JP7086610B2 - Display device - Google Patents

Description

One embodiment of the present invention relates to a display device and a method for manufacturing the display device.

As a display device used in electric appliances and electronic devices, a display device using a liquid crystal display element utilizing the electro-optical effect of liquid crystal or a display using an organic electroluminescence (organic EL) element as a display element. The device has been developed and commercialized. Further, a touch panel, which is a display device in which a touch sensor is mounted on a display element, has rapidly become widespread in recent years. Touch panels have become indispensable for mobile information terminals such as smartphones, and are being developed worldwide for the further progress of the information-oriented society.

The touch panel includes a method in which a touch sensor is manufactured on a substrate separate from the display device and bonded to each other, and a method in which the touch sensor is incorporated inside the display device (sometimes referred to as an on-cell method). Patent Document 1 discloses the structure of the touch panel.

JP-A-2015-050245

On the other hand, when the on-cell method is used, it is necessary to newly provide an electrode or wiring (sometimes referred to as a sensor electrode or sensor wiring) and an insulating layer on the display element. However, since the display element may be damaged by heat, the temperature range at the time of forming the sensor electrode or the sensor wiring and the insulating layer may be limited.

Further, in the case of the on-cell method, the unevenness caused by the insulating layer formed on the display element is large, and the sensor electrode or the sensor wiring may be disconnected.

In view of such a problem, one of the objects of the present invention is to provide a display device for preventing disconnection of wiring for a touch sensor without deteriorating the performance of the display element. Another object of the present invention is to provide a display device for improving the detection speed of the touch sensor.

According to one embodiment of the present invention, the first insulating layer, the first conductive layer on the first insulating layer, the first insulating layer, the second insulating layer on the first conductive layer, and the second insulating layer. A first sensor electrode that partially overlaps the first conductive layer, a pixel electrode arranged apart from the first sensor electrode on the second insulating layer, a light emitting layer on the pixel electrode, and a common light on the light emitting layer. The first sensor electrode comprises an electrode and a third insulating layer disposed on the second insulating layer and the first sensor electrode, covering the peripheral edge of the pixel electrode and exposing the inner region of the pixel electrode. (2) A display device is provided, which is connected to the first conductive layer by an opening penetrating the insulating layer.

According to another embodiment of the present invention, the first conductive layer is formed on the first insulating layer, the second insulating layer is formed on the first insulating layer and the first conductive layer, and the second insulating layer is opened. A portion is formed, a first sensor electrode is formed on the second insulating layer so as to be in contact with the first conductive layer at an opening, and a pixel electrode is formed on the second insulating layer so as to be separated from the first sensor electrode. Provided is a method for manufacturing a display device, which forms a third insulating layer on the second insulating layer and the first sensor electrode and covers the peripheral edge of the pixel electrode so that the inner region of the pixel electrode is exposed. Will be done.

It is a top view which shows the structure of the display device which concerns on one Embodiment of this invention. It is a circuit diagram of the pixel circuit in the pixel of the display device which concerns on one Embodiment of this invention. It is a top view which shows the touch sensor which concerns on one Embodiment of this invention. It is a top view which shows a part of the touch sensor which concerns on one Embodiment of this invention. It is sectional drawing which shows a part of the touch sensor which concerns on one Embodiment of this invention. It is sectional drawing which shows the structure of the display device which concerns on one Embodiment of this invention. It is sectional drawing explaining the manufacturing method of the display device which concerns on one Embodiment of this invention. It is sectional drawing explaining the manufacturing method of the display device which concerns on one Embodiment of this invention. It is sectional drawing explaining the manufacturing method of the display device which concerns on one Embodiment of this invention. It is sectional drawing explaining the manufacturing method of the display device which concerns on one Embodiment of this invention. It is sectional drawing explaining the manufacturing method of the display device which concerns on one Embodiment of this invention. It is sectional drawing explaining the manufacturing method of the display device which concerns on one Embodiment of this invention. It is sectional drawing explaining the manufacturing method of the display device which concerns on one Embodiment of this invention. It is sectional drawing explaining the manufacturing method of the display device which concerns on one Embodiment of this invention. It is sectional drawing which shows a part of the touch sensor which concerns on one Embodiment of this invention. It is sectional drawing which shows the structure of the display device which concerns on one Embodiment of this invention. It is a top view which shows a part of the touch sensor which concerns on one Embodiment of this invention. It is sectional drawing which shows a part of the touch sensor which concerns on one Embodiment of this invention. It is sectional drawing which shows a part of the touch sensor which concerns on one Embodiment of this invention. It is a top view which shows a part of the touch sensor which concerns on one Embodiment of this invention. It is sectional drawing which shows a part of the touch sensor which concerns on one Embodiment of this invention. It is sectional drawing which shows the structure of the display device which concerns on one Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. It should be noted that the disclosure is merely an example, and those skilled in the art can easily conceive of appropriate changes while maintaining the gist of the invention, which are naturally included in the scope of the present invention. Further, in order to clarify the explanation, the drawings may schematically represent the width, thickness, shape, etc. of each part as compared with the actual embodiment, but this is just an example, and the interpretation of the present invention is used. It is not limited. Further, in the present specification and each figure, the same elements as those described above with respect to the above-mentioned figures are designated by the same reference numerals (or reference numerals followed by -1, -2, etc.) in detail. The description may be omitted as appropriate. Furthermore, the letters "1st" and "2nd" for each element are convenient signs used to distinguish each element, and have no further meaning unless otherwise specified. ..

Further, in the detailed description of the present invention, when defining the positional relationship between a certain component and another component, "above" and "below" are used only when they are located directly above or directly below a certain component. However, unless otherwise specified, it shall include the case where other components are intervened between them.

Further, in the present specification, the terms "conductive layer", "electrode", and "wiring" have the same meaning and can be replaced depending on the situation.

<First Embodiment>
(1-1. Configuration of display device)
FIG. 1 is a top view of the display device 10 according to the present embodiment. In FIG. 1, the display device 10 includes a substrate 100, a display unit 103, a peripheral portion 104, a drive circuit 105, a drive circuit 106, a flexible printed circuit board 108, and a terminal unit 109. The drive circuit 105 has a function as a gate driver. The drive circuit 106 has a function as a source driver and a function of controlling a touch sensor described later. Pixels 101 including display elements are arranged in a grid pattern on the display unit 103. The flexible printed board 108 is electrically connected to the terminal portion 109. The terminal portion 109 is connected to the signal line 147b and also to the drive circuit 105.

FIG. 2 shows a circuit diagram of the pixel circuit PX in the pixel 101. The circuit configuration of the pixel circuit described below is an example, and is not limited to this.

The pixel circuit PX is a circuit for driving the pixel 101, and includes a drive transistor 132, a selection transistor 134, a light emitting element 136, and a holding capacity 138. The drive transistor 132 corresponds to the transistor 110 described later. The light emitting element 136 corresponds to the display element 300 described later. The holding capacity 138 corresponds to the capacitance element 120 described later.

The drive transistor 132 is a transistor connected to the light emitting element 136 and controlling the light emitting brightness of the light emitting element 136. The drain current of the drive transistor 132 is controlled by the gate-source voltage. In the drive transistor 132, the gate is connected to the drain of the selection transistor 134, the source is connected to the drive power line 128, and the drain is connected to the anode of the light emitting element 136.

The selection transistor 134 is a transistor that controls the conduction state between the (video) signal line 147b and the gate of the drive transistor 132 by on / off operation. In the selection transistor 134, the gate is connected to the scanning line 145c, the source is connected to the (video) signal line 109, and the drain is connected to the gate of the drive transistor 132.

In the light emitting element 136, the anode (pixel electrode 155 described later) is connected to the drain of the drive transistor 132, and the cathode (common electrode 160 described later) is connected to the reference power supply line 126.

The holding capacity 138 is connected between the gate and the source of the drive transistor 132. The holding capacity 138 holds the gate-source voltage of the drive transistor 132.

Here, the reference power supply line 126 is provided in common to the plurality of pixel circuits PX. A constant potential is applied to the reference power supply line from a part of the terminal electrodes arranged in the terminal portion 109.

The power supply circuit that generates a constant voltage is connected to a reference power supply line 126 that is commonly provided in the plurality of pixel circuits PX, and gives a constant potential to the cathode of the light emitting element 136.

In the display device 10, a video signal is input to the drive circuit 106 via the flexible printed circuit board 108. Next, the drive circuit 105 and the drive circuit 106 drive the pixel 101 via the scan line 145c and the signal line 147b (that is, the drive transistor 132 and the selection transistor 134 are driven, and a current flows through the light emitting element 136). As a result, still images and moving images are displayed on the display unit 103.

(1-2. Configuration of touch sensor)
Next, the configuration of the touch sensor will be described as an example of the detection element. FIG. 3 is a top view of the touch sensor 20 provided in the display device 10. The touch sensor 20 is provided so as to overlap with the display unit 103. The touch sensor 20 includes a first sensor electrode 153-1 and a second sensor electrode 153-2 in top view. The first sensor electrode 153-1 and the second sensor electrode 153-2 are collectively referred to as a conductive layer 153. In the following, when it is not necessary to explain separately, it will be described as a conductive layer 153.

As shown in FIG. 3, the first sensor electrode 153-1 functions as wiring extending in the long side direction (sometimes referred to as the first direction D1) of the display unit 103 (this is referred to as the first sensor). Wiring 1153-1). The first sensor wiring 1153-1 is arranged side by side in the short side direction (sometimes referred to as the second direction D2) of the display unit 103. The first direction D1 and the second direction D2 intersect. The first sensor electrode 153-1 functions as a transmission electrode in the touch sensor 20. Similarly, the second sensor electrode 153-2 functions as a wiring extending and arranged in the second direction D2 (this may be referred to as a second sensor wiring 1153-2). The second sensor wiring 1153-2 is arranged side by side in the first direction D1. The second sensor electrode 153-2 functions as a receiving electrode in the touch sensor 20. The first sensor electrode 153-1 may be a receiving electrode, and the second sensor electrode 1532 may be a transmitting electrode. The first sensor wiring 1153-1 and the second sensor wiring 1153-2 are connected to the terminal electrode 109-1 of the terminal portion 109. The terminal electrode 109-2 is used for displaying the above-mentioned moving images and still images. In a plan view, the terminal electrode 109-2 is arranged so as to be sandwiched between the terminal electrodes 109-1.

FIG. 4 shows an enlarged top view of the area 20A of the touch sensor 20. Further, FIG. 5 shows a cross-sectional view between A1 and A2 of the region 20A. In FIG. 5, the touch sensor 20 is arranged on the insulating layer 150 and includes a conductive layer 151a, an insulating layer 154, and a conductive layer 153. The conductive layer 153 (first sensor electrode 153-1 and second sensor electrode 153-2) is arranged so as to surround the pixel 101. (That is, the first sensor electrode 153-1 and the second sensor electrode 153-2 may have a mesh pattern). A display element 130, which will be described later, is arranged on the pixel 101. Further, the first sensor electrode 153-1 and the second sensor electrode 153-2 each have a protruding portion 153C. Further, in the touch sensor 20, a dummy electrode 154 is arranged adjacent to the first sensor electrode 153-1 and the second sensor electrode 153-2. By arranging the protruding portion 153C and the dummy electrode 154, the electrode pattern density on the substrate 100 becomes constant when the touch sensor 20 is formed, so that the first sensor electrode 153-1 and the second sensor electrode 153- The shape of 2 can be stabilized.

The insulating layer 150 has a flat surface. Therefore, the insulating layer 150 has a function as a flattening film. The insulating layer 150 contains an organic insulating material such as an organic resin (for example, acrylic resin or epoxy resin). Although not particularly shown, it may be formed as a laminate of, for example, an organic insulating material and an inorganic insulating material.

The conductive layer 151a is provided on the insulating layer 150. Both are formed of a metal material selected from tantalum, tungsten, titanium, molybdenum, aluminum and the like. The conductive layer 151a may have a single-layer structure or a laminated structure of the above-mentioned metal material. When the above-mentioned metal material is used, the resistivity of the conductive layer 151a can be lowered.

The conductive layer 151a is not limited to the above-mentioned metal material. The conductive layer 151a may be a conductive material containing oxygen such as indium zinc oxide (IZO), indium tin oxide (ITO), zinc oxide (ZnO), and zinc indium tin oxide (ITZO). When these materials are used, the adhesion to the insulating layer 150 can be improved.

The insulating layer 154 is provided on the insulating layer 150 and the conductive layer 151a. Silicon oxide, silicon oxynitride, silicon nitride or other high dielectric constant inorganic materials are used for the insulating layer 154.

The conductive layer 153 is provided on the insulating layer 154. The conductive layer 153 may use the same material as the conductive layer 151a, or may use a different material. For example, a laminated material of titanium, aluminum, and titanium is used for the conductive layer 153.

As shown in FIGS. 3 to 5, the second sensor electrode 153-2 is arranged apart from the first sensor electrode 153-1. The first sensor electrode 153-1 and the second sensor electrode 153-2 are arranged on the same surface (in this case, the surface of the insulating layer 154).

A plurality of first sensor electrodes 153-1 (first sensor wiring 1153-1) are provided apart from each other in order to extend in the D1 direction. A plurality of second sensor electrodes 153-2 (second sensor wiring 1153-2) are provided apart from each other in order to extend in the D2 direction. The first sensor electrode 153-1 is arranged so as to partially overlap the conductive layer 151a. Specifically, the first sensor electrode 153-1 is a conductive layer in a portion where the first sensor wiring 1153-1 and the second sensor wiring 1153-2 intersect, that is, in the opening 154A penetrating the insulating layer 154. It is connected to 151a. As a result, adjacent ones of the plurality of first sensor electrodes 153-1 are connected to each other by the conductive layer 151a. The second sensor electrode 153-2 is provided only by the conductive layer 153 without using the conductive layer 151a. In the above, it can be said that the first sensor electrode 153-1 (first sensor wiring 1153-1) intersects with each other via the conductive layer 151a and the insulating layer 154 when extending in the first direction D1. Therefore, it is possible to prevent the first sensor electrode 153-1 and the second sensor electrode 153-2 from being short-circuited.

Further, a pixel electrode 155, which is a part of the display element 130, is arranged on the insulating layer 154 at a distance from the first sensor electrode 153-1. In FIG. 5, the conductive layer 153 is arranged under the pixel electrode 155. This can reduce the resistance of the pixel electrodes, but it is not always necessary depending on the resistance value.

Further, the bank layer 157 is arranged on the conductive layer 151a and the conductive layer 153. The bank layer 157 has a flat surface on the upper surfaces of the conductive layer 151a and the conductive layer 153. As a result, the unevenness generated by the conductive layer 151a and the conductive layer 153 is flattened by the bank layer 157.

Further, the bank layer 157 covers the peripheral edge portion of the pixel electrode 155 and exposes the inner region of the pixel electrode 155. As a result, a plurality of openings 157A are provided in a grid pattern. A display element 130 is arranged in the opening 157A. Although the details will be described later, in the display element 130, the pixel electrode 155, the light emitting layer (organic EL layer 159), and the common electrode 160 are laminated in this order. That is, it can be said that the display element 130 is an organic EL element.

Further, as shown in FIG. 5, in the present embodiment, the display element 130 is arranged on the conductive layer 153 and the capacitive electrode 151b. At this time, since the conductive layer 153 and the capacitance electrode 151b are arranged flat, the display element 130 is not easily affected by the unevenness. Therefore, it is possible to prevent the layers (specifically, the pixel electrode 155, the organic EL layer 159, and the common electrode 160, which will be described later) used for the display element 130 from being disconnected. Further, the conductive layer 153a may be arranged on the insulating layer 154. The conductive layer 153a can reduce the resistance value of the pixel electrode 155. At this time, the first sensor electrode 153-1, the second sensor electrode 153-2, and the conductive layer 153a are arranged on the same layer (that is, the insulating layer 154). That is, it can be said that the first sensor electrode 153-1, the second sensor electrode 153-2, and the conductive layer 153a are the same layer electrodes.

(1-3. Drive of touch sensor)
Here, the drive of the touch sensor will be described with reference to FIGS. 3 and 4. The first sensor wiring 1153-1 and the second sensor wiring 1153-2 are connected to the drive circuit 106 via the terminal portion 109. A voltage supplied from the drive circuit 106 to the first sensor electrode 153-1 via the first sensor wiring 1153-1 generates an electric field between the first sensor electrode 153-1 and the second sensor electrode 153-1. do. At this time, when a human finger touches the display device 10, an electric field change occurs between the first sensor electrode 153-1 and the second sensor electrode 153-2. This causes a change in capacitance between the wirings. Next, predetermined information is input to the drive circuit 106 from the second sensor electrode 153-2 via the second sensor wiring 1153-2. As a result, the position information is detected.

In the configuration according to the present embodiment, since the first sensor electrode 153-1 and the second sensor electrode 153-2 are provided on the same layer (specifically, the insulating layer 154), a small capacitance change occurs. Can be detected. Therefore, the detection accuracy of the touch sensor is improved. Further, in the above-mentioned first sensor electrode 153-1 and the second sensor electrode 1532, by arranging the protruding portion 153C and the dummy electrode 154, the electric field between the sensor electrodes can be strengthened, and further, the touch sensor can be used. Detection accuracy is improved.

(1-4. Configuration of each layer of the display device)
FIG. 6 is a cross-sectional view of the display unit 103 (pixel 101) of the display device 10 shown in FIGS. 1 to 5 and a cross-sectional view from the peripheral portion 104 to the terminal portion 109. As shown in FIG. 6, in addition to the above-mentioned touch sensor 20, insulating layer 150, display element 130, and bank layer 157, the display device 10 includes a substrate 100, a transistor 110, a capacitive element 120, a capacitive element 121, and an insulating layer 141. It has an insulating layer 149, a sealing layer 161 and an overcoat layer 170.

In FIG. 6, the transistor 110 has a semiconductor layer 142, a gate insulating layer 143, a gate electrode 145a, and a source / drain electrode 147a. The transistor 110 has a top gate / top contact structure, but is not limited to this, and may have a bottom gate structure or a bottom contact structure.

Further, in the capacitive element 120, the source or drain region of the semiconductor layer 142 and the capacitive electrode 145b are used with the gate insulating layer 143 as a dielectric. Further, in the capacitive element 121, the capacitive electrode 151b and the pixel electrode 155 are used with the insulating layer 154 as a dielectric. The capacitive electrode 151b is superimposed on the pixel electrode 155. Both the conductive layer 151a and the capacitive electrode 151b are arranged apart from each other on the insulating layer 150. That is, it can be said that the conductive layer 151a and the capacitive electrode 151b are provided on the same surface.

Further, as the display element 130, a pixel electrode 155, an organic EL layer 159, and a common electrode 160 are used. That is, it can be said that the display element 130 is an organic EL element. The display element 130 has a so-called top emission type structure in which the light emitted by the organic EL layer 159 is radiated to the common electrode 160 side. The display element 130 is not limited to the top emission type, and may have a bottom emission type structure.

As the substrate 100, a glass substrate or an organic resin substrate is used. When an organic resin substrate is applied, it becomes possible to realize a flexible sheet display. Further, the substrate 100 may be required to be transparent in order to take out the light emitted from the display element to the outside. Since the substrate on the side that does not take out the emitted light from the display element does not need to be transparent, other inorganic materials or metal materials may be used in addition to the above-mentioned materials. The thickness of the substrate 100 is not particularly limited, but is preferably 50 μm or more and 500 μm or less, preferably 100 μm or more and 400 μm or less. Further, when the substrate 100 has flexibility, a bent portion 102 may be provided.

The insulating layer 141 is provided on the substrate 100 and has a function as a base film. This makes it possible to suppress the diffusion of impurities, typically alkali metals, water, hydrogen, etc., from the substrate 100 into the semiconductor layer 142.

The semiconductor layer 142 is provided on the insulating layer 141. For the semiconductor layer 142, silicon, an oxide semiconductor, an organic semiconductor, or the like is used.

The gate insulating layer 143 is provided on the insulating layer 141 and the semiconductor layer 142. Silicon oxide, silicon oxynitride, silicon nitride or other high dielectric constant inorganic materials are used for the gate insulating layer 143.

The gate electrode 145a is provided on the gate insulating layer 143. The gate electrode 145a is connected to a scanning line (not shown). The gate electrode 145a and the capacitance electrode 145b are also provided on the gate insulating layer 143. Both the gate electrode 145a and the capacitive electrode 145b are formed of a conductive material selected from tantalum, tungsten, titanium, molybdenum, aluminum and the like. The gate electrode 145a and the capacitance electrode 145b may have a single-layer structure or a laminated structure of the above-mentioned conductive material.

The insulating layer 149 is made of the same material as the gate insulating layer 143, and is provided on the gate insulating layer 143, the gate electrode 145a, and the capacitive electrode 145b. The insulating layer 149 may be a single layer or a laminated structure of the above materials.

The source / drain electrode 147a is provided on the insulating layer 149. The source / drain electrode 147a is connected to the signal line 147b. For the source / drain electrode 147a, the same material as that given as a material example of the gate electrode 145a is used. The source / drain electrode 147a may be made of the same material as the gate electrode 145a, or may be made of a different material. In addition to the source / drain electrode 147a, other wiring is also formed by using the same conductive material, so that low resistance, good bondability with the semiconductor layer 142, and the like are required.

The pixel electrode 155 has a function as an anode of the display element 130. Further, the pixel electrode 155 preferably has a property of reflecting light. The former function is preferably an oxide conductive material such as indium tin oxide (ITO) or indium zinc oxide (IZO), and the latter function is preferable to a conductive material having high surface reflectivity such as aluminum or silver. .. In order to achieve both of these functions, a structure is adopted in which the above-mentioned materials are laminated, specifically, an oxide conductive layer such as ITO or IZO is laminated on a conductive layer having high surface reflectivity such as aluminum or silver. ..

The organic EL layer 159 is provided on the pixel electrode 155. The organic EL layer 159 has a light emitting material such as an organic electroluminescence material.

The common electrode 160 has a function as a cathode of the display element 130. The common electrode 160 is provided so as to straddle the plurality of pixel electrodes 155 and continuously cover the pixel electrodes 155. In order to transmit the light emitted by the organic EL layer 159, the common electrode 160 is provided with a material having translucency and conductivity.

The common electrode 160 is required to have translucency, and at the same time, is required to have reflectivity for forming a microcavity with the reflective surface of the pixel electrode 155. Therefore, the common electrode 160 is formed as a semi-permeable membrane. Specifically, as the common electrode 160, a layer made of silver, magnesium, or an alloy thereof is formed with a film thickness sufficient to allow light to pass through.

An organic resin material is used for the bank layer 157 in order to cover the peripheral edge of the pixel electrode 155 and to form a smooth step at the end of the pixel electrode 155. Further, in the bank layer 157, an organic resin material containing a black pigment may be used in order to increase the contrast ratio of the displayed image.

The inorganic insulating layer 162, the organic insulating layer 164, and the inorganic insulating layer 166 are laminated in this order and have a function as a sealing layer 161. For the inorganic insulating layer 162 and the inorganic insulating layer 166, the same material as the gate insulating layer 143 is used. As the organic insulating layer 164, the same material as the insulating layer 150 and the bank layer 157 is used. The sealing layer 161 prevents impurities, particularly water, generated during manufacturing and deterioration over time from entering the light emitting element. In addition to the configuration in this embodiment, the sealing layer 161 may be a single layer or a laminated structure of three or more layers as long as the sealing performance is sufficient.

The overcoat layer 170 is provided on the bank layer 157 and the sealing layer 161. For the overcoat layer, the same material as the insulating layer 150 and the bank layer 157 is used. The overcoat layer 170 is removed from the terminal electrode 109-1. As a result, the flexible printed circuit board 108 and the terminal electrode 109-1 are connected.

The terminal portion 109 (terminal electrode 109-1) is formed at the same time as the source / drain electrode 147a. The terminal electrode 109-1 is connected to the stretched conductive layer 153.

When the display device 10 has the bent portion 102, the insulating layer 141, the gate insulating layer 143, the insulating layer 149, the insulating layer 154, and the sealing layer 161 may not be provided in the bent portion 102. This makes it easier to bend the display device 10 at the bent portion 102.

In FIG. 6, the touch sensor is provided under the large unevenness caused by the sealing layer 161 and the bank layer 157. Therefore, the electrodes and wiring of the touch sensor (for example, the conductive layer 153) are prevented from being disconnected.

(1-5. Manufacturing method of display device)
Hereinafter, a method for manufacturing the display device 10 will be described with reference to FIGS. 7 to 14.

(1-5-1. Transistor formation)
First, as shown in FIG. 7, the insulating layer 141, the semiconductor layer 142, and the gate insulating layer 143 are formed on the first surface (upper surface when viewed from the cross-sectional direction) of the substrate 100, and then the gate is formed on the gate insulating layer 143. The electrode 145a and the capacitive electrode 145b are formed. Each layer is appropriately processed into a predetermined shape by using a photolithography method, a nanoimprinting method, an inkjet method, an etching method, or the like.

A glass substrate or an organic resin substrate is used as the substrate 100. For example, when an organic resin substrate is used as the substrate 100, a polyimide substrate is used.

The insulating layer 141 is formed by using a material such as silicon oxide, silicon oxynitride, or silicon nitride. The insulating layer 141 may be a single layer or a laminated layer. The insulating layer 141 is formed by a CVD method, a spin coating method, a printing method, or the like.

When a silicon material is used as the semiconductor layer 142, for example, amorphous silicon, polycrystalline silicon, or the like is used. When an oxide semiconductor is used as the semiconductor layer 142, a metal material such as indium, gallium, zinc, titanium, aluminum, tin, or cerium is used. For example, an oxide semiconductor (IGZO) having indium, gallium, and zinc can be used. The semiconductor layer 142 is formed by a sputtering method, a vapor deposition method, a plating method, a CVD method, or the like.

As the gate insulating layer 143, an insulating film containing one or more of silicon oxide, silicon oxynitride, silicon nitride, silicon nitrous oxide, aluminum oxide, magnesium oxide, hafnium oxide and the like is used. The gate insulating layer 143 can be formed by the same method as the insulating layer 141.

The gate electrode 145a and the capacitive electrode 145b are a metal element selected from tungsten, aluminum, chromium, copper, titanium, tantalum, molybdenum, nickel, iron, cobalt, tungsten, indium, and zinc, or an alloy containing the above metal element as a component. Alternatively, it is formed by using a material such as an alloy in which the above-mentioned metal elements are combined. Further, as the gate electrode 145a and the capacitance electrode 145b, those containing nitrogen, oxygen, hydrogen or the like in the above-mentioned material may be used. For example, as the gate electrode 145a and the capacitive electrode 145b, a laminated film of molybdenum and tungsten formed by a sputtering method is used.

Next, the insulating layer 149 is formed on the gate insulating layer 143 and the gate electrode 145a. The same material and method as the gate insulating layer 143 are used for forming the insulating layer 149. For example, as the insulating layer 149, a silicon oxide film formed by a plasma CVD method is used.

Next, the source / drain electrode 147a and the signal line 147b are formed on the insulating layer 149. The same materials and methods as those for the gate electrode 145a can be used for forming the source / drain electrode 147a and the signal line 147b. The source / drain electrode 147a is formed after forming an opening in the insulating layer 149, and is connected to the source / drain region of the semiconductor layer 142.

Next, as shown in FIG. 8, the insulating layer 150 is formed on the insulating layer 149 and the source / drain electrode 147a. An organic resin (organic insulating material) such as acrylic resin, epoxy resin, and polyimide is used to form the insulating layer 150. The insulating layer 150 can be formed by a spin coating method, a printing method, an inkjet method, or the like. For example, as the insulating layer 150, an acrylic resin formed by a spin coating method can be used. At this time, the insulating layer 150 is formed to the extent that the upper surface becomes flat. The insulating layer 150 is not particularly limited, but is preferably formed with a thickness of 1 μm or more and 10 μm or less. The insulating layer 150 is processed into a predetermined shape and has an opening in the terminal portion 109.

(1-5-2. Formation of touch sensor)
Next, as shown in FIG. 9, the touch sensor 20 is formed on the insulating layer 150. First, the conductive layer 151a is formed on the insulating layer 150 having a flat surface. The conductive layer 151a can be formed by using the same method as that of the gate electrode 145a. For the conductive layer 151a, a conductive material containing oxygen such as indium zinc oxide (IZO) or indium tin oxide (ITO) is used. An oxygen-containing conductive material such as indium zinc oxide (IZO) or indium tin oxide (ITO) is desirable because it has good adhesion to the insulating layer 150 using an organic resin.

When a metal material selected from tantalum, tungsten, titanium, molybdenum, aluminum and the like is used for the conductive layer 151a, it is desirable to perform heat treatment after forming the insulating layer 150. The heat treatment temperature is not particularly limited, but is preferably 150 ° C. or higher and 300 ° C. or lower. As a result, the water contained in the insulating layer 150 is removed, and the adhesion between the insulating layer 150 and the conductive layer 151a is maintained even in the latter half of the manufacturing process of the display device 10 and after the manufacturing of the display device 10. The heat treatment may be performed after the insulating layer 154 is formed.

Further, at the same time as forming the conductive layer 151a, the capacitive electrode 151b is formed. That is, the electrode forming the touch sensor 20 and the electrode forming the capacitive element are simultaneously formed on the same layer.

Next, as shown in FIG. 10, the insulating layer 154 is formed on the insulating layer 150 and the conductive layer 151a. The insulating layer 154 is formed by using the same materials and methods as the insulating layer 149 and the gate insulating layer 143. For example, as the insulating layer 149, a silicon nitride film formed by a plasma CVD method is used. After forming the insulating layer 154, the opening 154A is formed. When the display device 10 has the bent portion 102, the insulating layer 141, the gate insulating layer 143, the insulating layer 149, and the insulating layer 154 may be removed from the bent portion 102. Further, the insulating layer 154 is removed from the terminal electrode 109-1 in order to expose the terminal electrode 109-1.

Next, as shown in FIG. 11, the conductive layer 153 is formed on the insulating layer 154. The conductive layer 153 can be formed by using the same method as that of the gate electrode 145a. A metal material selected from tantalum, tungsten, titanium, molybdenum, aluminum and the like is used for the conductive layer 153. For example, for the conductive layer 153, a titanium, aluminum, or titanium laminated film formed by a sputtering method is used. The conductive layer 153 is stretched from the display unit 103 to the terminal electrode 109-1. The conductive layer 153 comes into contact with the conductive layer 151a at the opening 154A. As a result, the first sensor electrode 153-1 is formed. At the same time, the second sensor electrode 153-2 is also formed.

(1-5-3. Formation of display element)
Next, as shown in FIG. 12, the capacitive element 121 (formed by the above-mentioned capacitive electrode 151b, the insulating layer 154 and the pixel electrode 155) and the display element 130 (the pixel electrode 155, the organic EL layer 159 and the common electrode 160) Formed), forming the bank layer 157. Each layer is appropriately processed into a predetermined shape by using a photolithography method, a nanoimprinting method, an inkjet method, an etching method, or the like.

First, a pixel electrode 155 is formed on the insulating layer 154 and the conductive layer 153 so as to be separated from the first sensor electrode 153-1. For example, a light-reflecting metal material such as aluminum (Al) or silver (Ag) may be used for the pixel electrode 155, or indium tin oxide (ITO) or indium zinc oxide (ITO) having excellent hole injection properties may be used. It may have a structure in which a transparent conductive layer made of IZO) and a light-reflecting metal layer are laminated. The pixel electrode 155 is formed by the same method as the gate electrode 145a. For example, as the pixel electrode 155, a laminated film of ITO, silver, and ITO formed by a sputtering method is used. In FIG. 12, the resistance can be reduced by forming the conductive layer 153a under the pixel electrode 155, but the conductive layer 153 does not necessarily have to be formed depending on the resistance value of the pixel electrode 155.

Next, the bank layer 157 is formed so as to cover the insulating layer 154 and the peripheral edge of the pixel electrode 155. The bank layer 157 is formed so as to have a flat surface on the insulating layer 154 and on the upper surface of the pixel electrode 155. The bank layer 157 is formed with an opening so as to expose the upper surface of the pixel electrode 155. The end of the opening of the bank layer 157 preferably has a gently tapered shape. For example, as the bank layer 157, a polyimide film formed by a spin coating method is used.

Next, the organic EL layer 159 is formed on the pixel electrode 155 and the bank layer 157. The organic EL layer 159 is formed by using a small molecule or polymer organic material. When a low molecular weight organic material is used, the organic EL layer 159 includes a light emitting layer containing a light emitting organic material, a hole injection layer and an electron injection layer so as to sandwich the light emitting layer, and a hole transport layer and electrons. It may be configured to include a transport layer or the like.

Further, the organic EL layer 159 is formed so as to overlap with at least the pixel electrode 155. The organic EL layer 159 is formed by a vacuum vapor deposition method, a printing method, a spin coating method, or the like. When the organic EL layer 159 is formed by the vacuum vapor deposition method, a shadow mask may be appropriately used to form the organic EL layer 159 while providing a region where the film is not formed. The organic EL layer 159 may be formed by using a material different from that of adjacent pixels, or the same organic EL layer 159 may be used in all the pixels.

Next, the common electrode 160 is formed so as to straddle the pixel electrode 155 and the organic EL layer 159. For the common electrode 160, a transparent conductive film such as indium tin oxide (ITO) or zinc oxide (IZO), or an alloy of silver (Ag) and magnesium can be used. Further, the common electrode 160 can be formed by a vacuum vapor deposition method or a sputtering method. For example, as the common electrode 160, an alloy film of silver (Ag) and magnesium formed by a vapor deposition method is used. As a result, a display element is formed in the opening of the bank layer 157.

(1-5-4. Formation of sealing layer)
Next, as shown in FIG. 13, the inorganic insulating layer 162, the organic insulating layer 164, and the inorganic insulating layer 166, which are the sealing layers 161 are formed in this order. The sealing layer 161 is formed so as to cover the entire surface of the display unit 103.

For the inorganic insulating layer 162 and the inorganic insulating layer 166, an insulating film containing one or more of aluminum oxide, silicon oxide, silicon nitride and the like is used. The inorganic insulating layer 162 and the inorganic insulating layer 166 are formed by using a plasma CVD method, a thermal CVD method, a vapor deposition method, a spin coating method, a spray method, or a printing method. For example, as the inorganic insulating layer 162 and the inorganic insulating layer 166, a laminated film of a silicon nitride film and a silicon oxide film formed by a plasma CVD method can be used. The film thickness of the inorganic insulating layer 162 and the inorganic insulating layer 166 may be several tens of nm or more and several μm or less.

Materials such as acrylic resin, polyimide resin, and epoxy resin can be used for the organic insulating layer 164. Further, the organic insulating layer 164 is formed by using a spin coating method, a vapor deposition method, a spray method, an inkjet method, a printing method, or the like. The film thickness of the organic insulating layer 164 is not limited, but may be, for example, several μm or more and several tens of μm or less.

(1-5-5. Formation of overcoat layer)
Next, the overcoat layer 170 is formed so as to cover the display portion 103 and the peripheral portion 104. Materials such as acrylic resin, polyimide resin, and epoxy resin can be used for the overcoat layer 170. The overcoat layer 170 is formed by the same method as the insulating layer 150. The overcoat layer 170 is partially removed from the terminal portion 109 for connection with the flexible printed substrate 108.

The display device 10 can be manufactured by using the above manufacturing method. When the above manufacturing method is used, the conductive layer 151a and the capacitive electrode 151b are formed in the same layer, so that it is not necessary to provide a new step. Therefore, it is possible to reduce the number of steps in manufacturing a display device including a touch sensor.

Here, the conventional on-cell type touch sensor manufacturing method and the touch sensor manufacturing method of the present embodiment will be compared. In the case of the conventional on-cell type touch sensor, the manufacturing method of the touch sensor may be limited. For example, the upper limit of the heat treatment temperature after forming the organic EL display element is limited to about 100 ° C. in order to prevent deterioration of the organic EL layer. In this case, the resistance of the electrodes used in the touch sensor may not be sufficiently reduced, or the dielectric strength of the insulating layer may be insufficient. Therefore, it may not be possible to sufficiently increase the detection sensitivity of the touch sensor.

However, by using this embodiment, the touchon sensor 20 can be formed before the display element 130 including the organic EL layer 159 is formed. As a result, the temperature limitation at the time of forming the electrode and the insulating layer used for the touch sensor is avoided. Therefore, the resistance of the electrodes used in the touch sensor can be reduced. By lowering the resistance of the first sensor electrode 153-1 and the second sensor electrode 153-2, the detection speed of the touch sensor is improved. Further, by lowering the resistance of the first sensor electrode 153-1 and the second sensor electrode 1532, the SN (signal-noise) ratio is improved, and as a result, the detection accuracy of the touch sensor is improved. Further, by heat-treating the insulating layer at a high temperature, impurities (for example, moisture) in the insulating layer can be reduced. Therefore, the dielectric strength of the insulating layer can be improved. Therefore, the reliability of the touch sensor can be improved. Therefore, by using this embodiment, it is possible to improve the detection accuracy and the detection speed of the touch sensor without deteriorating the performance of the display element.

<Second Embodiment>
A display device including a touch sensor different from the display device shown in the first embodiment will be described. It should be noted that the description thereof will be incorporated with respect to the same parts as those of the structure and method shown in the first embodiment.

FIG. 15 is a cross-sectional view showing a part of the touch sensor and the display element in the display device 10-1. In FIG. 15, the touch sensor 20-1 is arranged on the insulating layer 148 and includes a conductive layer 147c, an insulating layer 150, an insulating layer 152, and a conductive layer 153.

As shown in FIG. 15, the touch sensor 20-1 is arranged on the insulating layer 148. The insulating layer 148 is formed of the same material and method as the insulating layer 150. Both the insulating layer 148 and the insulating layer 150 have a flat surface. Therefore, even if the wiring (for example, the conductive layer 144 shown in FIG. 15) is arranged under the insulating layer 148, the conductive layer 147c is provided on a flat surface. This effectively prevents disconnection of the electrodes and wiring used in the touch sensor.

FIG. 16 is a cross-sectional view of the display unit 103 (pixel 101) and the peripheral portion 104 of the display device 10-1. In FIG. 16, in addition to the touch sensor 20 described above, the display device 10-1 includes a conductive layer 144, an insulating layer 148, an insulating layer 150, a display element 130, a bank layer 157, a substrate 100, a transistor 110, and a capacitive element 120. It has a capacitive element 121, a capacitive element 122, a capacitive element 123, an insulating layer 141, an insulating layer 149, a sealing layer 161 and an overcoat layer 170.

As shown in FIG. 16, in the display device 10-1, the conductive layer 147c is formed in the same layer as the source / drain electrode 147a. Therefore, an increase in the number of steps in manufacturing the display device can be suppressed.

Further, as shown in FIG. 16, by arranging the insulating layer 154 between the conductive layer 153 and the pixel electrode 155, the capacitive element 121 is formed and between the capacitive electrode 151b and the conductive layer 153. The insulating layer 152 is arranged and the capacitive element 123 is formed. Similarly, a conductive layer 144 is provided between the insulating layer 149 and the insulating layer 148. As a result, the capacitive element 122 is arranged by using the capacitive electrode 145b, the conductive layer 144, and the insulating layer 149. That is, by using this embodiment, it is possible to prevent disconnection of the electrodes and wiring of the touch sensor and increase the capacity of the pixel.

(Modification 1)
In the first embodiment of the present invention, an example in which the conductive layer 153 used for the touch sensor is arranged in a mesh shape with respect to the pixel 101 is shown, but the present invention is not limited thereto. The conductive layer 153 may be arranged in a line shape or may be arranged in a diamond shape (diamond shape) as shown in FIG.

(Modification 2)
In the present embodiment, the case of an organic EL display device is exemplified as a disclosure example, but as another application example, an electronic paper type display having a liquid crystal display device, another self-luminous display device, an electrophoresis display device, or the like is illustrated. Devices include all flat panel display devices. Needless to say, it can be applied from small to medium size to large size without any particular limitation.

(Modification 3)
In the first embodiment of the present invention, the bank layer 157 is provided on the conductive layer 153 of the touch sensor 20, but the present invention is not limited to this. For example, as shown in FIG. 18, a flattening film 156 may be newly provided on the conductive layer 153. At this time, it can be said that the flattening film 156 is arranged between the conductive layer 153 and the pixel electrode 155. The flattening film 156 is formed by the same material and method as the insulating layer 150. This further alleviates the unevenness of the electrodes for the touch sensor.

(Modification example 4)
Further, as shown in FIG. 19, a shielding electrode 180 and a flattening film 158 may be further provided on the flattening film 156. At this time, the shielding electrode 180 is located between the conductive layer 153 and the common electrode 160. By providing the shielding electrode 180, it is possible to prevent the detection sensitivity from being lowered even when a parasitic capacitance is generated between the pixel electrode 155 or the common electrode 160 and the conductive layer 153. It is desirable that the same potential as that of the conductive layer 153 is applied to the shielding electrode 180 when driving the touch sensor. This makes it possible to further increase the detection sensitivity of the touch sensor.

(Modification 5)
In the first embodiment of the present invention, the first sensor electrode 153-1 and the second sensor electrode 153-2 are both provided on the insulating layer 154, but the present invention is not limited thereto. FIG. 20 is a top view of the touch sensor 20-4. FIG. 21 is a cross-sectional view of the touch sensor 20-3 between A1 and A2. As shown in FIGS. 20 and 21, the conductive layer 151a may have a function as a first sensor electrode, and the conductive layer 153 may have a function as a second sensor electrode. At this time, the first sensor electrode and the second sensor electrode are provided on different layers. This prevents a short circuit due to contact between the first sensor electrode and the second sensor electrode.

(Modification 6)
In the first embodiment of the present invention, an example in which the intersecting portions of the touch sensor 20 are superimposed on the signal line 147 is shown, but the present invention is not limited to this. FIG. 22 is a cross-sectional view of the display device 10-6. As shown in FIG. 22, the intersecting portion of the touch sensor 20 may be arranged so as to overlap with a part of the transistor 110. At this time, the signal line 147b may be arranged so as to overlap with the display element 130. This makes it possible to arrange each component at a high density.

It should be noted that, in the scope of the idea of the present invention, those skilled in the art can come up with various modified examples and modified examples, and it is understood that these modified examples and modified examples also belong to the scope of the present invention. .. For example, a person skilled in the art appropriately adds, deletes, or changes the design of each of the above-described embodiments, or adds, omits, or changes the conditions of the process, which is the gist of the present invention. Is included in the scope of the present invention as long as it is provided.

10 ... Display device, 20 ... Touch sensor, 100 ... Board, 103 ... Display unit, 104 ... Peripheral part, 105 ... Drive circuit, 106 ... Drive circuit, 108. Flexible printed board, 109 ... Terminal, 110 ... Transistor, 120 ... Capacitive element, 121 ... Capacitive element, 130 ... Display element, 132 ... Drive transistor, 134 ... -Selection transistor, 136 ... light emitting element, 138 ... holding capacity, 141 ... insulating layer, 142 ... semiconductor layer, 143 ... gate insulating layer, 145a ... gate electrode, 145b ... Capacitive electrode, 147 ... source / drain electrode, 149 ... insulating layer, 150 ... insulating layer, 151a ... conductive layer, 152 ... insulating layer, 153 ... conductive layer, 154. Insulating layer, 155 ... pixel electrode, 156 ... flattening film, 157 ... bank layer, 158 ... flattening film, 159 ... organic EL layer, 160 ... common electrode, 161 ... Sealing layer, 162 ... Inorganic insulating layer, 164 ... Organic insulating layer, 166 ... Inorganic insulating layer, 180 ... Shielding electrode

Claims (11)

A transistor in which a semiconductor layer, a gate insulating layer, a gate electrode, an insulating layer, and a source / drain electrode are arranged in order from the lower layer on a substrate.
A first insulating layer that covers the source / drain electrodes from above,
The first conductive layer on the first insulating layer and
The first insulating layer and the second insulating layer on the first conductive layer,
A first sensor electrode that partially overlaps the first conductive layer on the second insulating layer,
Pixel electrodes arranged apart from the first sensor electrode on the second insulating layer,
The light emitting layer on the pixel electrode and
With the common electrode on the light emitting layer,
A third insulating layer disposed on the second insulating layer and the first sensor electrode, covering the peripheral edge of the pixel electrode and exposing the inner region of the pixel electrode, and the like.
The first sensor electrode is connected to the first conductive layer at an opening penetrating the second insulating layer.
The first sensor electrode is a display device having a mesh-like pattern surrounding the pixel electrode . The display device according to claim 1, further comprising a second sensor electrode arranged on the same surface as the first sensor electrode and separated from the first sensor electrode. It has a plurality of the first sensor electrodes arranged apart from each other in one direction.
The display device according to claim 2 , wherein the plurality of the first sensor electrodes are connected to each other by the first conductive layer. The first sensor electrode is stretched in the first direction, and the second sensor electrode is stretched in the second direction intersecting the first direction.
The display device according to claim 3 , wherein the first sensor electrode intersects the second sensor electrode via the first conductive layer and the second insulating layer. The first insulating layer has a flat surface and has a flat surface.
The display device according to any one of claims 1 to 4 , wherein the third insulating layer has a flat surface on the upper surfaces of the first conductive layer and the first sensor electrode. The display device according to claim 5 , wherein the second insulating layer has a flat surface. A capacitive electrode arranged on the same surface as the first conductive layer and separated from the first conductive layer is included.
The display device according to any one of claims 1 to 6 , wherein the capacitive electrode is superimposed on the pixel electrode. Including additional shielding electrodes,
The display device according to any one of claims 1 to 7 , wherein the shielding electrode is located between the first sensor electrode and the common electrode in a cross-sectional view. The display device according to claim 8 , wherein the first sensor electrode and the shielding electrode have the same potential when a detection element including the first sensor electrode is driven. The display device according to any one of claims 1 to 9 , wherein the first insulating layer contains an organic resin. The display device according to claim 10 , wherein the first conductive layer is a conductive material containing oxygen.

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