Foldable electronic device

Abstract

A conductive layer stack structure and a foldable electronic device, the conductive layer stack structure comprises a conductive layer and a thickening layer, the conductive layer extends along a first direction. The thickening layer is located above or below the conductive layer. When the conductive layer stack structure is bent 180° perpendicularly or parallel to the first direction with a curvature radius R=3 mm, it can withstand more than 40,000 folding times without breaking.

Description

Technical Field

[0001] The present disclosure relates to a conductive layer stack, and more particularly to a conductive layer stack used in routing of a foldable electronic device. Background Art

[0002] Electronic components are constantly moving towards miniaturization and high-speed development. Among them, flexible electronic technology that can maintain high performance and make electronic components flexible is the most anticipated new technology of the next generation, including flexible panels, displays, batteries, wearable electronic devices, etc.

[0003] However, in a foldable electronic device, the wiring at the bend may be easily broken after being bent multiple times, thereby affecting signal transmission and affecting the performance of the foldable electronic device. Summary of the invention

[0004] In view of the above problems, the present disclosure aims to provide a conductive layer stack structure with a thickened layer to improve the bending resistance of a foldable electronic device.

[0005] Some embodiments of the present disclosure provide a conductive layer stack structure, comprising a conductive layer and a thickening layer. The conductive layer extends along a first direction. The thickening layer is located above or below the conductive layer, and the conductive layer stack structure can withstand more than 40,000 folds without breaking when bent 180° perpendicularly or parallel to the first extension direction with a radius of curvature R=3 mm.

[0006] In some embodiments, a length of the thickened layer in the first direction is greater than 9 mm and does not exceed a length of the conductive layer extending along the first direction.

[0007] In some embodiments, a length of the thickened layer in the first direction is greater than 15 mm and does not exceed a length of the conductive layer extending along the first direction.

[0008] In some embodiments, the angle between the bending axis of the conductive layer stack and two ends of the thickened layer is 180° to 360°.

[0009] In some embodiments, the thickened layer increases the stress strain of the conductive layer stack when it is bent by 0.1 to 10%, and reduces the curvature radius of the conductive layer stack by 0.5 to 3 mm.

[0010] In some embodiments, the thickened layer is located on the stress tensile side when the conductive layer stack is bent.

[0011] In some embodiments, a foldable electronic device is provided, which includes the conductive layer stack structure described in the above and following embodiments or examples.

[0012] Some embodiments of the present disclosure provide a foldable electronic device, comprising a display area and a non-display area. The non-display area is located outside the display area, wherein the non-display area has a plurality of traces extending along a first direction, and each of the plurality of traces comprises: a substrate and a conductive layer located above the substrate. The non-display area has a local thickening region, which comprises a bending portion of the foldable electronic device, and each of the plurality of traces in the local thickening region further comprises a thickening layer, which is above or below the conductive layer and is located on the stress stretching side when the foldable electronic device is bent.

[0013] In some embodiments, in a foldable electronic device, the width of the local thickened region extends along a second direction perpendicular to the first direction, and a width of one of the traces is W. 1 , the spacing between these traces is P 1 The number of these traces is N, and the width of the local thickening area ranges from W 1 To (W 1 +P 1 )x N.

[0014] In some embodiments, in the foldable electronic device, a length of the thickened layer along the first direction is greater than 3 mm.

[0015] In some embodiments, in a foldable electronic device, the thickened layer is formed of a metal material, and a ratio of a thickness of the thickened layer to a thickness of the conductive layer is about 0.05-5.

[0016] In some embodiments, in a foldable electronic device, the thickened layer is formed of a non-metallic material or a composite conductive material, and a ratio of the thickness of the thickened layer to the thickness of the conductive layer is about 0.1-50.

[0017] In some embodiments, in a foldable electronic device, the thickened layer is formed of a metal material, and the value of the thickness of the substrate multiplied by the Young's modulus of the substrate is about 100 to 300, the value of the thickness of the conductive layer multiplied by the Young's modulus of the conductive layer is about 20 to 70, and the value of the thickness of the thickened layer multiplied by the Young's modulus is about 5 to 30.

[0018] In some embodiments, in a foldable electronic device, the thickening layer is formed of a non-metallic material or a composite conductive material, and the value of the thickness of the substrate multiplied by the Young's modulus of the substrate is approximately 100 to 300, the value of the thickness of the conductive layer multiplied by the Young's modulus of the conductive layer is approximately 20 to 70, and the value of the thickness of the thickening layer multiplied by the Young's modulus of the thickening layer is approximately 2 to 60.

[0019] In some embodiments, in a foldable electronic device, the thickened layer includes: a first polymer layer and a second polymer layer. The second polymer layer is above the first polymer layer, wherein a material of the first polymer layer is different from a material of the second polymer layer.

[0020] In some embodiments, in the foldable electronic device, the ratio of the Young's modulus of the first polymer layer to the Young's modulus of the second polymer layer is about 10 3 ~10 6 .

[0021] In some embodiments, in a foldable electronic device, a ratio of the thickness of the first polymer to the thickness of the conductive layer is about 30-100, a ratio of the thickness of the second polymer to the thickness of the conductive layer is about 30-100, and a ratio of the thickness of the first polymer to the thickness of the second polymer is about 0.5-2. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The present disclosure can be best understood from the following detailed description and read in conjunction with the accompanying drawings. It is emphasized that, in accordance with standard practice in the industry, various features are not drawn to scale and are only used for illustration purposes. In fact, for the sake of clarity of discussion, various features may be arbitrarily increased or reduced.

[0023] Figure 1A is a schematic diagram of a panel according to some embodiments of the present disclosure;

[0024] Figures 1B to 1D is a partial cross-sectional view of a routing according to some embodiments of the present disclosure;

[0025] Figure 1E for Figure 1A A partial enlarged view of region 114 of the panel;

[0026] Figure 2A and Figure 2B is a schematic diagram of a conductive layer stack in a bent state;

[0027] Figure 3A and Figure 3B A schematic diagram of a conductive layer stack structure of a comparative example in a bent state and a non-bent state;

[0028] FIG. 4A to FIG. 4C They are respectively conductive layer stacking structures according to some experimental examples;

[0029] FIG. 5A to FIG. 5D is a schematic diagram of a configuration of a conductive layer stack according to some embodiments;

[0030] Fig. 6A and Figure 6B is a schematic diagram of a conductive layer stack structure in a bent state and an unfolded state according to some embodiments;

[0031] Figure 6C and Fig.6Dis a schematic diagram of a conductive layer stack structure in a bent state and an unfolded state according to some embodiments;

[0032] Fig. 6E and Fig. 6F is a schematic diagram of a conductive layer stack structure in a bent state and an unfolded state according to some embodiments;

[0033] Fig. 7A and Figure 7B is a schematic diagram of a conductive layer stack structure in a bent state and an unfolded state according to some embodiments;

[0034] Figure 7C and Fig.7D is a schematic diagram of a conductive layer stack structure in a bent state and an unfolded state according to some embodiments;

[0035] Fig. 7E and Figure 7F is a schematic diagram of a conductive layer stack structure in a bent state and an unfolded state according to some embodiments;

[0036] FIG. 8A to FIG. 8I are cross-sectional views of a foldable electronic device at different intermediate stages in a manufacturing process according to some embodiments of the present disclosure;

[0037] FIG. 9A to FIG. 9J are cross-sectional views of a foldable electronic device at different intermediate stages in a manufacturing process according to some embodiments of the present disclosure;

[0038] FIG. 10A to FIG. 10G are cross-sectional views of a foldable electronic device at different intermediate stages in a manufacturing process according to some embodiments of the present disclosure;

[0039] FIG. 11A to FIG. 11H are cross-sectional views of a foldable electronic device at different intermediate stages in a manufacturing process according to some embodiments of the present disclosure;

[0040] FIG. 12A to FIG. 12H sectional views of a foldable electronic device at different intermediate stages in the manufacturing process according to some embodiments of the present disclosure.

[0041]

Explanation of symbols

[0042] 20: Conductive layer stacking

[0043] 22:Substrate

[0044] 24: Routing material layer

[0045] 26: Thickening layer

[0046] 30: Conductive layer stacking structure

[0047] 32:Substrate

[0048] 34: routing material layer

[0049] 36: Thickening layer

[0050] 40: Conductive layer stacking structure

[0051] 42:Substrate

[0052] 44:Metal layer

[0053] 50: Conductive layer stacking structure

[0054] 52:Substrate

[0055] 54: Conductive layer

[0056] 56:Metal layer

[0057] 58: Thickening layer

[0058] 60: Conductive layer stacking structure

[0059] 62:Substrate

[0060] 64: Conductive layer

[0061] 66:Metal layer

[0062] 68: Thickening layer

[0063] 70: Conductive layer stacking structure

[0064] 72:Substrate

[0065] 74: Conductive layer

[0066] 76:Metal layer

[0067] 78: first polymer layer

[0068] 80: Second polymer layer

[0069] 100: Panel

[0070] 110: Routing

[0071] 112, 114, 116: Area

[0072] 120: Conductive layer stacking structure

[0073] 122:Substrate

[0074] 124:Metal layer

[0075] 126: Thickening layer

[0076] 128: Conductive layer

[0077] 130: Conductive layer stacking structure

[0078] 132:Substrate

[0079] 134: Conductive layer

[0080] 136:Metal layer

[0081] 138: Thickening layer

[0082] 140: Conductive layer stacking structure

[0083] 142:Substrate

[0084] 144:Metal layer

[0085] 146: Conductive layer

[0086] 148: Thickening layer

[0087] 210: Conductive layer stacking structure

[0088] 212:Substrate

[0089] 214: routing material layer

[0090] 216: Thickening layer

[0091] 220: Conductive layer stacking structure

[0092] 222:Substrate

[0093] 224: routing material layer

[0094] 226: first polymer layer

[0095] 228: Second polymer layer

[0096] 230: Conductive layer stacking structure

[0097] 232:Substrate

[0098] 234: Catalyst layer

[0099] 236: Conductive layer

[0100] 238: Thickening layer

[0101] 240: Conductive layer stacking structure

[0102] 242:Substrate

[0103] 244: Catalyst layer

[0104] 246: Conductive layer

[0105] 248: first polymer layer

[0106] 250: Second polymer layer

[0107] 310: Conductive layer stacking structure

[0108] 312:Substrate

[0109] 314:Metal layer

[0110] 316: Thickening layer

[0111] 318: Conductive layer

[0112] 330: Conductive layer stack

[0113] 332:Substrate

[0114] 334:Metal layer

[0115] 336: Conductive layer

[0116] 338: Thickening layer

[0117] 350: Conductive layer stacking structure

[0118] 352:Substrate

[0119] 354: Conductive layer

[0120] 356:Metal layer

[0121] 358: Thickening layer

[0122] 410: Conductive layer stacking structure

[0123] 412: Conductive layer

[0124] 414: Structural layer with double-sided metal film

[0125] 414A:Metal layer

[0126] 414B:Substrate

[0127] 414C:Metal layer

[0128] 416: Thickening layer

[0129] 418: Conductive layer

[0130] 430: Conductive layer stack

[0131] 432: Conductive layer

[0132] 434: Structural layer with double-sided metal film

[0133] 434A:Metal layer

[0134] 434B:Substrate

[0135] 434C:Metal layer

[0136] 436: Conductive layer

[0137] 438: Thickening layer

[0138] 450: Conductive layer stacking structure

[0139] 452:Metal layer

[0140] 454: Structural layer with double-sided conductive film

[0141] 454A: Conductive layer

[0142] 454B:Substrate

[0143] 454C: Conductive layer

[0144] 456:Metal layer

[0145] 458: Thickening layer

[0146] 502:Substrate

[0147] 504:Metal layer

[0148] 506: Photoresist layer

[0149] 508: Thickening layer

[0150] 510: Photoresist layer

[0151] 512: Conductive layer

[0152] 514: Photoresist layer

[0153] 516: Protective layer

[0154] 522:Substrate

[0155] 524:Metal layer

[0156] 526: Photoresist layer

[0157] 528: Conductive layer

[0158] 530: Photoresist layer

[0159] 532: Thickening layer

[0160] 534: Photoresist layer

[0161] 536: Protective layer

[0162] 602:Substrate

[0163] 604: Conductive layer

[0164] 606: Metal layer

[0165] 608: Photoresist layer

[0166] 610: Thickening layer

[0167] 612: Photoresist layer

[0168] 614: Protective layer

[0169] 702:Substrate

[0170] 704:Metal layer

[0171] 706: Photoresist layer

[0172] 708: Conductive layer

[0173] 710: Photoresist layer

[0174] 712: Protective layer

[0175] 714: Thickening layer

[0176] 722:Substrate

[0177] 724: Conductive layer

[0178] 726:Metal layer

[0179] 728: Photoresist layer

[0180] 730: first polymer layer

[0181] 732: Second polymer layer

[0182] AA, BB, CC: Line

[0183] R 1 , R 2 : Radius of curvature

[0184] W 1 , W 2 :length

[0185] θ 1 ,θ 2 :angle DETAILED DESCRIPTION

[0186] The present disclosure provides many different embodiments or examples to implement different features of the present disclosure. Specific examples of components and configurations are described below to simplify the present disclosure. These are of course only examples and are not intended to be limiting. For example, in the subsequent description, a second feature is formed above or on a first feature, which may include embodiments in which the first and second features are in direct contact, and may also include embodiments in which additional features may be formed between the first and second features, so that the first and second features may not be in direct contact.

[0187] Spatially relative terms, such as "below," "below," "lower," "above," "upper," and the like, may be used herein to describe the relationship of one element or feature to another element or feature as depicted in the accompanying drawings. The spatially relative terms are intended to encompass different orientations of the device or apparatus in use or operation in addition to the orientation depicted in the drawings. The device or apparatus may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative terms used herein interpreted accordingly.

[0188] Currently, metal oxides such as indium tin oxide (ITO) are commonly used as materials for conductive layer stacks in display devices to form wiring. However, metal oxide materials such as indium tin oxide are brittle and have poor flexibility, so the conductive layer stacks made from them are easily broken. In addition, in the conductive layer stacks with nanosilver as the conductive layer, since the bending area of ​​the display device still contains other metal wires in addition to the nanosilver wires, the stress value that the metal material itself can withstand is relatively small, and it is easy to deform and cause the resistance value to increase.

[0189] There are two key points in the wiring design of foldable electronic devices: first, because the bends must withstand tens of thousands of folds, the bends need to have a certain structural strength; second, the wiring of foldable electronic devices must have good foldability, that is, a smaller bending radius of curvature.

[0190] Some embodiments of the present disclosure provide a conductive layer stack structure, in which a thickened layer is added on the tensile side of the bend that is subjected to the maximum stress, thereby achieving improved folding characteristics at a smaller radius of curvature.

[0191] In some embodiments, the conductive layer stack can be formed into routing lines of an electronic device and applied to a foldable electronic device, for example, an electronic device with a panel, such as a mobile phone, a tablet, a wearable electronic device (e.g., a smart bracelet, a smart watch, a virtual reality device, etc.), a television, a monitor, a notebook computer, an e-book, a digital photo frame, a navigator, or the like.

[0192] Figure 1A Schematic diagrams of panels according to some embodiments of the present disclosure are shown. Panel 100 is a foldable panel that can be bent along line AA (perpendicular to the direction in which the traces extend) or along line BB (parallel to the direction in which the traces extend). A plurality of traces 110 are provided at the edge of panel 100 for conducting signals. As shown in the figure, the location of the traces 110 of panel 100 has a plurality of locally thickened regions 112, 114, and 116.

[0193] Figure 1B According to some embodiments, along Figure 1ASchematic diagram of a partial cross-section of the routing (conductive layer stack) of line CC in the locally thickened region 114. The conductive layer stack 120 includes a substrate 122, a metal layer 124 above the substrate 122, a thickening layer 126 above the metal layer 124, and a conductive layer 128 above the thickening layer 126. The substrate 122, the metal layer 124, and the conductive layer 128 are layers also present in other regions of the routing 110. In some embodiments, in a local region of the routing 110 (for example, in the conductive layer stack 120), a thickening layer 126 is added between the metal layer 124 and the conductive layer 128. In other embodiments, the length of the thickening layer 126 along the extension direction of the routing 110 is not greater than the length of the conductive layer 128.

[0194] In some embodiments, the material of the substrate 122 may be polyethyleneterephthalate (PET), cycloolefin polymer (COP), polyimide (PI), polycarbonate (PC), colorless polyimide (CPI), polyethylene naphthalate (PEN), or the like. In some embodiments, the material of the metal layer 124 may be gold, palladium, silver, copper, nickel, alloys thereof, or combinations thereof. In some embodiments, the material of the conductive layer 128 may be indium tin oxide (ITO), silver nanowires, metal meshes, conductive polymers (e.g., poly(3,4-ethylenedioxythiophene) / poly(styrenesulfonic acid) (PEDOT / PSS)), carbon nanotubes, graphene, or the like.

[0195] In some embodiments, the material of the thickening layer 126 may be a metal, a non-metal, or a composite conductive material. The metal may be, for example, gold, palladium, silver, copper, nickel, an alloy thereof, or a combination thereof. The non-metal may be, for example, a polymer insulating material (e.g., a protective layer) or a polymer conductive material (e.g., PEDOT / PSS). The composite conductive material may be, for example, nanosilver / carbon black / nanocarbon tubes / graphene doped with metal particles and resin. In some embodiments, the material of the thickening layer has good connection and adhesion with the material of the layer below it to form a good conductor.

[0196] In some embodiments, forming the thickening layer may be achieved by a patterning process, such as lithography, inkjet printing (IJP), spraying, screen printing, flexo printing, or the like.

[0197] Please see Figure 1C In other embodiments, along Figure 1A The routing portion (conductive layer stacking structure) of line CC in the locally thickened region 114 is Figure 1C The conductive layer stack 130 shown in FIG. The conductive layer stack 130 includes a substrate 132, a conductive layer 134 above the substrate 132, a metal layer 136 above the conductive layer 134, and a thickening layer 138 above the metal layer 136. The substrate 132, the conductive layer 134, and the metal layer 136 are layers also present in other regions of the trace 110. In some embodiments, in a local region of the trace 110 (for example, in the conductive layer stack 130), a thickening layer 138 is added above the conductive layer 134 and the metal layer 136. In other embodiments, the length of the thickening layer 138 along the extension direction of the trace 110 is not greater than the length of the conductive layer 134.

[0198] The materials of each layer of the conductive layer stack 130 can be Figure 1B The materials of the various layers of the conductive layer stack structure 120 are the same and can be formed by the same process as described above.

[0199] Please see Figure 1D In yet other embodiments, along Figure 1A The routing portion (conductive layer stacking structure) of line CC in the locally thickened region 114 is Figure 1D The conductive layer stack 140 shown. The conductive layer stack 140 includes a substrate 142, a metal layer 144 above the substrate 142, a conductive layer 146 above the metal layer 144, and a thickening layer 148 above the conductive layer 146. The substrate 142, the metal layer 144, and the conductive layer 146 are layers also present in other regions of the trace 110. In some embodiments, in a local region of the trace 110 (for example, in the conductive layer stack 140), a thickening layer 148 is added above the metal layer 144 and the conductive layer 146. In other embodiments, the length of the thickening layer 138 along the extension direction of the trace 110 is not greater than the length of the conductive layer 134.

[0200] The materials of each layer of the conductive layer stack 140 can be Figure 1B The materials of the various layers of the conductive layer stack structure 120 are the same and can be formed by the same process as described above.

[0201] Please see Figure 1E , which is Figure 1A The width of the trace 110 is W. 1 , the spacing between the traces is P 1, the dotted line is the bending line when the device is bent. In some embodiments, the region with the thickened layer is in the portion of the wiring in the non-display area. In the first direction (the direction in which the wiring extends, i.e., the y direction), the length of the region with the thickened layer is L 1 .

[0202] In some embodiments, in the second direction (a direction perpendicular to the first direction, i.e., the x direction), the width of the thickening layer may be the width of a single trace 110, i.e., individual thickening layers are located in different traces. 1 In other embodiments, when the thickening layer is formed of a non-metallic material, such as a polymer material, a whole thickening layer can be formed which is located within the range of the plurality of traces 110, that is, a single thickening layer covers the conductive layer of the plurality of traces 110. That is, when there are N traces, the width dimension Wt of the thickening layer is equal to or slightly greater than N x W 1 +(N-1)x P 1 Alternatively, the width dimension W of the thickened layer t is approximately equal to N x(W 1 +P 1 ). Therefore, the width dimension range of the thickened layer in the second direction may be between about W 1 Peace Treaty 1 +P 1 )x N.

[0203] Figure 2A and Figure 2B A schematic diagram of the bending area of ​​the conductive layer stack is shown in a bent state. The length of the area covered by the thickened layer is related to the curvature radius and the bending angle during bending. Figure 2A In the illustrated conductive layer stack 20, the conductive layer stack extends along a first direction (x direction), and the thickening layer 26 is located above the substrate 22 and the wiring material layer (metal or non-metal) 24. Figure 2A The radius of curvature is R 1 , the bending angle is θ 1 , the length of the thickened layer 26 is W 1 .exist Figure 2B In the conductive layer stack structure 30, the radius of curvature is R 2 , the bending angle is θ 2 The thickening layer 36 is located above the substrate 32 and the wiring material layer 34 and has a length of W 2 .

[0204] In some embodiments, the length of the thickened layer along the first direction depends on the radius of curvature and the bending angle of the foldable electronic device. In some embodiments, the radius of curvature of the conductive layer stack is 1 mm, the bending angle is 180 degrees, and the length of the thickened layer along the first direction is at least 3 mm.

[0205] In some embodiments, the conductive layer stack extends along the first direction, and the length of the thickened layer in the bending zone in the first direction depends on the curvature radius and the bending angle of the electronic component device when bending. The length of the thickened layer needs to be at least greater than the arc length range corresponding to the curvature radius of 180°.

[0206] In some embodiments, the length of the thickening layer is greater than 15 millimeters (mm), and the angle between the bending axis and the two ends of the thickening layer is 180° to 360° (varies with the length of the thickening layer); compared to a conductive layer stack structure without a thickening layer, the conductive layer stack structure in the embodiment of the present disclosure can increase the stress strain during bending by 0.1 to 10%, and the curvature radius of the conductive layer stack structure can be reduced by 0.5 to 3 millimeters.

[0207] In some embodiments, the conductive layer stack extends along a first direction, the length of the thickened layer in the first direction is greater than 9 mm, and when bent with a curvature radius of about 3 mm, the angle between the center point of the curvature radius and the two ends of the thickened layer is about 180°.

[0208] In other embodiments, the conductive layer stack extends along a first direction, and the length of the thickened layer in the first direction is greater than 15 mm. When bent with a curvature radius of about 5 mm, the angle between the center point of the curvature radius and the two ends of the thickened layer is about 180°.

[0209] In some embodiments, the conductive layer extends along the first direction, and the ratio of the length of the thickened layer in the first direction to the length of the conductive layer extending along the first direction is 0.001-1, for example, 0.001, 0.005, 0.01, 0.02, 0.05, 0.08, 0.1, 0.2, 0.5, or 0.8.

[0210] In some embodiments, the conductive stack of the present disclosure may be applied to routing of a foldable electronic device. The foldable electronic device includes a first portion, a re-foldable region connected to the first portion, and a second portion connected to the re-foldable region. The routing includes a thickened layer in the re-foldable region, which is located on the side that bears the tensile stress when the foldable electronic device is folded, so as to reduce the risk of routing breakage. The angle between the first portion and the second portion when the foldable electronic device is not folded may be 150 degrees to 180 degrees or 180 degrees to 210 degrees, and the angle between the first portion and the second portion when the foldable electronic device is folded may be 0 degrees to 30 degrees or 330 degrees to 360 degrees.

[0211] When the conductive layer stack is formed into a conductive trace and applied to a foldable electronic device, the resistance change (increase) of the conductive trace should be as small as possible under the action of multiple bending stresses. Once the conductive trace is cracked or broken, the resistance of the conductive trace increases or even fails, which will cause the performance of the foldable electronic device to deteriorate or even malfunction. The definition of fracture described in this article is that the resistance of the conductive trace increases by more than 10%.

[0212] The following comparative examples (see FIG. 3A to FIG. 3B ) and experimental examples (see FIG. 4A to FIG. 4C ) illustrates the test results of the bending test of the conductive layer stack structure of the embodiment of the present case.

[0213] The bending test was conducted using a bending machine of model DMLHP-CS produced by Yuasa Battery to test the conductive layer stacks of various embodiments and comparative examples. The test conditions were a curvature radius of 3 mm, a bending frequency of 30 times per minute, and a maximum folding force of 4 Nm. The bending times and resistance change percentages of different conductive layer stacks were then recorded.

[0214] Figure 3A Schematic diagrams showing the conductive layer stack structure 40 in a bent state according to some comparative examples; Figure 3B A schematic diagram of the conductive layer stack 40 in a non-bent state is shown. The conductive layer stack 40 includes a substrate 42 and a metal layer 44 on the substrate 42. In addition, the line length of the conductive layer stack 40 is 100 μm. In the conductive layer stack 40, the substrate 42 is made of PET, with a thickness of 50 μm and a Young's modulus of 2 to 3 GP. The metal layer 44 is made of a copper layer, with a thickness of 0.3 μm and a Young's modulus of 140 GPa. Figure 3B The dotted line shown in is the position of the neutral axis during bending.

[0215] Table 1 below shows the results of bending tests of conductive layer stacks of different comparative examples at a curvature radius of 3 mm and an angle of 180°. The metal layers (copper layers) in the comparative examples are formed by sputtering or different electroplating processes (i.e., chemical plating (I), (II), and (III)).

[0216] Table 1

[0217]

[0218]

[0219] As shown in Table 1, after folding 20,000 times with a curvature radius of 3 mm, the resistance of the conductive layer stacks of the above comparative examples increased significantly. The resistance of the conductive stacks formed by the electroplating (I), electroplating (II), and electroplating (III) processes changed by more than 10%.

[0220] Figure 4A Schematic diagrams of a conductive layer stack 50 in a non-bent state according to some experimental examples are shown. The conductive layer stack 50 includes a substrate 52, a conductive layer 54 on the substrate 52, a metal layer 56 on the conductive layer 54, and a thickening layer 58 on the metal layer 56. The material of the thickening layer 58 is copper. Figure 4A The dotted line shown in is the position of the neutral axis during bending.

[0221] Figure 4B Schematic diagram of a conductive layer stack structure 60 in a non-bending state according to some experimental examples is shown. The conductive layer stack structure 60 includes a substrate 62, a conductive layer 64 above the substrate 62, a metal layer 66 above the conductive layer 64, and a thickening layer 68 above the metal layer 66. The substrate 62 is formed of PET with a thickness of 50 microns. The conductive layer 64 includes nano silver material with a thickness of 0.2-0.5μm. The material of the metal layer 66 is copper with a thickness of 0.2-0.5μm. The thickening layer 68 is a polymer layer, the material of which is acrylic with a thickness of 5 to 10μm. Figure 4B The dotted line shown in is the position of the neutral axis during bending.

[0222] The following table 2 shows the different Figure 4B The conductive layer stack of the embodiment shown in the figure is subjected to a bending test with a curvature radius of 3 mm and an angle of 180°, wherein the control group is a conductive stack without polymer coating (without a thickening layer).

[0223] Table 2

[0224]

[0225]

[0226] As shown in Table 2, after 40,000 folds, the resistance of the conductive layer stacks of the above embodiments did not change significantly; on the contrary, the wiring resistance of the conductive layer stacks without polymer coating increased significantly, indicating that the line was broken. Therefore, the conductive layer stacks of the embodiments have better bending resistance and are significantly better than the conductive layer stacks of the control group without polymer coating.

[0227] Figure 4CA schematic diagram of a conductive layer stack 70 in a non-bending state according to some experimental examples is depicted. The conductive layer stack 70 includes a substrate 72, a conductive layer 74 above the substrate 72, a metal layer 76 above the conductive layer 74, a first polymer layer 78 above the metal layer 76, and a second polymer layer 80 above the first polymer layer 78. That is, in the conductive layer stack 70, the thickening layer is a multilayer formed of a heterogeneous polymer, including a first polymer layer 78 and a second polymer layer 80. In the conductive layer stack 70, the substrate 72 is formed of PET with a thickness of 50 microns. The conductive layer 74 includes nanosilver material with a thickness of less than 100 nm. The material of the metal layer 76 is copper with a thickness of 0.2 to 0.5 μm. The material of the first polymer layer 78 is optical adhesive (OCA) with a thickness of 50 microns. The material of the second polymer layer 80 is PET with a thickness of 50 microns. Figure 4C The dotted line shown in is the position of the neutral axis during bending.

[0228] Table 3 below shows the results of bending tests of conductive layer stacks of different embodiments at a curvature radius of 3 mm and an angle of 180°. The control group is a conductive stack without polymer coating (without a thickening layer). In Table 3, the conductive layer stack containing an OCA layer / PET layer is equivalent to the structure of the embodiment shown in FIG. 4C.

[0229] Table 3

[0230]

[0231]

[0232] As shown in Table 3, after 40,000 folds, the resistance of the conductive layer stack structure of the embodiment having the first polymer layer and the second polymer layer did not change significantly; and after 60,000, 165,000, and 200,000 folds, the resistance of the conductive layer stack structure did not change significantly. That is, after multiple folds, the conductive layer stack structure did not break. Therefore, the conductive layer stack structures of these embodiments have better bending resistance, which is significantly better than the conductive layer stack structure of the control group without polymer coating.

[0233] FIG. 5A to FIG. 5D A schematic diagram of a conductive layer stack structure according to some embodiments of the present disclosure is shown.

[0234] Figure 5A A conductive layer stack 210 is shown, which includes a substrate 212, a wiring material layer 214 on the substrate 212, and a thickening layer 216 on the wiring material layer 214. The wiring material layer 214 may be made of metal, non-metal, or a combination thereof. The thickening layer 216 may be made of metal, non-metal, or a composite conductive material.

[0235] In some embodiments, when the material of the thickening layer 216 is metal, the ratio of the thickness of the thickening layer 216 to the thickness of the routing material layer 214 is 0.05-5, for example, 0.05-0.5, 0.1-1, 0.5-2, or 2-5.

[0236] In some embodiments, when the material of the thickening layer 216 is non-metal or composite conductive material, the ratio of the thickness of the thickening layer 216 to the thickness of the routing material layer 214 is 0.1-50, for example, 0.1-10, 10-20, or 20-50.

[0237] In some embodiments, the thickness (unit: μm) of the substrate 212 of the conductive layer stack 210 multiplied by the Young's modulus (unit: Gpa) is approximately 100 to 300, the thickness of the routing material layer 214 multiplied by the Young's modulus is approximately 20 to 70, the material of the thickening layer 216 is metal, and the thickness of the thickening layer 216 multiplied by the Young's modulus is approximately 5 to 30.

[0238] In some embodiments, the thickness of the substrate 212 of the conductive layer stack 210 multiplied by the Young's modulus is approximately 100 to 300, the thickness of the routing material layer 214 multiplied by the Young's modulus is approximately 20 to 70, the material of the thickening layer 216 is a non-metallic or composite conductive material, and the thickness of the thickening layer 216 multiplied by the Young's modulus is approximately 2 to 60.

[0239] Figure 5B The conductive layer stack 220 is shown, which includes a substrate 222, a wiring material layer 224 above the substrate 222, a first polymer layer 226 above the wiring material layer 224, and a second polymer layer 228 above the first polymer layer 226. In the conductive layer stack 220, the materials of the substrate 222 and the wiring material layer 224 are similar to Figure 5A The substrate 212 and the wiring material layer 214 of the conductive layer stack 210 are shown. In the conductive layer stack 220, the thickening layer is a multilayer formed of a heterogeneous polymer, including a first polymer layer 226 and a second polymer layer 228. The first polymer layer 226 and the second polymer layer 228 are different polymer materials. In some embodiments, the ratio of the Young's modulus of the first polymer layer 226 to the second polymer layer 228 is about 10 3 ~10 6 For example, the first polymer layer 226 is formed of OCA, and the second polymer layer 228 is formed of PET. In the conductive layer stack 220, the ratio of the thickness of the first polymer layer 226 to the thickness of the wiring material layer 224 is about 30 to 100, the ratio of the thickness of the second polymer layer 228 to the thickness of the wiring material layer 214 is about 30 to 100, and the ratio of the thickness of the first polymer layer to the thickness of the second polymer layer is about 0.5 to 2.

[0240] In some embodiments, the thickness of the substrate 222 of the conductive layer stack 220 multiplied by the Young's modulus is approximately 100-300, the thickness of the routing material layer 224 multiplied by the Young's modulus is approximately 20-70, the thickness of the first polymer layer 226 multiplied by the Young's modulus is approximately 2-60, and the thickness of the second polymer layer 228 multiplied by the Young's modulus is approximately 100-300.

[0241] Figure 5C The conductive layer stack 230 is shown, which includes a substrate 232, a catalyst layer 234 on the substrate 232, a conductive layer 236 on the catalyst layer 234, and a thickening layer 238 on the conductive layer 236. In the conductive layer stack 230, the substrate 232 and the thickening layer 238 are similar to Figure 5A The substrate 212 and the thickening layer 216 in the conductive layer stack 210 are shown. In some embodiments, the material of the catalyst layer 234 may be any one of palladium, rhodium, platinum, iridium, osmium, gold, nickel, iron, etc. In the conductive layer stack 230, the material of the conductive layer 236 is metal, for example, a copper layer may be formed on the catalyst layer 234 through a chemical plating process, and the ratio of the thickness of the conductive layer 236 to the thickness of the catalyst layer 234 is about 0.5-5, or about 2-10.

[0242] Figure 5D A conductive layer stack 240 is shown, which includes a substrate 242, a catalyst layer 244 on the substrate 232, a conductive layer 246 on the catalyst layer 244, a first polymer layer 248 on the conductive layer 246, and a second polymer layer 250 on the first polymer layer 248. In the conductive layer stack 240, the substrate 242, the first polymer layer 248, and the second polymer layer 250 are similar to Figure 5B The substrate 222, the first polymer layer 226, and the second polymer layer 228 in the conductive layer stack 220 are shown. In some embodiments, the material of the catalyst layer 244 may be any one of palladium, rhodium, platinum, iridium, osmium, gold, nickel, iron, etc. In the conductive layer stack 240, the material of the conductive layer 246 is metal, for example, a copper layer may be formed on the catalyst layer 244 through a chemical plating process, and the ratio of the thickness of the conductive layer 246 to the thickness of the catalyst layer 244 is about 0.5-5, or about 2-10.

[0243] 6A to 6F A schematic diagram illustrating a conductive layer stack structure applied to a single-sided foldable electronic device according to some embodiments is shown.

[0244] Fig. 6A is a schematic diagram of the conductive layer stack structure 310 being folded in a U shape, Figure 6B FIG. 3 is a schematic diagram of the conductive layer stack structure 310 when it is unfolded.

[0245] The conductive layer stack structure 310 includes a substrate 312, a metal layer 314 on the substrate 312, and a conductive layer 318 on the metal layer, and a thickening layer 316 is formed between the metal layer 314 and the conductive layer 318 at the bend. In some embodiments, at the bend, the metal layer 314 is locally thickened to form a thickening layer 316 made of metal or a composite conductive composite, and then the conductive layer 318 containing nano silver wires is coated.

[0246] Figure 6C is a schematic diagram of the conductive layer stack structure 330 being folded in a U shape, Fig.6D FIG. 3 is a schematic diagram of the conductive layer stack structure 330 when it is unfolded.

[0247] The conductive layer stack structure 330 includes a substrate 332, a metal layer 334 on the substrate 332, and a conductive layer 336 on the metal layer, and a thickening layer 338 is formed on the conductive layer 336 at the bend. In some embodiments, at the bend, the conductive layer 336 containing nano silver wires is first coated, and then the thickening layer 338 made of metal, non-metal, or composite conductive material is locally formed.

[0248] Fig. 6E is a schematic diagram of the conductive layer stack structure 350 being folded in a U shape, Fig. 6F FIG. 3 is a schematic diagram of the conductive layer stack structure 350 when it is unfolded.

[0249] The conductive layer stack structure 350 includes a substrate 352, a conductive layer 354 on the substrate 352, and a metal layer 356 on the conductive layer 354, and a thickening layer 358 is formed on the metal layer 356 at the bend. In some embodiments, the thickening layer 358 made of metal, non-metal, or composite conductive material is locally formed on the metal layer 356 at the bend.

[0250] 7A to 7F A schematic diagram illustrating a conductive layer stack structure applied to a double-sided foldable electronic device according to some embodiments is shown.

[0251] Fig. 7A is a schematic diagram of the conductive layer stack structure 410 being folded in an S shape, Figure 7B FIG. 4 is a schematic diagram of the conductive layer stack structure 410 when it is unfolded.

[0252] The conductive layer stack 410 includes a structure layer 414 having double-sided metal films, conductive layers 412 and 418 on both sides of the structure layer 414 having double-sided metal films, and a thickening layer 416 located at a bend.

[0253] The structural layer 414 having a double-sided metal film includes a substrate 414B, and metal layers 414A and 414C are formed on both sides of the substrate 414B. At the bend, the thickened layer 416 is located between the metal layer 414A and the conductive layer 412, and between the metal layer 414C and the conductive layer 418. In some embodiments, at the bend, the metal layer 314 is locally thickened to form a thickened layer 416 made of a metal or composite conductive material, and then the conductive layers 412 and 418 containing nano silver wires are coated.

[0254] Figure 7C is a schematic diagram of the conductive layer stack structure 430 being folded in an S shape, Fig.7D FIG. 4 is a schematic diagram of the conductive layer stack structure 430 when it is unfolded.

[0255] The conductive layer stack 430 includes a structure layer 434 having double-sided metal films, conductive layers 432 and 436 on both sides of the structure layer 434 having double-sided metal films, and a thickening layer 438 located at a bend.

[0256] The structural layer 434 having a double-sided metal film includes a substrate 434B, and metal layers 434A and 434C are formed on both sides of the substrate 434B. At the bend, a thickening layer 438 is located on the conductive layers 432 and 436. In some embodiments, after the conductive layers 432 and 436 containing nanosilver wires are coated first, a thickening layer 438 made of metal, non-metal, or composite conductive material is formed at the bend.

[0257] Fig. 7E is a schematic diagram of the conductive layer stack structure 450 being folded in an S shape, Figure 7F FIG. 4 is a schematic diagram of the conductive layer stack structure 450 when it is unfolded.

[0258] The conductive layer stack 450 includes a structure layer 454 having a double-sided conductive film (eg, a transparent conductive layer), metal layers 452 and 456 on both sides of the structure layer 454 having a double-sided conductive film, and a thickening layer 458 located at a bend.

[0259] The double-sided conductive film structure layer 454 includes a substrate 454B, and conductive layers 454A and 454C are formed on both sides of the substrate 454B. In some embodiments, a thickened layer 458 made of metal, nonmetal, or composite conductive material is locally formed on the metal layers 452 and 456 at the bend.

[0260] The following provides a method for manufacturing a foldable device having a conductive layer stack structure with a thickened layer.

[0261] FIG. 8A to FIG. 8IA process according to some embodiments is shown to form a foldable electronic device whose layers sequentially include a single-side metal film (SMF), a selective growth metal (SGM) and a conductive layer, wherein the thickened layer is a metal material.

[0262] like Fig. 8A As shown, a substrate 502 having a metal layer 504 is provided. A metal material such as copper may be formed on the substrate 502 by sputtering or electroplating.

[0263] like Figure 8B As shown, a photoresist layer 506 is then formed on the metal layer 504 , and exposure and development are performed to pattern the photoresist layer 506 .

[0264] like Figure 8C As shown, an etching process is then performed to etch the portion of the metal layer 504 not covered by the patterned photoresist layer 506 to form a patterned metal layer 504. The photoresist layer 506 is then stripped.

[0265] like Fig.8D As shown, a photoresist layer 510 is formed between the spaces of the patterned metal layer 504, and is exposed and developed. Then, a thickening layer 508 is selectively grown on the metal layer 504. In some embodiments, a copper material is formed on the metal layer 504 by sputtering or electroplating.

[0266] like Fig. 8E As shown, the photoresist layer 510 is removed, and a conductive layer 512 is disposed on the substrate 502, the metal layer 504, and the thickened layer 508. In some embodiments, a conductive material containing nanosilver wires or ITO can be formed into the conductive layer 512 by coating.

[0267] like Fig.8F As shown, a photoresist layer 514 is provided, and exposed and developed to form a patterned photoresist layer 514 .

[0268] like Figure 8G As shown, etching is then performed to etch the conductive layer 512, the thickened layer 508, and the metal layer 504 that are not covered by the patterned photoresist layer. Thus, a plurality of separated traces are formed.

[0269] like Figure 8H As shown, the photoresist layer 514 is stripped off.

[0270] like Figure 8I As shown, a protective layer (over coating) 516 is disposed over the substrate 502, the metal layer 504, the thickening layer 508, and the conductive layer 512. Figure 8IIn the structure shown, the thickened layer 508 is located between the metal layer 504 and the conductive layer 512 in the trace.

[0271] FIG. 9A to FIG. 9J A process according to some embodiments is shown to form a foldable electronic device, wherein the layers sequentially include a single-sided metal film, a conductive layer, and a selectively grown metal, wherein the thickened layer is a metal material.

[0272] like Fig.9A As shown, a substrate 522 having a metal layer 524 is provided. A metal material such as copper may be formed on the substrate 522 by sputtering or electroplating.

[0273] like Fig. 9B As shown, a photoresist layer 526 is formed on the metal layer 524 and is exposed and developed to form a patterned photoresist layer 526 .

[0274] like Fig. 9C As shown, an etching process is then performed to etch the portion of the metal layer 524 not covered by the patterned photoresist layer 526 to form a patterned metal layer. The photoresist layer 526 is then stripped.

[0275] like Fig.9D As shown, a conductive layer 528 is disposed on the substrate 522 and the metal layer 524. The conductive layer 528 may be formed of a conductive material containing nano silver wires or ITO by coating.

[0276] like Fig.9E As shown, a photoresist layer 530 is formed, and a patterned photoresist layer 530 is formed through exposure and development.

[0277] like Fig.9F As shown, a thickening layer 532 is disposed on the conductive layer in the area not covered by the patterned photoresist layer 530. In some embodiments, the conductive layer 528 may be selectively grown, such as by sputtering or electroplating a copper material.

[0278] like Figure 9G As shown, the photoresist layer 530 is stripped.

[0279] like Figure 9H As shown, a photoresist layer 534 is formed, and a patterned photoresist layer 534 is formed through exposure and development.

[0280] like Fig.9I As shown, etching is then performed to remove the thickened layer 532, the conductive layer 528, and the metal layer 524 that are not covered by the patterned photoresist layer 534. Thus, a plurality of separated traces are formed. The photoresist layer 534 is then stripped.

[0281] like Figure 9JAs shown, a protective layer 536 is disposed over the substrate 522, the metal layer 524, the conductive layer 528, and the thickening layer 532. Figure 9J In the structure shown, the thickened layer 532 is located above both the metal layer 524 and the conductive layer 528 in the trace.

[0282] FIG. 10A to FIG. 10G A process according to some embodiments is shown to form a foldable electronic device, wherein the layers sequentially include a conductive layer, a single-sided metal film, and a selectively grown metal, wherein the thickened layer is a metal material.

[0283] like Fig. 10A As shown, a substrate 602 including a conductive layer 604 (transparent conductive film) is first provided, and then a metal layer 606 is disposed on the conductive layer 604. In some embodiments, a copper material may be formed on the conductive layer 604 by sputtering or electroplating.

[0284] like Fig. 10B As shown, a photoresist layer 608 is formed, and a patterned photoresist layer 608 is formed through exposure and development.

[0285] like Fig. 10C As shown, a thickening layer 610 is disposed on the portion of the metal layer 606 not covered by the photoresist layer 608. In some embodiments, a copper material may be disposed on the metal layer 606 by selectively growing a metal layer, such as sputtering or electroplating.

[0286] like Fig. 10D As shown, the photoresist layer 608 is stripped.

[0287] like Fig. 10E As shown, a photoresist layer 612 is disposed on the thickening layer 610 and the metal layer 606 , and is exposed and developed to form a patterned photoresist layer 612 .

[0288] like Fig.10F As shown, etching is then performed to remove the thickened layer 610, the metal layer, and the conductive layer 604 that are not covered by the patterned photoresist layer 612. Thus, a plurality of separated traces are formed.

[0289] like Figure 10G As shown, the metal layer 606 in the middle area (eg, the display area of ​​the electronic device to be formed later) is removed. Then, a protective layer 614 is disposed on the thickening layer 610, the metal layer 606, and the conductive layer 604. Figure 10G In the structure shown, a thickened layer 610 is located above both the conductive layer 604 and the metal layer 606 in the trace.

[0290] FIG. 11A to FIG. 11HA process according to some embodiments is shown to form a foldable electronic device, wherein the layers sequentially include a metal layer, a conductive layer, and a thickening layer, wherein the thickening layer is a non-metallic material, such as a polymer material.

[0291] like Fig.11A As shown, a substrate 702 having a metal layer 704 is provided. A metal material such as copper may be formed on the substrate 702 by sputtering or electroplating.

[0292] like Fig. 11B As shown, a photoresist layer 706 is formed on the metal layer 704 , and is exposed and developed to form a patterned photoresist layer 706 .

[0293] like Fig. 11C As shown, the metal layer 704 not covered by the patterned photoresist layer 706 is etched. The photoresist layer 706 is then stripped.

[0294] like Fig.11D As shown, a conductive layer 708 is disposed above the substrate 702 and the metal layer 704. The conductive layer 708 may be formed of a conductive material containing nano silver wires or ITO by coating.

[0295] like Fig.11E As shown, a photoresist layer 710 is formed on the conductive layer 708 , and a patterned photoresist layer 710 is formed through exposure and development.

[0296] like Fig.11F As shown, etching is then performed to remove the portions of the conductive layer 708 and the metal layer 704 that are not covered by the patterned photoresist layer 710 to form a plurality of separated traces.

[0297] like Fig.11G As shown, the photoresist layer 710 is then stripped. In the subsequent process, a protection layer 712 is formed on each wiring. The protection layer 712 can be formed of a polymer material.

[0298] like Fig.11H As shown, a thickening layer 714 is then formed on the protective layer 712. The thickening layer 714 may be formed of another polymer material different from the protective layer 712.

[0299] FIG. 12A to FIG. 12H A process according to some embodiments is shown to form a foldable electronic device, wherein the layers sequentially include a conductive layer, a metal layer, and a thickening layer, wherein the thickening layer is a non-metallic material, such as a polymer material.

[0300] like Fig. 12AAs shown, a substrate 722 including a conductive layer 724 is first provided. The conductive layer 724 may include, for example, nanosilver wires. In some embodiments, a protective layer (not shown) is provided on the conductive layer 724. A metal layer 726 is then provided on the conductive layer 724. In some embodiments, a copper material may be formed on the conductive layer 724 by sputtering or electroplating.

[0301] like Fig. 12B As shown, a photoresist layer 728 is formed on the metal layer 726 , and a patterned photoresist layer 728 is formed by exposure and development.

[0302] like Fig. 12C As shown, the metal layer 726 and the conductive layer 724 that are not covered by the patterned photoresist layer 728 are etched, thereby forming a plurality of isolated traces.

[0303] like Fig.12D As shown, the photoresist layer 728 in the middle area is peeled off.

[0304] like Fig.12E As shown, the metal layer 726 in the middle region is removed.

[0305] like Fig.12F As shown, the photoresist layer 728 is stripped.

[0306] like Figure 12G As shown, a first polymer layer 730 is formed over the various traces and over the conductive layer 724 .

[0307] like Fig.12H As shown, a second polymer layer 732 is formed over the substrate 722, the conductive layer 724, and the metal layer 726 at the periphery (i.e., the non-display area) of the device. Fig.12H In the structure shown, the second polymer layer 732 or the combination of the first polymer layer 730 and the second polymer layer 732 is equivalent to the thickening layer of the trace.

[0308] The conductive layer stacking structure disclosed in the present invention enables the foldable electronic device to have a smaller bending radius of curvature, enhances foldability, and can still have good reliability in routing after multiple bends, thereby improving product quality and increasing the life of the device.

[0309] Several embodiments are summarized above so that those skilled in the art can better understand the various aspects of the present disclosure. Those skilled in the art will understand that they can use the present disclosure as a basis for designing or modifying other processes and structures to achieve the same purposes and / or achieve the same advantages as the embodiments or examples described herein. Those skilled in the art will also understand that these equivalent constructions do not depart from the spirit and scope of the present disclosure, and they may make various changes, substitutions, and modifications without departing from the spirit and scope of the present disclosure.

Claims

1. A foldable electronic device, It is characterized in that Include: a display area; and A non-display area is located outside the display area, wherein the non-display area has a plurality of wirings extending along a first direction, and each of the plurality of wirings includes: a substrate, and a conductive layer located above the substrate; The non-display area has a local thickened area, which includes a bending point of the foldable electronic device. Each of the multiple wirings in the local thickened area further includes a thickened layer, which is above or below the conductive layer and located on a stress-stretching side when the foldable electronic device is bent. The thickened layer is formed of a metal material, and the ratio of the thickness of the thickened layer to the conductive layer is 0.05 to 5.

2. The foldable electronic device according to claim 1, It is characterized in that The local thickened region has a width extending along a second direction perpendicular to the first direction, and a width of one of the traces is W. 1 , the spacing between the traces is P 1 The number of the routing lines is N, and the width of the local thickening area ranges from W 1 To (W 1 +P 1 )xN.

3. The foldable electronic device according to claim 1, It is characterized in that The length of the thickened layer along the first direction is greater than 3 mm.

4. The foldable electronic device according to claim 1, It is characterized in that The value of the thickness of the substrate multiplied by the Young's modulus of the substrate is 100-300, the value of the thickness of the conductive layer multiplied by the Young's modulus of the conductive layer is 20-70, and the value of the thickness of the thickening layer multiplied by the Young's modulus of the thickening layer is 5-30.

5. A foldable electronic device, It is characterized in that Include: a display area; and A non-display area is located outside the display area, wherein the non-display area has a plurality of wirings extending along a first direction, and each of the plurality of wirings includes: a substrate, and a conductive layer located above the substrate; The non-display area has a local thickened region, which includes a bend of the foldable electronic device, and each of the plurality of traces in the local thickened region further includes a thickened layer, which is above or below the conductive layer and located on a stress-stretching side when the foldable electronic device is bent, wherein the thickened layer includes: a first polymer layer; and a second polymer layer, above the first polymer layer, wherein the material of the first polymer layer is different from the material of the second polymer layer, and the ratio of the Young's modulus of the first polymer layer to the Young's modulus of the second polymer layer is 10 3 ~10 6 .

6. The foldable electronic device according to claim 5, It is characterized in that The ratio of the thickness of the first polymer to the thickness of the conductive layer is 30-100, the ratio of the thickness of the second polymer to the thickness of the conductive layer is 30-100, and the ratio of the thickness of the first polymer to the thickness of the second polymer is 0.5-2.

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