JP7638091B2 - Display device and manufacturing method thereof - Google Patents

Description

The present invention relates to a display device and a manufacturing method thereof.

For example, organic EL display devices (organic EL displays) that use organic electroluminescence (EL) elements are highly luminous and self-luminous, can be driven at a low DC voltage, have high response speeds, and emit light from a solid organic film. As a result, they have excellent display performance and can be made thin, lightweight, and consume less power. For these reasons, they are expected to replace liquid crystal display devices in the future (see, for example, Patent Document 1 below).

Specifically, an organic EL display device has a display panel including a display area in which a plurality of pixels are arranged in a matrix on a surface. The display panel includes a plurality of scanning lines (gate lines), a plurality of signal lines (data lines), and a plurality of power lines (power lines) arranged in the horizontal and vertical directions on the surface of the display area, and a pixel circuit that constitutes the above-mentioned pixels is provided in each area partitioned by the plurality of scanning lines and the plurality of signal lines.

The display panel has a pixel circuit that includes an organic EL element, which is a light-emitting element, a capacitor, which is a storage capacitance, and two thin film transistor (TFT) elements, which are switching elements. In the display panel, the potential (image data) of the signal line is stored in the storage capacitance connected to the signal line via the selection TFT element through the switching operation of the selection TFT element connected to the scan line. In addition, depending on the potential of the storage capacitance, a drive current flows through the organic EL element connected to the power line via the drive TFT element. This makes it possible to cause the organic EL element to emit light (light up).

The display panel also has a peripheral area called a bezel (frame) that surrounds the periphery of the display area. In the peripheral area, a number of connection parts corresponding to a number of scanning lines and a number of signal lines that are drawn out to the outside of the display area are arranged in the horizontal and vertical directions of the peripheral area. The multiple scanning lines and multiple signal lines are electrically connected to an external drive circuit (driver) via a flexible printed circuit board (FPC) that is connected to the multiple connection parts.

However, in the conventional display devices described above, the wiring resistance increases according to the distance of the wiring routed between the pixel circuit and the drive circuit, which causes the problem of signal delay between pixels. Furthermore, the larger the panel size, the longer the wiring distance described above becomes, and this problem, such as the occurrence of variation in signal delay, becomes more pronounced. Furthermore, the more pixels there are, the longer it takes to write image data to each pixel, so it is necessary to further suppress the occurrence of the above-mentioned signal delay and its variation.

In order to solve these problems, it is effective to increase the thickness of the wiring and reduce the wiring resistance. However, with the metal materials commonly used for wiring, there is an issue that the thicker the wiring, the more likely it is to peel off and break due to film stress after film formation by sputtering.

Furthermore, flexible display panels have the problem that the wiring formed on the flexible plastic substrate can peel off or break when the panel is bent. Furthermore, the thicker the wiring, the larger the minimum processing dimension becomes, making it difficult to reduce pixel size and achieve high definition.

As a technology for reducing signal delay, a multi-division drive display that divides and drives the display area has been proposed (see, for example, Patent Document 2 below). However, there is a problem in that a driver needs to be provided for each divided area, which increases the number of drivers.

JP 2013-105148 A Patent No. 6462479

The present invention has been proposed in light of the above-mentioned conventional circumstances, and aims to provide a display device and a manufacturing method thereof that can further improve display quality by reducing wiring resistance and suppressing the occurrence of signal delays and their variations.

In order to achieve the above object, the present invention provides the following means.
[1] A display panel including a display area in which a plurality of pixels are arranged in a plane,
the display panel includes a plurality of scanning lines arranged in one direction intersecting within the plane of the display area, and a plurality of signal lines arranged in another direction intersecting within the plane of the display area, and a pixel circuit substrate on one surface of which pixel circuits constituting the pixels are provided for each region partitioned by the plurality of scanning lines and the plurality of signal lines;
a plurality of contact plugs arranged in a thickness direction of the pixel circuit substrate and electrically connected to the plurality of scanning lines;
a plurality of connection parts arranged on the other surface side of the pixel circuit substrate and electrically connected to the plurality of contact plugs, respectively;
A display device comprising: a resin-coated metal foil arranged on the other surface side of the pixel circuit substrate, the metal foil being electrically connected to each of the plurality of connection portions and exposed from the surface of the resin .
[2] The display device according to [1], wherein the resin-coated metal foil is provided in an area that overlaps with the display area in a plan view.
[3] The pixel circuit includes a light-emitting element and a TFT element that switches on and off the light-emitting element,
The display device described in [1] or [2], characterized in that the resin-coated metal foil is electrically connected to the gate electrode of the TFT element via the contact plug and the connection portion, and the gate electrode is electrically connected to the scanning line.
[4] A plurality of display panel units each including the display panel;
a support substrate that supports the plurality of display panel units in a state in which the display panel units are arranged in a plane;
The display device described in any one of [1] to [3] above, characterized in that the display areas of the multiple display panel units form a single display screen by bonding the multiple display panel units to one side of the support substrate with adjacent ones of the multiple display panel units butted together.
[5] The display device according to [4], wherein adjacent ones of the resin-coated metal foils are electrically connected to each other.
[6] A method for manufacturing a display device including a display panel including a display area in which a plurality of pixels are arranged in a plane, comprising the steps of:
a step of producing a pixel circuit substrate in which a plurality of scanning lines are arranged in one direction intersecting within the plane of the display region, a plurality of signal lines are arranged in another direction intersecting within the plane of the display region, and pixel circuits constituting the pixels are provided on one surface side for each region partitioned by the plurality of scanning lines and the plurality of signal lines, when producing the display panel;
forming a plurality of contact plugs electrically connected to the plurality of scanning lines in a thickness direction of the pixel circuit substrate;
forming a plurality of connection portions on the other surface side of the pixel circuit substrate, the connection portions being electrically connected to the plurality of contact plugs, respectively;
and arranging a resin-coated metal foil on the other surface side of the pixel circuit substrate, the metal foil being exposed from the surface of the resin and electrically connected to each of the plurality of connection portions.

As described above, the present invention makes it possible to provide a display device and a manufacturing method thereof that can further improve display quality by reducing wiring resistance and suppressing the occurrence of signal delays and their variations.

1 is a circuit diagram showing a configuration of a display device according to a first embodiment of the present invention. FIG. 2 is a circuit diagram showing a configuration of a pixel circuit. FIG. 2 is a perspective plan view showing a configuration of a pixel circuit substrate. 4 is a cross-sectional view of the pixel circuit substrate taken along line AA in FIG. 3. 4 is a cross-sectional view of the pixel circuit substrate taken along line BB in FIG. 3. 1A to 1C are cross-sectional views illustrating a process for manufacturing a pixel circuit substrate. 1A to 1C are cross-sectional views illustrating a process for manufacturing a pixel circuit substrate. 1A to 1C are cross-sectional views illustrating a process for manufacturing a pixel circuit substrate. 1A to 1C are cross-sectional views illustrating a process for manufacturing a pixel circuit substrate. 1A to 1C are cross-sectional views illustrating a process for manufacturing a pixel circuit substrate. 1A to 1C are cross-sectional views illustrating a process for manufacturing a pixel circuit substrate. FIG. 11 is a cross-sectional view of a main part showing a configuration of a multi-display included in a display device according to a second embodiment of the present invention. FIG. 2 is a plan view of the multi-display as seen from the rear side. FIG. 11 is a cross-sectional view of a main part showing another configuration of a multi-display.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.
In addition, the drawings used in the following description may show characteristic parts in a schematic manner for the sake of convenience in order to make the characteristics easier to understand, and the number of components and dimensional ratios are not necessarily the same as in reality. Furthermore, the materials, dimensions, etc. exemplified in the following description are merely examples, and the present invention is not necessarily limited to them, and can be appropriately changed and implemented within the scope of the present invention.

First Embodiment
[Display Device]
First, as a first embodiment of the present invention, a display device 1A shown in, for example, FIGS. 1 to 5 will be described.

Note that FIG. 1 is a circuit diagram showing the configuration of display device 1A. FIG. 2 is a circuit diagram showing the configuration of pixel circuit 3. FIG. 3 is a perspective plan view showing the configuration of pixel circuit substrate 4. FIG. 4 is a cross-sectional view of pixel circuit substrate 4 taken along line segment A-A shown in FIG. 3. FIG. 5 is a cross-sectional view of pixel circuit substrate 4 taken along line segment B-B shown in FIG. 3.

As shown in Figures 1 to 4, the display device 1A of this embodiment is an organic EL display device (organic EL display) that uses organic EL elements to perform color display, to which the present invention is applied.

Specifically, this display device 1A has a display panel 2 including a display area E in which a plurality of pixels P are arranged side by side within a plane. The display panel 2 has a pixel circuit substrate 4 on which pixel circuits 3 that constitute the pixels P are provided.

The pixel circuit board 4 includes a plurality of scanning lines 5 arranged in one direction (vertical direction in FIGS. 1 and 2) that intersects within the plane of the display area E, and a plurality of signal lines 6 and a plurality of power lines 7 arranged in another direction (horizontal direction in FIGS. 1 and 2) that intersects within the plane of the display area E. The pixel circuit board 4 has a structure in which a pixel circuit 3 is provided for each area partitioned by the plurality of scanning lines 5, the plurality of signal lines 6, and the plurality of power lines 7.

The display panel 2 also has a structure in which a plurality of pixels (called "subpixels") P corresponding to at least the three primary colors of red (R), green (G), and blue (B) are grouped into one pixel unit (called a "pixel") Pu, and these pixel units Pu are periodically arranged within the plane.

In this embodiment, one pixel unit Pu is formed by arranging a pixel P corresponding to red (R), a pixel P corresponding to green (G), and a pixel P corresponding to blue (B) periodically in another direction. Also, in this embodiment, the pixel units Pu, which are rectangular in plan view, are arranged in a matrix on the surface of the display area E, which is rectangular in plan view, to form a display panel 2, which is rectangular in plan view.

The pixel unit Pu is not necessarily limited to the above-mentioned configuration, and for example, it can be configured with four pixels P, including the pixel P corresponding to red (R), green (G), and blue (B) and a pixel P corresponding to white (W). Furthermore, it is not limited to a configuration in which a plurality of pixels P corresponding to the above-mentioned color display is arranged, and it is also possible to have a configuration in which a plurality of pixels P corresponding to monochrome display is arranged. Furthermore, the display area E and the display panel 2 are not necessarily limited to the above-mentioned rectangular shape, and their planar shape can be changed as appropriate.

As shown in Figures 2 and 5, the pixel circuit 3 includes an organic EL element 8, which is a light-emitting element, a capacitor 9, which is a storage capacitance C, and two TFT elements (a selection TFT element 10 and a drive TFT element 11), which are switching elements.

The organic EL element 8 has a structure in which a pixel electrode 13, an organic functional layer 14, and a common electrode 15 are sequentially laminated on one surface (front surface in FIG. 5) of a substrate 12 that constitutes the pixel circuit board 4. In other words, the organic EL element 8 has a structure in which the organic functional layer 14 is sandwiched between the pixel electrode 13, which is the positive electrode (+), and the common electrode 15, which is the negative electrode (-).

The substrate 12 is made of a flexible substrate such as a plastic substrate. In this embodiment, a film-like plastic substrate having a thickness of, for example, 10 μm or less is used as the substrate 12. The plastic substrate is made of a resin material such as polyimide.

The substrate 12 is not necessarily limited to the configuration using the flexible substrate described above, but can also be configured using a rigid substrate such as a glass substrate.

The pixel electrodes 13 are provided corresponding to the plurality of pixels P, respectively. The pixel electrodes 13 are made of a metal electrode material such as aluminum (Al). The pixel electrodes 13 are formed on an interlayer insulating layer 16 that covers a surface on which the two TFT elements 10 and 11, which will be described later, are formed. The interlayer insulating layer 16 is made of, for example, silicon oxide (SiO _x ). The pixel electrodes 13 are electrically connected to the source electrode 11s side of the driving TFT element 11.

The organic functional layer 14 has a structure (called a "heterostructure") in which, for example, a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, and an electron injection layer are stacked in this order. A bank layer 17 is provided on the interlayer insulating layer 16, except on the surface of the pixel electrode 13. The bank layer 17 is made of, for example, a coating-type organic insulating material. The organic functional layer 14 is embedded inside the bank layer 17.

The common electrode 15 constitutes a single solid electrode common to multiple pixels P. The common electrode 15 is made of a transparent electrode material such as indium tin oxide (ITO). The common electrode 15 is formed so as to cover the surface on which the organic functional layer 14 and the bank layer 17 are formed. In addition, a protective layer 18 is formed on the common electrode 15 so as to cover the entire surface of the substrate 12. The protective layer 18 is made of, for example, a coating-type organic insulating material.

The common electrode 15 is electrically connected to a GND line 19. The GND line 19 is provided on the surface of a gate insulating layer 20 that constitutes two TFT elements 10 and 11 described later. The GND line 19 is electrically connected to the common electrode 15 via a contact plug 21a that penetrates the interlayer insulating layer 16, a contact electrode 21b formed on the interlayer insulating layer 16, and a contact plug 21c that penetrates the bank layer 17.

In the organic EL element 8, holes injected and transported from the pixel electrode 13 side through the hole injection layer and hole transport layer, and electrons injected and transported from the common electrode side through the electron injection layer and electron transport layer recombine in the light-emitting layer, thereby making it possible to emit light.

The organic EL element 8 has a top emission structure in which light is extracted from one side of the substrate 12 (hereinafter, one side of the substrate 12 will be referred to as the "front side" and the other side of the substrate 12 will be referred to as the "back side").

When a color display is performed using the organic EL element 8, an organic EL element that emits white light is combined with color filters corresponding to red (R), green (G), and blue (B). Alternatively, a combination of organic EL elements that emit red light, green light, and blue light may be used.

The storage capacitance C is provided such that one end of the capacitor 9 is electrically connected to the source electrode 10s of the selection TFT element 10 and the gate electrode 11g of the drive TFT element 11, and the other end of the capacitor 9 is electrically connected to the source electrode 11s of the drive TFT element 11.

The two TFT elements 10, 11 are provided side by side on a substrate 12. The two TFT elements 10, 11 use an oxide semiconductor such as an oxide of indium (In)-tin (Sn)-zinc (Zn) (InSnZnO). The oxide semiconductor may be an oxide containing at least one metal element such as In, gallium (Ga), Zn, Sn, or Al, or may be polycrystalline silicon, amorphous silicon, or an organic semiconductor. The gate insulating layer 20 uses, for example, silicon oxide (SiO _x ).

The selection TFT element 10 is provided with a gate electrode 10g electrically connected to the scanning line 5, a drain electrode 10d electrically connected to the signal line 6, and a source electrode 10s electrically connected to the gate electrode 11g of the drive TFT element 11 and one end of the storage capacitance C (capacitor 9).

The driving TFT element 11 is provided with a gate electrode 10g electrically connected to the source electrode 10s of the selection TFT element 10 and the storage capacitance C (one end of the capacitor 9), a drain electrode 11d electrically connected to the power line 7, and a source electrode 11s electrically connected to the pixel electrode 13 and the other end of the storage capacitance C (capacitor 9).

In the display panel 2, the potential (image data) of the signal line 6 is held in the storage capacitor C via the selection TFT element 10 by the switching operation of the selection TFT element 10. In addition, depending on the potential of the storage capacitor C, a drive current flows from the power line 7 to the organic EL element 8 via the drive TFT element 11. This makes it possible to cause the organic EL element 8 to emit light (light up).

As shown in Figures 3, 4 and 5, the pixel circuit board 4 of this embodiment has a plurality of contact plugs 31 arranged in the thickness direction of the substrate 12, a plurality of connection parts 32 arranged on the other surface side of the substrate 12, and a resin-coated metal foil 33 arranged on the other surface side of the substrate 12.

The contact plugs 31 are electrically connected to each of the pixel circuits 3. The connection parts 32 are electrically connected to each of the contact plugs 31. The resin-coated metal foil 33 is electrically connected to each of the connection parts 32.

The contact plug 31 is formed by embedding a coating type conductive material, such as silver (Ag) paste, in a contact hole penetrating the substrate 12. The connection portion 32 is formed integrally with the contact plug 31 using the same material as the contact plug 31.

The resin-coated metal foil 33 has a structure in which a metal foil 33a made of, for example, aluminum (Al) is embedded in a resin 33b such as an epoxy resin. The metal foil 33a is formed almost flush with the resin 33b on the surface side of the resin-coated metal foil 33, and is exposed from the surface of the resin 33b. In this embodiment, the resin-coated metal foil 33 has a thickness of, for example, 15 μm or more.

The metal foil 33a is electrically connected to the connection portion 32 with the rear surface of the substrate 12 facing the surface of the resin-coated metal foil 33. As a result, the metal foil 33a is electrically connected to the gate electrode 10g of the selection TFT element 10 via the contact plug 31 and the connection portion 32. In other words, the metal foil 33a is electrically connected to the gate electrodes 10g of multiple selection TFT elements 10, thereby functioning as an auxiliary electrode for the scanning line 5. The resin-coated metal foil 33 is provided in an area that overlaps with the display area E in a planar view.

In the display device 1A of the embodiment having the above-mentioned configuration, the metal foil 33a of the resin-coated metal foil 33 described above functions as an auxiliary electrode for the scanning line 5, thereby reducing the wiring resistance of the scanning line 5 and suppressing the occurrence of signal delay and its variation. As a result, the display device 1A of the embodiment can further improve the display quality of the display panel 2.

In addition, the resin-coated metal foil 33 has a thickness of 15 μm or more, and the metal foil 33a is embedded in the resin 22b. As a result, the metal foil 33a is less likely to break or peel off, even if the pixel circuit board 4 is curved, compared to a metal film formed by sputtering. In addition, the metal foil 33a can be used to form thick wiring with a width corresponding to the selection TFT element 10.

[Display Device Manufacturing Method]
Next, a method for manufacturing the display device 1A will be described with reference to FIGS.
6 to 11 are cross-sectional views for explaining the process of manufacturing the pixel circuit substrate 4. As shown in FIG.

The manufacturing method of the display device 1A of this embodiment includes a process of fabricating the pixel circuit substrate 4 when manufacturing the display panel 2.

In the process of producing the pixel circuit board 4, first, as shown in FIG. 6, a substrate 12 formed in a film shape on the surface of a first glass substrate 101 is prepared. Then, on one surface (front surface) of this substrate 12, the above-mentioned scanning lines 5, signal lines 6, power supply lines 7, and GND lines 19, contact plugs 21a, contact electrodes 21b, and contact plugs 21c, the organic EL element 8 (pixel electrode 13, organic functional layer 14, and common electrode 15) constituting the pixel circuit 3, the capacitor 9, the selection TFT element 10 including the gate insulating layer 20, and the driving TFT element 11, the interlayer insulating layer 16, the bank layer 17, and the protective layer 18 are formed.

These formation processes can be performed using conventionally known film formation processes, photolithography processes, and the like, and there are no particular limitations on the formation method.

Next, as shown in FIG. 7, a second glass substrate 103 is attached to the top layer of the substrate 12 via an adhesive layer 102.

Next, as shown in FIG. 8, laser light L is irradiated from the first glass substrate 101 side toward the substrate 12. At this time, the laser light L passes through the first glass substrate 101 and is absorbed by the substrate 12, causing a part of the plastic film near the interface with the first glass substrate 101 to evaporate due to heat. This allows the first glass substrate 101 to be peeled off from the other surface (rear surface) of the substrate 12, as shown in FIG. 9.

Next, as shown in FIG. 10, a contact hole 104 is formed through the substrate 12 at the position where the contact plug 31 is to be formed on the substrate 12.

Next, as shown in FIG. 11, a coating-type conductive material such as silver (Ag) paste is applied using a dispenser and then patterned into a predetermined shape. This results in the contact plug 31 embedded in the contact hole 104 and the connection part 32 arranged on the back surface of the substrate 12 being integrally formed.

Next, with the back surface of the substrate 12 facing the surface of the resin-coated metal foil 33, the gate electrode 10g of the selection TFT element 10 is electrically connected to the connection portion 32. Finally, the second glass substrate 103 is removed together with the adhesive layer 102. This makes it possible to fabricate the pixel circuit substrate 4.

In the manufacturing method of the display device 1A of this embodiment, the metal foil 33a of the resin-coated metal foil 33 described above functions as an auxiliary electrode for the scanning line 5, thereby making it possible to manufacture a display panel 2 that can reduce the wiring resistance of the scanning line 5 and suppress the occurrence of signal delays and their variations.

Second Embodiment
[Display Device]
Next, as a second embodiment of the present invention, a display device 1B shown in, for example, FIGS. 11 to 14 will be described.

Note that FIG. 12 is a cross-sectional view of the main parts of the configuration of the multi-display 2B provided in the display device 1B. FIG. 13 is a plan view of the multi-display 2B from the back side. FIG. 14 is a cross-sectional view of the main parts of another configuration of the multi-display 2B. In the following explanation, the same parts as those in the display device 1A will not be described and will be given the same reference numerals in the drawings.

As shown in Figs. 12 and 13, the display device 1B of this embodiment constitutes a multi-display, and includes a plurality of display panel units 41 constituted by the display panel 2, and a support substrate 42 that supports the plurality of display panel units 41 in a state in which they are arranged in a plane.

In the display device 1B, the display areas E of the multiple display panel units 41 form a single display screen S by butting adjacent ones of the multiple display panel units 41 together and bonding the front sides of the multiple display panel units 41 to one side of a support substrate 42 via an adhesive layer 43.

In this embodiment, nine display panel units 41 are arranged in a vertical arrangement of three and a horizontal arrangement of three, but the number of display panel units 41 can be changed as appropriate.

The support substrate 42 is made of a transparent flexible substrate such as a plastic substrate, and has a shape corresponding to the display screen S. The plastic substrate is made of a resin material such as polyimide. Note that the support substrate 42 is not necessarily limited to the configuration using the flexible substrate described above, and when a rigid substrate is used for the substrate 12, it is also possible to use a transparent rigid substrate such as a glass substrate.

The adhesive layer 43 is made of a transparent adhesive material, such as an epoxy resin adhesive.

Of the multiple display panel units 41, the multiple display panel units 41 (hereinafter, distinguished as "display panel unit 41A" as necessary) that are located at one end side (right end side in FIG. 13) of the other direction (horizontal direction in FIG. 13) and lined up in one direction (vertical direction in FIG. 13) have multiple first flexible printed circuit boards (FPCs) 45 on which scanning line driving circuits (gate drivers) 44 are provided.

On the rear side of each display panel unit 41A, multiple first FPCs 45, each having a gate driver 44 for each row of multiple scanning lines 5, are arranged in one direction (vertical direction in Figure 13).

The gate driver 44 includes, for example, a shift register and a level shifter, and is electrically connected to the multiple scanning lines 5 via the first FPC 45A. The gate driver 44 sequentially supplies scanning signals to the multiple scanning lines 5, and switches the driving of the selection TFT elements 10 in response to the scanning signals.

On the other hand, the multiple display panel units 41 have multiple second flexible printed circuit boards (FPCs) 47 on which signal line driving circuits (data drivers) 46 are provided.

On the rear side of each display panel unit 41, multiple second FPCs 47, each of which has a data driver 46 for each of the signal lines 6, are arranged in the other direction (horizontal direction in FIG. 13).

The data driver 37 includes, for example, a shift register, a level shifter, a video line, and an analog switch, and is electrically connected to the multiple signal lines 6 via the second FPC 35B. The data driver 37 supplies image data to the multiple signal lines 6.

In the display device 1B of this embodiment, on the rear side of each display panel unit 41A, each gate driver 44 is electrically connected to each metal foil 33a of the resin-coated metal foil 33 via a first FPC 45.

Specifically, contact plug 33c, back surface wiring 33d, and connection portion 33e are provided on the back surface side of resin-coated metal foil 33. Contact plug 33c is disposed in the thickness direction of resin 33b and is electrically connected to metal foil 33a. Back surface wiring 33d is disposed on the back surface of resin 33b and is electrically connected to contact plug 33c. In other words, metal foil 33a and back surface wiring 33d are electrically connected via contact plug 33c.

The contact plugs 33c are formed by embedding a conductive material such as copper, aluminum, molybdenum, or chromium in contact holes that penetrate the resin 33b. The back wiring 33d is formed in a linear pattern on the back surface of the resin 33b by using a conductive material such as copper, aluminum, molybdenum, or chromium.

The metal foil 33a, contact plug 33c, and back surface wiring 33d are provided corresponding to each of the multiple scanning lines 5. That is, each scanning line 5 is routed from the front side to the back side of the resin-coated metal foil 33 by the metal foil 33a, contact plug 33c, and back surface wiring 33d.

The connection portion 33e electrically connects each of the multiple back wirings 33d arranged in a line row corresponding to each of the multiple scanning lines 5 to each of the multiple terminals provided on one end side of the first FPC 45.

The connection portion 33e is formed by using a connection material such as anisotropic conductive film (ACF) or anisotropic conductive paste (ACP) to cross between the multiple back wirings 33d, and while maintaining insulation between each back wiring 33d, it is made conductive at the positions where it overlaps with each back wiring 33d, thereby electrically connecting each back wiring 33d to each terminal of the first FPC 45 and bonding the first FPC 45 to the resin-coated metal foil 33.

In the display device 1B of the embodiment having the above-mentioned configuration, the metal foil 33a of the resin-coated metal foil 33 described above functions as an auxiliary electrode for the scanning line 5, thereby reducing the wiring resistance of the scanning line 5 and suppressing the occurrence of signal delay and its variation. As a result, the display device 1B of the embodiment can further improve the display quality of each display panel unit 41.

In addition, in the display device 1B of the embodiment, the metal foils 33a of the resin-coated metal foil 33 are electrically connected between the multiple display panel units 41 adjacent in the horizontal direction described above. This allows the gate driver 44 provided in the rightmost display panel unit 41A to drive the multiple display panel units 41 adjacent in the horizontal direction while connecting the scanning lines 5 between the multiple display panel units 41 adjacent in the horizontal direction. Therefore, it is no longer necessary to provide a gate driver 44 in all display panel units 41, and it is possible to reduce the number of gate drivers 44 provided.

In addition, in the display device 1B of the embodiment, a resin-coated metal foil 33 is arranged in an area that overlaps with the display area E of each display panel unit 41 described above in a planar view, and a gate driver 44 provided on the first FPC 45 and a data driver 46 provided on the first FPC 45 can be arranged on the back side of this resin-coated metal foil 33.

This eliminates the need to provide a peripheral area for arranging the gate driver 44 and data driver 46 outside the display area E of each display panel unit 41, making it possible to reduce the peripheral area of each display panel unit 41. Therefore, when multiple display panel units 41 are arranged in a plane as a multi-display to display as a single screen, it is possible to configure a seamless (unnoticeable) display screen S.

Note that, although the display device 1B is exemplified by the configuration shown in FIG. 12 above, the display device 1B is not necessarily limited to such a configuration, and may be configured as shown in FIG. 14, for example.

Specifically, in the display device 1B shown in FIG. 14, a contact plug 34, a back surface wiring 35, and a connection portion 36 are provided on the back surface side of the pixel circuit substrate 4 constituting the display panel unit 41A. On the other hand, the contact plug 33c, the back surface wiring 33d, and the connection portion 33e provided on the resin-coated metal foil 33 are omitted.

The contact plug 34 is disposed in the thickness direction of the substrate 12 and is electrically connected to the gate electrode 10g of the selection TFT element 10. The back wiring 35 is disposed on the back surface of the substrate 12 and is electrically connected to the contact plug 34. In other words, the gate electrode 10g of the selection TFT element 10 and the back wiring 35 are electrically connected via the contact plug 34.

The contact plug 34 is formed by embedding the contact hole penetrating the substrate 12 using the same conductive material as the contact plug 33c. The back surface wiring 35 is formed in a linear pattern on the back surface of the substrate 12 using the same conductive material as the back surface wiring 33d.

The contact plugs 34 and back surface wiring 35 are provided corresponding to each of the multiple scanning lines 5. That is, each scanning line 5 is routed from the front side to the back side of the substrate 12 by these contact plugs 34 and back surface wiring 35.

The connection portion 36 electrically connects each of the multiple rear wirings 35 arranged in a line row corresponding to each of the multiple scanning lines 5 to each of the multiple terminals provided on one end side of the first FPC 45. The connection portion 36 is the same as the connection portion 33e described above.

In this case, the scanning lines 5 can be connected between horizontally adjacent display panel units 41, and the gate driver 44 provided in the rightmost display panel unit 41A can drive the display panel units. Therefore, it is no longer necessary to provide a gate driver 44 in every display panel unit 41, and it is possible to reduce the number of gate drivers 44 provided.

The present invention is not necessarily limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, in the above embodiment, the present invention is applied to the above-mentioned organic EL display, but the light-emitting element is not necessarily limited to an organic EL element, and may be an LED element such as a micro LED, or a light-emitting element such as a quantum dot. The present invention can also be applied to a liquid crystal display or the like.

1A, 1B... Display device 2... Display panel 3... Pixel circuit 4... Pixel circuit board 5... Scanning line 6... Signal line 7... Power supply line 8... Organic EL element 9... Capacitor 10... Selection TFT element 11... Driving TFT element 12... Substrate 13... Pixel electrode 14... Organic functional layer 15... Common electrode 16... Interlayer insulating layer 17... Bank layer 18... Protective layer 19... GND line 20... Gate insulating layer 31... Contact plug 32... Connection portion 33... Metal foil with resin 33a... Metal foil 33b... Resin 33c... Contact plug 33d... Back wiring 33e... Connection portion 34... Contact plug 35... Back wiring 36... Connection portion 41... Display panel unit 42... Support substrate 43... Adhesive layer 44... Scanning line driving circuit (gate driver) 45... First flexible printed wiring board (FPC) 46: Signal line driving circuit (data driver) 47: Second flexible printed circuit board (FPC) C: Storage capacitor P: Pixel Pu: Pixel unit E: Display area S: Display screen

Claims (6)

A display panel including a display area in which a plurality of pixels are arranged in a plane,
the display panel includes a plurality of scanning lines arranged in one direction intersecting within the plane of the display area, and a plurality of signal lines arranged in another direction intersecting within the plane of the display area, and a pixel circuit substrate on one surface of which pixel circuits constituting the pixels are provided for each region partitioned by the plurality of scanning lines and the plurality of signal lines;
a plurality of contact plugs arranged in a thickness direction of the pixel circuit substrate and electrically connected to the plurality of scanning lines;
a plurality of connection parts arranged on the other surface side of the pixel circuit substrate and electrically connected to the plurality of contact plugs, respectively;
A display device comprising: a resin-coated metal foil arranged on the other surface side of the pixel circuit substrate, the metal foil being electrically connected to each of the plurality of connection portions and exposed from the surface of the resin . The display device according to claim 1, characterized in that the resin-coated metal foil is provided in an area that overlaps with the display area in a plan view. the pixel circuit includes a light-emitting element and a TFT element that switches on and off the light-emitting element;
3. The display device according to claim 1, wherein the resin-coated metal foil is electrically connected to a gate electrode of the TFT element via the contact plug and the connection portion, and the gate electrode is electrically connected to the scanning line. a plurality of display panel units each including the display panel;
a support substrate that supports the plurality of display panel units in a state in which the display panel units are arranged in a plane;
A display device as described in any one of claims 1 to 3, characterized in that the display areas of the multiple display panel units form a single display screen by bonding the multiple display panel units to one side of the support substrate with adjacent ones of the multiple display panel units butted together. The display device according to claim 4, characterized in that adjacent pieces of the resin-coated metal foil are electrically connected to each other. A method for manufacturing a display device including a display panel including a display region in which a plurality of pixels are arranged side by side in a plane, comprising the steps of:
a step of producing a pixel circuit substrate in which a plurality of scanning lines are arranged in one direction intersecting within the plane of the display region, a plurality of signal lines are arranged in another direction intersecting within the plane of the display region, and pixel circuits constituting the pixels are provided on one surface side for each region partitioned by the plurality of scanning lines and the plurality of signal lines, when producing the display panel;
forming a plurality of contact plugs electrically connected to the plurality of scanning lines in a thickness direction of the pixel circuit substrate;
forming a plurality of connection portions on the other surface side of the pixel circuit substrate, the connection portions being electrically connected to the plurality of contact plugs, respectively;
and arranging a resin-coated metal foil on the other surface side of the pixel circuit substrate, the metal foil being exposed from the surface of the resin and electrically connected to each of the plurality of connection portions.

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