A signal transmission structure

Abstract

The present invention provides a signal transmission structure, comprising a PI dielectric layer, a first copper foil layer and a second copper foil layer arranged on the upper and lower surfaces of the PI dielectric layer, wherein the first copper foil layer comprises a signal line area and two first grounding areas spaced apart from two side walls of the signal line area in the transverse direction, the second copper foil layer comprises a second grounding area arranged corresponding to the signal line area, a plurality of hollow grooves are spaced apart along the axial direction of the signal line area on the second grounding area, the orthographic projection of the groove wall of the hollow groove on the lower surface of the PI dielectric layer has two endpoints with the largest distance in the transverse direction, and the orthographic projection of the two side walls on the lower surface is located between the two endpoints, and the two first grounding areas are electrically connected to the second grounding area through a plurality of conductive members respectively arranged in the PI dielectric layer. The present invention solves the problem that the stretching rate of the signal transmission structure is relatively low and cannot meet the scalability requirements.

Description

Technical Field

[0001] The present invention relates to the technical field of circuit board manufacturing, and in particular to a signal transmission structure. Background Art

[0002] In recent years, with the rapid development of science and technology, electronic devices have been used more widely than ever before in smart wearables, implantable medical devices, biotechnology and many other emerging fields. These fields have put forward higher requirements on the form and function of electronic devices, especially in terms of improving user comfort. Flexible, scalable and conformable electronic devices have become a new development trend. However, traditional electronic device designs usually adopt rigid structures, which are difficult to meet the requirements of these emerging fields for device form flexibility and adaptability.

[0003] In order to overcome this problem, the industry has conducted a lot of research, trying to apply flexible materials and technologies to electronic devices, so that electronic devices can maintain their scalability while solving the problem of easy breakage of lines between interconnect structures of stretchable electronic devices. This has promoted the development of flexible electronic devices to a certain extent.

[0004] However, with the increasing diversification and miniaturization of electronic equipment functions, the single-layer or multi-layer flexible circuit board process has gradually shown its limitations. Most current designs only focus on the DC conduction interconnection between electronic components, but ignore the fact that in complex application scenarios, electronic devices also need to undertake multiple functions such as data processing, high-speed signal transmission, signal transmission and reception, etc. The stretchability of these signal transmission structures is usually low and cannot meet the scalability requirements.

[0005] Therefore, the development and manufacturing of flexible and stretchable signal transmission structures has become a technical bottleneck that needs to be solved urgently. Summary of the invention

[0006] The object of the present invention is to provide a signal transmission structure to solve the problem that the stretching rate of the signal transmission structure in the prior art is usually low and cannot meet the scalability requirement.

[0007] In order to achieve the above-mentioned purpose of the present invention, an embodiment of the present invention provides a signal transmission structure, which includes a PI dielectric layer, a first copper foil layer and a second copper foil layer arranged on the upper and lower surfaces of the PI dielectric layer, the first copper foil layer includes a signal line area and two first grounding areas spaced outside two side walls of the signal line area in the lateral direction, the second copper foil layer includes a second grounding area arranged corresponding to the signal line area, and a plurality of hollow grooves are evenly spaced on the second grounding area along the axial direction of the signal line area, the orthographic projection of the groove side wall of the hollow groove on the lower surface of the PI dielectric layer has two endpoints with the largest distance in the lateral direction, and the orthographic projection of the two side walls on the lower surface is located between the two endpoints, and the two first grounding areas are respectively electrically connected to the second grounding area through a plurality of conductive members penetrating the PI dielectric layer.

[0008] As a further improvement of an embodiment of the present invention, the hollow groove penetrates the second copper foil layer in a direction perpendicular to the second copper foil layer.

[0009] As a further improvement of one embodiment of the present invention, the signal transmission structure also includes an anti-oxidation layer, the anti-oxidation layer includes a glue layer and a PI layer, the glue layer covers the first copper foil layer and the second copper foil layer, and the PI layer is arranged on the glue layer.

[0010] As a further improvement of an embodiment of the present invention, the signal transmission structure further includes an elastic film layer, and the elastic film layer is respectively arranged on the PI layer on the first copper foil layer and the second copper foil layer.

[0011] As a further improvement of an embodiment of the present invention, the spacing between the signal line area and the two first grounding areas is not less than 35 um.

[0012] As a further improvement of an embodiment of the present invention, the distance between the two endpoints is 200um to 400um.

[0013] As a further improvement of an embodiment of the present invention, the spacing between any two adjacent hollow grooves is 50um to 150um.

[0014] As a further improvement of an embodiment of the present invention, the thickness of the PI dielectric layer is 15 to 50 um.

[0015] As a further improvement of an embodiment of the present invention, the signal line area follows a zigzag route, and the two first grounding areas and the second grounding area are both arranged to cooperate with the zigzag route of the signal line area, the two first grounding areas include a first side grounding area located on one side of the signal line area and a second side grounding area located on the other side, the first side grounding area includes a plurality of first curved sections protruding from the second side grounding area toward the first side grounding area, and the second side grounding area includes a plurality of second curved sections protruding from the first side grounding area toward the second side grounding area.

[0016] As a further improvement of one embodiment of the present invention, a first protrusion is formed on a side of the first curved section away from the signal line area and protrudes along the side away from the signal line area, and a second protrusion is formed on a side of the second curved section away from the signal line area and protrudes along the side away from the signal line area, and grounding holes are provided on the first protrusion and the second protrusion, one end of the conductive member is electrically connected to the grounding hole, and the other end is electrically connected to the second grounding area.

[0017] As a further improvement of an embodiment of the present invention, the signal transmission structure also includes two static connection areas arranged at both ends of the signal line area, the first grounding area and the second grounding area, and each static connection area is fixedly provided with an auxiliary signal line area, a first auxiliary grounding area and a second auxiliary grounding area, the auxiliary signal line area is connected to one end of the signal line area, the first auxiliary grounding area is connected to one end of the first grounding area, and one end of the second auxiliary grounding area is connected to one end of the second grounding area.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] By evenly spacing a plurality of hollow grooves, the orthographic projections of the groove sidewalls of the hollow grooves on the lower surface of the PI dielectric layer have two endpoints with the largest distance in the horizontal direction, and the orthographic projections of the two sidewalls on the lower surface are located between the two endpoints. On the one hand, the stretching rate of the signal transmission structure can be increased; on the other hand, the signal transmission loss can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A schematic diagram of a signal transmission structure provided by an embodiment of the present invention;

[0021] Figure 2 for Figure 1 A schematic diagram of the structure of the signal transmission structure after removing the elastic film layer;

[0022] Figure 3 for Figure 2 A top view of

[0023] Figure 4 for Figure 3 Schematic diagram of the cross-sectional structure in the AA direction;

[0024] Figure 5 for Figure 3 Schematic diagram of the cross-sectional structure in the middle BB direction;

[0025] Figure 6 for Figure 3 Schematic diagram of the local structure of the signal transmission structure after removing the anti-oxidation layer;

[0026] Figure 7 for Figure 6 Enlarged view of point M in the middle.

[0027] The above description of the drawings includes the following reference numerals:

[0028] 1. PI dielectric layer;

[0029] 2. The first copper foil layer;

[0030] 21. Signal line area;

[0031] 211, side wall;

[0032] 22. The first grounding area;

[0033] 221, first side grounding area;

[0034] 2211, first curved section;

[0035] 2212, first protrusion;

[0036] 222, second side grounding area;

[0037] 2221, second curved section;

[0038] 2222, second protrusion;

[0039] 3. The second copper foil layer;

[0040] 31. Second grounding area;

[0041] 32. Hollow slot;

[0042] 4. Conductive parts;

[0043] 5. Anti-oxidation layer;

[0044] 51. Adhesive layer;

[0045] 52. PI layer;

[0046] 6. Elastic film layer;

[0047] 7. Static connection area. DETAILED DESCRIPTION

[0048] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0049] It should be noted that, unless otherwise specified, all technical and scientific terms used in this application have the same meanings as commonly understood by ordinary technicians in the technical field to which this application belongs.

[0050] In the present invention, unless otherwise specified, the directional words used, such as "up, down, top, bottom", usually refer to the directions shown in the drawings, or to the components themselves in the vertical, perpendicular or gravity directions; similarly, for ease of understanding and description, "inside and outside" refer to the inside and outside relative to the outline of each component itself, but the above-mentioned directional words are not used to limit the present invention.

[0051] In order to solve the problem that the stretching rate of the signal transmission structure in the prior art is usually low and cannot meet the scalability requirement, the present invention provides a signal transmission structure.

[0052] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0053] like Figure 1-7 As shown, a signal transmission structure provided by the present invention comprises a PI dielectric layer 1, a first copper foil layer 2 and a second copper foil layer 3 arranged on the upper and lower surfaces of the PI dielectric layer 1, the first copper foil layer 2 comprises a signal line area 21 and two first grounding areas 22 spaced apart from two side walls 211 arranged in a lateral direction of the signal line area, the second copper foil layer 3 comprises a second grounding area 31, the second grounding area 31 is arranged corresponding to the signal line area 21, a plurality of hollow grooves 32 are evenly spaced apart along the axial direction of the signal line area 21 on the second grounding area 31, the orthographic projection of the groove side wall of the hollow groove 32 on the lower surface of the PI dielectric layer 1 has two end points with the largest distance in the lateral direction, and the orthographic projection of the two side walls 211 on the lower surface is located between the two end points, and the two first grounding areas 22 are electrically connected to the second grounding area 31 respectively through a plurality of conductive members 4 penetrating the PI dielectric layer 1.

[0054] By evenly spacing a plurality of hollow grooves 32, the orthographic projection of the groove wall of the hollow groove 32 on the lower surface of the PI dielectric layer 1 has two endpoints with the largest distance in the horizontal direction, and the orthographic projection of the two side walls 211 on the lower surface is located between the two endpoints. On the one hand, the stretching rate of the signal transmission structure can be increased; on the other hand, the signal transmission loss can be reduced.

[0055] In the present invention, the signal line area 21 is extended in the axial direction thereof, and the horizontal direction perpendicular to the axial direction is defined as the lateral direction in the present invention.

[0056] It should be noted that, through the arrangement of the hollow groove 32, the orthographic projection of the side wall of the hollow groove on the lower surface of the PI dielectric layer has two endpoints with the largest distance in the horizontal direction, and the orthographic projection of the two side walls 211 on the lower surface of the PI dielectric layer 1 is located between the two endpoints. Under the same impedance, for example, in this embodiment, under the condition of meeting the impedance of 50ohm, the width of the signal line area 21 (that is, the distance between the two side walls 211) can be relaxed to more than 60um or more, corresponding to Figure 4 As shown in , that is, the width of W can be relaxed to more than 60um or larger.

[0057] This arrangement reduces the precision requirements for processing equipment and is more conducive to improving the yield rate of the signal transmission structure. In the prior art, since the second grounding area 31 is not provided with a hollow groove 32, the width of the signal line area 21 needs to be set at about 45um when the impedance is 50ohm. Such a narrow line width has reached the limit of the flexible board process, which often leads to a significant reduction in the yield rate of the signal line area 21 and production defects.

[0058] In this embodiment, the signal line region 21 and the two first grounding regions 22 can be formed by etching the first copper foil layer 2 ; similarly, the second grounding region 31 and the hollow groove 32 can be formed by etching the second copper foil layer 3 .

[0059] It should be noted that, in the present invention, the hollow grooves 32 are distributed in the second grounding area 31 along the axial array, and the first copper foil layer 2 and the second copper foil layer 3 are arranged in parallel.

[0060] In this embodiment, preferably, the hollow groove 32 penetrates the second grounding area 31 in a direction perpendicular to the second copper foil layer 3, and the shape of the groove sidewall of the hollow groove 32 in the cross section parallel to the second copper foil layer 3 can be square, diamond, circular, etc. The present invention does not limit this. The designer can set it according to actual needs, and all schemes that adopt the same or similar schemes as this embodiment are covered within the protection scope of the present invention.

[0061] It should be emphasized that when the shape of the groove sidewall of the hollow groove 32 in the cross section parallel to the second copper foil layer 3 is a square or a rhombus. If one diagonal of the square or rhombus is parallel to the horizontal direction, then the two endpoints are the orthographic projections of the two vertices located at both ends of the aforementioned diagonal on the lower surface of the PI dielectric layer 1; if the diagonals of the square or rhombus intersect with the horizontal direction, then the square or rhombus must have two opposite sides arranged oppositely in the horizontal direction, one of the two endpoints is located on the orthographic projection of one of the two opposite sides arranged oppositely on the lower surface of the PI dielectric layer 1, and the other of the two endpoints is located on the orthographic projection of the other of the two opposite sides arranged oppositely on the lower surface of the PI dielectric layer 1.

[0062] In particular, when the groove side wall of the hollow groove 32 is circular in shape on the cross section parallel to the second copper foil layer 3 , the circle has a diameter parallel to the transverse direction, and the two endpoints are the orthographic projections of the two endpoints of the diameter on the lower surface of the PI dielectric layer 1 .

[0063] The signal transmission structure further includes an anti-oxidation layer 5, which is composed of a glue layer 51 and a PI layer 52. Specifically, the glue layer 51 directly covers the exposed surface of the first copper foil layer 2 and the second copper foil layer 3 to form a barrier that isolates oxygen. The glue layer 51 not only has good adhesion to ensure close fit with the copper foil layer, but also has a certain degree of flexibility to adapt to the expansion and contraction deformation of the signal transmission structure.

[0064] Accordingly, the PI layer 52 is provided on the adhesive layer 51 as an outer layer protection, and provides additional protection for the entire structure by using its excellent insulation and high temperature resistance. Such a design effectively avoids the oxidation problem of the signal line area 21, the first grounding area 22 and the second grounding area 31 due to long-term exposure to the air, thereby extending the service life of the signal transmission structure and ensuring the stability of signal transmission.

[0065] Furthermore, in this embodiment, the signal transmission structure is also cleverly integrated into the elastic film layer 6. This innovative design greatly enhances the ductility and scalability of the structure.

[0066] Specifically, the elastic film layer 6 is carefully arranged on the PI layer 52 on the first copper foil layer 2 and the second copper foil layer 3. By combining packaging technology with the flexible circuit board manufacturing process, it is ensured that the signal transmission structure can automatically rebound to its original state after stretching. This feature is crucial to achieving the scalability of the signal transmission structure.

[0067] In terms of material selection, the present invention has conducted extensive and in-depth research on the material of the elastic film layer 6. Optionally, the material of the elastic film layer 6 can be silicone rubber (PDMS), which is known for its excellent elasticity and durability; or the material of the elastic film layer 6 can be polyurethane, which is another ideal choice due to its excellent tensile strength and resilience; the material of the elastic film layer 6 can also be polystyrene copolymers, which are also applicable due to their good flexibility and processing performance.

[0068] Of course, the material of the elastic film layer 6 can also be natural rubber. Natural rubber, with its natural skin-friendliness and environmental protection characteristics, provides more possibilities for specific application scenarios. It can prevent the signal transmission structure from contacting with people with skin allergies and causing skin allergies in the application of wearable devices.

[0069] The selection of these materials not only meets the high requirements of the signal transmission structure for ductility and scalability, but also further broadens the application scope and market potential of the present invention. The present invention does not limit the selection of the material of the elastic film layer 6, and the designer can select it according to actual needs. All solutions that are the same or similar to the above-mentioned embodiments are covered within the protection scope of the present invention.

[0070] Preferably, in order to ensure the stability and efficiency of signal transmission, the spacing between the signal line area and the two first grounding areas in the present invention is strictly controlled and is not less than 35 um. Figure 4 As shown in , that is, the distance of S is not less than 35 um. This design takes into account the three aspects of process technology, transmission line impedance and compact structure.

[0071] Furthermore, the spacing between the two endpoints is carefully designed to be in the range of 200um to 400um, corresponding to Figure 4 and Figure 7 As shown in , the distance L is designed to be within the range of 200um to 400um. This setting not only ensures that the signal transmission structure has sufficient elastic deformation space when stretched, but also takes into account the structural strength and stability of signal transmission, which is an optimal balance between performance and reliability.

[0072] Further preferably, the spacing between any two adjacent hollow grooves 32 in the present invention is precisely controlled to be between 50um and 150um. Figure 6 and Figure 7 As shown, the distance between any two adjacent hollow grooves 32 is D, and the distance D is controlled between 50um and 150um. Such a design not only ensures sufficient stretching rate of the signal transmission structure, but also effectively avoids the increase of signal transmission loss caused by excessive spacing.

[0073] In this embodiment, the groove side wall of the hollow groove 32 in the cross section parallel to the second copper foil layer 3 may be in the shape of a square, a rhombus, a circle, etc. In the axial direction, the contour lines of two adjacent figures on the cross section have the shortest distance, and the distance D between two adjacent hollow grooves 32 is the shortest distance.

[0074] Considering that the signal transmission structure needs to exhibit excellent stretchability in practical applications, the present invention has finely optimized the overall thickness. Specifically, the thickness of the PI dielectric layer 1 is strictly controlled to be 15 to 50 um. Figure 4 As shown in , the thickness T is set at 15-50um. This design not only ensures the flexibility and reliability of the structure during the stretching process, but also significantly improves the wearing comfort of the user, providing strong support for applications in the fields of smart wearables, medical monitoring, etc.

[0075] The technical solution of the present invention is further described in detail below in conjunction with several preferred embodiments. The following embodiments are implemented on the premise of the technical solution of the invention and provide detailed implementation methods, but the protection scope of the present invention is not limited to the following embodiments. Example 1

[0076] (1) Set the thickness of the PI dielectric layer to 25um;

[0077] (2) The spacing between the signal line area and the two first ground areas is set to 35 um;

[0078] (3) The spacing between the two end points of the orthographic projection of the side wall of the hollow groove on the lower surface of the PI dielectric layer with the largest distance in the horizontal direction is set to 200 um;

[0079] (4) The spacing between any two adjacent hollow grooves is set to 141 um.

[0080] In this embodiment, the width of the signal line region in the lateral direction can reach 64 um. Example 2

[0081] (1) Set the thickness of the PI dielectric layer to 25um;

[0082] (2) The spacing between the signal line area and the two first ground areas is set to 35 um;

[0083] (3) The distance between the two end points of the orthographic projection of the side wall of the hollow groove on the lower surface of the PI dielectric layer with the largest distance in the horizontal direction is set to 300 um;

[0084] (4) The spacing between any two adjacent hollow grooves is set to 141 um.

[0085] In this embodiment, the width of the signal line region in the lateral direction can reach 77 um.

[0086] Comparative Example 1

[0087] In the present invention, this comparative example is also a conventional design in the prior art. In this comparative example, no hollow groove is provided on the second grounding area.

[0088] (1) Set the thickness of the PI dielectric layer to 25um;

[0089] (2) The spacing between the signal line area and the two first ground areas is set to 35 um.

[0090] In this comparative example, the width of the signal line region in the lateral direction is 45 um.

[0091] The comparative examples and embodiments of the present invention are provided with different parameters: ① PI dielectric layer thickness; ② the spacing between the signal line region and the two first grounding regions; ③ the spacing between the two endpoints of the orthographic projection of the sidewall of the hollow groove on the lower surface of the PI dielectric layer with the largest distance in the horizontal direction; ④ the spacing between any two adjacent hollow grooves. The width of the signal line region in the horizontal direction is obtained, and the specific results are shown in Table 1 below:

[0092] Table 1 Comparison of the width of the signal line area in the horizontal direction in Examples 1-2 and Comparative Examples

[0093] name Example 1 Example 2 Comparative Example PI dielectric layer thickness 25um 25um 25um The distance between the signal line area and the two first ground areas 35um 35um 35um The distance between the two end points of the orthographic projection of the side wall of the hollow groove on the lower surface of the PI dielectric layer with the largest distance in the transverse direction 200um 300um - The distance between any two adjacent hollow grooves 141um 141um - Horizontal width of the signal line area 64um 77um 45um

[0094] As shown in the table above, by setting the hollow groove and setting the spacing between the two end points to be more than 200um, the width of the signal line area in the horizontal direction can reach more than 64um. If the hollow groove is not set, the width of the signal line area in the horizontal direction can only be about 45um. The process requirement of about 45um is usually difficult to achieve by equipment, so more defects will occur.

[0095] In the present invention, the width of the signal line area in the lateral direction can be set larger by setting the hollow groove, so that the equipment can easily meet the accuracy required by the process, thereby reducing output defects.

[0096] Further, still refer to Figure 6 In order to achieve the best display, the signal line area 21 adopts a zigzag routing design. This unique layout not only enhances the flexibility of signal transmission, but also greatly promotes the stretchability of the overall structure. In order to match the zigzag routing of the signal line area 21, the two first grounding areas 22 and the second grounding area 31 are cleverly arranged at corresponding positions in a zigzag routing manner.

[0097] Specifically, the two first grounding regions 22 are respectively located on both sides of the signal line region 21, including a first side grounding region 221 and a second side grounding region 222. The first side grounding region 221 includes a plurality of first curved segments 2211 protruding from the second side grounding region 222 toward the first side grounding region 221, while the second side grounding region 222 includes a plurality of second curved segments 2221 protruding in the opposite direction.

[0098] In addition, the zigzag routing method of the present invention is not limited to a specific form, but can be flexibly selected according to actual needs, including but not limited to snake-shaped, sawtooth-shaped, wall-shaped and other routing methods.

[0099] Furthermore, the first protruding portion 2212 and the second protruding portion 2222 are respectively incorporated into the designs of the first curved section 2211 and the second curved section 2221 .

[0100] Specifically, the first protrusion 2212 is arranged on the side of the first curved section 2211 away from the signal line area 21, and the second protrusion 2222 is arranged on the side of the second curved section 2221 away from the signal line area 21. The first protrusion 2212 and the second protrusion 2222 both protrude in the direction away from the signal line area 21, and grounding holes are cleverly arranged thereon. These grounding holes become key nodes for electrically connecting the conductive member 4. One end of the conductive member 4 is firmly connected to the grounding hole, and the other end is electrically connected to the second grounding area 31. The alternating layout of the first protrusion 2212 and the second protrusion 2222 ensures that the grounding holes on the first side grounding area 221 and the second side grounding area 222 can be alternated in an orderly manner. This design is crucial to maintaining stable and reliable transmission of RF signals.

[0101] In order to further optimize the signal transmission performance, the present invention also provides an optional solution for metallizing the grounding hole. By metallizing the grounding hole, not only can the conductivity be enhanced, but also the first grounding area 22 and the second grounding area 31 can be effectively electrically connected to form an efficient microstrip transmission structure (Microstrip-Line). This structure performs well in high-frequency signal transmission, can significantly reduce signal loss, and improve the efficiency and quality of signal transmission.

[0102] Furthermore, the signal transmission structure is also specially provided with two static connection areas 7 at both ends of the signal line area 21, the first grounding area 22 and the second grounding area 31. These two areas are not only important components of the structure, but also bear key connection functions. Each static connection area 7 is firmly equipped with an auxiliary signal line area, a first auxiliary grounding area and a second auxiliary grounding area. The auxiliary signal line area is connected to one end of the signal line area 21, the first auxiliary grounding area is connected to one end of the first grounding area 22, and one end of the second auxiliary grounding area is connected to one end of the second grounding area 31. These auxiliary areas are precisely connected to the corresponding signal line areas and grounding areas to ensure the continuity and stability of signal transmission.

[0103] The static connection area 7 not only plays a role in connecting various areas, but also provides a stable fixed support for the entire signal transmission structure. This design not only enhances the integrity of the structure, but also effectively improves the reliability and durability of signal transmission.

[0104] In summary, the embodiments of the present invention achieve the following technical effects:

[0105] 1) Through the evenly spaced arrangement of multiple hollow grooves 32, the orthographic projection of the groove sidewall of the hollow groove 32 on the lower surface of the PI dielectric layer 1 has two endpoints with the largest distance in the horizontal direction, and the orthographic projection of the two sidewalls 211 on the lower surface is located between the two endpoints. On the one hand, the stretching rate of the signal transmission structure can be increased; on the other hand, the signal transmission loss can be reduced;

[0106] 2) By evenly spacing a plurality of hollow grooves 32, the orthographic projection of the groove sidewall of the hollow groove 32 on the lower surface of the PI dielectric layer 1 has two endpoints with the largest distance in the horizontal direction, and the orthographic projection of the two sidewalls 211 on the lower surface is located between the two endpoints. The width of the signal line area 21 can be set larger, thereby reducing the precision requirements for the processing equipment, and the process conditions are easier to meet, thereby improving the yield rate of the signal transmission structure;

[0107] 3) The signal line area 21 adopts a zigzag routing design, and the two first grounding areas 22 and the second grounding area 31 are cleverly arranged at corresponding positions in a zigzag routing manner, so that the signal transmission structure can evenly disperse stress during the stretching process, and effectively avoid structural damage caused by stress concentration;

[0108] 4) The grounding holes on the first-side grounding area 221 and the second-side grounding area 222 can be alternated in an orderly manner, and during the use of the signal transmission structure, the stable and reliable transmission of the radio frequency signal can be effectively maintained.

[0109] Obviously, the above-described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0110] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0111] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein.

[0112] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A signal transmission structure, characterized in that: The invention comprises a PI dielectric layer, a first copper foil layer and a second copper foil layer arranged on the upper and lower surfaces of the PI dielectric layer, wherein the first copper foil layer comprises a signal line area and two first grounding areas spaced apart from two side walls of the signal line area in a lateral direction, the second copper foil layer comprises a second grounding area arranged corresponding to the signal line area, a plurality of hollow grooves are evenly spaced apart on the second grounding area along the axial direction of the signal line area, the orthographic projection of the groove side wall of the hollow groove on the lower surface of the PI dielectric layer has two end points with the largest distance in the lateral direction, and the orthographic projections of the two side walls on the lower surface are located between the two end points, and the two end points are spaced apart from each other. The first grounding area is electrically connected to the second grounding area through a plurality of conductive members respectively provided through the PI dielectric layer. The signal line area is arranged along a zigzag pattern. The two first grounding areas and the second grounding area are arranged to match the zigzag pattern of the signal line area. The two first grounding areas include a first side grounding area located on one side of the signal line area and a second side grounding area located on the other side. The first side grounding area includes a plurality of first curved sections protruding from the second side grounding area toward the first side grounding area, and the second side grounding area includes a plurality of second curved sections protruding from the first side grounding area toward the second side grounding area.

2. The signal transmission structure according to claim 1, characterized in that: The hollow groove penetrates the second copper foil layer in a direction perpendicular to the second copper foil layer.

3. The signal transmission structure according to claim 1, characterized in that: The signal transmission structure further includes an anti-oxidation layer, which includes a glue layer and a PI layer. The glue layer covers the first copper foil layer and the second copper foil layer, and the PI layer is arranged on the glue layer.

4. The signal transmission structure according to claim 3, characterized in that: The signal transmission structure further includes an elastic film layer, and the elastic film layer is respectively disposed on the PI layer on the first copper foil layer and the second copper foil layer.

5. The signal transmission structure according to claim 1, characterized in that: The spacing between the signal line area and the two first grounding areas is no less than 35 um.

6. The signal transmission structure according to claim 1, characterized in that: The distance between the two end points is 200um to 400um.

7. The signal transmission structure according to claim 1, characterized in that: The distance between any two adjacent hollow grooves is 50um to 150um.

8. The signal transmission structure according to claim 1, characterized in that: The thickness of the PI dielectric layer is 15-50 um.

9. The signal transmission structure according to claim 1, characterized in that: A first protruding portion protruding away from the signal line area is formed on a side of the first curved section away from the signal line area, and a second protruding portion protruding away from the signal line area is formed on a side of the second curved section away from the signal line area. Grounding holes are provided on the first protruding portion and the second protruding portion, one end of the conductive member is electrically connected to the grounding hole, and the other end is electrically connected to the second grounding area.

10. The signal transmission structure according to claim 9, characterized in that: The signal transmission structure also includes two static connection areas arranged at both ends of the signal line area, the first grounding area and the second grounding area. An auxiliary signal line area, a first auxiliary grounding area and a second auxiliary grounding area are fixedly arranged on each static connection area. The auxiliary signal line area is connected to one end of the signal line area, the first auxiliary grounding area is connected to one end of the first grounding area, and one end of the second auxiliary grounding area is connected to one end of the second grounding area.

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