Display device and composite display device

Abstract

A display device is configured to have: a substrate having a first side and a second side adjacent to the first side; a plurality of light emitting elements on the substrate; a plurality of light emission control signal lines on the substrate and configured to control light emission / non-light emission of the light emitting elements; and a connection pad on the substrate and connected to the plurality of light emission control signal lines, the connection pad being located at an end edge portion on the first side and an end edge portion on the second side.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a display device provided with a light-emitting element such as a light-emitting diode (LED) element, which is a self-luminous type light-emitting element, and a composite display device configured by combining (tiling) a plurality of display devices. BACKGROUND

[0002] The display device and the composite display device of the related art are described, for example, in Patent Documents 1 to 5.

[0003] PRIOR ART DOCUMENTS

[0004] PATENT DOCUMENTS

[0005] Patent Document 1: JP Patent Publication No. 2005-148248

[0006] Patent Document 2: JP Patent Publication No. 57-114189

[0007] Patent Document 3: JP Patent Publication No. 2003-295785

[0008] Patent Document 4: JP Patent Publication No. 2012-104497

[0009] Patent Document 5: JP Patent Publication No. 2007-335429 SUMMARY

[0010] The display device of the present disclosure can be configured to have: a substrate having a first side and a second side adjacent to the first side; a plurality of light-emitting elements on the substrate; a plurality of light-emitting control signal lines on the substrate and configured to control light emission / non-light emission of the light-emitting elements; and a connection pad on the substrate and configured to be connected to the plurality of light-emitting control signal lines, the connection pad being on an end edge portion on the first side and an end edge portion on the second side of the substrate.

[0011] The composite display device of the present disclosure is configured to have a plurality of display devices, the plurality of display devices being configured by combining side surfaces of the plurality of display devices with each other, the plurality of display devices including a first display device and a second display device, and a side surface adjacent to the first side in the first display device and a side surface opposite to the side surface in the second display device being combined. BRIEF DESCRIPTION OF DRAWINGS

[0012] The objects, features, and advantages of the present application will become more apparent from the following detailed description and accompanying drawings.

[0013] Figure 1 is a plan view showing a schematic configuration of a display device according to an embodiment of the present disclosure.

[0014] Figure 2 is a schematic plan view of a display device representing other embodiments of the present disclosure.

[0015] Figure 3 is a partial plan view of a main part of the display device shown in Figure 1

[0016] Figure 4 is a cross-sectional view of the display device shown in Figure 3

[0017] Figure 5 is a partial plan view of a wiring configuration of a main part of the display device shown in Figure 1

[0018] Figure 6 is a partial plan view of a wiring configuration of a main part of the display device shown in Figure 2

[0019] Figure 7 is a partial plan view of a wiring configuration of a main part of a modification example of the display device shown in Figure 2

[0020] Figure 8 is a cross-sectional view of the display device shown in Figure 3

[0021] Figure 9 is a block circuit diagram schematically showing a circuit structure on a first surface side of the display device shown in Figure 1

[0022] Figure 10 is a block circuit diagram schematically showing a circuit structure on a second surface side of the display device shown in Figure 1

[0023] Figure 11 is a circuit diagram showing a structure of a pixel circuit in the display device of the present disclosure.

[0024] Figure 12 is a partial plan view of a wiring configuration of a main part of a modification example of the display device shown in Figure 7

[0025] Figure 13 is a partial plan view of a wiring configuration of a main part of a modification example of the display device shown in Figure 7

[0026] Figure 14 is a partial plan view of a main part of a composite display device of one embodiment of the present disclosure. DETAILED DESCRIPTION

[0027] ​​​​​​​​​​The object, features, and advantages of the present application will become more apparent from the following detailed description and the accompanying drawings.

[0028] First, a structure on which a display device of the present disclosure is based will be described. A large composite display device called a multi-display or a tiled panel, which is configured by laying a plurality of display devices side by side in a planar manner, has been known since the past. The plurality of self-emitting display devices that configure the composite display device are desired to make the frame portion, which is a non-display region, outside the effective display region as small as possible. In addition, each display device sometimes has a substrate for mounting a light-emitting element on one main surface (front surface) side, a driving portion provided on the other main surface (back surface) side of the substrate, and a side surface wiring that electrically connects the light-emitting element and the driving portion and is disposed on the side surface of the substrate. In this case, a one-main-surface-side side surface wiring connection pad connected to the side surface wiring is provided on the end edge portion on the one main surface of the substrate, and an other-main-surface-side side surface wiring connection pad connected to the side surface wiring is provided on the end edge portion on the other main surface of the substrate.

[0029] The above-described structure is sometimes used in a self-emitting display device that has a micro LED (μLED) element as a light-emitting element. In addition, in the past, an organic EL (Electroluminescence) display device that has an organic EL element has also been proposed. On a first surface (front surface, display side surface) of a substrate that configures the organic EL display device, pixel circuits (for example, refer to the aforementioned Patent Documents 1 to 5) that include a thin film transistor (TFT) that drives and controls the organic EL element are arranged in a matrix shape.

[0030] In a case where a plurality of the above-described structure of the self-emitting display device is combined to configure a composite display device, a so-called multi-display, the following aspects are important. That is, it is desired that a pixel pitch (also referred to as a combined portion pixel pitch) between a plurality of pixel portions arranged in an outermost arrangement portion of a combined edge portion in one display device and a plurality of pixel portions arranged in an outermost arrangement portion of a combined edge portion in another display device combined with the above-described one display device is approximately the same as, or the same as, a pixel pitch (also referred to as a non-combined portion pixel pitch) of a plurality of pixel portions arranged outside the outermost arrangement portion. The reason is that, if the combined portion pixel pitch is larger than the non-combined portion pixel pitch, it becomes easy to lose the continuity of the display image at the combined portion, and a visual recognizer feels a sense of incongruity in the display image, or it is easy to visually recognize the combined portion.

[0031] In self-emissive display devices, each of the multiple pixel units is connected to a light-emitting control signal line that supplies light-emitting / non-emitting control signals to the light-emitting element. Furthermore, bonding pads connected to the light-emitting control signal lines are disposed on an outer frame (non-active part) outside the display unit (active part) containing the multiple pixel units on a main surface of the substrate. Since these bonding pads are also connected to side wiring formed by coating conductive paste and firing, they are more difficult to miniaturize compared to light-emitting control signal lines formed by thin-film forming and electrode pads of the pixel units connected to the light-emitting element. Therefore, if multiple bonding pads are to be arranged on one side of the substrate corresponding to a narrow pixel pitch, the spacing between the bonding pads becomes smaller, sometimes making the overall arrangement of the multiple bonding pads difficult. Furthermore, if the area of ​​the bonding pads is reduced, the connection area with the side wiring decreases, increasing the connection resistance. This can sometimes lead to display inhomogeneity and deterioration of display quality. Moreover, if the spacing between the multiple bonding pads becomes smaller, electrical short circuits may occur between the bonding pads.

[0032] Therefore, if multiple connection pads are to be precisely aligned with the pixel pitch in the outer frame on one side of the substrate, the width and length of the outer frame tend to increase. If the width of the outer frame increases, the pixel pitch at the joints tends to become larger than the pixel pitch at the non-joint parts, which are designed for narrower spacing. In other words, it is difficult to make the pixel pitch at the joints equal to the pixel pitch at the non-joint parts. Furthermore, if the length of the outer frame increases along one side of the substrate, the width of the outer frame on the side adjacent to that side of the substrate increases.

[0033] Furthermore, in order to reduce the size of the outer frame, a structure was considered where connection pads were arranged between the outermost pixels on one side of the substrate. However, the number of connection pads that can be arranged along one side of the substrate is (number of pixels - 1), resulting in the problem that not all connection pads can be arranged on one side of the substrate. In the past, technologies have been sought to solve the various problems mentioned above.

[0034] Hereinafter, various embodiments of the display device of this disclosure will be described with reference to the accompanying drawings.

[0035] like Figure 1 As shown, the display device disclosed herein has the following structure: a substrate 2 having a first side m1 and an adjacent second side m2; and a plurality of light-emitting elements 6 located on the substrate 2. Figure 3 (As shown in the diagram); multiple light-emitting control signal lines L1 and L2 located on the substrate 2 and controlling the light-emitting / non-emitting state of the light-emitting element 6; and connection pads 8 located on the first side m1 and the second side m2 of the substrate 2, respectively connected to the multiple light-emitting control signal lines L1 and L2. Additionally, in Figure 1In the present embodiment, the symbol 3 denotes a pixel portion, and the light emitting element 6 is provided in each of a plurality of pixel portions 3. The plurality of pixel portions 3 are arranged in a matrix shape, for example, in an effective region A on the first surface 2a of the substrate 2.

[0036] The display device of the present disclosure has the following effects due to the above-described structure. Since the plurality of connection pads 8, which are difficult to be miniaturized, are arranged on the end edge portion 2el on the first edge ml side and the end edge portion 2e2 on the second edge m2 side of the substrate 2, the interval between the plurality of connection pads 8 can be arranged to be an interval in which an electrical short circuit is difficult to occur. As a result, an electrical short circuit between the plurality of connection pads 8 and an increase in the size of the outer frame portion (approximately equivalent to the end edge portions 2el, 2e2) are suppressed, and the display device can be arranged on the substrate 2. Furthermore, the plurality of connection pads 8 can be arranged on the substrate 2 with a smaller outer frame portion.

[0037] The end edge portion 2el is a portion having a width of about 10 μm to 500 μm from the first edge ml on the first surface 2a of the substrate 2 toward the center side of the first surface 2a, but is not limited to this value. Furthermore, the width of the end edge portion 2el can be about 1 / 2 or less of the pixel pitch. The end edge portion 2e2 and the end edge portion 2e3 (described below) are also the same structure as the end edge portion 2el. Figure 2 The length of one side of the connection pad 8 is about 50 μm to 500 μm, and is preferably about 70 μm to 300 μm, but the length of one side is not limited to these values. Furthermore, the shape of the connection pad 8 can be a polygonal shape such as a 5-sided shape, a trapezoidal shape, a circular shape, an elliptical shape, or the like. In addition, “to” means “to”, and the same applies below.

[0038] The display device of the present disclosure has a plurality of light emission control signal lines L1, L2 that control the light emission / non-light emission of the light emitting element 6, and the light emission control signal lines L1, L2 have the following structure and function. As shown in FIG. 1, the display device has a scan signal line (gate signal line) 102 arranged in a given direction (for example, a row direction) on the first surface 2a of the substrate 2, a light emission control signal line L1 (L2) arranged in a direction intersecting the scan signal line 102 and intersecting the given direction (for example, a column direction), a plurality of pixel portions 3 distinguished by the scan signal line 102 and the light emission control signal line L1 (L2), and a light emitting element 6 provided in each of the pixel portions 3. Figure 11 The scan signal line 102 and the light emission control signal line L1 (L2) are connected to a back surface wiring via a side surface wiring 10 arranged on the side surface 2c of the substrate 2. The back surface wiring is connected to a driving portion such as an IC, an LSI, or the like provided on the second surface (back surface) 2b of the substrate 2. That is, the display device is driven and controlled by the driving portion on the back surface of the substrate 2.

[0039] A light emission control section 122 for controlling light emission, non-light emission, light emission intensity, and the like of the light emitting element 6 is provided in each pixel section 3. The light emission control section 122 includes a thin film transistor (TFT) 112 as a switching element for inputting a light emission signal to the light emitting element 6, and a TFT 113 as a driving element for current driving the light emitting element 6 based on a potential difference (light emission signal) between a positive voltage (anode voltage: about 3 to 15 V) and a negative voltage (cathode voltage: about -3 to 3 V) corresponding to a voltage level of a light emission control signal (a signal transmitted in a light emission control signal line L1(L2)). That is, the light emission control signal line L1(L2) is connected to a source electrode of the TFT 112, the gate voltage of the TFT 113 is controlled by the voltage level of the light emission control signal, and the luminance of the light emitting element 6 is controlled by the source-drain current of the TFT 113 corresponding to the gate voltage level. A capacitor element is provided in a connection line connecting the gate electrode and the source electrode of the TFT 113, and functions as a holding capacitor that holds the voltage of the light emission control signal input to the gate electrode of the TFT 113 for a period (a period of 1 frame) until the next rewriting.

[0040] The light emitting element 6 is electrically connected to the light emission control section 122, a positive power supply (VDD) input line 116, and a negative power supply (VSS) input line 117 via a through conductor 123a, 123b that penetrates a through hole or the like in an insulating layer provided below the light emitting element 6. That is, the positive electrode of the light emitting element 6 is connected to the positive power supply input line 116 via the through conductor 123a and the light emission control section 122, and the negative electrode of the light emitting element 6 is connected to the negative power supply input line 117 via the through conductor 123b.

[0041] Figure 1is a plan view showing a schematic configuration of a display device la according to an embodiment of the present disclosure. The display device la of the self-emission type has the following configuration. The plurality of connection pads 8 include: a plurality of first connection pads 81 provided along the first side ml at the end edge portion 2el on the first side ml of the substrate 2, and connected to the first light emission control signal line Ll that controls light emission / non-emission of each of the light emitting elements 6 in the first group 3a among the plurality of light emitting elements 6; and a second connection pad 82 provided at the end edge portion 2e2 on the second side m2 of the substrate 2, and connected to the second light emission control signal line L2 that controls light emission / non-emission of the light emitting elements 6 in the second group 3b among the plurality of light emitting elements 6. In this configuration, the plurality of first connection pads 81 among the plurality of connection pads 8 can be arranged at the end edge portion 2el at intervals at which short-circuiting is difficult to occur, and the second connection pad 82 that is not arranged at the end edge portion 2el can be arranged at the end edge portion 2e2. As a result, it is possible to reliably suppress occurrence of electrical short-circuiting between the plurality of connection pads 8 and an increase in the size of the outer frame portion, and thus it is possible to arrange the plurality of connection pads 8 on the substrate 2. The intervals at which short-circuiting is difficult to occur are about 30 μm to 100 μm, but are not limited to these values, and can be appropriately set. The light emitting elements 6 in the second group 3b can be light emitting elements 6 included in a group of pixel portions 3 in one column closest to the second side m2 among the plurality of pixel portions 3 arranged in a matrix. For example, in a case where the light emitting elements 6 in the second group 3b are light emitting elements 6 included in a group of pixel portions 3 in two columns closest to the second side m2 among the plurality of pixel portions 3 arranged in a matrix, the second connection pad 82 can be two. Further, the second connection pad 82 can be three or more.

[0042] In Figure 1 the display device, the second connection pad 82 can be arranged at a position closer to the first side than other connection pads connected to wiring other than the second light emission control signal line L2 are arranged at the end edge portion 2e2 on the second side m2 of the substrate 2. In this configuration, as in Figure 5As shown, the length (let's call it length L1c) of the connection portion connecting the first connecting pad 8 and the nearest pixel portion 3 (light-emitting element 6) in the first light-emitting control signal line L1, and the length (let's call it length L2c) of the connection portion connecting the second connecting pad 82 and the nearest pixel portion 3b1 in the second light-emitting control signal line L2, can be made close. That is, the difference between L1c and L2c can be minimized. As a result, the lengths of the first light-emitting control signal line L1 and the second light-emitting control signal line L2 can be made approximately the same, and the resistances of the first light-emitting control signal line L1 and the second light-emitting control signal line L2 can be made approximately the same. Therefore, the following problem can be suppressed: when the same light-emitting control signal is input to the first light-emitting control signal line L1 and the second light-emitting control signal line L2, the current value and voltage level of the light-emitting control signal transmitted in the first light-emitting control signal line L1 are different from those of the light-emitting control signal transmitted in the second light-emitting control signal line L2. As a result, the display quality of the display device is improved. Furthermore, the presence of the second connecting pad 82 prevents the restriction of the freedom of layout for various wirings located on one side of the second surface 2b of the substrate 2. Therefore, the layout of various wirings located on one side of the second surface 2b of the substrate 2 becomes easier.

[0043] Furthermore, the second connection pad 82 can be adjacent to the first connection pad 81a, which is located closest to the second edge m2 among the plurality of first connection pads 8. In this configuration, the aforementioned effects are further enhanced.

[0044] The other connection pads mentioned above can be power connection pads 181 that are connected to the power supply wiring that supplies power to the light-emitting element 6. Figure 9 (as shown in the diagram), or it can be the fifth connection pad 18 connected to the gate signal line 4. Figure 9 (as shown in the image).

[0045] like Figure 5 As shown, Figure 1 In the display device 1a, the structure can be as follows: a plurality of light-emitting elements 6 are included in the edge portion 2e1 on the first side m1 of the substrate 2, and a plurality of outermost light-emitting elements 6m are disposed along the first side m1, with a first connecting pad 81 located between the plurality of outermost light-emitting elements 6m. In this structure, since the first connecting pad 81 is disposed between the outermost pixel portions 3 on the first side m1 of the substrate 2, the outer frame portion in the first side m1 can be made smaller. However, the number of connecting pads 8 that can be disposed along the first side m1 of the substrate 2 is (number of pixels - 1), and not all connecting pads 8 can be disposed on the first side m1 of the substrate 2. Therefore, the remaining one connecting pad 8 (the second connecting pad 82) is disposed on the edge portion 2e2 on the second side m2.

[0046] Further, as shown in Figure 5 In the display device 1a, the light emitting elements 6 of the second group 3b can be arranged along the end edge portion 2e2 of the second side m2, and the second connection pads 82 can be located between the light emitting elements 6 of the second group 3b. In this case, the second connection pads 82 can be arranged between the outermost pixel portions 3 on the second side m2 of the substrate 2, and thus the frame portion on the second side m2 can be made smaller.

[0047] Further, as shown in Figure 7 In the display device 1b, the size of the second connection pads 82 can be larger than the size of the first connection pads 81. In this case, the length L2c of the connection portion connecting the second connection pads 82 and the nearest pixel portion 3b1 in the second light emitting control signal line L2 can be shortened, and thus the length L2c can be made closer to L1c. The lengths L1c and L2c can also be made substantially the same. As a result, the lengths of the first light emitting control signal line L1 and the second light emitting control signal line L2 can be made closer to each other, and the resistance of the first light emitting control signal line L1 and the resistance of the second light emitting control signal line L2 can be made closer to each other. Thus, the problem that the current value and the voltage level of the light emitting control signal transmitted in the first light emitting control signal line L1 and the current value and the voltage level of the light emitting control signal transmitted in the second light emitting control signal line L2 are different when the same light emitting control signal is input to the first light emitting control signal line L1 and the second light emitting control signal line L2 can be more effectively suppressed. Thus, the display quality of the display device 1b can be improved.

[0048] To more effectively achieve the above-described object and effects, the length of the second connection pads 82 in the direction of the second side m2 can be longer than the length of the first connection pads 81 in the direction of the first side m1. Further, as shown in Figure 7 The second connection pads 82 can also have an extension portion extending toward the corner between the first side m1 and the second side m2. That is, the second connection pads 82 can have an extension portion 82e extending toward the first side m1 from the second side m2. The width of the extension portion 82e can be smaller than the width of the main portion of the second connection pads 82. In this case, the width of the frame portion on the second side m2 can be suppressed from becoming large.

[0049] In the display device 1a, the substrate 2 can have a first surface 2a on one side on which the light emitting elements 6 are arranged, and a second surface 2b on the other side opposite the first surface 2a Figure 3 Figure 4 ​a side surface 2c connecting the first surface 2a and the second surface 2b, and a side surface wiring 10, a first connection pad 81, and a second connection pad 82 each connected to the side surface wiring 10, provided from an end edge portion of the first surface 2a to an end edge portion of the second surface 2b via the side surface 2c. In the case of this structure, the driving section can be arranged on the side of the second surface 2b of the substrate 2, and the pixel section 3 and the driving section are electrically connected via the side surface wiring 10. As a result, since the driving section that has been arranged on the outer frame section in the past can be arranged on the side of the second surface 2b, this is advantageous for narrow frame.

[0050] Figure 2 is a plan view showing the schematic structure of a display device lb of another embodiment. Note that the same reference numerals are used for the portions corresponding to those of the aforementioned embodiment. The display device lb of the self-light-emitting type according to the present embodiment has the following structure. The substrate 2 can have a structure in which a third edge m3 is provided adjacent to the first edge ml and opposite to the second edge m2, and a third connection pad 83 is provided at an end edge portion 2e3 on the third edge m3 side of the substrate 2 and connected to a third light-emission control signal line L3 that controls light emission / non-light emission of the light-emitting elements 6 of a third group 3c among the light-emitting elements 6. In the case of this structure, most of the plurality of first connection pads 81 among the plurality of connection pads 8 can be arranged at the end edge portion 2el at intervals at which short circuits are less likely to occur, and the second connection pads 82 and the third connection pads 83 that are not arranged at the end edge portion 2el can be arranged at the end edge portions 2e2 and 2e3. As a result, it is possible to more reliably suppress electrical short circuits between the plurality of connection pads 8 and an increase in the size of the outer frame section, and thus the display device lb can be arranged on the substrate 2. The light-emitting elements 6 of the third group 3c can be light-emitting elements 6 included in a group of pixel sections 3 closest to the third edge m3 among the plurality of pixel sections 3 arranged in a matrix. For example, in the case where the light-emitting elements 6 of the third group 3c are light-emitting elements 6 included in a group of pixel sections 3 closest to two columns of the third edge m3 among the plurality of pixel sections 3 arranged in a matrix, the third connection pad 83 can be two. Furthermore, the second connection pads 82 can also be three or more.

[0051] In the display device lb, as in the display device la, Figure 6As shown, the structure can also be as follows: On the third side m3 of the substrate 2, at the end edge 2e3, other connection pads are provided that connect to wiring other than the third light-emitting control signal line L3. The third connection pad 83 is located closer to the first side ml than the other connection pads. In this structure, the length L1c and the length of the connection portion (let's call it length L3c) connecting the third connection pad 83 and the nearest pixel portion 3c1 in the third light-emitting control signal line L3 can be made close. That is, the difference between L1c and L3c can be minimized. As a result, the lengths of the first light-emitting control signal line L1 and the third light-emitting control signal line L3 can be made approximately the same, and the resistances of the first light-emitting control signal line L1 and the third light-emitting control signal line L3 can be made approximately the same. Therefore, the following problem can be suppressed: when the same light-emitting control signal is input to the first light-emitting control signal line L1 and the third light-emitting control signal line L3, the current value and voltage level of the light-emitting control signal transmitted in the first light-emitting control signal line L1 are different from those of the light-emitting control signal transmitted in the third light-emitting control signal line L3. This also improves the display quality of the display device 1b. Furthermore, the presence of the third connecting pad 83 suppresses any restriction on the freedom of layout of various wirings on one side of the second surface 2b of the substrate 2. Therefore, the layout of various wirings on one side of the second surface 2b of the substrate 2 becomes easier.

[0052] Furthermore, the third connection pad 83 can be adjacent to the first connection pad 81b located closest to the third edge m3 among the plurality of first connection pads 8. In this configuration, the aforementioned effects are further enhanced.

[0053] The other connection pads mentioned above can be power connection pads connected to the power supply wiring that supplies power to the light-emitting element 6, or connection pads connected to the gate signal line 4.

[0054] like Figure 6 As shown, the display device 1b can have the following structure: the light-emitting elements 6 of the third group 3c are disposed along the end edge 2e3 on the third side m3, and the third connecting pads 83 are located between the light-emitting elements 6 of the third group 3c. In this structure, since the third connecting pads 83 are disposed between the outermost pixel portions 3 on the third side m3 of the substrate 2, the outer frame portion in the third side m3 can be further reduced.

[0055] In display device 1b, it is also possible to... Figure 7As shown, the third connecting pad 83 is larger than the first connecting pad 81. With this structure, the length L3c of the connection portion connecting the third connecting pad 83 and the nearest pixel 3c1 in the third light-emitting control signal line L3 can be shortened, making it closer to L1c. Furthermore, L1c and L3c can be made approximately the same. As a result, the lengths of the first and third light-emitting control signal lines L1 and L3 can be made closer to each other, and the resistances of the first and third light-emitting control signal lines L1 and L3 can be made closer to each other. Therefore, the problem of the current and voltage levels of the light-emitting control signal transmitted in the first and third light-emitting control signal lines L1 differing from those in the third light-emitting control signal line L3 when the same light-emitting control signal is input to both lines can be suppressed.

[0056] To more effectively achieve the aforementioned objective, the length of the third connecting pad 83 along the direction of the third side m3 can be longer than the length of the first connecting pad 81 along the direction of the first side m1. Furthermore, as... Figure 7 As shown, the third connecting pad 83 may also have an extension extending towards the corner between the first side m1 and the third side m3. That is, the third connecting pad 83 may also have an extension 83e extending along the third side m3 towards the first side m1. The width of the extension 83e may be smaller than the width of the main body of the third connecting pad 83. In this structure, it is possible to suppress the width of the outer frame portion in the third side m3 from increasing.

[0057] Figure 12 Is for Figure 7The following is a partial top view illustrating a variation of the display device, showing the wiring structure of the main part. The first connecting pad 81 may also have a length in a direction orthogonal to the direction along the first side m1 that is longer than the length along the direction along the first side m1. In this case, since the first connecting pad 81 is close to the nearest pixel 3 (light-emitting element 6), the length L1c of the connection portion connecting the first connecting pad 81 and the nearest pixel 3 can be further shortened. As a result, the signal transmission path length between the first connecting pad 81 and the nearest pixel 3 is shortened, and signals can be transmitted efficiently from the first connecting pad 81 to the pixel 3. Furthermore, the conductive paste used to form the side wiring 10 easily extends into the depth direction of the first connecting pad 81, resulting in an increased contact area between the side wiring 10 and the first connecting pad 81, and a reduced connection resistance between the side wiring 10 and the first connecting pad 81. The first connecting pad 81 may be rectangular, strip-shaped, elliptical, oblong, or have a long side direction and a short side direction, etc. The length of the direction orthogonal to the direction along the first side m1 in the first connection pad 81 can be more than 1 times and less than 3 times the length of the direction along the first side m1 in the first connection pad 81, but is not limited to this range. Figure 12 The structure of the first connection pad 81 shown can also be used in Figure 3 , Figure 5 , Figure 6 In the display device shown.

[0058] Figure 13 Is for Figure 7 The following is a partial top view illustrating a variation of the display device, showing the wiring structure of the main part. The first connecting pad 81 may have a structure where the length of the portion on the first side m1 (e.g., the edge) is longer than the length of the portion on the side opposite to the first side m1 (e.g., the edge). More specifically, the first connecting pad 81 may have an extension 81e at its end on the first side m1 side, extending in the direction along the first side m1. In this case, the conductive paste used to form the side wiring 10 is effectively pulled into the first connecting pad 81, facilitating its extension into the depth direction of the first connecting pad 81. As a result, the contact area between the side wiring 10 and the first connecting pad 81 increases, and the connection resistance between the side wiring 10 and the first connecting pad 81 decreases. The extension 81e can be disposed between the outermost light-emitting element 6m disposed along the first side m1 on the substrate 2 at the end edge 2e1 on the first side m1 side, and the end of the substrate 2 (outer frame portion). In this case, the conductive paste can be prevented from reaching the outermost light-emitting element 6m. The first connecting pad 81 can be trapezoidal or the like. The length of the portion on the first side m1 of the first connecting pad 81 can be more than one time and about three times the length of the portion on the side opposite to the first side m1 of the first connecting pad 81, but is not limited to this range. Figure 13The structure of the first connection pad 81 shown can also be applied to Figure 3 、 Figure 5 、 Figure 6 the display device shown.

[0059] A structure in which the structure of the first connection pad 81 shown in Figure 12 and the structure of the first connection pad 81 shown in Figure 13 may also be adopted.

[0060] As shown in Figure 2 , in the display device lb, it can be a structure in which the substrate 2 has a first surface 2a on which the plurality of light emitting elements 6 are located, a second surface 2b on the side opposite the first surface 2a, a side surface 2c connecting the first surface 2a and the second surface 2b, and a side surface wiring 10 provided from an end edge portion of the first surface 2a to an end edge portion of the second surface 2b via the side surface 2c, and the third connection pad 83 is connected to the side surface wiring 10. In the case of this structure, the drive portion can be arranged on the side of the second surface 2b of the substrate 2, and the pixel portion 3 and the drive portion are electrically connected via the side surface wiring 10. As a result, since the drive portion that was sometimes arranged on the outer frame portion in the past can be arranged on the side of the second surface 2b, this is advantageous for narrow frame.

[0061] The drive portion can be, for example, an IC, LSI, or the like driving element mounted on the second surface 2b of the substrate 2 by a COG (Chip On Glass) method. Further, the drive portion can be a thin film circuit provided with a thin film transistor (TFT) formed on the second surface 2b of the substrate 2 by a thin film formation method such as a CVD (Chemical Vapor Deposition) method, having a semiconductor layer including LTPS (Low Temperature Poly Silicon). Further, the drive portion can also be a driving element provided in a flexible wiring substrate connected to an external connection terminal on the second surface 2b of the substrate 2. Further, the drive portion can also be an external driving element electrically connected to a wiring of the flexible wiring substrate.

[0062] In the display devices la, lb, as shown in Figure 1 and Figure 2 , it can be a structure in which a power supply connection pad 181 connected to a power supply wiring that supplies a power supply current to the plurality of light emitting elements 6 is provided at an end edge portion 2e2 on the side of the second edge m2. In the case of this structure, since the group of connection pads 8 and the group of power supply connection pads 181 are located on different edges, the wiring configuration is simplified, and this is advantageous for narrow frame.

[0063] The display devices 1a and 1b can have the following structure: each of the multiple pixel units 3 has a rectangular micro-light-emitting diode element with a length of 1 μm or more and 100 μm or less on one side when viewed from above, serving as a light-emitting element. In this case, it is advantageous for high precision.

[0064] The composite display device according to the embodiments of this disclosure is constructed by joining the sides of the aforementioned plurality of display devices 1a (1b) together. Each plurality of display devices 1a (1b) includes a first display device 1a (1b) and a second display device 1a (1b) with the same structure. A portion of the first side of the first display device 1a (1b) adjacent to the first side m1 is joined to a second side of the second display device 1a (1b) opposite to the first side. Furthermore, display device 1a (1b) refers to either display device 1a or display device 1b. The composite display device, with the above structure, achieves the following effects: Reliability is improved because the plurality of connecting pads 8 can be configured to suppress electrical short circuits between them. Furthermore, since a display device 1a (1b) with a narrow bezel is used, the bezel becomes less conspicuous, improving the display quality.

[0065] The specific structure of the display device disclosed herein will be described in detail below. Figure 3 It is a schematic representation Figure 1 A partial top view of the structure of the main part of the display device 1a. Figure 4 Observation from the cut line IV-IV Figure 3 A cross-sectional view of the display device 1a. Figure 8 Observation from the cut surface line VV Figure 3 A cross-sectional view of the display device 1a. Figure 5 It means Figure 1 A partial top view of the wiring structure of the main part of the display device 1a. Figure 6 It means Figure 2 A partial top view of the wiring structure of the main part of the display device 1b. Figure 7 Is for Figure 2 A partial top view of the wiring structure of the main part is shown as a modified example of the display device 1b. Additionally, in Figure 4 as well as Figure 8 In order to simplify the illustration, the circuit structure on the second surface 2b of the substrate 2 is omitted.

[0066] The display devices 1a and 1b of this embodiment can be implemented, for example, using multiple substrates with a narrow outer frame having multiple layers of metal light-shielding layers, which are cut from the back side by laser irradiation of the mother substrate. In this case, a high-output CO2 laser or YAG laser, etc., can be used as the laser for cutting the mother substrate. Laser L( Figure 4The beam diameter is 5 μm to 5 mm. In addition, in the following description, in the case where the display devices 1a and 1b are collectively referred to, the display device 1 is indicated.

[0067] Next, the specific structure of the aforementioned display device 1 provided with the metal light shielding layer will be described. The display device 1 is provided with: a substrate 2; a first metal light shielding layer 31 laminated on the first surface 2a of the substrate 2 on the one side side of the end edge portion W; a first insulating layer 31i laminated on the first metal light shielding layer 31 and the region 2al exposed from the first metal light shielding layer 31 on the first surface 2a; a second metal light shielding layer 32 laminated on the first insulating layer 31i on the region 2a1 not overlapping the first metal light shielding layer 31; and a second insulating layer 32i laminated on the second metal light shielding layer 32 and the first insulating layer 31i on the region 23a overlapping the first metal light shielding layer 31.

[0068] With the above structure, since the first metal light shielding layer 31 and the second metal light shielding layer 32 are provided on the region 2a1 not overlapping the first metal light shielding layer 31, at the time of splitting the mother substrate by laser irradiation from the back surface side at the time of flat panel production, the influence of heat generated at the irradiation portion of the laser on the insulating layer (particularly, the second insulating layer 32i) can be effectively suppressed. As a result, the deposition of the sublimation substance of the insulating layer caused by laser irradiation on the surrounding wiring and the like can be suppressed. In addition, the short circuit of the connection pads 8 transmitting different signals to each other via the end surface, which is the exposed portion of the first metal light shielding layer 31, due to the deviation of the cutting position of the laser can be suppressed. Furthermore, since the metal light shielding layer is split into the first metal light shielding layer 31 and the second metal light shielding layer 32, the metal light shielding layer becomes a structure in which the occurrence of electrostatic discharge is difficult.

[0069] In addition, the display device 1 can be provided with: a pixel portion 3 arranged in a matrix on the first surface 2a of the substrate 2; a power supply circuit 7 on the second surface 2b of the substrate 2; a plurality of first connection pads 8 near the end edge portion W on the first surface 2a of the substrate 2 and electrically connected to the side surface wiring 10; a plurality of back surface side connection pads 80 near the end edge portion W on the second surface 2b of the substrate 2 and electrically connected to the side surface wiring 10; and a plurality of side surface wirings 10. The width of the first metal light shielding layer 31 and the second metal light shielding layer 32 is, for example, about 50 μm to 200 μm.

[0070] The display device 1 further includes: a plurality of first metal light-blocking layers 31 stacked with an interval ΔL1 in a direction in which the first edge ml extends on the end edge portion W on the first surface 2a of the substrate 2 on the first edge ml side; a first insulating layer 31i stacked on the plurality of first metal light-blocking layers 31 and the region 2al exposed between the plurality of first metal light-blocking layers 31 on the first surface 2a of the substrate 2; a plurality of second metal light-blocking layers 32 stacked on the first insulating layer 31i and the region 2al between two first metal light-blocking layers 31 adjacent to each other in the direction in which the first edge ml extends in a plan view; and a second insulating layer 32i stacked on the plurality of second metal light-blocking layers 32 and the region 23a exposed between the plurality of second metal light-blocking layers 32 from the first insulating layer 3li in the plan view.

[0071] The material of the first metal light-blocking layer 31 and the second metal light-blocking layer 32 as the light-blocking layer of the laser L can be aluminum, chromium, molybdenum, or an alloy of these metals. Further, the first metal light-blocking layer 31 and the second metal light-blocking layer 32 can each be a single layer or a stacked structure in which a plurality of layers are stacked. In the case where the material of the first and second metal light-blocking layers 31, 32 is aluminum having a high reflectance, a transparent insulating layer can be provided on the laser L irradiation side of the first and second metal light-blocking layers 31, 32. In this case, the laser L is reflected without a decrease in reflectance by the first and second metal light-blocking layers 31, 32, and heat absorption is reduced by the transparent insulating layer. As a result, the laser L is efficiently reflected to the outside of the second surface 2b side of the substrate 2 with a reduction in heat absorption. Therefore, the effect of reducing heat damage to the second insulating layer 32i and the organic insulating layers 24, 26, and the like is increased.

[0072] Further, the material of the first metal light-blocking layer 31 and the second metal light-blocking layer 32 can be molybdenum or the like. Molybdenum efficiently absorbs laser light and transmits heat, and thus the intensity of reflected light can be reduced, and the temperature increase of the display device 1 can be suppressed. That is, the effect of reducing heat damage caused by secondary reflection and absorption of reflected light by the first and second metal light-blocking layers 31, 32 can be increased.

[0073] Further, the first metal light-blocking layer 31 and the second metal light-blocking layer 32 can have a structure including Mo / Al / Mo, MoNd / AlNd / MoNd, or the like. Here, "Mo / Al / Mo" indicates a stacked structure in which an Al layer is stacked on a Mo layer and a Mo layer is stacked on the Al layer. Further, "MoNd" indicates an alloy of Mo and Nd.

[0074] Further, the material of the first metal light-blocking layer 31 and the second metal light-blocking layer 32 can be chromium oxide that appears black. That is, it can be a layer that absorbs the laser L to attenuate it.

[0075] Further, the display device 1 can be structured as shown in Figure 3 As shown in FIG. 6, the first metal light-shielding layer 31 has a plurality of first metal light-shielding layers 31 stacked in the direction parallel to one side (for example, the first side ml) with each first metal light-shielding layer 31 spaced apart from each other at the end edge portion W, and the second metal light-shielding layer 32 is stacked on the region 2al between the adjacent first metal light-shielding layers 31 on the first insulating layer 3li. Further, the region 2al is also a portion not overlapping the first metal light-shielding layer 31. In this case, the first metal light-shielding layer 31 and the second metal light-shielding layer 32 are more finely divided and each has a smaller area, and thus, the metal light-shielding layer is structured to be more difficult to generate electrostatic discharge.

[0076] The first metal light-shielding layer 31 and the second metal light-shielding layer 32 can be in a row in plan view. In this case, light (laser light) incident from the side of the second surface 2b of the substrate 2 can be more suppressed from reaching the second insulating layer 32i. As a result, the second insulating layer 32i can be more effectively suppressed from being affected by the heat of the laser light.

[0077] The second metal light-shielding layer 32 can have an overlapping portion (overlapping portion) LW overlapping the first metal light-shielding layer 31 in plan view. In this case, light (laser light) incident from the side of the second surface 2b of the substrate 2 can be further suppressed from reaching the second insulating layer 32i. As a result, the second insulating layer 32i can be further effectively suppressed from being affected by the heat of the laser light. The length of the overlapping portion LW can be about 5 μm to 500 μm.

[0078] Further, the overlapping portion LW can have a length such that diffracted light diffracted at the end of the first metal light-shielding layer 31 from light (laser light) incident from the side of the second surface 2b of the substrate 2 does not reach the second insulating layer 32i. In this case, the same effect as described above is also obtained. The length of the overlapping portion LW in this case is about 20 μm to 700 μm.

[0079] The first metal light-blocking layer 31 and the second metal light-blocking layer 32 can be a structure having light reflectivity. In this case, since light (laser light) incident from the side of the second surface 2b of the substrate 2 is reflected at the first metal light-blocking layer 31 and the second metal light-blocking layer 32, the second insulating layer 32i can be further effectively suppressed from being affected by heat of the laser light. The first metal light-blocking layer 31 and the second metal light-blocking layer 32 can contain, for example, a metal material, an alloy material, or the like having high light reflectivity of visible light. As the metal material, there are aluminum (Al), silver (Ag), gold (Au), chromium (Cr), nickel (Ni), platinum (Pt), tin (Sn), and the like. Further, as the alloy material, there are aluminum alloys having aluminum as a main component, such as duralumin (Al-Cu alloy, Al-Cu-Mg alloy, Al-Zn-Mg-Cu alloy), and the like. As the light reflectivity of these materials, aluminum is about 90% to 95%, silver is about 93%, gold is about 60% to 70%, chromium is about 60% to 70%, nickel is about 60% to 70%, platinum is about 60% to 70%, tin is about 60% to 70%, and the aluminum alloy is about 80% to 85%. Thus, as a suitable material for the first metal light-blocking layer 31 and the second metal light-blocking layer 32 having light reflectivity, there are aluminum, silver, gold, the aluminum alloy, and the like.

[0080] The first metal light-blocking layer 31 and the second metal light-blocking layer 32 can also be a structure having light scattering properties. In this case, generally, the arithmetic surface roughness of the surface of the thin film or the surface of the substrate becomes an optical mirror surface using about one-tenth of the wavelength. Thus, if the light of the wavelength of 550 nm, which is the highest sensitivity of the human eye, the surface having an arithmetic surface roughness of 55 nm or less easily becomes an optical mirror surface. Thus, the surface having an arithmetic surface roughness of 55 nm or more easily becomes a light scattering surface, and thus each surface of the first metal light-blocking layer 31 and the second metal light-blocking layer 32 having light scattering properties can have an arithmetic surface roughness of about 55 nm to 10 μm. Suitably, it can be about μLm to 10 μm, and more suitably, it can be about 2 μm to 7 μm.

[0081] The first insulating layer 31i can be a structure including light-scattering particles. In this case, light (laser light) incident from the second surface 2b side of the substrate 2 is scattered by the light-scattering particles contained in the first insulating layer 31i, and the second insulating layer 32i can be effectively inhibited from being affected by the heat of the laser light. The light-scattering particles include, for example, a metal material, an alloy material, a glass material, a ceramic material, a metal oxide material, and the like. As the metal material, there are aluminum (Al), silver (Ag), gold (Au), chromium (Cr), nickel (Ni), platinum (Pt), tin (Sn), and the like. Further, as the alloy material, there are aluminum alloys in which aluminum is a main component, such as duralumin (Al-Cu alloy, Al-Cu-Mg alloy, Al-Zn-Mg-Cu alloy), and the like. As the glass material, there are borosilicate glass, crystalline glass, quartz, soda glass, and the like. As the ceramic material, there are alumina, aluminum nitride, silicon nitride, and the like. As the metal oxide material, there are titanium oxide and the like. In the case where the light-scattering particles contain a transparent material such as a glass material, a metal oxide material, and the like, laser light incident from the second surface 2b side of the substrate 2 is scattered and refracted, and thus it is difficult for the laser light to reach the second insulating layer 32i side. Further, in the case where the light-scattering particles have light reflectivity such as a metallic luster of a metal material, an alloy material, and the like, laser light incident from the second surface 2b side of the substrate 2 is reflected and scattered, and thus it is difficult for the laser light to reach the second insulating layer 32i side.

[0082] The average particle diameter of the light-scattering particles can be about 55 nm to 10 μm. Suitably, it can be about 1 μm to 10 μm, and more suitably, it can be about 2 μm to 7 μm.

[0083] The first insulating layer 31i can be a structure including an inorganic material such as silicon oxide (SiO2) and silicon nitride (Si3N4). In this case, the laser light resistance of the first insulating layer 31i, which is incident before the second insulating layer 32i from the second surface 2b side of the substrate 2, is improved.

[0084] The second insulating layer 32i can be a structure including an organic material such as an acrylic resin and a polycarbonate resin. In this case, the second insulating layer 32i, which is difficult to be affected by the heat of laser light incident from the second surface 2b side of the substrate 2, can constitute a planarization layer or the like having a thick thickness.

[0085] Further, the second insulating layer 32i can be a light-blocking layer including a black-colored resin, so-called black matrix, and the like. In this case, in the case where the display device 1 is used to manufacture a display device, the light-blocking layer becomes a background color of black, and the contrast of a display image is improved.

[0086] The side surface wiring 10 can be a structure in which a side surface wiring 10 is provided from the end edge portion W of the first surface 2a of the substrate 2 to the side surface 2c of the substrate 2 to the side surface wiring 10 on the side of the second surface 2b, and the side surface wiring 10 is positioned so as to overlap the first metal light shielding layer 31 and / or the second metal light shielding layer 32. In this case, short-circuiting of adjacent side surface wirings 10 via the exposed portion of the first metal light shielding layer 31 and / or the exposed portion of the second metal light shielding layer 32 can be suppressed. The side surface wiring 10 can be formed by a method such as a heating method, a photocuring method in which curing is performed by irradiation with light such as ultraviolet light, or a photocuring heating method, after a conductive paste containing conductive particles such as Ag, Cu, Al, stainless steel, or the like, an uncured resin component, an alcohol solvent, water, or the like is applied to a desired portion from the first surface 2a to the side surface 2c and the second surface 2b of the substrate 2. The side surface wiring 10 can also be formed by a thin film forming method such as plating, vapor deposition, or CVD (Chemical Vapor Deposition). Furthermore, a groove can be formed in advance in a portion of the first surface 2a, the side surface 2c, and the second surface 2b of the substrate 2 where the side surface wiring 10 is to be formed. Thus, the conductive paste that becomes the side surface wiring 10 is easily disposed in a desired portion of the substrate 2.

[0087] The first metal light shielding layer 31 and the second metal light shielding layer 32 can also be configured so as to be electrically floating (in a floating state). That is, the first metal light shielding layer 31 and the second metal light shielding layer 32 can be in a state of being not connected to a specific potential portion such as an anode potential portion or a cathode potential portion. In this case, degradation due to electrical corrosion caused by a potential gradient in the first metal light shielding layer 31 and the second metal light shielding layer 32 from the end portion on the opposite side of the connection portion to the specific potential portion can be prevented.

[0088] Furthermore, the first metal light shielding layer 31 and the second metal light shielding layer 32 can be disposed around the entire circumference of the substrate 2. For example, in the case where the substrate 2 is rectangular, if all the edges (four edges) are edges that are cut by laser, the first metal light shielding layer 31 and the second metal light shielding layer 32 can be disposed on all the edges. Alternatively, in the case where the substrate 2 has edges that are cut by laser and edges that are not cut by laser, the first metal light shielding layer 31 and the second metal light shielding layer 32 can be disposed at least on the edges that are cut by laser.

[0089] The first insulating layer 3li contains an inorganic material. The second insulating layer 32i contains an organic material. In the case where a wiring layer of the light emitting element 6, a TFT that drives and controls the light emitting element 6, a gate signal line 4, a source signal line 5, and the like that connect the light emitting element 6 and the TFT are provided on the first surface 2a of the substrate 2, at least one of the first metal light shielding layer 31 and the second metal light shielding layer 32 can be a structure that contains the same material as the wiring layer. In this case, the number of processes can be reduced.

[0090] Figure 9 It is a schematic representation Figure 1 The block circuit diagram of the circuit structure on the first surface 2a side of the display device shown is as follows. Figure 10 This is a block circuit diagram schematically showing the circuit structure on the second surface 2b side of the display device. The substrate 2 is, for example, a transparent or opaque glass substrate, a plastic substrate, a ceramic substrate, etc. The substrate 2 has a third surface (side surface) 2c connecting the first surface 2a and the second surface 2b. The substrate 2 has a shape having at least a first side m1 and an adjacent second side m2. For example, the shape of the substrate 2 can be a triangular plate, a rectangular plate, a parallelogram plate, a trapezoidal plate, a hexagonal plate, etc., or other shapes. When the shape of the substrate 2 is a triangular plate, a rectangular plate, a hexagonal plate, etc., it is easy to lay multiple display devices 1 flat to create a composite and large display device (hereinafter also referred to as a multi-display). In this embodiment, for example... Figure 1 , 2 As shown, substrate 2 has a rectangular plate shape. Alternatively, substrate 2 may have a third side m3 adjacent to the first side m1 and opposite the second side m2. In this case, for example, the shape of substrate 2 may be a rectangular plate, a parallelogram plate, a trapezoidal plate, a hexagonal plate, or other shapes. The second side m2 and the opposite third side m3 may be parallel to each other, but they may not be perfectly parallel.

[0091] Pixel units 3 are arranged in a matrix at a given spacing on the first surface 2a of substrate 2. The pixel units 3 are arranged corresponding to the intersections of multiple gate signal lines 4 and multiple source signal lines 5, and each pixel unit 3 has a light-emitting element 6. The multiple gate signal lines 4 are arranged along a given direction (is... Figure 9 The multiple source signal lines 5 are arranged in a left-right direction (e.g., row direction). They intersect with the multiple gate signal lines 4 in a direction intersecting a given direction (e.g., column direction). The multiple pixel portions 3 are correspondingly arranged at the intersections of the multiple gate signal lines 4 and the multiple source signal lines 5. For example, as... Figure 9 As shown, multiple pixel units 3 are arranged in a matrix with a given pixel spacing.

[0092] Each of the plurality of pixel portions 3 has a light emitting element 6 and an electrode pad 62. The light emitting element 6 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 6. The light emitting element 6 can be a micro LED element. In the case where the light emitting element 6 is a micro LED element, the light emitting element 6 can have a rectangular plan view shape with a length of one side of 1 μm or more and 100 μm or less, or 3 μm or more and 10 μm or less, in a state where the light emitting element 6 is disposed on the first surface 2a.

[0093] The light emitting element 6 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 6 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.

[0094] Each pixel portion 3 can have a plurality of light emitting elements 6, a plurality of anode pads 62a, and a single or a plurality of cathode pads 62b. The plurality of anode pads 62a are electrically connected to a plurality of anode terminals of the plurality of light emitting elements 6, respectively, and the single or the plurality of cathode pads 62b are electrically connected to a plurality of cathode terminals of the plurality of light emitting elements 6. In the case where the cathode pad 62b is single, the cathode pad 62b can be common to the plurality of light emitting elements 6. The plurality of light emitting elements 6 can be a red light emitting element 61R, a green light emitting element 61G, and a blue light emitting element 61B. In this case, each pixel portion 3 can perform color gradation display. Each pixel portion 3 can have, instead of the red light emitting element 61R, an orange light emitting element, a red-orange light emitting element, a red-purple light emitting element, or a purple light emitting element. Further, each pixel portion 3 can have, instead of the green light emitting element 61G, a yellow-green light emitting element.

[0095] For example, as Figure 10As shown, the power supply circuit 7, serving as the power supply unit, is disposed on the second surface 2b. The power supply circuit 7 generates a first power supply voltage VDD and a second power supply voltage VSS to supply to the plurality of pixel units 3. The power supply circuit 7 has 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 approximately 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 approximately 0V to 3V. The power supply circuit 7 can be constructed, for example, from a flexible circuit board (FPC). The power supply unit can be a circuit module incorporating semiconductor components such as ICs and LSIs for power supply voltage control. Furthermore, the power supply unit can include: the power supply circuit 7; and a control element composed of an IC chip for generating control signals for controlling the luminescence, non-luminescence, and luminescence intensity of the light-emitting element 6. The control element can be included as a control unit within the power supply circuit 7.

[0096] Furthermore, the drive circuit section 13 is disposed on the second surface 2b. The drive circuit section 13 is electrically connected to the source signal line 5 disposed on the first surface 2a via the second source signal line 17 disposed on the second surface 2b. The drive circuit section 13 and the power supply circuit 7 may also be electrically connected for synchronizing their operation.

[0097] For example, Figure 9 As shown, the power connection pads 108 on the surface side are disposed on the edge portion W of the second side m2 on the first surface 2a. The edge portion W is the edge portion along the second side m2, and is a portion on the first surface 2a with a width of about 10μm to 500μm from the second side m2 toward the center of the first surface 2a, but is not limited to this width value. The power connection pads 108 have a plurality of first power connection pads 181 and a plurality of second power connection pads 182. The first power connection pads 181 are connection pads for supplying a first power supply voltage VDD to the plurality of pixel units 3, and the second power connection pads 182 are connection pads for supplying a second power supply voltage VSS to the plurality of pixel units 3. The first power connection pad 181 and the second power connection pad 182 are rectangular with a side length of approximately 50μm to 500μm, preferably 70μm to 300μm. However, the side length is not limited to these values, and the shape can also be a polygonal shape, trapezoidal shape, circular shape, elliptical shape, or other shapes. The same structure can be used for the wiring pads described below.

[0098] For example, Figure 9As shown, the display device 1 has a first winding wiring 11a and a second winding wiring 11b. The first winding wiring 11a and the second winding wiring 11b are located on the first surface 2a. The first winding wiring 11a and the second winding wiring 11b include, for example, Mo / Al / Mo, MoNd / AlNd / MoNd, etc. Here, "Mo / Al / Mo" indicates 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 applies to other structures. The first winding wiring 11a connects the anode terminal of the light-emitting element 6 to a plurality of first power connection pads 181. The second winding wiring 11b connects the cathode terminal of the light-emitting element 6 to a plurality of second power connection pads 182.

[0099] The first lead-in wiring 11a and the second lead-in wiring 11b can be planar wiring patterns. In this case, the first lead-in wiring 11a and the second lead-in wiring 11b are electrically insulated from each other by an insulating layer (not shown) disposed between them. The anode pad 62a of the electrode pad 62 can be formed as part of the first lead-in wiring 11a.

[0100] like Figure 10 As shown, the power connection pad 9 on the back side is located on the second surface 2b. The power connection pad 9 can be, for example, disposed on the edge portion of the second side m2. This edge portion can have the same structure as the edge portion W described above. The power connection pad 9 has a plurality of third power connection pads 91 and a plurality of fourth power connection pads 92. The third power connection pads 91 are connection pads for supplying a first power supply voltage VDD to the plurality of pixel units 3, and the fourth power connection pads 92 are connection pads for supplying a second power supply voltage VSS to the plurality of pixel units 3.

[0101] The display device 1 has the following structure: the number of multiple first power connection pads 181 is equal to the number of multiple third power connection pads 91, and the number of multiple second power connection pads 182 is equal to the number of multiple fourth power connection pads 92. The multiple first power connection pads 181 and the multiple third power connection pads 91 can overlap when viewed from above, i.e., when viewed from a direction orthogonal to the first surface 2a. The multiple second power connection pads 182 and the multiple fourth power connection pads 92 can overlap when viewed from above.

[0102] The display device 1 has a third lead-wound wire 12. The third lead-wound wire 12 is located on the second surface 2b. The third lead-wound wire 12 includes, for example, Mo / Al / Mo, MoNd / AlNd / MoNd, Ag, etc. Figure 10 As shown, the third lead-in wiring 12 connects the VDD terminal of the power supply circuit 7 to a plurality of third power connection pads 91, and connects the VSS terminal of the power supply circuit 7 to a plurality of fourth power connection pads 92.

[0103] The plurality of side surface wirings 10 are arranged from the first surface 2a to the second surface 2b via the side surface, i.e., the third surface 2c of the substrate 2. In the present embodiment, for example, as shown in Figure 8 , the plurality of side surface wirings 10 are arranged from the first surface 2a to the third surface 2c and the second surface 2b. The plurality of side surface wirings 10 connect the plurality of first power supply connection pads 181 and the plurality of third power supply connection pads 91, respectively. The plurality of side surface wirings 10 connect the plurality of second power supply connection pads 182 and the plurality of fourth power supply connection pads 92, respectively.

[0104] The display device 1 can also be a structure having a plurality of through conductors that penetrate from the first surface 2a to the second surface 2b instead of the plurality of side surface wirings 10. Further, it can also be a structure having the plurality of side surface wirings 10 and having the plurality of through conductors. The display device 1 of the present embodiment can suitably be a structure having at least the plurality of side surface wirings 10.

[0105] The display device 1 has a gate wiring that is arranged from the first surface 2a to the second surface 2b, connecting the plurality of gate signal lines 4 and the control section of the power supply circuit 7. For example, as shown in Figure 9 10 , the gate wiring has a fifth connection pad 18, a sixth connection pad 19, a first gate wiring 20, a second gate wiring 21, and a third gate wiring 22. The third gate wiring 22 is formed as a side surface wiring.

[0106] For example, as shown in Figure 9 , the fifth connection pad 18 is arranged at an end edge portion on the second side m2 of the first surface 2a. For example, as shown in Figure 10 , the sixth connection pad 19 is arranged at an end edge portion on the second side m2 of the second surface 2b. The fifth connection pad 18 and the sixth connection pad 19 can overlap in plan view. For example, as shown in Figure 9 , the first gate wiring 20 is arranged on the first surface 2a, connecting the plurality of gate signal lines 4 and the fifth connection pad 18. For example, as shown in Figure 10 , the second gate wiring 21 is arranged on the second surface 2b, connecting the control section of the power supply circuit 7 and the sixth connection pad 19. For example, as shown in Figure 9 10 , the third gate wiring 22 is arranged from the first surface 2a to the third surface 2c and the second surface 2b, connecting the fifth connection pad 18 and the sixth connection pad 19.

[0107] ​​The bonding pad 8 (e.g., the first bonding pad 81) and the corresponding seventh bonding pad 80 on the back side contain conductive material. The first bonding pad 8 and the seventh bonding pad 80 may contain a single metal layer or may be formed by stacking multiple metal layers. The first bonding pad 8 and the seventh bonding pad 80 may contain, for example, Al, Al / Ti, Ti / Al / Ti, Mo, Mo / Al / Mo, MoNd / AlNd / MoNd, Cu, Cr, Ni, Ag, etc.

[0108] like Figure 8 As shown, the connection pad 8 can be a structure formed by stacking two conductor layers 8a1 and 8a2. The conductor layer 8a1 can contain Al, Al / Ti, Ti / Al / Ti, Mo, Mo / Al / Mo, MoNd / AlNd / MoNd, Cu, Cr, Ni, Ag, etc., and the conductor layer 8a2 on the conductor layer 8a1 can contain a transparent conductive layer containing ITO (Indium Tin Oxide), IZO (Indium Zinc Oxide), etc. In addition, insulating layers 25 and 26 can be disposed at the inner end of the first surface 2a in the connection pad 8. This can suppress short circuits between the connection pad 8 and the wiring conductor disposed on the inner side of the first surface 2a. The insulating layers 25 and 26 contain, for example, polymer materials such as SiO2, Si3N4, and acrylic resin. The surface of the seventh connection pad 80 can be covered with a transparent conductive layer containing ITO, IZO, etc.

[0109] Each pixel unit 3 includes on the substrate 2: a first thin film transistor (TFT) serving as a switching element for inputting light emission signals to the light emission element 6; and a second thin film transistor serving as a driving element for driving the light emission element 6 with current based on the potential difference (light emission signal) between a positive voltage (anode voltage: approximately 10V to 15V) and a negative voltage (cathode voltage: approximately 0V to 3V) corresponding to the level (voltage) of the light emission control signal (the signal transmitted in the image signal line SL).

[0110] The first and second TFTs, for example, have a semiconductor film including amorphous silicon (a-Si), low-temperature polysilicon (LTPS), or the like, and have a structure with three terminals of a gate electrode, a source electrode, and a drain electrode. Further, the first and second TFTs can adopt a structure in which both are n-channel TFTs, both are p-channel TFTs, or one is an n-channel TFT and the other is a p-channel TFT. Further, the first and second TFTs function as switching elements (gate transfer elements) that flow a current between the source electrode and the drain electrode of the semiconductor film (channel) by applying a voltage (2.5 V to 3.5 V or the like) of a given potential to the gate electrode. The substrate 2 includes a glass substrate, and in a case where the driving circuit is configured using a TFT having a semiconductor film including LTPS, the TFT can be formed directly on the substrate 2 by a thin film formation method such as a CVD (Chemical Vapor Deposition) method.

[0111] Figure 14 is a partial plan view of a main part showing an embodiment of a composite display device of the present disclosure. As shown in Figure 14 A plurality of display devices 1 of the present disclosure can be used to configure a composite display device 100. The composite display device 100 is configured by joining side surfaces of a plurality of display devices 1 to each other. The plurality of display devices 1 include a first display device 1A and a second display device 1B, and a first side surface 2c1 in the first display device 1A adjacent to the first side m1 is joined to a second side surface 2c2 in the second display device 1B opposite to the first side surface 2c1. The joining material 90 that joins the first side surface 2c1 of the first display device 1A to the second side surface 2c2 of the second display device 1B can be a resin adhesive. The resin adhesive, for example, includes an epoxy resin, a polyamide resin, a resin in which an epoxy resin and a polyamide resin are mixed, an acrylic resin, a silicone resin, a urethane resin, or the like, which is a photocurable or thermosetting resin material. The resin adhesive can be a black resin material in which a black inorganic pigment is mixed in a resin material. In this case, since the joining portion (tiled portion) of the first display device and the second display device is not conspicuous, it is easy to maintain continuity of a display image. The inorganic pigment can be a carbon-based pigment such as carbon black, a nitride-based pigment such as titanium black, a metal oxide-based pigment such as Cr-Fe-Co-based, Cu-Co-Mn (manganese)-based, Fe-Co-Mn-based, Fe-Co-Ni-Cr-based, or the like.

[0112] The composite display device 100 can also be configured by combining three or more display devices 1. In addition, the composite display device 100 can have a base substrate on which a plurality of display devices 1 are fixed via a fixing member. The fixing member can include a mechanical fixing element such as a screw, a clip, or a fitting member, or a chemical fixing element such as an adhesive. In addition, the fixing member can be a frame that includes a rim portion of the substrate 2 of the display device 1, and the frame is fixed to the base substrate by a mechanical fixing element or a chemical fixing element.

[0113] The bonding material can be black and have a concave-convex structure that absorbs incident light on the surface. For example, the bonding material can be a black resin formed by mixing a black pigment such as carbon black in a base material such as silicone resin, and a concave-convex structure having an arithmetic mean roughness of about 10 μm to 50 μm, preferably about 20 μm to 30 μm, is formed on the surface of the black resin by a transfer method or the like. In this case, the light absorption property of the bonding material is particularly improved.

[0114] According to the present embodiment, in the case where a plurality of display devices 1 are tiled to produce a composite display device, the surface side and the back side of each display device 1 are electrically connected by the side wiring 10 including Ag or the like. In the case where a single-layered metal light shielding layer that shields laser light is disposed at the formation site of the side wiring 10 of the substrate 2 as in the past, the adjacent side wirings 10 can be short-circuited via the metal light shielding layer, but in the present embodiment, since the metal light shielding layer is separated into the first metal light shielding layer 31 and the second metal light shielding layer 32 that are located at different positions in the stacking direction, the adjacent side wirings 10 can be prevented from being short-circuited via the first metal light shielding layer 31. In addition, in the present embodiment, in the case where the first metal light shielding layer 31 and the second metal light shielding layer 32 have the overlapping portion Lw so as to be aligned in a plan view, even if laser light is irradiated from the side of the second surface 2b of the substrate 2, the second insulating layer 32i or the like can be effectively suppressed from being affected by the heat of the laser light. In addition, in the case where the first metal light shielding layer 31 and the second metal light shielding layer 32 are electrically floating (levitation state), deterioration due to electrical corrosion can be prevented from occurring in the first metal light shielding layer 31 and the second metal light shielding layer 32. In addition, since the metal light shielding layer is divided into the first metal light shielding layer 31 and the second metal light shielding layer 32, the metal light shielding layer becomes a structure in which electrostatic discharge is difficult to occur.

[0115] In addition, since the metal light shielding layer is divided into the first metal light shielding layer 31 and the second metal light shielding layer 32, the metal light shielding layer becomes a structure in which electrostatic discharge is difficult to occur. Figure 4As shown, since the first metal light-shielding layer 31 and the second metal light-shielding layer 32 are positioned not only on the second insulating layer 32i but also on the side closer to the laser L than the organic layers, i.e., the insulating layers (organic insulating layers) 24, 26, which are planarization layers or the like and are thicker than the first insulating layer 21, the influence of the heat of the laser L on the second insulating layer 32i and the influence of the heat of the laser L on the organic insulating layers 24, 26 can be suppressed. That is, the organic insulating layers 24, 26 can be suppressed from subliming due to the heat of the laser L, solidifying thereafter, and adhering to the wiring or the like on the first surface 2a as a foreign matter.

[0116] The thickness of each of the first metal light-shielding layer 31 and the second metal light-shielding layer 32 is about 50 nm to 1 μm, but the thickness of the first metal light-shielding layer 31 can be made thicker than the thickness of the second metal light-shielding layer 32. In this case, the first metal light-shielding layer 31 on the side closer to the laser L efficiently absorbs the heat of the laser, and the second metal light-shielding layer 32 can be less affected by the heat of the laser. The thickness of the first metal light-shielding layer 31 can be set to more than one time and about five times or less the thickness of the second metal light-shielding layer 32, but is not limited to a high value. If it is more than five times, there is a tendency to hinder the thinning of the display device 1.

[0117] The embodiments of the present disclosure are described in detail above, and the present disclosure is not limited to the above-described embodiments, but various changes, modifications, and the like can be made within the scope of the gist of the present disclosure. All or a part of each of the above-described embodiments can be combined as appropriate without contradiction, as a matter of course.

[0118] According to the display device of the present disclosure, for a plurality of connection pads that are difficult to be miniaturized, it is possible to suppress the occurrence of an electrical short circuit therebetween and the enlargement of the frame portion, and it is possible to arrange on a substrate. Furthermore, it is possible to further reduce the frame portion to arrange the plurality of connection pads on the substrate.

[0119] Industrial applicability

[0120] The display device of the present disclosure can be configured as a light emitting display device such as an LED display device, an organic EL display device, and a liquid crystal display device. In addition, the display device of the present disclosure can be used in various electronic devices. As the electronic devices, there are a large-sized display device (multi-display), a car route guidance system (navigation system), a ship route guidance system, an aircraft route guidance system, a smartphone terminal, a portable telephone, a tablet terminal, a personal digital assistant (PDA), a video camera, a digital still camera, an electronic notebook, an electronic book, an electronic dictionary, a personal computer, a terminal device of a copying machine, a game device, a television, a product display label, a price display label, an industrial programmable display device, a car audio, a digital audio player, a facsimile, a printer, an automatic teller machine (ATM), a vending machine, a head-up display (HMD), a digital display watch, a smart watch, and the like.

[0121] The present disclosure can be implemented in other various forms, without departing from the spirit or essential characteristics thereof. Therefore, the foregoing embodiments are merely illustrative, and all matters should be construed in an illustrative way. Further, the scope of the invention is given by the appended claims rather than the description of the specification. Moreover, it is intended to cover all changes and modifications of the application, which are within the scope of the claims.

[0122] Explanation of Symbols

[0123] 1, 1a, 1b Display device

[0124] 2 Substrate

[0125] 2a First surface

[0126] 2b Second surface

[0127] 2c Third surface (side surface)

[0128] 3 Pixel portion

[0129] 6 Light emitting element

[0130] 8 Connection pad

[0131] 81 First connection pad

[0132] 82 Second connection pad

[0133] 83 Third connection pad

[0134] 10 Side surface wiring

[0135] L1 First light emission control signal line

[0136] L2 Second light emission control signal line

[0137] L3 Third light emission control signal line

[0138] m1 First side m2 Second side

[0139] m2 2nd side

[0140] m3 3rd side.

Claims

1. A display device comprising: a substrate having a first side and a second side adjacent to the first side; a plurality of light emitting elements on the substrate; and a plurality of connection pads on the substrate at an end portion on the first side and an end portion on the second side, each of which is connected to a plurality of light emission control signal lines, the plurality of connection pads including: a plurality of first connection pads on the end portion on the first side along the first side, each of which is connected to a first light emission control signal line that controls light emission / non-light emission of each of a first group of the light emitting elements among the plurality of light emitting elements; and a second connection pad on the end portion on the second side, which is connected to a second light emission control signal line that controls light emission / non-light emission of a second group of the light emitting elements among the plurality of light emitting elements, the end portion on the second side has other connection pads connected to wirings other than the second light emission control signal line, and the second connection pad is located closer to the first side than the other connection pads.

2. The display device according to claim 1, wherein the plurality of light emitting elements include a plurality of outermost light emitting elements on the end portion on the first side along the first side, and the first connection pads are located between the plurality of outermost light emitting elements.

3. The display device according to claim 1 or 2, wherein the second group of the light emitting elements are arranged along the end portion on the second side, and the second connection pad is located between the second group of the light emitting elements. a plurality of light emission control signal lines on the substrate, which control light emission / non-light emission of the light emitting elements; 4. The display device according to claim 1 or 2, wherein the second connection pad is larger than the first connection pad.

5. The display device according to claim 4, wherein the second connection pad has a main portion and an extension portion extending from the main portion toward the first side along the second side, and a width of the extension portion is smaller than a width of the main portion.

6. The display device according to claim 1 or 2, wherein the substrate has a first surface on a side where the plurality of light emitting elements are located, a second surface on a side opposite to the first surface, a side surface connecting the first surface and the second surface, and a side surface wiring provided from an end portion of the first surface to an end portion of the second surface via the side surface, and the first connection pads and the second connection pad are each connected to the side surface wiring.

7. The display device according to claim 1 or 2, wherein the substrate has a third side adjacent to the first side and opposite to the second side, and the display device comprises: a third connection pad on an end portion on the third side of the substrate, which is connected to a third light emission control signal line that controls light emission / non-light emission of a third group of the light emitting elements among the plurality of light emitting elements.

8. The display device according to claim 7, wherein the end portion on the third side of the substrate has other connection pads connected to wirings other than the third light emission control signal line. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The third connection pad is located closer to the first side than the other connection pads.

9. The display device according to claim 7, wherein The light emitting elements of the third group are arranged along an end edge portion of the third side, The third connection pad is located between the light emitting elements of the third group.

10. The display device according to claim 7, wherein The third connection pad is larger than the first connection pad.

11. The display device according to claim 7, wherein The third connection pad has a main portion and an extension portion extending toward the first side along the third side, The extension portion is narrower than the main portion.

12. The display device according to claim 7, wherein The substrate has a first surface on a side where the plurality of light emitting elements are located, a second surface on a side opposite to the first surface, a side surface connecting the first surface and the second surface, and a side surface wiring provided from an end edge portion of the first surface to an end edge portion of the second surface via the side surface, The third connection pad is connected to the side surface wiring.

13. The display device according to claim 12, wherein The substrate has a driving portion electrically connected to the side surface wiring on the second surface side.

14. The display device according to claim 1 or 2, wherein A power supply connection pad connected to a power supply wiring that supplies a power supply current to the plurality of light emitting elements is arranged at an end edge portion on the second side.

15. The display device according to claim 1 or 2, wherein The light emitting elements are micro light emitting diode elements.

16. A composite display device, The plurality of display devices according to any one of claims 1 to 15 are provided, The composite display device is configured by joining side surfaces of the plurality of display devices to each other, The plurality of display devices include a first display device and a second display device, A first side surface adjacent to the first side in the first display device and a second side surface opposite to the first side in the second display device are joined.

Images