Anti-warping multilayer FPC antenna

Abstract

The utility model discloses an anti-warping multilayer FPC antenna, comprising an FPC body comprising a first protection layer, a radiation line layer, a flexible substrate, a grounding layer, an insulation layer and a second protection layer which are stacked in sequence, the radiation line layer comprises a main radiation body and a branch radiation body which are connected, and the grounding layer is provided with an abdicating gap; the micro-strip feeder line is arranged between the insulating layer and the second protective layer, one end of the micro-strip feeder line directly faces the main radiator and is arranged in the abdicating gap, and a feed connection structure is arranged between one end of the micro-strip feeder line and the main radiator; the stress adjusting structure comprises a plurality of reinforcing ribs and a plurality of round holes penetrating through the FPC body, all the reinforcing ribs are distributed on one side of the second protection layer at equal intervals, and intervals are formed between the round holes and the main radiator, between the round holes and the branch radiators and between the round holes and the microstrip feeder. The cable is wide in area and application range, can reduce the stress formed during bending, is good in anti-warping performance, and is reliable in signal transmission.

Description

Technical Field

[0001] This utility model relates to the field of FPC antennas, and in particular to an anti-warping multilayer FPC antenna. Background Technology

[0002] FPC (Flexible Printed Circuit) antennas are antennas made using flexible substrates. They are characterized by being thin, light, bendable, and easy to integrate, and are widely used in the Internet of Things, mobile devices, wearable devices, and other fields.

[0003] An FPC antenna mainly consists of a substrate and radiating circuitry disposed on the surface of the substrate. The surface of the radiating circuitry is also covered with a protective layer. The radiating circuitry structure is used to convert electrical signals into electromagnetic signals. Depending on different application requirements, the radiating circuitry of the FPC antenna needs to be set with different shapes and sizes, requiring a large substrate area to realize the design of the radiating circuitry. In the existing technology, FPC antennas have a large area, which limits the application scenarios. Moreover, large-area FPC antennas often generate large stresses when bent, making them prone to warping or even breakage. Utility Model Content

[0004] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention proposes an anti-warping multilayer FPC antenna with a small area, which can effectively disperse stress when bending occurs, exhibits good anti-warping performance, and has a wide range of applications.

[0005] An anti-warping multilayer FPC antenna according to an embodiment of the present invention includes:

[0006] The FPC body includes a first protective layer, a radiating circuit layer, a flexible substrate, a grounding layer, an insulating layer, and a second protective layer stacked in sequence. The radiating circuit layer includes a main radiator and branch radiators connected together, and the grounding layer is provided with a clearance gap.

[0007] A microstrip feeder is located between the insulating layer and the second protective layer. One end of the microstrip feeder faces the main radiator and is located in the clearance gap. A power supply connection structure is provided between one end of the microstrip feeder and the main radiator. The power supply connection structure is used to transmit the signal between the microstrip feeder and the main radiator.

[0008] The stress adjustment structure includes several reinforcing ribs and several circular holes penetrating the FPC body. All the reinforcing ribs are evenly distributed on the side of the second protective layer away from the insulating layer. The circular holes are spaced apart from the main radiator, the branch radiator and the microstrip feeder, respectively.

[0009] In this embodiment, the power supply connection structure is a slot coupling, and the width of the slot coupling is 0.1 to 0.3 mm.

[0010] In this embodiment, the clearance gap is H-shaped, and one end of the microstrip feeder is located at the center of the clearance gap.

[0011] In this embodiment, the power supply connection structure is a power supply post, which is inserted through the flexible substrate.

[0012] In this embodiment, a power supply terminal is provided at the other end of the microstrip feed line, a grounding terminal is provided at the edge of the grounding layer, an epitaxial substrate is provided between the power supply terminal and the grounding terminal, and the epitaxial substrate is connected to the edge of the insulating layer.

[0013] In this embodiment, the radiating line layer, the ground layer, and the microstrip feeder are all rolled copper conductive structures.

[0014] In this embodiment, the flexible substrate is a liquid crystal polymer substrate or a modified polyimide substrate.

[0015] In this embodiment, both the first protective layer and the second protective layer are PI-fluorinated siloxane composite layers.

[0016] In this embodiment, all the reinforcing ribs surround the edge of the second protective layer.

[0017] The embodiments of this utility model have at least the following beneficial effects:

[0018] By layering the radiating circuit layer, ground layer, and microstrip feeder, different circuit structures are located in different dimensions, effectively reducing the area occupied in a single dimension. This effectively controls the area of ​​the FPC antenna, broadening its application range and reducing stress during bending, resulting in good anti-warping performance. The composite surface structure formed by equally spaced reinforcing ribs and a second protective layer maintains flexibility while limiting the critical bending amplitude, effectively reducing interlayer shear stress. The circular holes penetrating the FPC body disperse bending stress in all directions, preventing stress concentration and damage to the circuit structure, thus providing good anti-warping performance. Furthermore, the circular holes are spaced apart from the radiator and microstrip feeder, effectively reducing the probability of large-scale strain in the circuit structure during stress release, effectively improving the structural integrity of this multi-layer FPC antenna under dynamic bending, resulting in a stable and reliable overall structure. The ground layer forms an electromagnetic shielding structure on the back of the radiating circuit layer, and the clearance gaps allow for the connection between the microstrip feeder and the power supply structure, effectively improving the reliability of signal transmission. Attached Figure Description

[0019] 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:

[0020] Figure 1 This is a top view of the anti-warping multilayer FPC antenna according to an embodiment of the present invention.

[0021] Figure 2 This is a bottom view of the anti-warping multilayer FPC antenna according to an embodiment of the present invention.

[0022] Figure 3 This is a cross-sectional view of the anti-warping multilayer FPC antenna according to an embodiment of the present invention.

[0023] Figure 4 This is a schematic diagram of the structure of the layer containing the radiating circuit layer in the anti-warping multilayer FPC antenna according to an embodiment of the present invention.

[0024] Figure 5 This is a schematic diagram of the structure of the layer containing the flexible substrate in the anti-warping multilayer FPC antenna according to an embodiment of the present invention.

[0025] Figure 6 This is a schematic diagram of the structure of the ground layer in the anti-warping multilayer FPC antenna according to an embodiment of the present invention.

[0026] Figure 7 This is a schematic diagram of the structure of the layer containing the microstrip feed line in the anti-warping multilayer FPC antenna of this utility model embodiment.

[0027] Figure label:

[0028] FPC body 100, first protective layer 110, radiating line layer 120, main radiator 121, branch radiator 122, flexible substrate 130, grounding layer 140, clearance gap 141, insulating layer 150, second protective layer 160.

[0029] Microstrip feeder 200, power supply connection structure 210;

[0030] Stress adjustment structure 300, reinforcing rib 310, round hole 320;

[0031] Power supply terminal 400, grounding terminal 410, epitaxial substrate 420. Detailed Implementation

[0032] 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.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] FPC (Flexible Printed Circuit) antennas are antennas made using flexible substrates. They are characterized by their thinness, flexibility, and ease of integration, and are widely used in the Internet of Things (IoT), mobile devices, and wearable devices. An FPC antenna mainly consists of a substrate and radiating circuitry on the substrate surface. The surface of the radiating circuitry is also covered with a protective layer. The radiating circuitry structure is used to convert electrical signals into electromagnetic signals. Depending on the application requirements, the radiating circuitry of an FPC antenna needs to be set in different shapes and sizes, requiring a large substrate area to implement the radiating circuitry design. Current FPC antennas have a large area, limiting their application scenarios. Furthermore, large-area FPC antennas often experience significant stress when bent, making them prone to warping or even breakage.

[0037] The following is for reference only. Figure 1 To be continued Figure 7 This invention describes an anti-warping multilayer FPC antenna with a small area, which can effectively disperse stress when bending, has good anti-warping performance, and has a wide range of applications.

[0038] Reference Figures 1 to 7 An anti-warping multilayer FPC antenna according to an embodiment of the present invention includes:

[0039] The FPC body 100 includes a first protective layer 110, a radiating circuit layer 120, a flexible substrate 130, a grounding layer 140, an insulating layer 150, and a second protective layer 160 stacked sequentially. Each pair of adjacent layers is connected by adhesive bonding. The radiating circuit layer 120 includes a connected main radiator 121 and a branch radiator 122. The grounding layer 140 is provided with a clearance gap 141 and is used to connect a ground wire. The main radiator 121 and the branch radiator 122 are used to realize signal radiation of different frequencies.

[0040] The microstrip feed line 200, located between the insulating layer 150 and the second protective layer 160, also provides good shielding protection through the large-area structure of the grounding layer 140, effectively reducing signal interference to the radiating line layer 120 and thus improving signal transmission reliability. The end of the microstrip feed line 200 closest to the radiating line layer 120 faces the main radiator 121 and is located in the clearance gap 141; that is, the end of the microstrip feed line 200 closest to the radiating line layer 120 is the microstrip feed node. The microstrip feed node passes through the insulating layer 150 and is located in the clearance gap 141, with the microstrip feed node facing the main radiator 121. The microstrip feed line 200 is isolated from the ground layer 140 by the clearance gap 141. A feed connection structure 210 is provided between the end of the microstrip feed line 200 near the radiating line layer 120 and the main radiator 121. That is, the microstrip feed node and the main radiator 121 are connected by the feed connection structure 210. The feed connection structure 210 can be a non-contact slot coupling or a contact feed post. The feed connection structure 210 is formed on the flexible substrate 130, so that the feed connection structure 210 is used to transmit the signal between the microstrip feed line 200 and the main radiator 121. The other end of the microstrip feed line 200 is used to connect the signal processing circuit.

[0041] The stress adjustment structure 300 includes several reinforcing ribs 310 and several circular holes 320 penetrating the FPC body 100. All the reinforcing ribs 310 are distributed at equal intervals on the side of the second protective layer 160 away from the insulating layer 150. The reinforcing ribs 310 can effectively limit the bending amplitude of the multilayer FPC antenna, thereby effectively improving the anti-warping performance. The circular holes 320 are separated from the main radiator 121, the branch radiator 122 and the microstrip feed line 200, respectively. That is, the circular holes 320 are separated from the main radiator 121, the branch radiator 122 and the microstrip feed line 200. This can effectively prevent the stress released in the circular holes 320 during bending from affecting the radiator structure and the microstrip feed line 200, thereby effectively improving the stability of the overall structure. This multilayer FPC antenna has good anti-warping performance. The position of the circular holes 320 is set according to the actual application requirements. The circular holes 320 can be set in areas prone to bending.

[0042] By layering the radiating line layer 120, ground layer 140, and microstrip feed line 200, different line structures are located in different dimensions, effectively reducing the area occupied in a single dimension and thus effectively controlling the area of ​​the FPC antenna. This results in a wide range of applications and reduces stress during bending, providing good anti-warping performance. The equally spaced reinforcing ribs 310, combined with the second protective layer 160, form a composite surface structure that maintains flexibility while limiting the critical bending amplitude, effectively reducing interlayer shear stress and thus reducing the warping of this multi-layer FPC. This results in high structural stability. The circular holes 320 penetrating the FPC body 100 disperse bending stress in all directions, preventing stress concentration and damage to the line structure, thus providing good anti-warping performance. Furthermore, the circular holes 320 are respectively connected to the radiator and the microstrip feed line. The 200-space interval effectively reduces the probability of large-scale strain in the circuit structure during stress release, effectively improving the structural integrity of this multi-layer FPC antenna under dynamic bending, ensuring overall structural stability and reliability, and maintaining the functional reliability of the antenna structure. The grounding layer 140 forms an electromagnetic shielding structure on the back of the radiating circuit layer 120, and the clearance gap 141 provides clearance between the microstrip feed line 200 and the feed connection structure 210. This not only ensures isolation between the microstrip feed line 200 and the grounding layer 140, but also, in conjunction with the design of the feed connection structure 210 embedded in the flexible substrate 130, reduces the direct stress on the feed connection structure 210, improves impedance matching stability, effectively reduces VSWR fluctuations, and effectively improves signal transmission reliability.

[0043] It is understood that the power supply connection structure 210 is a slot coupling, and the slot width of the slot coupling is 0.1 to 0.3 mm, specifically 0.15 mm.

[0044] Slot coupling, also known as non-contact slot coupling, enables signal transmission between the microstrip feed line 200 and the main radiator 121 using an electric or magnetic field. The non-contact structure effectively avoids the stress effects caused by warping, thus improving the reliability of signal transmission between the microstrip feed line 200 and the main radiator 121. This effectively improves the anti-warping performance of the multilayer FPC antenna. Furthermore, slot coupling effectively reduces solder joint losses, further enhancing the reliability of signal transmission.

[0045] It is understandable that the projection shape of the clearance gap 141 along the direction perpendicular to the FPC body 100 is H-shaped, that is, I-shaped. The end of the microstrip feed line 200 near the radiating line layer 120 is located at the center of the clearance gap 141. The two ends of the horizontal slot at the center of the clearance gap 141 are connected to two vertical slots respectively. The microstrip feed line 200 is parallel to the horizontal slot, and the end of each vertical slot extends to the edge of the ground layer 140.

[0046] The horizontal slot is used to generate strong electric field coupling, and the vertical slot is used to guide the magnetic field distribution. This can effectively improve the transmission effect of slot coupling signals. In addition, the vertical slot can also block the lateral propagation of current on the surface of the grounding layer 140, which can reduce edge radiation and thus improve the stability of the radiation pattern.

[0047] It is understandable that the power supply connection structure 210 is a power supply post, which is inserted through the flexible substrate 130. The two ends of the power supply post are respectively connected to the end of the microstrip feed line 200 away from the radiation line layer and the main radiator 121. The power supply connection between the microstrip feed line 200 and the main radiator 121 is realized through a contact structure, which is convenient to process and has a simple structure.

[0048] It should be noted that a grounding post passing through the flexible substrate 130 can be connected between the main radiator 121 and the grounding layer 140. The grounding post connects the main radiator 121 and the grounding layer 140, which can achieve potential balance.

[0049] It is understood that the other end of the microstrip feed line 200 is provided with a feed terminal 400, that is, the end of the microstrip feed line 200 away from the radiating line layer 120 is provided with a feed terminal 400, and a ground terminal 410 is provided at the edge of the ground layer 140, directly opposite the feed terminal 400. An epitaxial substrate 420 is provided between the feed terminal 400 and the ground terminal 410, and the epitaxial substrate 420 is connected to the edge of the insulating layer 150. Both the feed terminal 400 and the ground terminal 410 have protective layers on their surfaces, and each protective layer has a corresponding window to allow space for the feed terminal 400 and the ground terminal 410.

[0050] The epitaxial substrate 420 is used to provide an attachment base for the feed terminal 400 and the ground terminal 410, and to achieve isolation between the feed terminal 400 and the ground terminal 410. The feed terminal 400 is used to connect the signal terminal of the signal processing circuit, and the ground terminal 410 is used to connect the ground terminal of the signal processing circuit. The feed terminal 400, the epitaxial substrate 420 and the ground terminal 410 are all located outside the FPC body 100, making the conductive connection between the signal processing circuit and the multilayer FPC antenna convenient.

[0051] It is understandable that the radiating line layer 120, the ground layer 140, and the microstrip feed line 200 are all rolled copper conductive structures. That is, the radiating line layer 120, the ground layer 140, and the microstrip feed line 200 are all made of rolled copper foil with corresponding line shapes. Rolled copper is a product made by repeatedly rolling and annealing high-precision copper strips using the principle of plastic processing. It has good ductility, bending resistance, and conductivity, which can effectively and comprehensively improve the anti-warping performance of this multi-layer FPC antenna.

[0052] It is understandable that the flexible substrate 130 is a liquid crystal polymer substrate or a modified polyimide substrate, wherein the insulating layer 150 is a liquid crystal polymer layer or a modified polyimide layer, which can effectively reduce dielectric loss.

[0053] It is understood that both the first protective layer 110 and the second protective layer 160 are PI-fluorinated siloxane composite layers. PI refers to polyimide, and the PI-fluorinated siloxane composite layer refers to a polyimide film layer with fluorinated siloxane covering its surface, which can effectively improve the drop resistance of this multilayer FPC antenna.

[0054] Understandably, all the reinforcing ribs 310 are arranged in a frame around the edge of the second protective layer 160. The reinforcing ribs 310 can effectively improve the structural stability of the multi-layer FPC antenna. When the reinforcing ribs 310 are installed in the frame of the target product, they can also form a certain support and buffer effect, thereby effectively improving the structural stability during installation and application, and reducing the impact of the multi-layer FPC antenna on problems such as collisions and drops during application.

[0055] 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 warp-resistant multilayer FPC antenna, characterized in that, include: The FPC body (100) includes a first protective layer (110), a radiating circuit layer (120), a flexible substrate (130), a grounding layer (140), an insulating layer (150), and a second protective layer (160) stacked in sequence. The radiating circuit layer (120) includes a main radiator (121) and a branch radiator (122) connected together. The grounding layer (140) is provided with a clearance gap (141). A microstrip feed line (200) is disposed between the insulating layer (150) and the second protective layer (160). One end of the microstrip feed line (200) faces the main radiator (121) and is disposed in the clearance gap (141). A power supply connection structure (210) is provided between one end of the microstrip feed line (200) and the main radiator (121). The power supply connection structure (210) is used to transmit the signal between the microstrip feed line (200) and the main radiator (121). The stress adjustment structure (300) includes a plurality of reinforcing ribs (310) and a plurality of circular holes (320) penetrating the FPC body (100). All the reinforcing ribs (310) are equally spaced on the side of the second protective layer (160) away from the insulating layer (150). The circular holes (320) are spaced apart from the main radiator (121), the branch radiator (122) and the microstrip feed line (200).

2. The anti-warping multilayer FPC antenna according to claim 1, characterized in that, The power supply connection structure (210) is a slot coupling, and the width of the slot coupling is 0.1 to 0.3 mm.

3. The anti-warping multilayer FPC antenna according to claim 2, characterized in that, The clearance gap (141) is H-shaped, and one end of the microstrip feed line (200) is located at the center of the clearance gap (141).

4. The anti-warping multilayer FPC antenna according to claim 1, characterized in that, The power supply connection structure (210) is a power supply post, which is inserted through the flexible substrate (130).

5. The anti-warping multilayer FPC antenna according to claim 1, characterized in that, The other end of the microstrip feed line (200) is provided with a power supply terminal (400), and the edge of the ground layer (140) is provided with a ground terminal (410). An epitaxial substrate (420) is provided between the power supply terminal (400) and the ground terminal (410), and the epitaxial substrate (420) is connected to the edge of the insulating layer (150).

6. The anti-warping multilayer FPC antenna according to claim 1, characterized in that, The radiating line layer (120), the ground layer (140), and the microstrip feed line (200) are all rolled copper conductive structures.

7. The anti-warping multilayer FPC antenna according to claim 1, characterized in that, The flexible substrate (130) is a liquid crystal polymer substrate or a modified polyimide substrate.

8. The anti-warping multilayer FPC antenna according to claim 1, characterized in that, Both the first protective layer (110) and the second protective layer (160) are PI-fluorinated siloxane composite layers.

9. The anti-warping multilayer FPC antenna according to claim 1, characterized in that, All of the reinforcing ribs (310) surround the edge of the second protective layer (160).

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