Display device and method for manufacturing the same

Abstract

The display device of the present disclosure includes: a substrate having a first surface and a second surface opposite to the first surface; a pixel portion located on the first surface and including a light-emitting element; a first connection pad disposed close to an edge of the substrate on the first surface and connected to the pixel portion; a second connection pad disposed close to an edge on the second surface; and a connection conductor extending from the first surface to the second surface and connecting the first connection pad and the second connection pad. The position of the center of the first connection pad is different from the position of the center of the second connection pad in a top view.

Description

Technical Field

[0001] The present disclosure relates to a display device and a method of manufacturing the display device. Background Art

[0002] There is known a display device including a pixel portion having a self-luminous type light-emitting element such as a light-emitting diode element or an organic electroluminescent element (for example, see Patent Document 1). Further, there is known a composite and large display device formed by tiling a plurality of display devices (hereinafter, also referred to as a multi-display) (for example, see Patent Document 2).

[0003] In recent years, improvement in display quality of a multi-display has been expected. Along with this, regarding a display device constituting a multi-display, it is desired to reduce a pixel pitch to make a display portion highly precise, and to reduce an area of a border region around the display portion to achieve narrow bezeling. There is room for improvement in the existing display device with respect to connection, routing, etc. of driving wirings of the display portion in the case of achieving high definition and narrow bezeling.

[0004] Prior Art Documents

[0005] Patent Documents

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 2017-009725

[0007] Patent Document 2: Japanese Patent Application Laid-Open No. 2015-194993 Summary of the Invention

[0008] The display device of the present disclosure is characterized by including:

[0009] a substrate having a first surface and a second surface opposite to the first surface;

[0010] a pixel portion located on the first surface and including a light-emitting element;

[0011] a first connection pad disposed close to an edge of the substrate on the first surface and connected to the pixel portion;

[0012] a second connection pad disposed close to the edge on the second surface; and

[0013] a connection conductor extending from the first surface to the second surface and connecting the first connection pad and the second connection pad,

[0014] wherein a position of a center of the first connection pad is different from a position of a center of the second connection pad in a plan view.

[0015] The method of manufacturing the display device of the present disclosure is characterized by including:

[0016] A preparation process of preparing a mother substrate having a first surface and a second surface opposite to the first surface and including at least one display device area;

[0017] A pixel area forming process of forming a plurality of pixel areas including electrode pads in the display device area on the first surface;

[0018] A first connection pad forming process of forming a plurality of first connection pads at a position close to the edge of the display device area in the display device area on the first surface, and connecting the plurality of electrode pads to the plurality of first connection pads;

[0019] A second connection pad forming process of forming a plurality of second connection pads at a position close to the edge of the display device area in the display device area on the second surface. In this second connection pad forming process, the plurality of second connection pads are formed such that, in a plan view, the minimum value of the distance between the edge of the display device area and each of the plurality of electrode pads, and the minimum value of the distance between the edge and each of the plurality of first connection pads are less than the minimum value of the distance between the edge and each of the plurality of second connection pads; and

[0020] A cutting process of cutting the mother substrate along the edge of the display device area to manufacture a display device substrate having the display device area. Description of the Drawings

[0021] According to the following detailed description and drawings, the objects, features, and advantages of the present disclosure will become clearer.

[0022] Figure 1 It is a diagram showing a schematic circuit structure of circuit wirings and the like on the first surface side of a display device according to an embodiment of the present disclosure.

[0023] Figure 2 It is a diagram showing a schematic circuit structure of circuit wirings and the like on the second surface side of a display device according to an embodiment of the present disclosure.

[0024] Figure 3 It is a plan view showing an enlarged main part of a display device according to an embodiment of the present disclosure.

[0025] Figure 4 It is along Figure 3 A cross-sectional view taken along the cutting plane line A1 - A2.

[0026] Figure 5 It is along Figure 3 A cross-sectional view taken along the cutting plane line A3 - A4.

[0027] Figure 6 is a cross-sectional view cut along the cutting plane line A5 - A6 of Figure 3 .

[0028] Figure 7 is a top view showing an enlarged view of the main part of the display device according to another embodiment of the present disclosure.

[0029] Figure 8A is a top view showing an enlarged view of the main part of the display device according to another embodiment of the present disclosure.

[0030] Figure 8B is along Figure 8A and is a cross-sectional view cut along the cutting plane line A7 - A8 of

[0031] Figure 9 is a flowchart for explaining a manufacturing method of a display device according to an embodiment of the present disclosure.

[0032] Figure 10 is a top view showing an enlarged view of the main part of the display device according to another embodiment of the present disclosure.

[0033] Figure 11 is a top view showing an enlarged view of the main part of the display device according to another embodiment of the present disclosure.

[0034] Figure 12 is a top view showing an enlarged view of the main part of the display device according to another embodiment of the present disclosure. Detailed Embodiments

[0035] Hereinafter, a display device according to an embodiment of the present disclosure will be described with reference to the drawings. In addition, each of the drawings referred to below shows main constituent members and the like of the display device according to the embodiment of the present disclosure. Therefore, the display device according to the embodiment of the present disclosure may also include known structures such as a circuit board, wiring conductors, a control IC, and a control LSI that are not shown.

[0036] Figure 1 is a diagram showing a schematic circuit structure of circuit wirings and the like disposed on the first surface side of a display device according to an embodiment of the present disclosure, Figure 2 is a diagram showing a schematic circuit structure of circuit wirings and the like disposed on the second surface side of a display device according to an embodiment of the present disclosure. Figure 3 is a top view showing an enlarged view of the main part of a display device according to an embodiment of the present disclosure, Figure 4 is along Figure 3 and is a cross-sectional view cut along the cutting plane line A1 - A2 of Figure 5 is along Figure 3 and is a cross-sectional view cut along the cutting plane line A3 - A4 ofFigure 6 is a cross-sectional view cut along the cutting plane line A5 - A6 Figure 3 . Figure 1 It shows a view observed from the first surface side of the substrate, Figure 2 and shows a view observed from the second surface side of the substrate. Additionally, in Figure 3 , for the sake of easy illustration, regarding the pixel portion, elements other than the electrode pads and the light-emitting elements are omitted and illustrated. Further, in Figure 3 , the side conductors as connection conductors are omitted and illustrated.

[0037] The display device 1 includes a substrate 2, a pixel portion 3, a first connection pad 5, a second connection pad 6, and side conductors (also referred to as side wirings) 7 as connection conductors.

[0038] The substrate 2 has a first surface 2a and a second surface 2b on the opposite side of the first surface 2a. The pixel portion 3 is located on the first surface 2a and includes light-emitting elements 32. The first connection pad 5 is disposed close to the edge 2d of the substrate 2 on the first surface 2a and is connected to the pixel portion 3. The second connection pad 6 is disposed close to the edge 2d on the second surface 2b. The side conductors 7 as connection conductors are arranged from the first surface 2a to the second surface 2b and connect the first connection pad 5 and the second connection pad 6. The display device 1 of the present disclosure has a structure in which the position of the center C5 of the first connection pad 5 is different from the position of the center C6 of the second connection pad 6 in a plan view.

[0039] The display device 1 of the present disclosure achieves the following effects through the above structure. The display device 1 can reliably connect the first connection pad 5 and the second connection pad 6, and improve the degree of freedom in arranging the first connection pad 5 and the second connection pad 6. Thereby, the arrangements of the first connection pad 5 and the second connection pad 6 can be set to be suitable for a narrow bezel, and in addition, the connectivity between the first connection pad 5 and the second connection pad 6 can be improved. As a result, a high-definition and narrow-bezel display device 1 with improved reliability can be provided. Therefore, in the case of constituting a multi-display, the display device 1 of the present disclosure can make the pixel pitch of the multi-display uniform, and thus can improve the display quality of the multi-display. Further, it can also be configured to have a structure in which one first connection pad 5 is connected to a plurality of second connection pads 6, a structure in which a plurality of first connection pads 5 are connected to one second connection pad 6, etc. In these cases, as described later, effects such as multifunctionalization and suppression of voltage drop are achieved.

[0040] The center C5 of the first connection pad 5 can be defined by a geometric center, a centroid, etc. When the center C5 of the first connection pad 5 is a geometric center, in the case where the first connection pad 5 is a polygon with symmetry such as a square, a rectangle (including rectangles), a rhombus, or a parallelogram, the center C5 can be the intersection of the diagonals. If the first connection pad 5 is circular, the center C5 can be the center defining the radius. If the first connection pad 5 is elliptical, the center C5 can be the intersection of the major axis and the minor axis. In the case where the first connection pad 5 has other asymmetric shapes, the center C5 can be the centroid. The same applies to the shape and center C6 of the second connection pad 6.

[0041] As Figure 3 shown, the display device 1 of the present disclosure can also have a structure in which the first connection pad 5 and the second connection pad 6 have overlapping portions in a top view. In this case, it is easy to reliably connect the first connection pad 5 and the second connection pad 6. When the size (area) of the first connection pad 5 is different from the size (area) of the second connection pad 6, the above overlapping portion can be about 1% to 70% of the larger one, but is not limited to these values. In addition, when the size of the first connection pad 5 is the same as the size of the second connection pad 6, the above overlapping portion can be about 1% to 80% of one of them, but is not limited to these values.

[0042] In addition, the display device 1 can also have a structure in which at least one of the center C5 of the first connection pad 5 overlaps with the second connection pad 6 and the center C6 of the second connection pad 6 overlaps with the first connection pad 5. In this case, more reliable connectivity between the first connection pad 5 and the second connection pad 6 can be ensured.

[0043] In addition, as Figure 3 shown, the display device 1 can also have a structure in which the position of the center C5 of the first connection pad 5 is offset from the position of the center C6 of the second connection pad 6 in a direction along the edge 2d of the substrate 2. In this case, since the offset between the center C5 and the center C6 is not in the direction where the border portion becomes larger, it is easy to form a narrow-border display device 1.

[0044] In addition, as Figure 7As shown, the display device 1 may also have a structure in which the position of the center C5 of the first connection pad 5 and the position of the center C6 of the second connection pad 6 are offset in a direction intersecting the direction along the edge 2d of the substrate 2. Further, the position of the center C6 of the second connection pad 6 may be farther from the edge 2d of the substrate 2 than the position of the center C5 of the first connection pad 5. In this case, when the substrate 2 is cut out by irradiating the laser from the second surface 2b side of the substrate 2, since the second connection pad 6 is separated from the edge 2d of the substrate 2, it is possible to suppress damage and deterioration of the second connection pad 6 due to the irradiation of the laser and heat. The intersecting direction may be a direction orthogonal to the direction along the edge 2d of the substrate 2, or a direction inclined with respect to the direction along the edge 2d of the substrate 2. The inclination angle of the inclined direction may be about 10° to 80°, but is not limited to these values.

[0045] When the substrate 2 is cut out by irradiating the laser from the second surface 2b side of the substrate 2, in order to achieve the purpose of suppressing damage and deterioration of the second connection pad 6 due to the irradiation of the laser and heat, the width of the second connection pad 6 on the edge 2d side (the width in the direction along the edge 2d) may be smaller than the width of the second connection pad 6 on the side opposite to the edge 2d (the width in the direction along the edge 2d). For example, the second connection pad 6 may be a trapezoidal shape with the side on the edge 2d side as the upper base and the side opposite to the edge 2d as the lower base.

[0046] In addition, the display device 1 may also be configured such that the position of the center C6 of the second connection pad 6 is farther from the edge 2d of the substrate 2 than the position of the center C5 of the first connection pad 5, and the width of the second connection pad 6 on the edge 2d side (the width in the direction along the edge 2d) is smaller than the width of the second connection pad 6 on the side opposite to the edge 2d (the width in the direction along the edge 2d). In this case, when the substrate 2 is cut out by irradiating the laser from the second surface 2b side of the substrate 2, it is possible to further suppress damage and deterioration of the second connection pad 6 due to the irradiation of the laser and heat.

[0047] In addition, as Figure 5 shown, the display device 1 may also be configured such that the substrate 2 has a side surface 2c connecting the first surface 2a and the second surface 2b, and the connection conductor is a side surface conductor 7 that is disposed from the first surface 2a to the second surface 2b via the side surface 2c. In this case, it is advantageous in terms of removing the frame portion of the substrate 2 or forming a frame portion with a minimum area.

[0048] In addition, as Figure 6As shown, the display device 1 may also have a structure in which the side conductor 7 connects a first connection pad 5 to a plurality of second connection pads 6. In this case, processing such as inputting different signals to one first connection pad 5 at different timings, synthesizing different signals and inputting them, etc. can be performed, enabling multifunctionalization. Further, when one first connection pad 5 and a plurality of second connection pads 6 are relay pads for power supply voltage wiring, the area and / or cross-sectional area of the power supply voltage wiring is substantially increased by a plurality of wiring patterns on the second surface 2b that are respectively connected to the plurality of second connection pads 6. As a result, the resistance of the power supply voltage wiring becomes smaller, and a voltage drop in the power supply voltage wiring can be suppressed. Thereby, unevenness in the brightness of the displayed image is improved, and the display quality is enhanced.

[0049] Further, the display device 1 may also be configured such that, in Figure 6 this structure, the thickness of the side conductor 7 on the first connection pad 5 side is thicker than that on the second connection pad 6 side. In this case, for example, when signals with different voltage levels (potentials) are input to one first connection pad 5, due to the voltage drop caused by the resistance of the first connection pad 5, the potential difference between different signals becomes smaller, and the occurrence of defects such as signals being difficult to distinguish can be suppressed. Further, when one first connection pad 5 and a plurality of second connection pads 6 are relay pads for power supply voltage wiring, the resistance between the relay pads becomes smaller, and a voltage drop in the power supply voltage wiring can be suppressed. Thereby, unevenness in the brightness of the displayed image is improved, and the display quality is enhanced.

[0050] The substrate 2 is, for example, a transparent or opaque glass substrate, plastic substrate, 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 side surface 2c that connects the first surface 2a and the second surface 2b. The shape of the substrate 2 can be a triangular plate shape, rectangular plate shape, trapezoidal plate shape, circular plate shape, elliptical plate shape, pentagonal plate shape, hexagonal plate shape, etc., or other shapes. In particular, when the shape of the substrate 2 is a triangular plate shape, rectangular plate shape, hexagonal plate shape, etc., it is a shape suitable for tiling a plurality of display devices and is preferred. In the present embodiment, the shape of the substrate 2 is, for example, as Figure 1 shown, a rectangular plate shape.

[0051] There may also be a plurality of pixel portions 3. The plurality of pixel portions 3 are located on the first surface 2a. For example, as Figure 1 shown, the plurality of pixel portions 3 are arranged in a matrix at a given pixel pitch P. The pixel pitch P can be, for example, about 40 μm to 400 μm, can also be about 40 μm to 120 μm, further, can also be about 60 μm to 100 μm, or can also be about 80 μm.

[0052] Each pixel portion 3 has an electrode pad 31 and a light-emitting element 32 electrically connected to the electrode pad 31.

[0053] The light-emitting element 32 is, for example, a self-luminous element such as a light-emitting diode (LED), an organic electroluminescent element, or a semiconductor laser element. In the present embodiment, an LED is used as the light-emitting element 32. The light-emitting element 32 may also be a micro light-emitting diode (micro LED). In this case, the light-emitting element 32 may have a rectangular top view shape with a side length of about 1 μm or more and about 100 μm or less, or about 3 μm or more and about 10 μm or less in a state of being connected to the electrode pad 31.

[0054] The light-emitting element 32 is electrically connected to the electrode pad 31 via a conductive bonding material such as a conductive adhesive, solder, or an anisotropic conductive film (ACF). In the present embodiment, the electrode pad 31 has an anode pad 31a and a cathode pad 31b, and the anode terminal 32a of the light-emitting element 32 is electrically connected to the anode pad 31a, and the cathode terminal 32b of the light-emitting element 32 is electrically connected to the cathode pad 31b.

[0055] Each pixel portion 3 may also have a plurality of anode pads 31a, a common cathode pad 31b, and a plurality of light-emitting elements 32. The plurality of anode terminals 32a of the plurality of light-emitting elements 32 are respectively electrically connected to the plurality of anode pads 31a, and the plurality of cathode terminals 32b of the plurality of light-emitting elements 32 are electrically connected to the common cathode pad 31b. The plurality of light-emitting elements 32 may also be a light-emitting element 32R that emits red light, a light-emitting element 32G that emits green light, and a light-emitting element 32B that emits blue light. In this case, each pixel portion 3 can perform color grayscale display. In addition, each pixel portion 3 may have a light-emitting element that emits orange light, orange-red light, magenta light, or purple light instead of the light-emitting element 32R that emits red light. Furthermore, each pixel portion 3 may have a light-emitting element that emits yellow-green light instead of the light-emitting element 32G that emits green light.

[0056] A driving unit such as a power supply circuit 4 is located on the second surface 2b of the substrate 2. The driving unit may also include a gate signal line driving circuit (gate driver), a source signal line driving circuit (source driver), and other control circuits. The driving unit may be a thin film circuit having a driving element such as an IC, a circuit board such as an FPC (Flexible Printed Circuit: FPC) on which the driving element is mounted, and a semiconductor layer of low temperature poly silicon (LTPS).

[0057] For example, asFigure 2 As shown, the power supply circuit 4 is located on the second surface 2b. The power supply circuit 4 generates a first power supply voltage VDD and a second power supply voltage VSS applied to the plurality of pixel portions 3. The power supply circuit 4 has a VDD terminal 41 for outputting the first power supply voltage VDD and a VSS terminal 42 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.

[0058] The power supply circuit 4 includes a control circuit for controlling the light emission, non-light emission, light emission intensity, etc. of the light emitting element 32. The power supply circuit 4 can also be, for example, a thin film circuit formed on the second surface 2b of the substrate 2. In this case, the semiconductor layer constituting the thin film circuit can also be, for example, a semiconductor layer including LTPS (Low Temperature Poly Silicon) directly formed on the second surface 2b by a thin film formation method such as CVD. The power supply circuit 4 can also have an IC chip as the control circuit.

[0059] A plurality of first connection pads 5 are located on the first surface 2a at positions close to the edge of the substrate 2. That is, the first connection pads 5 are arranged at positions close to the edge 2d of the substrate 2. The distance between each of the plurality of first connection pads 5 and the edge 2d of the substrate 2 can also be set to about 1 / 2 of the pixel pitch P (for example, about 40μm to 400μm) of the plurality of pixel portions 3. In addition, in the case where a light absorber or the like is inserted between adjacent display devices when tiling a plurality of display devices, etc., the distance between each of the plurality of first connection pads 5 and the edge 2d of the substrate 2 can also be set to be less than 1 / 2 of the pixel pitch P of the plurality of pixel portions 3. The plurality of first connection pads 5 have a plurality of first wiring pads 51 and a plurality of second wiring pads 52. The first wiring pad 51 is a wiring pad for applying the first power supply voltage VDD to the plurality of pixel portions 3, and the second wiring pad 52 is a wiring pad for applying the second power supply voltage VSS to the plurality of pixel portions 3.

[0060] The display device 1 has a first wiring pattern 8 and a second wiring pattern 9. The first wiring pattern 8 and the second wiring pattern 9 are located on the first surface 2a. The first wiring pattern 8 and the second wiring pattern 9 include, for example, Mo / Al / Mo, MoNd / AlNd / MoNd, etc. Here, "Mo / Al / Mo" represents a laminated structure in which an Al layer is laminated on a Mo layer and a Mo layer is laminated on the Al layer. The same applies to others. For example, as Figure 1As shown, the first wiring pattern 8 connects the plurality of pixel portions 3 to the plurality of first wiring pads 51, and the second wiring pattern 9 connects the plurality of pixel portions 3 to the plurality of second wiring pads 52. The first wiring pattern 8 and the second wiring pattern 9 may also be planar wiring patterns. In this case, the first wiring pattern 8 and the second wiring pattern 9 are electrically insulated from each other by an insulating layer (the insulating layers 34 and 35 described later) disposed therebetween. The anode pad 31a of the electrode pad 31 may be formed as a part of the first wiring pattern 8.

[0061] The plurality of second connection pads 6 are located on the second surface 2b. The second connection pads 6 are disposed at positions close to the edge 2d of the substrate 2. The plurality of second connection pads 6 include a plurality of third wiring pads 61 and a plurality of fourth wiring pads 62. The third wiring pad 61 is a wiring pad for applying a first power supply voltage VDD to the plurality of pixel portions 3, and the fourth wiring pad 62 is a wiring pad for applying a second power supply voltage VSS to the plurality of pixel portions 3.

[0062] The display device 1 has a structure in which the number of the plurality of first wiring pads 51 is equal to the number of the plurality of third wiring pads 61, and the number of the plurality of second wiring pads 52 is equal to the number of the plurality of fourth wiring pads 62. At least a part of the plurality of first wiring pads 51 may overlap with at least a part of the plurality of third wiring pads 61 in a top view. In addition, at least a part of the plurality of second wiring pads 52 may overlap with at least a part of the plurality of fourth wiring pads 62 in a top view.

[0063] The display device 1 has a third wiring pattern 10. The third wiring pattern 10 is located on the second surface 2b. The third wiring pattern 10 includes, for example, Mo / Al / Mo, MoNd / AlNd / MoNd, etc. For example, as Figure 2 shown, the third wiring pattern 10 connects the VDD terminal 41 of the power supply circuit 4 to the plurality of third wiring pads 61, and connects the VSS terminal 42 of the power supply circuit 4 to the plurality of fourth wiring pads 62.

[0064] The display device 1 includes a plurality of connection conductors that are disposed from the first surface 2a to the second surface 2b and connect a plurality of first connection pads 5 and a plurality of second connection pads 6 respectively. A plurality of side conductors 7 among the plurality of connection conductors are disposed from the side surface 2c of the substrate to the first surface 2a and the second surface 2b. The plurality of side conductors 7 electrically connect the plurality of first connection pads 5 and the plurality of second connection pads 6 respectively. The plurality of side conductors 7 electrically connect the plurality of first wiring pads 51 and the plurality of third wiring pads 61 respectively, and electrically connect the plurality of second wiring pads 52 and the plurality of fourth wiring pads 62 respectively. The connection conductors are not limited to the side conductors 7, and may also be through conductors that are disposed at the peripheral portion of the substrate 2 and penetrate from the first surface 2a to the second surface 2b. Among them, the side conductors 7 are advantageous in terms of eliminating the frame portion of the substrate 2 or making the area of the frame portion the minimum.

[0065] Next, with reference to Figures 3 - 6 , the detailed structures of the pixel portion 3, the first connection pad 5, and the second connection pad 6 will be described.

[0066] In the present embodiment, as Figure 3 shown, the electrode pad 31 of each pixel portion 3 has three anode pads 31a and a cathode pad 31b. Each pixel portion 3 has a light-emitting element 32R that emits red light, a light-emitting element 32G that emits green light, and a light-emitting element 32B that emits blue light. The light-emitting elements 32R, 32G, and 32B can be arranged in an L shape in a top view, for example, as Figure 3 shown. Thus, the area of the pixel portion 3 in a top view becomes smaller, and the shape of the pixel portion 3 in a top view can be a compact square or the like. Furthermore, the pixel density of the display device 1 can be increased, and high-quality image display can be performed.

[0067] For example, as Figure 4 shown, each pixel portion 3 has insulating layers 33 to 36 on the first surface 2a of the substrate 2. The insulating layers 33 to 36 include, for example, inorganic insulating layers such as SiO 2 , Si 3 N 4 or organic insulating layers such as acrylic resin and polycarbonate. For example, the insulating layers 34 and 35 are inorganic insulating layers, and the insulating layers 33 and 36 are organic insulating layers. In addition, although not shown, inside the insulating layer 33 closest to the substrate 2 among the insulating layers 33 to 36 or between the substrate 2 and the insulating layer 33, TFTs or the like for controlling the light emission of the light-emitting element 32 are disposed. The insulating layers 34 and 35 are disposed between the first wiring pattern 8 and the second wiring pattern 9, and the first wiring pattern 8 and the second wiring pattern 9 are electrically insulated from each other through the insulating layers 34 and 35.

[0068] The anodic terminal 32a of the light-emitting element 32 is electrically connected to the anode pad 31a, which is part of the first wiring pattern 8, by ACF or the like, and the cathodic terminal 32b is electrically connected to the cathode pad 31b formed in the opening of the first wiring pattern 8 by ACF or the like. The anode pad 31a and the cathode pad 31b are electrically insulated from each other by the opening (cutout) of the first wiring pattern 8 formed around the anode pad 31a. The cathode pad 31b is wound around the surfaces of the insulating layers 35 and 36 and the inner wall surfaces of the openings of the insulating layers 35 and 36, and is electrically connected to the second wiring pattern 9. The surfaces of the anode pad 31a and the cathode pad 31b may also be covered with a transparent conductive layer 37 containing indium tin oxide (ITO), indium zinc oxide (IZO), or the like, respectively.

[0069] The first connection pad 5 and the second connection pad 6 contain a conductive material. The first connection pad 5 and the second connection pad 6 may be a single metal layer or may have multiple metal layers laminated. The first connection pad 5 and the second connection pad 6 contain, for example, Al, Al / Ti, Ti / Al / Ti, Mo, Mo / Al / Mo, MoNd / AlNd / MoNd, Cu, Cr, Ni, Ag, etc. In addition, "MoNd" represents an alloy of Mo and Nd. In Figure 5 , 6 , an example is shown in which the first connection pad 5 is composed of two metal layers 53 and 54 laminated on each other and is disposed on the insulating layer 55 formed on the first surface 2a of the substrate 2. In addition, in Figure 5 , 6 , an example is shown in which the second connection pad 6 is composed of a single metal layer 63 and is disposed on the second surface 2b of the substrate 2. In addition, in Figure 5 , the symbol 64 represents an insulating protective layer (outer coating).

[0070] When multiple metal layers 53 and 54 are laminated to form the first connection pad 5, for example, as shown in Figure 5 , an insulating layer 56 may be disposed in a part between the metal layers 53 and 54. In addition, an insulating layer 57 may be disposed at the end on the inner side (the right side in Figure 5 ) of the first surface 2a of the first connection pad 5. Thereby, short circuit between the first connection pad 5 and a wiring conductor or the like disposed on the inner side of the first surface 2a can be suppressed. The insulating layer 55 contains, for example, SiO 2 , Si 3 N 4 , a polymer material such as an acrylic resin, etc. The surface of the first connection pad 5 may also be covered with a transparent conductive layer 58 containing ITO, IZO, or the like. The surface of the second connection pad 6 may also be covered with a transparent conductive layer 65 containing ITO, IZO, or the like.

[0071] For example, asFigure 5 , 6 As shown, the side conductor 7 is arranged from the side surface 2c to the first surface 2a and the second surface 2b, connecting the first connection pad 5 and the second connection pad 6. For example, as Figure 6 shown, the side conductor 7 may also have a structure in which the portion arranged on the side surface 2c extends in a direction inclined with respect to the thickness direction of the substrate 2 ( Figure 6 the up and down direction in this case). In this case, the degree of freedom in arranging the first connection pad 5 and the second connection pad 6 is increased. In addition, a plurality of second connection pads 6 can be connected to one first connection pad 5, one second connection pad 6 can be connected to a plurality of first connection pads 5, and a plurality of second connection pads 6 can be connected to a plurality of first connection pads 5. The side conductor 7 can be formed by methods such as a heating method, a photocuring method such as ultraviolet light irradiation, or a photocuring heating method after applying a conductive paste containing conductive particles such as Ag, Cu, Al, stainless steel, an uncured resin component, an alcohol solvent, and water to a desired portion from the side surface 2c to the first surface 2a and the second surface 2b. The side conductor 7 can also be formed by thin film formation methods such as electroplating, evaporation plating, and CVD. In addition, a groove can be formed in advance at the portion of the side surface 2c where the side conductor 7 is to be formed. Thereby, the conductive paste forming the side conductor 7 can be easily arranged at a desired portion of the side surface 2c.

[0072] Although not shown, the display device 1 is provided with a plurality of gate signal lines and a plurality of source signal lines intersecting the plurality of gate signal lines on the first surface 2a. In addition, each pixel portion 3 includes a plurality of first electrode pads respectively connected to the plurality of gate signal lines, a plurality of second electrode pads respectively connected to the plurality of source signal lines, and a thin film transistor (Thin Film Transistor: TFT) for driving a light emitting element connected to the first electrode pad and the second electrode pad. In addition, although not shown, the display device 1 has a plurality of third electrode pads respectively electrically connected to the plurality of first electrode pads and a plurality of fourth electrode pads respectively electrically connected to the plurality of second electrode pads on the second surface 2b. The plurality of first electrode pads and the plurality of third electrode pads can be respectively electrically connected via a side conductor having the same structure as the side conductor 7, for example. The plurality of second electrode pads and the plurality of fourth electrode pads can be respectively electrically connected via a side conductor having the same structure as the side conductor 7, for example. The third electrode pad is connected to a gate signal line driving circuit (gate driver) arranged on the second surface 2b via a back surface wiring or the like, and the fourth electrode pad can also be connected to a source signal line driving circuit (source driver) arranged on the second surface 2b via a back surface wiring or the like. The gate signal line driving circuit and the source signal line driving circuit can be provided in the power supply circuit 4.

[0073] For example, as Figure 3As shown, when viewed from above, the display device 1 may also have a structure in which the center C5 of at least one of the plurality of first connection pads 5 is offset from the center C6 of the second connection pad 6 connected to the at least one first connection pad 5 in the direction along the edge 2d. In the display device 1, since the offset between the centers C5 and C6 when viewed from above is allowed, the degree of freedom in arranging the plurality of first connection pads 5 and the plurality of second connection pads 6 can be increased. As a result, all of the plurality of first connection pads 5 and the plurality of second connection pads 6 can be arranged in a region close to the edge 2d, and high definition and narrow bezel of the display device 1 can be achieved.

[0074] In the display device 1, since the centers C5 and C6 are offset in the direction along the edge 2d, the possibility of the pixel pitch P changing due to an increase in the degree of freedom in arranging the plurality of first connection pads 5 and the plurality of second connection pads 6 can be reduced. As a result, the display quality of the display device 1 can be improved.

[0075] In addition, in the display device 1, for example, as Figure 5 , 6 shown, side conductors 7 are used to connect the first connection pads 5 and the second connection pads 6 respectively. Therefore, even when the center C5 of the first connection pad 5 is offset from the center C6 of the second connection pad 6, the first connection pad 5 and the second connection pad 6 with the centers C5 and C6 offset from each other can be reliably connected to each other. As a result, the reliability of the display device 1 can be improved.

[0076] As described above, according to the display device 1, the first connection pad 5 and the second connection pad 6 can be reliably connected, and the degree of freedom in arranging the first connection pad 5 and the second connection pad 6 can be increased. Therefore, a high-definition and narrow-bezel display device with improved reliability can be provided. Therefore, according to the display device 1, when a multi-display is configured, the display quality of the multi-display can be improved.

[0077] Next, with reference to Figure 7 , a display device according to another embodiment of the present disclosure will be described. Figure 7 is a plan view showing an enlarged view of the main part of the display device according to another embodiment of the present disclosure. In addition, in Figure 7 , in order to make the illustration easier, elements other than the electrode pads and light-emitting elements of the pixel portion are omitted. In addition, in Figure 7 , the side conductors are omitted from the illustration.

[0078] For example, as Figure 7As shown, when viewed from above, the display device 1 may also have at least one center C5 of the plurality of first connection pads 5 and the center C6 of the second connection pad 6 connected to the at least one first connection pad 5 offset in the direction along the edge 2d ( Figure 7 the up-down direction in Figure 7 ), and in a direction crossing the edge 2d, for example, in a direction orthogonal to the edge 2d (

[0079] the left-right direction in

[0080] ). In this case, the degree of freedom in arranging the plurality of first connection pads 5 and the plurality of second connection pads 6 can be further increased, and it becomes easier to narrow the border of the display device 1. As a result, a high-definition and narrow-border display device 1 with improved reliability can be provided. Further, in the case of forming a multi-display, the display quality of the multi-display can be improved. In addition, in the case where the pixel pitch P changes due to the offset of the center C5 and the center C6 in the direction orthogonal to the edge 2d, the center C5 and the center C6 may be offset only in the direction along the edge 2d. Figure 7 As shown, for example, in the display device 1, when viewed from above, the minimum value of the distances between the edge 2d of the substrate 2 and the respective plurality of electrode pads 31, i.e., the first distance L1, and the minimum value of the distances between the edge 2d and the respective plurality of first connection pads 5, i.e., the second distance L2, may be smaller than the minimum value of the distances between the edge 2d and the respective plurality of second connection pads 6, i.e., the third distance L3. In addition, in the case where the electrode pad 31 has a plurality of anode pads 31a and cathode pads 31b, the distance between the edge 2d and the pad closest to the edge 2d among the plurality of anode pads 31a and cathode pads 31b is set as the first distance L1.

[0081] According to the display device 1, since the first distance L1 is smaller than the third distance L3, the electrode pads 31 among the plurality of electrode pads 31 located at the position closest to the end edge 2d can be arranged close to the end edge 2d. For example, the electrode pads 31 among the plurality of electrode pads 31 located at the position closest to the end edge 2d can be arranged at a distance of about one-half of the pixel pitch P from the end edge 2d. That is, the outermost pixel portions 3 among the plurality of pixel portions 3 arranged in a matrix can be arranged at a distance of about one-half of the pixel pitch P from the end edge 2d. Thus, when a plurality of display devices 1 are combined with each other to form a multi-display, the pixel pitch across one display device 1 and another display device 1 can be made substantially the same as the pixel pitch P of the display device 1. Furthermore, the display quality of the multi-display can be improved.

[0082] For example, in an existing display device, when forming a multi-display, the pixel pitch of the portion across one display device and another display device, that is, the pixel pitch between the pixel (assumed to be pixel P1) closest to the end edge of one display device and the pixel (assumed to be pixel P2) adjacent to pixel P1 and close to the end edge of the other display device, is different from the pixel pitch of the display portion in each display device, and sometimes the display quality of the multi-display is reduced. In addition, for example, when making a plurality of sub-substrates by cutting one mother substrate and making one display device using one sub-substrate, a cutting margin needs to be ensured, so sometimes the pixel pitch between pixel P1 and pixel P2 is different from the pixel pitch of the display portion in each display device. In this way, at the boundary portion (bezel portion) between display devices in a multi-display, the pixel pitch is larger than the pixel pitch of the display portion, so there are portions where the periodic pixel pitch is large, and sometimes a sense of incongruity is felt when a viewer visually recognizes an image. The display device 1 of the present disclosure can suppress such problems from occurring. Therefore, when making a display device capable of reducing the pixel pitch of the display portion and performing high-precision display, when using this display device to make a multi-display, the pixel pitch at the boundary portion between display devices can also be reduced correspondingly to the pixel pitch of the display portion. As a result, a multi-display capable of performing high-precision display can be provided.

[0083] In addition, according to the display device 1, when the second distance L2 is smaller than the third distance L3, at least one of the plurality of first connection pads 5 can be arranged on the first surface 2a at a second distance L2 substantially the same as the first distance L1 from the outermost pixel portions 3 among the plurality of pixel portions 3 arranged in a matrix. Alternatively, at least one of the plurality of first connection pads 5 can be arranged at a position between the outermost pixel portions 3 and the end edge 2d. Thus, the variation in the pixel pitch P caused by the first connection pads 5 being located inside the plurality of pixel portions 3 arranged in a matrix can be suppressed. Furthermore, the display quality of the display device 1 and the display quality of the multi-display formed by a plurality of display devices 1 can be improved.

[0084] The substrate 2 can be manufactured by cutting a mother substrate and dividing it into a plurality of pieces. The mother substrate can be cut by irradiating a laser on the back surface of the mother substrate (the surface corresponding to the second surface 2b). Since the first distance L1 and the second distance L2 are smaller than the third distance L3, when manufacturing the substrate 2, a non-formation region where no conductor such as the second connection pad 6 exists can be arranged around the cutting line where the thermal influence of the laser on the back surface of the mother substrate is large. In addition, due to the thermal influence of the laser around the cutting line, it is larger on the back surface side than on the surface (the surface corresponding to the first surface 2a) side of the mother substrate. Therefore, the non-formation region of the conductor around the cutting line on the back surface of the mother substrate can also be larger than the non-formation region of the conductor around the cutting line on the surface of the mother substrate. According to this structure, the thermal influence of the laser on the second connection pad 6 can be suppressed, and the thermal influence of the laser on the first connection pad 5 can be suppressed.

[0085] The plurality of first connection pads 5 can also be arranged such that all of them are located at an equal distance (i.e., the second distance L2) from the end edge 2d. In this case, the plurality of first connection pads 5 can all be arranged in the portion between the plurality of pixel portions 3 arranged in a matrix in the first surface 2a and the end edge 2d. Thereby, the variation in the pixel pitch P caused by the first connection pads 5 being located inside the plurality of pixel portions 3 arranged in a matrix can be suppressed. Furthermore, the display quality of the display device 1 and the display quality of the multi-display formed by a plurality of display devices 1 can be effectively improved.

[0086] In addition, according to the display device 1, since the third distance L3 is larger than the first distance L1 and the second distance L2, the plurality of second connection pads 6 can be arranged at a position relatively far from the end edge 2d of the second surface 2b. Thus, in the manufacturing process of the display device 1, when cutting off a sub-substrate having the second connection pad 6, the electrode pad 31, and the first connection pad 5 and having a display device region that becomes the display device 1 from the mother substrate, by irradiating a laser from the second surface 2b side to cut the mother substrate, the thermal damage to the second connection pad 6, the electrode pad 31, and the first connection pad 5 can be suppressed, and the sub-substrate having the display device region can be cut off from the mother substrate. Furthermore, the display quality of the display device 1 and the display quality of the multi-display formed by a plurality of display devices 1 can be effectively improved.

[0087] The first distance L1 can be, for example, about 20 μm to 60 μm, can also be about 30 μm to 50 μm, or can also be about 40 μm. The second distance L2 can be, for example, about 20 μm to 60 μm, can also be about 30 μm to 50 μm, or can also be about 40 μm. The third distance L3 can be, for example, about 80 μm to 120 μm, can also be about 90 μm to 110 μm, or can also be about 100 μm.

[0088] The first electrode pad and the second electrode pad provided in the outermost pixel portion 3 on the first surface 2a may also be disposed at a position separated from the edge 2d by a distance approximately the same as the first distance L1 in a plan view. Thereby, the first electrode pad and the second electrode pad connected to the TFT provided in the pixel portion 3 can be disposed at a distance from the edge 2d approximately the same as that of the electrode pad 31. As a result, when a plurality of display devices 1 are combined with each other to form a multi-display, the pixel pitch across one display device 1 and another display device 1 can be effectively made substantially the same as the pixel pitch P of the display device 1.

[0089] In addition, the third electrode pad and the fourth electrode pad disposed on the second surface 2b may also be disposed at a position separated from the edge 2d by a distance equal to or greater than the third distance L3 in a plan view. Thereby, in the manufacturing process of the display device 1, when irradiating laser from the second surface 2b side to cut off the sub-substrate having the display device region that becomes the display device 1 from the mother substrate, thermal damage to the third electrode pad and the fourth electrode pad can be suppressed.

[0090] The first distance L1 and the second distance L2 may also be less than or equal to one-half of the pixel pitch P. In this case, when a plurality of display devices 1 are combined with each other to form a multi-display, the pixel pitch across one display device 1 and another display device 1 can be made the same as the pixel pitch P of the display device 1. As a result, the display quality of the multi-display formed by the plurality of display devices 1 can be effectively improved.

[0091] The first distance L1 and the second distance L2 may also be equal to each other. In this case, for example, when forming the electrode pad 31 and the first connection pad 5 by a method using photolithography or etching, the production of the mask pattern, the positioning of the mask pattern with respect to the substrate 2, etc. become easy. As a result, the electrode pad 31 and the first connection pad 5 can be formed with high precision, and furthermore, the display quality of the display device 1 can be effectively improved.

[0092] The first distance L1 and the second distance L2 may also be less than half of the third distance L3. That is, the third distance L3 may also be more than 2 times the first distance L1 and more than 2 times the second distance L2. In this case, the second connection pad 6 can be disposed at a position far from the edge 2d of the second surface 2b. Thus, in the manufacturing process of the display device 1, when cutting the sub-substrate having the second connection pad 6, the electrode pad 31, and the first connection pad 5 formed thereon and having the display device area that becomes the display device 1 from the mother substrate, by irradiating laser from the second surface 2b side to cut the mother substrate, thermal damage to the second connection pad 6, the electrode pad 31, and the first connection pad 5 can be effectively suppressed, and the sub-substrate having the display device area can be cut from the mother substrate. Furthermore, the display quality of the display device 1 can be effectively improved.

[0093] The display device 1 may also be a non-formation area where no conductor, that is, a conductive film or the like, is disposed in the area of the second surface 2b of the display device 1 that is less than the third distance L3 from the edge 2d, and the second surface 2b of the substrate 2 is exposed. In this case, in the manufacturing process of the display device 1, when cutting the sub-substrate having the second connection pad 6, the electrode pad 31, and the first connection pad 5 formed thereon and having the display device area that becomes the display device 1 from the mother substrate, even if the mother substrate is cut by irradiating laser from the second surface 2b side, it is possible to suppress the scattering of the conductive material constituting the conductor and short-circuiting between the second connection pads 6.

[0094] The non-formation area of the above-mentioned conductor may be provided with a heat shielding layer that makes it difficult for the heat of the laser to conduct to the second connection pad 6 side. The heat shielding layer is an inorganic insulating layer or the like containing materials with low thermal conductivity or high melting points such as silicon nitride, aluminum oxide, silicon carbide, tin oxide, zirconium oxide, titanium oxide, and calcium silicide.

[0095] Next, with reference to Figure 8A 、 8B ,a display device according to another embodiment of the present disclosure will be described. Figure 8A is a top view showing an enlarged main part of the display device according to another embodiment of the present disclosure, Figure 8B is a cross-sectional view taken along the cutting plane line A7 - A8 of Figure 8A . Figure 8B The cross-sectional view shown corresponds to the cross-sectional view shown in Figure 6 . The display device of this embodiment is different from the display device of the above embodiment in that it includes a third connection pad, a plurality of fourth connection pads, and a plurality of second side conductors. For other aspects, since the structure is the same, detailed description of the same structure is omitted. In addition, in Figure 8A , a plurality of second side conductors are omitted from the illustration.

[0096] The display device 1 may further include a third connection pad 11, a plurality of fourth connection pads 12, and a plurality of second side conductors 13.

[0097] The third connection pad 11 is disposed close to the edge 2d on the first surface 2a. The third connection pad 11 is connected to the plurality of pixel portions 3. The third connection pad 11 is connected to the plurality of pixel portions 3 via the first wiring pattern 8 or the second wiring pattern 9.

[0098] The third connection pad 11 includes a conductive material. The third connection pad 11 may be a single metal layer or may have a plurality of metal layers stacked thereon. In the present embodiment, the third connection pad 11 is formed by stacking a plurality of metal layers, and the structure of the third connection pad 11 is the same as that of Figure 5 , 6 the first connection pad 5 shown, and thus the same reference numeral as that of the first connection pad 5 is given to the same structure and detailed description thereof is omitted.

[0099] The plurality of fourth connection pads 12 are disposed close to the edge 2d on the second surface 2b. The plurality of fourth connection pads 12 are connected to the VDD terminal 41 or the VSS terminal 42 of the power supply circuit 4 via the third wiring pattern 10 located on the second surface 2b. When the third connection pad 11 is connected to the first wiring pattern 8, the fourth connection pad 12 is connected to the VDD terminal 41. When the third connection pad 11 is connected to the second wiring pattern 9, the fourth connection pad 12 is connected to the VSS terminal 42.

[0100] The fourth connection pad 12 includes a conductive material. The fourth connection pad 12 may be a single metal layer or may have a plurality of metal layers stacked thereon. In the present embodiment, the fourth connection pad 12 is formed of a single metal layer, and the structure of the fourth connection pad 12 is the same as that of Figure 5 , 6 the second connection pad 6 shown, and thus the same reference numeral as that of the second connection pad 6 is given to the same structure and detailed description thereof is omitted.

[0101] For example, as shown in Figure 8B , the plurality of second side conductors 13 are disposed from the side surface 2c to the first surface 2a and the second surface 2b. The plurality of second side conductors 13 connect the third connection pad 11 and the plurality of fourth connection pads 12, respectively.

[0102] In the present embodiment, the structure and formation method of the second side conductor 13 are the same as those of the side conductor 7, respectively, and thus detailed description thereof is omitted.

[0103] In the display device 1 according to the present embodiment, the area and / or cross-sectional area of the power supply voltage supply wiring is substantially increased by a plurality of wiring patterns on the second surface 2b that are respectively connected to the plurality of fourth connection pads 12. As a result, the resistance of the circuit that supplies the power supply voltage to the plurality of pixel portions 3 can be reduced, and the voltage drop of the power supply voltage supplied to the plurality of pixel portions 3 can be suppressed. As a result, the display quality and reliability of the display device 1 can be improved.

[0104] For example Figure 8A As shown, when viewed from above, the center C11 of the third connection pad 11 and the centers C12 of the plurality of fourth connection pads 12 may also be offset. In this case, the degree of freedom in arranging the third connection pad 11 and the plurality of fourth connection pads 12 can be improved. As a result, the third connection pad 11 and the plurality of fourth connection pads 12 can be arranged in a region close to the edge 2d, and high definition and narrow bezelization of the display device 1 can be achieved. The center C11 and the center C12 may be offset in the direction along the edge 2d ( Figure 8A the up-down direction in Figure 8A ), or in a direction intersecting the edge 2d, for example, a direction orthogonal to the edge 2d (

[0105] As Figure 10 shown, the display device 1 may also be Figure 3In the structure, the first connection pad 5 has an extended protrusion 5e at the end in the offset direction (the direction in which the second connection pad 6 is offset when viewed from above) and at the end on the side of the end edge 2d. In this case, when applying the conductive paste and firing to form the side conductor 7, the conductive paste is easily introduced into the depth direction of the first connection pad 5, and in addition, the overflow of the conductive paste to the outside of the first connection pad 5 can be suppressed. The above-mentioned offset direction is along the end edge 2d, but it can also be any direction. That is, it can also be a structure in which the extended protrusion 5e is located at the end on the side of the end edge 2d that is the end in the offset direction. The size (area) of the extended protrusion 5e can be about 5% to 30% of the size (area) of the main body of the first connection pad 5, but is not limited to this range. The extended protrusions 5e can also be located at both ends on the side of the end edge 2d of the first connection pad 5. In this case, the above-mentioned effect is further improved. In addition, similarly, the second connection pad 6 can also be a structure having an extended protrusion 6e at the end in the offset direction (the direction in which the first connection pad 5 is offset when viewed from above) and at the end on the side of the end edge 2d. In this case, when applying the conductive paste and firing to form the side conductor 7, the conductive paste is easily introduced into the depth direction of the second connection pad 6, and in addition, the overflow of the conductive paste to the outside of the second connection pad 6 can be suppressed. The above-mentioned offset direction is along the end edge 2d, but it can also be any direction. That is, it can also be a structure in which the extended protrusion 6e is located at the end in the offset direction and at the end on the side of the end edge 2d. The size (area) of the extended protrusion 6e can be about 5% to 30% of the size (area) of the main body of the second connection pad 6, but is not limited to this range. The extended protrusions 6e can also be located at both ends on the side of the end edge 2d of the second connection pad 6. In this case, the above-mentioned effect is further improved.

[0106] As Figure 11 shown, in the structure of the display device 1, the first connection pad 5 can also be a trapezoidal shape in which the lower base (the side on the side of the end edge 2d) extends in the offset direction (the direction in which the second connection pad 6 is offset when viewed from above). In this case, it has the same effect as the Figure 3 structure shown. Of course, the upper base of the trapezoidal first connection pad 5 is the side opposite to the end edge 2d. In addition, the second connection pad 6 can also be a trapezoidal shape in which the lower base (the side on the side of the end edge 2d) extends in the offset direction (the direction in which the first connection pad 5 is offset when viewed from above). In this case, it has the same effect as the Figure 10 structure shown. Of course, the upper base of the trapezoidal second connection pad 6 is the side opposite to the end edge 2d. Figure 10 shown, in the structure of the display device 1, the first connection pad 5 can also be a trapezoidal shape in which the lower base (the side on the side of the end edge 2d) extends in the offset direction (the direction in which the second connection pad 6 is offset when viewed from above). In this case, it has the same effect as the

[0107] As Figure 12 shown, in the structure of the display device 1, the first connection pad 5 can also be a trapezoidal shape in which the lower base (the side on the side of the end edge 2d) extends in the offset direction (the direction in which the second connection pad 6 is offset when viewed from above). In this case, it has the same effect as the Figure 3In the structure, the first connection pad 5 can also be a trapezoidal shape that extends in both the offset direction (the direction in which the second connection pad 6 is offset when viewed from above) and the direction opposite to the offset direction from the lower base (the side on the end edge 2d side). In this case, it has the same further improved effect as Figure 10 the structure shown. That is, when applying the conductive paste and firing to form the side conductor 7, the conductive paste is easily introduced in the depth direction of the first connection pad 5, and in addition, the overflow of the conductive paste to the outside of the first connection pad 5 can be further suppressed. Of course, the upper base of the trapezoidal first connection pad 5 is the side opposite to the end edge 2d. In addition, the second connection pad 6 can also be a trapezoidal shape that extends in both the offset direction (the direction in which the first connection pad 5 is offset when viewed from above) and the direction opposite to the offset direction from the lower base (the side on the end edge 2d side). In this case, it has the same further improved effect as Figure 10 the structure shown. That is, when applying the conductive paste and firing to form the side conductor 7, the conductive paste is easily introduced in the depth direction of the second connection pad 6, and in addition, the overflow of the conductive paste to the outside of the second connection pad 6 can be further suppressed. Of course, the upper base of the trapezoidal second connection pad 6 is the side opposite to the end edge 2d.

[0108] Next, a method for manufacturing a display device according to an embodiment of the present disclosure will be described. Figure 9 It is a flowchart for explaining the method for manufacturing a display device according to the embodiment.

[0109] The method for manufacturing a display device according to the present embodiment includes a preparation step S1, a pixel region formation step S2, a first connection pad formation step S3, a second connection pad formation step S4, and a cutting step S5.

[0110] The preparation step S1 is a step of preparing a mother substrate for manufacturing the display device 1. The mother substrate has a first surface and a second surface opposite to the first surface. The mother substrate has at least one display device region that becomes the display device 1.

[0111] The pixel region formation step S2 is a step of forming a plurality of pixel regions arranged in a matrix at a given pitch in the display device region on the first surface 2a. Here, the pixel region refers to, for example, the region obtained by removing the light-emitting element 32 from the Figure 4 pixel portion 3 shown. The pixel region can be formed, for example, by using known methods such as thin film formation methods such as electroplating, evaporation, and CVD, photolithography, and etching.

[0112] The first connection pad forming step S3 is a step of forming a plurality of first connection pads 5 at a position close to the edge of the display device region in the display device region on the first surface 2a and connecting the plurality of electrode pads 31 to the plurality of first connection pads 5. The plurality of first connection pads 5 can be formed, for example, by known methods such as thin film formation methods like electroplating, evaporation, CVD, photolithography, and etching methods.

[0113] The second connection pad forming step S4 is a step of forming a plurality of second connection pads 6 respectively connected to the plurality of first connection pads 5 at a position close to the edge of the display device region in the display device region on the second surface 2b. In the second connection pad forming step S4, the plurality of second connection pads 6 are formed such that, in a top view, the center C5 of at least one of the plurality of first connection pads 5 is offset in a direction along the edge of the display device region with respect to the center C6 of the second connection pad 6 connected to the at least one first connection pad 5. The plurality of second connection pads 6 can be formed, for example, by known methods such as thin film formation methods like electroplating, evaporation, CVD, photolithography, and etching methods.

[0114] In the second connection pad forming step S4, the plurality of second connection pads 6 can also be formed such that the center C5 of at least one of the plurality of first connection pads 5 and the center C6 of the second connection pad 6 connected to the at least one first connection pad 5 are offset in a direction along the edge of the display device region and in a direction orthogonal to the edge of the display device region.

[0115] In the second connection pad forming step S4, the plurality of second connection pads 6 can also be formed such that, in a top view, the minimum value of the distance between the edge of the display device region and the plurality of electrode pads 31 and the minimum value of the distance between the edge of the display device region and the plurality of first connection pads 5 are less than the minimum value of the distance between the edge of the display device region and the plurality of second connection pads 6.

[0116] In addition, the pixel region forming step S2, the first connection pad forming step S3, and the second connection pad forming step S4 can be performed in any order. Furthermore, the pixel region forming step S2 and the first connection pad forming step S3 can also be performed simultaneously.

[0117] The cutting step S5 is a step of cutting the mother substrate along the edge of the display device region to produce a sub-substrate (display device substrate) having the display device region. In the cutting step S5, cutting methods such as mechanical scribing and laser scribing can be used.

[0118] In the cutting step S5, in order to separate the display device region from the mother substrate, it is also possible to irradiate from the second surface 2b side of the mother substrate along the edge of the display device region using irradiation from CO 2A laser scribing method for the laser oscillated from a laser, such as a YAG laser. In this case, compared with the cutting using a mechanical scribing method, the mother substrate can be cut with high precision. In addition, since the second connection pad 6 is arranged at a position far from the edge of the display device area, damage to the second connection pad 6 caused by laser irradiation can be suppressed. Furthermore, a display device 1 with excellent display quality can be manufactured.

[0119] After the cutting step S5, the manufacturing method of the display device of the present embodiment performs a side conductor forming step S6, a step of arranging and connecting a power supply circuit S7, and a light emitting element mounting step S8.

[0120] The side conductor forming step S6 is a step of extending a plurality of side conductors 7 that connect the first surface 2a and the second surface 2b from the side surface 2c of the display device substrate obtained through the cutting step S5 to the first surface 2a and the second surface 2b and respectively connecting a plurality of first wiring pads 51 and a plurality of second wiring pads 52.

[0121] The side conductor 7 can be formed by methods such as applying a conductive paste containing conductive particles such as Ag, Cu, Al, stainless steel, an uncured resin component, an alcohol solvent, and water to a desired portion of the side surface 2c, the first surface 2a, and the second surface 2b of the display device substrate, and then curing it by a heating method, a photocuring method such as ultraviolet light irradiation, a photocuring heating method, etc. The side conductor 7 can also be formed by a thin film forming method such as electroplating, evaporation plating, CVD, etc. A groove can be provided in advance at the portion of the side surface 2c of the display device substrate where the side conductor 7 is to be formed. Thereby, the conductive paste forming the side conductor 7 can be easily arranged at a desired portion of the side surface 2c of the display device substrate.

[0122] The step of arranging and connecting the power supply circuit S7 is a step of arranging the power supply circuit 4 on the second surface 2b and connecting a plurality of second connection pads 6 to the power supply circuit 4. In addition, in the step of arranging and connecting the power supply circuit S7, the prefabricated power supply circuit 4 can be mounted on the second surface 2b of the display device substrate, or it can be directly formed on the second surface 2b of the display device substrate by a known method such as a thin film forming method, a photolithography method, or an etching method using plating, evaporation plating, CVD, etc.

[0123] The light emitting element mounting step S8 is a step of mounting a light emitting element 32 in each of a plurality of pixel regions. As the light emitting element 32, for example, an LED element can be used. The light emitting element 32 can also be a micro LED element. In the light emitting element mounting step S8, three light emitting elements 32R, 32G, and 32B can also be mounted on each of a plurality of pixel regions.

[0124] In addition, the side conductor formation step S6, the arrangement and connection step S7 of the power supply circuit, and the light-emitting element mounting step S8 can also be performed in any order.

[0125] By the above manufacturing method, in the case of constructing a multi-display, a display device 1 that can improve the display quality as a multi-display can be manufactured.

[0126] -Industrial Applicability-

[0127] As described above, the embodiments of the present disclosure have been described in detail. However, the present disclosure is not limited to the above embodiments, and various changes, improvements, etc. can be made without departing from the gist of the present disclosure. All or part of the respective embodiments described above can be appropriately combined within a non-contradictory range.

[0128] In addition, the display device of the present disclosure can be applied to various electronic devices. Examples of such electronic devices include automotive route guidance systems (automotive navigation systems), marine route guidance systems, aircraft route guidance systems, smart phone terminals, mobile phones, tablet terminals, personal digital assistants (PDAs), cameras, digital still cameras, electronic manuals, electronic dictionaries, personal computers, copiers, terminal devices of game devices, televisions, product display labels, price display labels, commercial programmable display devices, automotive audio systems, digital audio players, facsimile machines, printers, automated teller machines (ATMs), vending machines, digital display watches, smart watches, guidance display devices provided at stations and airports, etc.

[0129] -Symbol Explanation-

[0130] 1 Display device

[0131] 2 Substrate

[0132] 2a First surface

[0133] 2b Second surface

[0134] 2c Side surface

[0135] 2d Edge

[0136] 3 Pixel portion

[0137] 31 Electrode pad

[0138] 31a Anode pad

[0139] 31b Cathode pad

[0140] 32, 32R, 32G, 32B Light-emitting elements

[0141] 32a Anode terminal

[0142] 32b Negative terminal

[0143] 33, 34, 35, 36 Insulation layer

[0144] 37 Transparent conductive layer

[0145] 4 Power supply circuit

[0146] 41 VDD terminal

[0147] 42 VSS terminal

[0148] 5 First connection pad

[0149] 5e Extension protrusion

[0150] 51 First wiring pad

[0151] 52 Second wiring pad

[0152] 53, 54 Metal layer

[0153] 55, 56, 57 Insulation layer

[0154] 58 Transparent conductive layer

[0155] 6 Second connection pad

[0156] 6e Extension protrusion

[0157] 61 Third wiring pad

[0158] 62 Fourth wiring pad

[0159] 63 Metal layer

[0160] 64 Insulation protection layer

[0161] 65 Transparent conductive layer

[0162] 7 Side conductor (connection conductor, side wiring)

[0163] 8 First wiring pattern

[0164] 9 Second wiring pattern

[0165] 10 Third wiring pattern

[0166] 11 Third connection pad

[0167] 12 Fourth connection pad

[0168] 13 Second side conductor.

Claims

1. A display device, comprising: a substrate having a first surface and a second surface opposite to the first surface; a pixel portion located on the first surface and including a light-emitting element; a first connection pad disposed close to an edge of the substrate on the first surface and connected to the pixel portion; a second connection pad disposed close to the edge on the second surface; and a connection conductor disposed from the first surface to the second surface and connecting the first connection pad and the second connection pad, wherein positions of centers of the first connection pad and the second connection pad are different in a plan view.

2. The display device according to claim 1, wherein the first connection pad and the second connection pad have overlapping portions in a plan view.

3. The display device according to claim 1 or 2, wherein positions of centers of the first connection pad and the second connection pad are offset in a direction along the edge of the substrate.

4. The display device according to any one of claims 1 to 3, wherein positions of centers of the first connection pad and the second connection pad are offset in a direction intersecting with a direction along the edge of the substrate.

5. The display device according to any one of claims 1 to 4, wherein the substrate has a side surface connecting the first surface and the second surface, and the connection conductor is a side surface conductor disposed from the first surface to the second surface via the side surface.

6. The display device according to claim 5, wherein the side surface conductor connects one of the first connection pads and a plurality of the second connection pads.

7. The display device according to claim 6, wherein a thickness of the side surface conductor on a first connection pad side is thicker than a thickness of the side surface conductor on a second connection pad side.

8. A display device, comprising: a substrate having a first surface and a second surface opposite to the first surface; a plurality of pixel portions disposed on the first surface, each including a light-emitting element and an electrode pad connected to the light-emitting element; a power supply circuit disposed on the second surface and generating a power supply voltage supplied to the plurality of light-emitting elements; a plurality of first connection pads disposed close to an edge of the substrate on the first surface and connected to the plurality of pixel portions; a plurality of second connection pads disposed close to the edge on the second surface and connected to the power supply circuit; and a plurality of connection conductors disposed from the first surface to the second surface and respectively connecting the plurality of first connection pads and the plurality of second connection pads, wherein in a plan view, a minimum value of distances between the edge and respective ones of the plurality of electrode pads, i.e., a first distance, and a minimum value of distances between the edge and respective ones of the plurality of first connection pads, i.e., a second distance, are smaller than a minimum value of distances between the edge and respective ones of the plurality of second connection pads, i.e., a third distance.

9. The display device according to claim 8, wherein The plurality of connection conductors are a plurality of side conductors disposed on the first surface and the second surface from a side surface connecting the first surface and the second surface.

10. The display device according to claim 8 or 9, wherein, The first distance and the second distance are each less than or equal to one half of a pixel pitch of the plurality of pixel portions.

11. The display device according to any one of claims 8 to 10, wherein, The first distance is equal to the second distance.

12. The display device according to any one of claims 8 to 11, wherein, The first distance and the second distance are each less than one half of the third distance.

13. The display device according to any one of claims 8 to 12, wherein, A region of the second surface that is at a distance less than the third distance from the edge is a non-conductor formation region.

14. The display device according to any one of claims 1 to 13, wherein, The light-emitting element includes a micro light-emitting diode.

15. A method of manufacturing a display device, comprising: A preparation step of preparing a mother substrate having a first surface and a second surface opposite to the first surface and including at least one display device region; A pixel region formation step of forming a plurality of pixel regions including electrode pads in the display device region of the first surface; A first connection pad formation step of forming a plurality of first connection pads at a position in the display device region of the first surface close to an edge of the display device region, and connecting the plurality of electrode pads to the plurality of first connection pads; A second connection pad formation step of forming a plurality of second connection pads at a position in the display device region of the second surface close to the edge of the display device region. In this second connection pad formation step, the plurality of second connection pads are formed such that a minimum value of a distance between the edge of the display device region and each of the plurality of electrode pads and a minimum value of a distance between the edge and each of the plurality of first connection pads are less than a minimum value of a distance between the edge and each of the plurality of second connection pads; and A cutting step of cutting the mother substrate along the edge of the display device region to produce a display device substrate having the display device region.

16. The method of manufacturing a display device according to claim 15, wherein, In the cutting step, the mother substrate is cut by laser processing that irradiates laser light along the edge from the second surface side.

17. The method of manufacturing a display device according to claim 15 or 16, wherein, After the cutting step, the following steps are performed: A side conductor formation step of forming a plurality of side conductors that extend from a side surface connecting the first surface and the second surface of the display device substrate to the first surface and the second surface and respectively connect the plurality of first connection pads and the plurality of second connection pads; A power supply circuit arrangement and connection step of arranging a power supply circuit on the second surface and connecting the plurality of second connection pads and the power supply circuit; and Light-emitting element mounting process, mounting light-emitting elements in the respective pixel regions.

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