ELECTRONIC DEVICE

According to one embodiment, an electronic device includes a first bottom electrode, a second bottom electrode, a second insulating layer including a first opening portion overlapping the first bottom electrode and a second opening portion overlapping the second bottom electrode, a first organic layer disposed in the first opening portion, a second organic layer disposed in the second opening portion, a first top electrode covering the first organic layer, a second top electrode covering the second organic layer, and a sealing film covering each of the first top electrode and the second top electrode. A slit which penetrates the sealing film is formed between the first top electrode and the second top electrode.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2021-103921, filed Jun. 23, 2021, the entire contents of which are incorporated herein by reference.

FIELD

Embodiments described herein relate generally to an electronic device.

BACKGROUND

Recently, a display device which applies an organic light emitting diode (OLED) as a display element has been put into practical use. Such a display element comprises an organic layer between a first electrode and a second electrode. For example, the organic layer is formed by a vacuum deposition, and the second electrode is formed by sputtering.

For example, in case of deposition using a mask, a fine mask which comprises an opening corresponding to each pixel is applied. However, the forming accuracy of a thin film formed by vapor deposition may be reduced due to the processing accuracy of the fine mask, the deformation of openings and the like.

To solve this problem, technology which divides the organic layer and the second electrode using a pixel division structure is known.

DETAILED DESCRIPTION

In general, according to one embodiment, an electronic device comprises a base material, a first insulating layer disposed on the base material, a first bottom electrode disposed on the first insulating layer, a second bottom electrode disposed on the first insulating layer, a second insulating layer disposed on the first insulating layer and comprising a first opening portion overlapping the first bottom electrode and a second opening portion overlapping the second bottom electrode, a first organic layer disposed in the first opening portion and covering the first bottom electrode, a second organic layer disposed in the second opening portion and covering the second bottom electrode, a first top electrode covering the first organic layer, a second top electrode covering the second organic layer, and a sealing film covering each of the first top electrode and the second top electrode. A slit which penetrates the sealing film is formed between the first top electrode and the second top electrode.

In the drawings, in order to facilitate understanding, an X-axis, a Y-axis and a Z-axis orthogonal to each other are shown depending on the need. A direction parallel to the X-axis is referred to as an X-direction or a first direction. A direction parallel to the Y-axis is referred to as a Y-direction or a second direction. A direction parallel to the Z-axis is referred to as a Z-direction or a third direction. The plane defined by the X-axis and the Y-axis is referred to as an X-Y plane. When the X-Y plane is viewed, the appearance is defined as a plan view.

According to an embodiment, for example, an electronic device100is a display device comprising a display element. The display element is, for example, an organic light emitting diode (OLED) comprising an organic emitting layer. The display element can be applied as a light emitting element of an illumination device. The electronic device100may be an illumination device comprising a light emitting element.

The electronic device100of the present embodiment may be a sensor device comprising a sensor element. The sensor element is, for example, an organic photodiode (OPD) comprising an organic photoelectric conversion layer.

FIG.1shows a configuration example of the electronic device100according to the embodiment. The electronic device100comprises, on an insulating base material (substrate)10, a display portion DA which displays an image. The base material10may be a glass substrate or a resinous film having flexibility.

The display portion DA comprises a plurality of pixels PX arranged in matrix in a first direction X and a second direction Y. Each pixel PX comprises a plurality of subpixels SP1, SP2and SP3. For example, each pixel PX comprises a red subpixel SP1, a green subpixel SP2and a blue subpixel SP3. It should be noted that each pixel PX may comprise four or more subpixels. Specifically, in addition to the above three subpixels, each pixel PX may comprise a subpixel which exhibits another color, or more subpixels which exhibit other colors, such as white. A combination of colors other than the combination of red, green and blue may be applied.

Now, this specification briefly explains a configuration example of a subpixel SP included in a pixel PX.

The subpixel SP comprises a pixel circuit1, and a display element20in which driving is controlled by the pixel circuit1. The pixel circuit1comprises a pixel switch2, a drive transistor3and a capacitor4. The pixel switch2and the drive transistor3are, for example, switch elements constituted by thin-film transistors.

Regarding the pixel switch2, a gate electrode is connected to a scanning line GL, and a source electrode is connected to a signal line SL, and a drain electrode is connected to an electrode of the capacitor4and to the gate electrode of the drive transistor3.

Regarding the drive transistor3, a source electrode is connected to the other electrode of the capacitor4and to a power line PL, and a drain electrode is connected to the anode of the display element20. The cathode of the display element20is connected to a feed line FL inside the display portion DA or outside the display portion DA. The configuration of the pixel circuit1is not limited to the example shown in the figure.

The display element20is an organic light emitting diode (OLED) which is a light emitting element. For example, the subpixel SP1comprises a display element which emits light corresponding to a red wavelength. The subpixel SP2comprises a display element which emits light corresponding to a green wavelength. The subpixel SP3comprises a display element which emits light corresponding to a blue wavelength. Multicolor display can be realized since the pixel PX comprises a plurality of subpixels SP1, SP2and SP3having different display colors.

The display elements20of the subpixels SP1, SP2and SP3may be configured to emit the light of the same color. This configuration enables monochromatic display.

When the display element20of each of the subpixels SP1, SP2and SP3is configured to emit white light, a color filter facing each display element20may be provided. For example, the subpixel SP1comprises a red color filter facing the display element20. The subpixel SP2comprises a green color filter facing the display element20. The subpixel SP3comprises a blue color filter facing the display element20. By this configuration, multicolor display can be realized.

Alternatively, when the display element20of each of the subpixels SP1, SP2and SP3is configured to emit ultraviolet light, multicolor display can be realized by providing a light conversion layer facing each display element20.

FIG.2is a plan view showing an example of each pixel PX shown inFIG.1.

Each of the subpixels SP1, SP2and SP3which constitute a pixel PX is formed in substantially a rectangular shape extending in the second direction Y. The subpixels SP1, SP2and SP3are arranged in the first direction X. The outline of each subpixel corresponds to the outline of an emitting area EA in the display element20. However, the outline is shown in a simplified manner and does not necessarily reflect the actual shape. Here, it is assumed that the emitting area EA is formed in a rectangular shape having short sides extending in the first direction X and long sides extending in the second direction Y.

As seen in plan view, an insulating layer12which is described in detail later is formed in a grating shape extending in the first direction X and the second direction Y, and surrounds each of the subpixels SP1, SP2and SP3or the display element20of each subpixel. Such an insulating layer12may be referred to as a rib, partition, bank and the like. The insulating layer12comprises a plurality of opening portions OP including opening portions OP1and OP2. The emitting areas EA are formed in the opening portions OP of the insulating layer12. The opening portions OP are arranged in matrix in the first direction X and the second direction Y.

As seen in plan view, a partition30which is described in detail later is formed in a grating shape extending in the first direction X and the second direction Y and is disposed on the insulating layer12. Each of the subpixels SP1, SP2and SP3is surrounded by the partition30.

The shape of the partition30is not limited to the example shown inFIG.2, and may be another shape such as a stripe shape. The layout of the subpixels SP or opening portions OP is not limited to the example shown inFIG.2, either.

FIG.3shows an example of the configuration of the display element20.

The display element20comprises a bottom electrode (first electrode) E1, an organic layer OR and a top electrode (second electrode) E2. The organic layer OR is disposed on the bottom electrode E1. The top electrode E2is disposed on the organic layer OR. The organic layer OR comprises a carrier adjustment layer CA1, a light emitting layer EL and a carrier adjustment layer CA2. The carrier adjustment layer CA1is located between the bottom electrode E1and the light emitting layer EL. The carrier adjustment layer CA2is located between the light emitting layer EL and the top electrode E2. The carrier adjustment layers CA1and CA2include a plurality of functional layers.

Here, this specification explains an example in which the bottom electrode E1corresponds to an anode and the top electrode E2corresponds to a cathode.

The carrier adjustment layer CA1includes a hole injection layer F11, a hole transport layer F12, an electron blocking layer F13and the like as functional layers. The hole injection layer F11is disposed on the bottom electrode E1. The hole transport layer F12is disposed on the hole injection layer F11. The electron blocking layer F13is disposed on the hole transport layer F12. The light emitting layer EL is disposed on the electron blocking layer F13.

The carrier adjustment layer CA2includes a hole blocking layer F21, an electron transport layer F22, an electron injection layer F23and the like as functional layers. The hole blocking layer F21is disposed on the light emitting layer EL. The electron transport layer F22is disposed on the hole blocking layer F21. The electron injection layer F23is disposed on the electron transport layer F22. The top electrode E2is disposed on the electron injection layer F23.

In addition to the functional layers described above, the carrier adjustment layers CA1and CA2may include other functional layers such as a carrier generation layer as needed, or at least one of the above functional layers may be omitted in the carrier adjustment layers CA1and CA2.

FIG.4is a cross-sectional view showing a configuration example of the electronic device100along the A-B line shown inFIG.2.

The electronic device100comprises the base material10, an insulating layer (first insulating layer)11, the insulating layer (second insulating layer)12, the display element20, the partition30and a sealing film50.

From the viewpoint of providing the flexible electronic device100, the base material10is a resinous film. The insulating layer11is disposed on the base material10and corresponds to an underlayer of the display element20. The pixel circuit1shown inFIG.1is disposed on the base material10and is covered with the insulating layer11. The insulating layer12is disposed on the insulating layer11.

We now focus on two display elements adjacent to each other in the first direction X. For convenience, the display element located on the left side of the figure is denoted as a display element21, and the display element located on the right side of the figure is denoted as a display element22.

The display element21comprises a bottom electrode (first bottom electrode) E11, an organic layer (first organic layer) OR1and a top electrode (first top electrode) E21.

The display element22comprises a bottom electrode (second bottom electrode) E12, an organic layer (second organic layer) OR2and a top electrode (second top electrode) E22.

The bottom electrodes E11and E12are disposed on the insulating layer11, and are arranged so as to be spaced apart from each other in the first direction X. Each of the bottom electrodes E11and E12is an electrode arranged for each subpixel or each display element, and is electrically connected to the drive transistor3shown inFIG.1. These bottom electrodes E11and E12may be referred to as pixel electrodes, anodes, etc.

The bottom electrodes E11and E12are transparent electrodes formed of, for example, a transparent conductive material such as indium tin oxide (ITO) or indium zinc oxide (IZO). The bottom electrodes E11and E12may be metal electrodes formed of a metal material such as silver or aluminum. Alternatively, the bottom electrodes E11and E12may be stacked layer bodies of transparent electrodes and metal electrodes. For example, the bottom electrodes E11and E12may be configured as stacked layer bodies formed by stacking a transparent electrode, a metal electrode and a transparent electrode in order, or may be configured as stacked layer bodies of four or more layers.

The insulating layer12is disposed between the bottom electrode E11and the bottom electrode E12. The insulating layer12comprises the opening portion OP1and the opening portion OP2. The insulating layer12is formed so as to define the subpixels or display elements21and22. The insulating layer12is, for example, an inorganic insulating layer formed of a silicon nitride and the like.

The opening portion OP1is formed in an area overlapping the bottom electrode E11, and is a through-hole which penetrates the insulating layer12such that the bottom electrode E11is exposed from the insulating layer12. The peripheral portion of the bottom electrode E11is covered with the insulating layer12. The central portion of the bottom electrode E11is exposed from the insulating layer12in the opening portion OP1.

The opening portion OP2is formed in an area overlapping the bottom electrode E12, and is a through-hole which penetrates the insulating layer12such that the bottom electrode E12is exposed from the insulating layer12. The peripheral portion of the bottom electrode E12is covered with the insulating layer12. The central portion of the bottom electrode E12is exposed from the insulating layer12in the opening portion OP2.

The organic layer OR1is disposed in the opening portion OP1and covers the bottom electrode E11. The organic layer OR2is disposed in the opening portion OP2and covers the bottom electrode E12. In the example shown inFIG.4, a part of the organic layer OR1and a part of the organic layer OR2are also disposed on the top surface U1of the insulating layer12. Each of these organic layers OR1and OR2is arranged for a subpixel or display element in a manner similar to that of the bottom electrodes E11and E12. On the insulating layer12, the organic layer OR2is spaced apart from the organic layer OR1.

Each of the organic layers OR1and OR2includes a light emitting layer. The light emitting layer of the organic layer OR1may be formed of the same material as the light emitting layer of the organic layer OR2(in other words, the organic layer OR1and the organic layer OR2may have the same light emission color). Or, the light emitting layer of the organic layer OR1may be formed of a material different from that of the light emitting layer of the organic layer OR2(in other words, the organic layer OR1and the organic layer OR2may have light emission colors different from each other).

The top electrode E21is disposed on the organic layer OR1and covers the entire part of the organic layer OR1including the peripheral portion of the organic layer OR1. The top electrode E21is in contact with the top surface U1outside the peripheral portion of the organic layer OR1. Of the organic layer OR1, a portion located between the bottom electrode E11and the top electrode E21without intervention of the insulating layer12is configured to form an emitting area of the display element21. Of the organic layer OR1, a portion located between the insulating layer12and the top electrode E21hardly emits light.

The top electrode E22is disposed on the organic layer OR2and covers the entire part of the organic layer OR2including the peripheral portion of the organic layer OR2. The top electrode E22is in contact with the top surface U1outside the organic layer OR2. The top electrode E22is spaced apart from the top electrode E21. Of the organic layer OR2, a portion located between the bottom electrode E12and the top electrode E22without intervention of the insulating layer12is configured to form an emitting area of the display element22. Of the organic layer OR2, a portion located between the insulating layer12and the top electrode E22hardly emits light.

Each of these top electrodes E21and E22is an electrode arranged for a subpixel or display element. As described later, the top electrodes E21and E22are electrically connected to each other through the partition30. These top electrodes E21and E22may be referred to as common electrodes, counter-electrodes, cathodes, etc.

The top electrodes E21and E22are, for example, semi-transparent metal electrodes formed of a metal material such as magnesium or silver. The top electrodes E21and E22may be transparent electrodes formed of a transparent conductive material such as ITO or IZO. Alternatively, the top electrodes E21and E22may be stacked layer bodies of transparent electrodes and metal electrodes.

The partition30is located between the display element21and the display element22, and is disposed on the insulating layer12. On the top surface U1, the partition30is located between the organic layer OR1and the organic layer OR2, and is spaced apart from the organic layers OR1and OR2. The partition30is located between the top electrode E21and the top electrode E22, and is in contact with the top electrodes E21and E22.

The partition30comprises a first layer31and a second layer32disposed on the first layer31.

The first layer31is, for example, a conductive layer formed of a metal material. The first layer31is located on the insulating layer12and is in contact with the top surface U1. The first layer31comprises a side surface (first side surface) S11facing the opening portion OP1(or the display element21), a side surface (second side surface) S12facing the opening portion OP2(or the display element22), and a top surface U11between the side surface S11and the side surface S12. The top electrode E21is in contact with the side surface S11, and the top electrode E22is in contact with the side surface S12. By this configuration, the top electrodes E21and E22which are adjacent to each other across the intervening partition30are electrically connected to each other. In other words, the first layer31functions as the feed line FL shown inFIG.1. Apart from the first layer31, a feed line FL may be provided in the display portion DA and electrically connected to the top electrode of each display element.

The second layer32is formed of a material different from that of the first layer31, and is formed of, for example, an insulating material. For example, the second layer32is an inorganic insulating layer formed of a silicon nitride, etc., which is the same material as the insulating layer12. The second layer32is in contact with the top surface U11. The second layer32extends from the side surface S11toward the opening portion OP1on the left side of the figure, and further extends from the side surface S12toward the opening portion OP2on the right side of the figure.

On the partition30, as deposits, a layer41formed of the same material as the organic layer OR1and a layer42formed of the same material as the top electrode E21are stacked. The layer41is spaced apart from the organic layers OR1and OR2. The layer42is spaced apart from the top electrodes E21and E22.

As this partition30is formed, the organic layers OR1and OR2and the top electrodes E21and E22are formed without applying a fine mask.

In other words, the organic layers OR1and OR2are formed by, for example, a vacuum deposition method, using the partition30as a mask. At this time, vapor from an evaporation source passes through the area where the partition30does not exist, and reaches the upper side of the bottom electrodes E11and E12. Vapor from the evaporation source does not reach the shadow area of the partition30.

Similarly, the top electrodes E21and E22are formed by, for example, sputtering, using the partition30as a mask. At this time, particles from a target passes through the area where the partition30does not exist, and reaches the upper side of the organic layers OR1and OR2.

This configuration reduces the production cost compared to the case where a fine mask is applied, and also eliminates the need for processes such as fine mask alignment. Thus, the organic layers OR1and OR2and the top electrodes E21and E22can be easily formed in a desired shape. In addition, in the display elements21and22, an emitting area can be formed in a predetermined area. Furthermore, undesired light emission in an area overlapping the insulating layer12is suppressed.

The sealing film50for protecting the display elements21and22from moisture, etc., covers the top electrodes E21and E22. In this sealing film50, a slit ST is formed so as to penetrate the sealing film50between the top electrode E21and the top electrode E22. In the example shown inFIG.4, the slit ST also penetrates the second layer32of the partition30, and the top surface U11of the first layer31is exposed from the slit ST.

Now, the sealing film50is described more specifically.

The sealing film50comprises an inorganic insulating film (first inorganic insulating film)51, an organic insulating film52and an inorganic insulating film (second inorganic insulating film)53. The organic insulating film52is disposed on the inorganic insulating film51and covered with the inorganic insulating film53.

The inorganic insulating film51is divided by the slit ST and covers the top electrodes E21and E22individually. In other words, on the left side of the figure, the inorganic insulating film51is in contact with the top electrode E21and the side surface S11of the first layer31, and overlaps the second layer32and the layers41and42. On the right side of the figure, the inorganic insulating film51is in contact with the top electrode E22and the side surface S12of the first layer31, and overlaps the second layer32and the layers41and42. The inorganic insulating film51is formed of, for example, a transparent insulating material such as a silicon nitride.

The organic insulating film52is also divided by the slit ST and is disposed on each of the inorganic insulating film51covering the top electrode E21and the inorganic insulating film51covering the top electrode E22. On the left side of the figure, the organic insulating film52overlaps the top electrode E21and is in contact with the inorganic insulating film51. On the right side of the figure, the organic insulating film52overlaps the top electrode E22and is in contact with the inorganic insulating film51. The organic insulating film52is formed of, for example, a transparent resinous material such as an acrylic resin.

The inorganic insulating film53is also divided by the slit ST and covers each of the organic insulating film52overlapping the top electrode E21and the organic insulating film52overlapping the top electrode E22. On the left side of the figure, the inorganic insulating film53overlaps the top electrode E21, and is in contact with the organic insulating film52, and is in contact with the inorganic insulating film51on the partition30. On the right side of the figure, the inorganic insulating film53overlaps the top electrode E22, and is in contact with the organic insulating film52, and is in contact with the inorganic insulating film51on the partition30. The inorganic insulating film53is formed of, for example, the same material as the inorganic insulating film51, and is formed of a transparent insulating material such as a silicon nitride.

As explained above, the electronic device100can be provided so as to be flexible by forming the slit ST which penetrates the sealing film50and dividing the sealing film50for each display element. In addition, compared to the case where the slit ST is not formed in the sealing film50, it is possible to reduce damage to the sealing film50when the electronic device100is deformed. Thus, predetermined sealing performance can be maintained.

FIG.5is a cross-sectional view showing another configuration example of the electronic device100along the A-B line shown inFIG.2.

The configuration example shown inFIG.5is different from the configuration example shown inFIG.4in respect that the slit ST further penetrates the first layer31and the insulating layer12. In other words, the insulating layer12and the partition30are divided by the slit ST. In the example shown in the figure, the insulating layer11is exposed from the slit ST.

In this configuration example, since the first layer31which is a conductive layer and the insulating layer12which is an inorganic insulating layer are divided by the slit ST, it is possible to provide the electronic device100so as to be more flexible than the configuration example shown inFIG.4. Although not shown in the figure, the slit ST may be configured to include a recess portion which penetrates the sealing film50and does not penetrate the first layer31, or may be configured to include a recess portion which penetrates the sealing film50and the first layer31and does not penetrate the insulating layer12.

FIG.6is a plan view showing a configuration example of the slit ST.

The slit ST comprises a first portion STX extending in the first direction X parallel to the insulating layer12, and a second portion STY extending in the second direction Y parallel to the insulating layer12. The slit ST is formed in a grating shape.

FIG.7is a plan view showing another configuration example of the slit ST.

The slit ST extends in the first direction X parallel to the insulating layer12and is formed in a stripe shape.

FIG.8is a plan view showing another configuration example of the slit ST.

The slit ST extends in the second direction Y parallel to the insulating layer12and is formed in a stripe shape.

In each of the configuration examples shown inFIG.6toFIG.8, the slit ST penetrates at least the sealing film50. The slit ST may penetrate the second layer32as shown inFIG.4, or may penetrate the insulating layer12, the first layer31and the second layer32as shown inFIG.5. The shape of the slit ST is not limited to a continuous straight line, and may be a dotted line.

According to the above embodiment, a flexible electronic device can be provided.

All of the electronic devices that can be implemented by a person of ordinary skill in the art through arbitrary design changes to the electronic device described above as the embodiment of the present invention come within the scope of the present invention as long as they are in keeping with the spirit of the present invention.

Various modification examples which may be conceived by a person of ordinary skill in the art in the scope of the idea of the present invention will also fall within the scope of the invention. For example, even if a person of ordinary skill in the art arbitrarily modifies the above embodiment by adding or deleting a structural element or changing the design of a structural element, or by adding or omitting a step or changing the condition of a step, all of the modifications fall within the scope of the present invention as long as they are in keeping with the spirit of the invention.

Further, other effects which may be obtained from the above embodiment and are self-explanatory from the descriptions of the specification or can be arbitrarily conceived by a person of ordinary skill in the art are considered as the effects of the present invention as a matter of course.