Methods for fabricating conductive structures, display panels, flexible circuit boards, and conductive structures

Abstract

This disclosure provides a conductive structure, a display panel, a flexible circuit board, and a method for fabricating the conductive structure. The conductive structure includes a flexible insulating layer, conductive units, and a bonding layer. The flexible insulating layer includes a receiving cavity. The conductive units comprise a liquid conductive material and are filled within the receiving cavity. The bonding layer is located on the side of the flexible insulating layer facing the conductive units. The conductive structure of this disclosure uses a liquid conductive material as the conductive unit, which improves the flexibility of the conductive structure. The bonding layer is formed between the conductive units and the flexible insulating layer, ensuring good adhesion between them and preventing easy peeling, thus improving the reliability of the conductive structure.

Description

Technical Field

[0001] This disclosure relates to the field of display technology, specifically to a conductive structure, a display panel, a flexible circuit board, and a method for fabricating the conductive structure. Background Technology

[0002] Compared to traditional displays, flexible screens are not only thinner and lighter in size, but also consume less power than existing devices, which helps improve the battery life of devices. At the same time, due to their bendable and flexible characteristics, their durability is also much higher than that of traditional displays.

[0003] However, the flexibility of flexible screens still needs improvement. Therefore, how to improve the flexibility of flexible screens has become an urgent problem to be solved. Summary of the Invention

[0004] This disclosure provides a conductive structure, a display panel, a flexible circuit board, and a method for fabricating the conductive structure. The conductive structure uses a liquid conductive material as the conductive unit, which improves the flexibility of the conductive structure. Furthermore, a bonding layer is provided between the conductive unit and the flexible insulating layer encapsulating the conductive unit, ensuring good bonding between the conductive unit and the flexible insulating layer and preventing mechanical breakage of the conductive unit, thus improving the reliability of the conductive structure.

[0005] A first aspect of this disclosure provides a conductive structure comprising a flexible insulating layer, conductive units, and a bonding layer. The flexible insulating layer includes a receiving cavity. The conductive units are made of a liquid conductive material and fill the receiving cavity. The bonding layer is located on the side of the flexible insulating layer facing the conductive units and covers the conductive units.

[0006] The conductive unit is made of liquid conductive material. Since both the liquid conductive material and the flexible insulating layer possess excellent flexibility, incorporating the liquid conductive material within the flexible insulating layer enhances the flexibility of the conductive structure. The conductive unit is connected to the flexible insulating layer near its location via a bonding layer. This method prevents the conductive unit from peeling off from the flexible insulating layer, thus improving the reliability of the conductive structure.

[0007] In one specific embodiment of the first aspect of this disclosure, the flexible insulating layer is made of hydroxyl groups, the bonding layer is made of hydroxyl groups and metal oxides, and the liquid conductive material has the same metal ions as the metal oxides.

[0008] In one specific embodiment of the first aspect of this disclosure, the liquid conductive material is a liquid metal. This provides excellent bending resistance.

[0009] In one specific embodiment of the first aspect of this disclosure, the flexible insulating layer is a hydrophilic adhesive containing hydroxyl groups, the thickness of the flexible insulating layer is 2 micrometers to 10 micrometers, and the thickness of the conductive unit is 1 micrometer to 5 micrometers. By setting appropriate thickness ranges for the flexible insulating layer and the conductive unit, the excellent performance of the conductive structure can be effectively guaranteed.

[0010] In one specific embodiment of the first aspect of this disclosure, the conductive unit includes a wire. Specific implementations of the conductive unit are provided.

[0011] A second aspect of this disclosure provides a display panel including a display area, a bending area, and a bonding area, wherein the bending area is located between the display area and the bonding area. The display panel also includes a signal line extending from the display area to the bonding area. The portion of the display panel located in the bending area includes a conductive structure as described in the first aspect, and the portion of the signal line located in the bending area is a conductive unit within the conductive structure.

[0012] Applying conductive units, which use liquid conductive materials as conductive structures, to the bending area of ​​the display panel can improve the flexibility of the bending area, giving the display panel better bending performance.

[0013] A third aspect of this disclosure provides a flexible circuit board including a component area, a bending area, and a bonding area, wherein the bending area is located between the component area and the bonding area. The flexible circuit board also includes a signal line extending from the component area to the bonding area. The portion of the flexible circuit board located in the bending area includes a conductive structure as described in the first aspect, and the portion of the signal line located in the bending area is a conductive unit within the conductive structure.

[0014] Applying conductive units, which use liquid conductive materials as conductive structures, to the bending area of ​​flexible circuit boards can improve the flexibility of the bending area, thus giving the flexible circuit boards better bending performance.

[0015] The fourth aspect of this disclosure provides a method for preparing a conductive structure, the method comprising: providing a carrier plate and forming a flexible insulating layer on the carrier plate, wherein a cavity is formed in the flexible insulating layer; filling the cavity with a liquid conductive material; oxidizing the surface of the liquid conductive material, wherein a surface portion of the liquid conductive material is bonded to a surface portion of the flexible insulating layer facing the liquid conductive material to form a bonding layer, and the remaining portion of the liquid conductive material forms a conductive unit.

[0016] In one specific embodiment of the fourth aspect of this disclosure, forming a flexible insulating layer on a carrier substrate includes: forming a first adhesive layer on the carrier substrate; forming a second adhesive layer on the side of the first adhesive layer opposite to the carrier substrate; filling a cavity with a liquid conductive material includes: before forming the second adhesive layer, forming a patterned photoresist layer on the side of the first adhesive layer opposite to the carrier substrate, the photoresist layer including a through-groove, the bottom of the through-groove exposing the first adhesive layer; filling and solidifying the through-groove with a liquid conductive material; and removing the photoresist layer.

[0017] In one specific embodiment of the fourth aspect of this disclosure, forming a flexible insulating layer on a carrier plate includes: forming a first adhesive layer on the carrier plate, the first adhesive layer including a groove; and forming a second adhesive layer on the side of the first adhesive layer opposite to the carrier plate; filling a receiving cavity with a liquid conductive material includes: filling and solidifying the liquid conductive material in the groove before forming the second adhesive layer.

[0018] In one specific embodiment of the fourth aspect of this disclosure, the operating temperature for filling the groove or channel with liquid conductive material is higher than the melting point of the liquid conductive material; after the liquid conductive material solidifies and before the second adhesive layer is formed, the operating temperature is lower than the melting point of the liquid conductive material.

[0019] In one specific embodiment of the fourth aspect of this disclosure, the filling of the groove or channel with liquid conductive material is carried out in oxygen.

[0020] In one specific embodiment of the fourth aspect of this disclosure, forming a first adhesive layer on a carrier plate includes: coating an adhesive solution onto the carrier plate; and using a semi-cured adhesive solution to form the first adhesive layer.

[0021] In one specific embodiment of the fourth aspect of this disclosure, the moisture content of the first adhesive layer is 30%-50%. The first adhesive layer is not fully cured and still contains a certain amount of water. This facilitates the reaction between the water in the first adhesive layer and the liquid conductive material in subsequent processes, oxidizing the surface of the liquid conductive material. Simultaneously, the incomplete curing of the first adhesive layer also reduces the interfacial stress between the second adhesive layer and the first adhesive layer subsequently formed on top of the first adhesive layer, resulting in a tighter bond between the two layers. Attached Figure Description

[0022] Figure 1 This is a cross-sectional schematic diagram of a conductive structure provided in at least one embodiment of the present disclosure.

[0023] Figure 1a This is a cross-sectional schematic diagram of a conductive structure provided in at least one embodiment of the present disclosure.

[0024] Figure 2 This is a cross-sectional schematic diagram of a display panel provided in at least one embodiment of the present disclosure.

[0025] Figure 3 This is a schematic diagram of a flexible circuit board provided in at least one embodiment of the present disclosure.

[0026] Figure 4 This is a schematic flowchart of a method for preparing a conductive structure according to at least one embodiment of the present disclosure.

[0027] Figure 5 This is a schematic flowchart of a method for preparing a conductive structure according to at least one embodiment of the present disclosure.

[0028] Figure 6 This is a schematic diagram of an intermediate structure of a conductive structure provided in at least one embodiment of the present disclosure.

[0029] Figure 7 This is a schematic diagram of an intermediate structure of a conductive structure provided in at least one embodiment of the present disclosure.

[0030] Figure 8 This is a schematic diagram of an intermediate structure of a conductive structure provided in at least one embodiment of the present disclosure.

[0031] Figure 9 This is a schematic diagram of an intermediate structure of a conductive structure provided in at least one embodiment of the present disclosure.

[0032] Figure 10 This is a schematic diagram of an intermediate structure of a conductive structure provided in at least one embodiment of the present disclosure.

[0033] Figure 11 This is a schematic diagram of an intermediate structure of a conductive structure provided in at least one embodiment of the present disclosure.

[0034] Figure 12 This is a schematic flowchart of a method for preparing a conductive structure according to at least one embodiment of the present disclosure.

[0035] Figure 13 This is a schematic diagram of an intermediate structure of a conductive structure provided in at least one embodiment of the present disclosure.

[0036] Figure 14 This is a schematic diagram of an intermediate structure of a conductive structure provided in at least one embodiment of the present disclosure.

[0037] Figure 15 This is a schematic diagram of an intermediate structure of a conductive structure provided in at least one embodiment of the present disclosure.

[0038] Explanation of icon numbers:

[0039] Conductive structure 10; flexible insulating layer 11, receiving cavity 111; conductive unit 12; bonding layer 13; carrier plate 101; first adhesive layer 102; photoresist layer 103; liquid conductive material 104; metal oxide 105; second adhesive layer 106; through groove 107; groove 108; display panel 20; display area 21, bending area 22, bonding area 23; flexible circuit board 30; bonding area 31, bending area 32, component area 33. Detailed Implementation

[0040] The technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. Based on the embodiments of this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0041] Through long-term research, the inventors discovered that flexible displays or flexible circuit boards typically consist of metal conductors (such as copper or titanium-aluminum alloys) and a flexible substrate (such as polyimide plastic), which are bonded together using processes such as bonding or lamination. However, the metal conductors and the flexible substrate have different degrees of flexibility; the elastic modulus of the metal conductors is much greater than that of the flexible substrate. Therefore, the compatibility between the metal conductors and the flexible substrate is poor. Furthermore, because the elastic modulus of the metal conductors is high and they are prone to breakage, the flexible circuit boards composed of metal conductors and flexible substrates have poor flexibility.

[0042] In view of the above, at least one embodiment of this disclosure provides a conductive structure, which includes a flexible insulating layer, a conductive unit, and a bonding layer. The flexible insulating layer includes a receiving cavity. The conductive unit includes a liquid conductive material and is filled in the receiving cavity. The bonding layer is located on the side of the flexible insulating layer facing the conductive unit. The conductive structure in this disclosure uses a liquid conductive material as the conductive unit. This conductive unit is liquid in its use state and has no elastic modulus, which can greatly improve the flexibility of the conductive structure. Furthermore, the conductive unit and the flexible insulating layer are connected through the bonding layer. When the conductive structure is bent, the conductive unit deforms with the flexible insulating layer, which can ensure the continuity of the liquid conductive material in the cavity of the flexible insulating layer and avoid the interruption of the liquid conductive material when the conductive structure is bent, thereby ensuring the stability of the electrical connection.

[0043] Below, in conjunction with the appendix Figure 1The conductive structure according to at least one embodiment of the present disclosure will be described. Furthermore, as shown in the accompanying drawings, in at least one embodiment of the present disclosure, a spatial Cartesian coordinate system is established with the plane containing the conductive structure as a reference to define the positions of the conductive structure and even the individual elements within it. In this spatial Cartesian coordinate system, the X-axis and Y-axis are parallel to the plane containing the conductive structure, and the Z-axis is perpendicular to the plane containing the conductive structure.

[0044] Figure 1 This is a cross-sectional schematic diagram of a conductive structure provided in at least one embodiment of this disclosure. For example... Figure 1 As shown, the conductive structure 10 includes a flexible insulating layer 11, a conductive unit 12, and a bonding layer 13.

[0045] The flexible insulating layer 11 includes a receiving cavity 111. This receiving cavity 111 is used to contain a liquid conductive material. Specifically, the orthographic projection of the receiving cavity 111 onto the plane containing the X and Y axes forms a predetermined linear pattern. Figure 1 In this example, the orthographic projection of the cavity 111 onto the plane containing the X and Z axes is taken as a rectangle. In reality, the cross-section of the cavity 111 can also be a circle, an ellipse, a triangle, a polygon, or other shapes.

[0046] In at least one embodiment of at least one embodiment of this disclosure, the cross-section of the receiving cavity 111 can be star-shaped, such as a triangular star, a quadrilateral star, a pentagonal star, etc., to increase the area of ​​the sidewall of the receiving cavity 111, thereby increasing the surface area of ​​the bonding layer 13, so as to improve the bonding performance between the flexible insulating material and the conductive unit 12.

[0047] The flexible insulating layer 11 is made of hydroxyl groups, the bonding layer 13 is made of hydroxyl groups and metal oxides, and the liquid conductive material has the same metal ions as the metal oxides.

[0048] Specifically, the flexible insulating layer 11 is made of a hydrophilic adhesive containing hydroxyl groups. The hydrophilic adhesive is hydrophilic; for example, it can be a hydrogel. Furthermore, the hydrophilic adhesive in this embodiment exhibits excellent flexibility after curing; for example, it can be a topological hydrogel, a double-network structure hydrogel, or a composite hydrogel. Hydrogels have an elastic modulus of 1~100 kPa and excellent flexibility; the use of a hydrogel for the flexible insulating layer 11 can improve the flexibility of the conductive structure 10.

[0049] The conductive unit 12 comprises a liquid conductive material and is filled in the receiving cavity 111. Specifically, the liquid conductive material can be a conductive material that is liquid at room temperature. The liquid conductive material can include liquid metals or low-melting-point metals. For example, the liquid conductive material can be one or a combination of mercury, gallium, gallium-indium alloys, gallium-indium-tin alloys, transition metals, doped gallium-indium alloys, and doped gallium-indium-tin alloys. Specifically, the liquid conductive material is indium gallium eutectic (EGAIn). Indium gallium eutectic is a conductive liquid metal. Indium gallium eutectic consists of 75.5% gallium and 24.5% indium. The resistivity of indium gallium eutectic EGAIn is approximately 29.4 × 10⁻⁶ W⁻cm. This low-viscosity liquid is easy to mold and suitable for various electronic applications.

[0050] In at least one embodiment of at least one embodiment of this disclosure, the conductive unit 12 may include a wire, wherein the linewidth of the wire may be 0.2 micrometers to 10 micrometers, for example, the linewidth of the wire may be 0.5 micrometers, 1 micrometer, or 2 micrometers. Optionally, the thickness of the flexible insulating layer 11 is 2 micrometers to 10 micrometers, and the thickness of the conductive unit 12 is 1 micrometer to 5 micrometers. Specifically, in this disclosure, the thickness of the flexible insulating layer 11 refers to the thickness of the flexible insulating layer 11 in the region of the conductive structure 10 where the conductive unit 12 is not disposed. In the region of the conductive structure 10 where the conductive unit 12 is disposed, along the thickness direction of the conductive structure 10, the distance from the side of the conductive unit 12 facing the upper surface of the flexible insulating layer 11 to the upper surface of the flexible insulating layer 11 is approximately 0.5 micrometers to 1 micrometer.

[0051] In at least one embodiment of at least one embodiment of this disclosure, the conductive unit 12 occupies 20% to 70% of the total volume of the conductive structure 10. For example, the height positions of the two conductive units 12 can be the same, that is, the two conductive units 12 are almost on the same layer, see [reference]. Figure 1 Optionally, the height positions of the multiple conductive units 12 in the conductive structure 10 can be different. For example, the multiple conductive units 12 can be stacked, see [reference needed]. Figure 1a The stacking of multiple conductive units 12 can increase the volume ratio of the conductive unit 12 to the entire conductive structure 10, thereby improving the integration of the conductive structure 10.

[0052] The conductive structure 10 in this disclosure uses a liquid conductive material as the conductive unit 12. The conductive unit 12 is a liquid in the use state and has no elastic modulus, which can greatly improve the flexibility of the conductive structure 10.

[0053] The bonding layer 13 is located on the side of the flexible insulating layer 11 facing the conductive unit 12 and covers the conductive unit 12. Specifically, the flexible insulating layer 11 is made of hydroxyl groups, and the bonding layer 13 is made of hydroxyl groups and metal oxides, wherein the metal ions of the metal oxides are the same as those of the liquid conductive material.

[0054] In at least one embodiment of at least one example of this disclosure, gallium indium tin alloy is used as the liquid conductive material. Gallium indium tin alloy has a melting point of 12 degrees Celsius and good thermal conductivity. The surface of gallium indium tin alloy slowly oxidizes upon contact with water, forming gallium oxide. During the formation of the conductive structure 10, the flexible insulating layer 11 is an incompletely cured hydrogel. The liquid conductive material comes into contact with water in the incompletely cured hydrogel on the sidewall of the receiving cavity 111 to form gallium oxide. The gallium oxide further bonds with hydroxyl groups in the hydrogel to form a bonding layer 13. For example, the bonding of gallium oxide and hydroxyl groups can be through chemical bonds or hydrogen bonds. That is, the bonding layer 13 includes hydrogen bonds or chemical bonds formed by the bonding of gallium oxide and hydroxyl groups.

[0055] In this disclosure, the liquid conductive unit 12 and the flexible insulating layer 11 are connected by a bonding layer 13. When the conductive structure 10 is bent, the conductive unit 12 deforms with the flexible insulating layer 11 and will not break mechanically, which can improve the reliability of the conductive structure 10.

[0056] In electronic devices, the display panel 20 is bonded to a flexible circuit board 30 that is electrically connected to the motherboard, thereby electrically connecting the display panel 20 and the motherboard of the electronic device. At least a portion of the display panel 20 or the flexible circuit board 30 needs to be bent towards the backlight side of the display panel 20. To improve the flexibility of the display panel 20 or the flexible circuit board 30, the conductive structure 10 described in the above embodiments can be applied to the display panel 20 or the flexible circuit board 30.

[0057] At least one embodiment of this disclosure provides a display panel 20, wherein the conductive structure 10 is located at least in the bending region of the display panel 20. The following is a description of the accompanying drawings. Figure 2 The scheme of applying the conductive structure 10 to the display panel 20 will be described.

[0058] like Figure 2 As shown, the display panel 20 includes a display area 21, a bending area 22, and a bonding area 23, with the bending area 22 located between the display area 21 and the bonding area 23. The display panel 20 also includes signal lines extending from the display area 21 to the bonding area 23. These signal lines may be located in at least one film layer of the display panel 20; for example, the signal lines may be data lines, scan signal lines, power signal lines, gate signal lines, etc., within the display panel 20. The portion of the signal line located in the bending area 22 is a conductive unit 12 in the conductive structure 10.

[0059] In at least one embodiment of this disclosure, at least a portion of the film layer of the display panel 20 located in the bending region 22 may include, for example: Figure 1The conductive structure 10 is shown. For example, a portion of the thin-film transistor (TFT) layer of the display panel 20 is the conductive structure 10 in the above embodiment. The conductive unit 12 in the conductive structure 10 can be used as a signal line in the display panel 20. Alternatively, the conductive unit 12 in the conductive structure 10 can be other structures in the display panel 20, such as resistors or capacitors.

[0060] The display panel and the conductive structure provided in the embodiments of this disclosure belong to the same inventive concept. Details not described in detail in the embodiments of the display panel can be found in the embodiments of the conductive structure, and will not be repeated here.

[0061] At least one embodiment of this disclosure provides a flexible circuit board, wherein the conductive structure is located at least in the bending region of the flexible circuit board. The following is a description of the accompanying drawings. Figure 3 The solution for applying conductive structures to flexible circuit boards is explained.

[0062] like Figure 3 As shown, the flexible circuit board 30 includes a component area 33, a bending area 32, and a bonding area 31. The component area 33 of the flexible circuit board 30 is connected to electronic components such as capacitors or resistors. The bonding area 31 is used for bonding with the non-display area of ​​the display panel 20. The bending area 32 is located between the component area 33 and the bonding area 31. The flexible circuit board 30 also includes signal lines extending from the component area 33 to the bonding area 31. The portion of the flexible circuit board 30 located in the bending area 32 may include, for example... Figure 1 The conductive structure 10 shown can be a conductive unit 12 in the conductive structure 10, and the portion of the signal line located in the bending region 32 can be a conductive unit 12 in the conductive structure 10.

[0063] The flexible circuit board provided in the embodiments of this disclosure and the conductive structure provided in the embodiments of this disclosure belong to the same inventive concept. Details not described in detail in the embodiments of the flexible circuit board can be found in the embodiments of the conductive structure, and will not be repeated here.

[0064] At least one embodiment of this disclosure provides a display device, which may include the display panel 20 or flexible circuit board 30 described in the above embodiments. Further, the display device may also include electronic components such as a control device, a camera device, and a battery. Specifically, the display device may be an electronic product such as a smartphone, computer monitor, game console, or television.

[0065] This disclosure provides at least one embodiment of a method for preparing a flexible conductive structure, which is described below in conjunction with the appendix. Figures 4-11 The preparation method of the conductive structure is explained.

[0066] like Figure 4As shown, the method for preparing a conductive structure provided in at least one embodiment of this disclosure includes the following steps S100~S200.

[0067] S100: A carrier plate is provided, and a flexible insulating layer is formed on the carrier plate. A receiving cavity is formed in the flexible insulating layer.

[0068] S200: The cavity is filled with liquid conductive material.

[0069] The flexible insulating layer may include a first adhesive layer and a second adhesive layer, which together form at least one cavity for accommodating a liquid conductive material. The first adhesive layer may have different shapes; optionally, the surface of the first adhesive layer may be planar or have grooves formed on its surface. (The following is a related description...) Figures 5-11 The preparation method of the first adhesive layer with a planar surface is described, and combined with... Figures 12-15 The preparation method of the first adhesive layer with grooves on its surface is described.

[0070] Specifically, such as Figure 5 As shown, when the surface of the first adhesive layer is planar, the method for preparing the conductive structure provided in at least one embodiment of this disclosure includes the following steps S510 to S560.

[0071] S510: Provides a carrier board. Specifically, such as... Figure 6 As shown, the carrier plate 101 can be an inorganic material with good chemical stability, such as glass, diamond, or silicon. In at least one embodiment, the carrier plate 101 can be the display panel 20 or an intermediate structure of the display panel 20.

[0072] After providing the carrier plate 101, a first adhesive layer needs to be formed on the carrier plate 101. The specific steps are S520 and S530.

[0073] S520: Coating a colloidal solution onto a carrier plate.

[0074] Specifically, such as Figure 7 As shown, the colloidal solution can be applied to the carrier plate 101 using processes such as spin coating, blade coating, or spray coating. The colloidal solution contains hydroxyl groups; for example, it can be a hydrophilic hydrogel. After coating, the colloidal solution uniformly covers the carrier plate 101.

[0075] S530: Semi-cured colloidal solution to form the first adhesive layer.

[0076] Specifically, the curing method can be adapted to the type of colloidal solution; for example, light curing or heat curing processes can be used. For instance, the carrier plate 101 can be placed in a drying device to semi-cure the colloidal solution.

[0077] In at least one embodiment, the moisture content of the first adhesive layer 102 after semi-curing is 30%-50%. That is, the first adhesive layer 102 is not fully cured and still contains a certain amount of water. This facilitates the reaction between the water in the first adhesive layer 102 and the liquid conductive material 104 in subsequent processes, oxidizing the surface of the liquid conductive material 104. Simultaneously, the incomplete curing of the first adhesive layer 102 also reduces the interfacial stress between the second adhesive layer 106 and the first adhesive layer 102 subsequently formed on the first adhesive layer 102, resulting in a tighter bond between the second adhesive layer 106 and the first adhesive layer 102.

[0078] When the surface of the first adhesive layer 102 is planar, filling the cavity with liquid conductive material includes the following steps S540 to S550.

[0079] S540: A patterned photoresist layer is formed on the side of the first resist layer facing away from the substrate. The photoresist layer includes a through-hole, the bottom of which exposes the first resist layer.

[0080] Specifically, such as Figure 8 As shown, photoresist is applied to the side of the first adhesive layer 102 facing away from the carrier plate 101. A patterned photomask is used to expose and develop the photoresist to solidify a portion of the photoresist, thereby forming a patterned photoresist layer 103. A through-groove 107 is formed in the photoresist layer 103, with the bottom of the through-groove 107 exposing the first adhesive layer 102, so that the liquid conductive material 104 subsequently filled in the through-groove 107 can contact the first adhesive layer 102.

[0081] S550: Fill and solidify liquid conductive material in a through-slot.

[0082] Specifically, such as Figure 9 As shown, the carrier plate 101 is first placed in an environment with a temperature higher than the melting point of the liquid conductive material 104, for example, the carrier plate 101 is placed on a heating platform. Taking the liquid conductive material 104 as a gallium indium tin alloy as an example, the melting point of gallium indium tin is 12°C, and the operating temperature can be 20°C to 40°C.

[0083] In at least one embodiment, the filling of the through-channel 107 with liquid conductive material 104 is carried out in oxygen. This method can accelerate the oxidation of the surface of the liquid conductive material 104 to form a metal oxide 105, such as gallium oxide. Further, the metal oxide at the interface between the liquid conductive material 104 and the first adhesive layer 102 and the hydroxyl groups in the first adhesive layer 102 combine to form a bonding layer 13.

[0084] After filling with liquid conductive material 104, the operating temperature is lowered to below the melting point of liquid conductive material 104. Taking gallium indium tin alloy as an example, the operating temperature can be 0℃~10℃.

[0085] S560: Remove the photoresist layer.

[0086] Specifically, such as Figure 10 As shown, the photoresist layer 103 is dissolved using a stripping solution or mechanically stripped. During the removal of the photoresist layer 103, the operating temperature can be maintained at 0℃~10℃ to prevent the liquid conductive material 104 from melting and leaking out.

[0087] S570: A second adhesive layer is formed on the side of the first adhesive layer away from the carrier plate.

[0088] Specifically, a second adhesive layer 106 is formed on the side of the solidified liquid conductive material 104 facing away from the carrier plate 101. The second adhesive layer 106 covers the first adhesive layer 102 and the liquid conductive material 104, and the second adhesive layer 106 covers the through groove 107 to form a receiving cavity 111.

[0089] Specifically, such as Figure 11 As shown, a colloidal solution can be applied to the first adhesive layer 102 using processes such as spin coating, blade coating, or spray coating. For example, the colloidal solution can be a hydrophilic hydrogel. A bonding layer 13 is formed at the interface between the second adhesive layer 106 and the metal oxide 105 of the liquid conductive material 104.

[0090] The remaining portions of the first adhesive layer 102 and the second adhesive layer 106 together constitute the flexible insulating layer 11. In at least one embodiment, the second adhesive layer 106 and the first adhesive layer 102 are made of the same material, and since the first adhesive layer 102 was not fully cured in the previous steps, the interfacial stress between the second adhesive layer 106 and the first adhesive layer 102 is relatively small, allowing the second adhesive layer 106 and the first adhesive layer 102 to bond well.

[0091] After applying the colloidal solution, the first adhesive layer 102 and the second adhesive layer 106 are cured simultaneously. This avoids the formation of large interfacial stress between the first adhesive layer 102 and the second adhesive layer 106, prevents gaps or peeling between the first adhesive layer 102 and the second adhesive layer 106, and thus prevents leakage of the liquid conductive material 104, ensuring the reliability of the conductive structure 10.

[0092] Specifically, such as Figure 12 As shown, when the surface of the first adhesive layer 102 is provided with grooves, the difference between at least one embodiment of this disclosure and the above preparation method is that the surface of the first adhesive layer 102 is provided with grooves, and liquid conductive material is directly filled and solidified in the grooves.

[0093] When a groove is provided on the surface of the first adhesive layer, the method for preparing the conductive structure provided in at least one embodiment of the present disclosure includes the following steps S1210 to S1240.

[0094] Step S1210: Provide a carrier board.

[0095] Specifically, you can refer to Figure 6 Step S510 will not be repeated here.

[0096] Step S1220: Form the first adhesive layer on the carrier plate.

[0097] Specifically, such as Figure 13 As shown, the first adhesive layer 102 includes a groove 108. Optionally, the groove 108 can be formed on the surface of the first adhesive layer 102 by etching after the first adhesive layer 102 with a planar surface is formed; alternatively, a mold can be used to solidify the liquid colloidal solution into a first adhesive layer 102 with the groove 108 on the surface.

[0098] Step S1230: Fill and solidify the groove with liquid conductive material.

[0099] Specifically, a cross-sectional schematic diagram of the liquid conductive material 104 filling the groove 108 is shown below. Figure 14 As shown, the bottom surface of the liquid conductive material 104 contacts the bottom surface of the groove 108, and the side surface of the liquid conductive material 104 contacts the inner wall of the groove 108, forming a bonding layer 13. Specific process details can be found in step S550 and will not be repeated here.

[0100] Step S1240: A second adhesive layer is formed on the side of the first adhesive layer away from the carrier plate.

[0101] Specifically, such as Figure 15 As shown, the second adhesive layer 106 covers the first adhesive layer 102 and the side of the liquid conductive material facing away from the carrier plate 101. The upper surface of the liquid conductive material contacts the second adhesive layer 106 to form a bonding layer 13. The first adhesive layer 102 and the second adhesive layer 106 together form a receiving cavity 111. The specific process can be referred to step S570, and will not be repeated here.

[0102] This disclosure uses liquid conductive material 104 to form conductive unit 12. Since the elastic modulus of liquid is almost negligible, the flexibility of conductive structure 10 can be improved.

[0103] In this disclosure, the first adhesive layer 102 and the second adhesive layer 106 respectively form a bonding layer 13 with the contact portion of the liquid conductive material 104. This increases the bonding force between the liquid conductive material 104 and the flexible insulating layer 11 composed of the first adhesive layer 102 and the second adhesive layer 106, preventing the conductive unit 12 and the flexible insulating layer 11 from peeling off during bending, thus ensuring the reliability of the conductive structure 10. Furthermore, the bonding layer 13 also ensures the continuity of the liquid conductive material 104 within the receiving cavity 111 of the flexible insulating layer 11, preventing the conductive unit 12 composed of the liquid conductive material 104 from being interrupted when the conductive structure 10 is bent, thereby ensuring the stability of the electrical connection.

[0104] Furthermore, the method for preparing the conductive structure 10 provided in at least one embodiment of this disclosure further includes peeling off the carrier plate 101 to obtain the conductive structure 10.

[0105] The method for preparing the conductive structure according to the embodiments of this disclosure and the conductive structure provided in the embodiments of this disclosure belong to the same inventive concept. Details not described in detail in the embodiments of the method for preparing the conductive structure can be found in the embodiments section of the conductive structure, and will not be repeated here.

[0106] The above description is merely a preferred embodiment of this disclosure and is not intended to limit this disclosure. Any modifications or equivalent substitutions made within the spirit and principles of this disclosure should be included within the scope of protection of this disclosure.

Claims

1. A conductive structure, characterized in that, include: Flexible insulating layer, including a receiving cavity; The conductive unit is made of liquid conductive material and is filled in the receiving cavity; as well as A bonding layer is located on the side of the flexible insulating layer facing the conductive unit and covers the conductive unit; The flexible insulating layer includes a first adhesive layer and a second adhesive layer. The surface of the first adhesive layer is provided with a groove. The first adhesive layer and the second adhesive layer form at least one receiving cavity for accommodating the liquid conductive material. The bonding layer is formed by the combination of a metal oxide at the interface between the liquid conductive material and the first adhesive layer and hydroxyl groups in the first adhesive layer. The metal oxide is formed by the reaction of water in the first adhesive layer with the liquid conductive material, thereby oxidizing the surface of the liquid conductive material.

2. The conductive structure according to claim 1, characterized in that, The flexible insulating layer is made of hydroxyl groups, the bonding layer is made of the hydroxyl groups and metal oxides, and the liquid conductive material has the same metal ions as the metal oxides.

3. The conductive structure according to claim 1, characterized in that, The liquid conductive material is a liquid metal.

4. The conductive structure according to claim 1, characterized in that, The flexible insulating layer is a hydrophilic adhesive containing hydroxyl groups, and the thickness of the flexible insulating layer is 2 micrometers to 10 micrometers, while the thickness of the conductive unit is 1 micrometer to 5 micrometers.

5. The conductive structure according to any one of claims 1-4, characterized in that, The conductive unit includes a wire.

6. A display panel, characterized in that, The display panel includes a display area, a bending area, and a bonding area, wherein the bending area is located between the display area and the bonding area, and the display panel further includes: The signal line extends from the display area to the bonding area; Wherein, the portion of the display panel located in the bending area includes a conductive structure as described in any one of claims 1-5, and the portion of the signal line located in the bending area is the conductive unit in the conductive structure.

7. A flexible circuit board, characterized in that, The flexible circuit board includes a component area, a bending area, and a bonding area, wherein the bending area is located between the component area and the bonding area. The flexible circuit board also includes: Signal lines extend from the component area to the bonding area; Wherein, the portion of the flexible circuit board located in the bending area includes a conductive structure as described in any one of claims 1-5, and the portion of the signal line located in the bending area is a conductive unit in the conductive structure.

8. A method for preparing a conductive structure, characterized in that, include: A carrier plate is provided, and a flexible insulating layer is formed on the carrier plate, wherein a receiving cavity is formed in the flexible insulating layer; as well as The cavity is filled with a liquid conductive material; The surface of the liquid conductive material is oxidized, and a portion of the surface of the liquid conductive material is bonded to the surface portion of the flexible insulating layer facing the liquid conductive material to form a bonding layer, while the remaining portion of the liquid conductive material forms a conductive unit. The formation of the flexible insulating layer on the carrier plate includes: A first adhesive layer is formed on the carrier plate; A second adhesive layer is formed on the side of the first adhesive layer that is away from the carrier plate; The process of filling the cavity with liquid conductive material includes: before forming the second adhesive layer, forming a patterned photoresist layer on the side of the first adhesive layer away from the carrier plate, the photoresist layer including a through groove, the bottom of the through groove exposing the first adhesive layer; The channel is filled with and solidified with liquid conductive material; and Remove the photoresist layer.

9. The method for preparing the conductive structure according to claim 8, characterized in that, The formation of the flexible insulating layer on the carrier plate includes: A first adhesive layer is formed on the carrier plate, the first adhesive layer including grooves; and A second adhesive layer is formed on the side of the first adhesive layer that is away from the carrier plate; The process of filling the cavity with liquid conductive material includes filling and solidifying the groove with liquid conductive material before forming the second adhesive layer.

10. The method for preparing the conductive structure according to claim 9, characterized in that, The operating temperature for filling the groove or channel with liquid conductive material is higher than the melting point of the liquid conductive material; after the liquid conductive material solidifies and before the second adhesive layer is formed, the operating temperature is lower than the melting point of the liquid conductive material.

11. The method for preparing the conductive structure according to claim 9, characterized in that, The filling of the groove or the through-slot with liquid conductive material is carried out in oxygen.

12. The method for preparing the conductive structure according to claim 8 or 9, characterized in that, The formation of the first adhesive layer on the carrier plate includes: Coating the carrier plate with a colloidal solution; and The colloidal solution is semi-cured to form the first adhesive layer.

13. The method for preparing the conductive structure according to claim 8 or 9, characterized in that, The moisture content of the first adhesive layer is 30%-50%.

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