CN212061907U - Conductive layer structure and foldable electronic device - Google Patents

Abstract

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

Description

Conductive layer structure and foldable electronic device

technical field

The present disclosure relates to conductive stack structures, particularly conductive stack structures used in traces of foldable electronic devices.

Background technique

Electronic components are constantly developing towards miniaturization and high-speed development. Among them, flexible electronic technology, which can maintain high performance and make electronic components flexible, is the most eye-catching new technology in the next generation, including flexible panels, displays, batteries, Wearable electronic devices, etc.

However, in the foldable electronic device, the wires at the bend may be prone to breakage after being bent for many times, thereby affecting the transmission of signals and the performance of the foldable electronic device.

Utility model content

In view of the above problems, an object of the present disclosure is to provide a conductive laminate structure with a thickened layer to improve the bending resistance of a foldable electronic device.

Some embodiments of the present disclosure provide a conductive layered structure including a conductive layer and a thickened layer. The conductive layer extends along the first direction. The thickened layer is located above or below the conductive layer, and the conductive layer structure can withstand more than 40,000 folding times without breaking when the conductive layer is bent at 180° with a radius of curvature R=3 mm and perpendicular or parallel to the extending direction of the first direction.

In some embodiments, the length of the thickened layer in the first direction is greater than 9 millimeters and does not exceed the length of the conductive layer extending in the first direction.

In some embodiments, the length of the thickened layer in the first direction is greater than 15 millimeters and does not exceed the length of the conductive layer extending in the first direction.

In some embodiments, the included angle between the bending axis of the conductive layer structure and the two ends of the thickened layer is 180°˜360°.

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

In some embodiments, the thickened layer is on the stress-stretch side of the conductive laminate when it is bent.

In some embodiments, a foldable electronic device is proposed, which includes the conductive laminate structures described in the above and below embodiments or examples.

Some embodiments of the present disclosure provide a foldable electronic device including 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 wirings extending along the first direction, and each wiring in the plurality of wirings includes a substrate and a conductive layer located above the substrate. Wherein the non-display area has a local thickening area, which includes the bend of the foldable electronic device, and each of the multiple wires in the local thickening area further includes a thickening layer, which is above the conductive layer or below, and is located on the stress stretching side when the foldable electronic device is bent.

In some embodiments, in the foldable electronic device, the width of the locally thickened region extends along a second direction perpendicular to the first direction, and one of the traces has a width W ₁ , and the traces have a width of W 1 . The spacing between them is P ₁ , the number of these traces is N, and the width of the locally thickened region ranges from W ₁ to (W ₁ +P ₁ )×N.

In some embodiments, in the foldable electronic device, the length of the thickened layer in the first direction is greater than 3 millimeters.

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

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

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

In some embodiments, in the 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 about 100-300, and the thickness of the conductive layer is about 100-300. The value of the thickness 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 of the thickened layer is about 2 to 60.

In some embodiments, in a foldable electronic device, the thickening layer comprises: a first polymer layer and a second polymer layer. The second polymer layer is above the first polymer layer, wherein the material of the first polymer layer is different from the material of the second polymer layer.

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 to 10 ⁶ .

In some embodiments, in the foldable electronic device, the ratio of the thickness of the first polymer to the thickness of the conductive layer is about 30-100, and the ratio of the thickness of the second polymer to the thickness of the conductive layer is about 30-100 , and the ratio of the thickness of the first polymer to the thickness of the second polymer is about 0.5-2.

Description of drawings

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

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

1B-1D are partial cross-sectional views of traces according to some embodiments of the present disclosure;

FIG. 1E is a partial enlarged view of region 114 of the panel in FIG. 1A ;

2A and 2B are schematic diagrams of the conductive layer structure in a bent state;

3A and 3B are schematic diagrams of a bent state and a non-bent state of a conductive laminate structure of a comparative example;

4A to 4C are respectively conductive layered structures according to some experimental examples;

5A-5D are schematic diagrams of the configuration of a conductive stack structure according to some embodiments;

6A and 6B are schematic diagrams of a conductive layer structure in a bent state and an unfolded state according to some embodiments;

6C and 6D are schematic diagrams of a conductive layer structure in a bent state and an unfolded state according to some embodiments;

6E and 6F are schematic diagrams of a conductive layer structure in a bent state and an unfolded state according to some embodiments;

7A and 7B are schematic diagrams of a conductive layer structure in a bent state and an unfolded state according to some embodiments;

7C and 7D are schematic diagrams of a conductive layer structure in a bent state and an unfolded state according to some embodiments;

7E and 7F are schematic diagrams of a conductive layer structure in a bent state and an unfolded state according to some embodiments;

8A-8I are cross-sectional views of a foldable electronic device at various intermediate stages in the manufacturing process according to some embodiments of the present disclosure;

9A-9J are cross-sectional views of a foldable electronic device at various intermediate stages in the manufacturing process according to some embodiments of the present disclosure;

10A-10G are cross-sectional views of a foldable electronic device at various intermediate stages in the manufacturing process according to some embodiments of the present disclosure;

11A-11H are cross-sectional views of a foldable electronic device at various intermediate stages in the manufacturing process according to some embodiments of the present disclosure;

12A-12H are cross-sectional views of a foldable electronic device at various intermediate stages in the manufacturing process according to some embodiments of the present disclosure.

【Symbol Description】

20: Conductive layered structure

22: Substrate

24: Trace material layer

26: Thickening layer

30: Conductive layered structure

32: Substrate

34: Trace material layer

36: Thickening layer

40: Conductive layered structure

42: Substrate

44: Metal layer

50: Conductive layered structure

52: Substrate

54: Conductive layer

56: Metal layer

58: Thickening layer

60: Conductive layered structure

62: Substrate

64: Conductive layer

66: Metal layer

68: Thickening layer

70: Conductive layered structure

72: Substrate

74: Conductive layer

76: Metal layer

78: First polymer layer

80: Second polymer layer

100: Panel

110: Route

112, 114, 116: Area

120: Conductive layered structure

122: Substrate

124: metal layer

126: thickening layer

128: Conductive layer

130: Conductive Laminate

132: Substrate

134: Conductive layer

136: metal layer

138: Thickening layer

140: Conductive Laminate

142: Substrate

144: metal layer

146: Conductive layer

148: Thickening layer

210: Conductive Laminate

212: Substrate

214: Trace material layer

216: Thickening layer

220: Conductive Laminate

222: Substrate

224: Trace material layer

226: First polymer layer

228: Second Polymer Layer

230: Conductive Laminate

232: Substrate

234: catalyst layer

236: Conductive layer

238: Thickening Layer

240: Conductive Laminate

242: Substrate

244: Catalyst Layer

246: Conductive layer

248: First Polymer Layer

250: Second Polymer Layer

310: Conductive Laminate

312: Substrate

314: Metal Layer

316: Thickening layer

318: Conductive layer

330: Conductive Laminate

332: Substrate

334: Metal Layer

336: Conductive layer

338: Thickening Layer

350: Conductive Laminate

352: Substrate

354: Conductive layer

356: Metal Layer

358: Thickening Layer

410: Conductive Laminate

412: Conductive layer

414: Structural layer with double-sided metal film

414A: Metal Layer

414B: Substrate

414C: Metal Layer

416: Thickening layer

418: Conductive layer

430: Conductive Laminate

432: Conductive layer

434: Structural layer with double-sided metal film

434A: Metal Layer

434B: Substrate

434C: Metal Layer

436: Conductive layer

438: Thickening layer

450: Conductive Laminate

452: Metal Layer

454: Structural layer with double-sided conductive film

454A: Conductive layer

454B: Substrate

454C: Conductive layer

456: Metal Layer

458: Thickening layer

502: Substrate

504: Metal Layer

506: photoresist layer

508: Thickening layer

510: photoresist layer

512: Conductive layer

514: photoresist layer

516: Protective layer

522: Substrate

524: metal layer

526: photoresist layer

528: Conductive layer

530: photoresist layer

532: Thickening layer

534: photoresist layer

536: Protective Layer

602: Substrate

604: Conductive layer

606: Metal layer

608: photoresist layer

610: Thickening layer

612: photoresist layer

614: Protective layer

702: Substrate

704: Metal Layer

706: Photoresist layer

708: Conductive layer

710: photoresist layer

712: Protective layer

714: Thickening layer

722: Substrate

724: Conductive layer

726: Metal Layer

728: photoresist layer

730: First Polymer Layer

732: Second Polymer Layer

AA, BB, CC: line

R ₁ , R ₂ : radius of curvature

W ₁ , W ₂ : length

θ ₁ , θ ₂ : angle

Detailed ways

The present disclosure provides many different implementations or examples for implementing the various features of the present disclosure. Specific embodiments 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 description that follows, a second feature is formed on or over a first feature, may include embodiments in which the first and second features form direct contact, and may also be included between the first and second features Additional features may be formed so that the first and second features may not be in direct contact embodiments.

Spatially relative terms such as "below," "below," "lower," "above," "upper," and similar terms may be used herein to describe a The relationship of an element or feature to another element or feature. In addition to the orientation depicted in the figures, spatially relative terms are intended to cover different orientations of the device or apparatus in use or operation. The device or apparatus may be otherwise oriented (rotated 90 degrees or otherwise) and the spatially relative terms used herein may be interpreted accordingly.

Currently, in display devices, metal oxides such as indium tin oxide (ITO) are commonly used as conductive layered materials to form traces. However, metal oxide materials such as indium tin oxide are brittle and poor in flexibility, so the fabricated conductive laminate structure is easily broken. In addition, in the conductive layer structure with nano-silver as the conductive layer, since the bending area of the display device still contains other metal wires in addition to the nano-silver wires, the stress value that the metal material itself can bear is relatively small, and it is easy to generate The deformation causes the resistance value to increase.

There are two key points in the design of the wiring of the foldable electronic device: first, since the bend must withstand tens of thousands of folds, the bend needs to have a certain structural strength; second, the wiring of the foldable electronic device must have Better foldability, ie with a smaller radius of curvature of the bend.

Some embodiments of the present disclosure provide a conductive laminate structure with the addition of a thickened layer on the stretch side at the bend that is most stressed, thereby achieving improved folding properties at smaller radii of curvature.

In some embodiments, the conductive layered structure can be formed as a trace of an electronic device, and applied in a foldable electronic device, for example, an electronic device with a panel, such as a mobile phone, a tablet, a wearable electronic device (such as a smart bracelet) , smart watches, virtual reality devices, etc.), televisions, monitors, laptops, e-books, digital photo frames, navigators, or the like.

1A illustrates a schematic diagram of a panel according to some embodiments of the present disclosure. The panel 100 is a foldable panel, which can be bent along the line AA as the axis (vertical line extending direction), or can be bent along the line BB as the axis (parallel line extending direction). There are a plurality of traces 110 on the edge of the panel 100 for conducting signals. As shown, the location of the traces 110 of the panel 100 has a plurality of locally thickened regions 112 , 114 , and 116 .

1B is a schematic cross-sectional view of a portion of a trace (conductive stack) along line CC in locally thickened region 114 of FIG. 1A , according to some embodiments. The conductive stack 120 includes a substrate 122 , a metal layer 124 over the substrate 122 , a thickened layer 126 over the metal layer 124 , and a conductive layer 128 over the thickened layer 126 . Wherein, the substrate 122 , the metal layer 124 , and the conductive layer 128 are layers that also exist in other regions of the traces 110 . In some embodiments, a thickening layer 126 is added between the metal layer 124 and the conductive layer 128 in a localized area of the trace 110 (eg, in the conductive layer stack 120 ). In other embodiments, the length of the thickened layer 126 along the extending direction of the trace 110 is not greater than the length of the conductive layer 128 .

In some embodiments, the material of the substrate 122 may be polyethyleneterephthalate (PET), cycloolefin polymer (COP), polyimide (PI), polycarbonate ester (polycarbonate, PC), colorless polyimide (Colorless Polyimide, CPI), polyethylene naphthalate (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 118 may be indium tin oxide (ITO), silver nanowires, metal grids, conductive polymers (eg: poly(3,4-ethylenedioxythiophene)/poly(3,4-ethylenedioxythiophene) styrene sulfonic acid) (PEDOT/PSS)), carbon nanotubes, graphene, or the like.

In some embodiments, the material of the thickened layer 126 may be a metal, a non-metal, or a composite conductive material. The metal can be, for example, gold, palladium, silver, copper, nickel, alloys thereof, or combinations thereof. The non-metal can be, for example, a polymer insulating material (eg, a protective layer) or a polymer conductive material (eg, PEDOT/PSS). The composite conductive material can be, for example, nanosilver/carbon black/carbon nanotube/graphene doped metal particles and resins. In some embodiments, the material of the thickened layer has good connection and adhesion to the material of the layer below it to form a good conductor.

In some embodiments, the formation of the thickened layer may be achieved through a patterning process, such as: Lithography, Inkjet Printing (IJP), Spray, Screen printing, Flexo printing ( Flexo printing), or similar.

Referring to FIG. 1C , in other embodiments, the trace portion (conductive stack structure) along the line CC in the locally thickened region 114 of FIG. 1A is the conductive stack structure 130 shown in FIG. 1C . The conductive stack 130 includes a substrate 132 , a conductive layer 134 over the substrate 132 , a metal layer 136 over the conductive layer 134 , and a thickened layer 138 over the metal layer 136 . The substrate 132 , the conductive layer 134 , and the metal layer 136 are also layers in other regions of the trace 110 . In some embodiments, a thickened layer 138 is added over conductive layer 134 and metal layer 136 in localized areas of trace 110 (eg, in conductive stack 130 ). In other embodiments, the length of the thickened layer 138 along the extending direction of the trace 110 is not greater than the length of the conductive layer 134 .

The material of each layer of the conductive stack 130 may be the same as the material of each layer of the conductive stack 120 of FIG. 1B , and may be formed using the same process as described above.

Referring to FIG. 1D , in still other embodiments, the trace portion (conductive stack structure) along the line CC in the locally thickened region 114 of FIG. 1A is the conductive stack structure 140 shown in FIG. 1D . The conductive stack 140 includes a substrate 142 , a metal layer 144 over the substrate 142 , a conductive layer 146 over the metal layer 144 , and a thickened layer 148 over the conductive layer 146 . The substrate 142 , the metal layer 144 , and the conductive layer 146 are also layers in other regions of the traces 110 . In some embodiments, a thickening layer 148 is added over metal layer 144 and conductive layer 146 in localized areas of trace 110 (eg, in conductive layer stack 140 ). In other embodiments, the length of the thickened layer 138 along the extending direction of the trace 110 is not greater than the length of the conductive layer 134 .

The material of each layer of the conductive stack 140 may be the same as the material of each layer of the conductive stack 120 of FIG. 1B , and may be formed using the same process as described above.

Please refer to FIG. 1E , which is an enlarged schematic view of the locally thickened region 114 of FIG. 1A . The width dimension of the traces 110 is W ₁ , the space between the traces is P ₁ , and the dotted line is the bending line when the device is bent. In some embodiments, the area with the thickened layer is in the portion of the trace that is not in the display area. In the first direction (the direction in which the trace extends, that is, the y-direction), the length of the region with the thickened layer is L ₁ .

In some embodiments, in the second direction (the direction perpendicular to the first direction, that is, the x-direction), the width of the thickened layer may be the width of a single trace 110 , that is, the individual thickened layers are located in different in the line. That is, the width dimension of the thickened layer is W ₁ . In other embodiments, when the thickening layer is formed of a non-metallic material, such as a polymer material, an integral thickening layer may be formed within the range of the plurality of traces 110, that is, a single thickening layer A conductive layer covering the plurality of traces 110 . That is, when there are N traces, the width dimension Wt of the thickened layer is equal to or slightly larger than N x W ₁ +(N-1) x P ₁ . Alternatively, the width dimension W _t of the thickened layer is approximately equal to Nx(W ₁ +P ₁ ). Accordingly, the width dimension of the thickened layer in the second direction may range between about W ₁ and about (W ₁ +P ₁ )×N.

FIG. 2A and FIG. 2B are schematic diagrams illustrating a bending state of the bending region of the conductive laminate structure. The length of the area covered by the thickened layer is related to the radius of curvature and the bending angle when bent. In the conductive stack structure 20 shown in FIG. 2A , the conductive stack structure extends along the 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 . In FIG. 2A , the radius of curvature is R ₁ , the angle of bending is θ ₁ , and the length of the thickened layer 26 is W ₁ . In the conductive stack structure 30 of FIG. 2B , the radius of curvature is R ₂ , the bending angle is θ ₂ , the thickened layer 36 is located above the substrate 32 and the trace material layer 34 and has a length W ₂ .

In some embodiments, the length of the thickened layer in the first direction depends on the radius of curvature and the angle of bending of the foldable electronic device. In some embodiments, the radius of curvature of the conductive layer structure 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.

In some embodiments, the conductive layer structure extends along the first direction, and the length of the thickened layer in the bending region in the first direction depends on the curvature radius and the bending angle of the electronic component device during bending, and the thickening layer is thickened. The layer length needs to be at least greater than the arc length range of 180° corresponding to the radius of curvature.

In some embodiments, the length of the thickened layer is greater than 15 millimeters (mm), and the angle between the bending axis and both ends of the thickened layer is 180°˜360° (varies with the length of the thickened layer); compared to Without the conductive layer structure provided with the thickening layer, the conductive layer structure in the embodiments of the present disclosure can increase the amount of stress-strain upon bending by 0.1 to 10%, and the curvature radius of the conductive layer structure can be reduced by 0.5 to 3 mm.

In some embodiments, the conductive layer structure 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 radius of curvature of about 3 mm, the center point of the radius of curvature is the same as the thickened layer. The angle between the two ends of the layer is about 180°.

In other embodiments, the conductive layer structure extends along a first direction, and the length of the thickened layer in the first direction is greater than 15 millimeters. When bent with a radius of curvature of about 5 millimeters, the center point of the radius of curvature is the same as the thickness of the thickened layer. The angle between the two ends of the thick layer is about 180°.

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, such as 0.001, 0.005, 0.01, 0.02, 0.05 , 0.08, 0.1, 0.2, 0.5, 0.8.

In some embodiments, the conductive stacks of the present disclosure may be applied to the routing of foldable electronic devices. A foldable electronic device includes a first portion, a refoldable region connecting the first portion, and a second portion connecting the refoldable region. The traces include a thickened layer in the refoldable area, on the tensile stress bearing side of the foldable electronic device when folded, to reduce the risk of the traces breaking. The angle of the first part and the second part when the foldable electronic device is not folded may be 150-180 degrees or 180-210 degrees, and the angle of the first part and the second part when the foldable electronic device is folded May be 0 degrees-30 degrees or 330 degrees-360 degrees.

When the conductive stack is configured as a conductive trace used in a foldable electronic device, under the action of multiple bending stresses, the resistance change (increase) of the conductive trace should be as small as possible. Once the conductive traces are broken or broken, the resistance of the conductive traces increases or even fails, which may lead to performance degradation or even failure of the foldable electronic device. Where the break as defined herein is conductive, the resistance of the trace increases by more than 10%.

The test results of the bending test of the conductive laminate structure of the embodiment of the present invention will be described below with reference to comparative examples (see FIGS. 3A to 3B ) and experimental examples (see FIGS. 4A to 4C ).

Conducting the Bending Test The conductive laminate structures of the respective Examples and Comparative Examples were tested using a bending machine of the model DMLHP-CS produced by Yuasa Battery Company. The test conditions are that the radius of curvature is 3 mm, the bending frequency is 30 times per minute, and the maximum folding force is 4 Nm. The number of bends and the percent change in resistance for the different conductive stack structures were then recorded.

FIG. 3A is a schematic diagram of the conductive laminate structure 40 in a bent state according to some comparative examples; FIG. 3B is a schematic diagram of the conductive laminate structure 40 in a non-bent state. The conductive stack 40 includes a substrate 42 and a metal layer 44 over the substrate 42 . In addition, the wire length of the conductive laminate structure 40 was 100 μm. In the conductive stack 40, the substrate 42 is made of PET, with a thickness of 50 microns and a Young's modulus of 2˜3GP. The material of the metal layer 44 is a copper layer with a thickness of 0.3 microns and a Young's modulus of 140 Gpa. The dotted line shown in FIG. 3B is the position of the neutral axis at the time of bending.

The following table 1 shows the results of bending tests performed with a radius of curvature of 3 mm and an angle of 180° for the conductive laminate structures of different comparative examples. The metal layer (copper layer) in the comparative example is formed by sputtering or different electroplating processes (ie, electroless plating (1), (2), (3)), respectively.

Table I

It can be seen from Table 1 that after 20,000 times of folding with a radius of curvature of 3 mm, the resistance of the conductive layer structures of the above-mentioned comparative examples increases significantly. The variation of the wiring resistance of the conductive stack structure formed by the electroplating (1), the electroplating (2), and the electroplating (3) processes is greater than 10%.

FIG. 4A is a schematic diagram of the conductive layer structure 50 in a non-bent state according to some experimental examples. The conductive stack 50 includes a substrate 52 , a conductive layer 54 over the substrate 52 , a metal layer 56 over the conductive layer 54 , and a thickened layer 58 over the metal layer 56 . The material of the thickened layer 58 is copper. The dotted line shown in FIG. 4A is the position of the neutral axis at the time of bending.

FIG. 4B is a schematic diagram of the conductive laminate structure 60 in a non-bent state according to some experimental examples. The conductive stack 60 includes a substrate 62 , a conductive layer 64 over the substrate 62 , a metal layer 66 over the conductive layer 64 , and a thickened layer 68 over the metal layer 66 . Among them, the substrate 62 is formed of PET and has a thickness of 50 microns. The conductive layer 64 contains nano-silver material and has a thickness of 0.2-0.5 μm. The material of the metal layer 66 is copper, and the thickness is 0.2-0.5 μm. The thickening layer 68 is a polymer layer, the material is acrylic, and the thickness is 5 to 10 μm. The dotted line shown in FIG. 4B is the position of the neutral axis at the time of bending.

The following Table 2 shows the results of bending tests performed with a radius of curvature of 3 mm and an angle of 180° for the conductive laminate structures of different embodiments as shown in FIG. 4B . The control group is a conductive stack without polymer coating (without thickening layer).

Table II

It can be seen from Table 2 that after 40,000 times of folding, the resistance of the conductive layered structures of the above-mentioned embodiments does not change significantly; on the contrary, the trace resistance of the conductive layered structures without polymer coating increases significantly, representing There is a break in the line. Therefore, the conductive laminates of the Examples have better bending resistance, significantly better than the control laminates without the polymer coating.

FIG. 4C is a schematic diagram of the conductive layer structure 70 in a non-bent state according to some experimental examples. Conductive stack 70 includes substrate 72 , conductive layer 74 over substrate 72 , metal layer 76 over conductive layer 74 , first polymer layer 78 over metal layer 76 , and a first polymer layer 78 over first polymer layer 78 The second polymer layer 80 . That is, in the conductive layer structure 70 , the thickening layer is a multi-layer formed of a heterogeneous polymer, and includes the first polymer layer 78 and the second polymer layer 80 . In the conductive laminate structure 70, the substrate 72 is formed of PET and has a thickness of 50 microns. The conductive layer 74 contains nano-silver material and has a thickness of 100 nm or less. The material of the metal layer 76 is copper, and the thickness is 0.2-0.5 μm. The material of the first polymer layer 78 is optical adhesive (OCA), and the thickness is 50 microns. The material of the second polymer layer 80 is PET, and the thickness is 50 microns. The dashed line shown in FIG. 4C is the position of the neutral axis at the time of bending.

The following Table 3 shows the results of bending tests performed with a radius of curvature of 3 mm and an angle of 180° for the conductive laminate structures of different embodiments. The control group is a conductive stack without polymer coating (without thickening layer). In Table 3, the conductive laminate structure containing the OCA layer/PET layer corresponds to the structure of the example shown in Fig. 4C.

Table 3

It can be seen from Table 3 that after 40,000 times of folding, the resistance of the conductive layer structure of the above-mentioned embodiment with the first polymer layer and the second polymer layer has no obvious change; After 10,000 folds and 200,000 folds, the electrical resistance of the conductive layer structure did not change significantly. That is, there is no case where the conductive layer structure is broken after being folded several times. Thus, the conductive laminates of these examples have better flex resistance, significantly better than the control laminates of the uncoated polymer.

5A-5D illustrate schematic diagrams of conductive stack structures according to some embodiments of the present disclosure.

FIG. 5A shows a conductive stack 210 including a substrate 212 , a layer of trace material 214 over the substrate 212 , and a thickened layer 216 over the layer of trace material 214 . The material of the wiring material layer 214 may be metal, non-metal, or a combination thereof. The material of the thickened layer 216 may be metal, non-metal, or composite conductive material.

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 wiring material layer 214 is 0.05-5, for example, 0.05-0.5, 0.1-1, 0.5-2 , or 2 to 5.

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

In some embodiments, the thickness (unit: μm) of the substrate 212 of the conductive stack structure 210 multiplied by the Young's modulus (unit: Gpa) is about 100-300, and the thickness of the trace material layer 214 is multiplied by the Young's modulus. The value of the modulus is about 20-70, the material of the thickened layer 216 is metal, and the value of the thickness of the thickened layer 216 multiplied by the Young's modulus is about 5-30.

In some embodiments, the value of the thickness of the substrate 212 of the conductive stack structure 210 multiplied by the Young's modulus is about 100-300, and the value of the thickness of the trace material layer 214 multiplied by the Young's modulus is about 20-70, The material of the thickened layer 216 is a non-metal or composite conductive material, and the value of the thickness of the thickened layer 216 multiplied by the Young's modulus is about 2-60.

5B illustrates a conductive stack structure 220 including a substrate 222 , a layer of trace material 224 over the substrate 222 , a first polymer layer 226 over the layer of trace material 224 , and a layer of The second polymer layer 228 . In the conductive stack structure 220, the materials of the substrate 222 and the wiring material layer 224 are similar to those of the substrate 212 and the wiring material layer 214 of the conductive stack structure 210 shown in FIG. 5A. In the conductive layer structure 220 , the thickening layer is a multi-layer formed of heterogeneous polymers, 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 to 10 ⁶ , eg, the first polymer layer 226 is formed of OCA, and the second polymer layer 226 is formed of OCA. Layer 228 is formed of PET. In the conductive layer structure 220, the ratio of the thickness of the first polymer layer 226 to the thickness of the trace material layer 224 is about 30 to 100, and the ratio of the thickness of the second polymer layer 228 to the thickness of the trace 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.

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

5C shows a conductive stack 230 including a substrate 232 , a catalyst layer 234 over the substrate 232 , a conductive layer 236 over the catalyst layer 234 , and a thickening layer 238 over the conductive layer 236 . In conductive stack 230, substrate 232 and thickened layer 238 are similar to substrate 212 and thickened layer 216 in conductive stack 210 shown in FIG. 5A. In some embodiments, the material of the catalyst layer 234 may be any one of metals such as palladium, rhodium, platinum, iridium, osmium, gold, nickel, and iron. In the conductive layer structure 230, the material of the conductive layer 236 is metal, for example, a copper layer can be formed on the catalyst layer 234 through an electroless 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 to 10.

5D illustrates a conductive stack 240 comprising a substrate 242, a catalyst layer 244 over the substrate 232, a conductive layer 246 over the catalyst layer 244, a first polymer layer 248 over the conductive layer 246, and a first polymer layer 248 over the conductive layer 246. Second polymer layer 250 over polymer layer 248 . In conductive stack 240, substrate 242, first polymer layer 248, and second polymer layer 250 are similar to substrate 222, first polymer layer 226, and second polymer layer 220 in conductive stack 220 shown in Figure 5B Polymer layer 228. In some embodiments, the material of the catalyst layer 244 may be any one of metals such as palladium, rhodium, platinum, iridium, osmium, gold, nickel, and iron. In the conductive layer structure 240, the material of the conductive layer 246 is metal, for example, a copper layer can be formed on the catalyst layer 244 through an electroless 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 to 10.

6A to 6F are schematic diagrams illustrating the application of the conductive layer structure to a single-sided foldable electronic device according to some embodiments.

FIG. 6A is a schematic diagram of the conductive laminated structure 310 when folded in a U-shape, and FIG. 6B is a schematic diagram of the conductive laminated structure 310 unfolded.

The conductive stack 310 includes a substrate 312, a metal layer 314 over the substrate 312, and a conductive layer 318 over the metal layer, with a thickened layer 316 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 first to form a thickened layer 316 made of metal or a composite conductive composite, and then a conductive layer 318 containing silver nanowires is coated.

FIG. 6C is a schematic diagram of the conductive layered structure 330 when it is folded in a U-shape, and FIG. 6D is a schematic diagram of the conductive layered structure 330 when it is unfolded.

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

FIG. 6E is a schematic diagram of the conductive laminated structure 350 when folded in a U-shape, and FIG. 6F is a schematic diagram of the conductive laminated structure 350 unfolded.

The conductive stack 350 includes a substrate 352, a conductive layer 354 over the substrate 352, and a metal layer 356 over the conductive layer 354 with a thickened layer 358 over the metal layer 356 formed at the bend. In some embodiments, at the bend, a thickened layer 358 of metal, non-metal, or composite conductive material is locally formed over the metal layer 356 .

7A to 7F are schematic diagrams illustrating the application of the conductive stack structure to a double-sided foldable electronic device according to some embodiments.

FIG. 7A is a schematic diagram of the conductive layered structure 410 when it is folded in an S-shape, and FIG. 7B is a schematic diagram of the conductive layered structure 410 when it is unfolded.

Conductive stack 410 includes structural layer 414 with double-sided metal films, conductive layers 412 and 418 on both sides of structural layer 414 with double-sided metal films, and thickened layer 416 at the bend.

The structural layer 414 with double-sided metal films includes a substrate 414B on which metal layers 414A and 414C are formed. At the bends, thickened layer 416 is located between metal layer 414A and conductive layer 412 , and between metal layer 414C and conductive layer 418 . In some embodiments, at the bend, the metal layer 314 is locally thickened first to form a thickened layer 416 made of metal or composite conductive material, and then the conductive layers 412 and 418 including nano-silver wires are coated.

FIG. 7C is a schematic diagram of the conductive laminated structure 430 when folded in an S-shape, and FIG. 7D is a schematic diagram of the conductive laminated structure 430 unfolded.

The conductive stack structure 430 includes a structural layer 434 with a double-sided metal film, conductive layers 432 and 436 on both sides of the structural layer 434 with a double-sided metal film, and a thickened layer 438 at the bend.

The structural layer 434 with double-sided metal films includes a substrate 434B on which metal layers 434A and 434C are formed. At the bend, thickened layer 438 is located on conductive layers 432 and 436 . In some embodiments, after coating the conductive layers 432 and 436 containing nano-silver wires, at the bend, a thickened layer 438 made of metal, non-metal, or composite conductive material is formed.

FIG. 7E is a schematic diagram of the conductive stack structure 450 when it is folded in an S-shape, and FIG. 7F is a schematic view of the conductive stack structure 450 when it is unfolded.

The conductive stack structure 450 includes a structural layer 454 with a double-sided conductive film (eg, a transparent conductive layer), metal layers 452 and 456 on both sides of the structural layer 454 with a double-sided conductive film, and an additive layer at the bend. Thick layer 458.

The structural layer 454 with double-sided conductive films includes a substrate 454B on which conductive layers 454A and 454C are formed. In some embodiments, at the bends, a thickened layer 458 of metal, non-metal, or composite conductive material is locally formed over the metal layers 452 and 456 .

The following provides a method of manufacturing a folded device having a conductive laminate structure with a thickened layer.

8A to 8I illustrate a process for forming a foldable electronic device, the layers of which sequentially include a single-side metal film (SMF), a selective growth metal (selective growth metal) according to some embodiments. SGM) and a conductive layer, wherein the thickened layer is a metallic material.

As shown in Figure 8A, a substrate 502 with a metal layer 504 is provided. A metallic material such as copper is formed on the substrate 502, possibly using sputtering or electroplating.

As shown in FIG. 8B, a photoresist layer 506 is then formed on the metal layer 504, and the photoresist layer 506 is patterned by exposure and development.

As shown in FIG. 8C , an etching process is then performed to etch a portion of the metal layer 504 that is not covered by the patterned photoresist layer 506 to form a patterned metal layer 504 . The photoresist layer 506 is then stripped.

As shown in FIG. 8D, a photoresist layer 510 is formed between the spaces of the patterned metal layer 504, and exposed and developed. A thickened layer 508 is then selectively grown over the metal layer 504 . In some embodiments, the copper material is formed over the metal layer 504 via sputtering or electroplating.

As shown in FIG. 8E , the photoresist layer 510 is removed, and a conductive layer 512 is provided on the substrate 502 , the metal layer 504 , and the thickened layer 508 . In some embodiments, a conductive material containing silver nanowires or ITO can be formed into the conductive layer 512 by coating.

As shown in FIG. 8F , a photoresist layer 514 is provided, and exposed and developed to form a patterned photoresist layer 514 .

As shown in FIG. 8G, an etch is then performed to etch the conductive layer 512, the thickened layer 508, and the metal layer 504 not covered by the patterned photoresist layer. Therefore, multiple separated traces are formed.

As shown in Figure 8H, the photoresist layer 514 is peeled off.

As shown in FIG. 8I , over coating 516 is provided over substrate 502 , metal layer 504 , thickened layer 508 , and conductive layer 512 . In the structure shown in FIG. 8I, the thickened layer 508 is located between the metal layer 504 and the conductive layer 512 in the trace.

9A to 9J illustrate a process of forming a foldable electronic device, the layers of which sequentially include a single-sided metal film, a conductive layer, and a selectively grown metal, wherein the thickened layer is a metal material, according to some embodiments.

As shown in Figure 9A, a substrate 522 with a metal layer 524 is provided. A metallic material, such as copper, may be formed on the substrate 522 using sputtering or electroplating.

As shown in FIG. 9B, a photoresist layer 526 is formed over the metal layer 524, and is exposed and developed to form a patterned photoresist layer 526.

As shown in FIG. 9C , an etching process is then performed to etch the part of the metal layer 524 that is not covered by the patterned photoresist layer 526 to form a patterned metal layer. The photoresist layer 526 is then stripped.

As shown in FIG. 9D , a conductive layer 528 is provided over the substrate 522 and the metal layer 524 . The conductive material containing silver nanowires or ITO can be formed into the conductive layer 528 by coating.

As shown in FIG. 9E, a photoresist layer 530 is formed, and a patterned photoresist layer 530 is formed by exposure and development.

As shown in FIG. 9F, a thickening layer 532 is provided over the conductive layer in areas not covered by the patterned photoresist layer 530. In some embodiments, copper material may be sputtered or electroplated on conductive layer 528 via selective growth, for example.

As shown in FIG. 9G, the photoresist layer 530 is stripped.

As shown in FIG. 9H , a photoresist layer 534 is formed, and exposed and developed to form a patterned photoresist layer 534 .

As shown in FIG. 9I , etching is then performed to remove the thickened layer 532 , the conductive layer 528 , and the metal layer 524 not covered by the patterned photoresist layer 534 . Therefore, multiple separated traces are formed. The photoresist layer 534 is then stripped.

As shown in FIG. 9J , a protective layer 536 is provided over the substrate 522 , the metal layer 524 , the conductive layer 528 , and the thickened layer 532 . In the structure shown in FIG. 9J, thickened layer 532 is located over both metal layer 524 and conductive layer 528 in the trace.

10A to 10G illustrate a process for forming a foldable electronic device, the layers of which sequentially include a conductive layer, a single-sided metal film, and a selectively grown metal, wherein the thickened layer is a metal material, according to some embodiments.

As shown in FIG. 10A , a substrate 602 including a conductive layer 604 (transparent conductive film) is first provided, and then a metal layer 606 is provided on the conductive layer 604 . In some embodiments, the copper material may be formed over conductive layer 604 via sputtering or electroplating.

As shown in FIG. 10B , a photoresist layer 608 is formed, and exposed and developed to form a patterned photoresist layer 608 .

As shown in FIG. 10C , a thickened layer 610 is provided over the portion of the metal layer 606 that is not covered by the photoresist layer 608 . In some embodiments, the copper material may be disposed over the metal layer 606 via selective growth of the metal layer, such as sputtering or electroplating.

As shown in Figure 10D, the photoresist layer 608 is stripped.

As shown in FIG. 10E , a photoresist layer 612 is disposed on the thickened layer 610 and the metal layer 606 , and is exposed and developed to form a patterned photoresist layer 612 .

As shown in FIG. 10F , an etch is then performed to remove the thickened layer 610 , the metal layer, and the conductive layer 604 not covered by the patterned photoresist layer 612 . Therefore, multiple separated traces are formed.

As shown in FIG. 10G , the metal layer 606 in the middle area (eg, the display area that will later be formed as the electronic device) is removed. A protective layer 614 is then disposed over the thickened layer 610 , the metal layer 606 , and the conductive layer 604 . In the structure shown in FIG. 10G, thickened layer 610 is located over both conductive layer 604 and metal layer 606 in the trace.

11A to 11H illustrate a process for forming a foldable electronic device, the layers of which sequentially include a metal layer, a conductive layer, and a thickened layer, wherein the thickened layer is a non-metallic material, such as a polymer material, according to some embodiments. .

As shown in FIG. 11A, a substrate 702 with a metal layer 704 is provided. A metallic material, such as copper, may be formed on the substrate 702 using sputtering or electroplating.

As shown in FIG. 11B , a photoresist layer 706 is formed over the metal layer 704 and exposed and developed to form a patterned photoresist layer 706 .

As shown in FIG. 11C, the metal layer 704 not covered by the patterned photoresist layer 706 is etched. The photoresist layer 706 is then stripped.

As shown in FIG. 11D , a conductive layer 708 is provided over the substrate 702 and the metal layer 704 . The conductive material containing silver nanowires or ITO can be formed into the conductive layer 708 by coating.

As shown in FIG. 11E, a photoresist layer 710 is formed on the conductive layer 708, and a patterned photoresist layer 710 is formed by exposure and development.

As shown in FIG. 11F , etching is then performed to remove 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.

As shown in FIG. 11G, the photoresist layer 710 is then stripped. In a subsequent process, a protective layer 712 is formed on each trace. The protective layer 712 may be formed of a polymer material.

As shown in FIG. 11H , a thickened layer 714 is then formed over the protective layer 712 . Thickening 714 may be formed of another polymeric material than protective layer 712 .

FIGS. 12A to 12H illustrate a process for forming a foldable electronic device, the layers of which include a conductive layer, a metal layer, and a thickened layer in sequence, wherein the thickened layer is a non-metallic material, such as a polymer material, according to some embodiments. .

As shown in FIG. 12A , a substrate 722 including a conductive layer 724 is first provided, and the conductive layer 724 may, for example, include silver nanowires. In some embodiments, over the conductive layer 724 is a protective layer (not shown). A metal layer 726 is then disposed over the conductive layer 724. In some embodiments, the copper material may be formed over conductive layer 724 via sputtering or electroplating.

As shown in FIG. 12B, a photoresist layer 728 is formed over the metal layer 726, and is exposed and developed to form a patterned photoresist layer 728.

As shown in FIG. 12C, the metal layer 726 and the conductive layer 724 not covered by the patterned photoresist layer 728 are etched. Thus, multiple separate traces are formed.

As shown in Figure 12D, the photoresist layer 728 in the middle region is stripped.

As shown in Figure 12E, the metal layer 726 in the middle region is removed.

As shown in Figure 12F, the photoresist layer 728 is stripped.

As shown in FIG. 12G, a first polymer layer 730 is formed over the various traces and over the conductive layer 724.

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

The conductive layer structure of the present disclosure enables the foldable electronic device to have a smaller bending radius of curvature, enhances the foldability, and can still have better reliability of the wiring after multiple bending, improves the quality of the product and increases the the life of the device.

Several embodiments have been summarized above so that those skilled in the art may better understand the various aspects of the present disclosure. Those skilled in the art should appreciate that they may use the present disclosure as a basis for designing or modifying other processes and structures for carrying out the same purposes and/or achieving 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 that they may make various changes, substitutions, and alterations without departing from the spirit and scope of the present disclosure.

Claims (18)

1. A conductive layer stack, comprising:

a conductive layer extending along a first direction; and

and the thickening layer is arranged above or below the conductive layer, and the conductive layer stack can bear the fracture of more than 40000 times when the conductive layer stack is bent by 180 degrees in a direction perpendicular to or parallel to the first direction, wherein the curvature radius R is 3 mm.

2. The conductive stack of claim 1, wherein the length of the thickening layer in the first direction is greater than 9 mm and does not exceed the length of the conductive layer extending in the first direction.

3. The conductive stack of claim 2, wherein the length of the thickening layer in the first direction is greater than 15 mm and does not exceed the length of the conductive layer extending in the first direction.

4. The conductive layer stack of claim 1, wherein an angle between a bending axis of the conductive layer stack and two ends of the thickening layer is 180 ° to 360 °.

5. The conductive stack of claim 1, wherein a ratio of a length of the thickening layer in the first direction to a length of the conductive layer extending along the first direction is 0.001-1.

6. The conductive stack of claim 1, wherein the thickening layer increases the amount of stress strain in the conductive stack when the conductive stack is bent by 0.1 to 10%, and the radius of curvature of the conductive stack is reduced by 0.5 to 3 mm.

7. The conductive stack of claim 1, wherein the thickening layer is located on a stress-stretching side of the conductive stack when the conductive stack is bent.

8. A foldable electronic device, comprising the conductive stack of any one of claims 1 to 7.

9. A foldable electronic device, comprising:

a display area; and

a non-display area located outside the display area, wherein the non-display area has a plurality of wires extending along a first direction, each of the plurality of wires includes:

a substrate, and

a conductive layer over the substrate;

the non-display area has a local thickened area including a bending part of the foldable electronic device, and each of the plurality of wires in the local thickened area further includes a thickened layer above or below the conductive layer and located on a stress stretching side of the foldable electronic device when the foldable electronic device is bent.

10. The foldable electronic device of claim 9, wherein the locally thickened region has a width extending along a second direction perpendicular to the first direction, and one of the traces has a width W₁The distance between the routing lines is P₁The number of the routing lines is N, and the width range of the local thickening area is between W₁To (W)₁+P₁) x N, respectively.

11. The foldable electronic device of claim 9, wherein the length of the thickening layer along the first direction is greater than 3 mm.

12. The foldable electronic device of claim 9, wherein the thickening layer is formed of a metal material, and a ratio of the thickness of the thickening layer to the thickness of the conductive layer is 0.05-5.

13. The foldable electronic device of claim 9, wherein the thickening layer is formed of a non-metallic material or a composite conductive material, and a ratio of the thickness of the thickening layer to the thickness of the conductive layer is 0.1-50.

14. The foldable electronic device of claim 9, wherein the thickening layer is made of a metal material, and 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.

15. The foldable electronic device of claim 9, wherein 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 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 is 2-60.

16. The foldable electronic device of claim 9, wherein the thickening layer comprises:

a first polymer layer; and

a second polymer layer over the first polymer layer, wherein the material of the first polymer layer is different from the material of the second polymer layer.

17. The foldable electronic device of claim 16, wherein the ratio of the young's modulus of the first polymer layer to the young's modulus of the second polymer layer is 10³～10⁶。

18. The foldable electronic device of claim 16, wherein a ratio of the thickness of the first polymer to the thickness of the conductive layer is 30 to 100, a ratio of the thickness of the second polymer to the thickness of the conductive layer is 30 to 100, and a ratio of the thickness of the first polymer to the thickness of the second polymer is 0.5 to 2.

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