JP6702781B2 - Display device - Google Patents

Description

One embodiment of the present invention relates to a display device.

Note that one embodiment of the present invention is not limited to the above technical field. The technical field of one embodiment of the present invention disclosed in this specification and the like includes a semiconductor device, a display device, a light-emitting device, a power storage device, a storage device, an electronic device, a lighting device, an input device, an input/output device, and a driving method thereof. , Or their manufacturing method can be mentioned as an example.

Note that in this specification and the like, a semiconductor device generally means a device that can function by utilizing semiconductor characteristics. A transistor, a semiconductor circuit, an arithmetic device, a memory device, and the like are one mode of a semiconductor device. Further, the image pickup device, the electro-optical device, the power generation device (including a thin film solar cell, an organic thin film solar cell, and the like) and the electronic device may include a semiconductor device.

As one of display devices, there is a liquid crystal display device including a liquid crystal element. For example, an active matrix liquid crystal display device in which pixel electrodes are arranged in a matrix and a transistor is used as a switching element connected to each pixel electrode has attracted attention.

For example, an active matrix type liquid crystal display device using a transistor having a metal oxide as a channel forming region as a switching element connected to each pixel electrode is known. (Patent Document 1 and Patent Document 2)

The active matrix type liquid crystal display device is roughly classified into two types, a transmission type and a reflection type.

A transmissive liquid crystal display device uses a backlight such as a cold cathode fluorescent lamp or an LED (Light Emitting Diode), and the light from the backlight is transmitted through the liquid crystal by utilizing the optical modulation function of the liquid crystal, and thus the liquid crystal display device is used. An image is displayed by selecting a state of being output to the outside and a state of not being output, displaying bright and dark, and combining them.

In addition, the reflection type liquid crystal display device utilizes the optical modulation action of liquid crystal to output external light, that is, the incident light is reflected to the pixel electrode and is output to the outside of the device, and the incident light is not output to the outside of the device. By selecting a state, displaying light and dark, and combining them, an image is displayed. The reflective liquid crystal display device has an advantage that it consumes less power than a transmissive liquid crystal display device because it does not use a backlight.

JP, 2007-123861, A JP, 2007-96055, A

In electronic devices to which the display device is applied, it is required to reduce power consumption. In particular, in devices using a battery as a power source, such as mobile phones, smartphones, tablet terminals, smart watches, and notebook personal computers, the power consumption of the display device accounts for a large proportion, and thus low power consumption of the display device is required. Has been.

In addition, portable electronic devices are required to have high visibility in both an environment with strong external light and an environment with little external light.

Further, in a portable electronic device, the display device may be broken when it is dropped or put in a pocket of pants or the like. Therefore, a display device provided in an electronic device is required to be light and resistant to breakage.

One object of one embodiment of the present invention is to reduce power consumption of a display device. Another object is to improve the display quality of a display device. Another object is to display an image with high display quality regardless of the usage environment. Another object is to provide a display device which is light and hard to break. Another object is to provide a display device that can be bent.

Another object is to provide a method for manufacturing a display device with high productivity.

One embodiment of the present invention is a display device including a first display panel, a second display panel, and a first adhesive layer. The first display panel includes a first insulating layer, a reflective liquid crystal element, and a first transistor. The second display panel includes a second insulating layer, a light emitting element, and a second transistor. The adhesive layer is provided between the first insulating layer and the second insulating layer. The first transistor is provided on a surface of the first insulating layer opposite to the first adhesive layer, and the second transistor is provided on a surface of the second insulating layer opposite to the first adhesive layer. It is provided in. A channel is formed in the oxide semiconductor in the first transistor and the second transistor. The liquid crystal element has a function of reflecting light to the side opposite to the first insulating layer, and the light emitting element has a function of emitting light to the second insulating layer side.

Further, in the above, it is preferable that a first resin layer be provided between the first adhesive layer and the first insulating layer. Further, it is preferable to have a second resin layer between the first adhesive layer and the second insulating layer. At this time, it is preferable that the first resin layer and the second resin layer have a region having a thickness of 0.1 μm or more and 3 μm or less.

Further, in the above description, it is preferable that the first resin layer has a first opening and the second resin layer has a second opening. At this time, the light emitting element preferably has a function of emitting light through the first opening and the second opening.

Further, in the above, it is preferable to have a third resin layer. At this time, the liquid crystal element and the first transistor are located between the third resin layer and the first insulating layer. Further, the third resin layer preferably has a third opening, and the light emitting element preferably emits light through the third opening. Further, at this time, it is preferable that the third opening has a portion overlapping with the liquid crystal element, and the liquid crystal element preferably reflects light through the third opening. Further, the third resin layer preferably has a thickness of 0.1 μm or more and 3 μm or less.

Further, in the above, it is preferable to have a first substrate, a second substrate, a second adhesive layer, and a third adhesive layer. At this time, the first display panel and the second display panel are located between the first substrate and the second substrate. The second adhesive layer is located between the first substrate and the first display panel, and the third adhesive layer is located between the second substrate and the second display panel. At this time, it is preferable that each of the first substrate and the second substrate contains a resin.

In the above, the first transistor preferably has a first source electrode, a first drain electrode, and a first semiconductor layer. In addition, the second transistor preferably has a second source electrode, a second drain electrode, and a second semiconductor layer.

At this time, the first source electrode and the first drain electrode are provided in contact with an upper surface and a side end portion of the first semiconductor layer, and the second source electrode and the second drain electrode are provided in the second semiconductor layer. It is preferably provided in contact with the upper surface and side edges of the layer.

Alternatively, a first insulating layer that covers a part of the upper surface of the first semiconductor layer and a side end portion is provided, and a second insulating layer that covers a part of the upper surface of the second semiconductor layer and a side end portion is provided. Preferably. Further, the first source electrode and the first drain electrode are provided over the first insulating layer and electrically connected to the first semiconductor layer through the opening provided in the first insulating layer. The second source electrode and the second drain electrode are provided on the second insulating layer and electrically connected to the second semiconductor layer through an opening provided in the second insulating layer. Is preferred.

Alternatively, the first source electrode and the first drain electrode are provided in contact with the top surface and the side edge portion of the first semiconductor layer, and the second source layer and the second drain electrode cover a part of the top surface and the side edge portion of the second semiconductor layer. Second insulating layer, the second source electrode and the second drain electrode are provided on the second insulating layer, and with the second semiconductor layer through an opening provided in the second insulating layer. It is preferably electrically connected.

Alternatively, the semiconductor device includes a first insulating layer which covers a part of an upper surface of the first semiconductor layer and a side edge portion, and the first source electrode and the first drain electrode are provided over the first insulating layer, Further, the second source electrode and the second drain electrode are electrically connected to the first semiconductor layer through an opening provided in the first insulating layer, and the second source electrode and the second drain electrode are an upper surface and a side end portion of the second semiconductor layer. Is preferably provided in contact with.

The first transistor has a first gate electrode and a second gate electrode, and the first gate electrode and the second gate electrode are provided to face each other with the first semiconductor layer interposed therebetween. Preferably. The second transistor has a third gate electrode and a fourth gate electrode, and the third gate electrode and the fourth gate electrode are provided to face each other with the second semiconductor layer interposed therebetween. Preferably.

According to one embodiment of the present invention, power consumption of the display device can be reduced. Alternatively, the display quality of the display device can be improved. Alternatively, it is possible to provide a display device that displays an image with high display quality regardless of the use environment. Alternatively, it is possible to provide a display device which is light and hard to break. Alternatively, a bendable display device can be provided. Alternatively, a method for manufacturing a display device with high productivity can be provided.

3 illustrates a structural example of a display device according to an embodiment. 6A to 6C are diagrams illustrating a method for manufacturing a display device according to an embodiment. 6A to 6C are diagrams illustrating a method for manufacturing a display device according to an embodiment. 6A to 6C are diagrams illustrating a method for manufacturing a display device according to an embodiment. 6A to 6C are diagrams illustrating a method for manufacturing a display device according to an embodiment. 6A to 6C are diagrams illustrating a method for manufacturing a display device according to an embodiment. 6A to 6C are diagrams illustrating a method for manufacturing a display device according to an embodiment. 6A to 6C are diagrams illustrating a method for manufacturing a display device according to an embodiment. 6A to 6C are diagrams illustrating a method for manufacturing a display device according to an embodiment. 6A to 6C are diagrams illustrating a method for manufacturing a display device according to an embodiment. 3 illustrates a structural example of a display device according to an embodiment. 3 illustrates a structural example of a display device according to an embodiment. 3 illustrates a structural example of a display device according to an embodiment. 3 illustrates a structural example of a display device according to an embodiment. 3 illustrates a structural example of a display device according to an embodiment. FIG. 6 is a circuit diagram of a display device according to an embodiment. FIG. 6 is a circuit diagram of a display device according to an embodiment. 3 illustrates a structural example of a display device according to an embodiment. 3 illustrates a structural example of a display device according to an embodiment. 3 illustrates a structural example of a display device according to an embodiment. 3 illustrates a structural example of a display device according to an embodiment. 3 illustrates a structural example of a display device according to an embodiment. 6 is a configuration example of a display module according to the embodiment. An electronic device according to an embodiment.

Embodiments will be described in detail with reference to the drawings. However, the present invention is not limited to the following description, and it is easily understood by those skilled in the art that modes and details can be variously changed without departing from the spirit and scope of the present invention. Therefore, the present invention should not be construed as being limited to the description of the embodiments below.

Note that in the structures of the invention described below, the same reference numerals are commonly used in different drawings for the same portions or portions having similar functions, and repeated description thereof is omitted. Further, when referring to the same function, the hatch pattern may be the same and may not be given a reference numeral.

Note that in each drawing described in this specification, the size, the layer thickness, or the region of each component is exaggerated for clarity in some cases. Therefore, it is not necessarily limited to that scale.

Note that the ordinal numbers such as “first” and “second” in this specification and the like are added to avoid confusion among components, and are not numerically limited.

A transistor is a kind of semiconductor element, and can realize amplification of current or voltage, switching operation for controlling conduction or non-conduction, and the like. The transistor in this specification includes an IGFET (Insulated Gate Field Effect Transistor) and a thin film transistor (TFT: Thin Film Transistor).

(Embodiment 1)
In this embodiment, a display device of one embodiment of the present invention and a manufacturing method thereof will be described.

A display device according to one embodiment of the present invention includes a first display panel provided with a first pixel having a reflective liquid crystal element and a second display panel provided with a second pixel having a light-emitting element. However, it has a configuration in which it is bonded via an adhesive layer. The reflective liquid crystal element can express gradation by controlling the amount of reflected light. The light emitting element can express gradation by controlling the amount of emitted light.

The display device, for example, performs display using only reflected light, performs display using only light from the light emitting element, and performs display using both reflected light and light from the light emitting element. It can be carried out.

The first display panel is provided on the viewing side, and the second display panel is provided on the side opposite to the viewing side. The first display panel has the first resin layer located closest to the adhesive layer. The second display panel has a second resin layer located closest to the adhesive layer.

Further, it is preferable that the third resin layer is provided on the display surface side of the first display panel and the fourth resin layer is provided on the back surface side (the side opposite to the display surface side) of the second display panel. As a result, the display device can be made extremely light, and the display device can be made hard to break.

The first to fourth resin layers (hereinafter also collectively referred to as resin layers) are characterized in being extremely thin. More specifically, each thickness is preferably 0.1 μm or more and 3 μm or less. Therefore, it is possible to reduce the thickness even when the two display panels are stacked. Further, even when the resin layer is arranged on the path of the light emitted by the light emitting element of the second pixel, the resin layer is thin, so that the light absorption is suppressed and the light can be extracted with higher efficiency. Therefore, the power consumption can be reduced.

The resin layer can be formed as follows, for example. That is, a low-viscosity thermosetting resin material is applied on a supporting substrate and cured by heat treatment to form a resin layer. Then, a structure is formed on the resin layer. Then, peeling is performed between the resin layer and the supporting substrate to expose one surface of the resin layer.

When the support substrate and the resin layer are peeled off, irradiation with laser light can be mentioned as a method for reducing the adhesion between them. For example, it is preferable to irradiate the laser light by using a linear laser as the laser light and scanning this. As a result, the process time for increasing the area of the support substrate can be shortened. An excimer laser having a wavelength of 308 nm can be preferably used as the laser light.

As a material that can be used for the resin layer, a thermosetting polyimide is typically mentioned. It is particularly preferable to use photosensitive polyimide. Since the photosensitive polyimide is a material that is preferably used for a flattening film of a display panel and the like, the forming device and the material can be shared. Therefore, a new device or material is not needed to realize the structure of one embodiment of the present invention.

Further, by using a photosensitive resin material for the resin layer, it is possible to process the resin layer by performing exposure and development processing. For example, an opening can be formed or an unnecessary portion can be removed. Further, by optimizing the exposure method and the exposure conditions, it becomes possible to form an uneven shape on the surface. For example, an exposure technique using a halftone mask or a graytone mask, a multiple exposure technique, or the like may be used.

A non-photosensitive resin material may be used. At this time, it is also possible to use a method of forming a resist mask or a hard mask on the resin layer to form an opening or an uneven shape.

Further, it is preferable to partially remove the resin layer located on the path of the light from the light emitting element. That is, the first resin layer and the second resin layer are provided with openings overlapping with the light emitting element. As a result, it is possible to suppress a decrease in color reproducibility and a decrease in light extraction efficiency due to absorption of a part of light from the light emitting element in the resin layer.

Alternatively, the recess may be formed in the resin layer so that the portion of the resin layer located on the path of the light from the light emitting element is thinner than the other portions. That is, the resin layer may have two portions having different thicknesses, and the thin portion may overlap the light emitting element. Also with this configuration, the absorption of light from the light emitting element by the resin layer can be reduced.

Further, when the first display panel has the third resin layer on the display surface side, it is preferable to provide an opening overlapping with the light emitting element as described above. Thereby, color reproducibility and light extraction efficiency can be further improved.

Further, when the first display panel has the third resin layer, it is preferable to remove a part of the third resin layer located on the light path in the reflective liquid crystal element. That is, the third resin layer is provided with an opening overlapping with the reflective liquid crystal element. Thereby, the reflectance of the reflective liquid crystal element can be improved. Further, it is possible to prevent the light reflected from the reflective liquid crystal element from being colored.

As a method of forming the opening in the resin layer, for example, the following method can be used. That is, a light absorption layer is formed over a supporting substrate, a resin layer having an opening is formed over the light absorption layer, and a light-transmitting layer that covers the opening is formed. The light absorption layer is a layer that absorbs light and is heated to release a gas such as hydrogen or oxygen. Therefore, by irradiating light from the supporting substrate side and releasing gas from the light absorbing layer, the adhesiveness between the interface between the light absorbing layer and the supporting substrate or between the light absorbing layer and the translucent layer decreases. , Peeling can occur. Alternatively, the light absorption layer itself can be broken and peeled off.

Alternatively, the following method can be used. That is, the opening portion of the resin layer is partially thinned, and the support substrate and the resin layer are separated by the method described above. When the resin layer is thinned by performing plasma treatment or the like on the peeled surface of the resin layer, an opening can be formed in a thin portion of the resin layer.

In addition, each of the first pixel and the second pixel preferably has a transistor. Further, an oxide semiconductor is preferably used as a semiconductor forming a channel of the transistor. Even when the maximum temperature of an oxide semiconductor in a manufacturing process of a transistor is lowered (eg, 400° C. or lower, preferably 350° C. or lower), a high on-state current can be realized and high reliability can be secured. When an oxide semiconductor is used, high heat resistance is not required as a material used for the resin layer located on the formation surface side of the transistor, so that the range of material selection can be widened. For example, it can also serve as a resin material used as a flattening film.

Here, for example, when low temperature polysilicon (Low Temperature Poly-Silicon) (LTPS) is used, although a high field effect mobility can be obtained, a laser crystallization step, a crystallization pretreatment bake step, and an impurity activation A bake step for conversion is required, and the maximum temperature required for a transistor manufacturing step is higher than that in the case of using the above oxide semiconductor (eg, 500° C. or higher, 550° C. or higher, or 600° C. or higher). Therefore, high heat resistance is required for the resin layer located on the formation surface side of the transistor. Further, in the laser crystallization step, since the resin layer is also irradiated with the laser, the resin layer needs to be formed relatively thick (for example, 10 μm or more, or 20 μm or more).

On the other hand, when an oxide semiconductor is used, a special material having high heat resistance is not needed and it is necessary to form a thick material, so that the cost ratio of the resin layer to the entire display panel can be reduced.

Further, the oxide semiconductor has a wide band gap (for example, 2.5 eV or more, or 3.0 eV or more) and has a property of transmitting light. Therefore, in the step of peeling the supporting substrate and the resin layer, even if the laser light is applied to the oxide semiconductor, it is difficult to absorb the laser light, so that the influence on the electrical characteristics can be suppressed. Therefore, the resin layer can be formed thin as described above.

One embodiment of the present invention is a thin resin layer formed using a low-viscosity photosensitive resin material typified by photosensitive polyimide, and an oxide semiconductor capable of realizing a transistor with excellent electrical characteristics even at low temperature. By combining and, it is possible to realize a display device having extremely excellent productivity.

Subsequently, the configuration of the pixel will be described. A plurality of the first pixels and the second pixels are arranged in a matrix to form a display portion. Further, it is preferable that the display device has a first driving unit that drives the first pixel and a second driving unit that drives the second pixel. It is preferable that the first drive unit is provided on the first display panel and the second drive unit is provided on the second display panel.

Further, it is preferable that the first pixel and the second pixel are arranged in the display area at the same cycle. Further, the first pixel and the second pixel are preferably arranged in a mixed manner in the display area of the display device. Thereby, as will be described later, an image displayed only by the plurality of first pixels, an image displayed only by the plurality of second pixels, and both the plurality of first pixels and the plurality of second pixels Each of the images displayed by can be displayed in the same display area.

Here, it is preferable that the first pixel is configured by one pixel that exhibits white (W), for example. Further, it is preferable that the second pixel has sub-pixels that respectively present light of three colors of red (R), green (G), and blue (B). Alternatively, in addition to this, a sub pixel which exhibits white (W) or yellow (Y) light may be included. By arranging the first pixel and the second pixel in the same cycle as described above, the area of the first pixel can be increased and the aperture ratio of the first pixel can be increased.

Note that the first pixel may include sub-pixels that respectively present light of three colors of red (R), green (G), and blue (B), and in addition to this, white (W) or It may have a sub-pixel that exhibits yellow (Y) light.

One embodiment of the present invention is a first mode in which an image is displayed in a first pixel, a second mode in which an image is displayed in a second pixel, and an image is displayed in a first pixel and a second pixel. The third mode can be switched.

In the first mode, since the display can be performed using only the reflected light, the light source is unnecessary. Therefore, the drive mode has extremely low power consumption. For example, it is effective when the illuminance of external light is sufficiently high and the external light is white light or light in the vicinity thereof. The first mode is a display mode suitable for displaying character information such as books and documents.

In the second mode, since display can be performed using light from the light source, extremely vivid display can be performed regardless of the illuminance or chromaticity of external light. For example, it is effective when the illuminance of external light is extremely low, such as at night or in a dark room. In addition, when the external light is dark, the user may feel dazzling when performing bright display. In order to prevent this, it is preferable to perform display with suppressed brightness in the second mode. Further, this can reduce power consumption in addition to suppressing glare. The second mode is a mode suitable for displaying vivid images and smooth moving images.

In the third mode, display can be performed using both the light from the light source and the reflected light. Specifically, the light emitted by the first pixel and the light emitted by the second pixel adjacent to the first pixel are mixed to drive so as to express one color. It is possible to display more vividly than in the first mode and to suppress power consumption more than in the second mode. For example, it is effective when the illuminance of external light is relatively low, such as under indoor lighting, in the morning or in the evening, and when the chromaticity of external light is not white.

Next, transistors that can be used for the first display panel and the second display panel will be described. The transistor provided in the first pixel of the first display panel and the transistor provided in the second pixel of the second display panel may be transistors having the same structure or different transistors. Good.

An example of the transistor configuration is a bottom-gate transistor. The bottom-gate transistor has a gate electrode below the semiconductor layer (on the surface where the semiconductor layer is formed). Further, for example, the source electrode and the drain electrode are provided in contact with the upper surface and the side end portion of the semiconductor layer.

Further, as another structure of the transistor, for example, a top-gate transistor can be given. The top-gate transistor has a gate electrode above the semiconductor layer (on the side opposite to the formation surface). In addition, for example, the first source electrode and the first drain electrode are provided over an insulating layer which covers part of an upper surface and side edges of the semiconductor layer, and the semiconductor layer is provided through an opening provided in the insulating layer. It is characterized in that it is electrically connected to.

Further, it is preferable that the transistor include a first gate electrode and a second gate electrode which are provided to face each other with the semiconductor layer interposed therebetween.

Here, in the display device of one embodiment of the present invention, the transistor of the first display panel and the reflective electrode of the liquid crystal element are formed in the first resin layer on the adhesive layer side, and the transistor and the light emission of the second display panel are formed. The element is formed in the second resin layer on the adhesive layer side. Therefore, as the light emitting element, a bottom emission type light emitting element that emits light to the formation surface side can be preferably used. As a result, the light emitting surface of the light emitting element can be arranged at a position close to the display surface side, and a display device having excellent viewing angle characteristics can be realized.

Hereinafter, more specific examples of the display device of one embodiment of the present invention will be described with reference to the drawings.

[Configuration example 1]
FIG. 1 shows a schematic cross-sectional view of the display device 10. The display device 10 has a configuration in which the display panel 100 and the display panel 200 are bonded together by the adhesive layer 50. Further, the display device 10 has a substrate 11 on the back side (the side opposite to the viewing side) and a substrate 12 on the front side (viewing side).

The display panel 100 includes a transistor 110 and a light emitting element 120 between the resin layer 101 and the substrate 11. The display panel 200 includes a transistor 210 and a liquid crystal element 220 between the resin layer 201 and the resin layer 202. The substrate 11 is adhered by an adhesive layer 151 that covers the light emitting element 120. The resin layer 202 is bonded to the substrate 12 via the adhesive layer 52.

Further, each of the resin layer 101, the resin layer 201, and the resin layer 202 has an opening. A region 31 illustrated in FIG. 1 is a region overlapping with the light-emitting element 120 and a region overlapping with the opening portion of the resin layer 101, the opening portion of the resin layer 201, and the opening portion of the resin layer 202.

[Display panel 100]
The resin layer 101 is provided with a transistor 110, a light emitting element 120, an insulating layer 131, an insulating layer 132, an insulating layer 133, an insulating layer 134, an insulating layer 135, and the like.

The transistor 110 includes a conductive layer 111 which functions as a gate electrode, a part of an insulating layer 132 which functions as a gate insulating layer, a semiconductor layer 112, a conductive layer 113a which functions as one of a source electrode and a drain electrode, and a source electrode. Or a conductive layer 113b which functions as the other of the drain electrodes.

The semiconductor layer 112 preferably contains an oxide semiconductor.

The insulating layer 133 and the insulating layer 134 are provided so as to cover the transistor 110. The insulating layer 134 functions as a planarization layer.

The light emitting element 120 has a structure in which a conductive layer 121, an EL layer 122, and a conductive layer 123 are stacked. The conductive layer 121 has a function of transmitting visible light, and the conductive layer 123 has a function of reflecting visible light. Therefore, the light emitting element 120 is a bottom emission type (also referred to as bottom emission type) light emitting element that emits light to the formation surface.

The conductive layer 121 is electrically connected to the conductive layer 113b through openings provided in the insulating layer 134 and the insulating layer 133. The insulating layer 135 covers the end portion of the conductive layer 121 and has an opening so that part of the surface of the conductive layer 121 is exposed. The EL layer 122 and the conductive layer 123 are sequentially provided so as to cover the exposed portions of the insulating layer 135 and the conductive layer 121.

An insulating layer 124 is provided so as to cover the conductive layer 123. The insulating layer 124 functions as a barrier layer that suppresses diffusion of impurities such as moisture into the light emitting element 120. The insulating layer 124 preferably has an inorganic insulating film. For example, the inorganic insulating film may be used as a single layer or a plurality of inorganic insulating films may be laminated. Further, a laminated structure of an inorganic insulating film and an organic insulating film may be used.

Since the insulating layer 124 is provided, it is not necessary to use a material having a high barrier property for the adhesive layer 151 and the substrate 11, so that the degree of freedom in selecting a material can be increased. It is also possible to make the adhesive layer 151 and the substrate 11 thin.

Here, an opening is provided in the resin layer 101 located on the viewing side of the light emitting element 120. The light emitting element 120 is arranged so as to overlap the opening. The insulating layer 131 is provided so as to cover the opening of the resin layer 101. The insulating layer 131 is provided to cover the opening of the resin layer 101. The portion of the insulating layer 131 that overlaps the opening of the resin layer 101 is in contact with the adhesive layer 50.

[Display panel 200]
The resin layer 201 is provided with a transistor 210, a conductive layer 221, an alignment film 224a, an insulating layer 231, an insulating layer 232, an insulating layer 233, an insulating layer 234, and the like. The resin layer 202 is provided with an insulating layer 204, a conductive layer 223, an alignment film 224b, and the like. The liquid crystal 222 is sandwiched between the alignment films 224a and 224b. The resin layer 201 and the resin layer 202 are adhered by an adhesive layer in a region (not shown).

The transistor 210 includes a conductive layer 211 that functions as a gate electrode, part of an insulating layer 232 that functions as a gate insulating layer, a semiconductor layer 212, a conductive layer 213a that functions as one of a source electrode and a drain electrode, and a source electrode. Or a conductive layer 213b functioning as the other of the drain electrodes.

The semiconductor layer 212 preferably contains an oxide semiconductor.

The insulating layer 233 and the insulating layer 234 are provided so as to cover the transistor 210. The insulating layer 234 functions as a planarization layer.

The liquid crystal element 220 includes a conductive layer 221, a conductive layer 223, and a liquid crystal 222 positioned between them. The conductive layer 221 has a function of reflecting visible light, and the conductive layer 223 has a function of transmitting visible light. Therefore, the liquid crystal element 220 is a reflective liquid crystal element.

The conductive layer 211 is electrically connected to the conductive layer 213b through an opening provided in the insulating layer 234 and the insulating layer 233. The alignment film 224a is provided so as to cover the surfaces of the conductive layer 211 and the insulating layer 234.

On the resin layer 201 side of the resin layer 202, a conductive layer 223 and an alignment film 224b are stacked and provided. Note that the insulating layer 204 is provided between the resin layer 202 and the conductive layer 223. Further, a coloring layer for coloring the reflected light of the liquid crystal element 220 may be provided. Further, a light-blocking layer that suppresses color mixture between adjacent pixels may be provided.

The insulating layer 231 is provided to cover the opening of the resin layer 201. The portion of the insulating layer 231 that overlaps the opening of the resin layer 202 is provided in contact with the adhesive layer 50. The insulating layer 204 is provided so as to cover the opening of the resin layer 202. The portion of the insulating layer 204 that overlaps the opening of the resin layer 202 is provided in contact with the adhesive layer 52.

[Display device 10]
The display device 10 has a portion where the light emitting element 120 does not overlap with the reflective liquid crystal element 220 when viewed from the top surface. As a result, as shown in FIG. 1, the light emitting element 120 emits the light emission 21 colored by the coloring layer 152 to the viewing side. Further, in the liquid crystal element 220, the reflected light 22 in which the external light is reflected by the conductive layer 221 is emitted through the liquid crystal 222.

The light emission 21 emitted from the light emitting element 120 passes through the opening of the resin layer 101, the opening of the resin layer 201, and the opening of the resin layer 202, and is emitted to the viewing side. Therefore, even when the resin layer 101, the resin layer 201, and the resin layer 202 absorb a part of visible light, these resin layers do not exist on the optical path of the light emission 21, so that the light extraction efficiency and the color reproduction are reduced. It is possible to make the quality high.

The substrate 12 functions as a polarizing plate or a circularly polarizing plate. Alternatively, a polarizing plate or a circularly polarizing plate may be provided outside the substrate 12.

Although the display panel 200 does not have a colored layer and does not perform color display here, a colored layer may be provided on the resin layer 202 side so that color display is possible.

Further, although glass substrates and the like may be used for the substrates 11 and 12, it is preferable to use a material containing resin. If the resin material is used, the weight of the display device 10 can be reduced as compared with the case where glass or the like is used even if the resin material has the same thickness. Further, it is preferable to use a material that is thin enough to have flexibility (including a glass substrate or the like) because the weight can be further reduced. Further, by using the resin material, it is possible to improve the impact resistance of the display device and realize a display device which is not easily broken.

In addition, since the substrate 11 is a substrate located on the side opposite to the viewing side, it does not have to have a property of transmitting visible light. Therefore, a metal material can also be used. Since the metal material has high thermal conductivity and can easily conduct heat to the entire substrate, it is possible to suppress a local temperature rise of the display device 10.

The above is the description of the configuration example.

[Example of manufacturing method]
Hereinafter, an example of a method for manufacturing the display device 10 illustrated in FIG. 1 will be described with reference to the drawings.

Note that thin films (insulating films, semiconductor films, conductive films, and the like) forming a display device are formed by a sputtering method, a chemical vapor deposition (CVD) method, a vacuum evaporation method, a pulse laser deposition (PLD: Pulse Laser Deposition) method. ) Method, an atomic layer deposition (ALD: Atomic Layer Deposition) method and the like. As the CVD method, a plasma chemical vapor deposition (PECVD) method or a thermal CVD method may be used. As an example of the thermal CVD method, a metal organic chemical vapor deposition (MOCVD) method may be used.

In addition, thin films (insulating film, semiconductor film, conductive film, etc.) that make up the display device are spin-coated, dip-, spray-coated, inkjet, dispense, screen-print, offset-print, doctor knife, slit coat, roll coat, curtain coat. It can be formed by a method such as knife coating.

Further, when the thin film forming the display device is processed, it can be processed using a photolithography method or the like. Alternatively, the island-shaped thin film may be formed by a film forming method using a shielding mask. Alternatively, the thin film may be processed by a nanoimprint method, a sandblast method, a lift-off method, or the like. As the photolithography method, a photosensitive resist material is applied onto a thin film to be processed, the resist mask is exposed by using a photomask, and then developed to form a resist mask, and the thin film is processed by etching or the like. There are a method of removing the resist mask and a method of forming a thin film having photosensitivity and then performing exposure and development to process the thin film into a desired shape.

In the photolithography method, the light used for exposure may be, for example, i-line (wavelength 365 nm), g-line (wavelength 436 nm), h-line (wavelength 405 nm), or light obtained by mixing these. In addition, ultraviolet light, KrF laser light, ArF laser light, or the like can be used. Further, the exposure may be performed by a liquid immersion exposure technique. As the light used for the exposure, extreme ultraviolet light (EUV) or X-ray may be used. An electron beam may be used instead of the light used for exposure. The use of extreme ultraviolet light, X-rays or electron beams is preferable because it enables extremely fine processing. Note that a photomask is not necessary when performing exposure by scanning a beam such as light or an electron beam.

For etching the thin film, a dry etching method, a wet etching method, a sandblast method, or the like can be used.

First, a method for manufacturing the display panel 100 will be described.

[Preparation of support substrate]
First, the support substrate 61 is prepared. As the supporting substrate 61, a material that is rigid enough to be easily transported and that has heat resistance to the temperature of a manufacturing process can be used. For example, a material such as glass, quartz, ceramic, sapphire, organic resin, semiconductor, metal or alloy can be used. As the glass, for example, non-alkali glass, barium borosilicate glass, aluminoborosilicate glass or the like can be used.

[Formation of Light Absorption Layer 103a]
Then, the light absorption layer 103a is formed over the supporting substrate 61 (FIG. 2A). The light absorption layer 103a is a layer that releases hydrogen, oxygen, or the like by absorbing the light 70 and generating heat in a subsequent irradiation step of the light 70.

As the light absorption layer 103a, for example, a hydrogenated amorphous silicon (a-Si:H) film from which hydrogen is released by heating can be used. The hydrogenated amorphous silicon film can be formed by, for example, a plasma CVD method containing SiH ₄ as a film forming gas. Further, in order to further contain a large amount of hydrogen, heat treatment may be performed in an atmosphere containing hydrogen after the film formation.

Alternatively, as the light absorption layer 103a, an oxide film from which oxygen is released by heating can be used. In particular, an oxide semiconductor film or an oxide conductor film is preferable because it has a narrower bandgap than an insulating film such as a silicon oxide film and easily absorbs light. Note that the oxide conductor film can be formed by increasing the defect level or the impurity level of the oxide semiconductor film. When an oxide semiconductor is used, the above-described method for forming the semiconductor layer 112 and materials that can be used for the semiconductor layer described later can be used. The oxide film can be formed by a plasma CVD method, a sputtering method, or the like in an atmosphere containing oxygen, for example. In particular, when an oxide semiconductor film is used, it is preferable that the oxide semiconductor film be formed by a sputtering method in an atmosphere containing oxygen. Further, in order to further contain oxygen, heat treatment may be performed in an atmosphere containing oxygen after the film formation.

Alternatively, an oxide insulating film may be used as the oxide film that can be used for the light absorption layer 103a. For example, a silicon oxide film, a silicon oxynitride film, an aluminum oxide film, a silicon oxynitride film, or the like can be used. For example, by forming such an oxide insulating film at a low temperature (eg, 250° C. or lower, preferably 220° C. or lower) in an atmosphere containing oxygen, an oxide insulating film containing excess oxygen can be obtained. Can be formed. For the film formation, for example, a sputtering method or a plasma CVD method can be used.

[Formation of resin layer]
Then, the resin layer 101 is formed over the light absorption layer 103a (FIG. 2B).

First, the material to be the resin layer 101 is applied onto the support substrate 61. The spin coating method is preferable because the thin resin layer 101 can be uniformly formed on a large substrate.

As another coating method, a method such as dip, spray coating, ink jet, dispense, screen printing, offset printing, doctor knife, slit coating, roll coating, curtain coating, knife coating may be used.

The material has a polymerizable monomer that exhibits thermosetting property (also referred to as thermopolymerizable property) in which polymerization proceeds by heat. Furthermore, the material preferably has photosensitivity. Further, the material preferably contains a solvent for adjusting the viscosity.

The material preferably contains a polymerizable monomer that becomes a polyimide resin, an acrylic resin, an epoxy resin, a polyamide resin, a polyimideamide resin, a siloxane resin, a benzocyclobutene resin, or a phenol resin after polymerization. That is, the formed resin layer 101 contains these resin materials. In particular, it is preferable to use a resin represented by a polyimide resin for the resin layer 101 by using a polymerizable monomer having an imide bond as the material because heat resistance and weather resistance can be improved.

The viscosity of the material used for coating is 5 cP or more and less than 500 cP, preferably 5 cP or more and less than 100 cP, and more preferably 10 cP or more and 50 cP or less. The lower the viscosity of the material, the easier the application. Further, as the viscosity of the material is lower, the inclusion of bubbles can be suppressed, and a high quality film can be formed. Further, the lower the viscosity of the material is, the thinner and more uniformly applied it is, so that the thinner resin layer 101 can be formed.

Here, when a photosensitive material is used for the resin layer 101, a part of the resin layer 101 can be removed by photolithography. For example, heat treatment (also referred to as prebaking treatment) for removing the solvent is performed after applying the material, and then exposure is performed. Subsequently, an unnecessary portion can be removed by performing development processing.

More specifically, a method for forming the resin layer 101 having an opening will be described. First, a photosensitive material is applied to the light absorption layer 103a to form a thin film, and heat treatment (prebaking treatment) for removing a solvent or the like is performed. Then, the resin layer 101 having an opening can be formed by exposing the material to light using a photomask and performing development treatment.

Subsequently, a heat treatment (post-baking treatment) for polymerizing the applied material is performed to form the resin layer 101. It is preferable that the heating be performed at a temperature higher than the maximum temperature of a manufacturing process of the transistor 110 later. For example, it is preferable to heat at 300 °C to 600 °C, preferably 350 °C to 550 °C, more preferably 400 °C to 500 °C, typically 450 °C. When the resin layer 101 is formed, the gas which can be released from the resin layer 101 can be removed by heating at such a temperature with the surface exposed, so that the gas is released during the manufacturing process of the transistor 110. Can be suppressed.

The thickness of the resin layer 101 is preferably 0.01 μm or more and less than 10 μm, more preferably 0.1 μm or more and 3 μm or less, and further preferably 0.5 μm or more and 1 μm or less. By using the low-viscosity solution, it becomes easy to form the resin layer 101 thinly and uniformly.

Further, the thermal expansion coefficient of the resin layer 101 is preferably 0.1 ppm/° C. or higher and 20 ppm/° C. or lower, and more preferably 0.1 ppm/° C. or higher and 10 ppm/° C. or lower. As the coefficient of thermal expansion of the resin layer 101 is lower, it is possible to suppress the damage of the transistor or the like due to the stress caused by the expansion or contraction due to heating.

When an oxide semiconductor film is used for the semiconductor layer 112 of the transistor 110, the resin layer 101 is not required to have high heat resistance because it can be formed at low temperature. The heat resistance of the resin layer 101 and the like can be evaluated by, for example, a weight reduction rate due to heating, specifically, a 5% weight reduction temperature. The 5% weight loss temperature of the resin layer 101 and the like can be 450% or less, preferably 400°C or less, more preferably less than 400°C, and further preferably less than 350°C. Further, it is preferable that the maximum temperature required for the formation process of the transistor 110 and the like be 350° C. or lower.

Here, the configuration is such that the opening is provided at a position where the resin layer 101 overlaps with the light emitting element 120, but the following configuration can be realized by using the above method. For example, by disposing the conductive layer so as to cover the opening, an electrode (also referred to as a back surface electrode or a through electrode) partially exposed on the back surface side can be formed after the peeling step described later. The electrode can also be used as an external connection terminal. Further, for example, the alignment accuracy can be improved by not providing the resin layer 101 in the marker portion for bonding the two display panels.

[Formation of insulating layer 131]
Then, the insulating layer 131 is formed over the resin layer 101 (FIG. 2C).

The insulating layer 131 can be used as a barrier layer that prevents impurities contained in the resin layer 101 from diffusing into a transistor or a light-emitting element which is formed later. Therefore, it is preferable to use a material having a high barrier property.

As the insulating layer 131, for example, an inorganic insulating material such as a silicon nitride film, a silicon oxynitride film, a silicon oxide film, a silicon nitride oxide film, an aluminum oxide film, or an aluminum nitride film can be used. Further, the above-mentioned two or more insulating films may be laminated and used. In particular, it is preferable to use a laminated film of a silicon nitride film and a silicon oxide film from the resin layer 101 side.

Further, when the surface of the resin layer 101 has unevenness, the insulating layer 131 preferably covers the unevenness. Further, the insulating layer 131 may have a function as a flattening layer which flattens the unevenness. For example, the insulating layer 131 is preferably formed by stacking an organic insulating material and an inorganic insulating material. Organic insulating materials include organic resins such as epoxy resin, acrylic resin, silicone resin, phenol resin, polyimide resin, imide resin, PVC (polyvinyl chloride) resin, PVB (polyvinyl butyral) resin and EVA (ethylene vinyl acetate) resin. Can be used.

The insulating layer 131 is preferably formed at a temperature of room temperature to 400° C. inclusive, preferably 100° C. to 350° C. inclusive, more preferably 150° C. to 300° C. inclusive.

[Formation of transistor]
Then, as illustrated in FIG. 2D, the transistor 110 is formed over the insulating layer 131. Here, as an example of the transistor 110, an example of manufacturing a bottom-gate transistor is illustrated.

The conductive layer 111 is formed over the insulating layer 131. The conductive layer 111 can be formed by forming a conductive film, forming a resist mask, etching the conductive film, and then removing the resist mask.

Then, the insulating layer 132 is formed. For the insulating layer 132, an inorganic insulating film that can be used for the insulating layer 131 can be used.

Then, the semiconductor layer 112 is formed. The semiconductor layer 112 can be formed by forming a semiconductor film, forming a resist mask, etching the semiconductor film, and then removing the resist mask.

The semiconductor film is formed at a substrate temperature of room temperature to 300 °C inclusive, preferably room temperature to 220 °C inclusive, more preferably room temperature to 200 °C inclusive, still more preferably room temperature to 170 °C inclusive. Here, that the substrate temperature at the time of film formation is room temperature means that the substrate is not intentionally heated. At this time, there is a case where the temperature becomes higher than room temperature due to the energy received by the substrate during film formation. Further, the room temperature refers to a temperature range of 10° C. or higher and 30° C. or lower, and is typically 25° C.

An oxide semiconductor is preferably used for the semiconductor film. In particular, it is preferable to apply an oxide semiconductor whose bandgap is larger than that of silicon. It is preferable to use a semiconductor material having a wider bandgap and a smaller carrier density than silicon because the current in the off state of the transistor can be reduced.

As the oxide semiconductor, a material having a bandgap of 2.5 eV or more, preferably 2.8 eV or more, more preferably 3.0 eV or more is preferably used. By using such an oxide semiconductor, in irradiation with light such as laser light in a separation step which will be described later, the light transmits through the semiconductor film, so that adverse effects on the electrical characteristics of the transistor are less likely to occur.

In particular, the semiconductor film used in one embodiment of the present invention can be formed by a sputtering method with the substrate being heated in an atmosphere containing one or both of an inert gas (eg, Ar) and an oxygen gas. preferable.

The substrate temperature during film formation is preferably room temperature or higher and 200° C. or lower, more preferably room temperature or higher and 170° C. or lower. By increasing the temperature of the substrate, more crystalline portions having orientation are formed, and a semiconductor film having excellent electrical stability can be formed. By using such a semiconductor film, a transistor having excellent electrical stability can be realized. Further, by forming the film with the substrate temperature lowered or without intentionally heating, a semiconductor film having a small proportion of crystal parts having orientation and high carrier mobility can be formed. By using such a semiconductor film, a transistor exhibiting high field-effect mobility can be realized.

Further, the flow rate ratio (oxygen partial pressure) of oxygen during film formation is 0% or more and less than 100%, preferably 0% or more and 50% or less, more preferably 0% or more and 33% or less, still more preferably 0% or more and 15% or more. % Or less is preferable. By reducing the oxygen flow rate, a semiconductor film having high carrier mobility can be formed and a transistor exhibiting higher field effect mobility can be realized.

By setting the substrate temperature during film formation and the oxygen flow rate during film formation within the above ranges, a semiconductor film in which crystal parts having orientation and crystal parts having no orientation are mixed can be obtained. .. Further, by optimizing the substrate temperature and the oxygen flow rate within the above-mentioned ranges, it becomes possible to control the existence ratio of the crystal part having orientation and the crystal part having no orientation.

The oxide target that can be used for forming the semiconductor film is not limited to the In—Ga—Zn-based oxide, and for example, an In—M—Zn-based oxide (M is Al, Y, or Sn). Can be applied.

In addition, when a semiconductor film including a crystal portion which is a semiconductor film is formed using a sputtering target including a polycrystalline oxide having a plurality of crystal grains, compared with a case where a sputtering target including no polycrystalline oxide is used. Therefore, a semiconductor film having crystallinity is easily obtained.

In particular, a crystal part having an orientation in the thickness direction of the film (also referred to as a film surface direction, a surface on which the film is formed, or a direction perpendicular to the surface of the film) and a crystal part which does not have such an orientation and are disordered A transistor to which a semiconductor film in which oriented crystal parts are mixed is applied has characteristics such that stability of electric characteristics can be increased and channel length can be easily reduced. On the other hand, a transistor to which a semiconductor film formed only of crystal parts having no orientation is applied can have high field-effect mobility. Note that as described later, by reducing oxygen vacancies in the oxide semiconductor, a transistor having both high field-effect mobility and high stability of electrical characteristics can be realized.

As described above, by using the oxide semiconductor film, heat treatment at high temperature or laser crystallization treatment which is required for LTPS is unnecessary, and the semiconductor layer 112 can be formed at an extremely low temperature. Therefore, the resin layer 101 can be thinly formed.

Then, the conductive layer 113a and the conductive layer 113b are formed. The conductive layers 113a and 113b can be formed by forming a conductive film, forming a resist mask, etching the conductive film, and then removing the resist mask.

Note that when the conductive layers 113a and 113b are processed, part of the semiconductor layer 112 which is not covered with the resist mask may be thinned by etching. It is preferable to use an oxide semiconductor film including a crystal part having orientation as the semiconductor layer 112 because this thinning can be suppressed.

As described above, the transistor 110 can be manufactured. The transistor 110 is a transistor including an oxide semiconductor in a semiconductor layer 112 in which a channel is formed. In the transistor 110, part of the conductive layer 111 functions as a gate, part of the insulating layer 132 functions as a gate insulating layer, and the conductive layers 113a and 113b each function as either a source or a drain. To do.

[Formation of insulating layer 133]
Then, an insulating layer 133 which covers the transistor 110 is formed. The insulating layer 133 can be formed by a method similar to that of the insulating layer 132.

The insulating layer 133 is preferably formed at a temperature of room temperature to 400° C. inclusive, preferably 100° C. to 350° C. inclusive, more preferably 150° C. to 300° C. inclusive. The higher the temperature, the denser the insulating film having a higher barrier property can be.

Further, as the insulating layer 133, it is preferable to use an oxide insulating film such as a silicon oxide film or a silicon oxynitride film formed at a low temperature as described above in an atmosphere containing oxygen. Further, it is preferable that an insulating film such as a silicon nitride film which is less likely to diffuse and transmit oxygen be stacked over the silicon oxide or silicon oxynitride film. The oxide insulating film formed at a low temperature in an atmosphere containing oxygen can be an insulating film from which a large amount of oxygen is easily released by heating. Oxygen can be supplied to the semiconductor layer 112 by performing heat treatment in a state where an oxide insulating film which emits oxygen and an insulating film which hardly diffuses and permeates oxygen are stacked. As a result, oxygen vacancies in the semiconductor layer 112 and defects at the interface between the semiconductor layer 112 and the insulating layer 133 can be repaired and the defect level can be reduced. As a result, a semiconductor device having extremely high reliability can be realized.

Through the above steps, the transistor 110 and the insulating layer 133 which covers the transistor 110 can be formed over the flexible resin layer 101. Note that at this stage, a flexible device having no display element can be manufactured by separating the resin layer 101 and the supporting substrate 61 by a method described later. For example, a flexible device having a semiconductor circuit can be manufactured by forming the transistor 110 or a capacitor, a resistor, a wiring, and the like in addition to the transistor 110.

[Formation of colored layer 152]
Then, the coloring layer 152 is formed over the insulating layer 132. The coloring layer 152 can be processed into an island shape by a photolithography method or the like by using a photosensitive material.

At this time, a light-blocking layer may be formed over the insulating layer 132. The light-blocking layer has a structure including an opening overlapping with the coloring layer 152 and the light-emitting element 120. The light-blocking layer may be provided so as to cover the transistor 110.

For the light shielding layer, for example, a metal material or a resin material can be used. When a metal material is used, it can be formed by removing an unnecessary portion by using a photolithography method or the like after forming a conductive film. When a photosensitive resin material containing a metal material, a pigment or a dye is used, it can be formed by a photolithography method or the like.

[Formation of insulating layer 134]
Then, the insulating layer 134 is formed over the insulating layer 133 and the coloring layer 152. The insulating layer 134 is a layer having a formation surface of a display element to be formed later, and thus is preferably a layer which functions as a planarization layer. As the insulating layer 134, an organic insulating film or an inorganic insulating film which can be used for the insulating layer 131 can be used.

As with the resin layer 101, the insulating layer 134 is preferably made of a photosensitive and thermosetting resin material. In particular, it is preferable to use the same material for the insulating layer 134 and the resin layer 101. As a result, the materials of the insulating layer 134 and the resin layer 101 and the devices for forming them can be made common.

The insulating layer 134 is preferably 0.01 μm or more and less than 10 μm, more preferably 0.1 μm or more and 3 μm or less, and further preferably 0.5 μm or more and 1 μm or less, like the resin layer 101. preferable. By using the low-viscosity solution, it becomes easy to form the insulating layer 134 thinly and uniformly.

[Formation of Light-Emitting Element 120]
Then, an opening reaching the conductive layer 113b and the like is formed in the insulating layer 134 and the insulating layer 133.

After that, the conductive layer 121 is formed. Part of the conductive layer 121 functions as a pixel electrode. The conductive layer 121 can be formed by forming a conductive film, forming a resist mask, etching the conductive film, and then removing the resist mask.

Subsequently, as illustrated in FIG. 2E, an insulating layer 135 which covers an end portion of the conductive layer 121 is formed. As the insulating layer 135, an organic insulating film or an inorganic insulating film which can be used for the insulating layer 131 can be used.

As with the resin layer 101, the insulating layer 135 is preferably made of a resin material having photosensitivity and thermosetting property. In particular, it is preferable to use the same material for the insulating layer 135 and the resin layer 101. This makes it possible to use the same material for the insulating layer 135 and the resin layer 101 and a device for forming them.

The insulating layer 135, like the resin layer 101, is preferably 0.01 μm or more and less than 10 μm, more preferably 0.1 μm or more and 3 μm or less, and further preferably 0.5 μm or more and 1 μm or less. preferable. By using a low-viscosity solution, it becomes easy to form the insulating layer 135 thinly and uniformly.

Then, the EL layer 122 and the conductive layer 123 are formed.

The EL layer 122 can be formed by a method such as an evaporation method, a coating method, a printing method, or a discharging method. When the EL layer 122 is formed for each pixel, it can be formed by an evaporation method using a shadow mask such as a metal mask, an inkjet method, or the like. When the EL layer 122 is not formed for each pixel, a vapor deposition method without using a metal mask can be used. Here, an example is shown in which it is formed by a vapor deposition method without using a metal mask.

The conductive layer 123 can be formed by an evaporation method, a sputtering method, or the like.

The light emitting element 120 can be formed as described above. The light-emitting element 120 has a structure in which a conductive layer 121, part of which functions as a pixel electrode, an EL layer 122, and a conductive layer 123, part of which functions as a common electrode are stacked.

[Formation of insulating layer 124]
Subsequently, as shown in FIG. 3A, an insulating layer 124 is formed so as to cover the conductive layer 123.

When an inorganic insulating film is used for the insulating layer 124, a film forming method such as a sputtering method, a plasma CVD method, an ALD method, or an evaporation method can be preferably used. Further, in order to prevent the light emitting element 120 from being damaged when the inorganic insulating film is formed, between the inorganic insulating film and the light emitting element 120, specifically, between the inorganic insulating film and the conductive layer 123, It is preferable to form an organic insulating film. At this time, the organic insulating film may be thin (for example, 100 nm or less), and can be formed using, for example, a vapor deposition method.

〔Lamination〕
Subsequently, as shown in FIG. 3B, the supporting substrate 61 and the substrate 11 are attached to each other with the adhesive layer 151. Then, the adhesive layer 151 is cured. Accordingly, the light emitting element 120 can be sealed with the adhesive layer 151.

The adhesive layer 151 is preferably made of a curable material. For example, a resin exhibiting photocurability, a resin exhibiting reaction cure property, a resin exhibiting thermosetting property, or the like can be used. In particular, it is preferable to use a resin material containing no solvent.

Through the above steps, the display panel 100 can be manufactured. At the time shown in FIG. 3B, the display panel 100 is in a state of being supported by the support substrate 61.

Subsequently, a method for manufacturing the display panel 200 will be described.

[Formation of Light Absorption Layer 103b]
The support substrate 63 is prepared, and the light absorption layer 103b is formed on the support substrate 63. The description of the support substrate 61 can be incorporated into the support substrate 63.

The light absorption layer 103b can be formed by using the same material and method as those of the light absorption layer 103a.

[Formation of Resin Layer 201]
Then, a resin layer 201 having an opening is formed on the light absorption layer 103b. Regarding the method and material for forming the resin layer 201, the same method as that for the resin layer 101 can be used.

[Formation of insulating layer 231]
Then, the insulating layer 231 is formed so as to cover the resin layer 201 and the opening portion of the resin layer 201 (FIG. 4A). The description of the insulating layer 131 can be referred to for the formation method and the material of the insulating layer 231.

[Formation of Transistor 210]
Subsequently, as illustrated in FIG. 4B, the transistor 210 is formed over the insulating layer 231.

The transistor 210 is formed by sequentially forming a conductive layer 211, an insulating layer 231, a semiconductor layer 212, a conductive layer 213a, and a conductive layer 213b. The description of the method for forming the transistor 110 can be applied to the method for forming each layer.

The transistor 210 is a transistor including an oxide semiconductor in a semiconductor layer 212 in which a channel is formed. In the transistor 210, part of the conductive layer 211 functions as a gate, part of the insulating layer 232 functions as a gate insulating layer, and the conductive layers 213a and 213b each function as either a source or a drain. To do.

[Formation of Conductive Layer 221 and Alignment Film 224a]
Then, an opening reaching the conductive layer 213b is formed in the insulating layer 234 and the insulating layer 233.

After that, the conductive layer 221 is formed. Part of the conductive layer 221 functions as a pixel electrode. The conductive layer 221 can be formed by forming a conductive film, forming a resist mask, etching the conductive film, and then removing the resist mask.

Subsequently, as shown in FIG. 4B, an alignment film 224a is formed over the conductive layer 221 and the insulating layer 234. The alignment film 224a can be formed by performing a rubbing process after forming a thin film of resin or the like.

Through the above steps, the transistor 210, the conductive layer 221, the alignment film 224a, and the like can be formed over the resin layer 201.

[Formation of Light Absorption Layer 103c]
The support substrate 64 is prepared, and the light absorption layer 103c is formed on the support substrate 64. The description of the support substrate 61 can be incorporated into the support substrate 64.

The light absorption layer 103c can be formed by using the same material and method as those of the light absorption layer 103a.

[Formation of resin layer 202]
Then, the resin layer 202 having an opening is formed on the light absorption layer 103b. Regarding the method and material for forming the resin layer 202, the same method as that for the resin layer 101 can be used.

[Formation of insulating layer 204]
Subsequently, the insulating layer 204 is formed so as to cover the resin layer 202 and the opening portion of the resin layer 202 (FIG. 4D). The description of the insulating layer 131 can be referred to for the formation method and the material of the insulating layer 204.

[Formation of Conductive Layer 223 and Alignment Film 224b]
Then, the conductive layer 223 is formed over the insulating layer 204. The conductive layer 223 can be formed by forming a conductive film. Note that the conductive layer 223 may be formed by a method such as a sputtering method using a shadow mask such as a metal mask so that the conductive layer 223 is not provided on the outer peripheral portion of the resin layer 202. Alternatively, after forming the conductive film, an unnecessary portion may be removed by etching by a photolithography method or the like.

Then, an alignment film 224b is formed over the conductive layer 223 (FIG. 4E). The alignment film 224b can be formed by a method similar to that of the alignment film 224a.

Through the above steps, the insulating layer 204, the conductive layer 223, and the alignment film 224b can be formed over the resin layer 202. Note that the manufacturing process on the resin layer 201 side and the manufacturing process on the resin layer 202 side can be performed independently of each other; therefore, the order is not limited. Alternatively, these two steps may be performed in parallel.

〔Lamination〕
Subsequently, as shown in FIG. 4F, the supporting substrate 63 and the supporting substrate 64 are attached to each other with the liquid crystal 222 interposed therebetween. At this time, the bonding is performed so that the opening of the resin layer 201 and the opening of the resin layer 202 overlap. At this time, the resin layer 201 and the resin layer 202 are adhered to each other on the outer peripheral portion by an adhesive layer (not shown).

For example, an adhesive layer (not shown) for adhering these to either or both of the resin layer 201 and the resin layer 202 is formed. The adhesive layer is formed so as to surround a region where pixels are arranged. The adhesive layer can be formed by, for example, a screen printing method or a dispensing method. As the adhesive layer, a thermosetting resin, an ultraviolet curable resin or the like can be used. Moreover, you may use the resin etc. which harden|cure by applying heat after temporarily hardening|curing with ultraviolet rays. Alternatively, as the adhesive layer, a resin having both ultraviolet curability and thermosetting property may be used.

Subsequently, the liquid crystal 222 is dropped on the region surrounded by the adhesive layer by a dispensing method or the like. Subsequently, the support substrate 63 and the support substrate 64 are attached so as to sandwich the liquid crystal 222, and the adhesive layer is cured. The bonding is preferably performed in a reduced pressure atmosphere because bubbles and the like can be prevented from entering between the supporting substrate 63 and the supporting substrate 64.

Note that after the liquid crystal 222 is dropped, granular gap spacers may be scattered over the region where pixels are arranged or outside the region, or the liquid crystal 222 including the gap spacer may be dropped. Alternatively, the liquid crystal 222 may be injected from the gap provided in the adhesive layer in a reduced pressure atmosphere after the supporting substrate 63 and the supporting substrate 64 are attached to each other.

Through the above steps, the display panel 200 can be manufactured. 4F, the display panel 100 is in a state of being sandwiched between the supporting substrate 61 and the supporting substrate 62.

[Separation of Support Substrate 62]
Then, as shown in FIG. 5A, the light absorption layer 103 a is irradiated with light 70 from the support substrate 61 side of the display panel 100 through the support substrate 61.

Laser light can be preferably used as the light 70. In particular, it is preferable to use a linear laser.

Note that a flash lamp or the like may be used as long as it can emit energy equivalent to that of laser light.

As the light 70, at least a part of the light is transmitted through the support substrate 61, and the light having a wavelength absorbed by the light absorption layer 103a is selected and used. Further, it is preferable to use the light having a wavelength absorbed by the resin layer 101 as the light 70. In particular, as the wavelength of the light 70, it is preferable to use light in the wavelength range of visible light to ultraviolet light. For example, it is preferable to use light having a wavelength of 200 nm or more and 400 nm or less, preferably light having a wavelength of 250 nm or more and 350 nm or more. In particular, it is preferable to use an excimer laser having a wavelength of 308 nm because it is excellent in productivity. Since the excimer laser is also used for laser crystallization in LTPS, the existing equipment of the LTPS production line can be used and new equipment investment is not required, which is preferable. Alternatively, a solid-state UV laser (also referred to as a semiconductor UV laser) such as a UV laser having a wavelength of 355 nm which is the third harmonic of an Nd:YAG laser may be used. Alternatively, a pulsed laser such as a picosecond laser may be used.

When a linear laser light is used as the light 70, the light 70 is scanned by moving the support substrate 61 and the light source relatively, and the light 70 is applied to the region to be peeled. At this stage, when the entire surface on which the resin layer 101 is arranged is irradiated, the entire resin layer 101 can be peeled off, and it is not necessary to divide the outer peripheral portion of the support substrate 61 by scribing or the like in a subsequent separation step. Alternatively, it is preferable to provide a region where the light 70 is not irradiated on the outer peripheral portion of the region where the resin layer 101 is arranged, because the resin layer 101 and the supporting substrate 61 can be prevented from being separated from each other when the light 70 is irradiated.

The irradiation of the light 70 heats the light absorption layer 103a, and hydrogen, oxygen, or the like is released from the light absorption layer 103a. The hydrogen or oxygen released at this time is released in the form of gas. The released gas remains in the vicinity of the interface between the light absorption layer 103a and the resin layer 101 or in the vicinity of the interface between the light absorption layer 103a and the support substrate 61, and a force for peeling them off is generated. As a result, the adhesiveness between the light absorption layer 103a and the resin layer 101 or the adhesiveness between the light absorption layer 103a and the support substrate 61 is reduced, and the state where the light absorption layer 103a and the support substrate 61 can be easily separated can be obtained.

In addition, part of the gas released from the light absorption layer 103a may remain in the light absorption layer 103a. Therefore, the light absorption layer 103a may become brittle and may be easily separated inside the light absorption layer 103a.

When a film that releases oxygen is used as the light absorption layer 103a, part of the resin layer 101 may be oxidized and embrittled by oxygen released from the light absorption layer 103a. Thus, the interface between the resin layer 101 and the light absorption layer 103a can be easily peeled off.

Also in the region overlapping with the opening of the resin layer 101, the adhesiveness at the interface between the light absorption layer 103a and the insulating layer 131 or the interface between the light absorption layer 103b and the support substrate 61 is reduced due to the same reason as described above. It becomes easy to peel off. Alternatively, the light absorption layer 103b may be fragile and easily separated.

On the other hand, the region where the light 70 is not irradiated has high adhesion.

Here, when an oxide semiconductor film is used for each of the light absorption layer 103a and the semiconductor layer 112, light having a wavelength that can be absorbed by the oxide semiconductor film is used as the light 70. However, below the transistor 110, the light absorption layer 103a and the resin layer 101 are laminated and arranged. Further, the resin layer 101 which has been subjected to sufficient heat treatment tends to absorb light more easily than the oxide semiconductor film, and can sufficiently absorb light even if it is thin. Therefore, even if some of the light 70 is transmitted by the light absorption layer 103a without being absorbed by the light absorption layer 103a, the light 70 is absorbed by the resin layer 101 and is prevented from reaching the semiconductor layer 112. As a result, the electric characteristics of the transistor 110 hardly change.

Then, the support substrate 61 and the resin layer 101 are separated (FIG. 5(B1)).

The separation can be performed by applying a pulling force to the supporting substrate 61 in the vertical direction with the substrate 11 fixed to the stage. For example, a part of the upper surface of the support substrate 61 may be adsorbed and pulled upward to be peeled off. The stage may have any configuration as long as it can fix the substrate 11, but may have a suction mechanism capable of vacuum suction, electrostatic suction, or the like, or have a mechanism for physically holding the substrate 11. May be. Alternatively, the supporting substrate 61 may be separated by applying a vertical pulling force to the substrate 11 with the supporting substrate 61 fixed to the stage.

Further, the separation may be performed by pressing a drum-shaped member having an adhesive property on the upper surface of the support substrate 61 or the substrate 11 and rotating the member. At this time, the stage may be moved in the peeling direction.

Further, when a region where the light 70 is not irradiated is provided in the outer peripheral portion of the resin layer 101, a notch may be formed in a part of the portion where the resin layer 101 is irradiated with the light, so as to trigger the peeling. The notch can be formed by using, for example, a sharp blade or a needle-shaped member, or cutting the support substrate 61 and the resin layer 101 simultaneously by scribing.

FIG. 5B1 illustrates an example in which peeling occurs at the interface between the light absorption layer 103a and the resin layer 101 and the interface between the light absorption layer 103a and the insulating layer 131.

In addition, FIG. 5B2 illustrates an example in which the light absorption layer 103aa which is part of the light absorption layer 103a remains in contact with the surfaces of the resin layer 101 and the insulating layer 131. For example, this corresponds to a case where separation (breakage) occurs inside the light absorption layer 103a. Note that when peeling occurs at the interface between the light absorption layer 103a and the supporting substrate 61, the entire light absorption layer 103a may remain in contact with the resin layer 101 and the insulating layer 131.

Thus, when the light absorption layer 103aa (or the light absorption layer 103a) remains, it is preferable to remove it. The light absorption layer 103aa can be removed by a dry etching method, a wet etching method, a sandblasting method, or the like, but the dry etching method is particularly preferable. Note that when the light absorption layer 103aa is removed, part of the resin layer 101 and part of the insulating layer 131 may be thinned by etching.

Note that when an insulating material having a light-transmitting property is used for the light-absorbing layer 103a or when the remaining light-absorbing layer 103aa is thin enough to have a light-transmitting property, the light-absorbing layer 103aa is left as it is. It may be in a state.

Although not shown here, it is preferable to fix the substrate 11 side to another support substrate in order to facilitate the transportation of the display panel 100 in the irradiation process of the light 70 and the separation process of the support substrate 61. For example, the substrate 11 and the supporting substrate can be fixed with an adhesive material, a double-sided tape, a silicone sheet, a water-soluble adhesive, or the like. In addition, it is preferable that the display panel 100 and the display panel 200, which will be described later, be easy because a step of attaching the display panel 100 and the display panel 200 can be facilitated by keeping the state of being fixed to the supporting substrate after the separation.

[Separation of Support Substrate 63]
Subsequently, as shown in FIG. 6A, the light absorption layer 103 b is irradiated with light 70 from the support substrate 63 side of the display panel 200 through the support substrate 62.

The above description can be applied to the irradiation method of the light 70.

Then, the support substrate 63 and the resin layer 201 are separated (FIG. 6B). The above description can be applied to the separation. FIG. 6B illustrates an example in which separation occurs at the interface between the light absorption layer 103b and the resin layer 201 and the interface between the light absorption layer 103b and the insulating layer 231.

[Lamination of display panel 100 and display panel 200]
Subsequently, as shown in FIG. 7A, the resin layer 101 of the display panel 100 and the resin layer 201 of the display panel 200 are attached to each other with the adhesive layer 50. As the adhesive layer 50, the description of the adhesive layer 151 can be applied.

It is important that the display panel 100 and the display panel 200 be attached so that the opening portion of the resin layer 101, the opening portion of the resin layer 201, the opening portion of the resin layer 202, and the light-emitting element 120 overlap with each other. ..

At this time, if the display panel 100 and the display panel 200 are displaced from each other, the light from the light emitting element 120 may be blocked by the light blocking member of the display panel 200. Further, the resin layer 201 or the resin layer 202 may be located on the optical path of the light from the light emitting element 120. Therefore, it is preferable that the display panel 100 and the display panel 200 be provided with markers for alignment, respectively.

[Separation of Support Substrate 64]
Subsequently, the light absorption layer 103c is irradiated with light 70 (not shown) from the support substrate 64 side through the support substrate 64. Then, as shown in FIG. 7B, the support substrate 64 and the resin layer 202 are separated. FIG. 7B illustrates an example in which peeling occurs at the interface between the light absorption layer 103c and the resin layer 202 and the interface between the light absorption layer 103c and the insulating layer 204.

The above description can be applied to the irradiation method of the light 70 (not shown).

The separation can be performed with the substrate 11 fixed to a stage or the like. The above description can be applied to the separation method.

[Lamination of substrate 12]
Then, the resin layer 202 and the substrate 12 are bonded together using the adhesive layer 52.

The description of the adhesive layer 151 can be applied to the adhesive layer 52.

Since the substrate 12 is a substrate located on the viewing side, a material having a property of transmitting visible light can be used.

Through the above steps, the display device 10 shown in FIG. 1 can be manufactured.

[Modification 1 of Example of Manufacturing Method]
Hereinafter, a method of forming a resin layer having an opening without using the light absorption layer will be described.

Although the resin layer 101 of the display panel 100 is described as an example here, the same method can be applied to the resin layer 201 and the resin layer 202 included in the display panel 200.

[Modification 1]
First, as shown in FIG. 8A, a resin layer 101 having a recess is formed.

First, a material to be the resin layer 101 is applied on the support substrate 61, and a pre-baking process is performed. Then, exposure is performed using a photomask. At this time, the recess amount can be formed in the resin layer 101 by reducing the exposure amount as compared with the condition of opening the resin layer 101. For example, a method of exposing for a shorter exposure time than the exposure condition for opening the resin layer 101, weakening the intensity of the exposure light, defocusing, forming the resin layer 101 thick, and the like can be mentioned.

Further, when it is desired to form both the opening and the recess in the resin layer 101, an exposure technique using a halftone mask or a graytone mask or a multiple exposure technique using two or more photomasks may be used.

After the exposure is performed as described above, the resin layer 101 having the recesses can be formed by performing the development process. After that, a post-baking process is performed.

Subsequently, as shown in FIG. 8B, an insulating layer 131 is formed so as to cover the upper surface and the concave portion of the resin layer 101.

FIG. 8C is a diagram in the step of irradiating the light 70 after the support substrate 61 and the substrate 11 are attached to each other.

As shown in FIG. 8C, the resin layer 101 is irradiated with light 70 from the support substrate 61 side through the support substrate 61. The above description can be applied to the irradiation method of the light 70. By irradiation with the light 70, the vicinity of the surface of the resin layer 101 on the side of the support substrate 61 or a part of the inside of the resin layer 101 is modified, and the adhesion between the support substrate 61 and the resin layer 101 is reduced.

Then, the support substrate 61 and the resin layer 101 are separated. The above can be applied to the method of separation.

Depending on the irradiation condition of the light 70, separation (breakage) may occur inside the resin layer 101, and a part of the resin layer 101 may remain on the support substrate 61 side. Alternatively, even when part of the surface of the resin layer 101 melts, part of the resin layer 101 may remain on the support substrate 61 side as well. Note that when peeling at the interface between the support substrate 61 and the resin layer 101, part of the resin layer 101 may not remain on the support substrate 61 side.

The thickness of the resin layer 101 remaining on the support substrate 61 side can be set to, for example, 100 nm or less, specifically, 40 nm or more and 70 nm or less. The supporting substrate 61 can be reused by removing the remaining resin layer 101. For example, when glass is used for the support substrate 61 and a polyimide resin is used for the resin layer 101, fuming nitric acid or the like can be used to remove the remaining resin layer 101.

FIG. 8D is a schematic cross-sectional view in a state after the support substrate 61 is peeled off.

After that, part of the surface of the resin layer 101 is etched so that part of the surface of the insulating layer 131 is exposed, so that the resin layer 101 having an opening is formed as illustrated in FIG. can do. For the etching, for example, plasma treatment (ashing treatment) in an atmosphere containing oxygen is preferable because controllability is improved and uniform etching can be performed.

Note that the resin layer 101 may not be etched and may remain in the state illustrated in FIG. Also in this configuration, since the resin layer 101 located on the path of the light from the light emitting element 120 is thinner than the other portions, absorption of light is suppressed and the light extraction efficiency can be improved.

[Modification 2]
In the following, a method different from that of Modification 1 will be described.

First, as illustrated in FIG. 9A, a resin layer 101b and a resin layer 101c having an opening are stacked over a supporting substrate 61.

The resin layer 101b can be formed using a method in which the exposure and development processes are omitted in the step of forming the resin layer 101. At this time, the pre-baking process is also unnecessary.

The resin layer 101c can be formed similarly to the resin layer 101.

Here, it is preferable that the resin layer 101b to be previously formed is sufficiently heat-treated and polymerized. Thereby, even when the same material is used for the resin layer 101b and the resin layer 101c, when the material to be the resin layer 101c to be formed later is applied, the resin layer 101b is dissolved in the solvent contained therein. Can be suppressed.

FIG. 9B is a diagram in the step of irradiating the light 70 after the support substrate 61 and the substrate 11 are bonded to each other. By irradiating with the light 70, the adhesiveness between the resin layer 101c and the supporting substrate 61 decreases.

FIG. 9C is a schematic cross-sectional view in a state after the support substrate 61 is peeled off.

After that, the resin layer 101b is etched so that the surface of the insulating layer 131 is exposed, whereby the resin layer 101 having an opening can be formed as illustrated in FIG. 9D. For the etching, for example, plasma treatment (ashing treatment) in an atmosphere containing oxygen is preferable because controllability is improved and uniform etching can be performed.

Note that when the same material is used for the resin layer 101b and the resin layer 101c, the material and the device can be made common, so that the productivity can be improved. Further, if different materials are used for these, the etching rate selection ratio can be increased, so that the degree of freedom in processing conditions can be expanded.

Note that the resin layer 101b may not be etched and may be left in the state illustrated in FIG. 9C. Also in this configuration, since the resin layer 101 (specifically, the resin layer 101b) located on the path of the light from the light emitting element 120 is thinner than the other portions, the light absorption is suppressed and the light extraction efficiency is reduced. Can be increased.

The above is the description of Modification 1 of the example of the manufacturing method.

[Modification 2 of Example of Manufacturing Method]
Hereinafter, a method of removing the resin layer after the peeling so that the resin layer does not remain on the optical path of the light emitting element 120 will be described.

First, as shown in FIG. 10A, the resin layer 101d is formed on the support substrate 61.

Like the resin layer 101b, the resin layer 101d can be formed by a method in which the exposure and development processes are omitted. After the formation of the resin layer 101d, heat treatment (post-baking treatment) is performed under the same conditions as for the resin layer 101.

FIG. 10B is a diagram in a step of irradiating with light 70 after the supporting substrate 61 and the substrate 11 are attached to each other. By irradiating with the light 70, the adhesiveness between the resin layer 101d and the support substrate 61 decreases.

FIG. 9C is a schematic sectional view in a state where the support substrate 61 is peeled off.

After that, the resin layer 101d is etched so that the insulating layer 131 is exposed, so that the resin layer 101d is removed as illustrated in FIG. The etching method for the resin layer 101b can be used for the etching.

As described above, by removing the resin layer 101d used for peeling from the support substrate 61 after the peeling, a structure in which the resin layer is not provided on the optical path of the light emitting element 120 can be obtained. At this time, as shown in FIG. 10D, since the upper surfaces of the insulating layer 131, the insulating layer 132, the insulating layer 133, and the like which are located on the formation surface side of the coloring layer 152 can be flattened, the thickness of the coloring layer 152 can be increased. It is possible to reduce the variation in the height.

The above is the description of Modification 2 of the example of the manufacturing method.

[Modification of Configuration Example]
In the following, a configuration example that is partially different from the configuration example illustrated in FIG. 1 will be described.

[Modification 1]
In FIG. 1, although the opening is provided in the resin layer located on the path of the light from the light emitting element 120, the opening is also provided in the resin layer located on the path of the light in the reflective liquid crystal element 220. It may be provided.

FIG. 11A shows an example having a region 32 in addition to the region 31. The region 32 is a region overlapping with the opening of the resin layer 202 and the liquid crystal element 220.

Note that FIG. 11A illustrates an example in which the resin layer 202 is provided with one opening portion that includes both the light-emitting element 120 and the liquid crystal element 220. The element 220 and the opening overlapping with the element 220 may be separately provided.

[Modification 2]
In FIG. 1 and the like, the insulating layer 124 functioning as a barrier layer is provided so as to cover the light-emitting element 120 and the substrate 11 is directly attached to the substrate with the adhesive layer 151; however, a barrier layer may be provided on the substrate 11 side. Good.

FIG. 11B shows a structure in which the insulating layer 141a, the resin layer 102, and the adhesive layer 51 are provided between the substrate 11 and the adhesive layer 151 from the light emitting element 120 side. One surface of the insulating layer 141a is attached by an adhesive layer 151, and the other surface is provided in contact with one surface of the resin layer 102. Further, the other surface of the resin layer 102 and the substrate 11 are bonded together by the adhesive layer 51.

The insulating layer 141a is a layer which functions as a barrier layer, and the same material as that of the insulating layer 141 can be used.

The resin layer 102 can have the same configuration as the resin layer 101 and the like.

A method for manufacturing the structure illustrated in FIG. 11B is described. The following method may be used instead of the step of bonding the substrates 11 (FIG. 3B) described in the manufacturing method of the display panel 100. First, the resin layer 102 and the insulating layer 141a are stacked and formed over a supporting substrate. Then, the insulating layer 141a and the supporting substrate 61 are attached to each other using the adhesive layer 151. After that, the resin layer 102 is irradiated with light 70 to separate between the support substrate and the resin layer 102. Further, the substrate 11 is attached to the separated surface of the resin layer 102 using the adhesive layer 51.

Note that the step of irradiating the resin layer 102 with light may be performed after the display panel 100 and the display panel 200 are attached to each other. The presence of the support substrate on the resin layer 102 side can facilitate the transportation.

[Modification 3]
In FIG. 1 and the like, the resin layer 202 is arranged on the display surface side of the display device 10 and the resin layer 202 and the substrate 12 are bonded together by the adhesive layer 52, but the resin layer 202 may not be arranged.

The structure illustrated in FIG. 12A includes a substrate 12a instead of the substrate 12, the adhesive layer 52, and the resin layer 202 illustrated in FIG. A conductive layer 223 and an alignment film 224b are stacked on the surface of the substrate 12a on the liquid crystal 222 side.

In addition, the structure illustrated in FIG. 12A includes a substrate 11a instead of the substrate 11. The substrate 11a is attached by the adhesive layer 151.

Here, for example, a substrate having poor flexibility may be used as either or both of the substrate 12a and the substrate 11a. At this time, a transparent substrate such as a glass substrate is used as the substrate 12a. A substrate that does not have a light-transmitting property such as a metal substrate may be used as the substrate 11a. By doing so, the substrate 12a and the substrate 11a can be used as supporting substrates, so that transportation during the manufacturing process can be facilitated. It is preferable to use a substrate having a thickness of 0.3 mm or more, preferably 0.5 mm or more as the substrate 12a or the substrate 11a because transportation becomes easy. Note that the substrate 12a and the substrate 11a may be bonded to each other and then the substrate 12a and the substrate 11a may be polished to reduce the thickness to less than 0.3 mm.

In addition, by using a substrate having poor flexibility for the substrate 12a and the substrate 11a, as compared with a case where flexible display panels are bonded to each other at the bonding stage of the display panel 100 and the display panel 200, It is possible to increase the accuracy of alignment and to achieve high definition of the display device. For example, it is possible to realize a display device having a definition higher than 500 ppi.

In addition, with such a structure, a step of forming the resin layer 202 on the display panel 200 side, a step of separating the resin layer 202 and the supporting substrate 64, a step of attaching the substrate 12, and the like can be omitted; The cost can be reduced.

[Modification 4]
As described in Modification 2 (FIG. 10) of the above manufacturing method example, a method of removing the resin layer by etching after the separation can be used. At this time, the resin layer does not remain in the completed display device 10.

FIG. 12B illustrates a structure which does not include the resin layer 101, the resin layer 201, and the resin layer 202 illustrated in FIG. 1 and the like. The insulating layer 204 is also omitted in FIG.

Here, for the formation of the conductive layer 223 and the alignment film 224b, a flexible film or the like is used for the substrate 12 for the reason that high temperature is not required and patterning with high accuracy is unnecessary. It is also possible to form the layer 223 and the alignment film 224b directly on the substrate 12.

With such a configuration, the display device 10 can be made extremely thin. At this time, a flexible display device can be realized by using a flexible substrate for the substrate 11 and the substrate 12.

[About transistor]
The display device 10 illustrated in FIG. 1 is an example in which a bottom-gate transistor is applied to both the transistor 110 and the transistor 210.

In the transistor 110, the conductive layer 111 functioning as a gate electrode is located closer to the formation surface side (the resin layer 101 side) than the semiconductor layer 112. Further, the insulating layer 132 is provided so as to cover the conductive layer 111. The semiconductor layer 112 is provided so as to cover the conductive layer 111. A region of the semiconductor layer 112 which overlaps with the conductive layer 111 corresponds to a channel formation region. In addition, the conductive layers 113a and 113b are provided in contact with the top surface and the side end portions of the semiconductor layer 112, respectively.

Note that the transistor 110 shows an example in which the width of the semiconductor layer 112 is larger than that of the conductive layer 111. With such a structure, the semiconductor layer 112 is provided between the conductive layer 111 and the conductive layer 113a or the conductive layer 113b, so that parasitic capacitance between the conductive layer 111 and the conductive layer 113a or the conductive layer 113b can be reduced. You can

The transistor 110 is a channel-etch type transistor and it is relatively easy to reduce the area occupied by the transistor, and thus can be preferably used for a high-definition display device.

The transistor 210 has the same characteristics as the transistor 110.

Here, a structural example of a transistor which can be applied to the transistor 110 and the transistor 210 is described.

A transistor 110a illustrated in FIG. 13A is different from the transistor 110 in that the transistor 110a includes a conductive layer 114 and an insulating layer 136. The conductive layer 114 is provided over the insulating layer 133 and has a region overlapping with the semiconductor layer 112. The insulating layer 136 is provided so as to cover the conductive layer 114 and the insulating layer 133.

The conductive layer 114 is located on the opposite side of the conductive layer 111 with the semiconductor layer 112 interposed therebetween. When the conductive layer 111 is the first gate electrode, the conductive layer 114 can function as the second gate electrode. By applying the same potential to the conductive layers 111 and 114, the on-state current of the transistor 110a can be increased. The threshold voltage of the transistor 110a can be controlled by applying a potential for controlling the threshold voltage to one of the conductive layers 111 and 114 and a driving potential to the other.

Here, it is preferable to use a conductive material containing an oxide for the conductive layer 114. Accordingly, when the conductive film forming the conductive layer 114 is formed in an atmosphere containing oxygen, oxygen can be supplied to the insulating layer 133. It is preferable that the proportion of oxygen gas in the film forming gas be in the range of 90% or more and 100% or less. The oxygen supplied to the insulating layer 133 is supplied to the semiconductor layer 112 by heat treatment performed later, so that oxygen vacancies in the semiconductor layer 112 can be reduced.

In particular, it is preferable to use a low resistance oxide semiconductor for the conductive layer 114. At this time, it is preferable to use an insulating film which releases hydrogen as the insulating layer 136, for example, a silicon nitride film. Hydrogen is supplied into the conductive layer 114 during the formation of the insulating layer 136 or by heat treatment thereafter, so that the electrical resistance of the conductive layer 114 can be effectively reduced.

A transistor 110b illustrated in FIG. 13B is a top-gate transistor.

In the transistor 110b, the conductive layer 111 which functions as a gate electrode is provided above the semiconductor layer 112 (on the side opposite to the formation surface side). Further, the semiconductor layer 112 is formed over the insulating layer 131. Further, the insulating layer 132 and the conductive layer 111 are stacked and formed over the semiconductor layer 112. The insulating layer 133 is provided so as to cover the top surface and the side end portion of the semiconductor layer 112, the side surface of the insulating layer 133, and the conductive layer 111. The conductive layers 113a and 113b are provided over the insulating layer 133. The conductive layers 113a and 113b are electrically connected to the top surface of the semiconductor layer 112 through the openings provided in the insulating layer 133.

Note that here, an example in which the insulating layer 132 is not present in a portion which does not overlap with the conductive layer 111 is shown; however, the insulating layer 132 may be provided so as to cover an upper surface and a side end portion of the semiconductor layer 112. ..

In the transistor 110b, a physical distance between the conductive layer 111 and the conductive layer 113a or the conductive layer 113b can be easily separated, so that parasitic capacitance between them can be reduced.

A transistor 110c illustrated in FIG. 13C is different from the transistor 110b in that it includes a conductive layer 115 and an insulating layer 137. The conductive layer 115 is provided over the insulating layer 131 and has a region overlapping with the semiconductor layer 112. The insulating layer 137 is provided so as to cover the conductive layer 115 and the insulating layer 131.

The conductive layer 115 functions as a second gate electrode similarly to the conductive layer 114. Therefore, it is possible to increase the on-current and control the threshold voltage.

A transistor 110a, a transistor 110b, a transistor 110c, or the like can be used instead of the transistor 110 illustrated in FIG. Further, instead of the transistor 210, the transistor 110a, the transistor 110b, the transistor 110c, or the like can be used.

Here, in the display device 10, the transistor included in the display panel 100 and the transistor included in the display panel 200 may be different transistors. As an example, a transistor electrically connected to the light-emitting element 120 needs to pass a relatively large current, and thus the transistor 110a or the transistor 110c is used, and the other transistors are provided in order to reduce the area occupied by the transistor. The transistor 110 can be applied.

As an example, FIG. 14 illustrates an example in which the transistor 110a is applied instead of the transistor 210 and the transistor 110c is applied instead of the transistor 110 in FIG.

The above is the description of the transistor.

At least part of this embodiment can be implemented in combination with any of the other embodiments described in this specification as appropriate.

(Embodiment 2)
In this embodiment, a more specific example of the display device of one embodiment of the present invention will be described. The display device illustrated below is a display device which has both a reflective liquid crystal element and a light emitting element and can perform display in both a transmissive mode and a reflective mode.

[Example of configuration]
FIG. 15A is a block diagram illustrating an example of the structure of the display device 400. The display device 400 includes a plurality of pixels 410 arranged in a matrix on the display portion 362. The display device 400 also includes a circuit GD and a circuit SD. In addition, the plurality of pixels 410 arranged in the direction R, the plurality of wirings G1, electrically connected to the circuit GD, the plurality of wirings G2, the plurality of wirings ANO, and the plurality of wirings CSCOM are provided. Further, the plurality of pixels 410 arranged in the direction C and the plurality of wirings S1 and the plurality of wirings S2 electrically connected to the circuit SD are included.

Note that the configuration including one circuit GD and one circuit SD is shown here for simplification, but the circuit GD and the circuit SD for driving the liquid crystal element and the circuit GD and the circuit SD for driving the light emitting element are separately provided. It may be provided in. More specifically, the display panel 100 and the display panel 200 illustrated in the first embodiment may individually include the circuit GD and the circuit SD.

The pixel 410 includes a reflective liquid crystal element and a light emitting element. In the pixel 410, the liquid crystal element and the light emitting element have portions overlapping with each other.

FIG. 15B1 illustrates a structural example of the electrode 311b included in the pixel 410. The electrode 311b functions as a reflective electrode of the liquid crystal element in the pixel 410. Further, the electrode 311b is provided with an opening 451.

In FIG. 15B1, the light-emitting element 360 located in a region overlapping with the electrode 311b is indicated by a dashed line. The light emitting element 360 is arranged so as to overlap with the opening 451 of the electrode 311b. Accordingly, the light emitted from the light emitting element 360 is emitted to the display surface side through the opening 451.

In FIG. 15B1, the pixels 410 adjacent to each other in the direction R are pixels corresponding to different colors. At this time, as shown in FIG. 15B1, in the two pixels adjacent to each other in the direction R, the openings 451 are preferably provided at different positions of the electrode 311b so as not to be arranged in a line. Accordingly, the two light-emitting elements 360 can be separated from each other and a phenomenon (also referred to as crosstalk) in which light emitted from the light-emitting elements 360 enters a coloring layer included in the adjacent pixel 410 can be suppressed. In addition, since two adjacent light emitting elements 360 can be arranged separately, a display device with high definition can be realized even when the EL layer of the light emitting element 360 is formed by a shadow mask or the like.

Alternatively, the arrangement may be as shown in FIG. 15B2.

If the value of the ratio of the total area of the openings 451 to the total area of the non-opening portions is too large, the display using the liquid crystal element becomes dark. Further, if the value of the ratio of the total area of the openings 451 to the total area of the non-opening portions is too small, the display using the light emitting element 360 becomes dark.

If the area of the opening 451 provided in the electrode 311b functioning as a reflective electrode is too small, the efficiency of light that can be extracted from the light emitted from the light-emitting element 360 is reduced.

The shape of the opening 451 can be, for example, a polygon, a quadrangle, an ellipse, a circle, a cross, or the like. Further, it may have an elongated strip shape, a slit shape, or a checkered shape. Further, the opening 451 may be arranged close to an adjacent pixel. Preferably, the opening 451 is arranged close to another pixel displaying the same color. Thereby, crosstalk can be suppressed.

[Circuit configuration example]
FIG. 16 is a circuit diagram showing a configuration example of the pixel 410. In FIG. 16, two adjacent pixels 410 are shown.

The pixel 410 includes a switch SW1, a capacitor C1, a liquid crystal element 340, a switch SW2, a transistor M, a capacitor C2, a light emitting element 360, and the like. The wiring G1, the wiring G2, the wiring ANO, the wiring CSCOM, the wiring S1, and the wiring S2 are electrically connected to the pixel 410. Further, in FIG. 16, a wiring VCOM1 electrically connected to the liquid crystal element 340 and a wiring VCOM2 electrically connected to the light emitting element 360 are shown.

FIG. 16 shows an example in which transistors are used for the switches SW1 and SW2.

In the switch SW1, a gate is connected to the wiring G1, one of a source and a drain is connected to the wiring S1, and the other of the source and the drain is connected to one electrode of the capacitor C1 and one electrode of the liquid crystal element 340. There is. The other electrode of the capacitor C1 is connected to the wiring CSCOM. The other electrode of the liquid crystal element 340 is connected to the wiring VCOM1.

The switch SW2 has a gate connected to the wiring G2, one of a source and a drain connected to the wiring S2, and the other of the source and the drain connected to one electrode of the capacitor C2 and the gate of the transistor M. The other electrode of the capacitor C2 is connected to one of the source and the drain of the transistor M and the wiring ANO. The other of the source and the drain of the transistor M is connected to one electrode of the light emitting element 360. The other electrode of the light emitting element 360 is connected to the wiring VCOM2.

FIG. 16 shows an example in which the transistor M has two gates sandwiching a semiconductor and these are connected. As a result, the current that the transistor M can flow can be increased.

A signal for controlling the switch SW1 to be in a conductive state or a non-conductive state can be given to the wiring G1. A predetermined potential can be applied to the wiring VCOM1. A signal for controlling the alignment state of liquid crystal included in the liquid crystal element 340 can be given to the wiring S1. A predetermined potential can be applied to the wiring CSCOM.

A signal for controlling the switch SW2 to be in a conductive state or a non-conductive state can be given to the wiring G2. The wiring VCOM2 and the wiring ANO can each be supplied with a potential which causes a potential difference in which the light-emitting element 360 emits light. A signal for controlling the conduction state of the transistor M can be given to the wiring S2.

When performing display in a reflective mode, for example, the pixel 410 illustrated in FIG. 16 can be driven by a signal applied to the wiring G1 and the wiring S1 and can be displayed by utilizing optical modulation by the liquid crystal element 340. In the case of performing display in the transmissive mode, the light emitting element 360 can be driven by a signal given to the wiring G2 and the wiring S2 to display. In the case of driving in both modes, the driving can be performed by signals given to the wiring G1, the wiring G2, the wiring S1, and the wiring S2.

Note that FIG. 16 illustrates an example in which one pixel 410 includes one liquid crystal element 340 and one light emitting element 360; however, the present invention is not limited to this. FIG. 17A illustrates an example in which one pixel 410 includes one liquid crystal element 340 and four light emitting elements 360 (light emitting elements 360r, 360g, 360b, 360w). The pixel 410 illustrated in FIG. 17A is different from that in FIG. 16 and is a pixel capable of full-color display with one pixel.

In FIG. 17A, in addition to the example in FIG. 16, a wiring G3 and a wiring S3 are connected to the pixel 410.

In the example illustrated in FIG. 17A, for example, the four light-emitting elements 360 can be light-emitting elements that emit red (R), green (G), blue (B), and white (W), respectively. Further, as the liquid crystal element 340, a reflective liquid crystal element exhibiting white can be used. As a result, when displaying in the reflection mode, it is possible to display white with high reflectance. Further, when the display is performed in the transmissive mode, display with high color rendering can be performed with low power.

In addition, FIG. 17B illustrates a structural example of the pixel 410. The pixel 410 includes a light emitting element 360w which overlaps with an opening portion of the electrode 311 and a light emitting element 360r, a light emitting element 360g, and a light emitting element 360b which are arranged around the electrode 311. The light emitting element 360r, the light emitting element 360g, and the light emitting element 360b preferably have substantially the same light emitting area.

[Example of display device configuration]
18 is a schematic perspective view of a display device 300 of one embodiment of the present invention. The display device 300 has a structure in which a substrate 351 and a substrate 361 are attached to each other. In FIG. 18, the substrate 361 is clearly indicated by a broken line.

The display device 300 includes a display portion 362, a circuit portion 364, a wiring 365, a circuit portion 366, a wiring 367, and the like. The substrate 351 is provided with, for example, a circuit portion 364, a wiring 365, a circuit portion 366, a wiring 367, an electrode 311b which functions as a pixel electrode, and the like. Further, FIG. 18 illustrates an example in which the IC 373, the FPC 372, the IC 375, and the FPC 374 are mounted on the substrate 351. Therefore, the structure illustrated in FIG. 18 can also be referred to as a display module including the display device 300, the IC 373, the FPC 372, the IC 375, and the FPC 374.

As the circuit portion 364, for example, a circuit which functions as a scan line driver circuit can be used.

The wiring 365 has a function of supplying a signal and power to the display portion and the circuit portion 364. The signal or power is input to the wiring 365 from the outside via the FPC 372 or from the IC 373.

Further, FIG. 18 illustrates an example in which the IC 373 is provided on the substrate 351 by a COG (Chip On Glass) method or the like. As the IC 373, for example, an IC having a function as a scan line driver circuit, a signal line driver circuit, or the like can be used. Note that when the display device 300 includes a circuit which functions as a scan line driver circuit and a signal line driver circuit, a circuit which functions as a scan line driver circuit or a signal line driver circuit is provided outside, and the display device 300 is driven through the FPC 372. The IC 373 may not be provided when a signal for inputting is input. Further, the IC 373 may be mounted on the FPC 372 by a COF (Chip On Film) method or the like.

FIG. 18 shows an enlarged view of a part of the display unit 362. In the display portion 362, electrodes 311b included in a plurality of display elements are arranged in matrix. The electrode 311b has a function of reflecting visible light and functions as a reflective electrode of a liquid crystal element 340 which will be described later.

Further, as shown in FIG. 18, the electrode 311b has an opening. Further, the light emitting element 360 is provided closer to the substrate 351 than the electrode 311b. The light from the light emitting element 360 is emitted to the substrate 361 side through the opening of the electrode 311b.

[Cross-section configuration example]
FIG. 19 illustrates a part of a region including the FPC 372, a part of a region including the circuit portion 364, a part of a region including the display portion 362, and a part of a region including the circuit portion 366 in the display device illustrated in FIG. , And an example of a cross section when a part of a region including the FPC 374 is cut.

The display device shown in FIG. 19 has a structure in which a display panel 100 and a display panel 200 are stacked. The display panel 100 has a resin layer 101 and a substrate 351. The display panel 200 has a resin layer 201 and a resin layer 202. The resin layer 101 and the resin layer 201 are adhered by the adhesive layer 50. The resin layer 202 is adhered to the substrate 361 by the adhesive layer 52.

[Display panel 100]

The display panel 100 includes a resin layer 101, an insulating layer 478, a plurality of transistors, a capacitor 405, a wiring 407, an insulating layer 411, an insulating layer 412, an insulating layer 413, an insulating layer 414, an insulating layer 415, a light emitting element 360, a spacer 416. The adhesive layer 417, the insulating layer 418, the coloring layer 425, and the like.

The resin layer 101 has an opening in a region overlapping with the light emitting element 360.

The circuit portion 364 includes the transistor 401. The display portion 362 includes a transistor 402, a transistor 403, and a capacitor 405.

Each transistor has a gate, an insulating layer 411, a semiconductor layer, a source, and a drain. The gate and the semiconductor layer overlap with each other with the insulating layer 411 provided therebetween. A part of the insulating layer 411 has a function as a gate insulating layer, and another part has a function as a dielectric of the capacitor 405. The conductive layer functioning as a source or a drain of the transistor 402 also serves as one electrode of the capacitor 405.

In FIG. 19, a bottom-gate transistor is shown. The circuit portion 364 and the display portion 362 may have different transistor structures. The circuit portion 364 and the display portion 362 may each include a plurality of types of transistors.

The capacitor 405 has a pair of electrodes and a dielectric substance therebetween. The capacitor 405 includes the same material as the gate of the transistor and the conductive layer formed in the same step, the same material as the source and drain of the transistor, and the conductive layer formed in the same step.

The insulating layer 412, the insulating layer 413, and the insulating layer 414 are provided so as to cover the transistor and the like, respectively. The number of insulating layers that cover the transistors and the like is not particularly limited. The insulating layer 414 has a function as a planarization layer. At least one layer of the insulating layer 412, the insulating layer 413, and the insulating layer 414 is preferably formed using a material in which impurities such as water or hydrogen are less likely to diffuse. It is possible to effectively prevent impurities from diffusing into the transistor from the outside, so that the reliability of the display device can be improved.

When an organic material is used for the insulating layer 414, impurities such as moisture may enter the light-emitting element 360 and the like from the outside of the display device through the insulating layer 414 exposed at the end portion of the display device. Deterioration of the light emitting element 360 due to intrusion of impurities leads to deterioration of the display device. Therefore, as shown in FIG. 19, the insulating layer 414 is preferably not located at the end portion of the display device. In the structure of FIG. 19, the insulating layer using an organic material is not located at the end portion of the display device, so that impurities can be prevented from entering the light-emitting element 360.

The light emitting element 360 includes an electrode 421, an EL layer 422, and an electrode 423. The light emitting element 360 may include the optical adjustment layer 424. The light emitting element 360 has a bottom emission structure that emits light to the electrode 421 side.

One of the electrode 421 and the electrode 423 functions as an anode, and the other functions as a cathode. When a voltage higher than the threshold voltage of the light emitting element 360 is applied between the electrode 421 and the electrode 423, holes are injected into the EL layer 422 from the anode side and electrons are injected from the cathode side. The injected electrons and holes are recombined in the EL layer 422, and the light emitting substance contained in the EL layer 422 emits light.

The electrode 421 is electrically connected to the source or the drain of the transistor 403. These may be directly connected or may be connected via another conductive layer. The electrode 421 functions as a pixel electrode and is provided for each light emitting element 360. The two adjacent electrodes 421 are electrically insulated by the insulating layer 415.

The EL layer 422 is a layer containing a light emitting substance.

The electrode 423 functions as a common electrode and is provided over the plurality of light-emitting elements 360. A constant potential is supplied to the electrode 423.

The light emitting element 360 is covered with the insulating layer 418. Further, an adhesive layer 417 which covers the insulating layer 418 and the like and adheres the substrate 351 is provided.

The light emitting element 360 overlaps with the coloring layer 425. The spacer 416 is provided in a portion which does not overlap with the light emitting element 360. Although FIG. 19 shows the case where there is a slight gap between the insulating layer 418 over the spacer 416 and the substrate 351, these may be in contact with each other. Although the spacer 416 is provided on the resin layer 101 side in FIG. 19, it may be provided on the substrate 351 side.

By combining the color filter (colored layer 425) and the microcavity structure (optical adjustment layer 424), light with high color purity can be extracted from the display device. The film thickness of the optical adjustment layer 424 is changed according to the color of each pixel.

The coloring layer 425 is a colored layer that transmits light in a specific wavelength band. For example, a color filter that transmits light in a red, green, blue, or yellow wavelength band can be used.

Note that one embodiment of the present invention is not limited to the color filter method, and a coloring method, a color conversion method, a quantum dot method, or the like may be applied.

Note that a light-blocking layer may be provided on the resin layer 101 side of the insulating layer 415. For example, it can be provided on the same formation surface as the coloring layer 425. The light blocking layer blocks light from the adjacent light emitting elements 360 and suppresses color mixing between the adjacent light emitting elements 360. Here, by providing the end portion of the coloring layer 425 so as to overlap with the light-blocking layer, light leakage can be suppressed. As the light blocking layer, a material that blocks the light emitted from the light emitting element 360 can be used. Note that it is preferable to provide the light-blocking layer in a region other than the display portion 362 such as the circuit portion 364 because unintended light leakage due to guided light or the like can be suppressed.

An insulating layer 478 is formed on one surface of the resin layer 101. An insulating layer 418 is formed so as to cover the light emitting element 360. It is preferable to use a highly moisture-proof film for the insulating layers 418 and 478. By disposing the light emitting element 360, the transistor, and the like between the pair of highly moisture-proof insulating layers, intrusion of impurities such as water into these elements can be suppressed and the reliability of the display device can be increased, which is preferable.

As the insulating film having high moisture resistance, a film containing nitrogen and silicon such as a silicon nitride film or a silicon nitride oxide film, a film containing nitrogen and aluminum such as an aluminum nitride film, or the like can be given. Alternatively, a silicon oxide film, a silicon oxynitride film, an aluminum oxide film, or the like may be used.

For example, the amount of water vapor permeation of an insulating film having high moisture resistance is 1×10 ⁻⁵ [g/(m ² ·day)] or less, preferably 1×10 ⁻⁶ [g/(m ² ·day)] or less, It is more preferably 1×10 ⁻⁷ [g/(m ² ·day)] or less, still more preferably 1×10 ⁻⁸ [g/(m ² ·day)] or less.

The connection portion 406 has a wiring 365. The wiring 365 can be formed using the same material and the same process as the source and drain of the transistor, for example. The connection portion 406 is electrically connected to an external input terminal that transmits a signal or a potential from the outside to the circuit portion 364. Here, an example in which the FPC 372 is provided as an external input terminal is shown. The FPC 372 and the connection portion 406 are electrically connected to each other through the connection layer 419.

As the connection layer 419, various anisotropic conductive films (ACF: Anisotropic Conductive Film), anisotropic conductive pastes (ACP: Anisotropic Conductive Paste), etc. can be used.

The above is the description of the display panel 100.

[Display panel 200]
The display panel 200 is a reflective liquid crystal display device to which a vertical electric field method is applied.

The display panel 200 includes a resin layer 201, an insulating layer 578, a plurality of transistors, a capacitor 505, a wiring 367, an insulating layer 511, an insulating layer 512, an insulating layer 513, an insulating layer 514, a liquid crystal element 340, an alignment film 564a, an alignment film. 564b, an adhesive layer 517, an insulating layer 576, and a resin layer 202.

The resin layer 201 and the resin layer 202 are attached to each other with an adhesive layer 517. Liquid crystal 563 is sealed in a region surrounded by the resin layer 201, the resin layer 202, and the adhesive layer 517. A polarizing plate 599 is located on the outer surface of the substrate 572.

Further, the resin layer 201 is provided with an opening overlapping with the light emitting element 360. Further, the resin layer 202 is provided with an opening overlapping with the liquid crystal element 340 and the light emitting element 360.

The liquid crystal element 340 includes an electrode 311b, an electrode 562, and a liquid crystal 563. The electrode 311b functions as a pixel electrode. The electrode 562 functions as a common electrode. The orientation of the liquid crystal 563 can be controlled by an electric field generated between the electrode 311b and the electrode 562. An alignment film 564a is provided between the liquid crystal 563 and the electrode 311b. An alignment film 564b is provided between the liquid crystal 563 and the electrode 562.

The resin layer 202 is provided with an insulating layer 576, an electrode 562, an alignment film 564b, and the like.

The resin layer 201 is provided with an electrode 311b, an alignment film 564a, a transistor 501, a transistor 503, a capacitor 505, a connecting portion 506, a wiring 367, and the like.

On the resin layer 201, insulating layers such as an insulating layer 511, an insulating layer 512, an insulating layer 513, and an insulating layer 514 are provided.

Here, of the source and the drain of the transistor 503, the conductive layer which is not electrically connected to the electrode 311b may function as part of the signal line. The conductive layer functioning as the gate of the transistor 503 may function as part of the scan line.

In FIG. 19, as an example of the display portion 362, a structure in which a coloring layer is not provided is shown. Therefore, the liquid crystal element 340 is an element that performs black and white gradation display.

FIG. 19 illustrates an example in which the transistor 501 is provided as an example of the circuit portion 366.

At least one of the insulating layer 512 and the insulating layer 513 which covers each transistor is preferably formed using a material in which impurities such as water and hydrogen are less likely to diffuse.

The electrode 311b is provided over the insulating layer 514. The electrode 311b is electrically connected to one of a source and a drain of the transistor 503 through an opening formed in the insulating layer 514, the insulating layer 513, the insulating layer 512, or the like. The electrode 311b is electrically connected to one electrode of the capacitor 505.

Since the display panel 200 is a reflective liquid crystal display device, a conductive material that reflects visible light is used for the electrode 311b and a conductive material that transmits visible light is used for the electrode 562.

As the conductive material that transmits visible light, for example, a material containing one kind selected from indium (In), zinc (Zn), and tin (Sn) may be used. Specifically, indium oxide, indium tin oxide (ITO), indium zinc oxide, indium oxide containing tungsten oxide, indium zinc oxide containing tungsten oxide, indium oxide containing titanium oxide, Indium tin oxide containing titanium oxide, indium tin oxide containing silicon oxide (ITSO), zinc oxide, zinc oxide containing gallium, and the like can be given. Note that a film containing graphene can also be used. The film containing graphene can be formed by reducing a film containing graphene oxide, which is formed into a film shape, for example.

Examples of the conductive material that reflects visible light include aluminum, silver, and alloys containing these metal materials. In addition, a metal material such as gold, platinum, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, or palladium, or an alloy containing these metal materials can be used. Further, lanthanum, neodymium, germanium, or the like may be added to the above metal material or alloy. Alloys of aluminum and titanium, alloys of aluminum and nickel, alloys of aluminum and neodymium, alloys containing aluminum such as aluminum, nickel, and lanthanum alloys (Al-Ni-La) (aluminum alloys), alloys of silver and copper, An alloy containing silver such as an alloy of silver, palladium, and copper (also referred to as Ag—Pd—Cu or APC) or an alloy of silver and magnesium may be used.

Here, a linear polarizing plate may be used as the polarizing plate 599, but a circular polarizing plate can also be used. As the circularly polarizing plate, for example, a layered product of a linearly polarizing plate and a quarter wave retardation plate can be used. Thereby, reflection of external light can be suppressed. In addition, a desired contrast may be realized by adjusting the cell gap, orientation, driving voltage, and the like of the liquid crystal element used for the liquid crystal element 340 in accordance with the kind of the polarizing plate 599.

The electrode 562 is electrically connected to a conductive layer provided on the resin layer 201 side by a connector 543 in a portion near the end of the resin layer 202. Accordingly, a potential or a signal can be supplied to the electrode 562 from the FPC 374, the IC, or the like arranged on the resin layer 201 side.

As the connection body 543, for example, conductive particles can be used. As the conductive particles, particles of organic resin or silica whose surface is coated with a metal material can be used. It is preferable to use nickel or gold as the metal material because the contact resistance can be reduced. Further, it is preferable to use particles obtained by coating two or more kinds of metal materials in layers, such as nickel being further coated with gold. Further, it is preferable to use a material that is elastically or plastically deformed as the connecting body 543. At this time, the connector 543, which is a conductive particle, may have a vertically crushed shape as shown in FIG. Thus, the contact area between the connection body 543 and the conductive layer electrically connected to the connection body 543 can be increased, contact resistance can be reduced, and defects such as connection failure can be suppressed.

The connection body 543 is preferably arranged so as to be covered with the adhesive layer 517. For example, the connection body 543 may be placed after applying a paste or the like to be the adhesive layer 517.

A connection portion 506 is provided in a region near the end of the resin layer 201. The connection portion 506 is electrically connected to the FPC 374 via the connection layer 519. The structure illustrated in FIG. 19 illustrates an example in which the connection portion 506 is formed by stacking part of the wiring 367 and a conductive layer obtained by processing the same conductive film as the electrode 311b.

The above is the description of the display panel 200.

[About each component]
Below, each component shown above is demonstrated.

〔substrate〕
A material having a flat surface can be used for the substrate included in the display panel. A material that transmits the light is used for the substrate on the side where the light from the display element is extracted. For example, materials such as glass, quartz, ceramics, sapphire, and organic resin can be used.

By using a thin substrate, the display panel can be lightweight and thin. Further, a flexible display panel can be realized by using a substrate having a thickness that is flexible.

Further, since the substrate from which light is not emitted does not have to have a light-transmitting property, a metal substrate or the like can be used in addition to the above substrates. Since the metal substrate has high thermal conductivity and can easily conduct heat to the entire substrate, a local temperature rise of the display panel can be suppressed, which is preferable. In order to obtain flexibility and bendability, the thickness of the metal substrate is preferably 10 μm or more and 400 μm or less, and more preferably 20 μm or more and 50 μm or less.

The material forming the metal substrate is not particularly limited, but for example, a metal such as aluminum, copper, or nickel, an aluminum alloy, an alloy such as stainless steel, or the like can be preferably used.

Alternatively, a substrate that has been subjected to an insulation treatment by oxidizing the surface of the metal substrate or forming an insulating film on the surface may be used. For example, the insulating film may be formed by using a coating method such as a spin coating method or a dipping method, an electrodeposition method, a vapor deposition method, or a sputtering method. Alternatively, the insulating film may be left standing in an oxygen atmosphere or heated, or an anodizing method may be used. For example, an oxide film may be formed on the surface of the substrate.

Examples of the material having flexibility and transparency to visible light include glass having a thickness of flexibility, polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), and polyacrylonitrile resin. , Polyimide resin, polymethylmethacrylate resin, polycarbonate (PC) resin, polyethersulfone (PES) resin, polyamide resin, cycloolefin resin, polystyrene resin, polyamideimide resin, polyvinyl chloride resin, polytetrafluoroethylene (PTFE) resin Etc. In particular, it is preferable to use a material having a low coefficient of thermal expansion, and for example, a polyamide-imide resin, a polyimide resin, PET or the like having a coefficient of thermal expansion of 30×10 ⁻⁶ /K or less can be preferably used. It is also possible to use a substrate in which glass fibers are impregnated with an organic resin or a substrate in which an inorganic filler is mixed with an organic resin to reduce the coefficient of thermal expansion. Since a substrate using such a material has a low weight, a display panel using the substrate can also be lightweight.

When the above-mentioned material contains a fibrous body, a high-strength fiber of an organic compound or an inorganic compound is used as the fibrous body. The high-strength fiber specifically refers to a fiber having a high tensile modulus or Young's modulus, and as a typical example, polyvinyl alcohol fiber, polyester fiber, polyamide fiber, polyethylene fiber, aramid fiber, Examples include polyparaphenylene benzobisoxazole fiber, glass fiber, or carbon fiber. Examples of the glass fibers include glass fibers using E glass, S glass, D glass, Q glass and the like. These may be used in a woven or non-woven state, and a structure obtained by impregnating this fibrous body with a resin and curing the resin may be used as a flexible substrate. It is preferable to use a structure formed of a fibrous body and a resin as the flexible substrate because reliability of damage to bending or local pressure is improved.

Alternatively, glass or metal that is thin enough to have flexibility can be used for the substrate. Alternatively, a composite material in which glass and a resin material are attached to each other with an adhesive layer may be used.

A flexible substrate is provided with a hard coat layer (for example, silicon nitride, aluminum oxide, etc.) that protects the surface of the display panel from scratches, a layer of a material that can disperse pressure (for example, aramid resin, etc.), etc. It may be laminated. In addition, an insulating film having low water permeability may be stacked over a flexible substrate in order to suppress reduction in life of the display element due to moisture or the like. For example, an inorganic insulating material such as silicon nitride, silicon oxynitride, silicon nitride oxide, aluminum oxide, or aluminum nitride can be used.

The substrate can also be used by stacking a plurality of layers. In particular, with the structure having the glass layer, the barrier property against water and oxygen can be improved and a highly reliable display panel can be obtained.

[Transistor]
The transistor includes a conductive layer functioning as a gate electrode, a semiconductor layer, a conductive layer functioning as a source electrode, a conductive layer functioning as a drain electrode, and an insulating layer functioning as a gate insulating layer. The above shows the case where a bottom-gate transistor is applied.

Note that there is no particular limitation on the structure of the transistor included in the display device of one embodiment of the present invention. For example, a planar transistor, a staggered transistor, or an inverted staggered transistor may be used. Further, either a top-gate or bottom-gate transistor structure may be used. Alternatively, gate electrodes may be provided above and below the channel.

There is no particular limitation on the crystallinity of a semiconductor material used for a transistor, either an amorphous semiconductor or a crystalline semiconductor (a microcrystalline semiconductor, a polycrystalline semiconductor, a single crystal semiconductor, or a semiconductor partially having a crystalline region). May be used. It is preferable to use a semiconductor having crystallinity because deterioration of transistor characteristics can be suppressed.

An oxide semiconductor can be used as a semiconductor material used for the transistor. Typically, an oxide semiconductor containing indium or the like can be used.

In particular, it is preferable to use a semiconductor material having a wider bandgap and a smaller carrier density than silicon because the current in the off state of the transistor can be reduced.

In addition, a transistor including an oxide semiconductor whose bandgap is larger than that of silicon can hold the charge accumulated in a capacitor connected in series with the transistor for a long period of time due to the low off-state current. .. By applying such a transistor to a pixel, the driving circuit can be stopped while maintaining the gradation of each pixel. As a result, a display device with extremely low power consumption can be realized.

The semiconductor layer is represented by an In-M-Zn-based oxide containing at least indium, zinc and M (a metal such as aluminum, titanium, gallium, germanium, yttrium, zirconium, lanthanum, cerium, tin, neodymium or hafnium). It is preferable to include a membrane. In addition, in order to reduce variations in electric characteristics of a transistor including the oxide semiconductor, it is preferable to include a stabilizer together with the oxide semiconductor.

Examples of the stabilizer include the lanthanoids praseodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, and lutetium, in addition to the metals described in M above.

Examples of oxide semiconductors included in the semiconductor layer include In-Ga-Zn-based oxides, In-Al-Zn-based oxides, In-Sn-Zn-based oxides, In-Hf-Zn-based oxides, In-. La-Zn-based oxide, In-Ce-Zn-based oxide, In-Pr-Zn-based oxide, In-Nd-Zn-based oxide, In-Sm-Zn-based oxide, In-Eu-Zn-based oxide. Products, In-Gd-Zn-based oxides, In-Tb-Zn-based oxides, In-Dy-Zn-based oxides, In-Ho-Zn-based oxides, In-Er-Zn-based oxides, In-Tm. -Zn-based oxide, In-Yb-Zn-based oxide, In-Lu-Zn-based oxide, In-Sn-Ga-Zn-based oxide, In-Hf-Ga-Zn-based oxide, In-Al- Ga-Zn-based oxide, In-Sn-Al-Zn-based oxide, In-Sn-Hf-Zn-based oxide, and In-Hf-Al-Zn-based oxide can be used.

Note that here, an In—Ga—Zn-based oxide means an oxide containing In, Ga, and Zn as main components, and the ratio of In, Ga, and Zn does not matter. Further, a metal element other than In, Ga and Zn may be contained.

Further, the semiconductor layer and the conductive layer may have the same metal element among the above oxides. The manufacturing cost can be reduced by using the same metal element for the semiconductor layer and the conductive layer. For example, the manufacturing cost can be reduced by using the metal oxide target having the same metal composition. Further, an etching gas or an etching solution for processing the semiconductor layer and the conductive layer can be commonly used. However, the semiconductor layer and the conductive layer may have different compositions even if they have the same metal element. For example, a metal element in a film may be released during a manufacturing process of a transistor and a capacitor to have a different metal composition.

It is preferable that the oxide semiconductor forming the semiconductor layer has an energy gap of 2 eV or more, preferably 2.5 eV or more, more preferably 3 eV or more. By using an oxide semiconductor having a wide energy gap in this manner, off-state current of the transistor can be reduced.

When the oxide semiconductor included in the semiconductor layer is an In-M-Zn-based oxide, the atomic ratio of the metal elements in the sputtering target used for forming the In-M-Zn oxide is In?M, Zn. It is preferable to satisfy ≧M. As the atomic ratio of the metal elements of such a sputtering target, In:M:Zn=1:1:1, In:M:Zn=1:1:1.2, In:M:Zn=3:1:. 2, In:M:Zn=4:2:3, In:M:Zn=4:2:4.1, In:M:Zn=5:1:6, In:M:Zn=5:1: 7, In:M:Zn=5:1:8 and the like are preferable. Note that the atomic ratio of the semiconductor layers to be formed includes a fluctuation of ±40% in the atomic ratio of the metal elements contained in the sputtering target.

The bottom-gate transistor illustrated in this embodiment is preferable because the number of manufacturing steps can be reduced. Further, at this time, by using an oxide semiconductor, it can be formed at a temperature lower than that of polycrystalline silicon. Since the wiring below the semiconductor layer can be formed of an electrode material and a substrate, a low heat resistance material can be used. , The range of choice of materials can be expanded. For example, a glass substrate having an extremely large area can be preferably used.

(Conductive layer)
Materials that can be used for conductive layers such as gates, sources, and drains of transistors as well as various wirings and electrodes included in a display device include aluminum, titanium, chromium, nickel, copper, yttrium, zirconium, molybdenum, silver, and A metal such as tantalum or tungsten, or an alloy containing this as a main component can be given. Further, a film containing these materials can be used as a single layer or as a laminated structure. For example, a single-layer structure of an aluminum film containing silicon, a two-layer structure of laminating an aluminum film on a titanium film, a two-layer structure of laminating an aluminum film on a tungsten film, and a copper film on a copper-magnesium-aluminum alloy film. Two-layer structure of stacking, two-layer structure of stacking a copper film on a titanium film, two-layer structure of stacking a copper film on a tungsten film, a titanium film or a titanium nitride film, and an aluminum film or a copper film stacked thereon A three-layer structure in which a titanium film or a titanium nitride film is further stacked, a molybdenum film or a molybdenum nitride film, and an aluminum film or a copper film are stacked thereover, and further a molybdenum film or There is a three-layer structure in which a molybdenum nitride film is formed. Note that an oxide such as indium oxide, tin oxide, or zinc oxide may be used. Further, it is preferable to use copper containing manganese because controllability of a shape by etching is improved.

As the light-transmitting conductive material, a conductive oxide such as indium oxide, indium tin oxide, indium zinc oxide, zinc oxide, or zinc oxide to which gallium is added, or graphene can be used. Alternatively, a metal material such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, or titanium, or an alloy material containing the metal material can be used. Alternatively, a nitride of the metal material (for example, titanium nitride) or the like may be used. Note that when a metal material or an alloy material (or a nitride thereof) is used, it may be thin enough to have a light-transmitting property. Alternatively, a stacked film of any of the above materials can be used as the conductive layer. For example, it is preferable to use a stacked film of an alloy of silver and magnesium and indium tin oxide because conductivity can be increased. These can also be used for conductive layers such as various wirings and electrodes that form a display device, or for a conductive layer included in a display element (a conductive layer functioning as a pixel electrode or a common electrode).

[Insulation layer]
As the insulating material that can be used for each insulating layer, for example, an inorganic insulating material such as silicon oxide, silicon oxynitride, silicon nitride oxide, silicon nitride, or aluminum oxide is used in addition to polyimide, acrylic, epoxy, or silicone resin. You can also

Further, the light emitting element is preferably provided between a pair of insulating films having low water permeability. As a result, impurities such as water can be prevented from entering the light emitting element, and reduction in reliability of the device can be suppressed.

As the insulating film having low water permeability, a film containing nitrogen and silicon such as a silicon nitride film or a silicon nitride oxide film, a film containing nitrogen and aluminum such as an aluminum nitride film, or the like can be given. Alternatively, a silicon oxide film, a silicon oxynitride film, an aluminum oxide film, or the like may be used.

For example, the amount of water vapor permeation through an insulating film having low water permeability is 1×10 ⁻⁵ [g/(m ² ·day)] or less, preferably 1×10 ⁻⁶ [g/(m ² ·day)] or less, It is more preferably 1×10 ⁻⁷ [g/(m ² ·day)] or less, still more preferably 1×10 ⁻⁸ [g/(m ² ·day)] or less.

[About display element]
As a display element included in the first pixel located on the display surface side, an element that reflects external light and performs display can be used. Since such an element does not have a light source, power consumption during display can be extremely reduced. A reflective liquid crystal element can be typically used for the display element included in the first pixel. Alternatively, as a display element included in the first pixel, in addition to a shutter-type Micro Electro Mechanical System (MEMS) element, a MEMS element of an optical interference method, a microcapsule method, an electrophoresis method, an electrowetting method, an electronic powder fluid ( An element or the like to which the registered trademark) method or the like is applied can be used.

Further, the display element included in the second pixel located on the side opposite to the display surface side has a light source, and an element for displaying using light from the light source can be used. The brightness and chromaticity of the light emitted from such a pixel is not influenced by external light, and thus the color reproducibility is high (the color gamut is wide) and the contrast is high, that is, vivid display is performed. be able to. As the display element included in the second pixel, a self-luminous light emitting element such as an OLED (Organic Light Emitting Diode), an LED (Light Emitting Diode), or a QLED (Quantum-dot Light Emitting Diode) can be used. Alternatively, as the display element included in the second pixel, a combination of a backlight which is a light source and a transmissive liquid crystal element which controls the amount of light transmitted from the backlight may be used.

[Liquid crystal element]
As the liquid crystal element, for example, a liquid crystal element to which a vertical alignment (VA: Vertical Alignment) mode is applied can be used. As the vertical alignment mode, MVA (Multi-Domain Vertical Alignment) mode, PVA (Patterned Vertical Alignment) mode, ASV (Advanced Super View) mode and the like can be used.

Liquid crystal elements to which various modes are applied can be used as the liquid crystal element. For example, in addition to the VA mode, a TN (Twisted Nematic) mode, an IPS (In-Plane-Switching) mode, an FFS (Fringe Field Switching) mode, an ASM (Axially Synthesized Aligned Micro-cell Aligned Micro-cell) Bidirectional (OC) mode, and an OC (Occupied) mode. , A liquid crystal element to which an FLC (Ferroelectric Liquid Crystal) mode, an AFLC (Antiferroelectric Liquid Crystal) mode, or the like is applied can be used.

The liquid crystal element is an element that controls transmission or non-transmission of light by an optical modulation action of liquid crystal. Note that the optical modulation action of the liquid crystal is controlled by an electric field applied to the liquid crystal (including a horizontal electric field, a vertical electric field, or an oblique electric field). As the liquid crystal used for the liquid crystal element, thermotropic liquid crystal, low molecular weight liquid crystal, polymer liquid crystal, polymer dispersed liquid crystal (PDLC: Polymer Dispersed Liquid Crystal), ferroelectric liquid crystal, antiferroelectric liquid crystal, or the like may be used. You can These liquid crystal materials show a cholesteric phase, a smectic phase, a cubic phase, a chiral nematic phase, an isotropic phase, etc. depending on the conditions.

Further, as the liquid crystal material, either a positive type liquid crystal or a negative type liquid crystal may be used, and an optimal liquid crystal material may be used depending on the mode and design to be applied.

Further, an alignment film can be provided to control the alignment of the liquid crystal. Note that when the horizontal electric field method is used, liquid crystal exhibiting a blue phase for which an alignment film is unnecessary may be used. The blue phase is one of the liquid crystal phases, and is a phase that appears immediately before the transition from the cholesteric phase to the isotropic phase when the temperature of the cholesteric liquid crystal is increased. Since the blue phase appears only in a narrow temperature range, a liquid crystal composition in which a chiral agent of several wt% or more is mixed is used for the liquid crystal layer in order to improve the temperature range. A liquid crystal composition containing a liquid crystal exhibiting a blue phase and a chiral agent has a short response speed and is optically isotropic. A liquid crystal composition containing a liquid crystal exhibiting a blue phase and a chiral agent does not require alignment treatment and has small viewing angle dependence. Further, since it is not necessary to provide an alignment film, rubbing treatment is unnecessary, and thus electrostatic breakdown caused by the rubbing treatment can be prevented and defects and damages of the liquid crystal display device during a manufacturing process can be reduced. ..

In one embodiment of the present invention, a reflective liquid crystal element can be used.

When a reflective liquid crystal element is used, a polarizing plate is provided on the display surface side. In addition to this, it is preferable to dispose a light diffusion plate on the display surface side because the visibility can be improved.

[Light emitting element]
As the light-emitting element, an element capable of self-luminance can be used, and an element whose luminance is controlled by current or voltage is included in its category. For example, an LED, a QLED, an organic EL element, an inorganic EL element or the like can be used.

In one embodiment of the present invention, it is particularly preferable to use a bottom emission type light emitting element as the light emitting element. A conductive film that transmits visible light is used for the electrode on the light extraction side. Further, it is preferable to use a conductive film that reflects visible light for the electrode from which light is not extracted.

The EL layer has at least a light emitting layer. As a layer other than the light-emitting layer, the EL layer is a substance having a high hole injecting property, a substance having a high hole transporting property, a hole blocking material, a substance having a high electron transporting property, a substance having a high electron injecting property, or a bipolar property. A layer containing a substance (a substance having a high electron-transporting property and a high hole-transporting property) or the like may be further included.

For the EL layer, either a low molecular weight compound or a high molecular weight compound may be used, and an inorganic compound may be contained. The layers forming the EL layer can be formed by methods such as a vapor deposition method (including a vacuum vapor deposition method), a transfer method, a printing method, an inkjet method, and a coating method.

When a voltage higher than the threshold voltage of the light emitting element is applied between the cathode and the anode, holes are injected into the EL layer from the anode side and electrons are injected from the cathode side. The injected electrons and holes are recombined in the EL layer, and the light emitting substance contained in the EL layer emits light.

When a white light emitting element is applied as the light emitting element, it is preferable that the EL layer contains two or more kinds of light emitting substances. For example, white light emission can be obtained by selecting the light-emitting substance so that the light emission of each of the two or more light-emitting substances has a complementary color relationship. For example, a luminescent substance that emits light such as R (red), G (green), B (blue), Y (yellow), and O (orange), or spectral components of two or more colors of R, G, and B. It is preferable that two or more of the light-emitting substances that emit light including are included. Further, it is preferable to apply a light-emitting element in which a spectrum of light emitted from the light-emitting element has two or more peaks within a wavelength range of a visible light region (e.g., 350 nm to 750 nm). Further, the emission spectrum of the material having a peak in the yellow wavelength region is preferably a material having spectral components also in the green and red wavelength regions.

The EL layer preferably has a structure in which a light-emitting layer containing a light-emitting material emitting one color and a light-emitting layer containing a light-emitting material emitting another color are stacked. For example, the plurality of light emitting layers in the EL layer may be stacked in contact with each other, or may be stacked via a region not containing any light emitting material. For example, as a structure in which a region containing the same material (for example, a host material or an assist material) as that of the fluorescent light emitting layer or the phosphorescent light emitting layer and not containing any light emitting material is provided between the fluorescent light emitting layer and the phosphorescent light emitting layer. Good. This facilitates the fabrication of the light emitting element and reduces the driving voltage.

Further, the light emitting element may be a single element having one EL layer, or may be a tandem element in which a plurality of EL layers are stacked with a charge generating layer interposed therebetween.

Note that the above-described light-emitting layer, and a layer containing a substance having a high hole-injection property, a substance having a high hole-transport property, a substance having a high electron-transport property, a substance having a high electron-injection property, a bipolar substance, or the like, Each may have an inorganic compound such as a quantum dot or a polymer compound (oligomer, dendrimer, polymer, etc.). For example, by using quantum dots in the light emitting layer, they can function as a light emitting material.

As the quantum dot material, colloidal quantum dot material, alloy type quantum dot material, core/shell type quantum dot material, core type quantum dot material and the like can be used. Alternatively, a material containing an element group of groups 12 and 16, groups 13 and 15, or groups 14 and 16 may be used. Alternatively, a quantum dot material containing an element such as cadmium, selenium, zinc, sulfur, phosphorus, indium, tellurium, lead, gallium, arsenic, or aluminum may be used.

The conductive film which transmits visible light can be formed using, for example, indium oxide, indium tin oxide, indium zinc oxide, zinc oxide, zinc oxide to which gallium is added, or the like. Further, metal materials such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, or titanium, alloys containing these metal materials, or nitrides of these metal materials (for example, Titanium nitride) or the like can also be used by forming it so thin that it has a light-transmitting property. Alternatively, a stacked film of any of the above materials can be used as the conductive layer. For example, it is preferable to use a stacked film of an alloy of silver and magnesium and indium tin oxide because conductivity can be increased. Alternatively, graphene or the like may be used.

For the conductive film that reflects visible light, for example, a metal material such as aluminum, gold, platinum, silver, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, or palladium, or an alloy containing these metal materials is used. You can Further, lanthanum, neodymium, germanium, or the like may be added to the above metal material or alloy. Alternatively, an alloy containing aluminum such as titanium, nickel, or neodymium (aluminum alloy) may be used. Alternatively, an alloy containing silver with copper, palladium, or magnesium may be used. An alloy containing silver and copper is preferable because it has high heat resistance. Further, by stacking the metal film or the metal oxide film in contact with the aluminum film or the aluminum alloy film, oxidation can be suppressed. Examples of materials for such metal films and metal oxide films include titanium and titanium oxide. Further, a conductive film that transmits visible light and a film made of a metal material may be stacked. For example, a laminated film of silver and indium tin oxide, a laminated film of an alloy of silver and magnesium and indium tin oxide, or the like can be used.

The electrodes may be formed by a vapor deposition method or a sputtering method, respectively. In addition, a discharge method such as an inkjet method, a printing method such as a screen printing method, or a plating method can be used.

[Adhesive layer]
As the adhesive layer, various curable adhesives such as photo-curable adhesives such as ultraviolet curable adhesives, reaction curable adhesives, thermosetting adhesives and anaerobic adhesives can be used. Examples of these adhesives include epoxy resin, acrylic resin, silicone resin, phenol resin, polyimide resin, imide resin, PVC (polyvinyl chloride) resin, PVB (polyvinyl butyral) resin, EVA (ethylene vinyl acetate) resin and the like. In particular, a material having low moisture permeability such as epoxy resin is preferable. Alternatively, a two-liquid mixed type resin may be used. Alternatively, an adhesive sheet or the like may be used.

Further, the resin may contain a desiccant. For example, a substance that adsorbs water by chemisorption, such as an alkaline earth metal oxide (such as calcium oxide or barium oxide), can be used. Alternatively, a substance that adsorbs water by physical adsorption, such as zeolite or silica gel, may be used. The inclusion of the desiccant is preferable because impurities such as moisture can be prevented from entering the element and the reliability of the display panel can be improved.

Further, the light extraction efficiency can be improved by mixing the resin with a filler having a high refractive index or a light scattering member. For example, titanium oxide, barium oxide, zeolite, zirconium or the like can be used.

[Connecting layer]
As the connection layer, an anisotropic conductive film (ACF: Anisotropic Conductive Film), an anisotropic conductive paste (ACP: Anisotropic Conductive Paste), or the like can be used.

[Colored layer]
Examples of the material that can be used for the colored layer include a metal material, a resin material, and a resin material containing a pigment or a dye.

[Shading layer]
Examples of materials that can be used as the light-shielding layer include carbon black, titanium black, metals, metal oxides, and complex oxides containing a solid solution of a plurality of metal oxides. The light shielding layer may be a film containing a resin material or a thin film of an inorganic material such as metal. Alternatively, a stacked film of films including a material for the coloring layer can be used for the light-blocking layer. For example, a stacked structure of a film containing a material used for a colored layer which transmits light of a certain color and a film containing a material used for a colored layer which transmits light of another color can be used. It is preferable to use the same material for the colored layer and the light-shielding layer because the device can be used in common and the process can be simplified.

The above is a description of each component.

[Modification]
In the following, an example in which a part of the configuration is different from that of the display device illustrated in the cross-sectional configuration example will be described. It should be noted that the description of the same parts as those described above will be omitted, and only the differences will be described.

[Modification 1 of Cross-sectional Configuration Example]
20 is different from that in FIG. 19 in that the structure of the transistor and the structure of the resin layer 202 are different, and that the coloring layer 565, the light-blocking layer 566, and the insulating layer 567 are provided.

The transistor 401, the transistor 403, and the transistor 501 illustrated in FIG. 20 each have a second gate electrode. Thus, it is preferable to apply a transistor having a pair of gates to a transistor provided in the circuit portion 364 or the circuit portion 366, a transistor for controlling a current flowing in the light-emitting element 360, or the like.

In the resin layer 202, an opening overlapping with the liquid crystal element 340 and an opening overlapping with the light emitting element 360 are provided separately. Thereby, the reflectance of the liquid crystal element 340 can be improved.

Further, a light-blocking layer 566 and a coloring layer 565 are provided on the surface of the insulating layer 576 on the liquid crystal element 340 side. The coloring layer 565 is provided so as to overlap with the liquid crystal element 340. As a result, the display panel 200 can perform color display. The light-blocking layer 566 has an opening overlapping with the liquid crystal element 340 and an opening overlapping with the light emitting element 360. As a result, color mixture between adjacent pixels can be suppressed, and a display device with high color reproducibility can be realized.

[Modification 2 of Cross-sectional Configuration Example]
21 differs from FIG. 19 in the configuration of the transistor and the configuration on the substrate 351 side.

FIG. 21 shows an example in which a top gate type transistor is applied to each transistor. As described above, by using a top-gate transistor, parasitic capacitance can be reduced, so that a display frame frequency can be increased. Further, it can be suitably used for a large-sized display panel of, for example, 8 inches or more.

In addition, FIG. 21 illustrates a structure in which the insulating layer 476, the resin layer 102, and the adhesive layer 51 are provided between the substrate 351 and the adhesive layer 417 from the light emitting element 360 side. One surface of the insulating layer 476 is attached by an adhesive layer 417 and the other surface is provided in contact with one surface of the resin layer 102. Further, the other surface of the resin layer 102 and the substrate 351 are attached to each other with the adhesive layer 51. Further, FIG. 21 shows an example in which the insulating layer 418 is not provided.

With such a structure, it is not necessary to directly cover the light emitting element 360 and form the insulating layer 418, so that the light emitting element 360 can be prevented from being damaged when the insulating layer 418 is formed.

[Modification 3 of Cross-sectional Configuration Example]
FIG. 22 shows an example in which a top gate type transistor having a second gate electrode is applied to each transistor.

Each transistor has a conductive layer 591 in contact with the resin layer 101 or the resin layer 201. An insulating layer 578 is provided so as to cover the conductive layer 591.

Further, in the connection portion 506 of the display panel 200, a part of the resin layer 201 is opened, and a conductive layer 592 is provided so as to fill the opening. The conductive layer 592 is provided so that the surface on the back surface side (display panel 100 side) is exposed. The conductive layer 592 is electrically connected to the wiring 367. The FPC 374 is electrically connected to the exposed surface of the conductive layer 592 through the connection layer 519. The conductive layer 592 can be formed by processing the same conductive film as the conductive layer 591. The conductive layer 592 functions as an electrode which can also be called a back surface electrode.

Such a structure can be realized by using a photosensitive organic resin for the resin layer 201. For example, when the resin layer 201 is formed over the supporting substrate, an opening is formed in the resin layer 201 and the conductive layer 592 is formed so as to fill the opening. When the resin layer 201 and the supporting substrate are separated, the conductive layer 592 and the supporting substrate are also separated at the same time, so that the conductive layer 592 as shown in FIG. 22 can be formed. For example, as illustrated in Embodiment Mode 1, a method using a light absorption layer, or a resin layer such that the back surface of the conductive layer 592 is exposed after a resin layer having a depression or a resin layer having a two-layer structure is formed. It is possible to use a method of etching a part of the above.

With such a structure, the FPC 374 connected to the display panel 200 located on the display surface side can be provided on the side opposite to the display surface. Therefore, when the display device is incorporated in an electronic device, a space for bending the FPC 374 can be omitted, and a more compact electronic device can be realized.

The above is the description of the modified example.

At least part of this embodiment can be implemented in combination with any of the other embodiments described in this specification as appropriate.

(Embodiment 3)
In this embodiment, a display module that can be manufactured using one embodiment of the present invention will be described.

A display module 8000 illustrated in FIG. 23 includes a touch panel 8004 connected to an FPC 8003, a display panel 8006 connected to an FPC 8005, a frame 8009, a printed board 8010, and a battery 8011 between an upper cover 8001 and a lower cover 8002. ..

A display device manufactured using one embodiment of the present invention can be used for the display panel 8006, for example.

The shape and dimensions of the upper cover 8001 and the lower cover 8002 can be changed as appropriate in accordance with the sizes of the touch panel 8004 and the display panel 8006.

As the touch panel 8004, a resistance film type or a capacitance type touch panel can be used by being superimposed on the display panel 8006. Alternatively, the display panel 8006 can be provided with a touch panel function without providing the touch panel 8004.

The frame 8009 has a function of protecting the display panel 8006 and a function of an electromagnetic shield for blocking an electromagnetic wave generated by the operation of the printed board 8010. The frame 8009 may also have a function as a heat dissipation plate.

The printed circuit board 8010 has a power supply circuit and a signal processing circuit for outputting a video signal and a clock signal. The power supply for supplying power to the power supply circuit may be an external commercial power supply or a power supply by a battery 8011 provided separately. The battery 8011 can be omitted when a commercial power source is used.

Further, the display module 8000 may be additionally provided with members such as a polarizing plate, a retardation plate and a prism sheet.

At least part of this embodiment can be implemented in combination with any of the other embodiments described in this specification as appropriate.

(Embodiment 4)
In this embodiment, electronic devices to which the display device of one embodiment of the present invention can be applied are described.

The display device of one embodiment of the present invention can achieve high visibility regardless of the intensity of external light. Therefore, it can be suitably used for a portable electronic device, a wearable electronic device (wearable device), an electronic book terminal, and the like.

24A and 24B show an example of a portable information terminal 800. The portable information terminal 800 includes a housing 801, a housing 802, a display portion 803, a display portion 804, a hinge portion 805, and the like.

The housing 801 and the housing 802 are connected by a hinge portion 805. The portable information terminal 800 can open the housing 801 and the housing 802 as illustrated in FIG. 24B from the folded state as illustrated in FIG.

For example, the document information can be displayed on the display portion 803 and the display portion 804 and can also be used as an electronic book terminal. Further, a still image or a moving image can be displayed on the display portion 803 and the display portion 804.

In this way, the portable information terminal 800 can be folded when being carried, and thus has excellent versatility.

Note that the housing 801 and the housing 802 may each include a power button, an operation button, an external connection port, a speaker, a microphone, and the like.

FIG. 24C illustrates an example of a mobile information terminal. A portable information terminal 810 illustrated in FIG. 24C includes a housing 811, a display portion 812, operation buttons 813, an external connection port 814, a speaker 815, a microphone 816, a camera 817, and the like.

The display portion 812 is provided with the display device of one embodiment of the present invention.

The mobile information terminal 810 includes a touch sensor on the display unit 812. All operations such as making a call or inputting a character can be performed by touching the display portion 812 with a finger, a stylus, or the like.

Further, by operating the operation button 813, the power can be turned on and off, and the type of image displayed on the display portion 812 can be switched. For example, the mail composition screen can be switched to the main menu screen.

Further, by providing a detection device such as a gyro sensor or an acceleration sensor inside the mobile information terminal 810, the orientation (vertical or horizontal) of the mobile information terminal 810 is determined and the orientation of the screen display of the display unit 812 is determined. It can be set to switch automatically. Further, switching of the screen display direction can be performed by touching the display portion 812, operating the operation button 813, inputting voice by using the microphone 816, or the like.

The portable information terminal 810 has one or more functions selected from, for example, a telephone, a notebook, an information browsing device, and the like. Specifically, it can be used as a smartphone. The portable information terminal 810 can execute various applications such as mobile phone, electronic mail, text browsing and creation, music playback, video playback, Internet communication, and games.

FIG. 24B shows an example of a camera. The camera 820 has a housing 821, a display portion 822, operation buttons 823, a shutter button 824, and the like. A detachable lens 826 is attached to the camera 820.

The display portion 822 is provided with the display device of one embodiment of the present invention.

Although the lens 826 is detachable from the housing 821 and can be replaced as the camera 820 here, the lens 826 and the housing may be integrated.

The camera 820 can capture a still image or a moving image by pressing the shutter button 824. In addition, the display portion 822 has a function as a touch panel, and an image can be taken by touching the display portion 822.

The camera 820 can be equipped with a strobe device, a viewfinder, or the like separately. Alternatively, these may be incorporated in the housing 821.

At least part of this embodiment can be implemented in combination with any of the other embodiments described in this specification as appropriate.

10 display device 11 substrate 11a substrate 12 substrate 12a substrate 21 light emission 22 reflected light 50 adhesive layer 51 adhesive layer 52 adhesive layer 61 support substrate 62 support substrate 63 support substrate 64 support substrate 70 light 100 display panel 101 resin layer 101b resin layer 101c resin Layer 101d Resin layer 102 Resin layer 110 Transistor 110a Transistor 110b Transistor 110c Transistor 111 Conductive layer 112 Semiconductor layer 113a Conductive layer 113b Conductive layer 114 Conductive layer 115 Conductive layer 120 Light emitting element 121 Conductive layer 122 EL layer 123 Conductive layer 124 Insulating layer 131 Insulation Layer 132 Insulating layer 133 Insulating layer 134 Insulating layer 135 Insulating layer 136 Insulating layer 137 Insulating layer 141 Insulating layer 141a Insulating layer 151 Adhesive layer 152 Coloring layer 200 Display panel 201 Resin layer 202 Resin layer 204 Insulating layer 210 Transistor 211 Conductive layer 212 Semiconductor Layer 213a conductive layer 213b conductive layer 220 liquid crystal element 221 conductive layer 222 liquid crystal 223 conductive layer 224a alignment film 224b alignment film 231 insulating layer 232 insulating layer 233 insulating layer 234 insulating layer 300 display device 311 electrode 311b electrode 340 liquid crystal element 351 substrate 360 light emission Element 360b Light emitting element 360g Light emitting element 360r Light emitting element 360w Light emitting element 361 Substrate 362 Display unit 364 Circuit unit 365 Wiring 366 Circuit unit 367 Wiring 372 FPC
373 IC
374 FPC
375 IC
400 display device 401 transistor 402 transistor 403 transistor 405 capacitor element 406 connection portion 407 wiring 410 pixel 411 insulating layer 412 insulating layer 413 insulating layer 414 insulating layer 415 insulating layer 416 spacer 417 adhesive layer 418 insulating layer 419 connecting layer 421 electrode 422 EL layer 423 electrode 424 optical adjustment layer 425 coloring layer 451 opening 476 insulating layer 478 insulating layer 501 transistor 503 transistor 505 capacitor 506 connecting portion 511 insulating layer 512 insulating layer 513 insulating layer 514 insulating layer 517 adhesive layer 519 connecting layer 543 connecting body 562 electrode 563 liquid crystal 564a alignment film 564b alignment film 565 colored layer 566 light-shielding layer 567 insulating layer 572 substrate 576 insulating layer 578 insulating layer 591 conductive layer 592 conductive layer 599 polarizing plate 800 portable information terminal 801 housing 802 housing 803 display portion 804 display portion 805 Hinge portion 810 Mobile information terminal 811 Housing 812 Display portion 813 Operation button 814 External connection port 815 Speaker 816 Microphone 817 Camera 820 Camera 821 Housing 822 Display portion 823 Operation button 824 Shutter button 826 Lens 8000 Display module 8001 Upper cover 8002 Lower portion Cover 8003 FPC
8004 Touch panel 8005 FPC
8006 Display panel 8009 Frame 8010 Printed circuit board 8011 Battery

Claims (13)

A display device having a first display panel, a second display panel, and a first adhesive layer,
The first display panel includes a first insulating layer, a reflective liquid crystal element, and a first transistor,
The second display panel includes a second insulating layer, a light emitting element, and a second transistor,
The first adhesive layer is provided between the first insulating layer and the second insulating layer,
The first transistor is provided on a surface of the first insulating layer opposite to the first adhesive layer,
The second transistor is provided on a surface of the second insulating layer opposite to the first adhesive layer,
A channel is formed in the oxide semiconductor between the first transistor and the second transistor,
The liquid crystal element has a function of reflecting light to the side opposite to the first insulating layer,
The light emitting element has a function of emitting light to the second insulating layer side,
Display device. In claim 1,
A first resin layer is provided between the first adhesive layer and the first insulating layer,
A second resin layer between the first adhesive layer and the second insulating layer,
The first resin layer and the second resin layer have a region having a thickness of 0.1 μm or more and 3 μm or less,
Display device. In claim 2,
The first resin layer has a first opening,
The second resin layer has a second opening,
The light emitting element has a function of emitting light through the first opening and the second opening.
Display device. In claim 2 or claim 3,
Having a third resin layer,
The liquid crystal element and the first transistor are located between the third resin layer and the first insulating layer,
The third resin layer has a third opening,
The light emitting element has a function of emitting light through the third opening.
Display device. In claim 4,
The third opening has a portion overlapping with the liquid crystal element,
The liquid crystal element has a function of reflecting light through the third opening.
Display device. Oite to claim 4 or claim 5,
The third resin layer has a thickness of 0.1 μm or more and 3 μm or less,
Display device. In any one of Claim 1 thru|or Claim 6,
A first substrate, a second substrate, a second adhesive layer, and a third adhesive layer,
The first display panel and the second display panel are located between the first substrate and the second substrate,
The second adhesive layer is located between the first substrate and the first display panel,
The third adhesive layer is located between the second substrate and the second display panel,
Display device. In claim 7,
The first substrate and the second substrate each include a resin,
Display device. In any one of Claim 1 thru|or Claim 8,
The first transistor has a first source electrode, a first drain electrode, and a first semiconductor layer,
The second transistor has a second source electrode, a second drain electrode, and a second semiconductor layer,
The first source electrode and the first drain electrode are provided in contact with an upper surface and a side end portion of the first semiconductor layer,
The second source electrode and the second drain electrode are provided in contact with an upper surface and a side end portion of the second semiconductor layer,
Display device. In any one of Claim 1 thru|or Claim 8,
The first transistor has a first source electrode, a first drain electrode, and a first semiconductor layer,
The second transistor has a second source electrode, a second drain electrode, and a second semiconductor layer,
A third insulating layer covering a part of an upper surface of the first semiconductor layer and a side end portion thereof;
A fourth insulating layer that covers a part of an upper surface and a side end portion of the second semiconductor layer,
The first source electrode and the first drain electrode, said third provided on the insulating layer, and the third through the opening provided in the insulating layer of the first semiconductor layer and electrically Connected to the
The second source electrode and the second drain electrode, the fourth is provided on the insulating layer, and the fourth of said through openings provided in the insulating layer and the second semiconductor layer and electrically Connected to the
Display device. In any one of Claim 1 thru|or Claim 8,
The first transistor has a first source electrode, a first drain electrode, and a first semiconductor layer,
The second transistor has a second source electrode, a second drain electrode, and a second semiconductor layer,
The first source electrode and the first drain electrode are provided in contact with an upper surface and a side end portion of the first semiconductor layer,
A fourth insulating layer that covers a part of an upper surface and a side end portion of the second semiconductor layer,
The second source electrode and the second drain electrode, the fourth is provided on the insulating layer, and the fourth of said through openings provided in the insulating layer and the second semiconductor layer and electrically Connected to the
Display device. In any one of Claim 1 thru|or Claim 8,
The first transistor has a first source electrode, a first drain electrode, and a first semiconductor layer,
The second transistor has a second source electrode, a second drain electrode, and a second semiconductor layer,
A third insulating layer covering a part of an upper surface of the first semiconductor layer and a side end portion thereof;
The first source electrode and the first drain electrode, said third provided on the insulating layer, and the third through the opening provided in the insulating layer of the first semiconductor layer and electrically Connected to the
The second source electrode and the second drain electrode are provided in contact with an upper surface and a side end portion of the second semiconductor layer,
Display device. In any one of Claim 9 thru|or Claim 12,
The first transistor has a first gate electrode and a second gate electrode,
The first gate electrode and the second gate electrode are provided so as to face each other with the first semiconductor layer interposed therebetween,
The second transistor has a third gate electrode and a fourth gate electrode,
The third gate electrode and the fourth gate electrode are provided so as to face each other with the second semiconductor layer interposed therebetween.
Display device.

Images