Flexible stretchable circuit and method of making the same, electronic device

Abstract

The application relates to a flexible stretchable circuit and a preparation method thereof and electronic equipment. The flexible stretchable circuit comprises a flexible stretchable substrate, a wire unit, a plurality of components and a packaging body. The wire unit comprises a middle wire, a positive wire and a negative wire connected with the middle wire. The middle wire comprises a plurality of first wires and second wires arranged in a snake shape. The first wires and the second wires are crossed and connected to enclose a plurality of array-distributed blank areas. The first wires are intermittently connected to form a connection area. The components correspond to the connection area one by one and are connected with the first wires. The packaging body is arranged on the flexible stretchable substrate, and the wire unit and the components are covered in the packaging body. When the circuit is stretched, the first wires and / or the second wires are stretched and deformed to have a longer wire length, but the cross-sectional area does not change, so that the circuit resistance value can remain stable, and the normal work of the components of the small-size circuit can be realized when the circuit is bent and stretched.

Description

Technical Field

[0001] This application relates to the field of flexible electronics technology, and in particular to a flexible stretchable circuit and its fabrication method, as well as electronic devices. Background Technology

[0002] With the continuous advancement of technology, people are paying more and more attention to health. In addition to traditional medical models such as treatment in hospitals, emerging health care models such as home physiotherapy are gradually developing, leading to higher and more diversified requirements for wearable physiotherapy products for the home. LED phototherapy products are an important category of wearable physiotherapy products for the home. As the medical principles and indications of phototherapy are continuously discovered, these products are gradually developing towards intelligence, miniaturization, and flexibility.

[0003] In the manufacturing process of LED wearable phototherapy products, flexible and stretchable circuits are the most important technical component and a crucial technical problem that urgently needs to be solved to achieve product miniaturization and flexibility. Currently, flexible wearable circuits mainly use FPC circuit boards, which can achieve flexible bending within a large size range, but it is difficult to achieve stretchability, and their bending recovery ability is poor when the product size is small. Novel flexible circuit fabrication methods, such as 3D printing and inkjet printing, use conductive silver paste, liquid metal, etc. as conductive materials to achieve circuit bending and stretching, but their conductivity is poor, and it is difficult to achieve good conductivity due to material limitations. Moreover, the resistance increases significantly during stretching, affecting the normal operation of components. Summary of the Invention

[0004] In order to achieve stable resistance of small-sized circuits when bent and stretched, this application provides a flexible stretchable circuit, its fabrication method, and an electronic device.

[0005] This application provides a flexible and stretchable circuit, its fabrication method, and an electronic device, which adopts the following technical solution:

[0006] In a first aspect, a flexible and stretchable circuit includes:

[0007] Flexible stretchable substrate;

[0008] A conductor unit includes an intermediate conductor, positive conductors and negative conductors connected to the intermediate conductor, the intermediate conductor includes a plurality of first conductors arranged in a serpentine pattern and a plurality of second conductors arranged in a serpentine pattern, the plurality of first conductors extending along a first direction and spaced apart in a second direction, the plurality of second conductors extending along a second direction and spaced apart in the first direction, the first conductors and second conductors intersecting and connecting to form a plurality of arrayed blank areas, the plurality of first conductors intermittently forming first connection points and second connection points, and the area between the first connection points and the second connection points is a connection area;

[0009] Multiple components, each corresponding one-to-one with the connection area, wherein the positive and negative terminals of each component correspond one-to-one with and are connected to the first connection point and the second connection point; and,

[0010] An encapsulation body is disposed on the flexible and stretchable substrate, and the wire unit and each of the components are encapsulated within the encapsulation body. The encapsulation body is made of a flexible and stretchable material.

[0011] By adopting the above technical solution, the first and second conductors are set in a serpentine shape. The local small deformation of the first and second conductors can obtain a large cumulative deformation, which can realize the flexible bending and stretching of the circuit within a small size range. When stretched, the first and / or second conductors are stretched and deformed to have a longer trace length, but the cross-sectional area does not change, so that the circuit resistance value can remain stable, and stable light emission of small-sized circuits can be achieved when bending and stretching.

[0012] The first conductor intermittently forms a connection area with the component, while the second conductor remains continuous. This allows the stretching deformation to be quickly transmitted to all parts of the second conductor when the circuit is stretched in the second direction. Furthermore, the stretching deformation in the second direction reduces the pulling on the connection point between the first conductor and the component, thereby reducing the probability of circuit damage.

[0013] Preferably, the ends of each of the first wires are bent in a direction away from the flexible stretchable substrate to form a bent portion, and then bent in a direction parallel to the flexible stretchable substrate to form a support portion, and the component is connected to the support portion.

[0014] By adopting the above technical solution, the bending portion is wrapped by the encapsulation layer, which improves the support capacity of the support portion for components and facilitates the soldering of components to the support portion. The width or cross-sectional area of ​​the first conductive portion, which is attached to the flexible and stretchable substrate, can be set according to the required resistance value of the circuit, without needing to consider whether it is easy to solder to the components. By providing the bending portion, the pulling force on the connection point between the support portion and the components can be reduced when the circuit is stretched and deformed in the first direction, thereby reducing the probability of circuit damage.

[0015] Preferably, the first conductors between each pair of adjacent second conductors form a connection region intermittently.

[0016] By adopting the above technical solution, the number of components that can be installed can be increased.

[0017] Preferably, the component is an LED chip.

[0018] By adopting the above technical solution, the LED chip can emit visible light of a certain wavelength, thus achieving a therapeutic effect; a connection area is intermittently formed between each pair of adjacent second conductors. This allows for an increase in the number of LEDs installed, increasing the light output power and improving the therapeutic effect.

[0019] Preferably, the cross-sectional areas of the first conductor and the second conductor gradually increase from the middle to both ends.

[0020] By adopting the above technical solution, the smaller the cross-sectional area of ​​the first conductor and the second conductor, the easier they are to deform. This makes the middle part of the first conductor and the second conductor easier to deform than the end part, so as to balance the amount of tensile deformation of each part of the first conductor and the second conductor and make the components evenly distributed. The components are LED chips, which realize uniform light output and avoid excessively strong or weak local light output intensity after the circuit is stretched.

[0021] Preferably, both the positive and negative conductors are serpentine and extend along the first direction, the positive conductor, the intermediate conductor, and the negative conductor are spaced apart in the second direction, and a plurality of second conductors are alternately connected to the positive conductor and the negative conductor.

[0022] By adopting the above technical solution, each component is located between two adjacent second wires, ensuring that both the positive and negative terminals of each component are connected to the second wires. In each pair of adjacent second wires, one wire is connected to the positive wire, and the other is connected to the negative wire. This allows each component to be directly connected to both the positive and negative wires, enabling parallel connection between components without interference and preventing damage to one component from affecting the operation of others. When the component is an LED chip, checking whether each LED chip is emitting light normally facilitates rapid troubleshooting of circuit faults.

[0023] Preferably, the cross-sectional areas of the positive electrode wire and the negative electrode wire gradually increase from the middle to both ends.

[0024] By adopting the above technical solution, the smaller the cross-sectional area of ​​the positive and negative conductors, the easier they are to deform. This makes the middle of the positive and negative conductors more prone to deformation than their ends, thus balancing the amount of stretching deformation in different parts of the flexible and stretchable substrate as much as possible. This results in more uniform stretching at the connection points between each component and the conductor unit, preventing excessive deformation of any component and its potential damage. Simultaneously, it ensures uniform distribution of components (LED chips), achieving uniform light output and preventing excessively strong or weak local light intensity after circuit stretching.

[0025] Preferably, the conductor unit is integrally formed.

[0026] By adopting the above technical solution, the conductive plate is cut to facilitate the processing and production of the wire unit, ensuring the integrity of the entire wire unit and thus ensuring the conductivity of each position of the wire unit. It is possible to produce wire units with the same width or cross-sectional area for each part, and the width or cross-sectional area of ​​each part of the wire unit can also be controlled according to actual needs.

[0027] Secondly, this application also provides a method for fabricating a flexible and stretchable circuit, comprising the following steps:

[0028] S1: Fabricate a wire unit, the wire unit comprising an intermediate wire, positive wires and negative wires all connected to the intermediate wire, the intermediate wire comprising a plurality of first wires arranged in a serpentine pattern and a plurality of second wires arranged in a serpentine pattern, the plurality of first wires extending along a first direction and spaced apart in a second direction, the plurality of second wires extending along the second direction and spaced apart in the first direction, the first wires and second wires intersecting and connecting to form a plurality of arrayed blank areas, the plurality of first wires intermittently forming first connection points and second connection points, the area between the first connection points and the second connection points being a connection region; and...

[0029] S2: Provide a flexible and stretchable substrate, adhere the wire unit to the flexible and stretchable substrate; mount each component to each of the connection areas, and weld the positive and negative terminals of the components to the first connection point and the second connection point respectively; encapsulate the wire unit and the components using a flexible and stretchable material to form an encapsulation body located on the flexible and stretchable substrate and covering the wire unit and the components.

[0030] By adopting the above technical solution, the first and second conductors are set in a serpentine shape. The local small deformation of the first and second conductors can obtain a large cumulative deformation, which can realize the flexible bending and stretching of the circuit within a small size range. When stretched, the first and / or second conductors are stretched and deformed to have a longer trace length, but the cross-sectional area does not change, so that the circuit resistance value can remain stable, and stable light emission of small-sized circuits can be achieved when bending and stretching.

[0031] The first conductor intermittently forms a connection area with the component, while the second conductor remains continuous. This allows the stretching deformation to be quickly transmitted to all parts of the second conductor when the circuit is stretched in the second direction. Furthermore, the stretching deformation in the second direction reduces the pulling on the connection point between the first conductor and the component, thereby reducing the probability of circuit damage.

[0032] Preferably, in step S1, the step of preparing the wire unit is as follows: providing a conductive plate, and cutting the conductive plate according to a preset pattern to form the wire unit.

[0033] By adopting the above technical solution, the conductive plate is cut to facilitate the processing and production of the wire unit, ensuring the integrity of the entire wire unit and thus ensuring the conductivity of each position of the wire unit. It is possible to produce wire units with the same width or cross-sectional area for each part, and the width or cross-sectional area of ​​each part of the wire unit can also be controlled according to actual needs.

[0034] Preferably, in step S1, the conductive plate is cut so that the first connection point and the second connection point extend in opposite directions to form extension pieces, the extension pieces are bent in a direction away from the flexible stretchable substrate to form a bent portion, and then bent in a direction parallel to the flexible stretchable substrate to form a support portion.

[0035] In step S2, after the wire unit is adhered to the flexible stretchable substrate, the bent portion is encapsulated to form a first encapsulation layer located on the flexible stretchable substrate, covering the bent portion and exposing the support portion; the component is mounted on the support portion, and the component and the support portion are soldered; the support portion and the component are encapsulated to form a second encapsulation layer located on the first encapsulation layer.

[0036] By adopting the above technical solution, the bending portion is wrapped by the first encapsulation layer, which improves the support capacity of the support portion for components and facilitates the soldering of components to the support portion. The width or cross-sectional area of ​​the first conductive portion, which connects the component to the support portion and adheres to the flexible stretchable substrate, can be set according to the required resistance value of the circuit, without needing to consider whether it is easy to solder to the component. By providing the bending portion, the pulling force on the connection point between the support portion and the component can be reduced when the circuit is stretched and deformed in the first direction, thereby reducing the probability of circuit damage.

[0037] Preferably, in step S1, the conductive plate is cut so that both the positive electrode wire and the negative electrode wire are serpentine and extend along the first direction, the positive electrode wire, the intermediate wire and the negative electrode wire are spaced apart in the second direction, and a plurality of second wires are alternately connected to the positive electrode wire and the negative electrode wire.

[0038] By adopting the above technical solution, each component is located between two adjacent second wires, ensuring that both the positive and negative terminals of each component are connected to the second wires. In each pair of adjacent second wires, one wire is connected to the positive wire, and the other is connected to the negative wire. This allows each component to be directly connected to both the positive and negative wires, enabling parallel connection between components without interference and preventing damage to one component from affecting the operation of others. When the component is an LED chip, checking whether each component is emitting light normally facilitates rapid troubleshooting of circuit faults.

[0039] Thirdly, this application also provides an electronic device including the flexible stretchable circuit as described in any of the preceding claims.

[0040] By adopting the above technical solution, the first and second conductors are set in a serpentine shape. The local small deformation of the first and second conductors can obtain a large cumulative deformation, which can realize the flexible bending and stretching of the circuit within a small size range. When stretched, the first and / or second conductors are stretched and deformed to have a longer trace length, but the cross-sectional area does not change, so that the circuit resistance value can remain stable, and stable light emission of small-sized circuits can be achieved when bending and stretching.

[0041] In summary, this application includes at least one of the following beneficial technical effects:

[0042] 1. By setting the first and second conductors to a serpentine shape, a large cumulative deformation can be obtained through the local small deformation of the first and second conductors, which can realize the flexible bending and stretching of the circuit within a small size range. When stretched, the first conductor and / or the second conductor are stretched and deformed to have a longer trace length, but the cross-sectional area does not change, so that the circuit resistance value can remain stable, and stable light emission can be achieved when the small-sized circuit is bent and stretched.

[0043] 2. The first conductor is discontinuously connected to the component, while the second conductor remains continuous. This allows the stretching deformation to be quickly transmitted to all parts of the second conductor when the circuit is stretched in the second direction. Furthermore, the stretching deformation in the second direction reduces the pulling on the connection point between the first conductor and the component, thereby reducing the probability of circuit damage.

[0044] 3. The component is an LED chip, which emits visible light of a certain wavelength to achieve a therapeutic effect; the first wire between each two adjacent second wires forms a discontinuous connection area. This allows for an increase in the number of LEDs installed, increasing the light output power and improving the therapeutic effect. Attached Figure Description

[0045] Figure 1 This is a top view of the flexible and stretchable circuit (with components and package hidden) in Embodiment 1 of this application;

[0046] Figure 2 This is a top view of the flexible and stretchable circuit (hidden package) in Embodiment 1 of this application;

[0047] Figure 3 This is a cross-sectional structural schematic diagram of the flexible and stretchable circuit in Embodiment 1 of this application;

[0048] Figure 4 yes Figure 3A magnified view of a portion of point A in the middle;

[0049] Figure 5 This is a cross-sectional structural diagram of the flexible and stretchable circuit in Embodiment 2 of this application;

[0050] Figure 6 This is a cross-sectional structural diagram of the flexible and stretchable circuit in Embodiment 3 of this application;

[0051] Figure 7 This is a cross-sectional structural diagram of the flexible and stretchable circuit in Embodiment 5 of this application;

[0052] Figure 8 yes Figure 7 A magnified view of a portion of point B in the middle;

[0053] Figure 9 This is a schematic diagram of the wire unit in Embodiment 6 of this application;

[0054] Figure 10 yes Figure 9 A magnified view of a portion of point C in the middle;

[0055] Figure 11 This is a cross-sectional structural diagram of the flexible and stretchable circuit in Embodiment 8 of this application.

[0056] Explanation of reference numerals in the attached drawings: 1. Flexible and stretchable substrate; 2. Conductor unit; 21. Intermediate conductor; 211. First conductor; 211a. First connection point; 211b. Second connection point; 212. Second conductor; 213. Blank area; 214. Connection area; 215. Bending part; 216. Support part; 217. Extension sheet; 22. Positive conductor; 23. Negative conductor; 3. Component; 4. Package; 41. First encapsulation layer; 42. Second encapsulation layer; 5. Fabric; 51. Hardened area. Detailed Implementation

[0057] The following is in conjunction with the appendix Figure 1-10 This application will be described in further detail.

[0058] This application provides a flexible and stretchable circuit and an electronic device. The electronic device includes the flexible and stretchable circuit and can be worn on the fingers and wrists for treating arthritis, etc.; worn on the abdomen for treating stretch marks, etc.; worn on the neck for treating neck wrinkles, etc. The electronic device can also be other devices that require bending and stretching, and there are no limitations on this. The innovation of this application lies in the flexible and stretchable circuit, which is described in detail below.

[0059] Example 1

[0060] This embodiment discloses a flexible stretchable circuit, which includes a flexible stretchable substrate 1, a wire unit 2, multiple components 3, and a package 4.

[0061] Reference Figure 1 The flexible and stretchable substrate 1 is a sheet structure, which can be rectangular, square or other shapes. It is made of an elastic polymer material and has the properties of being flexible, stretchable and non-conductive. The polymer material can be, but is not limited to, polydimethylsiloxane PDMS, polyurethane PU, thermoplastic polyurethane TPU, thermoplastic vulcanized rubber TPV, silicone, etc.

[0062] The conductor unit 2 includes an intermediate conductor 21, a positive conductor 22, and a negative conductor 23, all connected to the intermediate conductor 21. The positive conductor 22 and the intermediate conductor 21 can have one or more connection points; the positive conductor 22 is used to connect to the positive terminal of other circuits. The negative conductor 23 and the intermediate conductor 21 can also have one or more connection points; the negative conductor 23 is used to connect to the negative terminal of other circuits, thereby enabling circuit conduction.

[0063] Since electronic devices are generally used at room temperature, the material of the wire unit 2 can be a solid material that is conductive at room temperature, such as metal or flexible graphite. Metals can be, but are not limited to, gold, silver, aluminum, and copper. In this embodiment, the wire unit 2 is integrally formed. A single conductive plate is cut according to the required shape of the wire unit 2 to obtain an integrally formed wire unit 2. This facilitates the processing and production of the wire unit 2, ensuring the integrity of the entire wire unit 2 and thus guaranteeing the conductivity of each position of the wire unit 2. Simultaneously, wire units 2 with the same width or cross-sectional area in each part can be produced, or the width or cross-sectional area of ​​each part of the wire unit 2 can be controlled according to actual needs.

[0064] In this embodiment, the material of the wire unit 2 is copper sheet. Copper sheet has good conductivity and low price, which can reduce production costs. Copper sheet has poor hardness, which makes it easy to cut.

[0065] The intermediate conductor 21 includes a plurality of first conductors 211 arranged in a serpentine pattern and a plurality of second conductors 212 arranged in a serpentine pattern. The plurality of first conductors 211 extend along a first direction and are spaced apart in a second direction. The plurality of second conductors 212 extend along a second direction and are spaced apart in a first direction. The first conductors 211 and the second conductors 212 intersect and connect to form a plurality of array-distributed blank areas 213.

[0066] Reference Figure 1 Multiple first conductors 211 intermittently form first connection points 211a and second connection points 211b, and the area between the first connection points 211a and second connection points 211b is a connection region 214. (Refer to...) Figure 2Component 3 corresponds one-to-one with connection area 214. The positive and negative terminals of component 3 correspond one-to-one with first connection point 211a and second connection point 211b and are connected. In an optional embodiment, the first connection point 211a and the second connection point 211b can be arranged in a square shape to facilitate connection with component 3.

[0067] Reference Figure 3 and Figure 4 The package 4 is disposed on the flexible and stretchable substrate 1. The wire unit 2 and various components 3 are encapsulated within the package 4. The wire unit 2 can be connected to other circuits before being encapsulated within the package 4. The package 4 is made of a flexible and stretchable material, which is an elastic polymer material. It has the properties of being flexible, stretchable, and non-conductive. The polymer material can be, but is not limited to, polydimethylsiloxane (PDMS), polyurethane (PU), thermoplastic polyurethane (TPU), thermoplastic vulcanizate (TPV), silicone, etc. In this embodiment, both the flexible and stretchable substrate 1 and the package 4 are made of polydimethylsiloxane (PDMS).

[0068] By configuring the first conductor 211 and the second conductor 212 in a serpentine shape and stretching the flexible stretchable substrate 1 in a first or second direction, a large cumulative deformation can be achieved through the localized minute deformation of the first conductor 211 or the second conductor 212, enabling the circuit to be flexibly bent and stretched within a small size range. During stretching, the first conductor 211 and / or the second conductor 212 are stretched and deformed to have a longer trace length, but the cross-sectional area does not change, so that the circuit resistance value can remain stable, enabling the components of the small-sized circuit to operate normally during bending and stretching.

[0069] The first conductor 211 intermittently forms a connection area 214 that connects to the component 3, while the second conductor 212 remains continuous. This allows the stretching deformation to be quickly transmitted to various parts of the second conductor 212 when the circuit is stretched in the second direction. Furthermore, the stretching deformation in the second direction reduces the pulling on the connection point between the first conductor 211 and the component 3, thereby reducing the probability of circuit damage.

[0070] The angle between the first direction and the second direction can be an acute angle or a right angle. In this embodiment, the first direction and the second direction are perpendicular. When stretching the circuit in the second direction, the stretching amount of the first wire 211 can be reduced, thus reducing the impact on the connection of the component 3.

[0071] Reference Figure 2The first wire 211 between each pair of adjacent second wires 212 can be interrupted at multiple points, connecting multiple components 3; or it can be continuous and not connected to any component 3. In this embodiment, the first wire 211 between each pair of adjacent second wires 212 is interrupted to form a connection area 214, and each connection area 214 is connected to a component 3, which can increase the number of components 3 installed. The component 3 can be any component 3. In this embodiment, the component 3 is an LED chip. The LED chip can emit visible light of a certain wavelength, which plays a therapeutic role. Increasing the number of LED chips can increase the light output power and improve the therapeutic effect of the electronic device.

[0072] Example 2

[0073] Reference Figure 5 The difference between Embodiment 2 and Embodiment 1 is that the positive electrode wire 22 and the negative electrode wire 23 are both serpentine and extend along the first direction, the positive electrode wire 22, the intermediate wire 21 and the negative electrode wire 23 are alternately spaced in the second direction, and a plurality of second wires 212 are alternately connected to the positive electrode wire 22 and the negative electrode wire 23.

[0074] Each component 3 is located between two adjacent second wires 212, ensuring that both the positive and negative terminals of each component 3 are connected to the second wires 212. In each pair of adjacent second wires 212, one second wire 212 is connected to the positive wire 22, and the other second wire 212 is connected to the negative wire 23. This allows each component 3 to be directly connected to both the positive and negative wires 22 and 23, ensuring that the components 3 are connected in parallel without affecting each other. This prevents damage to one component 3 from impacting the normal operation of other components 3. Component 3 is an LED chip; checking whether each LED chip is emitting light normally facilitates quick troubleshooting of circuit faults.

[0075] Example 3

[0076] Reference Figure 6 The difference between Embodiment 3 and Embodiment 2 is that the angle between the first direction and the second direction is an acute angle. When the circuit is stretched in either the second direction or the first direction, the first conductor 211 and the second conductor 212 can be stretched and deformed simultaneously, increasing the area of ​​the circuit and thus increasing the treatment area. When stretching the circuit requires an increase in the width of the circuit in both the first and second directions, setting the angle between the first and second directions to an acute angle simplifies the stretching operation and allows for stretching of the circuit in both directions simultaneously.

[0077] Example 4

[0078] The difference between Example 4 and Example 2 is that the cross-sectional areas of the positive electrode wire 22, negative electrode wire 23, first wire 211, and second wire 212 gradually increase from the middle to both ends. It is understood that the smaller the cross-sectional area of ​​the positive electrode wire 22, negative electrode wire 23, first wire 211, and second wire 212, the easier they are to deform. This makes the middle of the positive electrode wire 22, negative electrode wire 23, first wire 211, and second wire 212 more prone to deformation than the ends. This helps to balance the tensile deformation of each part of the positive electrode wire 22, negative electrode wire 23, first wire 211, and second wire 212, ensuring more uniform tension at the connection points between each component 3 and the wire unit 2, and preventing excessive deformation of any one component 3 that could easily lead to damage. Simultaneously, the even distribution of the components 3 (LED chips) ensures uniform light output, preventing excessively strong or weak local light intensity after circuit stretching.

[0079] Example 5

[0080] Reference Figure 7 and Figure 8 The difference between Embodiment 5 and Embodiment 2 is that the discontinuous ends of each first conductor 211 are bent in a direction away from the flexible stretchable substrate 1 to form a bent portion 215, and then bent in a direction parallel to the flexible stretchable substrate to form a support portion 216. The component 3 is connected to the support portion 216. The bent portion 215 is wrapped by the encapsulation body 4, which can improve the support capacity of the support portion 216 for the component 3 and facilitate the soldering of the component 3 to the support portion 216. The width or cross-sectional area of ​​the portion of the first conductor 211 attached to the flexible stretchable substrate 1 can be set according to the required resistance value of the circuit, without considering whether it is easy to solder to the component 3. By setting the bent portion 215, when the circuit is stretched and deformed in the first direction, the pulling on the connection point between the support portion 216 and the component 3 can be reduced, thereby reducing the probability of circuit damage.

[0081] Example 6

[0082] Reference Figure 9 and Figure 10 The difference between Embodiment 6 and Embodiment 2 is that a fabric 5 is fixed to the side of the flexible stretchable substrate 1 facing away from the conductor unit 2. The positions of the fabric 5 corresponding to the bending portion 215 and the support portion 216 are hardened regions 51. The fabric 5 can be hardened by dripping curing adhesive or other methods. When stretching the circuit, the hardened region 51 of the fabric 5 has no elasticity, so the portion of the flexible stretchable substrate 1 corresponding to the hardened region 51 of the fabric 5 cannot be stretched. This reduces the pulling on the bending portion 215 and the support portion 216, thus preventing the connection between the component 3 and the conductor unit 2 from being affected by stretching, thereby reducing the probability of circuit damage. At the same time, the fabric 5 enhances the structural strength of the entire circuit, and the elasticity of the fabric 5 helps the entire circuit to rebound after stretching.

[0083] Example 7

[0084] This embodiment provides a method for fabricating a flexible and stretchable circuit, including the following steps:

[0085] S1: Prepare a wire unit 2. The wire unit 2 includes an intermediate wire 21, a positive wire 22 and a negative wire 23, all connected to the intermediate wire 21. The intermediate wire 21 includes a plurality of first wires 211 arranged in a serpentine pattern and a plurality of second wires 212 arranged in a serpentine pattern. The plurality of first wires 211 extend along a first direction and are spaced apart in a second direction. The plurality of second wires 212 extend along the second direction and are spaced apart in the first direction. The first wires 211 and the second wires 212 intersect and connect to form a plurality of arrayed blank areas 213. At least one first wire 211 intermittently forms a first connection point 211a and a second connection point 211b. The area between the first connection point 211a and the second connection point 211b is a connection area 214.

[0086] In an optional embodiment, the conductor unit 2 can be fabricated by bending and welding multiple conductive wires. In this embodiment, the steps for fabricating the conductor unit 2 are as follows: providing a conductive plate, and cutting the conductive plate according to a preset pattern, i.e., the pattern of the conductor unit 2, to form the conductor unit 2. The conductor unit 2 formed by cutting the conductive plate is integrally molded. The conductive plate is made of a conductive solid material, such as metal or flexible graphite; the metal can be, but is not limited to, gold, silver, aluminum, and copper. In this embodiment, the conductive plate is a copper sheet with a thickness of 70 micrometers, and the copper sheet is cut into the designed conductor unit 2 pattern using a laser.

[0087] The width and thickness of each part of the conductor unit 2 can be controlled by cutting. If the thickness of the conductive plate is uniform, the cross-sectional area of ​​each part can be controlled by controlling the width of each part of the conductor unit 2.

[0088] The wire unit 2 can have various patterns. In one optional embodiment, both the positive wire 22 and the negative wire 23 are serpentine and extend along a first direction. The positive wire 22, the intermediate wire 21, and the negative wire 23 are spaced apart sequentially in a second direction. A plurality of second wires 212 are alternately connected to the positive wire 22 and the negative wire 23. The angle between the first wire 211 and the second wire 212 can be an acute angle or a right angle.

[0089] S2: Provides a flexible and stretchable substrate 1, which is a sheet structure made of an elastic polymer material. It has the properties of being flexible, stretchable, and non-conductive. The polymer material can be, but is not limited to, polydimethylsiloxane (PDMS), polyurethane (PU), thermoplastic polyurethane (TPU), thermoplastic vulcanizate (TPV), silicone, etc.

[0090] In this embodiment, a PDMS premixed liquid with a volume ratio of 20:1 was mixed with a curing liquid and mechanically stirred at a speed of 800 r / min for 10 min. After stirring until homogeneous, the PDMS was degassed under vacuum. The degassed PDMS was then cast into a film using a casting method to prepare a PDMS substrate with a thickness of 2 mm on the substrate. The prepared PDMS substrate was then placed in a forced-air drying oven for curing at a temperature of 95°C for 180 min.

[0091] The wire unit 2 is adhered to the flexible stretchable substrate 1. Specifically, the fabricated wire unit 2 is placed on a clean table, and the PDMS substrate is placed upside down on the wire unit 2. The adhesiveness of the PDMS surface can firmly adhere the entire wire unit 2 to its surface.

[0092] Each component 3 is mounted on its respective connection area 214, and the positive and negative terminals of the component 3 are aligned with the first connection point 211a and the second connection point 211b and soldered accordingly. Specifically, the component 3 is an LED chip. The PDMS substrate with the wire unit 2 attached is placed, and the LED chip is attached to the connection area 214 of the wire unit 2 using a pick-and-place machine. Then, reflow soldering is used to firmly solder the LED chip onto the wire unit 2.

[0093] Flexible and stretchable material is used to encapsulate the wire unit 2 and component 3, forming an encapsulation body 4 located on the flexible and stretchable substrate 1 and covering the wire unit 2 and component 3. The soldered circuit is transferred to a vacuum plasma cleaner to clean the PDMS and circuit surface; the cleaned circuit is placed in a mold and encapsulated with silicone with a thickness of 5mm.

[0094] The method for fabricating the flexible and stretchable circuit provided in this embodiment can be used to fabricate the flexible and stretchable circuits provided in embodiments 1-4 above.

[0095] Example 8

[0096] Reference Figure 11 The difference between Embodiment 8 and Embodiment 7 is that in step S1, the conductive plate is cut so that the first connection point 211a and the second connection point 211b extend in opposite directions to form an extension piece 217. The extension piece 217 is bent in a direction away from the flexible stretchable substrate 1 to form a bent portion 215, and then bent in a direction parallel to the flexible stretchable substrate to form a support portion 216.

[0097] In step S2, after the wire unit 2 is adhered to the flexible stretchable substrate 1, the bent portion 215 is encapsulated to form a first encapsulation layer 41 located on the flexible stretchable substrate 1, covering the bent portion 215 and exposing the support portion 216; the component 3 is mounted on the support portion 216, and the component 3 and the support portion 216 are soldered; the support portion 216 and the component 3 are encapsulated to form a second encapsulation layer 42 located on the second encapsulation layer 42 (refer to...). Figure 8 ).

[0098] The bent portion 215 is encapsulated by the first encapsulation layer 41, which improves the support capacity of the support portion 216 for the component 3 and facilitates the soldering of the component 3 to the support portion 216. The width or cross-sectional area of ​​the first conductive line 211 portion, which is attached to the flexible stretchable substrate 1 and connected to the support portion 216, can be set according to the required resistance value of the circuit, without needing to consider whether it is easy to solder to the component 3. By providing the bent portion 215, the pulling force on the connection point between the support portion 216 and the component 3 can be reduced when the circuit is stretched and deformed in the first direction, thereby reducing the probability of circuit damage.

[0099] The method for fabricating the flexible and stretchable circuit provided in this embodiment can be used to fabricate the flexible and stretchable circuit provided in Embodiment 5 above.

[0100] Example 9

[0101] The difference between Example 9 and Example 7 is that in step S2, the PDMS premixed liquid and the curing liquid with a volume ratio of 10:1 are mixed and mechanically stirred at a stirring speed of 500 r / min for 15 min. After stirring evenly, the bubbles are removed under vacuum. The degassed PDMS is then spin-coated onto the substrate using a spin coater to form a PDMS substrate with a thickness of 0.2 mm. The spin-coated PDMS, including the substrate, is then placed in a forced-air drying oven for curing at a curing temperature of 105°C for 30 min. Finally, the PDMS is used for encapsulation, with an encapsulation thickness of 3 mm.

[0102] The above are all preferred embodiments of this application and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A flexible stretchable circuit, characterized in that, The application relates to a flexible stretchable substrate (1), a wire unit (2) comprising a middle wire (21), a positive wire (22) and a negative wire (23) connected with the middle wire (21), the middle wire (21) comprising a plurality of first wires (211) arranged in a snake shape and a plurality of second wires (212) arranged in a snake shape, the plurality of first wires (211) extending along a first direction and being arranged at intervals in a second direction, the plurality of second wires (212) extending along a second direction and being arranged at intervals in a first direction, the first wires (211) and the second wires (212) being crossed and connected to enclose a plurality of array-distributed blank areas (213), the plurality of first wires (211) being intermittently formed with first connecting points (211a) and second connecting points (211b), the first connecting points (211a) and the second connecting points (211b) being connected areas (214), and the second wires (212) being continuous and uninterrupted; the intermittent end of each first wire (211) is bent in a direction away from the flexible stretchable substrate (1) to form a bending part (215), and then is bent in a direction parallel to the flexible stretchable substrate to form a supporting part (216); a plurality of components (3) corresponding to the connecting areas (214), the positive and negative poles of the components (3) corresponding to and connected with the supporting parts (216) of the first connecting points (211a) and the second connecting points (211b) respectively; and a packaging body (4) arranged on the flexible stretchable substrate (1), the wire unit (2) and the components (3) being covered in the packaging body (4), and the material of the packaging body (4) being a flexible stretchable material; and a woven fabric (5) fixed to the side of the flexible stretchable substrate (1) opposite to the wire unit (2), the woven fabric (5) corresponding to the bending parts (215) and the supporting parts (216) being hardened areas (51). The first wire (211) between every two adjacent second wires (212) is intermittently formed with a connecting area (214); and / or The component (3) is an LED chip; and / or The cross-sectional area of the first wire (211) and the second wire (212) gradually increases from the middle part to the two ends. The positive wire (22) and the negative wire (23) are arranged in a snake shape and extend along the first direction, the positive wire (22), the middle wire (21) and the negative wire (23) are arranged at intervals in the second direction in sequence, and the plurality of second wires (212) are alternately connected with the positive wire (22) and the negative wire (23). The cross-sectional area of the positive wire (22) and the negative wire (23) gradually increases from the middle part to the two ends.

2. The flexible stretchable circuit of claim 1, wherein, The wire unit (2) is arranged in an integral mode. The application further relates to a manufacturing method of the flexible stretchable substrate (1), the wire unit (2), the components (3) and the packaging body (4). ​ 3. The flexible stretchable circuit of claim 1, wherein, ​ 4. The flexible stretchable circuit of claim 3, wherein, ​ 5. The flexible stretchable circuit of any of claims 1 to 4, wherein, ​ 6. A method of making a flexible stretchable circuit, characterized by, ​ S1: prepare a wire unit (2), the wire unit (2) comprising a middle wire (21), a positive electrode wire (22) and a negative electrode wire (23) both connected with the middle wire (21), the middle wire (21) comprising a plurality of first wires (211) each arranged in a snake shape and a plurality of second wires (212) each arranged in a snake shape, the plurality of first wires (211) each extending along a first direction and being arranged at intervals in a second direction, the plurality of second wires (212) each extending along a second direction and being arranged at intervals in a first direction, the first wires (211) and the second wires (212) being crossed and connected to enclose a plurality of array-distributed blank areas (213), the plurality of first wires (211) being intermittently formed with a first connecting point (211a) and a second connecting point (211b), the first connecting point (211a) and the second connecting point (211b) being connected with a connecting area (214) therebetween, and the second wire (212) being continuous and uninterrupted; the intermittently formed end of each first wire (211) being bent in a direction away from the flexible stretchable substrate (1) to form a bending portion (215), and then being bent in a direction parallel to the flexible stretchable substrate to form a supporting portion (216); and, S2: provide a flexible stretchable substrate (1), adhere the wire unit (2) to the flexible stretchable substrate (1); mount each component (3) to each connecting area (214), and weld the positive and negative electrodes of the component (3) to the supporting portion (216) of the first connecting point (211a) and the supporting portion (216) of the second connecting point (211b) respectively and one by one; encapsulate the wire unit (2) and the component (3) with a flexible stretchable material to form an encapsulation (4) located on the flexible stretchable substrate (1) and covering the wire unit (2) and the component (3); and fix a woven fabric (5) to the side of the flexible stretchable substrate (1) opposite to the wire unit (2), the positions corresponding to the bending portion (215) and the supporting portion (216) of the woven fabric (5) being hardened areas (51).

7. The method of claim 6, wherein the flexible stretchable circuit is prepared by, In step S1, the step of preparing the wire unit (2) is: providing a conductive plate, cutting the conductive plate according to a preset pattern to form the wire unit (2).

8. The method of claim 7, wherein the flexible stretchable circuit is prepared by, In step S1, the conductive plate is cut so that the first connecting point (211a) and the second connecting point (211b) extend in opposite directions to form an extension piece (217), the extension piece (217) is bent in a direction away from the flexible stretchable substrate (1) to form a bending portion (215), and then is bent in a direction parallel to the flexible stretchable substrate to form a supporting portion (216); In step S2, after the wire unit (2) is adhered to the flexible stretchable substrate (1), the bending part (215) is encapsulated to form a first encapsulation layer (41) on the flexible stretchable substrate (1) to cover the bending part (215) and expose the supporting part (216); the component (3) is attached to the supporting part (216), and the component (3) and the supporting part (216) are welded; and the supporting part (216) and the component (3) are encapsulated to form a second encapsulation layer (42) on the first encapsulation layer (41).

9. The method of claim 7, wherein the flexible stretchable circuit is prepared by, In step S1, the conductive plate is cut to make the positive wire (22) and the negative wire (23) both in a snake shape and extend along the first direction, and the positive wire (22), the intermediate wire (21), and the negative wire (23) are sequentially and spaced apart in the second direction, and a plurality of the second wires (212) are alternately connected with the positive wire (22) and the negative wire (23).

10. An electronic device, comprising: A flexible stretchable circuit as claimed in any one of claims 1 to 5.

Images