Flexible and stretchable wiring structure and phototherapy skin patch

Abstract

The invention discloses a flexible and stretchable wiring structure, and relates to the technical field of flexible and stretchable electronics. The wiring structure comprises a stretchable base material and a conductive circuit formed on the stretchable base material, the conductive circuit comprises a wiring part, an interconnection part and an external connection part, the wiring part, the interconnection part and the external connection part are sequentially connected, the external connection part is used for being connected with other conductive structures, the wiring part and the interconnection part are of stretchable structures, and the external connection part is of a tensile structure; the length of the contact surface of the interconnection part and the external connection part is not less than 1 / 3 of the perimeter of the first external connection part, and at least one inflection point exists; and the wiring part comprises a single wiring structure formed by mutually connecting at least two single S conductive circuits laid in parallel. According to the embodiment of the invention, the wiring part of the single wiring structure in which multiple lines are interwoven and connected in parallel is designed, and the stretchable interconnection part is additionally arranged between the wiring part and the external connection part, so that the length of the contact surface between the stretchable interconnection part and the tensile external connection part is increased, and meanwhile, the contact surface is designed to have at least one inflection point; the anti-tensile open circuit risk of the whole wiring part, the interconnection part and the external connection part can be effectively improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of flexible stretchable electronics, and particularly relates to a flexible stretchable wiring structure and a phototherapy skin patch. BACKGROUND

[0002] The phototherapy skin patch refers to a product for skin care and beauty using light, and the market has developed phototherapy masks, phototherapy eye patches, and other phototherapy products for different parts.

[0003] In recent years, in order to meet the wearing experience of users, many manufacturers have launched their own flexible phototherapy products, most of which are based on PI film (polyimide) FPC flexible circuit board products to meet the flexible and foldable needs of users. In order to improve the skin-friendliness of the FPC flexible circuit board, TPU and similar materials with skin-friendliness are used for surface packaging of the FPC, further improving the wearing experience of users.

[0004] With the continuous development of technology and life, the simple flexible phototherapy skin patch is not enough to meet the increasing needs of users, and the product also needs to have certain stretchability to meet the needs of users for the appropriate stretchability of the product. However, the structure and performance of the flexible stretchable electronics on the market are not stable and reliable, and therefore the phototherapy product is difficult to be further optimized in this direction. SUMMARY

[0005] Therefore, an object of the present application is to provide a flexible stretchable wiring structure to solve the problem of poor structure and performance reliability of the flexible stretchable electronics in the prior art.

[0006] In some illustrative embodiments, the flexible stretchable wiring structure comprises: a stretchable substrate, a first conductive line formed on the stretchable substrate; the first conductive line comprises: a first wiring part, a first interconnection part, and a first external connection part for connecting other conductive structures, the first wiring part and the first external connection part are connected through the first interconnection part; the first wiring part and the first interconnection part are stretchable structures, and the first external connection part is a stretch-resistant structure; the length of the contact surface between the first interconnection part and the first external connection part is not less than 1 / 3 of the circumference of the first external connection part, and there is at least one inflection point between the contact surface of the first interconnection part and the first external connection part; the first wiring part comprises a single wiring structure formed by interconnecting at least two parallel laid single S conductive lines.

[0007] In some optional embodiments, the wiring structure further comprises: a hardening part for converting the first external connection part of the stretchable structure into the stretch-resistant structure.

[0008] In some alternative embodiments, the wiring structure further comprises: a second conductive circuit formed on the stretchable substrate, and located on the same side of the stretchable substrate as the first conductive circuit; the second conductive circuit comprises: a second trace portion, a second interconnection portion, and a second external connection portion for connecting other conductive structures, the second trace portion and the second external connection portion are connected through the second interconnection portion; the second interconnection portion is a stretchable structure, and the second external connection portion is a stretch-resistant structure; there is at least one inflection point on the contact surface between the second interconnection portion and the second external connection portion; the second trace portion comprises a single trace structure formed by interconnecting at least two parallel laid single S conductive circuits with each other; the first external connection portion of the first conductive circuit is opposite to the second external connection portion of the second conductive circuit; the hardening portion simultaneously converts the first external connection portion and the second external connection portion of the stretchable structure into the stretch-resistant structure.

[0009] In some alternative embodiments, the wiring structure further comprises: an electronic device, two different pins on the electronic device are connected to the first external connection portion and the second external connection portion, respectively; and the hardening portion is formed by a curing glue covering the electronic device, the first external connection portion, and the second external connection portion.

[0010] In some alternative embodiments, the first trace portion, the first interconnection portion, and the first external connection portion are elastic circuits formed by printing with low-temperature conductive paste, and the electrical elongation of the elastic circuits is not less than 50%.

[0011] In some alternative embodiments, the contact surface between the first interconnection portion and the first external connection portion is an arc structure, and the central angle of the arc structure is not less than 120°.

[0012] In some alternative embodiments, the line width of the first trace portion is smaller than the first interconnection portion; and / or, the length of the contact surface between the first interconnection portion and the first external connection portion is greater than the line width of the first trace portion.

[0013] In some alternative embodiments, the number of single S conductive circuits is 2n+1; n is a non-zero natural number.

[0014] In some alternative embodiments, the interconnection structure between the single S conductive circuits comprises at least one of the following structures: contact connection between adjacent single S conductive circuits, overlapping connection between adjacent single S conductive circuits, and staggered connection between adjacent single S conductive circuits.

[0015] Another object of the present application is to provide a phototherapy skin patch to solve the problems in the prior art.

[0016] In some illustrative embodiments, the phototherapy skin patch includes any of the flexible and stretchable wiring structures described above.

[0017] Compared with the existing technology, this application has the following advantages:

[0018] In the embodiment of the present invention, a routing portion of a single routing structure with multiple lines interwoven in parallel is designed, and an additional stretchable interconnection portion is added between the routing portion and the external connection portion. The length of the contact surface between the stretchable interconnection portion and the stretch-resistant external connection portion is increased, and at the same time, the contact surface is designed to have at least one inflection point, which can effectively improve the overall stretch-resistant circuit breaker risk of the routing portion, the interconnection portion and the external connection portion. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A schematic diagram of a stretchable wiring structure in the prior art is shown;

[0020] Figure 2 This is a structural example 1 of a flexible and stretchable wiring structure in an embodiment of the present invention;

[0021] Figure 3 This is a structural example 1 of the routing portion in an embodiment of the present invention;

[0022] Figure 4 This is a second structural example of the routing portion in an embodiment of the present invention;

[0023] Figure 5 This is a third structural example of the routing portion in an embodiment of the present invention;

[0024] Figure 6 This is a fourth structural example of the routing portion in an embodiment of the present invention;

[0025] Figure 7 This is a fifth structural example of the routing portion in an embodiment of the present invention;

[0026] Figure 8 This is a second structural example of a flexible and stretchable wiring structure in an embodiment of the present invention;

[0027] Figure 9 A schematic diagram of a prior art dispensing packaging structure is shown;

[0028] Figure 10 It is a cross-sectional view of a dispensing packaging structure in the prior art;

[0029] Figure 11 This is a structural example 3 of the flexible and stretchable wiring structure in an embodiment of the present invention;

[0030] Figure 12 This is a fourth structural example of a flexible and stretchable wiring structure in an embodiment of the present invention;

[0031] Figure 13 This is a structural example 5 of the flexible and stretchable wiring structure in the embodiment of the present invention;

[0032] Figure 14 This is structural example six of the flexible and stretchable wiring structure in an embodiment of the present invention. DETAILED DESCRIPTION

[0033] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0034] It should be noted that the various technical features in the embodiments of the present invention can be combined with each other without conflict.

[0035] like Figure 1 As shown, Figure 1 A schematic diagram of a stretchable routing structure in the prior art is shown, which is a single S-shaped conductive circuit 2 provided on a stretchable substrate 1. The single S-shaped conductive circuit is mostly a non-stretchable structure, such as an etched circuit formed by etching copper foil or a non-stretchable printed circuit formed by printing a conductive paste and curing it. The stretchable principle of the routing structure is mainly based on the stretchable properties of the stretchable substrate. During the stretching process, the substrate will be stretched and deformed at the stress point, and the single S-shaped conductive circuit at this point will only narrow and straighten because it does not have stretchable properties. However, if the stress point is on the single S-shaped conductive circuit, then this point of the single S-shaped conductive circuit is very likely to be broken, resulting in the failure of the entire routing circuit.

[0036] The embodiment of the present invention discloses a flexible and stretchable wiring structure, specifically, as Figure 2-8 As shown, Figure 2 This is a structural example 1 of a flexible and stretchable wiring structure in an embodiment of the present invention; Figure 3 This is a structural example 1 of the routing portion in an embodiment of the present invention; Figure 4 This is a second structural example of the routing portion in an embodiment of the present invention; Figure 5 This is a third structural example of the routing portion in an embodiment of the present invention; Figure 6 This is a fourth structural example of the routing portion in an embodiment of the present invention; Figure 7 This is a fifth structural example of the routing portion in an embodiment of the present invention; Figure 8This is a second structural example of a flexible and stretchable wiring structure in an embodiment of the present invention; the flexible and stretchable wiring structure includes: a stretchable substrate 10, and a routing portion formed on the stretchable substrate 10; wherein the routing portion is a stretchable structure, including: a single routing structure formed by interconnecting at least two single S conductive lines a laid in parallel.

[0037] The "single trace structure" in the embodiments of the present invention specifically refers to a conductive structure that serves as a conductive line or realizes the function of a conductive line, and has only two line ends, which are usually used to connect the positive electrode and the negative electrode respectively. Furthermore, for example, two LEDs (Light-Emitting Diodes) are connected through the single trace structure in the embodiments of the present invention, wherein the two ends of the single trace structure are respectively connected to a pin of each of the two LEDs, and the end of each corresponding single S conductive line at the end of the single trace structure is used to connect to this pin. The LED can also be replaced with other conductive lines, conductive structures, etc., as well as other electronic components such as chips, resistors, inductors, capacitors, etc.

[0038] Those skilled in the art should note that the above embodiments are mainly aimed at improving and optimizing the circuit itself. The embodiments of the present invention do not strictly limit the end of each corresponding single S conductive circuit at the end of a single wiring structure to be connected to the target pin (or target electron). In theory, as long as the end of one of the single S conductive circuits is connected to the target pin, the conduction between the two can be satisfied.

[0039] In the embodiment of the present invention, the routing portion is a single stretchable routing structure formed by interconnecting at least two single S conductive lines laid in parallel. Compared with the traditional single S routing structure, the single routing structure of the present application is composed of multiple lines interwoven in parallel. Therefore, when a local line is over-stretched and causes a circuit break, the other lines in the parallel structure can still ensure that the routing portion as a whole maintains its conductive performance, effectively reducing the risk of the routing portion breaking due to stretching.

[0040] The single S-shaped conductive lines in the embodiments of the present invention refer to regularly arranged meandering structures. The single S-shaped conductive lines are not limited to arc structures. In addition to arc structures, they may also adopt sharp-angled meandering structures, right-angled meandering structures, obtuse-angled meandering structures, or combinations of any two of the aforementioned meandering structures.

[0041] Preferably, the single S conductive circuit in the embodiment of the present invention is an arc structure, thereby reducing the length of the "straight line" segment in the single S conductive circuit, thereby reducing the risk of excessive stretching and breaking at a specific point (straight line segment) in a specific stretching direction (extension direction of the straight line segment).

[0042] In some embodiments, the interconnection structure between the single S conductive lines in the embodiments of the present invention includes at least one of the following structures: contact connection between adjacent single S conductive lines, overlapping connection between adjacent single S conductive lines, and staggered connection between adjacent single S conductive lines.

[0043] Among them, contact connection between adjacent single-S conductive circuits refers to rigid contact between adjacent single-S conductive circuits, and the line width of the connection point is twice the line width of the single-S conductive circuit; overlapping connection between adjacent single-S conductive circuits refers to partial overlap of the contact points between adjacent single-S conductive circuits, but the overlapping range does not exceed the single line width of the single-S conductive circuit, and the line width of the connection point is between the single line width of the single-S conductive circuit and twice the line width; staggered connection between adjacent single-S conductive circuits refers to the staggered connection between adjacent single-S conductive circuits into their respective graphic areas.

[0044] For example, Figure 5-7 As shown, a single S conductive circuit with a chord curve (i.e., arc structure) is used as an example. Figure 5 As shown, the contact connection between adjacent single S conductive lines includes: the points of the crests and troughs between the adjacent single S conductive lines just touch but do not overlap; Figure 6 As shown, the overlapping connection between adjacent single S conductive lines includes: the points of the crests and troughs between the adjacent single S conductive lines are in contact and overlapped, and the overlapping range does not exceed the single line width of the single S conductive line; Figure 7 As shown, the staggered connection between adjacent single S conductive lines includes: the crests and troughs between the adjacent single S conductive lines are staggered with each other, and an additional connection point is generated, and the two connection points are located on both sides of the crest and trough.

[0045] The number of single S conductive lines laid in parallel in the embodiment of the present invention can be 2, 3, 4, 5, ..., 10, ... and so on. Those skilled in the art can make a choice based on the actual laying range, conductivity and other conditions and requirements. This application does not impose a specific upper limit on the number of single S conductive lines.

[0046] Preferably, the number of single-S conductive lines in the embodiments of the present invention is 2n+1, where n is a non-zero natural number, such as 3, 5, 7, 9, 11, and so on. A wiring section composed of 2n+1 single-S conductive lines laid in parallel can form a regularly arranged equivalent pattern along the overall wiring extension direction, and even form a nearly equivalent conductive structure at any point along the wiring extension direction, thereby improving resistance consistency during stretching.

[0047] In some embodiments, at least two parallel single-S conductive traces are located in the same plane, and the single trace structure is a planar structure. Compared to a heterogeneous structure (multi-planar structure), a planar single trace structure has a relatively simple structure and molding process, making it easier to implement. In other embodiments, the single trace structure in the embodiments of the present invention can also be formed on a heterogeneous structure, still achieving the same technical effect.

[0048] The single S conductive circuit in the embodiment of the present invention can be formed by a conductive paste printing process, or by chemical etching, laser etching, or other processes. The printing process is not limited to direct writing, inkjet printing, screen printing, transfer printing, lithography, gravure printing, or other patterning processes. Alternatively, the circuit pattern can be formed by coating or other processes, followed by a subtractive process to form the circuit pattern.

[0049] Preferably, at least a portion of the single-S conductive lines in the embodiments of the present invention are formed from a conductive paste. The conductive paste can be a low-temperature conductive paste with a resin as the binder phase, or a high-temperature conductive paste with a glass frit as the binder phase. For example, the low-temperature conductive paste used in the embodiments of the present invention offers advantages over high-temperature conductive pastes in terms of simpler processing, lower curing temperature, and a wider range of substrate options.

[0050] The low-temperature conductive paste in the embodiment of the present invention mainly includes resin and conductive filler; wherein the conductive filler is not limited to one or more of gold, silver, copper, iron, nickel, zinc, aluminum, palladium, conductive carbon black, and graphene.

[0051] The low-temperature conductive paste in the embodiment of the present invention may further include a corresponding solvent before curing to form a printable paste. In addition, the low-temperature conductive paste in the embodiment of the present invention may further include a corresponding functional additive to enhance the corresponding properties of the paste.

[0052] Furthermore, in the embodiment of the present invention, at least part of the single S conductive circuits are elastic circuits, and the power-off elongation of the elastic circuits is not less than 50%.

[0053] The elastic circuit in the embodiment of the present invention can be formed by an elastic conductive paste (also known as a stretchable conductive paste) through a printing process. The elastic conductive paste in the embodiment of the present invention is a low-temperature conductive paste with a resin as a binder phase, mainly including: conductive filler, resin and solvent. The resin system contains an elastic resin component, which gives it elastic and stretchable properties. After the elastic conductive paste is printed, formed and cured, the main structure of the elastic conductive printed circuit formed is conductive particles and a resin film that binds the conductive particles.

[0054] The elastic resin contained in the resin system in the embodiment of the present invention is not limited to one or more of silicone resin, TPU resin, SEBS resin, and SIS resin.

[0055] Those skilled in the art should note that although the elastic conductive paste referred to in this application is a low-temperature conductive paste, it is different from traditional ordinary low-temperature conductive pastes. Although after curing and molding, it also has the main structure of conductive particles and a resin film that binds the conductive particles, its resin system contains almost no elastic properties, or the elastic properties are relatively low, resulting in the entire structure after curing being brittle. Under repeated bending, the problem of circuit breakage and peeling is more likely to occur.

[0056] Since the elastic properties of the elastic conductive paste depend on its overall material system, such as the specific composition, component ratio, preparation process, etc., and the material system is too complex, the present invention does not limit the elastic conductive paste, and further specifically limits the elastic conductive printed circuit; specifically, the elastic conductive printed circuit in the embodiment of the present invention is a conductive printed circuit formed by a low-temperature conductive paste and having an off-state elongation of not less than 50%. If the off-state elongation is less than 50%, the problem of poor tensile conductive effect is likely to occur.

[0057] The power-off elongation in the embodiments of the present invention refers to the maximum degree of stretching of an elastic conductor (such as the elastic circuit in this application) while maintaining its conductive properties (circuit conduction). The power-off elongation of the elastic circuit in the embodiments of the present invention is measured using an elastic conductive printed circuit with a width of 5000 μm and a thickness of 10 μm. Therefore, when measuring the power-off elongation of an elastic conductive printed circuit, those skilled in the art should require that the cross-sectional area (perpendicular to the stretching direction) of the elastic circuit be no less than 5×10 4 μm 2 .

[0058] For example, an elastic circuit with a length of 10 cm, a width of 5000 μm, and a thickness of 10 μm is stretched to 15 cm along its length, and the stretching degree reaches 50%. At this time, the elastic circuit still maintains its conductive properties, that is, the power-off elongation of the elastic circuit reaches at least 50%.

[0059] In the embodiments of the present invention, an elastic circuit formed from an elastic conductive paste is used as a single S conductive circuit. This allows the single S conductive circuit itself (in a straight structure) to have a certain degree of stretchability. Therefore, it can be more firmly attached to the stretchable substrate during stretching than a conductive circuit with a rigid structure. This reduces the risk of the single S conductive circuit collapsing or peeling during stretching, further improving its reliability.

[0060] Furthermore, the tensile modulus of the single-S conductive traces in this embodiment of the present invention is greater than that of the stretchable substrate. Under the same external force, the flexible stretchable wiring structure in this embodiment experiences less tensile deformation at the locations on the stretchable substrate where the single-S conductive traces are located compared to locations where non-single-S conductive traces are located, thereby further improving product reliability.

[0061] like Figure 8 As shown, in some embodiments, the flexible and stretchable wiring structure may further include: an external connection portion 20 connected to at least one end of a single routing structure for connecting to other conductive structures (non-routing portions); wherein the external connection portion 20 is directly connected to the end of each single S conductive line. The external connection portion includes, but is not limited to, electrodes or pads for connecting to other conductive structures. Other conductive structures include, but are not limited to, circuit boards, electronic devices, conductive bridge structures, and other conductive lines. Electronic devices include, but are not limited to, LEDs (including MiniLEDs, OLEDs, microLEDs, etc.), chips (also known as integrated circuits), resistors, inductors, capacitors, and other electronic components. The external connection portion in this embodiment may be a solid, monolithic pattern to facilitate connection to other conductive structures.

[0062] The stretchable substrate in the embodiment of the present invention includes but is not limited to stretchable materials such as TPU, TPE, PDMS, silicone, and fabric.

[0063] Another object of the present invention is to provide a phototherapy skin patch based on the aforementioned flexible and stretchable wiring structure; the phototherapy skin patch includes any of the aforementioned flexible and stretchable wiring structures. The phototherapy skin patch can be applied to areas other than the face, eyes, chin, torso, hands, and legs, and can be tailored to the specific area of ​​interest. Specifically, the phototherapy skin patch may include a phototherapy facial mask or a phototherapy eye patch.

[0064] like Figure 9-10 As shown, Figure 9 A schematic diagram of a prior art dispensing packaging structure is shown. Figure 10This is a cross-sectional view of a glue-dot packaging structure in the prior art. This glue-dot packaging structure is mainly used for packaging and curing at the connection between conductive circuits and electronic devices on flexible non-stretchable (i.e. FPC) electronics to improve the reliability of the connection between the two. The conductive circuit in this structure mainly includes a substrate 3, and traces 4 and pads 5 formed on the substrate 3. Usually, in order to miniaturize the circuit board, the pads 5 will be made to conform to the electrode pins of the electronic device 6, and the sizes of the two are almost the same, so the size of the pads is actually very small, and the line width of the traces 4 connected to the pads 5 is at most the same width as the pads 5, or even smaller than the pads 5; and in order to ensure the stability of the connection structure between the pads 5 and the electronic device 6 in current technology, the encapsulation glue 7 will completely cover the pads 5, the electronic device 6, and part of the traces 4, so the edge of the encapsulation glue 7 actually falls on the traces 4, and if the above-mentioned FPC packaging structure is applied to flexible and stretchable electronics, it is easy to cause defects. This is mainly because the tensile modulus of the encapsulation glue 7 is extremely large and extremely difficult to stretch, and can even be considered unstretchable. At the same time, since the line width of the traces 4 is very small, this easily leads to the risk of the traces at the edge of the encapsulation glue 7 being stretched and broken during the stretching process.

[0065] To this end, an embodiment of the present invention discloses a flexible and stretchable wiring structure, specifically, as Figure 11-13 As shown, Figure 11 This is a structural example 3 of the flexible and stretchable wiring structure in an embodiment of the present invention; Figure 12 This is a fourth structural example of a flexible and stretchable wiring structure in an embodiment of the present invention; Figure 13 This is a structural example five of a flexible and stretchable wiring structure in an embodiment of the present invention; the wiring structure includes: a stretchable substrate 10, a first conductive circuit 30 formed on the stretchable substrate 10; the first conductive circuit 30 includes: a first routing portion 31, a first interconnection portion 32, and a first external connection portion 33 for connecting other conductive structures, and the first routing portion 31 and the first external connection portion 33 are connected through the first interconnection portion 32; the first interconnection portion 32 is a stretchable structure, and the first external connection portion 33 is an anti-stretching structure; the length of the contact surface between the first interconnection portion 32 and the first external connection portion 33 is not less than 1 / 3 of the circumference of the first external connection portion 32, and there is at least one inflection point on the contact surface between the first interconnection portion 32 and the first external connection portion 33.

[0066] In the embodiment of the present invention, an additional stretchable interconnection portion is added between the routing portion and the external connection portion, and the length of the contact surface between the stretchable interconnection portion and the stretch-resistant external connection portion is designed to be no less than 1 / 3 of the circumference of the external connection portion, thereby effectively increasing the size of the contact surface between the stretchable conductive structure and the stretch-resistant conductive structure. At the same time, the contact surface is designed to have at least one inflection point, that is, the contact surface between the interconnection portion and the external connection portion includes at least two contact surfaces in different directions, which can reduce the risk of circuit breakage when stretched in a single direction.

[0067] Among them, the longer the length of the contact surface between the stretchable interconnection part and the anti-stretch external connection part, the better the anti-stretch circuit breaking performance. Technical personnel in this field can choose between 1 / 3 of the circumference of the external connection part and the entire circumference of the external connection part according to actual needs, including but not limited to not less than 1 / 2 of the circumference, 2 / 3 of the circumference, an entire circumference, etc.

[0068] In the embodiments of the present invention, a stretch-resistant structure refers to a structure that has lower stretchability than a stretchable structure. Specifically, the tensile modulus of the outer connecting portion of the stretch-resistant structure should be greater than the tensile modulus of the interconnecting portion of the stretchable structure, and the tensile modulus of the outer connecting portion of the stretch-resistant structure should be greater than the tensile modulus of the stretchable substrate. Furthermore, the tensile modulus of the outer connecting portion of the stretch-resistant structure is at least 10 times the tensile modulus of the interconnecting portion of the stretchable structure / the stretchable substrate. Furthermore, the first outer connecting portion may be a non-stretchable structure.

[0069] In the embodiment of the present invention, the existence of at least one inflection point on the contact surface between the first interconnecting portion 32 and the first external connecting portion 33 means that there is at least one inflection point on the line segment of the contact surface in the horizontal direction of the stretchable substrate, that is, the line is a bending structure including at least one inflection point.

[0070] Preferably, in the embodiment of the present invention, the contact surface between the first interconnecting portion 32 and the first external connecting portion 33 is an arc structure, with a central angle of no less than 120°. An arc structure can be considered to have several inflection points. Therefore, compared to other structures, the contact surface of an arc structure allows the first interconnecting portion 32 and the first external connecting portion to form a connection in more directions, further improving the tensile fracture resistance between the two.

[0071] Specifically, the central angle of the arc structure can be selected between 120° and 360°; further, the central angle of the arc structure can be 130°, 150°, 180°, 240°, 360°, etc.

[0072] In some embodiments, the line width of the first routing portion 31 is smaller than that of the first interconnection portion 32. Specifically, the smaller line width of the first routing portion 31 than that of the first interconnection portion 32 can be considered to indicate the presence of a diameter-varying structure at the connection along the direction of extension between the two. In other embodiments, the line width of the first routing portion 31 can be equal to or greater than that of the first interconnection portion 32. If the line widths of the first routing portion 31 and the first interconnection portion 32 are equal, it is equivalent to the absence of a diameter-varying structure.

[0073] In some embodiments, the length of the contact surface between the first interconnection portion 32 and the first external connection portion 33 may be greater than the line width of the first routing portion 31. In other embodiments, the length of the contact surface between the first interconnection portion 32 and the first external connection portion 33 may also be less than or equal to the line width of the first routing portion 31.

[0074] In some embodiments, the flexible and stretchable wiring structure of the present invention may further include a hardening portion 40 for converting the first external connection portion 33, which is a stretchable structure, into a stretch-resistant structure. The hardening portion 40 acts on the first external connection portion 33. Therefore, if the hardening portion 40 is a stretch-resistant structure (or a non-stretchable structure), the first external connection portion 33 can be converted into a corresponding stretch-resistant structure (or non-stretchable structure). In other embodiments, the first external connection portion 33 may also directly adopt a stretch-resistant conductive structure or a non-stretchable conductive structure.

[0075] The hardened portion 40 in the embodiments of the present invention may be formed by, but is not limited to, applying a curing adhesive or converting the stretchability of the corresponding region of the stretchable substrate into a stretch-resistant or non-stretchable state. The method for converting the properties is not limited to illumination, heating, etc. In other embodiments, the hardened portion 40 may also be made of other stretch-resistant or non-stretchable materials.

[0076] In some embodiments, the first interconnect 32 of the present invention may be an elastic circuit (i.e., a stretchable structure) formed by printing a low-temperature conductive paste, with the elastic circuit exhibiting a power-off elongation of no less than 50%. The relevant components and properties of the elastic circuit formed by printing a low-temperature conductive paste, as well as the definition and determination of power-off elongation, can be found in the aforementioned embodiments and will not be further elaborated here.

[0077] Preferably, the first wiring portion 31, first interconnect portion 32, and first external connection portion 33 in the embodiment of the present invention are elastic circuits formed by printing a low-temperature conductive paste, and the elastic circuit has a power-off elongation of no less than 50%. In other embodiments, the first wiring portion 31 and first external connection portion 33 may also be non-stretchable circuits formed by printing a low-temperature conductive paste.

[0078] In some embodiments, at least a portion of the first external connection portion 33 in the embodiment of the present invention can be used as a pad to connect to other conductive structures such as electronic devices.

[0079] The flexible stretchable wiring structure in the embodiment of the present invention can be applied to stretchable conductive structures that are locally resistant to stretching (or non-stretching), including: stretchable conductive structures involved in the packaging and fixation of electronic devices, and other stretchable circuit boards that are locally resistant to stretching.

[0080] In some embodiments, the flexible and stretchable wiring structure in the embodiments of the present invention may further include: a second conductive circuit 50 formed on the stretchable substrate 10, located on the same side of the stretchable substrate 10 as the first conductive circuit 30; the second conductive circuit 50 includes: a second routing portion 51, a second interconnection portion 52, and a second external connection portion 53 for connecting to other conductive structures, the second routing portion 51 and the second external connection portion 53 being connected via the second interconnection portion 52; the second interconnection portion 52 is a stretchable structure, and the second external connection portion 53 is an anti-stretching structure; the length of the contact surface between the second interconnection portion 52 and the second external connection portion 53 is not less than 1 / 3 of the circumference of the second external connection portion 53, and the contact surface between the second interconnection portion 52 and the second external connection portion 53 has at least one inflection point;

[0081] The first external connection portion 33 of the first conductive circuit 30 is opposite to the second external connection portion 53 of the second conductive circuit 50 ; the hardening portion 40 simultaneously converts the first external connection portion 33 and the second external connection portion 53 of the stretchable structure into an anti-stretching structure (or a non-stretching structure).

[0082] The second conductive circuit 50 in this embodiment can be the same as the first conductive circuit 30 . The second routing portion 51 can refer to the first routing portion 31 , the second interconnecting portion 52 can refer to the first interconnecting portion 32 , and the second external connecting portion 53 can refer to the first external connecting portion 33 .

[0083] Furthermore, the flexible and stretchable wiring structure in the embodiment of the present invention may also include: an electronic device 60, two different pins on the electronic device 60 are respectively connected to the first external connection part 33 and the second external connection part 53; the hardened part 40 is formed by the curing glue covering the electronic device 60, the first external connection part 33 and the second external connection part 53.

[0084] The electronic device 60 includes but is not limited to LEDs (including MiniLED, OLED, microLED, etc.), chips (also called integrated circuits), resistors, inductors, capacitors and other electronic components.

[0085] The embodiment of the present invention does not limit the interconnection method between the external connection part and the electronic device, and conductive interconnection can be achieved through welding, conductive adhesive, etc.

[0086] Those skilled in the art will appreciate that embodiments of the present invention may further include third and fourth conductive traces to accommodate more connections, such as for multi-pin chips. Furthermore, for multi-pin chips with similar connection requirements, only two different pins may be connected using the first and second conductive traces of the embodiments of the present invention.

[0087] The stretchable substrate in the embodiment of the present invention includes but is not limited to stretchable materials such as TPU, TPE, PDMS, silicone, and fabric.

[0088] Another object of the present invention is to provide a phototherapy skin patch based on the aforementioned flexible and stretchable wiring structure; the phototherapy skin patch includes any of the aforementioned flexible and stretchable wiring structures. The phototherapy skin patch can be applied to areas other than the face, eyes, chin, torso, hands, and legs, and can be tailored to the specific area of ​​interest. Specifically, the phototherapy skin patch may include a phototherapy facial mask or a phototherapy eye patch.

[0089] The embodiment of the present invention further discloses a flexible and stretchable wiring structure, specifically, Figure 14 As shown, Figure 14 This is a structural example six of a flexible and stretchable wiring structure in an embodiment of the present invention; the wiring structure comprises: a stretchable substrate 10, a first conductive circuit 30 formed on the stretchable substrate 10; the first conductive circuit 30 comprises: a first routing portion 31, a first interconnection portion 32, and a first external connection portion 33 for connecting other conductive structures, the first routing portion 31 and the first external connection portion 33 are connected via the first interconnection portion 32; the first routing portion 31 and the first interconnection portion 32 are stretchable structures, and the first external connection portion 33 is an anti-stretching structure; the length of the contact surface between the first interconnection portion 32 and the first external connection portion 33 is not less than 1 / 3 of the circumference of the first external connection portion 33, and there is at least one inflection point on the contact surface between the first interconnection portion 32 and the first external connection portion 33; the first routing portion 31 comprises: a single routing structure formed by interconnecting at least two single S conductive circuits a laid in parallel.

[0090] In the embodiment of the present invention, a routing portion of a single routing structure with multiple lines interwoven in parallel is designed, and an additional stretchable interconnection portion is added between the routing portion and the external connection portion. The length of the contact surface between the stretchable interconnection portion and the stretch-resistant external connection portion is increased, and at the same time, the contact surface is designed to have at least one inflection point, which can effectively improve the overall stretch-resistant circuit breaker risk of the routing portion, the interconnection portion and the external connection portion.

[0091] This embodiment combines the two aforementioned flexible and stretchable wiring structures. Therefore, the flexible and stretchable wiring structure in this embodiment has the technical effects of the two aforementioned flexible and stretchable wiring structures. At the same time, the wiring structure can constitute a complete stretchable conductive circuit.

[0092] In addition, this combination scheme can arbitrarily combine the above two flexible and stretchable wiring structure embodiments without conflict, including but not limited to the following combined embodiments.

[0093] In some embodiments, the flexible and stretchable wiring structure in the embodiments of the present invention may further include: a hardening portion 40 for converting the first external connection portion 31 of the stretchable structure into an anti-stretching structure.

[0094] In some embodiments, the flexible and stretchable wiring structure in the embodiments of the present invention may further include: a second conductive circuit 50 formed on the stretchable substrate 10, which is located on the same side of the stretchable substrate 10 as the first conductive circuit 30; the second conductive circuit 50 includes: a second routing portion 51, a second interconnecting portion 52, and a second external connecting portion 53 for connecting other conductive structures, and the second routing portion 51 and the second external connecting portion 53 are connected through the second interconnecting portion 52; the second interconnecting portion 52 is a stretchable structure, and the second external connecting portion 53 is an anti-stretching structure; there is at least one inflection point on the contact surface between the second interconnecting portion 52 and the second external connecting portion 53; the second routing portion 51 includes: a single routing structure formed by interconnecting at least two single S conductive circuits a laid in parallel.

[0095] In some embodiments, the first outer connecting portion 33 of the first conductive circuit 30 is opposite to the second outer connecting portion 53 of the second conductive circuit 50 ; the hardening portion 40 simultaneously converts the first outer connecting portion 33 and the second outer connecting portion 53 of the stretchable structure into a stretch-resistant structure.

[0096] In some embodiments, the flexible and stretchable wiring structure in the embodiments of the present invention may further include: an electronic device 60, two different pins on the electronic device 60 are respectively connected to the first external connection part 33 and the second external connection part 53; the hardened part 40 is formed by the curing glue covering the electronic device 60, the first external connection part 33 and the second external connection part 53.

[0097] In some embodiments, the first routing portion 31 (and the second routing portion 53), the first interconnection portion 32 (and the second interconnection portion 52), and the first external connection portion 33 (and the second external connection portion 53) in the embodiments of the present invention are elastic circuits formed by integrated printing of low-temperature conductive paste, and the power-off elongation of the elastic circuit is not less than 50%.

[0098] In some embodiments, the contact surface between the first interconnecting portion 32 and the first external connecting portion 33 is an arc structure, and the central angle of the arc structure is not less than 120°. The same applies to the second interconnecting portion 52 and the second external connecting portion 53.

[0099] In some embodiments, the line width of the first routing portion 31 in the embodiment of the present invention is smaller than that of the first interconnection portion 32 .

[0100] In some embodiments, the length of the contact surface between the first interconnection portion 32 and the first external connection portion 33 in the embodiment of the present invention is greater than the line width of the first routing portion 31 .

[0101] In some embodiments, the number of single S conductive circuits in the embodiments of the present invention is 2n+1, where n is a non-zero natural number.

[0102] In some embodiments, the interconnection structure between the single-S conductive lines in the embodiments of the present application comprises at least one of the following structures: contact connection between adjacent single-S conductive lines, overlapping connection between adjacent single-S conductive lines, and staggered connection between adjacent single-S conductive lines.

[0103] Another object of the present application is to provide a phototherapy skin patch based on the flexible stretchable wiring structure described above; the phototherapy skin patch comprises any of the flexible stretchable wiring structures described above. Wherein the phototherapy skin patch can be applied to parts such as face, eye, chin, torso, hand, leg, etc., and can be designed according to different parts. Specifically, the phototherapy skin patch can include: phototherapy mask, phototherapy eye patch, etc.

[0104] The "first" and "second" in the embodiments of the present application are only used to distinguish the same-named components, and do not specifically limit the number of components.

[0105] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A flexible and stretchable wiring structure, characterized in that: include: A stretchable substrate, a first conductive circuit formed on the stretchable substrate; The first conductive circuit includes: a first routing portion, a first interconnection portion, and a first external connection portion for connecting to other conductive structures, and the first routing portion and the first external connection portion are connected via the first interconnection portion; The first routing portion and the first interconnection portion are stretchable structures, and the first external connection portion is an anti-stretching structure; The length of the contact surface between the first interconnecting portion and the first external connecting portion is not less than 1 / 3 of the circumference of the first external connecting portion, and there is at least one inflection point on the contact surface between the first interconnecting portion and the first external connecting portion; The first routing portion includes: a single routing structure formed by interconnecting at least two single S conductive lines laid in parallel.

2. The flexible and stretchable wiring structure according to claim 1, characterized in that: Also includes: The hardening portion is used to convert the first outer connecting portion of the stretchable structure into the stretch-resistant structure.

3. The flexible and stretchable wiring structure according to claim 2, wherein: Also includes: a second conductive trace formed on the stretchable substrate, the second conductive trace being located on the same side of the stretchable substrate as the first conductive trace; The second conductive circuit includes: a second routing portion, a second interconnecting portion, and a second external connecting portion for connecting to other conductive structures, wherein the second routing portion and the second external connecting portion are connected via the second interconnecting portion; the second interconnecting portion is a stretchable structure, and the second external connecting portion is an anti-stretching structure; There is at least one inflection point on the contact surface between the second interconnecting portion and the second external connecting portion; The second routing portion comprises: a single routing structure formed by interconnecting at least two parallel laid single S conductive lines; The first external connection portion of the first conductive circuit is opposite to the second external connection portion of the second conductive circuit; The stiffening portion simultaneously converts the first outer connecting portion and the second outer connecting portion of the stretchable structure into the stretch-resistant structure.

4. The flexible and stretchable wiring structure according to claim 3, characterized in that: Also includes: an electronic device, wherein two different pins on the electronic device are respectively connected to the first external connection portion and the second external connection portion; The hardened portion is formed by curing glue covering the electronic device, the first external connection portion, and the second external connection portion.

5. The flexible and stretchable wiring structure according to claim 1, wherein: The first routing portion, the first interconnection portion, and the first external connection portion are elastic circuits formed by printing a low-temperature conductive paste, and the power-off elongation of the elastic circuit is not less than 50%.

6. The flexible and stretchable wiring structure according to claim 1, wherein: The contact surface between the first interconnecting portion and the first external connecting portion is an arc structure, and the central angle of the arc structure is not less than 120°.

7. The flexible and stretchable wiring structure according to claim 1, wherein: The line width of the first routing portion is smaller than that of the first interconnection portion; and / or, The length of the contact surface between the first interconnection portion and the first external connection portion is greater than the line width of the first routing portion.

8. The flexible and stretchable wiring structure according to claim 1, wherein: The number of the single S conductive circuits is 2n+1, where n is a non-zero natural number.

9. The flexible and stretchable wiring structure according to claim 1, wherein: The interconnection structure between the single S conductive lines includes at least one of the following structures: Adjacent single S conductive lines are contact-connected, adjacent single S conductive lines are overlap-connected, and adjacent single S conductive lines are staggered-connected.

10. A phototherapy skin patch, characterized in that: The invention comprises a flexible and stretchable wiring structure according to any one of claims 1 to 9.

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