Display device

Abstract

The display device disclosed in the present invention comprises a substrate, a display unit, a first wiring pad, a first recess, a second wiring pad and a side conductor. The substrate comprises a first surface, a side surface and a second surface opposite to the first surface. The display unit is located on the first surface and comprises a pixel unit. The first wiring pad is located in an edge region on the first surface and is electrically connected to the pixel unit. The first recess is located on the first outer surface of the first wiring pad. The second wiring pad is located in an edge region on the second surface at a position corresponding to the first wiring pad. The side conductor is provided from the first surface to the second surface via the side surface to connect the first wiring pad and the second wiring pad.

Description

Technical Field

[0001] The present disclosure relates to a display device. Background Art

[0002] Conventionally, for example, a display device described in Patent Document 1 is known.

[0003] Prior Art Literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2018-141944 Summary of the invention

[0006] The display device disclosed in the present invention comprises: a substrate having a first surface, a side surface, and a second surface on the side opposite to the first surface; a display portion, located on the first surface, and having a pixel portion; a first wiring pad, located in an edge region on one side of an edge on the first surface, and electrically connected to the pixel portion; a first recess, located on the first outer surface of the first wiring pad; a second wiring pad, located in an edge region on one side of the edge on the second surface, and located at a position corresponding to the first wiring pad; and a side conductor, which is provided from the first surface to the second surface via the side surface, and connects the first wiring pad and the second wiring pad.

[0007] The display device disclosed in the present invention comprises: a substrate having a first surface, a side surface, and a second surface opposite to the first surface; a display unit arranged on the first surface, having a plurality of gate signal lines, a plurality of source signal lines arranged to cross the plurality of gate signal lines, and a plurality of pixel units arranged corresponding to the intersections of the plurality of gate signal lines and the plurality of source signal lines; a power supply unit arranged on the second surface, generating a power supply voltage supplied to the plurality of pixel units; a plurality of first wiring pads arranged on the first surface; An end edge region on the first side of the first surface is connected to the plurality of pixel portions, and on the first outer surface of each first wiring pad on the side opposite to the surface opposite to the first surface, a plurality of first recesses are arranged at first adjacent intervals in a direction parallel to the first side; a plurality of second wiring pads are arranged on the second surface and connected to the power supply portion; and a plurality of first side conductors are arranged from the first surface to the second surface via the side surface to respectively connect the plurality of first wiring pads and the plurality of second wiring pads. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The objects, features and advantages of the present invention will become more apparent from the following detailed description and accompanying drawings.

[0009] Figure 1This is a diagram schematically showing circuit wiring and the like arranged on the first surface of the display device according to one embodiment of the present disclosure.

[0010] Figure 2 This is a diagram schematically showing circuit wiring and the like arranged on the second surface of the display device according to one embodiment of the present disclosure.

[0011] Figure 3 It is a plan view schematically showing an example of a main part of a display device according to an embodiment of the present disclosure.

[0012] Figure 4A is Figure 3 A cross-sectional view taken along the cutting line A1-A2.

[0013] Figure 4B is Figure 3 A cross-sectional view taken along the cutting line B1-B2.

[0014] Figure 5 It indicates Figure 4A 2 is a cross-sectional view of another example of the first wiring pad and the third wiring pad shown.

[0015] Figure 6 It is a plan view schematically showing another example of the main parts of the display device according to the embodiment of the present disclosure.

[0016] Fig. 7A It is a plan view schematically showing another example of the main parts of the display device according to the embodiment of the present disclosure.

[0017] Figure 7B It is a plan view schematically showing another example of the main parts of the display device according to the embodiment of the present disclosure.

[0018] Fig. 8A It is a plan view schematically showing another example of the main parts of the display device according to the embodiment of the present disclosure.

[0019] Figure 8B It is a plan view schematically showing another example of the main parts of the display device according to the embodiment of the present disclosure.

[0020] Fig. 9 It is a plan view schematically showing another example of the main parts of the display device according to the embodiment of the present disclosure.

[0021] Fig.10 It is a plan view schematically showing another example of the main parts of the display device according to the embodiment of the present disclosure.

[0022] Fig.11AIt is a plan view schematically showing another example of the main parts of the display device according to the embodiment of the present disclosure.

[0023] Fig. 11B It is a plan view schematically showing another example of the main parts of the display device according to the embodiment of the present disclosure.

[0024] Fig. 12A It is a plan view schematically showing another example of the main parts of the display device according to the embodiment of the present disclosure.

[0025] Fig. 12B It is a plan view schematically showing another example of the main parts of the display device according to the embodiment of the present disclosure.

[0026] Fig.13A It is a plan view schematically showing another example of the main parts of the display device according to the embodiment of the present disclosure.

[0027] Fig. 13B It is a plan view schematically showing another example of the main parts of the display device according to the embodiment of the present disclosure.

[0028] Fig.14A is Fig. 12A Cross-sectional view taken along the cutting line C1-C2.

[0029] Fig. 14B The display device according to another embodiment of the present disclosure is equivalent to Fig.14A Cross-sectional view of a cross-sectional view of a cross-sectional view.

[0030] Fig.15 It is a plan view schematically showing another example of the main parts of the display device according to the embodiment of the present disclosure. DETAILED DESCRIPTION

[0031] The display device involved in the embodiment of the present disclosure is described as a basic structure. In the past, various display devices have been proposed, in which a display unit is arranged on the first main surface of a substrate having a first main surface and a second main surface on the opposite side thereof, and peripheral circuits such as a power supply circuit and a drive circuit are arranged on the second main surface. In the display device described in Patent Document 1, a first wiring pad located on the first main surface and connected to the display unit and a second wiring pad located on the second main surface and connected to the peripheral circuit are connected using a side conductor formed from the first main surface to the second main surface via the side surface of the substrate. In such a display device, if the side conductor is peeled off from the first wiring pad or the second wiring pad, sometimes line defects, poor drawing, and other display quality reductions will occur in the display image of the display device. It is sought to suppress the peeling of the side conductor from the first wiring pad and the second wiring pad, so as to improve the display quality of the display device.

[0032] The following drawings are used to illustrate the display device involved in the embodiment of the present disclosure. In addition, each figure referenced below shows the main components of the display device involved in the embodiment of the present disclosure. Therefore, the display device involved in the embodiment of the present disclosure may also have well-known structures such as a circuit substrate, wiring conductors, control IC, LSI, etc. that are not shown in the figure.

[0033] Figure 1 is a diagram schematically showing circuit wiring and the like arranged on the first surface of a display device according to an embodiment of the present disclosure, Figure 2 is a diagram schematically showing circuit wiring and the like arranged on the second surface of a display device according to an embodiment of the present disclosure, Figure 3 FIG. 1 is a plan view schematically showing an example of a main part of a display device according to an embodiment of the present disclosure. Figure 3 In order to facilitate illustration, elements other than the light-emitting element of the pixel portion and the electrode pad, the first wiring pad, and the second wiring pad are omitted. Figure 4A is Figure 3 The cross-sectional view of the cutting plane line A1-A2, Figure 4B is Figure 3 The cross-sectional view of the cutting plane line B1-B2, Figure 5 It indicates Figure 4A 2 is a cross-sectional view of another example of the first wiring pad and the third wiring pad shown. Figure 6~1 3 and 15 are plan views schematically showing other examples of the main parts of the display device according to the embodiment of the present disclosure. Figures 6 to 9 , 12, 13, and 15 schematically show the structure of the first wiring pad and the third wiring pad arranged on the first surface, Fig.10 11 schematically shows the structure of the second wiring pad and the fourth wiring pad arranged on the second surface. Fig.14A is Fig. 12A The cross-sectional view of the cutting plane line C1-C2, Fig. 14B The display device according to another embodiment of the present disclosure is equivalent to Fig.14A Cross-sectional view of a cross-sectional view of a cross-sectional view.

[0034] The display device 1 of the present embodiment includes a substrate 2 , a display unit 3 , a power supply circuit 7 , a plurality of first wiring pads 8 , a plurality of second wiring pads 9 , and a plurality of first side conductors 10 .

[0035] The display device 1 of this embodiment is as follows Figure 1 , Figure 4A as well as Fig. 12A As shown, the structure comprises the following elements: a substrate 2 having a first surface 2a, a side surface 2c and a second surface 2b on the side opposite to the first surface 2a; a display portion 3, which is located on the first surface 2a and has a pixel portion 6; a first wiring pad 8, which is located in an edge region on one side of one edge (the first edge 2aa) on the first surface 2a and is electrically connected to the pixel portion 6; a first recess 8b, which is located on the first outer surface 8a of the first wiring pad 8; a second wiring pad 9, which is located in an edge region on one side of the first edge 2aa on the second surface 2b and is located at a position corresponding to the first wiring pad 8; and a first side conductor 10, which is provided from the first surface 2a to the second surface 2b via the side surface 2c and serves as a side conductor connecting the first wiring pad 8 and the second wiring pad 9.

[0036] The display device 1 has the following effects by the above-mentioned structure. Since the first outer surface 8a of the first wiring pad 8 connected to the first side conductor 10 has the first recess 8b, the first side conductor 10 is firmly connected to the first wiring pad 8 by the anchoring effect. As a result, the first side conductor 10 can be prevented from peeling off from the first wiring pad 8, so that the display quality of the display device 1 can be improved. In addition, the portion other than the first recess 8b in the first outer surface 8a of the first wiring pad 8 becomes a current path I1 (with the first recess 8b as the first recess 8b) through which current easily flows. Fig. 12A Furthermore, when the first side conductor 10 entering the first recess 8b has a relatively large volume and a relatively thick thickness (for example, about 0.1 μm to 5 μm), the first side conductor 10 in the first recess 8b also becomes a current path I2 through which current easily flows (indicated by a dotted arrow). Fig. 12A This is because the first side conductor 10 is less likely to be interrupted at the step of the first recess 8b. As a result, the connection resistance (contact resistance) between the first wiring pad 8 and the first connection portion 10a of the first side conductor 10 can be suppressed from increasing.

[0037] In other words, the first concave portion 8b is a pit or depression, and may have an area of ​​about 5% to 30% of the area of ​​the first outer surface 8a of the first wiring pad 8 when viewed from above. That is, the first concave portion 8b is different from the concave portion in the fine concave-convex when the first outer surface 8a of the first wiring pad 8 is roughened. In the case of a structure in which the first outer surface 8a of the first wiring pad 8 is roughened, a method of chemically or mechanically roughening the first outer surface 8a by etching, sandblasting, etc. is adopted. However, these methods require an etching device, a sandblasting device, etc., and require a protective member such as a protective layer to protect the roughened target area, so they take time and effort, and the manufacturing cost is high. In addition, there is a problem that it is difficult to form fine concave-convex with uniform surface roughness on the first outer surface 8a of the first wiring pad 8. The display device 1 of this embodiment can form the first concave portion 8b at a low cost by a thin film formation method when forming the first wiring pad 8. Furthermore, even if there are a plurality of first wiring pads 8 , the first recessed portion 8 b having a uniform shape and depth can be formed in each of the first wiring pads 8 .

[0038] The shape of the first recess 8b when viewed from above may be circular, rectangular, rectangular with rounded corners, oval, elliptical, trapezoidal, groove (belt), etc., or other shapes. When the first recess 8b is groove-shaped, it may be a groove extending in a direction perpendicular to the first side 2aa. In this case, a current path I1 of sufficient size can be ensured.

[0039] The second wiring pad 9 has a second recess 9b located on the second outer surface 9a, and the first side conductor 10 may be a structure covering the first outer surface 8a and the second outer surface 9a. In this case, a signal can be supplied to the display unit 3 located on the first surface 2a of the substrate 2 from the side of the second surface 2b via the first side conductor 10 while suppressing a voltage drop. A signal supply unit that supplies a signal to the display unit 3 may exist on one side of the second surface 2b. The signal supply unit may be a power supply unit that supplies a power supply voltage, or a drive unit that supplies a drive signal such as a gate signal and a source signal.

[0040] like Fig. 12AAs shown in the figure, when there is a first recess 8b on the first outer surface 8a, the maximum width wa of the first recess 8b in the direction parallel to the first side 2aa can be less than 1 / 2 of the maximum width wb of the first outer surface 8a in the direction parallel to the first side 2aa. In this case, a current path I1 of sufficient size can be ensured. In addition, wa can be more than 1 / 10 of wb. If wa exceeds 1 / 2 of wb, the current path I1 tends to become smaller. When wa is less than 1 / 10 of wb, there is a tendency that the anchoring effect of the first recess 8b on the first side conductor 10 tends to become smaller, the connectivity of the first side conductor 10 to the first wiring pad 8 decreases, and the current path I2 tends to become smaller. Fig. 12A The structure shown can also be applied to the second recess 9b.

[0041] In addition, if Fig. 12B As shown, when there are a plurality of first recesses 8b on the first outer surface 8a, the sum of the maximum widths wa1 and wa2 of each first recess 8b in the direction parallel to the first side 2aa can be less than 1 / 2 of the maximum width wb of the first outer surface 8a in the direction parallel to the first side 2aa. In this case, a current path I1 of sufficient size can be ensured. In addition, the sum of wa1 and wa2 can be more than 1 / 10 of wb. If the sum of wa1 and wa2 exceeds 1 / 2 of wb, the current path I1 tends to become smaller. When the sum of wa1 and wa2 is less than 1 / 10 of wb, there is a tendency that the anchoring effect of the first recess 8b on the first side conductor 10 tends to become smaller, the connectivity of the first side conductor 10 to the first wiring pad 8 tends to decrease, and further, the current path I2 tends to become smaller. Fig. 12B The structure shown can also be applied to the second recess 9b.

[0042] like Fig.13A As shown in FIG. 1 , the first side conductor 10 may cover more than 1 / 2 of the area of ​​the first outer surface 8a and more than 1 / 2 of the area of ​​the first recess 8b. In this case, the amount of the first side conductor 10 can be saved, and the increase in the connection resistance at the connection portion between the first wiring pad 8 and the first side conductor 10 can be suppressed, and the anchoring effect of the first recess 8b on the first side conductor 10 can be ensured. In addition, the first side conductor 10 can be suppressed from contacting with other electrodes, wirings, etc. to generate an unnecessary short circuit. Fig.13A The structure can also be applied to the second recess 9b.

[0043] like Fig. 13BAs shown in FIG. 1 , the first side conductor 10 may cover an area exceeding 1 / 2 of the area of ​​the first outer surface 8a and the entire first recess 8b. In this case, the amount of the first side conductor 10 can be saved to some extent, and the increase in the connection resistance at the connection portion between the first wiring pad 8 and the first side conductor 10 can be further suppressed, and the anchoring effect of the first recess 8b on the first side conductor 10 can be further ensured. In addition, the first side conductor 10 can be suppressed from contacting with other electrodes, wirings, etc. to generate an unnecessary short circuit. Fig. 13B The structure can also be applied to the second recess 9b.

[0044] like Fig.14A As shown in the figure, the first wiring pad 8 is a multilayer structure in which a plurality of metal layers (including alloy layers) are stacked, and the first recess 8b may be a structure in which the maximum width gradually decreases as it goes in the depth direction. In this case, the number of steps existing in the first recess 8b increases, and the number of places where the first side conductor 10 is hooked in the first recess 8b increases. As a result, the anchoring effect of the first recess 8b on the first side conductor 10 is enhanced. In addition, Fig.14A In the figure, 2e represents an insulating layer.

[0045] like Fig. 14B As shown, in Fig.14A In the structure, the number of steps on the side of the first side 2aa in the first recess 8b may be greater than the number of steps on the side opposite to the first side 2aa in the first recess 8b. In this case, if the first side conductor 10 is formed by applying and firing the conductive paste, the first side conductor 10 shrinks in volume during the process of firing the conductive paste and slightly retreats to the side of the first side 2aa. At this time, the first side conductor 10 is easy to hook on the step on the side of the first side 2aa in the first recess 8b, and is difficult to hook on the step on the side opposite to the first side 2aa in the first recess 8b. Therefore, the anchoring effect of the first recess 8b on the first side conductor 10 can be ensured or improved.

[0046] like Fig.15 As shown in FIG. 1 , the first recess 8b may be configured such that the width of the first side 2aa on one side in a direction parallel to the first side 2aa is smaller than the width of the first side 2aa on the opposite side to the first side 2aa. In this case, if the first side conductor 10 is formed by applying and firing the conductive paste, the first side conductor 10 shrinks in volume and slightly retreats to the first side 2aa during the firing process of the conductive paste. At this time, in the first recess 8b, the conductive paste can be suppressed from retreating to the first side 2aa. As a result, the first side conductor 10 can be suppressed from being easily peeled off from the step on the opposite side to the first side 2aa in the first recess 8b. Fig.15The first concave portion 8b is shown as a trapezoidal structure when viewed from above, but it may also be a convex shape, a triangular shape, a triangular shape with rounded corners, or the like. Fig. 12B Similarly, one first wiring pad 8 has a plurality of first recessed portions 8 b.

[0047] The substrate 2 is, for example, a transparent or opaque glass substrate, a plastic substrate, a ceramic substrate, etc. The substrate 2 has a first surface 2a, a second surface 2b on the side opposite to the first surface 2a, and a third surface (hereinafter also referred to as a side surface) 2c connecting the first surface 2a and the second surface 2b. The shape of the substrate 2 can be a triangular plate, a rectangular plate, a hexagonal plate, etc., or can be other shapes. In the case where the shape of the substrate 2 is a triangular plate, a rectangular plate, a hexagonal plate, etc., it is easy to tile a plurality of display devices 1 to produce a composite and large display device (hereinafter also referred to as a multi-display). In the present embodiment, for example Figure 1 , 2 As shown, the substrate 2 has a rectangular plate shape, and the first surface 2a has a first side 2aa and a second side 2ab connected to the first side 2aa.

[0048] The display unit 3 is arranged on the first surface 2a of the substrate 2. The display unit 3 has a plurality of gate signal lines 4, a plurality of source signal lines 5, and a plurality of pixel units 6. The plurality of gate signal lines 4 extend in a given direction ( Figure 1 The plurality of source signal lines 5 are arranged to intersect the plurality of gate signal lines 4. The plurality of pixel portions 6 are arranged corresponding to the intersections of the plurality of gate signal lines 4 and the plurality of source signal lines 5. The plurality of pixel portions 6 are arranged, for example Figure 1 As shown, they are arranged in a matrix at a given pixel pitch.

[0049] Each of the plurality of pixel units 6 includes a light emitting element 61 and an electrode pad 62 .

[0050] The light emitting element 61 is, for example, a self-luminous element such as a light emitting diode (LED) element, an organic electroluminescent element, or a semiconductor laser element. In the present embodiment, an LED element is used as the light emitting element 61. The light emitting element 61 may be a micro LED element. When the light emitting element 61 is a micro LED element, the light emitting element 61 may have a rectangular shape when viewed from above, with a side length of about 1 μm or more and about 100 μm or about 3 μm or more and about 10 μm or less, when arranged on the first surface 2a.

[0051] The light emitting element 61 has an anode terminal and a cathode terminal, and the electrode pad 62 has an anode pad 62a and a cathode pad 62b. The anode terminal and the cathode terminal of the light emitting element 61 are electrically connected to the anode pad 62a and the cathode pad 62b respectively via a conductive bonding material such as a conductive adhesive or solder.

[0052] Each pixel unit 6 may include a plurality of light-emitting elements 61, a plurality of anode pads 62a, and a cathode pad 62b. A plurality of anode terminals of the plurality of light-emitting elements 61 are electrically connected to the plurality of anode pads 62a, and a plurality of cathode terminals of the plurality of light-emitting elements 61 are electrically connected to the plurality of cathode pads 62b. The plurality of light-emitting elements 61 may be a light-emitting element 61R that emits red light, a light-emitting element 61G that emits green light, and a light-emitting element 61B that emits blue light. In this case, each pixel unit 6 can perform a color grayscale display. Each pixel unit 6 may also include a light-emitting element that emits orange light, red-orange light, red-purple light, or purple light instead of the light-emitting element 61R that emits red light. In addition, each pixel unit 6 may also include a light-emitting element that emits yellow-green light instead of the light-emitting element 61G that emits green light.

[0053] The power supply circuit 7 as a power supply unit is, for example, Figure 2 As shown, the power supply circuit 7 is arranged on the second surface 2b. The power supply circuit 7 generates a first power supply voltage VDD and a second power supply voltage VSS supplied to the plurality of pixel units 6. The power supply circuit 7 includes: a VDD terminal for outputting the first power supply voltage VDD; and a VSS terminal for outputting the second power supply voltage VSS. The first power supply voltage VDD is, for example, an anode voltage of about 10V to 15V. The second power supply voltage VSS is a voltage lower than the first power supply voltage VDD, for example, a cathode voltage of about 0V to 3V. The power supply circuit 7 may include, for example, a flexible circuit board (Flexible Circuit Board: FPC). The power supply unit may be a circuit module having semiconductor elements such as IC and LSI for power supply voltage control. Furthermore, the power supply unit may include: a power supply circuit 7; and a light control element including an IC chip for generating control signals for controlling light emission, non-light emission, light emission intensity, etc. of the light emitting element 61.

[0054] For example, the plurality of first wiring pads 8 Figure 1As shown in FIG. 1 , the edge region is arranged on the side of the first side 2aa on the first surface 2a. The edge region is a side region along the first side 2aa, and is a region having a width of about 10 μm to 500 μm from the first side 2aa on the first surface 2a to the center side of the first surface 2a, but is not limited to the value of this width. The plurality of first wiring pads 8 include a plurality of first pads 81 and a plurality of second pads 82. The first pad 81 is a wiring pad for supplying a first power supply voltage VDD to the plurality of pixel units 6, and the second pad 82 is a wiring pad for supplying a second power supply voltage VSS to the plurality of pixel units 6. The first wiring pad 8 may be a rectangular shape with a length of about 50 μm to 500 μm on one side, or a rectangular shape with a length of about 70 μm to 300 μm, but the length of one side is not limited to these values, and the shape may be various shapes such as a polygonal shape such as a 5-sided shape, a trapezoidal shape, a circular shape, an elliptical shape, etc. Hereinafter, the same structure can be adopted for the wiring pads.

[0055] Each of the plurality of first wiring pads 8 has a first outer surface 8a on the side opposite to the surface facing the first surface 2a. Figure 3 As shown in FIG. 1 , a plurality of first recesses 8b are arranged in a direction parallel to the first side 2aa with first adjacent intervals 8bk spaced apart. Thus, the first adjacent intervals 8bk in the first wiring pad 8 become current paths through which current easily flows ( Figure 3 The first adjacent spacing 8bk in the first wiring pad 8 is a portion where current easily flows because the creepage distance of the first wiring pad 8 including the conductor layer is short and the thickness of the first wiring pad 8 is constant. In addition, the first adjacent spacing 8bk is the spacing between the adjacent first recesses 8b in the plurality of first recesses 8b.

[0056] The first adjacent interval 8bk of the display device 1 of the present embodiment may be larger than the maximum width of the first recess 8b in the direction parallel to the first side 2aa. In this case, in the first wiring pad 8, since the width of the first adjacent interval 8bk, which is a current path through which current easily flows, is larger than the maximum width of the first recess 8b, the increase in resistance of the first wiring pad 8 can be further suppressed. In addition, when the width of the first recess 8b in the direction parallel to the first side 2aa is constant, the maximum width can be specified as only the width. When the maximum width of the first recess 8b in the direction parallel to the first side 2aa is w1 and the first adjacent interval 8bk is w2, w2 can be set to be more than 1 times w1 and less than about 15 times. In addition, w1 can be about 0.1μm to 30μm, or about 0.3μm to 10μm. When the metal layer 83 is processed by photolithography or the like to form the first recessed portion 8b, the depth of the first recessed portion 8b may be about 100 nm to 1000 nm, and when the insulating layer 25 is processed by photolithography or the like to form the first recessed portion 8b, the depth of the first recessed portion 8b may be about 1 μm to 5 μm. The same structure can be adopted for the recessed portion provided in the wiring pad.

[0057] In addition, the metal layer 83 ( Figure 4A , 4B ) and / or insulating layer 25 ( Figure 5 (described in the specification) a primary recess is formed in advance by photolithography, dry etching, etc., and each layer is stacked on the primary recess to form the first recess 8b. Hereinafter, the recess provided in the wiring pad can also be formed by the same method. The insulating layer 25 can include, for example, inorganic insulating materials such as SiO2 and Si3N4, organic insulating materials such as acrylic resin and polycarbonate resin, etc.

[0058] The display device 1 is, for example, Figure 1 As shown, the first lead wiring 11a and the second lead wiring 11b are provided. The first lead wiring 11a and the second lead wiring 11b are located on the first surface 2a. The first lead wiring 11a and the second lead wiring 11b include, for example, Mo / Al / Mo, MoNd / AlNd / MoNd, etc. Here, "Mo / Al / Mo" means a stacked structure in which an Al layer is stacked on a Mo layer, and a Mo layer is stacked on an Al layer. The same is true for the others. The first lead wiring 11a connects the anode terminal of the light emitting element 61 to the plurality of first pads 81. The second lead wiring 11b connects the cathode terminal of the light emitting element 61 to the plurality of second pads 82.

[0059] The first routing wiring 11a and the second routing wiring 11b may be planar wiring patterns. In this case, the first routing wiring 11a and the second routing wiring 11b are electrically insulated from each other by an insulating layer (not shown) disposed therebetween. The anode pad 62a of the electrode pad 62 may also be formed as a part of the first routing wiring 11a.

[0060] The plurality of second wiring pads 9 are located on the second surface 2b. The plurality of second wiring pads 9 may be, for example, Figure 2 As shown in FIG. 1 , the edge region is arranged on the side of the first side 2aa. The edge region may have the same structure as the edge region described above. The plurality of second wiring pads 9 include a plurality of third pads 91 and a plurality of fourth pads 92. The third pads 91 are wiring pads for supplying the first power supply voltage VDD to the plurality of pixel units 6, and the fourth pads 92 are wiring pads for supplying the second power supply voltage VSS to the plurality of pixel units 6.

[0061] The display device 1 may have a structure in which the number of the plurality of first pads 81 is equal to the number of the plurality of third pads 91, and the number of the plurality of second pads 82 is equal to the number of the plurality of fourth pads 92. The plurality of first pads 81 and the plurality of third pads 91 may overlap when viewed from above, that is, when viewed from a direction perpendicular to the first surface 2a. The plurality of second pads 82 and the plurality of fourth pads 92 may overlap when viewed from above.

[0062] The display device 1 has a third routing wiring 12. The third routing wiring 12 is located on the second surface 2b. The third routing wiring 12 includes, for example, Mo / Al / Mo, MoNd / AlNd / MoNd, Ag, etc. Figure 2 As shown, the third routing wiring 12 connects the VDD terminal of the power supply circuit 7 and the plurality of third pads 91 , and connects the VSS terminal of the power supply circuit 7 and the plurality of fourth pads 92 .

[0063] The plurality of first side conductors 10 are arranged from the first surface 2a to the second surface 2b via the third surface 2c. Figure 4A , 4B As shown in FIG. 5 , the plurality of first side conductors 10 are arranged from the first surface 2a to the third surface 2c and the second surface 2b. The plurality of first side conductors 10 connect the plurality of first wiring pads 8 and the plurality of second wiring pads 9, respectively. The plurality of first side conductors 10 are, for example, Figure 1 , 2 As shown, the plurality of first pads 81 and the plurality of third pads 91 are connected to each other, and the plurality of second pads 82 and the plurality of fourth pads 92 are connected to each other.

[0064] The display device 1 may be a structure having a plurality of through conductors that penetrate from the first surface 2a to the second surface 2b to connect the plurality of first wiring pads and the plurality of second wiring pads, respectively, instead of the plurality of first side conductors 10. In addition, the display device 1 may be a structure having a plurality of first side conductors 10 and a plurality of through conductors. The display device 1 of this embodiment may be a structure having at least a plurality of first side conductors 10.

[0065] The display device 1 has a gate wiring which is arranged from the first surface 2a to the second surface 2b and connects a plurality of gate signal lines 4 and control elements of a power supply circuit 7. The gate wiring is, for example, Figure 1 , 2 As shown, a fifth wiring pad 18, a sixth wiring pad 19, a first gate wiring 20, a second gate wiring 21, and a third gate wiring 22 are provided.

[0066] The fifth wiring pad 18 is, for example, Figure 1 As shown in FIG. 1 , the sixth wiring pad 19 is disposed in the edge region on the first side 2aa side of the first surface 2a. Figure 2 As shown in FIG. 1 , the fifth wiring pad 18 and the sixth wiring pad 19 may overlap each other in a plan view. The first gate wiring 20 may be, for example, Figure 1 As shown in FIG. 1 , the second gate wiring 21 is disposed on the first surface 2a to connect the plurality of gate signal lines 4 and the fifth wiring pad 18. Figure 2 As shown in FIG. 1 , the third gate wiring 22 is disposed on the second surface 2b to connect the control element of the power supply circuit 7 and the sixth wiring pad 19. Figure 1 , 2 As shown, the fifth wiring pad 18 and the sixth wiring pad 19 are connected from the first surface 2a to the third surface 2c and the second surface 2b.

[0067] Next, the detailed structures of the pixel portion 6 , the first wiring pad 8 , the second wiring pad 9 , and the first side-surface conductor 10 will be described.

[0068] In this embodiment, for example Figure 3 As shown in FIG. 1 , each pixel portion 6 includes a light emitting element 61R that emits red light, a light emitting element 61G that emits green light, and a light emitting element 61B that emits blue light. In addition, the electrode pad 62 of each pixel portion 6 includes three anode pads 62a and a cathode pad 62b. The light emitting elements 61R, 61G, and 61B may be, for example, Figure 3As shown in FIG. 1 , the pixels 6 are arranged in an L-shape when viewed from above. As a result, the area of ​​the pixel unit 6 when viewed from above becomes smaller, and the shape of the pixel unit 6 when viewed from above can be made compact and square, etc. Furthermore, the pixel density of the display device 1 can be improved, and high-quality images can be displayed.

[0069] The first wiring pad 8 and the second wiring pad 9 include a conductive material. The first wiring pad 8 and the second wiring pad 9 may include a single metal layer or may be formed by stacking a plurality of metal layers. The first wiring pad 8 and the second wiring pad 9 may include, for example, Al, Al / Ti, Ti / Al / Ti, Mo, Mo / Al / Mo, MoNd / AlNd / MoNd, Cu, Cr, Ni, Ag, etc. Figure 4A , 4B , an example is shown in which the first wiring pad 8 includes two metal layers 83 and 84 stacked on each other and arranged on the insulating layer 23 formed on the first surface 2a. The insulating layer 23 may include, for example, a polymer material such as SiO2, Si3N4, or acrylic resin. Figure 4A , 4B , an example is shown in which the second wiring pad 9 includes a single metal layer 93 and is arranged on the second surface 2b.

[0070] When the first wiring pad 8 is formed by laminating two metal layers 83 and 84, for example, Figure 4A , 4B As shown in FIG. 5 , the insulating layer 24 is disposed in a portion between the metal layers 83 and 84. In addition, the inner side ( Figure 4A Insulating layers 25, 26, and 27 are arranged at the end portion (right side in the figure). As a result, short circuit between the first wiring pad 8 and the wiring conductor arranged on the inner side of the first surface 2a can be suppressed. The insulating layers 25, 26, and 27 include, for example, polymer materials such as SiO2, Si3N4, and acrylic resin. The first outer surface 8a of the first wiring pad 8 can be covered with a transparent conductive layer 28 including ITO (Indium Tin Oxide, indium tin oxide), IZO (Indium Zinc Oxide, indium zinc oxide), etc. The surface of the second wiring pad 9 can be covered with a transparent conductive layer including ITO, IZO, etc.

[0071] In addition, for example Figure 5 As shown in FIG. 1 , the insulating layer 25 may be disposed toward the outer side of the first surface 2a ( Figure 5 The left side in FIG. 25 extends and is located between the metal layer 83 and the insulating layer 23. In addition, a concavoconvex portion of the insulating layer 25 located between the metal layer 83 and the insulating layer 23 may be formed.

[0072] The first side conductor 10 is, for example, Figure 4A , 4B 5, the first wiring pad 8 and the second wiring pad 9 are connected from the first surface 2a to the third surface 2c and the second surface 2b. After applying a conductive paste containing conductive particles such as Ag, Cu, Al, stainless steel, etc., an uncured resin component, an alcohol solvent, and water, etc. to the desired positions from the first surface 2a to the third surface 2c and the second surface 2b, the first side conductor 10 can be formed by a heating method, a photocuring method that hardens by irradiation with light such as ultraviolet rays, a photocuring heating method, etc. The side conductor is formed by plating, evaporation, and a thin film forming method such as CVD (Chemical Vapor Deposition). In addition, a groove can be pre-formed at the position of the first side conductor 10 in the third surface 2c. As a result, the conductive paste that becomes the first side conductor 10 becomes easy to be arranged at the desired position in the third surface 2c.

[0073] In the display device 1 of this embodiment, for example Figure 3 As shown, a plurality of first recesses 8b are formed on the first outer surface 8a of the first wiring pad 8. For this reason, by the first side conductor 10 entering at least one of the plurality of first recesses 8b, or by the first side conductor 10 entering at least a portion of each of the plurality of first recesses 8b, the contact area with the first wiring pad 8 is further increased compared to a case where the plurality of first recesses 8b are not formed on the first outer surface 8a. Furthermore, by the first side conductor 10 entering at least one of the first recesses 8b, or by the first side conductor 10 entering at least a portion of each of the plurality of first recesses 8b, an anchoring effect is generated between the first side conductor 10 and the first wiring pad 8. As a result, since the first side conductor 10 becomes difficult to peel off from the first wiring pad 8, the display quality of the display device can be improved. The opening shape of each of the plurality of first recesses 8b can be, for example, a circular shape, a rectangular shape with rounded corners, an oval shape, or other shapes. Figure 3 In the structure of the present invention, there may be a protective insulating layer (overcoat) 10c covering the first side conductor 10. In this case, the protective insulating layer 10c enters the portion of the plurality of first recesses 8b where the first side conductor 10 does not enter, and an anchoring effect is also generated between the protective insulating layer 10c and the first wiring pad 8. As a result, the first side conductor 10 becomes more difficult to be peeled off from the first wiring pad 8. The protective insulating layer 10c may include acrylic resin, polycarbonate resin, or the like.

[0074] The first wiring pad 8 may be, for example, Figure 6As shown in FIG. 1 , the entire first outer surface 8a is covered by the first side conductor 10 connected to the first wiring pad 8. In this case, since the first side conductor 10 enters all of the first recesses 8b among the plurality of first recesses 8b, the contact area between the first side conductor 10 and the first wiring pad 8 can be further increased, and the anchor effect generated between the first side conductor 10 and the first wiring pad 8 can be enhanced. As a result, the first side conductor 10 becomes more difficult to be peeled off from the first wiring pad 8, and thus the display quality of the display device can be further improved.

[0075] The plurality of first recesses 8b may be respectively formed as follows, for example Fig. 7A , 7B As shown in FIG. 1 , the groove-shaped portion is elongated in the first direction D1 from the first side 2aa side to the center side of the first surface 2a in a plan view. In this case, since the contact area between the first side conductor 10 and the first wiring pad 8 can be further increased, the contact resistance between the first side conductor 10 and the first wiring pad 8 can be reduced. In addition, since the width of the current path in the first wiring pad 8 is difficult to change, it also has the effect of maintaining the function of easy current flow. The first recessed portion 8b including a plurality of groove-shaped portions can be arranged in parallel. In this case, since the width of the current path does not change, the function of easy current flow can be maintained. The length of the first recessed portion 8b including the groove-shaped portion in the long side direction can be slightly shorter (about 10% to 30% shorter) than the length of one side of the first wiring pad 8 (about 50μm to 500μm or about 70μm to 300μm).

[0076] The first recess 8b including a plurality of groove-shaped portions may have at least a portion of the recesses arranged in parallel. In other words, the first recess 8b including a plurality of groove-shaped portions may have a portion of the recesses arranged non-parallel, or all the recesses arranged in parallel. For example, the recess located in the central portion of the first recess 8b including a plurality of groove-shaped portions may be parallel to the direction orthogonal to the first side 2aa, the recess located at the two ends may be non-parallel to the recess located in the central portion, and the first adjacent interval 8bk may become smaller as the first side 2aa is approached. In this case, the first side conductor 10 formed by applying and firing the conductive paste can make the long side direction of the first recess 8b including a plurality of groove-shaped portions roughly consistent with the direction of volume shrinkage when viewed from above on the first wiring pad 8 during firing. As a result, the first side conductor 10 can be prevented from deteriorating the adhesion between the first side conductor 10 and the first wiring pad 8 and from peeling off the first side conductor 10 from the first wiring pad 8. The inclination angle of the concave portion located in the center and the concave portions located at both ends of the first concave portion 8b including the plurality of groove-like portions may be set to be greater than 0° and approximately 30° or less, or may be set to be greater than 5° and approximately 20° or less.

[0077] In addition, you can Fig. 7A , 7B As shown in FIG. 1 , the first direction D1 is a direction orthogonal to the first side 2aa, and each of the plurality of first recesses 8b may be a slot-shaped portion that is elongated in the first direction D1 when viewed from above. In this case, the power supply current supplied from the power supply circuit 7 flows through the first connecting portion 10a located on the first outer surface 8a of the first side conductor 10 roughly along the first surface 2a and in a direction orthogonal to the first side 2aa. Therefore, in the case where the first recess 8b is a slot-shaped portion that is elongated in the first direction D1, the first connecting portion 10a enters the first recess 8b, thereby increasing the cross-sectional area of ​​the first connecting portion 10a in the direction in which the power supply current flows, and reducing the resistance of the first connecting portion 10a. That is, the first connecting portion 10a in the first recess 8b can become a good current path. As a result, the heat generation in the first connecting portion 10a is suppressed, and the thermal stress generated at the interface between the first side conductor 10 and the first wiring pad 8 can be reduced. As a result, since the first side conductor 10 becomes more difficult to be peeled off from the first wiring pad 8, the display quality of the display device can be further improved. Furthermore, the first direction D1 is a direction perpendicular to the first side 2aa, and the first recessed portion 8b including a plurality of groove-shaped portions can be arranged in parallel. In this case, since the width of the current path in the first wiring pad 8 does not change, the function of making it easier for current to flow can be maintained.

[0078] Each of the plurality of first recesses 8b may extend over substantially the entire first outer surface 8a in the first direction D1. In this case, the resistance of the first connecting portion 10a can be effectively reduced. Thus, the heat generation in the first connecting portion 10a can be effectively suppressed, and the thermal stress generated at the interface between the first side conductor 10 and the first wiring pad 8 can be effectively suppressed. As a result, since the first side conductor 10 becomes more difficult to be peeled off from the first wiring pad 8, the display quality of the display device can be further improved.

[0079] like Figure 7B As shown in FIG. 1 , at least a portion of the plurality of first recesses 8b may have an opening at the end portion on the first side 2aa side. In this case, the conductive paste that becomes the first side conductor 10 can easily enter the first recess 8b from the opening portion of the first recess 8b. Of course, all of the plurality of first recesses 8b may have an opening at the end portion on the first side 2aa side. In addition, regarding the third recess 14b described later, it is also possible to adopt Figure 7B The structure shown.

[0080] The plurality of first recesses 8b may be, for example, Fig. 8A , 8BAs shown in FIG. 9 , in a plan view, the first direction D1 and the second direction D2 intersecting the first direction D1 are arranged in a matrix. The angle between the first direction D1 and the second direction D2 in a plan view can be, for example, Fig. 8A , 8B As shown, it is 90°, for example, Fig. 9 As shown in the figure, it is larger than 0° and smaller than 90°. The plurality of first recesses 8b may be arranged in a matrix of a plurality of rows and a plurality of columns.

[0081] You can also Figure 8B As shown in FIG. 1 , the end of the first side 2aa side of the recessed portion closest to the first side 2aa among the plurality of first recessed portions 8b becomes an opening. Figure 7B In addition, regarding the third recess 14b described later, it is also possible to adopt Figure 8B The structure shown.

[0082] When a plurality of first recesses 8b are arranged in a matrix, more first recesses 8b can be formed more efficiently on the first outer surface 8a than when a plurality of first recesses 8b are not arranged in a matrix. For this reason, the contact area between the first side conductor 10 and the first wiring pad 8 can be further increased, and the anchoring effect generated between the first side conductor 10 and the first wiring pad 8 can be improved. Furthermore, the cross-sectional area of ​​the first connecting portion 10a in the direction of flow of the power supply current can be increased, and the resistance of the first connecting portion 10a can be reduced. As a result, since the heat generation in the first connecting portion 10a can be effectively suppressed, and the thermal stress generated at the interface between the first connecting portion 10a and the first wiring pad 8 can be effectively suppressed, the first side conductor 10 becomes more difficult to be peeled off from the first wiring pad 8. Furthermore, the display quality of the display device can be further improved.

[0083] In addition, for example Fig. 9 As shown in FIG. 1 , when the angle between the first direction D1 and the second direction D2 is larger than 0° and smaller than 90° in a plan view, that is, when the plurality of first recesses 8b are arranged in a staggered manner in a plan view, the dispersion of the arrangement of the plurality of first recesses 8b in the first wiring pad 8 can be improved (set to a more uniformly dispersed arrangement as a whole). As a result, local heat generation in the first side conductor 10 can be suppressed, and the possibility of large thermal stress being locally generated at the interface between the first wiring pad 8 and the first side conductor 10 can be reduced. As a result, since the first side conductor 10 becomes difficult to peel off from the first wiring pad 8, the display quality of the display device can be further improved.

[0084] Furthermore, when the plurality of first recesses 8b are arranged in a staggered manner when viewed from above, the plurality of first recesses 8b can overlap each other without a gap when viewed from the third direction D3 along the first surface 2a and orthogonal to the first direction D1 because the dispersion of the configuration is improved as a whole in the first wiring pad 8. In this case, since the contact area between the first side conductor 10 and the first wiring pad 8 can be further increased, the contact resistance between the first side conductor 10 and the first wiring pad 8 can be reduced. Furthermore, since the first side conductor 10 becomes more difficult to be peeled off from the first wiring pad 8, the display quality of the display device can be further improved.

[0085] In addition, for example Figure 5 As shown in FIG. 2 , when the insulating layer 25 is located between the metal layer 83 and the insulating layer 23, the depth of the first recessed portion 8b formed on the first outer surface 8a can be increased. As a result, the contact area between the first side conductor 10 and the first wiring pad 8 can be further increased, and the anchor effect generated between the first side conductor 10 and the first wiring pad 8 can be enhanced. As a result, since the first side conductor 10 becomes more difficult to be peeled off from the first wiring pad 8, the display quality of the display device can be further improved.

[0086] The plurality of second wiring pads 9 each have a second outer surface 9a on the side opposite to the surface facing the second surface 2b. Figure 3 , Figure 4A , Figure 4B As shown in the figure, a plurality of second recesses 9b are formed. In this case, the first side conductor 10 enters at least one of the plurality of second recesses 9b, and the contact area with the second wiring pad 9 is increased compared with the case where the plurality of second recesses 9b are not formed on the second outer surface 9a. In addition, the first side conductor 10 enters at least one of the second recesses 9b, and an anchoring effect is generated between the first side conductor 10 and the second wiring pad 9. As a result, since the first side conductor 10 becomes difficult to peel off from the second wiring pad 9, the display quality of the display device can be improved. The opening shape of each of the plurality of second recesses 9b can be, for example, a circular shape, a rectangular shape with rounded corners, an oval shape, etc., or other shapes.

[0087] The second wiring pad 9 may be, for example, Fig.10As shown in FIG. 1 , the entire second outer surface 9a is covered by the first side conductor 10 connected to the second wiring pad 9. In this case, since the first side conductor 10 enters all of the second recesses 9b among the plurality of second recesses 9b, the contact area between the first side conductor 10 and the second wiring pad 9 can be further increased, and the anchor effect generated between the first side conductor 10 and the second wiring pad 9 can be enhanced. As a result, since the first side conductor 10 becomes more difficult to be peeled off from the second wiring pad 9, the display quality of the display device can be further improved.

[0088] When the second outer surface 9a is made of ITO, IZO or the like and the first side conductor 10 is a cured product of a conductive paste containing Ag, the adhesion between the first side conductor 10 and the second wiring pad 9 tends to be reduced. Fig.11A As shown in the figure, by arranging the plurality of second recesses 9b in a matrix, the contact area between the first side conductor 10 and the second wiring pad 9 can be further increased, and the anchor effect generated between the first side conductor 10 and the first wiring pad 8 can be enhanced. As a result, since the first side conductor 10 becomes more difficult to be peeled off from the second wiring pad 9, the display quality of the display device can be further improved.

[0089] You can also Fig. 11B As shown in FIG. 1 , the end of the concave portion closest to the first side 2aa among the plurality of second concave portions 9b on the first side 2aa side becomes an opening. Figure 8B In addition, regarding the fourth recess 15b, it is also possible to adopt Fig. 11B The structure shown.

[0090] The power supply current supplied from the power supply circuit 7 flows in the second connecting portion 10b located on the second outer surface 9a of the first side conductor 10, roughly in a direction along the second surface 2b and orthogonal to the first side 2aa. Therefore, by arranging a plurality of second recesses 9b in a matrix, the cross-sectional area of ​​the second connecting portion 10b in the direction of flow of the power supply current can be increased, and the resistance of the second connecting portion 10b can be reduced. Thus, the heat generation in the second connecting portion 10b can be suppressed, and the thermal stress generated at the interface between the second connecting portion 10b and the second wiring pad 9 can be reduced. As a result, since the first side conductor 10 becomes more difficult to be peeled off from the second wiring pad 9, the display quality of the display device can be further improved.

[0091] Next, other components of the display device 1 according to the present embodiment will be described.

[0092] The display device 1 further includes a driving circuit 13 as a driving unit; a plurality of third wiring pads 14 ; a plurality of fourth wiring pads 15 ; and a plurality of second side conductors 16 .

[0093] The driving circuit 13 is, for example, Figure 2 As shown in FIG. 1 , the drive circuit 13 is arranged on the second surface 2b of the substrate 2. The drive circuit 13 generates image signals supplied to the plurality of pixel units 6. The drive circuit 13 can be mounted on the second surface 2b using a mounting technology such as COF (Chip On Film). The drive unit can be a drive element having a semiconductor integrated circuit such as IC or LSI.

[0094] For example, the third wiring pads 14 Figure 1 As shown, the third wiring pads 14 are arranged on the first surface 2a at the edge region of the second side 2ab of the first surface 2a. The third wiring pads 14 are wiring pads for supplying image signals generated by the driving circuit 13 to the plurality of pixel portions 6 and are electrically connected to the plurality of source signal lines 5, respectively.

[0095] The third wiring pad 14 may be a single metal layer or a plurality of metal layers may be stacked. The material and structure of the third wiring pad 14 are the same as those of the first wiring pad 8, and thus detailed description thereof will be omitted.

[0096] Each of the plurality of third wiring pads 14 has a third outer surface 14a on the side opposite to the surface facing the first surface 2a. Figure 6 As shown in FIG. 1 , a plurality of third recesses 14b are arranged in a direction parallel to the second side 2ab with a second adjacent interval 14bk therebetween. Thus, the portion of the second adjacent interval 14bk in the third wiring pad 14 becomes a current path through which current easily flows ( Figure 6 The second adjacent interval 14bk in the third wiring pad 14 is a portion where current easily flows because the creepage distance of the third wiring pad 14 including the conductor layer is short and the thickness of the third wiring pad 14 is constant. In addition, the second adjacent interval 14bk is the interval between adjacent recesses in the plurality of third recesses 14b.

[0097] The second adjacent interval 14bk of the display device 1 of this embodiment can be larger than the maximum width of the third recess 14b in the direction parallel to the second side 2ab. In this case, since the width of the second adjacent interval 14bk, which is a current path through which current easily flows in the third wiring pad 14, is larger than the maximum width of the third recess 14b, the increase in resistance of the third wiring pad 14 can be suppressed. In addition, when the width of the third recess 14b in the direction parallel to the second side 2ab is constant, the maximum width can be simply defined as the width. When the maximum width of the third recess 14b in the direction parallel to the second side 2ab is set to w3 and the second adjacent interval 14bk is set to w4, w4 can be set to more than 1 times and less than about 15 times of w3.

[0098] In the display device 1 of the present embodiment, the plurality of third recesses 14 b can adopt various structures similar to the plurality of first recesses 8 b described above.

[0099] The plurality of fourth wiring pads 15 are located on the second surface 2b. The plurality of fourth wiring pads 15 may be, for example, Figure 2 As shown, it is arranged in the edge region on the second side 2ab in a plan view. The material and structure of the fourth wiring pad 15 are the same as those of the second wiring pad 9, and thus detailed description thereof will be omitted.

[0100] The display device 1 may have a configuration in which the number of the plurality of third wiring pads 14 is equal to the number of the plurality of fourth wiring pads 15. The plurality of third wiring pads 14 and the plurality of fourth wiring pads 15 may overlap each other in a plan view.

[0101] The display device 1 includes a fourth routing wiring 17 disposed on the second surface 2b. The fourth routing wiring 17 includes, for example, Mo / Al / Mo, MoNd / AlNd / MoNd, Ag, etc. The fourth routing wiring 17 includes, for example, Figure 2 As shown, the driving circuit 13 and the plurality of fourth wiring pads 15 are connected.

[0102] The plurality of second side surface conductors 16 are arranged from the first surface 2a to the second surface 2b. The plurality of second side surface conductors 16 connect the plurality of third wiring pads 14 and the plurality of fourth wiring pads 15, respectively.

[0103] Since the material and structure of the second side conductor 16 are the same as those of the first side conductor 10 , detailed description thereof will be omitted.

[0104] In the display device 1 of the present embodiment, a plurality of third recesses 14b are formed on the third outer surface 14a of the third wiring pad 14. For this reason, the second side conductor 16 enters at least one of the plurality of third recesses 14b, and the contact area with the third wiring pad 14 is increased compared with the case where the plurality of third recesses 14b are not formed on the third outer surface 14a. In addition, the second side conductor 16 enters at least one of the third recesses 14b, and an anchoring effect is generated between the second side conductor 16 and the third wiring pad 14. As a result, the second side conductor 16 becomes difficult to peel off from the third wiring pad 14, so that the display quality of the display device can be improved. The opening shape of each of the plurality of third recesses 14b can be, for example, a circular shape, a rectangular shape with rounded corners, an oval shape, or other shapes.

[0105] The third wiring pad 14 may be, for example, Figure 6 As shown in FIG. 1 , the entire third outer surface 14a is covered by the second side conductor 16 connected to the third wiring pad 14. In this case, since the second side conductor 16 enters all of the third recesses 14b among the plurality of third recesses 14b, the contact area with the third wiring pad 14 can be further increased, and the anchor effect generated between the second side conductor 16 and the third wiring pad 14 can be enhanced. As a result, since the second side conductor 16 becomes more difficult to be peeled off from the third wiring pad 14, the display quality of the display device can be further improved.

[0106] The plurality of third recesses 14b may be respectively formed as follows, for example Fig. 7A , 7B As shown in FIG. 1 , the groove-shaped portion is elongated in the fourth direction D4 from the second side 2ab to the center side of the first surface 2a in a plan view. The third recessed portion 14b including a plurality of groove-shaped portions can be arranged in parallel with at least a portion of the first recessed portion 8b. In other words, the third recessed portion 14b including a plurality of groove-shaped portions can be arranged in a non-parallel manner with a portion of the recessed portions, or all of the recessed portions can be arranged in parallel.

[0107] In addition, you can Fig. 7A , 7BAs shown in FIG. 1 , the fourth direction D4 is a direction orthogonal to the second side 2ab, and the plurality of third recesses 14b are respectively slot-shaped portions that are elongated in the fourth direction D4 when viewed from above. In this case, the signal current supplied from the drive circuit 13 flows in the third connecting portion 16a located on the third outer surface 14a of the second side conductor 16, roughly along the first surface 2a and in a direction orthogonal to the second side 2ab. Therefore, in the case where the third recess 14b is a slot-shaped portion that is elongated in the fourth direction D4, the third connecting portion 16a enters the third recess 14b, and the cross-sectional area of ​​the third connecting portion 16a in the direction of flow of the signal current can be increased, thereby reducing the resistance of the third connecting portion 16a. That is, the third connecting portion 16a in the third recess 14b can become a good current path. Thus, the heat generation at the third connecting portion 16a can be suppressed, and the thermal stress generated at the interface between the second side conductor 16 and the third wiring pad 14 can be reduced. As a result, since the second side conductor 16 becomes more difficult to be peeled off from the third wiring pad 14, the display quality of the display device can be further improved. Furthermore, the fourth direction D4 can be a direction orthogonal to the second side 2ab, and the third recessed portion 14b including a plurality of groove-shaped portions can be arranged in parallel. In this case, since the width of the current path in the third wiring pad 14 does not change, the function of making it easier for current to flow can be maintained.

[0108] The plurality of third recesses 14b may extend substantially over the entire third outer surface 14a in the fourth direction D4. In this case, the resistance of the third connecting portion 16a can be effectively reduced. Thus, the heat generated in the third connecting portion 16a can be effectively suppressed, and the thermal stress generated at the interface between the second side conductor 16 and the third wiring pad 14 can be reduced. As a result, since the second side conductor 16 is more difficult to be removed from the third wiring pad 14, the display quality of the display device can be further improved.

[0109] The plurality of third recesses 14b may be, for example, Fig. 8A , 8B 9, in a plan view, the fourth direction D4 and the fifth direction D5 intersecting the fourth direction D4 are arranged in a matrix. The angle between the fourth direction D4 and the fifth direction D5 in a plan view can be, for example, Fig. 8A , 8B As shown, it is 90°, for example, it can also be Fig. 9 As shown in the figure, it is larger than 0° and smaller than 90°. The plurality of third recesses 14b may be arranged in a matrix of a plurality of rows and a plurality of columns.

[0110] When a plurality of third recesses 14b are arranged in a matrix, more third recesses 14b can be efficiently formed on the third outer surface 14a, compared with the case where a plurality of third recesses 14b are not arranged in a matrix. For this reason, the contact area between the second side conductor 16 and the third wiring pad 14 can be further increased, and the anchoring effect generated between the second side conductor 16 and the third wiring pad 14 can be improved. Furthermore, the cross-sectional area of ​​the third connecting portion 16a in the direction of flow of the signal current can be increased, and the resistance of the third connecting portion 16a can be reduced. As a result, since the heat generation in the third connecting portion 16a can be effectively suppressed, and the thermal stress generated at the interface between the third connecting portion 16a and the third wiring pad 14 can be suppressed, the second side conductor 16 becomes more difficult to be peeled off from the third wiring pad 14. Furthermore, the display quality of the display device can be further improved.

[0111] In addition, for example Fig. 9 As shown in FIG. 1 , when the angle between the fourth direction D4 and the fifth direction D5 is smaller than 0° and smaller than 90° in a plan view, that is, when the plurality of third recesses 14b are arranged in a staggered manner in a plan view, the dispersion of the arrangement of the plurality of third recesses 14b in the third wiring pad 14 can be improved (set to a more uniformly dispersed arrangement as a whole). As a result, the local heat generation in the second side conductor 16 can be suppressed, and the possibility of large thermal stress being locally generated at the interface between the third wiring pad 14 and the second side conductor 16 can be reduced. As a result, since the second side conductor 16 becomes more difficult to be peeled off from the third wiring pad 14, the display quality of the display device can be further improved.

[0112] Furthermore, when the plurality of third recesses 14b are arranged in a staggered manner when viewed from above, the plurality of third recesses 14b can overlap each other without a gap when viewed from the sixth direction D6 along the first surface 2a and orthogonal to the fourth direction D4, because the dispersion of the configuration is improved as a whole in the third wiring pad 14. In this case, since the contact area between the second side conductor 16 and the third wiring pad 14 can be further increased, the contact resistance between the second side conductor 16 and the third wiring pad 14 can be reduced. As a result, since the second side conductor 16 becomes more difficult to be peeled off from the third wiring pad 14, the display quality of the display device can be further improved.

[0113] In addition, for example Figure 5As shown in FIG. 1 , when the insulating layer 25 is located between the metal layer 83 and the insulating layer 23, the depth of the third recess 14b formed on the third outer surface 14a can be increased. As a result, the contact area between the second side conductor 16 and the third wiring pad 14 can be further increased, and the anchor effect generated between the second side conductor 16 and the third wiring pad 14 can be enhanced. As a result, since the second side conductor 16 becomes more difficult to be peeled off from the third wiring pad 14, the display quality of the display device can be further improved.

[0114] Each of the plurality of fourth wiring pads 15 has a fourth outer surface 15a on the side opposite to the surface facing the second surface 2b. Fig.10 , 11A 11B, a plurality of fourth recesses 15b are formed. In this case, the second side conductor 16 enters at least one of the plurality of fourth recesses 15b, and the contact area with the fourth wiring pad 15 is increased compared with the case where the plurality of fourth recesses 15b are not formed on the fourth outer surface 15a. In addition, the second side conductor 16 enters at least one of the fourth recesses 15b, and an anchoring effect is generated between the second side conductor 16 and the fourth wiring pad 15. As a result, since the second side conductor 16 becomes difficult to peel off from the fourth wiring pad 15, the display quality of the display device can be improved. The opening shape of each of the plurality of fourth recesses 15b can be, for example, a circular shape, a rectangular shape with rounded corners, an oval shape, etc., or other shapes.

[0115] The fourth wiring pad 15 may cover the entire fourth outer surface 15a by the second side conductor 16 connected to the fourth wiring pad 15. In this case, since the second side conductor 16 enters all of the fourth recesses 15b among the plurality of fourth recesses 15b, the contact area between the second side conductor 16 and the fourth wiring pad 15 can be further increased, and the anchor effect generated between the second side conductor 16 and the fourth wiring pad 15 can be enhanced. As a result, since the second side conductor 16 becomes more difficult to be peeled off from the fourth wiring pad 15, the display quality of the display device can be further improved.

[0116] When the fourth outer surface 15a is made of ITO, IZO, etc. and the second side conductor 16 is a cured product of a conductive paste containing Ag, the adhesion between the second side conductor 16 and the fourth wiring pad 15 is likely to decrease. Fig.11A , 11BArranging in a matrix as shown can further increase the contact area between the second side conductor 16 and the fourth wiring pad 15, and can enhance the anchor effect generated between the second side conductor 16 and the fourth wiring pad 15. As a result, since the second side conductor 16 becomes difficult to be peeled off from the fourth wiring pad 15, the display quality of the display device is further improved.

[0117] The signal current supplied from the driving circuit 13 flows in the fourth connecting portion 16b located on the fourth outer surface 15a of the second side conductor 16 in a direction generally along the second surface 2b and perpendicular to the second side 2ab. Fig.11A As shown in FIG. 1 , by arranging a plurality of fourth recesses 15b in a matrix, the cross-sectional area of ​​the fourth connection portion 16b in the direction of flow of the signal current can be increased, and the resistance of the fourth connection portion 16b can be reduced. Thus, the heat generated in the fourth connection portion 16b can be suppressed, and the thermal stress generated at the interface between the fourth connection portion 16b and the fourth wiring pad 15 can be reduced. As a result, since the second side conductor 16 becomes more difficult to be peeled off from the fourth wiring pad 15, the display quality of the display device can be further improved.

[0118] According to the display device disclosed in the present invention, since there is a first recess on the first outer surface of the first wiring pad connected to the side conductor, the side conductor is firmly connected to the first wiring pad by the anchoring effect. As a result, since the peeling of the side conductor from the first wiring pad can be suppressed, the display quality of the display device can be improved. In addition, the portion other than the first recess in the first outer surface of the first wiring pad becomes a current path through which current can easily flow. Furthermore, in the case where the side conductor entering the first recess has a relatively large volume and a thick thickness, the side conductor at the portion of the first recess also becomes a current path through which current can easily flow. As a result, the increase in the connection resistance (contact resistance) at the connection portion between the first wiring pad and the side conductor can be suppressed.

[0119] According to the display device disclosed in the present invention, since there are a plurality of first recesses on the first outer surface of the first wiring pad connected to the first side conductor, the first side conductor is firmly connected to the first wiring pad by an anchoring effect. As a result, since the first side conductor can be prevented from peeling off from the first wiring pad, the display quality of the display device can be improved. In addition, since a plurality of first recesses are arranged at first adjacent intervals in a direction parallel to the first side on the first outer surface of the first wiring pad, the first adjacent interval portion at the first wiring pad becomes a current path through which current easily flows. As a result, the resistance increase of the first wiring pad can be prevented.

[0120] The embodiments of the present disclosure are described in detail above, but the present disclosure is not limited to the above-mentioned embodiments, and various changes and improvements can be made within the scope of the gist of the present disclosure. All or part of the above-mentioned embodiments can be appropriately combined within the scope of non-contradiction. For example, the fifth wiring pad 18, the sixth wiring pad 19 and the third gate wiring 22 of the gate wiring can be respectively configured in the same manner as the first wiring pad 8, the second wiring pad 9 and the first side conductor 10. In this case, since the third gate wiring 22 becomes difficult to be peeled off from the fifth wiring pad 18 and the sixth wiring pad 19, the display quality of the display device can be improved.

[0121] Industrial Applicability

[0122] The display device disclosed in the present invention can be applied to various electronic devices. Examples of such electronic devices include composite and large display devices (multi-displays), automobile route guidance systems (navigation systems), ship route guidance systems, aircraft route guidance systems, smart phone terminals, mobile phones, tablet terminals, personal digital assistants (PDAs), video cameras, digital still cameras, electronic notepads, electronic dictionaries, personal computers, copiers, terminal devices for gaming devices, televisions, product display labels, price display labels, commercial preprogrammable display devices, car audio, digital audio players, fax machines, printers, cash automatic deposit and withdrawal machines (ATMs), vending machines, digital display watches, smart watches, and guidance display devices installed at stations and airports.

[0123] Explanation of symbols

[0124] 1 Display device

[0125] 2 substrate

[0126] 2a Page 1

[0127] 2aa Side 1

[0128] 2ab Side 2

[0129] 2b Side 2

[0130] 2c Side 3

[0131] 2e Insulation layer

[0132] 3 Display

[0133] 4 Gate signal lines

[0134] 5 Source signal line

[0135] 6 Pixels

[0136] 61, 61R, 61G, 61B light emitting elements

[0137] 62 electrode pad

[0138] 62a Anode pad

[0139] 62b Cathode pad

[0140] 7 Power supply circuit

[0141] 8 1st wiring pad

[0142] 8a 1st outer surface

[0143] 8b 1st concave part

[0144] 8bk 1st adjacent interval

[0145] 81 Metal Layer

[0146] 81 1st pad

[0147] 82 2nd pad

[0148] 83, 84 Metal layer

[0149] 9 2nd wiring pad

[0150] 9a Second outer surface

[0151] 9b 2nd concave part

[0152] 91 3rd pad

[0153] 92 4th pad

[0154] 93 Metal Layer

[0155] 10 1st side conductor

[0156] 10a First connection part

[0157] 10b Second connection part

[0158] 10c Protective insulation layer

[0159] 11a 1st routing wiring

[0160] 11b Second routing wiring

[0161] 12 3rd lead wiring

[0162] 13. Driving Circuit

[0163] 14 3rd wiring pad

[0164] 14a 3rd outer surface

[0165] 14b 3rd recess

[0166] 14bk 2nd adjacent interval

[0167] 15 4th wiring pad

[0168] 15a 4th outer surface

[0169] 15b 4th recess

[0170] 16 2nd side conductor

[0171] 16a Third connection

[0172] 16b 4th connection

[0173] 17 4th lead wiring

[0174] 18 5th wiring pad

[0175] 19 6th wiring pad

[0176] 20 1st gate wiring

[0177] 21 Second gate wiring

[0178] 22 3rd gate wiring.

Claims

1. A display device comprising: A substrate having a first surface, a side surface, and a second surface opposite to the first surface; A display unit, located on the first surface, having a pixel unit; a first wiring pad located at an edge region on one side of one side of the first surface and electrically connected to the pixel portion; a first recessed portion located on a first outer surface of the first wiring pad; a second wiring pad located at a portion corresponding to the first wiring pad in an end edge region on one side of the side on the second surface; and a side conductor provided from the first surface to the second surface via the side surface, connecting the first wiring pad and the second wiring pad, The first wiring pad has a multilayer structure in which a plurality of metal layers are stacked. The first recessed portion has a step because the maximum width gradually decreases as it goes in the depth direction.

2. The display device according to claim 1, wherein: The number of steps on the first side of the first recess is greater than the number of steps on the side of the first recess opposite to the first side.

3. The display device according to claim 1 or 2, wherein: The width of the first recessed portion on one side of the first side in a direction parallel to the first side is smaller than the width of the first recessed portion on the side opposite to the first side in a direction parallel to the first side.

4. The display device according to claim 1, wherein: The second wiring pad has: a second recessed portion located on the second outer surface; The side conductor covers the first outer surface and the second outer surface.

5. A display device comprising: A substrate having a first surface, a side surface, and a second surface opposite to the first surface; A display unit, arranged on the first surface, comprising: a plurality of gate signal lines, a plurality of source signal lines arranged to intersect the plurality of gate signal lines, and a plurality of pixel units arranged corresponding to intersections of the plurality of gate signal lines and the plurality of source signal lines; a power supply unit, disposed on the second surface, generating a power supply voltage to be supplied to the plurality of pixel units; A plurality of first wiring pads are arranged at an edge region of a first side of the first surface on the first surface and connected to the plurality of pixel portions, and a plurality of first recesses are arranged at first adjacent intervals in a direction parallel to the first side on a first outer surface of each first wiring pad on a side opposite to a surface opposite to the first surface; a plurality of second wiring pads, arranged on the second surface and connected to the power supply unit; a plurality of first side surface conductors, arranged from the first surface to the second surface via the side surface, respectively connecting the plurality of first wiring pads and the plurality of second wiring pads; The first wiring pad has a multilayer structure in which a plurality of metal layers are stacked. The first recessed portion has a step because the maximum width gradually decreases as it goes in the depth direction.

6. The display device according to claim 5, wherein: The number of steps on the first side of the first recess is greater than the number of steps on the side of the first recess opposite to the first side.

7. The display device according to claim 5, wherein: The width of the first recessed portion on one side of the first side in a direction parallel to the first side is smaller than the width of the first recessed portion on a side opposite to the first side in a direction parallel to the first side.

8. The display device according to claim 5, wherein: The first adjacent interval is larger than a maximum width of the first recessed portion in a direction parallel to the first side.

9. The display device according to claim 5, wherein: When observing the first surface in a top view, the multiple first recesses are respectively elongated groove-shaped portions in the first direction from the first side toward the central side of the first surface, the end of the first side of at least a part of the multiple first recesses becomes an opening portion, and the first direction is a direction orthogonal to the first side.

10. The display device according to claim 9, wherein: The plurality of first recessed portions are arranged in parallel.

11. The display device according to claim 9, wherein: When the first surface is viewed from above, the plurality of first recesses are arranged in a matrix in the first direction and in a second direction intersecting the first direction. An end portion of a recessed portion closest to the first side among the plurality of first recessed portions, which is located on the first side, serves as an opening.

12. The display device according to any one of claims 5 to 10, wherein: A plurality of second recessed portions are formed on a second outer surface of each of the plurality of second wiring pads on the side opposite to a surface facing the second surface.

13. The display device according to any one of claims 5 to 10, wherein: The display device further comprises: a driving unit, disposed on the second surface, generating image signals to be supplied to the plurality of pixel units; A plurality of third wiring pads are arranged on the first surface at an edge region of a second side connected to the first side, and are electrically connected to the plurality of source signal lines, respectively; and a plurality of third recesses are arranged at second adjacent intervals in a direction parallel to the second side on a third outer surface of each third wiring pad on a side opposite to a surface opposite to the first surface. a plurality of fourth wiring pads, arranged on the second surface and connected to the driving unit; and The plurality of second side surface conductors are arranged from the first surface to the second surface via the side surface, and respectively connect the plurality of third wiring pads and the plurality of fourth wiring pads.

14. The display device according to claim 13, wherein: The second adjacent interval is larger than a maximum width of the third recessed portion in a direction parallel to the second side.

15. The display device according to claim 13, wherein: The plurality of third recessed portions are respectively groove-shaped portions elongated in a third direction from the second side toward the center side of the first side when the first surface is viewed from above, and the third direction is a direction orthogonal to the second side.

16. The display device according to claim 15, wherein: The plurality of third recesses are arranged in parallel.

17. The display device according to claim 15, wherein: The plurality of third recesses are arranged in a matrix in the third direction and in a fourth direction intersecting the third direction when the first surface is viewed in a plan view.

18. The display device according to claim 13, wherein: The entire third outer surface of each of the plurality of third wiring pads is covered by the plurality of second side-surface conductors.

19. The display device according to claim 13, wherein: A plurality of fourth recessed portions are formed on a fourth outer surface of each of the plurality of fourth wiring pads on the side opposite to a surface facing the second surface.

20. The display device according to claim 19, wherein: The entirety of the fourth outer surface of each of the plurality of fourth wiring pads is covered by the plurality of second side-surface conductors.

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