figure 4 is a schematic diagram of the cross-sectional structure along A-A' in Figure 3;

[0021] Figure 5 is a magnified schematic diagram of structure B in Figure 4.

[0022] Figure label:

[0023] Circuit board body 100, deformation area 101, fixed area 102, insulating surface layer 110, insulating mesh layer 120, conductive line layer 130, radiating line 131, solder terminal 132, compensation line layer 140, compensation radiation ring 141, insulating coating layer 142, insulating bottom layer 150.

[0024] Micropore array 200, through hole 210. Detailed Implementation

[0025] The embodiments of this utility model are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0026] In the description of this utility model, it should be understood that the orientation descriptions, such as up, down, left, right, front, and back, are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0027] In the description of this utility model, if the wire sleeve or bracket is mentioned, it is only for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated or the order of the technical features indicated.

[0028] In the description of this utility model, unless otherwise explicitly defined, terms such as "setting," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this utility model in conjunction with the specific content of the technical solution.

[0029] Flexible circuit board antennas are antennas made using flexible substrates, characterized by their thinness, flexibility, and ease of integration. The demand for flexible circuit board antennas is growing in wearable devices, smart terminals, and automotive electronics. However, the application environments for flexible circuit board antennas are often spatially limited and complex. When attached to curved surfaces, uneven stress distribution in different areas can cause springback, leading to impedance abrupt changes and potential breakage of the radiation circuitry, affecting signal transmission reliability. Existing antennas suffer from insufficient structural stability, signal transmission distortion, and loosening or breakage of solder joints during bending, further compromising application reliability.

[0030] Referring to Figures 1 to 5, the following describes a flexible circuit board antenna with curved surface attachment according to an embodiment of the present invention. It can adapt to the attachment of curved targets, has uniform stress distribution, stable and reliable structure, and high reliability of signal transmission.

[0031] Referring to Figures 1 to 5, an embodiment of the present invention provides a flexible circuit board antenna with curved surface attachment, comprising a circuit board body 100 and a micro-hole array 200. Projected along a surface perpendicular to the circuit board body 100, the circuit board body 100 includes adjacent deformable regions 101 and fixed regions 102. The deformable regions 101 are used to adapt to the curved surface target, and the fixed regions 102 are used to provide a stable structural foundation for welding the conductive structure to ensure the reliability of the antenna. The micro-hole array 200 is disposed in the deformable regions 101 and includes a plurality of through holes 210 arranged in an array and penetrating the circuit board body 100. Each through hole 210 is disposed in the deformable regions 101 and avoids the fixed regions 102, thus avoiding damage to the fixed regions 102 and maintaining the fixed structural state of the circuit board body 100. The micro-hole array 200 performs drilling in an array batch manner, which has high processing efficiency. Specifically, drilling can be achieved by laser.

[0032] The circuit board body 100 includes, in sequence, an insulating surface layer 110, an insulating mesh layer 120, a conductive circuit layer 130, a compensating circuit layer 140, and an insulating bottom layer 150. The insulating bottom layer 150 and the insulating surface layer 110 can be configured in thickness as needed. The insulating mesh layer 120 and the compensating circuit layer 140 reinforce the structure from opposite sides of the conductive circuit layer 130, improving the stress balance of the conductive circuit layer 130. Preferably, adjacent layers are connected by an adhesive, typically applied to the bottom surface of the insulating surface layer 110 and the top surface of the insulating bottom layer 150. The circuit layer 130 includes radiating lines 131 and solder terminals 132. The radiating lines 131 are used to transmit or receive electromagnetic signals, and the solder terminals 132 are used to connect to the feed line. The linewidth of the radiating lines 131 is larger than the aperture of the through-hole 210. The aperture refers to the diameter of the fitted circle of the through-hole 210, which prevents the through-hole 210 from cutting off the radiating lines 131 and affecting their normal operation. The radiating lines 131 are located in the deformation region 101, and the solder terminals 132 are located in the fixed region 102. The micro-hole array 200 is positioned away from the solder terminals 132 to ensure that the performance of the solder terminals 132 is not affected. Terminal 132 can be a power supply terminal. The solder terminal 132 is connected to the end of the radiating line 131. The compensation line layer 140 includes a plurality of compensation radiation rings 141 connected to the side of the radiating line 131 near the insulating substrate 150. The compensation radiation rings 141 are disposed away from the solder terminal 132 and avoid the empty area of ​​the conductive line layer 130, which can effectively save the material cost of the compensation radiation rings 141 and avoid ineffective compensation radiation rings 141. The conductive line layer 130 is covered and protected by a mask structure with openings corresponding to the compensation radiation rings 141, and then protected by electroplating or chemical plating. Efficient processing is achieved through various methods to obtain the compensation radiation ring 141. The distribution pattern of the compensation radiation ring 141 connected to the surface of the radiation line 131 matches the distribution pattern of the through holes 210 penetrating the radiation line 131. Each compensation radiation ring 141 surrounds the corresponding through hole 210, that is, the central hole of each compensation radiation ring 141 is connected to the corresponding through hole 210. By connecting the compensation radiation ring 141 to the area where the through holes 210 are opened in the radiation line 131, a compensation radiation structure can be provided for the radiation line 131 that has been hollowed out due to the through holes 210, thereby effectively ensuring the radiation performance.

[0033] By dividing the circuit board body 100 into a deformation region 101 and a fixed region 102, the deformation region 101 is used for attachment to curved targets. The micro-hole array 200 can effectively reduce the elastic modulus of the deformation region 101 and improve its flexibility. The through-hole 210 penetrating the circuit board body 100 can effectively release the stress generated by each layer of the structure during bending, avoiding stress concentration that could cause springback or damage to the circuit structure. This flexible circuit board antenna can effectively adapt to curved targets for attachment, and the curved surface attachment effect is stable and reliable. The through-hole 210 avoids the soldering terminal 132 and is located in the fixed region 102, ensuring that the fixed region 102 is a complete substrate structure, which can effectively improve the contact between the soldering terminal 132 and the outside environment during application. The stability of the welded structure between the conductors ensures high reliability of signal transmission. By setting a compensation radiation ring 141 around the through hole 210 on one side of the radiation line 131, the radiation area lost by the radiation line 131 due to the opening can be effectively compensated, the impedance change can be effectively reduced, and the overall radiation efficiency of the antenna can be effectively ensured. While improving flexibility, the radiation performance can be effectively guaranteed. The signal transmission fidelity of this flexible circuit board antenna is strong, the structural stability is strong, and the compensation radiation ring 141 is only set for the radiation line 131, which can effectively improve the effectiveness of the compensation radiation ring 141, thereby effectively improving the effectiveness of cost investment and avoiding the compensation radiation ring 141 being distributed throughout the deformation area 101, which can reduce manufacturing costs.

[0034] It is understood that the inner ring wall of each compensation radiation ring 141, i.e. the central hole wall, is covered with an insulating coating layer 142. The insulating coating layer 142 is also attached to the hole wall of the through hole 210 that communicates with the compensation radiation ring 141. The insulating coating layer 142 can effectively provide insulation protection for the compensation radiation ring 141 and the radiation line 131, effectively reduce the corrosive effects of moisture and other substances in the environment, and effectively prevent edge creepage, thus effectively ensuring signal radiation performance.

[0035] The insulating coating layer 142 can be a layer structure made of modified polyimide coating mixed with nano-silica. During the manufacturing process, plasma cleaning and activation are used to clean and activate the inner wall of the through hole 210 and the inner wall of the compensation radiation ring 141. Then, the modified polyimide coating mixed with nano-silica particles is sprayed using nano-atomization spraying technology to form a uniform insulating coating layer 142 on the inner wall of the compensation radiation ring 141 and the inner wall of the through hole 210.

[0036] It is understandable that the through hole 210 is a regular hexagon. By setting the regular hexagonal honeycomb structure, a regional stress relief effect can be formed, and the bending direction of each through hole 210 can be effectively aligned, thereby improving the overall stress relief effect.

[0037] The hexagonal structure, through the uniform stress distribution along its six boundaries, decomposes localized concentrated stress into dispersed loads in six directions. Furthermore, the honeycomb arrangement automatically aligns the bending directions of adjacent through-holes 210 along their shared boundaries, forming a unified deformation coordination network. Compared to a circle, this provides a more stable stress release effect, and the crack propagation rate at the edge of the hexagonal through-hole 210 is significantly lower than that of a circular through-hole 210. Depending on the application, the through-hole 210 can also be configured as a circular hole.

[0038] Understandably, the ratio of the linewidth of the radiating line 131 to the aperture of the through hole 210 is 2 to 6. This prevents the through hole 210 from completely severing the radiating line 131, ensuring its normal operation and effectively improving its performance. It also effectively guarantees the conductive cross-sectional area, thereby improving the uniformity of the transmitted current density distribution and ensuring the reliability of signal transmission. Preferably, the ratio of the linewidth of the radiating line 131 to the aperture of the through hole 210 is 4, which significantly reduces the increase in resistance.

[0039] It is understandable that the center-to-center distance between any two adjacent through holes 210 is 100–300 μm, and the diameter of the through hole 210 is 20–50 μm. The center-to-center distance refers to the distance between the center points of the through holes 210. When the through hole 210 is a circular hole, the diameter refers to the diameter of the circular hole. When the through hole 210 is a regular hexagon, the diameter refers to the diameter of the circumcircle corresponding to the regular hexagon.

[0040] Preferably, the center-to-center distance between any two adjacent through holes 210 is set to 180 μm and the diameter of the through hole 210 is set to 30 μm, which can effectively improve the stress release effect. The width of the solid material between any two adjacent through holes 210 is 150 μm, which can effectively ensure the tensile strength of this flexible circuit board antenna.

[0041] It is understandable that the compensation radiation ring 141 is a circular ring with a width of 15-35 μm, which can effectively ensure the compensation effect of electromagnetic radiation and restore the radiation efficiency to more than 95% of the holeless design.

[0042] It is understandable that the compensation radiation ring 141 is a silver ring structure. Silver rings have better conductivity than ordinary copper circuit structures. Under the same volume, the conductivity of silver is greater than that of copper.

[0043] Compared to using copper, using silver to make the compensation radiation ring 141 is a silver ring structure, which can effectively reduce the thickness of the compensation radiation ring 141, thus effectively adapting to curved surface attachment applications. In addition, silver has good ductility, which can further ensure the bendability of this flexible circuit board antenna and better adapt to curved surface attachment applications.

[0044] It is understood that the insulating mesh layer 120 has a rhomboid mesh. This rhomboid mesh effectively improves flexibility while maintaining vertical support strength. The acute angle of the insulating mesh is 45°–65°, ensuring isotropic mechanical properties. Preferably, the mesh of the insulating mesh layer is aligned and connected to the through-hole 210.

[0045] Although embodiments of the present invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A flexible circuit board antenna with curved surface attachment, characterized in that, The circuit board includes a circuit board body (100) and a microvia array (200). The circuit board body (100) includes a deformation region (101) and a fixed region (102). The microvia array (200) is disposed in the deformation region (101) and includes a plurality of through holes (210) arranged in an array and penetrating the circuit board body (100). The circuit board body (100) includes an insulating surface layer (110), an insulating mesh layer (120), a conductive circuit layer (130), a compensation circuit layer (140), and an insulating bottom layer (150) stacked sequentially. 0) includes a radiating line (131) and a welding terminal (132). The line width of the radiating line (131) is larger than the aperture of the through hole (210). The radiating line (131) is located in the deformation region (101). The welding terminal (132) is located in the fixed region (102). The welding terminal (132) is connected to the end of the radiating line (131). The compensation line layer (140) includes a plurality of compensation radiation rings (141) connected to the radiating line (131). Each compensation radiation ring (141) surrounds the corresponding through hole (210).

2. The flexible circuit board antenna with curved surface attachment according to claim 1, characterized in that, The inner ring wall of each of the compensation radiation rings (141) is covered with an insulating coating layer (142), and the insulating coating layer (142) is also attached to the wall of the through hole (210) communicating with the compensation radiation ring (141).

3. The flexible circuit board antenna with curved surface attachment according to claim 1, characterized in that, The through hole (210) is a regular hexagon.

4. The flexible circuit board antenna with curved surface attachment according to claim 1, characterized in that, The ratio of the linewidth of the radiating line (131) to the aperture of the through hole (210) is 2 to 6.

5. The flexible circuit board antenna with curved surface attachment according to claim 1, characterized in that, The center-to-center distance between any two adjacent through holes (210) is 100 to 300 μm, and the diameter of the through hole (210) is 20 to 50 μm.

6. The flexible circuit board antenna with curved surface attachment according to claim 5, characterized in that, The width of the compensation radiation ring (141) is 15–35 μm.

7. The flexible circuit board antenna with curved surface attachment according to claim 1, characterized in that, The compensation radiation ring (141) has a silver ring structure.

8. The flexible circuit board antenna with curved surface attachment according to claim 1, characterized in that, The mesh of the insulating mesh layer (120) is diamond-shaped.

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