Flexible circuit board, watch strap and wearable device

Abstract

The present application provides a flexible circuit board, a watch strap and a wearable device, which relate to the technical field of electronic equipment. It is used to solve the problem that the stretchability of the electrical connection line of the existing wearable device is not ideal, which easily leads to the reduction of the reliability of the electrical connection between the functional module and the main board, and then causes the failure of the functional module, affecting the user experience. The above-mentioned flexible circuit board includes a circuit board body and an elastic bearing member. The circuit board body has a first end and a second end, the first end of the circuit board body is used to be electrically connected to the functional module, and the second end of the circuit board body is used to be electrically connected to the main board of the electronic device. The elastic bearing member has a bearing plane, and the circuit board body is attached to and fixed on the bearing plane. The circuit board body is bent and extended on the bearing plane.

Description

Technical Field

[0001] The present application relates to the technical field of electronic equipment, and in particular to a flexible circuit board, a watch strap and a wearable device. Background Art

[0002] With the continuous development of technology, wearable devices are gradually developing towards sports and medical purposes, thereby adding more functions to wearable devices. Therefore, some functional modules need to be integrated into the strap of the wearable device, and these functional modules need to be electrically connected to the main board through electrical connecting wires (for example, flexible circuit boards or wires). However, the stretchability of the electrical connecting wires is not ideal, which will reduce the reliability of the electrical connection between the functional modules and the main board, affecting the user experience. Summary of the invention

[0003] The embodiments of the present application provide a flexible circuit board, a watch strap and a wearable device, which are used to solve the problem that the stretchability of existing electrical connecting wires is not ideal, resulting in reduced reliability of the electrical connection between the functional module of the wearable device and the mainboard, affecting the user experience.

[0004] To achieve the above objectives, the embodiments of the present application adopt the following technical solutions:

[0005] In a first aspect, a flexible circuit board is provided, which includes a circuit board body and an elastic bearing member. The circuit board body has a first end and a second end, the first end of the circuit board body is used to be electrically connected to a functional module, and the second end of the circuit board body is used to be electrically connected to a mainboard of a wearable device. The elastic bearing member has a bearing plane, and the circuit board body is attached to and fixed on the bearing plane. The circuit board body is bent and extended on the bearing plane.

[0006] The flexible circuit board provided in the first aspect of the present application has the circuit board body disposed on the elastic bearing member, so that the circuit board body can be stretched or reset along with the elastic bearing member. Furthermore, since the circuit board body is bent and extended on the bearing plane, when the elastic bearing member is stretched, the circuit board body can be gradually stretched along with the elastic bearing member, thereby preventing the circuit board body from being broken or damaged.

[0007] In addition, the elastic bearing member has a bearing plane, and the circuit board body is attached to and fixed on the bearing plane, that is, the circuit board body bends and extends in the bearing plane, which does not increase the thickness along the direction perpendicular to the bearing plane, which is conducive to the thinning of the flexible circuit board.

[0008] In a possible implementation of the first aspect, the circuit board body forms a wavy structure on the load plane along the direction from the first end to the second end. Under this structure, when the elastic bearing member is stretched, the circuit board body can gradually stretch along the direction from the first end to the second end. When the elastic bearing member is reset, the circuit board body also restores the wavy structure. This is conducive to improving the stretchability of the circuit board body along the direction from the first end to the second end.

[0009] In a possible implementation of the first aspect, the surface of the elastic bearing member is a bearing plane, and the circuit board body is attached to and fixed on the surface of the elastic bearing member. Fixing the circuit board body on the surface of the elastic bearing member is conducive to reducing the difficulty of the processing technology, thereby facilitating improving production efficiency.

[0010] In a possible implementation of the first aspect, the circuit board body includes a dielectric layer, a metal layer, and a protective layer. The metal layer is stacked on both sides of the dielectric layer. The surface of the metal layer away from the dielectric layer is covered with the protective layer. Under this structure, the metal layer is provided on both sides of the dielectric layer, and the protective layer is covered on the metal layer, so that the metal layer is protected, which helps to improve the reliability of the circuit board body.

[0011] In a possible implementation of the first aspect, the circuit board body further includes a shielding layer, and the surface of the protective layer away from the metal layer is covered with the shielding layer. In this structure, the shielding layer is helpful to improve the electromagnetic shielding performance of the circuit board body, and is helpful to further improve the reliability of the circuit board body.

[0012] In a possible implementation of the first aspect, the circuit board body is embedded in the elastic bearing member, and the inside of the elastic bearing member is parallel to the circuit board body to form a bearing plane. In this structure, the circuit board body is embedded in the elastic bearing member, which can effectively protect the circuit board body.

[0013] In a possible implementation of the first aspect, the circuit board body includes a dielectric layer and a metal layer. The metal layer is provided on both side wall surfaces of the dielectric layer. In this structure, the dielectric layer and the metal layer are both embedded in the elastic bearing member, so there is no need to provide an additional protective layer or other structure, which is conducive to saving materials and reducing costs.

[0014] In addition, the circuit board body may further include a shielding layer, which is disposed on a side of the metal layer away from the dielectric layer and embedded in the elastic bearing member, thereby improving the electromagnetic shielding performance of the circuit board body.

[0015] In a possible implementation manner of the first aspect, the material of the elastic bearing member includes PDMS material, ecoflex material, PTFE material, SEBS material, biodegradable plastic or hydrogel.

[0016] In addition, the material of the dielectric layer may include one or more of PI material, PDMS material, biodegradable plastic, or hydrogel.

[0017] In a second aspect, a flexible circuit board is provided, which includes a circuit board body and an elastic bearing member. The circuit board body has a first end and a second end, the first end of the circuit board body is used to be electrically connected to the functional module, and the second end of the circuit board body is used to be electrically connected to the mainboard of the wearable device; a plurality of through slots are provided on the circuit board body, and the plurality of through slots are distributed at intervals. The elastic bearing member has a bearing plane, and the circuit board body is attached to and fixed on the bearing plane.

[0018] The flexible circuit board provided in the second aspect of the present application is advantageous in improving the stretchability of the circuit board body by opening a plurality of through grooves on the circuit board body, and each through groove runs through the two surfaces of the circuit board body in a direction perpendicular to the bearing plane. In addition, the circuit board body is fitted and fixed on the elastic bearing member, so that the circuit board body can be stretched or reset with the elastic bearing member to avoid the circuit board body being broken and lost. In addition, the elastic bearing member has a bearing plane, and the circuit board body is fitted and fixed on the bearing plane, so that the thickness dimension in the direction perpendicular to the bearing plane will not be increased, which is advantageous in thinning the flexible circuit board.

[0019] In a possible implementation of the second aspect, a plurality of groups of through grooves are provided on the circuit board body, each group of through grooves includes at least one through groove, and the plurality of groups of through grooves are distributed along the direction from the first end to the second end of the circuit board body. In this way, the plurality of groups of through grooves are distributed along the direction from the first end to the second end of the circuit board body, thereby improving the stretchability of the circuit board body along the direction from the first end to the second end, so that the circuit board body can be stretched or reset along with the elastic bearing member.

[0020] In a possible implementation of the second aspect, the plurality of through slots include a plurality of first through slots and a plurality of second through slots, each of the first through slots includes at least one first through slot, and each of the second through slots includes at least one second through slot; the plurality of first through slots and the plurality of second through slots are alternately distributed in sequence along the direction from the first end of the circuit board body to the second end; wherein the second through slots extend in a direction parallel to the bearing plane and perpendicular to the direction from the first end of the circuit board body to the second end, and penetrate the side wall of the circuit board body, and one second through slot only penetrates one side wall of the circuit board body. In this way, the first through slot is arranged in the middle of the circuit board body, and the second through slot forms a notch on the side wall of the circuit board body, thereby further improving the stretchability of the circuit board body along the direction from the first end to the second end.

[0021] In a possible implementation of the second aspect, the direction from the first end of the circuit board body to the second end is the first direction. The width of the through slot along the first direction is the first width, the width of the through slot along the direction parallel to the bearing plane and perpendicular to the first direction is the second width, and the first width is smaller than the second width. Under this structure, since the first width of the through slot is smaller than the second width, the circuit board body can be stretched better along the first direction, so that the circuit board body can be stretched and reset along the first direction with the elastic bearing member.

[0022] In a possible implementation of the second direction, the surface of the elastic bearing member is a bearing plane, and the circuit board body is attached to and fixed on the surface of the elastic bearing member. Fixing the circuit board body on the surface of the elastic bearing member is conducive to reducing the difficulty of the processing technology, thereby facilitating improving production efficiency.

[0023] In a possible implementation of the second direction, the circuit board body includes a dielectric layer, a metal layer and a protective layer. Metal layers are stacked on both sides of the dielectric layer. The surface of the metal layer away from the dielectric layer is covered with a protective layer. Under this structure, metal layers are arranged on both sides of the dielectric layer, and by covering the protective layer on the metal layer, the metal layer is protected, which helps to improve the reliability of the circuit board body.

[0024] In a possible implementation of the second direction, the circuit board body further includes a shielding layer, and the surface of the protective layer away from the metal layer is covered with the shielding layer. Under this structure, the shielding layer is helpful to improve the electromagnetic shielding performance of the circuit board body, and is helpful to further improve the reliability of the circuit board body.

[0025] In a possible implementation of the second direction, the circuit board body is embedded in the elastic bearing member, and the inside of the elastic bearing member is parallel to the circuit board body to form a bearing plane. In this structure, the circuit board body is embedded in the elastic bearing member, which can effectively protect the circuit board body.

[0026] In a possible implementation of the second direction, the circuit board body includes a dielectric layer and a metal layer. The metal layer is provided on both side wall surfaces of the dielectric layer. In this structure, the dielectric layer and the metal layer are both embedded in the elastic bearing member, so there is no need to provide an additional protective layer or other structure, which is conducive to saving materials and reducing costs.

[0027] In addition, the circuit board body may further include a shielding layer, which is disposed on a side of the metal layer away from the dielectric layer and embedded in the elastic bearing member, thereby improving the electromagnetic shielding performance of the circuit board body.

[0028] In a possible implementation manner of the second aspect, the material of the elastic supporting member includes PDMS material, biodegradable plastic or hydrogel.

[0029] In addition, the material of the dielectric layer may include PI material or PDMS material, biodegradable plastic or hydrogel, etc.

[0030] In a third aspect, a flexible circuit board is provided, which includes a circuit board body and an elastic bearing member. The circuit board body has a first end and a second end, the first end of the circuit board body is used to connect to the functional module, and the second end of the circuit board body is used to electrically connect to the mainboard of the wearable device. The direction from the first end of the flexible circuit board to the second end is the length direction of the elastic bearing member, the circuit board body is wound around the elastic bearing member and extends along the length direction of the elastic bearing member, and the circuit board body is fixedly connected to the elastic bearing member.

[0031] The flexible circuit board provided in the third aspect of the present application forms a nearly spiral structure by winding the circuit board body around the elastic bearing member and extending along the length direction of the elastic bearing member, thereby facilitating the improvement of the stretchability of the circuit board body. In addition, since the elastic bearing member has good elasticity, when the elastic bearing member is stretched along its length direction, the circuit board body can gradually stretch along with the elastic bearing member, and when the elastic bearing member is reset, the circuit board body can also be reset synchronously, thereby reducing the risk of the circuit board body being overstretched or being broken and damaged.

[0032] In a possible implementation of the third aspect, the circuit board body is attached to and fixed on the surface of the elastic bearing member. In this structure, the circuit board body can be fixed to the surface of the elastic bearing member by gluing or other methods, which is conducive to reducing the process difficulty and improving production efficiency.

[0033] In a possible implementation of the third aspect, a receiving groove is provided on the surface of the elastic bearing member, the extending direction of the receiving groove is the same as the extending direction of the circuit board body, and the circuit board body is disposed in the receiving groove. This facilitates electroplating of metal material in the receiving groove to form the above-mentioned metal layer, thereby reducing the difficulty of the process.

[0034] In a possible implementation of the third aspect, the circuit board body is embedded in the elastic bearing member. That is, the circuit board body is inside the elastic bearing member, around the axis of the elastic bearing member (i.e., the axis parallel to the length direction of the elastic bearing member), and extends along the length direction of the elastic bearing member. Thus, a nearly spiral structure is formed inside the elastic bearing member, and can be stretched and reset along with the elastic bearing member. In this way, by embedding the circuit board body inside the elastic bearing member, the circuit board body can be effectively protected, which is conducive to improving the reliability of the flexible circuit board.

[0035] In a possible implementation manner of the third aspect, a cross section of the elastic bearing member along a direction perpendicular to the length direction is circular, regular polygonal, or elliptical.

[0036] In a possible implementation manner of the third aspect, a cross section of the elastic bearing member along a direction perpendicular to the length direction is circular.

[0037] In a fourth aspect, a watch strap is provided for a wearable device, the watch strap comprising a watch strap body, a functional module and a flexible circuit board. The functional module is disposed on the watch strap body. The flexible circuit board is a flexible circuit board as described in any of the above technical solutions, the flexible circuit board is embedded in the watch strap body, and the circuit board body of the flexible circuit board is electrically connected to the functional module.

[0038] The watch strap provided in the fourth aspect of the present application, because it includes the flexible circuit board described in any of the above technical solutions, can solve the same technical problem and achieve the same technical effect.

[0039] In a possible implementation of the fourth aspect, the functional module includes a sensor, a display module, a camera module, a solar charging module or a pulse module.

[0040] In a fifth aspect, a wearable device is provided, comprising a dial, a main board and a watch strap. The main board is disposed in the dial. The watch strap is the watch strap provided in the fourth aspect above, the watch strap is connected to the dial, and the flexible circuit board is electrically connected to the main board.

[0041] The wearable device provided in the fifth aspect of the present application, because it includes the watch strap provided in the fourth aspect, can solve the same technical problem and achieve the same technical effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 A structural diagram of a wearable device provided in an embodiment of the present application;

[0043] Figure 2 An exploded view of a wearable device (the strap is not shown) provided in an embodiment of the present application;

[0044] Figure 3 A structural diagram of a watch strap provided in an embodiment of the present application;

[0045] Figure 4 A structural diagram of another watch strap provided in an embodiment of the present application;

[0046] Figure 5 for Figure 4 A structural diagram of a flexible circuit board provided in a watch strap;

[0047] Figure 6 for Figure 5 A cross-sectional structural diagram of the provided flexible circuit board;

[0048] Figure 7 for Figure 5 A cross-sectional structural diagram of another circuit board body of the provided flexible circuit board;

[0049] Figure 8 for Figure 5 A cross-sectional structural diagram of another circuit board body of the provided flexible circuit board;

[0050] Fig. 9 for Figure 6 A cross-sectional structural diagram of a flexible circuit board body provided in which the circuit board body is embedded in an elastic bearing member;

[0051] Fig.10 A cross-sectional structural diagram of a circuit board substrate provided in an embodiment of the present application;

[0052] Fig.11 for Fig.10 A structural diagram of a metal layer with a wavy structure formed on a dielectric layer is provided;

[0053] Fig.12 for Fig.11 An enlarged structural diagram of a metal layer including a plurality of metal wires is provided;

[0054] Fig.13 for Fig.11 A partial structural diagram of the metal layer provided;

[0055] Fig.14 A structural diagram of a circuit board body made for an embodiment of the present application;

[0056] Fig.15 A structural diagram of another watch strap is provided for an embodiment of the present application;

[0057] Fig.16 A structural diagram of another circuit board body provided in an embodiment of the present application;

[0058] Fig.17 for Fig.16 The structure diagram of the flexible circuit board after being stretched along the first direction;

[0059] Fig.18 for Fig.16 Another distribution structure diagram of the through grooves on the circuit board body of the provided flexible circuit board;

[0060] Fig.19 for Fig.18 A structural diagram of a circuit board body provided after being stretched along a first direction;

[0061] Fig. 20 A structural diagram of a circuit board substrate provided in an embodiment of the present application with a dry film and a developing area;

[0062] Fig.21 for Fig. 20 A structural diagram of a through groove formed on a provided circuit board substrate;

[0063] Fig. 22 A structural diagram of another watch strap provided in an embodiment of the present application;

[0064] Fig.23 for Fig. 22 A diagram of the structure of the flexible circuit board in the provided watch strap;

[0065] Fig.24 A structural diagram of another elastic bearing member provided in an embodiment of the present application;

[0066] Fig.25 A structural diagram of a circuit board substrate provided in an embodiment of the present application, wherein a metal layer is processed into a plurality of metal circuits;

[0067] Fig.26 for Fig.25 A circuit board substrate is provided to form a structural diagram of a circuit board body having a plurality of parallel metal lines;

[0068] Fig. 27 A structural diagram of a plurality of grooves formed on a substrate provided in an embodiment of the present application;

[0069] Fig.28 for Fig. 27 A structural diagram of the substrate provided after being folded in half;

[0070] Fig.29 for Fig.28 A structural diagram of an elastic bearing member formed by a cylindrical substrate is provided;

[0071] Fig.30 for Fig.29 A cross-sectional structural diagram of the elastic bearing member along its axial direction is provided;

[0072] Fig.31 for Fig.30 A structural diagram of a circuit board body formed in a spiral groove of a provided elastic bearing member;

[0073] Fig.32 for Fig.31 A cross-sectional structure of a protective layer and a shielding layer provided on the outer side of the flexible circuit board along its radial direction;

[0074] Fig.33 A structural diagram of an elastic bearing member of a cylindrical structure provided in an embodiment of the present application;

[0075] Fig.34 for Fig.33 A cross-sectional view of a metal layer formed on the surface of a resilient bearing member is provided;

[0076] Fig.35 for Fig.34 A cross-sectional structural diagram along the radial direction of the elastic bearing member;

[0077] Fig.36 for Fig.35 A schematic diagram of the structure for cutting the provided metal layer;

[0078] Fig.37 for Fig.34 The structural diagram of the spiral structure film layer formed on the surface;

[0079] Fig.38 for Fig.37 A cross-sectional structural diagram along the axial direction of the elastic bearing member;

[0080] Fig.39 For Fig.37 and Fig.38 A structural diagram of a circuit board body formed by etching a metal layer provided with a spiral structure film layer.

[0081] Figure markings: 01-wearable device; 10-dial; 11-shell; 111-middle frame; 112-back cover; 12-display module; 121-light-transmitting cover; 122-display screen; 20-main board; 30-watch strap; 31-first part; 32-second part; 40-functional module; 50-flexible circuit board; 51-circuit board body; 51a-through groove; 51b-first through groove; 51c-second through groove; 511-dielectric layer; 512-metal layer; 513-protective layer; 514-shielding layer; 52-elastic bearing member; 52a-bearing plane; 52b-accommodating groove; 60-connector; 70-circuit board substrate; 71-seed layer; 72-substrate; 72a-groove body; 72b-spiral groove. DETAILED DESCRIPTION

[0082] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments.

[0083] In the following, the terms "first", "second", etc. are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first", "second", etc. may explicitly or implicitly include one or more of the features.

[0084] In addition, in the present application, directional terms such as "upper" and "lower" are defined relative to the orientation of the components in the drawings. It should be understood that these directional terms are relative concepts. They are used for relative description and clarification, and they can change accordingly according to the changes in the orientation of the components in the drawings.

[0085] In the present application, unless otherwise clearly specified and limited, the term "connection" should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection or an indirect connection through an intermediate medium.

[0086] The present application provides a wearable device, which may be a smart watch, a smart bracelet, etc. For the convenience of description, the following detailed description is given by taking the smart watch as an example.

[0087] See also Figure 1 and Figure 2 , Figure 1 This is a structural diagram of the wearable device 01 provided in an embodiment of the present application. Figure 2 The exploded view of the dial 10 provided in the embodiment of the present application. In the present embodiment, the wearable device 01 may include a dial 10, a mainboard 20 and a strap 30. The dial 10 may include a housing 11 and a display module 12.

[0088] The shell 11 is used to protect the electronic components inside the wearable device 01. The shell 11 includes a middle frame 111 and a back cover 112. The back cover 112 and the display module 12 are respectively located on both sides of the middle frame 111, and the back cover 112 is fixedly connected to the middle frame 111. Exemplarily, the back cover 112 and the middle frame 111 can be fixed by bonding, clamping, welding or threaded connection. Alternatively, the middle frame 111 can also be an integrally formed structure with the back cover 112, that is, the middle frame 111 and the back cover 112 are a whole structural component.

[0089] Furthermore, the materials of the middle frame 111 and the back cover 112 include but are not limited to metal, ceramic, plastic and glass. Furthermore, the material of the middle frame 111 and the material of the back cover 112 may be the same or different. Therefore, this application does not make any special limitation on this.

[0090] The display module 12 is used to display images, etc. The display module 12 may include a transparent cover plate 121 and a display screen 122 (or a display panel). Specifically, the transparent cover plate 121 may be an ordinary transparent cover plate 121, which is used to protect the display screen 122 to prevent the display screen 122 from being damaged due to external force collision, and can also play a dustproof role; a transparent cover plate 121 with a touch function may also be used to enable the electronic device to have a touch function, thereby making it more convenient for users to use. Therefore, the present application does not specifically limit the specific material of the transparent cover plate 121.

[0091] In addition, the display screen 122 may be a flexible display screen or a rigid display screen. For example, the display screen 122 may be an organic light-emitting diode (OLED) display screen, an active-matrix organic light-emitting diode or an active-matrix organic light-emitting diode (AMOLED) display screen, a mini light-emitting diode (LED) display screen, a micro organic light-emitting diode (OLED) display screen, a micro organic light-emitting diode (OLED) display screen, a quantum dot light-emitting diode (QLED) display screen, or a liquid crystal display (LCD) display screen, etc.

[0092] The mainboard 20 is disposed inside the housing 11 and is used to realize electrical connection between electronic components inside the wearable device 01. For example, the electronic components may include a control chip, a camera module, and the like.

[0093] The strap 30 is used to wear the wearable device 01 on the user's wrist. For example, the strap 30 can be a whole, and its two ends are movably connected to the two sides of the housing 11 of the dial 10, and the user can wear it on the wrist by the stretchability of the strap 30 material.

[0094] Alternatively, continue to Figure 1 and Figure 2The watch strap 30 may include a first portion 31 and a second portion 32, which are respectively disposed on both sides of the housing 11 of the dial 10 and are movably connected to the housing 11; and the first portion 31 and the second portion 32 may be connected via a through slot 51a and a buckle, so that the user can wear the wearable device 01 on the wrist. The present application does not specifically limit the specific structure of the watch strap 30.

[0095] As user demands continue to increase, wearable devices 01 are gradually developing towards sports and medical purposes. Figure 3 , Figure 3 This is a structural diagram of a watchband 30 provided in an embodiment of the present application. Some functional modules 40 can be integrated on the watchband 30 of the wearable device 01 to enable the wearable device 01 to have more functions. For example, the functional module 40 can be a heart rate monitoring sensor, through which the heart rate monitoring sensor can monitor the heart rate of the wearer. In addition, the display module 12 on the wearable device 01 can display the monitoring results so that the user can view them at any time.

[0096] For some examples, see Figure 3 The functional module 40 can be arranged on the strap 30 so that the functional module 40 can be close to the pulse of the user to ensure the accuracy of the monitoring result. When the functional module 40 is arranged on the strap 30, the functional module 40 and the main board 20 need to be electrically connected through a flexible circuit board 50 or other electrical connection lines to facilitate signal transmission between the main board 20 and the functional module 40.

[0097] However, in some application scenarios of the wearable device 01, the strap 30 will be stretched. For example, for the wearable device 01 with the strap 30 forming an integral structure, since the two ends of the strap 30 are respectively rotatably connected to the two sides of the housing 11, that is, the device as a whole forms a closed loop structure, when the user wears it, the user needs to put the device as a whole on the palm and move it to the wrist. In this process, when the device passes through the palm, it will be expanded by the palm, that is, the strap 30 will be stretched, so that the device can be moved to the user's wrist.

[0098] Based on this, during the stretching of the strap 30, the flexible circuit board 50 disposed inside the strap 30 will also be stretched along with the strap 30. Therefore, there is a risk of the flexible circuit board 50 being broken during the stretching process, thereby reducing the reliability of the electrical connection between the above-mentioned functional module 40 and the main board 20.

[0099] In order to solve the above technical problems, an embodiment of the present application provides a flexible circuit board 50, which has good stretchability. The flexible circuit board 50 is embedded in the above-mentioned strap 30. When the strap 30 is stretched, the flexible circuit board 50 can be stretched together with the strap 30, which is beneficial to improving the reliability of the electrical connection between the functional module 40 and the main board 20.

[0100] See also Figure 4 and Figure 5 , Figure 4 This is a structural diagram of another watch strap 30 provided in an embodiment of the present application. Figure 5 for Figure 4 A structural diagram of a flexible circuit board 50 provided in a watch band 30 is provided. The flexible circuit board 50 may include a circuit board body 51 and an elastic bearing member 52. The circuit board body 51 has a first end and a second end, the first end of the circuit board body 51 is used to be electrically connected to the functional module 40, and the second end of the circuit board body 51 is used to be electrically connected to the main board 20. The elastic bearing member 52 has a bearing plane 52a, and the circuit board body 51 is attached to and fixed on the bearing plane 52a of the elastic bearing member 52.

[0101] In some embodiments, the circuit board body 51 may be bent and extended on the bearing plane 52a. For example, the circuit board body 51 may form a wavy structure on the bearing plane 52a along the direction from the first end of the circuit board body 51 to the second end (i.e., the length direction of the strap 30).

[0102] Furthermore, the elastic bearing member 52 may be made of one or more of PDMS (polydimethylsiloxane), ecoflex (platinum catalyzed silica gel), PTFE (polytetrafluoroethylene), SEBS (Styrene Ethylene Buty lene Styrene, a linear triblock copolymer with polystyrene as the terminal segment and ethylene-butene copolymer obtained by hydrogenation of polybutadiene as the middle elastic segment), biodegradable plastics or hydrogel. These materials have good elastic properties, so as to facilitate the stretching and resetting of the circuit board body 51.

[0103] In this way, since the circuit board body 51 is fixed on the bearing plane 52a of the elastic bearing member 52 with good elastic performance, and the circuit board body 51 bends and extends in the bearing plane 52a, that is, it bends and extends repeatedly in a wavy structure. When the elastic bearing member 52 is stretched, the circuit board body 51 can be stretched from the wavy structure to the straight structure, that is, the circuit board body 51 can be stretched to a straight structure. When the elastic bearing member 52 is reset, the circuit board body 51 is reset synchronously, that is, it returns to the wavy bending structure. Therefore, in the process of the circuit board body 51 gradually stretching with the elastic bearing member 52, the circuit board body 51 only gradually stretches from the bending state to the straight state, and the circuit board body 51 itself is not subjected to a large tensile force, which is conducive to improving the stretchability of the flexible circuit board 50, so as to reduce the risk of the flexible circuit board 50 being broken and damaged, and further improve the reliability of the electrical connection between the above-mentioned functional module 40 and the main board 20.

[0104] It is understandable that the wavy structure formed by the circuit board body 51 on the bearing plane 52a of the elastic bearing member 52 can have each of the waveform vertices formed by the same bending radius and bending angle. Alternatively, each of the waveform vertices can also be set to different bending radii and bending angles. The specific structure can be designed and changed according to the specific usage scenario, so this application does not make any special restrictions on this.

[0105] In addition, the circuit board body 51 may be made of FCCL (Flexible Copper Clad Laminate), such as single-layer copper clad laminate, double-layer copper clad laminate or multi-layer copper clad laminate, etc. The following is a detailed description of the circuit board body 51 using a double-layer copper clad laminate as an example.

[0106] Specifically, see Figure 6 , Figure 6 for Figure 5 A cross-sectional structural diagram of a flexible circuit board 50 is provided. The circuit board body 51 may include a dielectric layer 511 and a metal layer 512. The metal layer 512 is stacked on both sides of the dielectric layer 511. The metal layer 512 may be made of copper or other metal materials. The dielectric layer 511 may be made of PI (Polyimide) material, PDMS material, LCP (Liquid Crystal Polymer) material, MPI (Modified Polyimide) material, ecoflex material, hydrogel, etc.

[0107] To further effectively protect the metal layer 512, please refer to Figure 7 , Figure 7 for Figure 5 Another cross-sectional structural diagram of a circuit board body 51 of a flexible circuit board 50 is provided, wherein the circuit board body 51 may further include a protective layer 513, and the surface of the metal layer 512 away from the dielectric layer 511 is covered with the protective layer 513. For example, the protective layer 513 may be made of PI material. Thus, the metal layer 512 is located between the protective layer 513 and the dielectric layer 511, so as to effectively protect the metal layer 512.

[0108] In addition, to further improve the electromagnetic shielding performance of the circuit board body 51, please refer to Figure 8 , Figure 8 for Figure 5 A cross-sectional structure diagram of another circuit board body 51 of the flexible circuit board 50 is provided, wherein the circuit board body 51 may further include a shielding layer 514, which is disposed on a surface of the protective layer 513 away from the metal layer 512. For example, the shielding layer 514 may be made of EMI (Electromagnetic Interference Shielding, electromagnetic interference shielding material), thereby facilitating the improvement of the electromagnetic shielding performance of the circuit board body 51.

[0109] On this basis, please continue to refer to Figure 6 , Figure 7 and Figure 8 The circuit board body 51 can be bonded and fixed on the surface of the elastic bearing member 52. At this time, the surface of the elastic bearing member 52 is the bearing plane 52a. Fixing the circuit board body 51 on the surface of the elastic bearing member 52 is conducive to reducing the process difficulty and improving production efficiency.

[0110] Alternatively, see Fig. 9 , Fig. 9 for Figure 6 A cross-sectional structural diagram of a circuit board body 51 of a flexible circuit board 50 is provided, which is embedded in an elastic bearing member 52. The circuit board body 51 can also be embedded in the elastic bearing member 52. In this case, the plane inside the elastic bearing member 52 that fits the circuit board body 51 forms the bearing plane 52a. That is, the elastic bearing member 52 wraps the circuit board body 51 inside, thereby providing further protection for the circuit board body 51.

[0111] It should be noted that when the circuit board body 51 is embedded in the elastic bearing member 52 , the circuit board body 51 may not be provided with the protective layer 513 . The elastic bearing member 52 can effectively protect the circuit board body 51 .

[0112] The above is a description of the specific structure of the flexible circuit board 50 provided in the embodiment of the present application. The following is a detailed description of the method for manufacturing the flexible circuit board 50. The method for manufacturing the flexible circuit board 50 may include the following steps:

[0113] Step 1: Use a double-layer copper-clad board, that is, both sides of the dielectric layer 511 are provided with a metal layer 512, and laminated by a lamination process to form a double-layer circuit board substrate 70. Fig.10 , Fig.10 This is a cross-sectional structural diagram of a circuit board substrate 70 provided in an embodiment of the present application.

[0114] For example, the thickness of the dielectric layer 511 may be 12.5 μm, and the thickness of the metal layer 512 may be 12 μm. This embodiment of the present application does not specifically limit this.

[0115] Step 2: Process the metal layer 512 of the circuit board substrate 70 so that the metal layers 512 on both sides of the dielectric layer 511 form the wavy structure. Fig.11 , Fig.11 for Fig.10 A structural diagram of a metal layer 512 with a wavy structure formed on a dielectric layer 511 is provided.

[0116] For example, the metal layer 512 can be processed by lamination, exposure, development, etching and other processes, so that the metal layer 512 forms a metal wire with a wavy structure on the surface of the dielectric layer 511. Fig.12 and Fig.13 , Fig.12 for Fig.11 The metal layer 512 includes a magnified structure diagram of a plurality of metal lines, Fig.13 for Fig.11 A partial structural diagram of the metal layer 512 is provided. The metal wire of the wavy structure formed by the metal layer 512 may include a plurality of metal wires arranged at equal intervals, and the metal wire width may be w=60μm, the spacing between the metal wires may be y=100μm, the bending radius at the vertex of the waveform formed by the metal wire may be R=5mm, the bending angle may be α=20°, and the length distance between the end of the waveform vertex to the end of another adjacent waveform vertex may be l=5mm. It is understood that the above parameters are only used for illustrative purposes of this embodiment and do not form a special limitation on the structure provided in the embodiment of the present application.

[0117] Then, the dielectric layer 511 is sheared so that the dielectric layer 511 forms a wavy structure similar to that of the metal layer 512, thereby forming the circuit board body 51. Fig.14 , Fig.14This is a structural diagram of the circuit board body 51 manufactured in the embodiment of the present application. For example, the dielectric layer 511 can be cut by laser ablation, femtosecond laser cutting or punching.

[0118] Alternatively, a groove of a wavy structure may be first pressed on the dielectric layer 511 by a nano-indentation process, and then a metal layer 512 may be formed in the groove by an electroplating process. Specifically, a titanium copper seed metal layer may be first sputtered on the inner wall of the groove, and then metal copper may be electroplated on the seed layer 71 to form the metal layer 512. Alternatively, a sputtering process may be used to directly sputter metal copper in the groove to form the metal layer 512.

[0119] Step 3: On the surface of the metal layer 512 away from the dielectric layer 511, a protective layer 513 and a shielding layer 514 are provided by a lamination process to form a Figure 7 or Figure 8 The circuit board body 51 is shown.

[0120] For example, PI material can be used as the protective layer 513, and silver foil can be used as the shielding layer 514. Then, the protective layer 513 and the shielding layer 514 are cut by stamping, laser cutting or other processes to form a wavy structure similar to the metal layer 512 and the dielectric layer 511. Thus, the circuit board body 51 is formed.

[0121] Step 4: The circuit board body 51 is bonded and fixed to the surface of the elastic supporting member 52 , or embedded in the elastic supporting member 52 .

[0122] Specifically, the circuit board body 51 can be bonded and fixed to the bearing plane 52a of the elastic bearing member 52 by gluing, or the bearing plane 52a of the elastic bearing member 52 can be heated so that the elastic bearing member 52 is bonded and fixed to the circuit board body 51 by its own adhesiveness, so as to form a Figure 8 The flexible circuit board 50 is shown.

[0123] It should be noted that the circuit board body 51 can be embedded in the elastic supporting component 52 by forming a recessed structure on the surface of the elastic supporting component 52, fixing the circuit board body 51 in the recessed structure, and then filling the recessed structure with the material of the elastic supporting component 52 to achieve the circuit board body 51 being embedded in the elastic supporting component 52.

[0124] Alternatively, the circuit board body 51 may be disposed between two layers of elastic supporting members 52 , that is, the two layers of elastic supporting members 52 wrap the circuit board body 51 and then fixed by a pressing process, so that the circuit board body 51 is embedded in the elastic supporting member 52 .

[0125] In addition, since the circuit board body 51 is embedded in the elastic bearing member 52, the circuit board body 51 may not include the protective layer 513. Therefore, in this case, the above step 3 may be deleted, thereby forming the following: Fig. 9 The flexible circuit board 50 is shown.

[0126] Step 5: electrically connect the circuit board body 51 of the flexible circuit board 50 to the functional module 40 , and embed the flexible circuit board 50 and the functional module 40 inside the strap 30 .

[0127] Specifically, the circuit board body 51 and the functional module 40 can be electrically connected by using SMT (Surface Mounted Technology) patch technology, hotbar (hot pressing tin melting welding) technology, laser welding, ACF (anisotropic conductive film) technology, etc. Then, the flexible circuit board 50 and the functional module 40 are encapsulated in the strap 30 by integrated injection molding, so as to form a Figure 4 The strap 30 is shown.

[0128] The circuit board body 51 and the main board 20 may be directly or indirectly electrically connected. Fig.15 , Fig.15 Another structural diagram of a watch band 30 is provided for the embodiment of the present application. The circuit board body 51 of the flexible circuit board 50 can be electrically connected to the main board 20 with a connector 60 such as a spring, a BTB connector, a Pogo Pin (spring pin) or a ZIF (compression data connection line).

[0129] In this case, the connector 60 and the functional module 40 can be electrically connected to the circuit board body 51. Then, the flexible circuit board 50, the functional module 40 and the connector 60 are packaged in the strap 30 by integrated injection molding.

[0130] Finally, the watch strap 30 is connected to the watch dial 10, and the flexible circuit board 50 or the connector 60 is electrically connected to the main board 20, so as to form the wearable device 01.

[0131] The wearable device 01 provided in the embodiment of the present application has good stretchability of the flexible circuit board 50 inside the strap 30. Therefore, when the user stretches the strap 30 during use, the risk of the flexible circuit board 50 being broken and damaged can be reduced, thereby reducing the risk of failure of the functional module 40, which is conducive to improving the user experience.

[0132] Based on this, in other embodiments, the circuit board body 51 of the above-mentioned flexible circuit board 50 can also improve the stretchability of the circuit board body 51 by providing a through groove 51a. Fig.16 , Fig.16 The structural diagram of another circuit board body 51 provided in the embodiment of the present application, the circuit board body 51 may be provided with a plurality of through slots 51a, and the plurality of through slots 51a are spaced apart. The circuit board body 51 is attached to and fixed on the bearing plane 52a of the elastic bearing member 52. The direction from the first end of the circuit board body 51 to the second end is the first direction ( Fig.16 The direction parallel to the carrying plane 52a and perpendicular to the first direction is the second direction ( Fig.16 X direction).

[0133] The through slots 51a may include multiple groups of through slots 51a, each group of through slots 51a includes at least one through slot 51a, and when each group of through slots 51a includes multiple through slots 51a, the multiple through slots 51a are distributed at intervals along the second direction. The multiple groups of through slots 51a are distributed along the direction from the first end of the circuit board body 51 to the second end (i.e., the first direction).

[0134] In this way, since a plurality of through slots 51a are provided on the circuit board body 51, the circuit board body 51 forms a plurality of hollow structures, and the circuit board body 51 can form a continuous bending structure along the first direction (Y direction). Fig.17 , Fig.17 for Fig.16 The structure diagram of the flexible circuit board 50 after being stretched along the first direction shows that when the circuit board body 51 is stretched along the first direction, the width of the through slot 51a along the first direction can be gradually increased, and the through slot 51a is gradually bent along the edge perpendicular to the first direction. However, the circuit board body 51 will not bear a large tensile force, thereby improving the stretchability of the circuit board body 51.

[0135] When the flexible circuit board 50 is stretched along with the strap 30, the elastic bearing member 52 is stretched, and the circuit board body 51 is stretched synchronously with the elastic bearing member 52. The circuit board body 51 has improved stretchability through multiple through slots 51a, so during the stretching process, the circuit board body 51 will not be subjected to a large stretching force, thereby helping to reduce the risk of the circuit board body 51 being broken and damaged during the stretching process. When the external force of the strap 30 is eliminated, the elastic bearing member 52 is reset, and drives the circuit board body 51 to reset synchronously.

[0136] To further improve the stretchability of the circuit board body 51, please continue to refer to Fig.16 and Fig.17 The width of the through slot 51a on the circuit board body 51 along the first direction is Fig.16 The width along the direction parallel to the bearing plane 52a and perpendicular to the first direction (ie, the second direction mentioned above) is Fig.16The second width D2 is shown. The first width D1 is smaller than the second width D2. In this way, since the second width of the through slot 51a increases, when the circuit board body 51 is stretched along the first direction, the range of the first width of the through slot 51a along the first direction increases, thereby further improving the stretchability of the circuit board body 51 along the first direction.

[0137] Also, see Fig.18 , Fig.18 for Fig.16 Another distribution structure diagram of the through slots 51a on the circuit board body 51 of the flexible circuit board 50 is provided, wherein the through slots 51a may include multiple groups of first through slots 51b and multiple groups of second through slots 51c, each group of first through slots 51b includes at least one first through slot 51b, and each group of second through slots 51c includes at least one second through slot 51c. Multiple groups of first through slots 51b and multiple groups of second through slots 51c are alternately arranged in sequence along the first direction. That is, a group of first through slots 51b, a group of second through slots 51c, a group of first through slots 51b, and a group of second through slots 51c are arranged in sequence along the first direction, and are distributed in sequence according to this rule.

[0138] The second through slot 51c extends along the second direction and penetrates a side wall of a circuit board body 51. That is, the second through slot 51c penetrates a side wall arranged along the first direction, that is, the second through slot 51c forms a notch on a side wall along the first direction. Moreover, a second through slot 51c forms a notch only at a side wall on the circuit board body 51, thereby ensuring that the circuit board body 51 forms a continuous structure along the first direction, so as to avoid a discontinuity point in the middle of the circuit board body 51, thereby avoiding failure of the circuit board body 51.

[0139] For example, please refer to Fig.18 One first through slot 51b is provided in each group of the first through slots 51b, two second through slots 51c are provided in each group of the second through slots 51c, and the two second through slots 51c are distributed along the second direction, and the second through slots 51c respectively penetrate the two side edges extending along the first direction of the circuit board body 51.

[0140] The circuit board body 51 has a width dimension b=20 mm, a length dimension L=120 mm, a length w=15 mm of the first through slot 51 b, a length w / 2=7.5 mm of the second through slot 51 c, and a width c=5 mm of the first through slot 51 b and the second through slot 51 c. In addition, the circuit board body 51 can be divided into a plurality of unit areas along the first direction, each unit area is provided with a group of first through slots 51 b and a group of second through slots 51 c, and a width d=20 mm of a unit area.

[0141] In this way, please refer to Fig.19 , Fig.19 for Fig.18 A structural diagram of the circuit board body 51 after being stretched along the first direction is provided. When the circuit board body 51 is stretched along the first direction, each group of first through grooves 51b is gradually separated from the middle along the first direction, and two adjacent second through grooves 51c are gradually separated from the openings on the two side edges, which is conducive to improving the stretchability of the circuit board body 51, so that the stretchable distance of the circuit board body 51 along the first direction is increased, which is conducive to further reducing the risk of the flexible circuit board 50 being broken and damaged.

[0142] It should be noted that the hierarchical structure of the circuit board body 51, the supporting material of the elastic bearing member 52, and the manufacturing method of the flexible circuit board 50 are the same as those of the flexible circuit board 50 provided in the above embodiment. The difference between the two is only the shape of the circuit board body 51, and the difference in the manufacturing method is only the shape of the cutting.

[0143] That is, in the above step 2, a dry film is firstly provided on the circuit board substrate 70, and a developing area is formed. Fig. 20 , Fig. 20 The structure diagram of the circuit board substrate 70 provided in the embodiment of the present application is provided with a dry film and a developing area. Fig.21 , Fig.21 for Fig. 20 The structure diagram of the through groove 51a is provided on the circuit board substrate 70, and the developed area is etched to form the through groove 51a. At this time, the metal layer 512 forms the metal wire. Next, the dry film is peeled off and the dielectric layer 511 is cut to form Fig.16 or Fig.18 Therefore, the same structure and manufacturing steps of the flexible circuit board 50 as those of the above-mentioned embodiment will not be described repeatedly.

[0144] The circuit board body 51 of the above flexible circuit board 50 is formed into a planar structure, that is, fixed on the bearing plane 52a of the elastic bearing member 52. Fig. 22 , Fig. 22 This is a structural diagram of another watchband 30 provided in an embodiment of the present application. The circuit board body 51 of the flexible circuit board 50 can form a three-dimensional structure to improve the stretchability of the flexible circuit board 50. The flexible circuit board 50 includes a circuit board body 51 and an elastic bearing member 52, and the structure and material of the circuit board body 51 and the elastic bearing member 52 are the same as those in the previous embodiment, so no repeated description is given.

[0145] Specifically, see Fig.23 , Fig.23 for Fig. 22The structure diagram of the flexible circuit board 50 in the strap 30 is provided. The first end of the circuit board body 51 points to the direction of the second end (that is, the first direction, Fig.23 The Y direction is the length direction of the elastic supporting member 52 . The circuit board body 51 is wound around the elastic supporting member 52 and extends along the length direction of the elastic supporting member 52 . The circuit board body 51 is fixedly connected to the elastic supporting member 52 .

[0146] For example, please refer to Fig.23 The elastic bearing member 52 may be a cylindrical structure, that is, the cross section of the elastic bearing member 52 along the first direction perpendicular to the first direction is a circular structure. The circuit board body 51 is wound around the elastic bearing member 52 and extends along the first direction, that is, the circuit board body 51 extends in a spiral manner along the first direction, and takes the axis of the elastic bearing member 52 as the center line, thereby forming a spring-like structure.

[0147] In this way, since the above-mentioned circuit board body 51 forms a spring-like structure, the circuit board body 51 has good stretchability along the first direction. When the strap 30 of the wearable device 01 is stretched, the elastic bearing member 52 is stretched synchronously, and the circuit board body 51 fixed on the elastic bearing member 52 is stretched along with the elastic bearing member 52. During the stretching process, the spring-like structure formed by the circuit board body 51 gradually separates along the first direction, that is, the circuit board body 51 is stretched, and the circuit board body 51 itself does not bear a large tensile force, thereby reducing the risk of the circuit board body 51 being broken and damaged. When the tensile force disappears, the elastic bearing member 52 is reset, and the circuit board body 51 is reset synchronously with the elastic bearing member 52.

[0148] It is understandable that the cross-sectional shape of the elastic bearing member 52 along the direction perpendicular to the first direction may be an ellipse, a regular polygon, etc. in addition to the circular structure mentioned above. Therefore, the present application does not make any special limitation on this.

[0149] In some examples, the circuit board body 51 may be fixed on the surface of the elastic bearing member 52. For example, the circuit board body 51 is fixedly connected to the elastic bearing member 52 by gluing, which is helpful to reduce the process difficulty and improve the production efficiency.

[0150] Also, see Fig.24 , Fig.24 This is a structural diagram of another elastic bearing member 52 provided in an embodiment of the present application. A receiving groove 52b may be provided on the surface of the elastic bearing member 52. The spiral direction of the receiving groove 52b is the same as the spiral direction of the circuit board body 51. The circuit board body 51 is disposed in the receiving groove 52b. Under this structure, the circuit board body 51 can be formed by electroplating metal material in the receiving groove 52b, which helps to reduce the process difficulty.

[0151] Alternatively, the circuit board body 51 may be embedded in the elastic bearing member 52 , which is beneficial to reducing the cross-sectional size of the flexible circuit board 50 on the one hand, and can also wrap the circuit board body 51 to effectively protect the circuit board body 51 on the other hand.

[0152] Based on this, the flexible circuit board 50 can be processed by the steps 1 to 3 in the above-mentioned manufacturing method, the only difference is that the circuit board body 51 is processed into a long strip structure, see Fig.25 and Fig.26 , Fig.25 The metal layer 512 on the circuit board substrate 70 provided in the embodiment of the present application is processed into a structure diagram of multiple metal circuits. Fig.26 for Fig.25 The provided circuit board substrate 70 forms a structural diagram of a circuit board body 51 having a plurality of parallel metal lines.

[0153] Then, the circuit board body 51 having a plurality of metal circuits is wound around a Fig.23 or Fig.24 The elastic supporting member 52 of the columnar structure shown in the figure is fixedly connected by gluing. Alternatively, the elastic supporting member 52 is heated so that the elastic supporting member 52 is adhered and fixed to the circuit board body 51 by its own adhesiveness. Thus, the circuit board body 51 forms a spring-like structure, that is, a structure as shown in FIG. Fig.23 The flexible circuit board 50 has a three-dimensional structure as shown.

[0154] After the flexible circuit board 50 is formed, a layer of elastic supporting member 52 material may be wrapped on the outside thereof and fixed so that the circuit board body 51 is embedded in the elastic supporting member 52 , thereby providing more effective protection for the circuit board body 51 .

[0155] In addition, the above-mentioned three-dimensional flexible circuit board 50 provided in the embodiment of the present application can also be manufactured by the following manufacturing method, which may include:

[0156] Step 1: Select a material with good elastic properties as the substrate 72. For example, the above-mentioned PDMS material, ecoflex material or hydrogel can be used. In addition, a dry film can be coated on the substrate 72, and through exposure, development, wet etching, stripping of the dry film and other processes, mutually parallel grooves 72a are formed on the surface of the substrate 72. Multiple grooves 72a are distributed along the above-mentioned first direction at intervals, and the extension direction of the grooves 72a forms an acute angle with the above-mentioned first direction. Please refer to Fig. 27 , Fig. 27 A structural diagram of a plurality of grooves 72a formed on a substrate 72 provided in an embodiment of the present application.

[0157] Exemplarily, the depth of the groove 72 a may be 12 μm, the width of the groove 72 a may be 60 μm, the interval between two adjacent grooves 72 a is 100 μm, and the angle formed by the groove 72 a and the first direction is 60°.

[0158] Step 2: Please refer to Fig.28 , Fig.28 for Fig. 27 The structural diagram of the substrate 72 provided is after being folded in half. The above-mentioned substrate 72 is folded in half into a cylindrical shape, so that the two edges extending along the first direction of the substrate 72 are in contact with each other, and the substrate 72 is heated to a semi-cured state, so that the two edges of the substrate 72 along the first direction are fixed by self-adhesion. At this time, the end of each groove body 72a forms a structure connected end to end with the end of another adjacent groove body 72a, so that multiple groove bodies 72a form a spiral groove 72b structure that spirally extends around the cylindrical substrate 72. And the interior of the cylindrical substrate 72 is filled with the same raw material as the substrate 72, so as to form a cylindrical elastic bearing member 52, please refer to Fig.29 , Fig.29 for Fig.28 A structural diagram of an elastic support member 52 formed of a cylindrical substrate 72 is provided. The diameter of the elastic support member 52 may be about 1 mm.

[0159] Step 3: Please refer to Fig.30 , Fig.30 for Fig.29 The cross-sectional structure diagram of the elastic bearing member 52 along its axial direction is provided. The seed layer 71 metal is sputtered on the inner wall of the spiral groove 72b, and a spring-like metal circuit of a three-dimensional structure is obtained by electroplating and etching, that is, the circuit board body 51, see Fig.31 , Fig.31 for Fig.30 The spiral groove 72b of the elastic bearing member 52 is provided to form a structural diagram of the circuit board body 51. The metal circuit surface is flush with the surface of the elastic bearing member 52. Exemplarily, the seed layer 71 material can be titanium copper with a thickness of 3μm, and the electroplated metal is copper with a thickness of 12μm.

[0160] In some embodiments, the spiral groove 72 b may also be filled with metal materials such as aluminum, nickel, silver paste, nano silver wire ink, etc. Therefore, the present application does not make any special limitation to this.

[0161] Step 4: Please refer to Fig.32 , Fig.32 for Fig.31The cross-sectional structure of the protective layer 513 and the shielding layer 514 along the radial direction is provided on the outer side of the flexible circuit board 50. A protective layer 513 is wrapped around the outer side of the elastic bearing member 52, and the material of the protective layer 513 can be the same as or different from that of the elastic bearing member 52. Then, the shielding layer 514 can be covered on the outer side of the protective layer 513 to enhance the electromagnetic shielding effect of the metal circuit. Thus, the above-mentioned flexible circuit board 50 is formed.

[0162] It should be noted that the materials of the protective layer 513 and the shielding layer 514 are the same as those in the previous embodiment. In addition, the process steps of connecting the flexible circuit with the functional module 40 and the connector 60, and the method of encapsulating the flexible circuit in the strap 30 are the same as those in the previous embodiment, so they are not described again here.

[0163] In addition, the three-dimensional flexible circuit board 50 provided in the embodiment of the present application can also be manufactured by the following manufacturing method:

[0164] Step 1: Please refer to Fig.33 , Fig.33 The structural diagram of the cylindrical elastic bearing member 52 provided in the embodiment of the present application is that a material with good elastic properties is selected to make the cylindrical elastic bearing member 52. For example, the above-mentioned PDMS material, ecoflex material or hydrogel can be used.

[0165] Step 2: Sputter a seed layer 71 of metal on the surface of the elastic bearing member 52, and then electroplate a metal layer 512 on the surface of the seed layer 71 by electroplating. For example, the seed layer 71 can be made of titanium copper with a thickness of 3 μm. The metal layer 512 formed by electroplating can be made of copper with a thickness of 12 μm. Alternatively, the metal layer 512 can also be made of metal materials such as aluminum, nickel, and silver paste. Fig.34 and Fig.35 , Fig.34 for Fig.33 The structure diagram of the metal layer 512 formed on the surface of the elastic bearing member 52 is provided, Fig.35 for Fig.34 A cross-sectional structural diagram along the radial direction of the elastic supporting member 52.

[0166] Step 3: Please refer to Fig.36 , Fig.36 for Fig.35 The metal layer 512 is provided as a schematic diagram of the structure of cutting. Laser ablation or femtosecond laser cutting is used. The laser source is fixed, and both ends of the cylindrical elastic bearing member 52 are fixed, rotated and oriented (for example, the first direction mentioned above, i.e. Fig.36The elastic supporting member 52 is moved in the Y direction, thereby cutting the metal layer 512 on the surface of the elastic supporting member 52 to form a metal circuit with a spiral structure similar to a spring, that is, to form the circuit board body 51.

[0167] Alternatively, see Fig.37 and Fig.38 , Fig.37 for Fig.34 The structure diagram of the spiral structure film layer formed on the surface of Fig.38 for Fig.37 A cross-sectional structure diagram along the axial direction of the elastic bearing member 52. A dry film is formed on the surface of the metal layer 512, and the dry film forms a spiral structure similar to a spring. Then, through the processes of aging, exposure, development, wet etching, and stripping of the dry film, the metal layer 512 on the surface of the elastic bearing member 52 forms a metal circuit with a spiral structure similar to a spring, that is, the circuit board body 51 is formed. Please refer to Fig.39 , Fig.39 For Fig.37 and Fig.38 A structural diagram of a circuit board body 51 is provided after a metal layer 512 having a spiral structure film layer is etched.

[0168] Exemplarily, the width w of the circuit board body 51 (ie, the metal circuit) is 60 μm, the spacing b of the spring-like structure is 100 μm, and the angle α formed between the oblique extension direction of the spring structure and the first direction is 60°.

[0169] Step 4: Wrap a protective layer 513 outside the elastic bearing member 52. The material of the protective layer 513 can be the same as or different from that of the elastic bearing member 52. Then, a shielding layer 514 can be covered outside the protective layer 513 to enhance the electromagnetic shielding effect of the metal circuit. Fig.32 The flexible circuit board 50 is shown.

[0170] It should be noted that the materials of the protective layer 513 and the shielding layer 514 are the same as those in the previous embodiment. In addition, the process steps of connecting the flexible circuit with the functional module 40 and the connector 60, and the method of encapsulating the flexible circuit in the strap 30 are the same as those in the previous embodiment, so they are not described again here.

[0171] In addition, the spring-like spiral structure metal layer 512 provided in the above embodiment can form the circuit board body 51. Alternatively, the circuit board body 51 formed by the metal layer 512 and the dielectric layer 511 can be wound on the elastic bearing member 52 to form the flexible circuit board 50. Therefore, the present application does not make any special limitation on this.

[0172] In summary, the above-mentioned flexible circuit boards 50 provided in the embodiments of the present application all use materials with good elastic properties as the elastic bearing member 52. Then, the circuit board body 51 that is bent and extended, and the circuit board body 51 with a through slot 51a are fitted and fixed on the bearing plane 52a of the elastic bearing member 52; or, the circuit board body 51 is wound in a winding direction and fixed on the elastic bearing member 52 of a columnar structure.

[0173] On the one hand, the stretchability of the circuit board body 51 is improved by extending the circuit board body 51 itself, that is, when the circuit board body 51 is stretched along one direction (for example, the first direction mentioned above), only the structural form or shape of the circuit board body 51 can be changed, and the circuit board body 51 itself does not bear a large tensile force, which is beneficial to reduce the risk of the circuit board body 51 being broken and damaged.

[0174] On the other hand, the circuit board body 51 is fixed on the elastic bearing member 52, and the elastic performance of the elastic bearing member 52 itself can drive the circuit board body 51 to stretch and reset. Therefore, when the strap 30 of the wearable device 01 is not in a stretched state, it can ensure that the circuit board body 51 is reset, that is, the circuit board body 51 is not in a stretched state, which is conducive to forming a more effective protection for the circuit board body 51, so as to further reduce the risk of damage to the circuit board body 51.

[0175] Therefore, when the flexible circuit board 50 provided in the embodiment of the present application is used in the strap 30 of the wearable device 01, it is beneficial to improve the reliability of the electrical connection between the functional module 40 and the main board 20, and can effectively reduce the risk of failure of the functional module 40 during use by the user, thereby helping to improve the user experience.

[0176] In the description of this specification, specific features, structures, materials or characteristics may be combined in an appropriate manner in any one or more embodiments or examples.

[0177] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A watch strap for a wearable device, characterized in that: The watch strap comprises a watch strap body, a functional module and a flexible circuit board, wherein the functional module is arranged on the watch strap body, the flexible circuit board is embedded in the watch strap body, and the flexible circuit board comprises: A circuit board body, wherein the circuit board body has a first end and a second end, the first end of the circuit board body is used to be electrically connected to the functional module, and the second end of the circuit board body is used to be electrically connected to the mainboard of the wearable device; An elastic bearing member, the direction from the first end to the second end is the length direction of the elastic bearing member, and the direction from the first end to the second end is the length direction of the strap; the circuit board body is wound around the elastic bearing member and extends in a spiral manner along the length direction of the elastic bearing member to form a spring-like structure, and the circuit board body is fixedly connected to the elastic bearing member; When the watchband is stretched, the elastic bearing member is stretched synchronously, and the circuit board body is stretched along with the elastic bearing member.

2. The watch strap according to claim 1, characterized in that: The circuit board body is attached to and fixed on the surface of the elastic bearing component.

3. The watch strap according to claim 2, characterized in that: A receiving groove is formed on the surface of the elastic bearing member. The extending direction of the receiving groove is the same as the extending direction of the circuit board body. The circuit board body is arranged in the receiving groove.

4. The watch strap according to claim 1, characterized in that: The circuit board body is embedded in the elastic bearing component.

5. The watch strap according to any one of claims 1 to 4, characterized in that: The cross section of the elastic bearing member along the direction perpendicular to the length is circular, regular polygonal or elliptical.

6. The watch strap according to claim 5, characterized in that: The cross section of the elastic bearing member along the direction perpendicular to the length is circular.

7. The watch strap according to any one of claims 1 to 6, characterized in that: The functional modules include sensors, display modules, camera modules, solar charging modules or pulse modules.

8. A wearable device, characterized in that: include: dial; A main board, arranged in the dial; The watch strap is the watch strap according to any one of claims 1 to 7, wherein the watch strap is connected to the watch dial, and the flexible circuit board is electrically connected to the main board.

Images