electronic equipment

Abstract

To provide an electronic apparatus including a wire that is broken less easily when compressive stress is applied.SOLUTION: An electronic apparatus includes a flexible insulating base material, a plurality of wires disposed on the insulating base material, and a plurality of electric elements connected to the wires. The insulating base material includes a plurality of island-shaped parts where the electric elements are disposed, and a plurality of band-shaped parts for connecting the adjacent island-shaped parts, where the wires are disposed. Each of the band-shaped parts includes a meandering curved part, and a linear part connecting the curved part and the island-shaped part. The curved part includes a first curved part, a second curved part, and a third curved part. The width of the second curved part is smaller than that of the third curved part.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] FIELD An embodiment of the present invention relates to an electronic device. [Background technology]

[0002] In recent years, the use of flexible substrates that are flexible and stretchable has been studied in various fields. For example, a flexible substrate on which electrical elements are arranged in a matrix may be attached to the housing of an electronic device, the curved surface of the human body, or the like. Examples of electrical elements that may be used include various sensors such as touch sensors and temperature sensors, and display elements.

[0003] In flexible substrates, measures must be taken to prevent damage to the wiring due to stress caused by bending or expansion / contraction. For example, measures such as providing honeycomb-shaped openings in the substrate that supports the wiring, or forming the wiring in a meandering shape have been proposed. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-198101 [Patent Document 2] Japanese Patent Application Laid-Open No. 2015-198102 [Patent Document 3] Japanese Patent Application Laid-Open No. 2017-118109 [Patent Document 4] Japanese Patent Application Laid-Open No. 2017-113088 Summary of the Invention [Problem to be solved by the invention]

[0005] An object of this embodiment is to provide an electronic device having wiring that is less likely to break when compressive stress is applied. [Means for solving the problem]

[0006] According to one embodiment, an electronic device includes an insulating substrate having elasticity, a plurality of wirings arranged on the insulating substrate, and a plurality of electrical elements connected to the wirings, the insulating substrate having a plurality of island-shaped portions on which the electrical elements are located, and a plurality of strip-shaped portions on which the wirings are located and connecting adjacent island-shaped portions, the strip-shaped portions each including a meandering curved portion and a straight portion connecting the curved portion and the island-shaped portion, the curved portion including a first curved portion, a second curved portion, and a third curved portion, the first curved portion including a straight portion connecting the island-shaped portion and the island-shaped portion, the first curved portion including a straight portion connecting the island-shaped portion and the island-shaped portion, the first curved portion including a straight portion connecting the island-shaped portion and the island-shaped portion, the first curved portion including a straight portion connecting the island-shaped portion and the island-shaped portion, the second ... The curved portion is connected to the straight portion and curves away from the straight portion in both a first direction in which the straight portion extends and a second direction perpendicular to the first direction, the second curved portion is connected to the first curved portion and curves away from the straight portion in both directions, the third curved portion is connected to the second curved portion and curves away from the straight portion in the first direction and towards the straight portion in the second direction, and the width of the second curved portion is smaller than the width of the third curved portion. According to one embodiment, an electronic device includes an insulating substrate having elasticity, a plurality of wirings arranged on the insulating substrate, and a plurality of electrical elements connected to the wirings, the insulating substrate having a plurality of island-shaped portions on which the electrical elements are located, and a plurality of strip-shaped portions on which the wirings are located and connecting adjacent island-shaped portions, the plurality of strip-shaped portions each including a meandering curved portion and a straight portion connecting the curved portion and the island-shaped portion, the curved portion including a first curved portion, a second curved portion, and a third curved portion, the first curved portion is connected to the straight portion and curved away from the straight portion in both a first direction in which the straight portion extends and a second direction perpendicular to the first direction, the second curved portion is connected to the first curved portion and curved away from the straight portion in both directions, the third curved portion is connected to the second curved portion and curved away from the straight portion in the first direction and towards the straight portion in the second direction, and the radius of curvature of the second curved portion is larger than the radius of curvature of the third curved portion. [Brief explanation of the drawings]

[0007] [Figure 1]FIG. 1 is a schematic plan view of an electronic device according to an embodiment. [Figure 2] FIG. 2 is an enlarged plan view of a portion of the flexible substrate shown in FIG. [Figure 3] FIG. 3 is a schematic cross-sectional view of a portion of the flexible substrate indicated by AB in FIG. [Figure 4] FIG. 4 is a schematic cross-sectional view of a portion of the flexible substrate indicated by CD in FIG. [Figure 5] FIG. 5 is a schematic cross-sectional view of a portion of the flexible substrate indicated by IJ in FIG. [Figure 6] FIG. 6 is a diagram illustrating an example of a structure applied to the first portion. [Figure 7] FIG. 7 is a diagram for explaining how compressive stress is applied when compressive stress is applied to the structure shown in FIG. [Figure 8] FIG. 8 is a diagram for explaining another example of the structure applied to the first portion. [Figure 9] FIG. 9 is a diagram for explaining yet another example of the structure applied to the first portion. [Figure 10] FIG. 10 is a diagram for explaining an example of sample conditions. [Figure 11] FIG. 11 shows the results of the compression test of each sample. DETAILED DESCRIPTION OF THE INVENTION

[0008] The present embodiment will be described below with reference to the drawings. The disclosure is merely an example, and appropriate modifications that a person skilled in the art can easily make while maintaining the gist of the invention are naturally included within the scope of the present invention. Furthermore, the drawings may be schematic in terms of the width, thickness, shape, etc. of each part compared to the actual embodiment for clarity of explanation, but these are merely examples and are not intended to limit the interpretation of the present invention. Furthermore, in this specification and each drawing, components that perform the same or similar functions as those described above with reference to the previous drawings are designated by the same reference numerals, and redundant detailed descriptions may be omitted as appropriate.

[0009] FIG. 1 is a schematic plan view of an electronic device 1 according to this embodiment. In this embodiment, a first direction D1, a second direction D2, and a third direction D3 are defined as shown. The first direction D1 and the second direction D2 are parallel to the main surface of the electronic device 1 and intersect with each other. The third direction D3 is perpendicular to the first direction D1 and the second direction D2 and corresponds to the thickness direction of the electronic device 1. In this embodiment, the first direction D1 and the second direction D2 intersect perpendicularly, but they may intersect at an angle other than perpendicular. In this specification, the direction toward the tip of the arrow indicating the third direction D3 is referred to as "up," and the direction opposite from the tip of the arrow is referred to as "down." Furthermore, it is assumed that an observation position for observing the electronic device 1 is located at the tip of the arrow indicating the third direction D3. Viewing the D1-D2 plane defined by the first direction D1 and the second direction D2 from this observation position is referred to as planar view.

[0010] The electronic device 1 includes a flexible substrate 2, a circuit board 3, and a controller 4. The circuit board 3 is, for example, a flexible printed circuit board, and is electrically connected to each terminal in a terminal area TA of the flexible substrate 2. The controller 4 is mounted on the circuit board 3, but may also be mounted on the flexible substrate 2.

[0011] The flexible substrate 2 has flexibility and stretchability. A specific example of a configuration for realizing stretchability will be described later. The flexible substrate 2 includes a plurality of scanning lines 11, a plurality of signal lines 12, a plurality of electrical elements 13, a scanning line driver DR1, a signal line driver DR2, etc. The plurality of scanning lines 11 each extend in a first direction D1 and are aligned in a second direction D2. The plurality of scanning lines 11 are each connected to the scanning line driver DR1. The plurality of signal lines 12 each extend in the second direction D2 and are aligned in the first direction D1. The plurality of signal lines 12 are each connected to the signal line driver DR2. The plurality of electrical elements 13 are each located at the intersections of the scanning lines 11 and the signal lines 12 and are electrically connected to the scanning lines 11 and the signal lines 12. The functions of the electrical elements 13 will be described in detail below.

[0012] Fig. 2 is an enlarged plan view of a portion of the flexible substrate 2 shown in Fig. 1. In addition to the above, the flexible substrate 2 includes an insulating base material 14 that supports the scan lines 11 and the signal lines 12.

[0013] The insulating substrate 14 is formed in a mesh shape. In a plan view, the insulating substrate 14 has a plurality of first portions (line portions) PT1 extending in a first direction D1 and arranged side by side in a second direction D2, a plurality of second portions (line portions) PT2 extending in the second direction D2 and arranged side by side in the first direction D1, and a plurality of island-shaped portions IL provided at intersections between the first portions PT1 and the second portions PT2. In a plan view, the first portions PT1 and the second portions PT2 are each formed in a wave shape. The island-shaped portions IL are connected to the first portions PT1 and the second portions PT2. The insulating substrate 14 is flexible and stretchable and can be formed of, for example, polyimide, but is not limited to this example.

[0014] The scanning lines 11 are arranged on a first portion PT1 of the insulating substrate 14 in a wavy pattern. The signal lines 12 are arranged on a second portion PT2 of the insulating substrate 14 in a wavy pattern. The scanning lines 11 and the signal lines 12 are an example of wiring provided in the flexible substrate 2 (or in the electronic device 1 including the flexible substrate 2). The scanning lines 11 and the signal lines 12 can be formed of, for example, a metal material or a transparent conductive material, and may have a single-layer structure or a multilayer structure. In addition to the scanning lines 11 and the signal lines 12, the flexible substrate 2 may also include other types of wiring, such as power lines for supplying power to the electrical elements 13.

[0015] The scanning line 11 has a first portion 11A indicated by a solid line and a second portion 11B indicated by a dashed line. The second portion 11B overlaps with the electrical element 13. The first portion 11A and the second portion 11B are disposed on different layers and are electrically connected via contact holes CH1 and CH2.

[0016] The scanning line 11 supplies a scanning signal to the electric element 13. For example, if the electric element 13 is a device that outputs a signal, such as a sensor, the output signal from the electric element 13 is supplied to the signal line 12. Also, for example, if the electric element 13 is a device that operates in response to an input signal, such as a light-emitting element or an actuator, a drive signal is supplied to the signal line 12.

[0017] The electrical element 13 is located on the island-like portion IL. The electrical element 13 is smaller than the island-like portion IL, and in FIG. 2, the island-like portion IL extends beyond the edge of the electrical element 13. For example, the electrical element 13 may be a sensor, a semiconductor element, an actuator, or the like. For example, the sensor may be an optical sensor that receives visible light or near-infrared light, a temperature sensor, a pressure sensor, or a touch sensor. For example, the semiconductor element may be a light-emitting element, a light-receiving element, a diode, or a transistor. When the electrical element 13 is a light-emitting element, a flexible display having flexibility and stretchability can be realized. For example, a light-emitting diode having a size of approximately 100 μm, such as a mini-LED or a micro-LED, or an organic electroluminescence element can be used as the light-emitting element. When the electrical element 13 is an actuator, for example, a piezoelectric element can be used. Note that the electrical element 13 is not limited to the example shown here, and elements having various other functions can also be used. The electrical element 13 may be a capacitor, a resistor, or the like. Furthermore, the arrangement position and shape of the electrical element 13 are not limited to the example shown in FIG. 2.

[0018] In this embodiment, the first and second portions PT1 and PT2 of the insulating substrate 14, the scanning line 11, the signal line 12, and the first and second organic insulating layers 15 and 16 (described later) are collectively referred to as the line portion LP, and the island-shaped portion IL of the insulating substrate 14, the inorganic insulating layer 19 (described later), and the electrical element 13 are collectively referred to as the island-shaped portion IP. In plan view, the line portion LP includes a plurality of wavy first line portions LP1 extending in the first direction D1 and arranged side by side in the second direction D2, and a plurality of wavy second line portions LP2 extending in the second direction D2 and arranged side by side in the first direction D1. The island-shaped portion IP is located at the intersection of the first line portion LP1 and the second line portion LP2. The first line portion LP1 includes the first portion PT1 of the insulating substrate 14 and the scanning line 11. The second line portion LP2 includes the second portion PT2 of the insulating substrate 14 and the signal line 12. In addition, in the region surrounded by two adjacent first line portions LP1 and two adjacent second line portions LP2, the insulating base material 14 is not formed, and an opening OP is formed. In other words, the opening OP can also be said to be the region surrounded by two adjacent first portions PT1 and two adjacent second portions PT2. The openings OP are arranged in a matrix in the first direction D1 and the second direction D2.

[0019] FIG. 3 is a schematic cross-sectional view of a part of the flexible substrate 2 indicated by AB in FIG. In addition to the above elements, the flexible substrate 2 further comprises a first organic insulating layer 15, a second organic insulating layer 16, a first elastic member EM1, and a second elastic member EM2.

[0020] The first telescopic member EM1 has an outer surface EM1A and an inner surface EM1B opposite the outer surface EM1A. The first line portion LP1 is located on the inner surface EM1B. The first line portion LP1 has a first side surface SS1, a second side surface SS2 opposite the first side surface SS1, and a top surface US.

[0021] The first portion PT1 of the insulating substrate 14 is located on the inner surface EM1B of the first elastic member EM1. The first organic insulating layer 15 covers the insulating substrate 14. The scanning lines 11 are located on the first organic insulating layer 15. The second organic insulating layer 16 covers the first organic insulating layer 15 and the scanning lines 11. The first organic insulating layer 15 and the second organic insulating layer 16 are both formed of an organic material.

[0022] The second elastic member EM2 has an outer surface EM2A and an inner surface EM2B opposite the outer surface EM2A. The second elastic member EM2 covers the first side surface SS1, the second side surface SS2, and the top surface US of the first line portion LP1. That is, the second elastic member EM2 covers the scanning line 11, the insulating substrate 14, the first organic insulating layer 15, and the second organic insulating layer 16. The second elastic member EM2 contacts the insulating substrate 14, the first organic insulating layer 15, and the second organic insulating layer 16 of the first line portion LP1. The inner surface EM2B of the second elastic member EM2 contacts the inner surface EM1B of the first elastic member EM1 at the opening OP. The first elastic member EM1, the insulating substrate 14, the scanning line 11, and the second elastic member EM2 overlap in the third direction D3. The insulating substrate 14 and the scanning line 11 are located between the first elastic member EM1 and the second elastic member EM2.

[0023] Of the second telescopic member EM2, the portions overlapping with the first portions PT1 and second portions PT2 and the island-shaped portions IL are referred to as first portions EM21, and the portions located between the first portions PT1 and second portions PT2, i.e., the portions overlapping with the opening OP, are referred to as second portions EM22. The second portions EM22 are in contact with the first telescopic member EM1. The first telescopic member EM1 and the second telescopic member EM2 can be formed, for example, from a stretchable, transparent resin material.

[0024] FIG. 4 is a schematic cross-sectional view of a part of the flexible substrate 2 indicated by CD in FIG. The second line portion LP2 is located on the inner surface EM1B of the first telescopic member EM1. The second line portion LP2 has a first side surface SS1, a second side surface SS2 opposite to the first side surface SS1, and an upper surface US.

[0025] The second portion PT2 of the insulating substrate 14 is located on the inner surface EM1B of the first elastic member EM1. The first organic insulating layer 15 covers the insulating substrate 14. The second organic insulating layer 16 covers the first organic insulating layer 15. The signal line 12 is located on the second organic insulating layer 16. The second elastic member EM2 covers the first side surface SS1, the second side surface SS2, and the top surface US of the second line portion LP2 and is in contact with the inner surface EM1B of the first elastic member EM1 at the opening OP. That is, the second elastic member EM2 covers and is in contact with the insulating substrate 14, the first organic insulating layer 15, the second organic insulating layer 16, and the signal line 12. The first elastic member EM1, the insulating substrate 14, the signal line 12, and the second elastic member EM2 overlap in the third direction D3. The insulating substrate 14 and the signal line 12 are located between the first elastic member EM1 and the second elastic member EM2.

[0026] FIG. 5 is a schematic cross-sectional view of a part of the flexible substrate 2 indicated by IJ in FIG. The electrical element 13 is disposed on an island-shaped portion IL of the insulating substrate 14. An inorganic insulating layer 19 (passivation layer) is disposed between the electrical element 13 and the island-shaped portion IL. The inorganic insulating layer 19 is formed in an island shape overlapping the electrical element 13 (or the island-shaped portion IL) in a plan view. The first portion 11A is disposed on the first organic insulating layer 15 and is covered with the second organic insulating layer 16. The second portion 11B is disposed on the inorganic insulating layer 19 and is electrically connected to the electrical element 13. In the example shown in FIG. 5, both end portions of the second portion 11B are covered with the first organic insulating layer 15.

[0027] Contact holes CH1 and CH2 are provided in the first organic insulating layer 15. The first portion 11A is electrically connected to the second portion 11B via connection members CM1 and CM2 disposed in the contact holes CH1 and CH2. The connection members CM1 and CM2 may be part of the first portion 11A, or may be provided separately from the first portion 11A.

[0028] In this manner, an island-shaped inorganic insulating layer 19 is disposed between the electrical element 13 and the insulating base material 14. This inorganic insulating layer 19 functions as a protective film that prevents moisture and the like from penetrating into the electrical element 13 and the second portion 11B of the scan line 11. This improves the reliability of the flexible substrate 2. Furthermore, although inorganic films are generally more prone to cracking than organic films, because the inorganic insulating layer 19 is not provided below the first portion 11A of the scan line 11, disconnection at the first portion 11A is suppressed. The same applies to the signal line (not shown). Furthermore, the stretchability and flexibility of the flexible substrate 2 are less likely to be hindered compared to when the inorganic insulating layer 19 is provided over the entire flexible substrate 2.

[0029] Furthermore, in the scan line 11, the second portion 11B overlapping with the electrical element 13 is disposed in a different layer from the first portion 11A, thereby improving the degree of freedom in designing the vicinity of the electrical element 13. Furthermore, the contact holes CH1 and CH2 are provided above the inorganic insulating layer 19, thereby preventing poor connection at the connection position between the first portion 11A and the second portion 11B. Furthermore, the island-shaped portion IL of the insulating base material 14 is disposed below the electrical element 13. This allows the electrical element 13 to be well supported.

[0030] The island-shaped portion IL is located on the inner surface EM1B of the first telescopic member EM1. The second telescopic member EM2 covers the electrical element 13. The first telescopic member EM1, the island-shaped portion IL, the electrical element 13, and the second telescopic member EM2 overlap in the third direction D3.

[0031] Next, we will explain a method for controlling the wiring strain (compressive strain) when the first portion PT1 is compressed. Here, we prepared three samples (Sample 1, Sample 2, and Sample 3) described below, and performed a compression test on each to calculate the wiring strain.

[0032] FIG. 6 is a diagram illustrating the structure of Sample 1. The structure of Sample 1 shown in FIG. 6 is a structure referred to as a basic structure. A strip portion PT10 connecting island portion IL1 and island portion IL2 meanders in an S-shape. A scanning line 11 is formed across island portion IL1, strip portion PT10, and island portion IL2. The scanning line 11 formed on strip portion PT10 meanders according to the shape of strip portion PT10. Strip portion PT10 has curved portions PT11 to PT13 that form the S-shape meandering portion, and a straight portion PT14 that connects the S-shape meandering portion to island portions IL1 and IL2. Curved portion PT11 is connected to straight portion PT14 and curves away from straight portion PT14 in both the direction in which straight portion PT14 extends and the direction perpendicular to that direction. The curved portion PT12 is connected to the curved portion PT11 and curves away from the straight portion PT14 in both the direction in which the straight portion PT14 extends and the direction perpendicular to that direction. The curved portion PT13 is connected to the curved portion PT12 and curves away from the straight portion PT14 in the direction in which the straight portion PT14 extends and curves toward the straight portion PT14 in the direction perpendicular to that direction.

[0033] The radii of curvature along the inner periphery of each of the curved portions PT11 to PT13 are defined as r1 to r3, respectively. In the structure of sample 1 shown in FIG. 6, the radii of curvature r1 to r3 have the same value. The line widths of the curved portions PT11 to PT13 (more specifically, the distance between the midpoint of the inner periphery and the midpoint of the outer periphery of each of the curved portions PT11 to PT13) and the line width of the straight portion PT14 are defined as W1 to W4, respectively. In the structure of sample 1 shown in FIG. 6, the line widths W1 to W4 have the same value. The linear distance from one end of the scanning line 11 located on the island portion IL1 to the other end of the scanning line 11 located on the island portion IL2 (or the pitch between the island portions IL1 and IL2) is defined as L1. The total length of the scanning line 11 spanning the island portion IL1, the strip portion PT10, and the island portion IL2 is defined as L2. The hinge length ratio L' is defined as L2 / L1.

[0034] The results of the compression test (wiring strain) will be described later, but it was confirmed that when compressive stress was applied in a direction that brought island-shaped portion IL1 and island-shaped portion IL2 of sample 1 closer together, the greatest compressive stress was applied to the portion shown by diagonal lines in Figure 7, in other words, the outer peripheral portion of curved portion PT12, which is slightly shifted toward curved portion PT12 from the boundary between curved portions PT12 and PT13. In other words, it was confirmed that if first portion PT1 (band-shaped portion PT10) were to break when compressive stress was applied, the breakage was most likely to occur in the portion shown by diagonal lines in Figure 7. Hereinafter, the portion shown by diagonal lines in Figure 7 may be referred to as the stress concentration area.

[0035] Fig. 8 is a diagram for explaining the structure of Sample 2. Here, only the parts that are different from the basic structure shown in Fig. 6 will be explained, and explanation of the same parts will be omitted. The structure of Sample 2 shown in FIG. 8 differs from the basic structure shown in FIG. 6 in that the line width W of the strip portion PT10 gradually decreases (becomes thinner) from the center O of the S-shaped meandering portion toward the curved portion PT12. That is, the line width W2 of the curved portion PT12 is smaller than the line width W3 of the curved portion PT13. In the structure of Sample 2 shown in FIG. 8, the line width W1 of the curved portion PT11 and the line width W4 of the straight portion PT14 have the same value. The line width W1 of the curved portion PT11 and the line width W4 of the straight portion PT14 are smaller than the line width W2 of the curved portion PT12 and have the same value as the line width of the boundary between the curved portions PT11 and PT12. In the structure of Sample 2 shown in FIG. 8, the radii of curvature r1 to r3 have the same value.

[0036] 9 is a diagram for explaining the structure of Sample 3. Here, only the parts that are different from the basic structure shown in FIG. 6 will be explained, and explanations of the same parts will be omitted. The structure of Sample 3 shown in Fig. 9 differs from the basic structure shown in Fig. 6 in that the radius of curvature r2 of curved portion PT12 is larger than the radius of curvature r3 of curved portion PT13. In the structure of Sample 3 shown in Fig. 9, the radius of curvature r1 of curved portion PT11 and the radius of curvature r3 of curved portion PT13 have the same value. In addition, in the structure of Sample 3 shown in Fig. 9, the line widths W1 to W4 have the same value.

[0037] FIG. 10 is a diagram for explaining example conditions (specific numerical values) of the radius of curvature r2 and the line width W2 of the curved portion PT12 of Sample 1, Sample 2, and Sample 3. In FIG. The curvature radius r2 of the curved portion PT12 of Sample 1 shown in FIG. 6 is 15 μm, and the line width W2 of the curved portion PT12 is 30 μm. The curvature radius r2 of the curved portion PT12 of Sample 2 shown in FIG. 8 is 15 μm, and the line width W2 of the curved portion PT12 is 10 μm. The curvature radius r2 of the curved portion PT12 of sample 3 shown in FIG. 9 is 45 μm, and the line width W2 of the curved portion PT12 is 30 μm.

[0038] FIG. 11 shows the results of a compression test for each sample. In this compression test, the wiring strain of the first portion PT1 (wiring strain of the strip portion PT10) was calculated when a compressive stress with a compression rate of 10% was applied in a direction that brought the island-shaped portion IL1 and the island-shaped portion IL2 of each sample closer to each other. The compression rate is one indicator of the magnitude of the compressive stress. For example, it is calculated by dividing the difference (compression amount) between the linear distance L1 before the compressive stress was applied and the linear distance L1' after the compressive stress was applied by the linear distance L1, and then multiplying the result by 100. In this compression test, since the compression rate was assumed to be 10% as described above, a compressive stress of a magnitude that reduced the linear distance L1 to 0.9*L1 (=L1') was applied in a direction that brought the island-shaped portion IL1 and the island-shaped portion IL2 of each sample closer to each other. Furthermore, the wiring strain of the first portion PT1 indicates the degree of strain of the first portion PT1 when compressive stress is applied to the first portion PT1, with the state in which no compressive stress is applied to the first portion PT1 being considered as a state in which there is no wiring strain (wiring strain 0%), and it has been found that the greater this wiring strain, the more likely it is to break when compressive stress is applied.

[0039] 11, the results of the compression test described above showed that the wiring strain of Sample 1 was 20%, the wiring strain of Sample 2 was 5%, and the wiring strain of Sample 3 was 10%. In other words, according to the compression test, it was confirmed that the basic structure of Sample 1 had the highest wiring strain and was likely to break when compressive stress was applied, whereas the structures of Samples 2 and 3 had lower wiring strain than the basic structure and were less likely to break even when compressive stress was applied.

[0040] More specifically, it was confirmed that by making the line width W2 of the curved portion PT12, which includes the stress concentration point, smaller than the line width W3 of the curved portion PT13, as in the structure of sample 2, the wiring distortion is reduced, and a structure that is less likely to break even when compressive stress is applied can be realized.

[0041] Furthermore, it was confirmed that by making the radius of curvature r2 of the curved portion PT12, which includes the stress concentration point, larger than the radius of curvature r3 of the curved portion PT13, as in the structure of sample 3, wiring distortion is reduced, and a structure that is less likely to break even when compressive stress is applied can be realized.

[0042] From the above results, it was confirmed that the wiring strain in the first portion PT1 can be controlled by the radius of curvature r2 and the line width W2 of the curved portion PT12 including the stress concentration point. Note that although the method for controlling the wiring strain in the first portion PT1 has been described here, the wiring strain in the second portion PT2 can also be controlled by a similar method.

[0043] As described above, according to this embodiment, it is possible to provide an electronic device having wiring that is less likely to break when compressive stress is applied.

[0044] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the inventions and their equivalents as defined in the claims. [Explanation of symbols]

[0045] 1...electronic device, 2...flexible substrate, 3...circuit board, 4...controller, 11...scanning line, 12...signal line, 13...electrical element, PT1...first part, PT10...strip portion, PT11, PT12, PT13...curved portion, PT14...straight portion, IL1, IL2...island portion, r1, r2, r3...radius of curvature, W1, W2, W3, W4...line width, L1...straight distance, L2...total length.

Claims

1. an insulating substrate having elasticity; a plurality of wirings arranged on the insulating substrate; a plurality of electrical elements connected to the wiring, the insulating substrate has a plurality of island-shaped portions in which the electrical elements are located, and a plurality of strip-shaped portions in which the wiring is located and which connect adjacent island-shaped portions; each of the plurality of strip-shaped portions includes a meandering curved portion and a straight portion connecting the curved portion and the island-shaped portion; the curved portion includes a first curved portion, a second curved portion, and a third curved portion, the first curved portion is connected to the straight portion and curves away from the straight portion in both a first direction in which the straight portion extends and a second direction perpendicular to the first direction, the second curved portion is connected to the first curved portion and curves away from the straight portion in both directions; the third curved portion is connected to the second curved portion and curves away from the straight portion in the first direction and toward the straight portion in the second direction; The width of the second curved portion is smaller than the width of the third curved portion. electronic equipment.

2. The width of the first curved portion is smaller than the width of the second curved portion, The electronic device according to claim 1 , wherein a width of the straight portion is equal to a width of the first curved portion.

3. The electronic device according to claim 1 , wherein the first curved portion, the second curved portion, and the third curved portion have the same radius of curvature.

4. an insulating substrate having elasticity; a plurality of wirings arranged on the insulating substrate; a plurality of electrical elements connected to the wiring, the insulating substrate has a plurality of island-shaped portions in which the electrical elements are located, and a plurality of strip-shaped portions in which the wiring is located and which connect adjacent island-shaped portions; each of the plurality of strip-shaped portions includes a meandering curved portion and a straight portion connecting the curved portion and the island-shaped portion; the curved portion includes a first curved portion, a second curved portion, and a third curved portion, the first curved portion is connected to the straight portion and curves away from the straight portion in both a first direction in which the straight portion extends and a second direction perpendicular to the first direction, the second curved portion is connected to the first curved portion and curves away from the straight portion in both directions; the third curved portion is connected to the second curved portion and curves away from the straight portion in the first direction and toward the straight portion in the second direction; The radius of curvature of the second curved portion is larger than the radius of curvature of the third curved portion. electronic equipment.

5. The electronic device according to claim 4 , wherein a radius of curvature of the first curved portion is equal to a radius of curvature of the third curved portion.

6. 6. The electronic device according to claim 4, wherein a width of the first curved portion, a width of the second curved portion, a width of the third curved portion, and a width of the straight portion are equal to each other.

7. 7. The electronic device according to claim 1, wherein the insulating substrate is formed in a mesh shape.

8. 8. The electronic device according to claim 1, wherein the electrical element is a light-emitting element or a sensor.

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