JP2019046718A - Display device - Google Patents

Abstract

To provide a reliable display device.SOLUTION: A display device includes a display area provided on a substrate, a first inorganic insulating layer provided on the display area, a first organic insulating layer provided on the first inorganic insulating layer, and a second inorganic insulating layer provided on the first organic insulating layer, and the first inorganic insulating layer includes a first region and a second region thinner than the first region in thickness, and the second inorganic insulating layer includes a third region and a fourth region thicker than the third region in film thickness, and the second region is disposed along the first direction, and the fourth region is disposed along the first direction, and the second region does not overlap the fourth region.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a foldable display device.

  Conventionally, an organic EL display (Organic Electroluminescence Display) using an organic electroluminescence material (organic EL material) as a light emitting element (organic EL element) of a display unit is known as a display device. Unlike a liquid crystal display device or the like, an organic EL display device is a so-called self-luminous display device that realizes display by causing an organic EL material to emit light.

  In recent years, in such an organic EL display device, in order to protect the light emitting element from moisture or the like, it has been studied to cover the light emitting element with a sealing film. For example, Patent Document 1 discloses a configuration in which an organic light-emitting element is provided with a barrier layer in which inorganic insulating layers that prevent permeation of moisture and oxygen and organic insulating layers that suppress stress are alternately stacked. Yes. As a result, it is possible to prevent moisture and oxygen from permeating into the organic light emitting element and improve the bending resistance of the panel.

JP2003-17244

  In the organic EL display device, a flexible display in which an organic EL element is provided on a flexible resin substrate such as plastic has been developed. However, when the flexible display is repeatedly bent, the inorganic insulating layer provided as a barrier layer for shielding the organic EL element from moisture and oxygen may be broken. If the inorganic insulating layer as the barrier layer is broken, there is a problem that the organic EL element is deteriorated due to moisture or oxygen entering from the outside, and the reliability of the organic EL display device is lowered.

  In view of the above problems, an object is to provide a display device with high reliability.

  A display device according to an embodiment of the present invention includes a display area provided on a substrate, a first inorganic insulating layer provided on the display area, and a first area provided on the first inorganic insulating layer. A first organic insulating layer and a second inorganic insulating layer provided on the first organic insulating layer, the first inorganic insulating layer being a second region having a thickness smaller than that of the first region. And the second inorganic insulating layer includes a third region and a fourth region having a thickness smaller than that of the third region, and the second region is disposed along the first direction. The fourth area is arranged along the first direction, and the second area does not overlap the fourth area.

  A display device according to an embodiment of the present invention includes a display region provided on a substrate, a first inorganic insulating layer provided on the display region, and a first organic insulating layer provided on the first inorganic insulating layer. And a second inorganic insulating layer provided on the first organic insulating layer, wherein the first inorganic insulating layer includes a first region and a second region having a thickness smaller than that of the first region. The second inorganic insulating layer has a third region and a fourth region having a thickness smaller than that of the third region, and the second region is disposed along the first direction; The region is arranged along a second direction that intersects the first direction.

  A display device according to an embodiment of the present invention includes a display region provided on a substrate, a first inorganic insulating layer provided on the display region, and a first organic insulating layer provided on the first inorganic insulating layer. And a second inorganic insulating layer provided on the first organic insulating layer, the first organic insulating layer has convex portions at a first interval along the first direction, and the second The inorganic insulating layer has a first region and a second region having a thickness smaller than that of the first region, and the second region is provided in contact with a corner of the convex portion.

It is the top view which showed the structure of the display apparatus which concerns on one Embodiment of this invention. It is sectional drawing along the A1-A2 line shown in FIG. It is the top view which showed the structure of the display apparatus which concerns on one Embodiment of this invention. It is sectional drawing of the state which bent the display apparatus. It is sectional drawing of the manufacturing method of the display apparatus which concerns on one Embodiment of this invention. It is sectional drawing of the manufacturing method of the display apparatus which concerns on one Embodiment of this invention. It is sectional drawing of the manufacturing method of the display apparatus which concerns on one Embodiment of this invention. It is sectional drawing of the manufacturing method of the display apparatus which concerns on one Embodiment of this invention. It is sectional drawing of the manufacturing method of the display apparatus which concerns on one Embodiment of this invention. It is sectional drawing of the manufacturing method of the display apparatus which concerns on one Embodiment of this invention. It is sectional drawing of the display apparatus which concerns on one Embodiment of this invention. It is sectional drawing of the display apparatus which concerns on one Embodiment of this invention. It is sectional drawing of the display apparatus which concerns on one Embodiment of this invention. It is the top view which showed the structure of the display apparatus which concerns on one Embodiment of this invention. It is the top view which showed the structure of the display apparatus which concerns on one Embodiment of this invention. It is sectional drawing of the display apparatus which concerns on one Embodiment of this invention. It is sectional drawing of the display apparatus which concerns on one Embodiment of this invention. It is sectional drawing of the display apparatus which concerns on one Embodiment of this invention. It is sectional drawing of the manufacturing method of the display apparatus which concerns on one Embodiment of this invention. It is sectional drawing of the manufacturing method of the display apparatus which concerns on one Embodiment of this invention. It is sectional drawing of the manufacturing method of the display apparatus which concerns on one Embodiment of this invention. It is the top view to which a part of display area of the display device concerning one embodiment of the present invention was expanded. It is sectional drawing along the C1-C2 line shown in FIG. It is sectional drawing when a crack arises in the sealing film of a display apparatus. It is sectional drawing of the display apparatus which concerns on one Embodiment of this invention. It is sectional drawing of the pixel of the display apparatus which concerns on one Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the present invention can be implemented in various modes without departing from the gist thereof, and is not construed as being limited to the description of the embodiments exemplified below. In addition, with regard to the drawings, in order to clarify the explanation, the width, thickness, shape, and the like of each part may be schematically represented as compared to the actual mode. The interpretation of the invention is not limited. Furthermore, in the present specification and each drawing, the same or similar elements as those described with reference to the previous drawings may be denoted by the same reference numerals, and redundant description may be omitted.

  In the present invention, when a plurality of films are formed by processing a certain film, the plurality of films may have different functions and roles. However, the plurality of films are derived from films formed as the same layer in the same process, and have the same layer structure and the same material. Therefore, these plural films are defined as existing in the same layer.

  Note that in the present specification, expressions such as “upper” and “lower” when describing the drawings represent relative positional relationships between the structure of interest and other structures. In the present specification, in a side view, a direction from an insulating surface to be described later toward the sealing film is defined as “up”, and the opposite direction is defined as “down”. In the present specification and claims, in expressing a mode of disposing another structure on a certain structure, when simply describing “on top”, unless otherwise specified, It includes both the case where another structure is disposed immediately above and a case where another structure is disposed via another structure above a certain structure.

(First embodiment)
A display device according to the present invention will be described with reference to FIGS. 1 to 6C.

[Configuration of display device]
FIG. 1 is a schematic diagram showing a configuration of a display device 100 according to an embodiment of the present invention, and shows a schematic diagram when the display device 100 is viewed in plan. In this specification, a state in which the display device 100 is viewed from a direction perpendicular to the screen (display area) is referred to as “plan view”.

  As illustrated in FIG. 1, the display device 100 includes a display region 103, a scanning line driver circuit 104, and a driver IC 106 that are formed on an insulating surface. In the display region 103, a light-emitting element having an organic layer made of an organic material is arranged. In addition, a peripheral area 110 surrounds the display area 103. The driver IC 106 functions as a control unit that gives a signal to the scanning line driving circuit 104. In the driver IC 106, a signal line driver circuit is incorporated. The driver IC 106 is provided on the flexible printed circuit board 108 and externally attached thereto, but may be disposed on the circuit board 101. The flexible printed circuit board 108 is connected to the terminals 107 provided in the peripheral area 110.

  Here, the insulating surface is the surface of the substrate 101. The substrate 101 supports each layer such as a pixel electrode or an insulating layer provided on the surface. As the substrate 101, a flexible substrate (polyimide, polyethylene terephthalate, polyethylene naphthalate, triacetyl cellulose, cyclic olefin copolymer, cycloolefin polymer, or other flexible resin substrate) can be used. By using a flexible resin substrate, the display device can be bent. The substrate 101 is preferably a material that transmits light. The counter substrate 102 can also be a substrate similar to the substrate 101. Note that when there is no need to bend the display device, a metal substrate, a ceramic substrate, a semiconductor substrate, or the like can be used.

  In the display area 103 shown in FIG. 1, a plurality of pixels 109 are arranged in a matrix so as to extend in directions that intersect each other (for example, an x direction and a y direction orthogonal to each other). Each pixel 109 includes a pixel electrode to be described later, a part of the pixel electrode (anode), a light emitting element including an organic layer (light emitting unit) including a light emitting layer stacked on the pixel electrode, and a cathode (cathode). including. Each pixel 109 is supplied with a data signal corresponding to the image data from the signal line driver circuit. In accordance with these data signals, a transistor electrically connected to a pixel electrode provided in each pixel 109 can be driven to perform screen display according to image data. As the transistor, typically, a thin film transistor (TFT) can be used. However, not only the thin film transistor but any element having a current control function may be used.

  The display device is provided with a sealing film for protecting the light emitting element from moisture and oxygen. As the sealing film, for example, a configuration in which inorganic insulating layers and organic insulating layers are alternately stacked is employed. However, when the display device is a foldable display device, the inorganic insulating layer may be cracked by repeatedly bending the display device. When moisture or oxygen enters from a location where a crack occurs in the inorganic insulating layer, the light-emitting layer of the light-emitting element deteriorates, and the light-emitting element does not emit light. Further, the reliability of the display device may be reduced due to deterioration of the light emitting element.

  Furthermore, since cracks generated in the inorganic insulating layer are generated randomly, it is not possible to control the intrusion route of moisture and oxygen. Thus, moisture or oxygen may reach the light emitting element immediately from the place where the crack occurs. As a result, since the light emitting element is quickly deteriorated, the reliability of the display device is lowered.

  In addition, although the bending resistance of the display device is improved by reducing the thickness of the inorganic insulating layer, the function of allowing moisture and oxygen to pass therethrough is reduced, so that moisture and oxygen may enter the light-emitting element. .

  In view of this, the display device 100 according to the present invention has a configuration in which thin regions are provided at regular intervals in the inorganic insulating layer constituting the sealing film.

  FIG. 2 is a cross-sectional view taken along the line A1-A2 of the display device 100 shown in FIG. Further, the case where the display device 100 can be bent along the line B1-B2 will be described.

  In the display device 100 illustrated in FIG. 2, an element formation layer 160 is provided over a substrate 101. The element formation layer 160 is a layer in which a light emitting element and a transistor for driving the light emitting element are provided. The structure of the light emitting element and the transistor provided in the element formation layer 160 will be described in detail later.

  A sealing film 140 is provided on the element formation layer 160. In FIG. 2, a structure in which the sealing film 140 includes an inorganic insulating layer 131, an organic insulating layer 132, and an inorganic insulating layer 133 is described. In the present invention, the number of inorganic insulating layers and organic insulating layers is particularly limited. Not.

  In the sealing film 140, the inorganic insulating layer 131 and the inorganic insulating layer 133 are layers that suppress the permeation of moisture and oxygen because of high molecular density and low moisture diffusion constant. The organic insulating layer 132 is a layer having bending resistance. As shown in FIG. 2, by providing the organic insulating layer 132 between the inorganic insulating layer 131 and the inorganic insulating layer 133, moisture and oxygen are transmitted through the inorganic insulating layer 131 and the inorganic insulating layer 133. The organic insulating layer 132 can suppress the stress generated when the display device 100 is bent.

As the inorganic insulating layer 131 and the inorganic insulating layer 133, for example, a silicon nitride (Si _x N _y ), a silicon oxynitride (SiO _x N _y ), a silicon nitride oxide (SiN _x O _y ), an oxide is formed by a CVD method or a sputtering method. It is formed using a film of aluminum (Al _x O _y ), aluminum nitride (Al _x N _y ), aluminum oxynitride (Al _x O _y N _z ), aluminum nitride oxide (Al _x N _y O _z ), or the like. (X, y, and z are arbitrary). The thickness of the inorganic insulating layer 131 is preferably, for example, 500 nm to 1000 nm, and the thickness of the inorganic insulating layer 133 is preferably, for example, 500 nm to 1000 nm.

  As the organic insulating layer 132, for example, an acrylic resin, an epoxy resin, a polyimide resin, a silicone resin, a fluorine resin, a siloxane resin, or the like can be used.

In addition, when the water vapor transmission rate (WVTR) as the sealing film 140 is low, moisture hardly enters. The water vapor transmission rate required for the sealing film 140 of the organic EL display device is preferably 1 × 10 ⁻⁵ (g / m ² / day (40 ° C. 90% RH)) or less. The water vapor transmission rate refers to the amount of water vapor that passes through a 1 m ² film in 24 hours, expressed in grams.

The inorganic insulating layer 131 and the inorganic insulating layer 133 preferably have a water vapor transmission rate of 1 × 10 ⁻⁵ (g / m ² / day (40 ° C. 90% RH)) or more. By setting the water vapor transmission rate of the inorganic insulating layer 131 and the inorganic insulating layer 133 to 1 × 10 ⁻⁵ (g / m ² / day (40 ° C. 90% RH)) or less, water and oxygen can be added to the inorganic insulating layer 131 and Transmission through the inorganic insulating layer 133 can be suppressed. Thus, water and oxygen can be prevented from entering the light-emitting element provided in the element formation layer 160. The organic insulating layer 132 preferably has a water vapor transmission rate of 1 × 10 ⁰ to 1 × 10 ⁻⁵ (g / m ² / day (40 ° C. 90% RH)) or more. The thickness of the organic insulating layer 132 is preferably 5 μm or more and 15 μm or less.

  Even when the display device 100 is repeatedly bent and a crack is generated in the sealing film 140, if the distance until moisture or oxygen reaches the light-emitting element is sufficiently long, the reliability of the display device 100 is improved. Does not affect sex. Therefore, in the display device 100 according to the present embodiment, when the display device 100 is bent, even if a crack occurs in the sealing film, a sufficient distance is required for moisture and oxygen to reach the light emitting element. A portion where a crack is likely to occur is formed in the inorganic insulating layer so as to be long.

  As shown in FIG. 2, regions 151 having a small film thickness are provided in the inorganic insulating layer 131 along one direction of the display region 103 at a constant interval m. The inorganic insulating layer 133 is also provided with regions 152 having a small film thickness along a direction of the display region 103 at a constant interval n. In addition, as shown in FIG. 2, it is preferable that the constant interval m of the region 151 and the constant interval n of the region 152 have the same length, and the region 152 is provided in the middle of the adjacent region 151. .

  By providing the thin region 151 in the inorganic insulating layer 131 and the thin region 152 in the inorganic insulating layer 133, when the display device is repeatedly bent, cracks are likely to occur in the region 151 and the region 152. . Thereby, the bending stress concerning the inorganic insulating layer 131 and the inorganic insulating layer 133 can be relieved. Further, since the organic insulating layer 132 is a flexible material, a crack generated in the inorganic insulating layer 131 and the inorganic insulating layer 133 does not propagate to the organic insulating layer 132. Therefore, moisture and oxygen entering from the crack generated in the inorganic insulating layer 133 follow the path of the organic insulating layer 132 and progress to the crack of the inorganic insulating layer 131. By providing a location where a crack is generated in the sealing film 140 in advance, the amount of moisture passing through the organic insulating layer 132 can be controlled as compared with a case where the crack is generated randomly in the sealing film 140.

  That is, moisture or oxygen that penetrates vertically into the sealing film 140 can be prevented from entering by the inorganic insulating layer 133 and the inorganic insulating layer 131. Further, moisture and oxygen entering from cracks generated in the inorganic insulating layer 133 and the inorganic insulating layer 131 follow the path of the organic insulating layer 132. Therefore, the time until moisture and oxygen reach the light emitting element can be increased. Thereby, the reliability of the display device can be improved.

  The thin region 151 provided in the inorganic insulating layer 131 and the thin region 152 provided in the inorganic insulating layer 133 are recessed.

  FIG. 3 shows the case where the region 151 is provided in the inorganic insulating layer 131 and the case where the region 152 is provided in the inorganic insulating layer 133. As illustrated in FIG. 3, the region 151 and the region 152 are provided along the x direction of the display region 103.

  2 and 3, it is preferable that the region 151 where the inorganic insulating layer 131 is thin does not overlap with the region 152 where the inorganic insulating layer 133 is thin. When the region 151 where the inorganic insulating layer 131 is thin and the region 152 where the inorganic insulating layer 133 is thin overlap, the distance until moisture or oxygen reaches the light emitting element when the sealing film is broken. However, it becomes approximately the same as the film thickness of the organic insulating layer 132.

  FIG. 4 shows a case where the display device is repeatedly bent along the line B1-B2 shown in FIG. 1 to cause a crack in the sealing film. As shown in FIG. 4, the counter substrate 102, the inorganic insulating layer 133, the organic insulating layer 132, and the inorganic insulating layer 131 are cracked. The black circles shown in FIG. 4 indicate water, and the arrows indicate water intrusion paths. Water enters the display device from cracks generated in the inorganic insulating layer 131 and the inorganic insulating layer 133. Therefore, moisture and oxygen entering from the crack generated in the inorganic insulating layer 133 follow the path of the organic insulating layer 132 and progress to the crack of the inorganic insulating layer 131. By providing the region 151 where the inorganic insulating layer 131 is thin so as not to overlap the region 152 where the inorganic insulating layer 133 is thin, a portion where a crack is generated is provided apart. As a result, even when the sealing film is cracked when the display device 100 is bent, the distance until moisture or oxygen reaches the light emitting element is sufficiently long. Accordingly, the time until the light-emitting element is deteriorated by moisture or oxygen can be extended, so that the reliability of the display device can be improved.

  Thus, in the display device 100 according to the present embodiment, the path through which moisture and oxygen enter is controlled by controlling the location where the inorganic insulating layer breaks in advance. As shown in FIG. 4, even if the inorganic insulating layer has cracks, the distance until moisture and oxygen reach the light emitting element can be made sufficiently long compared to the case where cracks occur randomly. it can. Thereby, since the time until the light emitting element is deteriorated can be lengthened, the reliability of the display device 100 can be improved.

[Manufacturing method of display device]
Next, a method for manufacturing the display device according to the present embodiment will be described with reference to FIGS. 5A to 5F. 5A to 5F are cross-sectional views taken along line A1-A2 of the display device 100 shown in FIG.

  As illustrated in FIG. 5A, the element formation layer 160 is formed on the substrate 101. As the substrate 101, a flexible substrate (polyimide, polyethylene terephthalate, polyethylene naphthalate, triacetyl cellulose, cyclic olefin copolymer, cycloolefin polymer, or other flexible resin substrate) can be used. By using a flexible resin substrate, the display device can be bent. The substrate 101 is preferably a material that transmits light.

  A transistor and a light-emitting element driven by the transistor are formed as the element formation layer 160 over the substrate 101. Here, the structure of the transistor and the light-emitting element can be manufactured using a known method, and thus detailed description thereof is omitted.

Next, as illustrated in FIG. 5B, the inorganic insulating layer 131 is formed over the element formation layer 160. Examples of the inorganic insulating layer 131 include silicon nitride (Si _x N _y ), silicon oxynitride (SiO _x N _y ), silicon nitride oxide (SiN _x O _y ), and aluminum oxide (Al _x ) by CVD or sputtering. O _y ), aluminum nitride (Al _x N _y ), aluminum oxynitride (Al _x O _y N _z ), aluminum nitride oxide (Al _x N _y O _z ), and the like (x) , Y, and z are arbitrary). The inorganic insulating layer 131 and the inorganic insulating layer 133 preferably have a water vapor transmission rate of 1 × 10 ⁻⁵ (g / m ² / day (40 ° C. 90% RH)) or less. The light-emitting element provided in the element formation layer 160 by setting the water vapor permeability of the inorganic insulating layer 131 and the inorganic insulating layer 133 to 1 × 10 ⁻⁵ (g / m ² / day (40 ° C. 90% RH)) or less. In addition, water and oxygen can be prevented from entering. Moreover, it is preferable that the film thickness of the inorganic insulating layer 131 be 500 nm or more and 1000 nm or less, for example.

  Next, as illustrated in FIG. 5C, a thin region 151 is formed in the inorganic insulating layer 131. The region 151 can be formed, for example, by irradiating the inorganic insulating layer 131 with laser light in the ultraviolet region. Alternatively, a mask can be formed over the inorganic insulating layer 131 and dry etching can be performed. In addition, a cutout may be formed in the inorganic insulating layer 131 with a microprobe. The thin regions 151 provided in the inorganic insulating layer 131 are provided at regular intervals along one direction of the display region 103.

Next, as illustrated in FIG. 5D, the organic insulating layer 132 is formed over the inorganic insulating layer 131. The organic insulating layer 132 can be formed using, for example, an acrylic resin, an epoxy resin, a polyimide resin, a silicone resin, a fluorine resin, a siloxane resin, or the like by an inkjet method, an organic vapor deposition method, a slit coater, or the like. The organic insulating layer 132 preferably has a water vapor transmission rate of 1 × 10 ⁰ to 1 × 10 ⁻⁵ (g / m ² / day (40 ° C. 90% RH)). The thickness of the organic insulating layer 132 is preferably 5 μm or more and 15 μm or less.

Next, as illustrated in FIG. 5E, the inorganic insulating layer 133 is formed over the organic insulating layer 132. The inorganic insulating layer 133 can be formed using a material similar to that of the inorganic insulating layer 131. As the inorganic insulating layer 133, a film having a moisture permeability of 1 × 10 ⁻⁵ (g / m ² / day (40 ° C. 90% RH)) or less is preferably used. The thickness of the inorganic insulating layer 133 is preferably 500 nm to 1000 nm.

  Next, as illustrated in FIG. 5F, a thin region 152 is formed in the inorganic insulating layer 133. Similar to the region 151 formed in the inorganic insulating layer 131, the region 152 can be formed by irradiation with ultraviolet laser light, dry etching using a mask, or notching with a microprobe. The thin regions 152 provided in the inorganic insulating layer 133 are provided at regular intervals along one direction of the display region 103. The region 152 preferably does not overlap with the region 151 provided in the inorganic insulating layer 131.

  Lastly, the display device 100 illustrated in FIG. 2 can be formed by attaching the counter substrate 102 to the inorganic insulating layer 133 with an adhesive (not shown) interposed therebetween.

  As described above, in the display device 100 according to the present embodiment, a thin region is formed in the inorganic insulating layer in order to control the location where the inorganic insulating layer breaks in advance. As shown in FIG. 4, even if the inorganic insulating layer has cracks, the distance until moisture and oxygen reach the light emitting element can be made sufficiently long compared to the case where cracks occur randomly. it can. Thereby, since the time until the light emitting element is deteriorated can be lengthened, the reliability of the display device 100 can be improved.

  Next, a thin region formed in the inorganic insulating layer will be described with reference to FIGS. 6A to 6C. 6C, the shape of the concave portion formed in the inorganic insulating layer 131 is described, but the same applies to the shape of the concave portion formed in the inorganic insulating layer 133. 6 to 6C are cross-sectional views taken along the line A1-A2 of the display device 100 shown in FIG.

  FIG. 6A shows a cross-sectional shape of the thin region 151 a formed in the inorganic insulating layer 131. The thin region 151a has a substantially triangular shape when the display device is viewed in cross section. Since the thin region 151a has a substantially triangular shape, stress is easily applied, so that cracks can be easily generated in the region 151a.

  FIG. 6B shows a cross-sectional shape of the thin region 151 b formed in the inorganic insulating layer 131. The thin region 151b has a substantially rectangular shape when the display device is viewed in cross section. Note that the square corners may be rounded.

  FIG. 6C shows a cross-sectional shape of a region 151c with a small film thickness formed in the inorganic insulating layer 131. The thin region 151c has a rounded shape when the display region is viewed in cross section.

  As shown in FIGS. 6A to 6C, the shape of the thin region 151 when viewed in cross section can be various shapes. The shape of the region 151 formed in the inorganic insulating layer 131 and the region 152 formed in the inorganic insulating layer 133 in cross-sectional view is to control the location of cracks generated in the inorganic insulating layer when the display device is repeatedly bent. Any shape can be used.

(Second Embodiment)
In this embodiment, a display device that is partly different from the display device described in the first embodiment will be described with reference to FIGS.

  In the display device illustrated in FIGS. 7 and 8, the arrangement of the thin region 151 provided in the inorganic insulating layer 131 and the thin region 152 provided in the inorganic insulating layer 133 is the same as that of the display device illustrated in FIG. Is different. Since other configurations are the same as the configurations described in the first embodiment, detailed description thereof is omitted.

  FIG. 7 illustrates an example in which a thin region 151 provided in the inorganic insulating layer 131 and a thin region 152 provided in the inorganic insulating layer 133 are provided to intersect each other. The thin region 151 provided in the inorganic insulating layer 131 is provided at a constant interval m along the x direction. In addition, the thin region 152 provided in the inorganic insulating layer 133 is provided at a constant interval n along the y direction intersecting the x direction. Although FIG. 4 shows a case where the length of the interval m is different from the length of the interval n, the present invention is not limited to this. The length of the interval m and the length of the interval n may be the same.

  Note that although FIG. 7 illustrates an example in which the region 151 is provided in the x direction and the region 152 is provided in the y direction, the present invention is not limited to this. The region 151 may be provided in the y direction, and the region 152 may be provided in the x direction. Although not illustrated, the region 151 has a recess when viewed in cross-section, and the region 152 has a recess.

  Next, FIG. 8 illustrates an example in which the thin region 151 provided in the inorganic insulating layer 131 and the thin region 152 provided in the inorganic insulating layer 133 are provided in a honeycomb shape. As shown in FIG. 8, it is preferable that the honeycomb shape of the region 151 and the honeycomb shape of the region 152 do not overlap when the display device is viewed in plan. 8 shows an example in which the hexagonal size of the region 151 and the hexagonal size of the region 152 are the same, the present invention is not limited to this, and the hexagonal shape of the region 151 is shown. And the hexagonal size of the region 152 may be different. Although not illustrated, the region 151 has a recess when viewed in cross-section, and the region 152 has a recess. 6A to 6C can be referred to for the shape of the recess.

  As shown in FIGS. 7 and 8, a region 151 having a small thickness provided in the inorganic insulating layer 131 and a region 152 having a small thickness provided in the inorganic insulating layer 133 may overlap. However, it is preferable to reduce a region where the region 151 and the region 152 overlap in order to suppress a moisture or oxygen intrusion path when a crack is generated by repeatedly bending the display device.

  Next, FIG. 9 illustrates an example in which the sealing film 140 is formed by alternately stacking three inorganic insulating layers and two organic insulating layers in the display device.

  As shown in FIG. 9, the display device further includes an organic insulating layer 134 on the inorganic insulating layer 133, and further includes an inorganic insulating layer 136. In addition, in the inorganic insulating layer 136, the thin region 153 is provided at a constant interval o along one direction of the display region. The thin region 153 does not overlap with the region 152 provided in the inorganic insulating layer 133. Further, the thin region 153 may overlap with the region 151 provided in the inorganic insulating layer 131. In the figure, the interval m in which the thin region 151 is provided and the interval o in which the thin region 153 is provided have the same length, but the interval m and the interval o are different. It may be.

  By providing the organic insulating layer 134 and the inorganic insulating layer 136, the intrusion route of moisture and oxygen can be further increased. Thereby, the distance until moisture and oxygen reach the light emitting element can be sufficiently increased. Thereby, since the time until the light emitting element is deteriorated can be lengthened, the reliability of the display device 100 can be improved.

  Note that the number of organic insulating layers and inorganic insulating layers used as the sealing film 140 is preferable because the intrusion path of moisture and oxygen becomes longer as the number increases. However, as the number of layers increases, the radius of curvature at which the display device is bent increases. Therefore, it may be set as appropriate according to the radius of curvature at which the display device is bent.

(Third embodiment)
In the present embodiment, a display device that is partially different from the display devices according to the first and second embodiments will be described with reference to FIGS. 10 to 12D.

[Configuration of display device]
In the display device illustrated in FIG. 10, the inorganic insulating layer 131 is not provided with a thin region, and the organic insulating layer 132 is provided with a convex portion 137. The inorganic insulating layer 133 provided on the organic insulating layer 132 is provided with a thin region 154, and the thin region 154 is provided in contact with the corner portion 138 of the convex portion 137.

  The convex portions 137 provided in the organic insulating layer 132 are provided at a constant interval q along one direction of the display region 103. Further, the width p of the convex portion 137 is shorter than the constant interval q.

  An inorganic insulating layer 133 is provided on the organic insulating layer 132. A thin region 154 is provided in the inorganic insulating layer 133 provided in contact with the corner 138 of the convex portion 137 of the organic insulating layer 132.

  Also in the display device illustrated in FIG. 10, when the region 154 in which the inorganic insulating layer 133 is thin is provided, if stress is applied to the sealing film 140 due to bending of the display device, cracks are likely to occur in the region 154. Accordingly, when the display device is repeatedly bent, cracks are likely to occur in the region 154. By providing a location where a crack is generated in the sealing film 140 in advance, intrusion of moisture and oxygen can be suppressed as compared with a case where the sealing film 140 is randomly cracked.

  In addition, as illustrated in FIG. 11, thin regions 151 may be provided in the inorganic insulating layer 131 along the display region 103 in one direction at regular intervals. It is preferable that the region 151 provided in the inorganic insulating layer 131 and the region 154 provided in the inorganic insulating layer 133 do not overlap with each other. The region 151 is preferably provided between adjacent regions 154 provided in the inorganic insulating layer 133. Accordingly, even when a crack is generated in the sealing film 140 when the display device is bent, the distance until moisture or oxygen reaches the light emitting element is sufficiently long. Accordingly, the time until the light-emitting element is deteriorated by moisture or oxygen can be extended, so that the reliability of the display device can be improved.

  As described above, in the display device according to the present embodiment, the path through which moisture and oxygen enter is controlled by controlling the location where the inorganic insulating layer breaks in the sealing film 140 in advance. Even if the inorganic insulating layer has cracks, the distance until moisture and oxygen reach the light-emitting element can be sufficiently increased as compared with the case where cracks occur randomly. Thereby, since the time until the light emitting element is deteriorated can be lengthened, the reliability of the display device 100 can be improved.

[Manufacturing method of display device]
Next, a method for manufacturing the display device according to the present embodiment will be described with reference to FIGS. 12A to 12D. Note that description of steps similar to those in FIGS. 5A to 5F is omitted as appropriate.

  As illustrated in FIG. 12A, the element formation layer 160 is formed over the substrate 101. Next, the inorganic insulating layer 131 is formed over the element formation layer 160. 5A and 5B can be referred to for the formation method of the element formation layer 160 and the inorganic insulating layer 131.

  Next, the organic insulating layer 132 is formed over the inorganic insulating layer 131. For a method for forming the organic insulating layer 132, FIG. 5D can be referred to.

  As shown in FIG. 12B, a convex portion 137 is formed on the organic insulating layer 132. The convex portions 137 are formed at regular intervals along one direction of the display region 103. The convex portion 137 formed on the organic insulating layer 132 can be formed by a photolithography method.

  Next, as illustrated in FIG. 12C, the inorganic insulating layer 133 is formed over the organic insulating layer 132. When the inorganic insulating layer 133 is formed using a sputtering method or a CVD method, a film is likely to be formed on a flat surface, whereas a film is hardly formed on the corner portion 138 of the convex portion 137. By utilizing the tendency that a film is hardly formed at the corner portion 138 of the convex portion 137, the region 154 having a smaller film thickness than the flat region is formed.

  Lastly, the display device illustrated in FIG. 10 can be formed by bonding the counter substrate 102 to the inorganic insulating layer 133 with an adhesive (not illustrated) interposed therebetween.

  As described above, the display device according to the present invention can form the thin region 154 in the inorganic insulating layer 133 in addition to the method of performing notching or etching with a microprobe. By providing the region 154, when stress is applied to the sealing film 140 due to bending of the display device, a crack is easily generated in the region 154. Accordingly, when the display device is repeatedly bent, cracks are likely to occur in the region 154. By providing a location where a crack is generated in the sealing film 140 in advance, intrusion of moisture and oxygen can be suppressed as compared with a case where the sealing film 140 is randomly cracked.

(Fourth embodiment)
In the present embodiment, a display device that is partially different from the display devices according to the first to third embodiments will be described with reference to FIGS. 13 to 16.

  In the display device according to the first to third embodiments, the configuration in which the path through which moisture and oxygen enter is controlled by controlling the location where the inorganic insulating layer breaks in advance in the sealing film 140 has been described. In this embodiment, a configuration in which an organic insulating layer included in the sealing film 140 is divided into a plurality of regions and a partition wall 156 formed of an inorganic insulating layer 133 is provided between adjacent organic insulating layers will be described.

  FIG. 13 shows an enlarged plan view of a part of the display area 103 of the display device according to the present embodiment. FIG. 13 shows a partition wall 156 formed of an inorganic insulating layer 133 provided between the organic insulating layers 132a and 132b divided into a plurality of regions. Note that although the inorganic insulating layer 133 is actually provided on the entire surface, in order to illustrate the partition wall 156, the inorganic insulating layer 133 is not illustrated in FIG. 13 in a region overlapping with the organic insulating layers 132a and 132b and the like. ing.

  One of the organic insulating layers divided into a plurality of regions is provided so as to overlap with the plurality of pixels 109. For example, as shown in FIG. 13, the organic insulating layer 132a is provided so as to overlap with nine pixels 109, which are three pixels in the x direction and three pixels in the y direction. Although FIG. 13 illustrates a structure in which the organic insulating layer 132a overlaps with nine pixels, the present invention is not limited to this. The number of pixels overlapping with the divided organic insulating layer 132a can be set as appropriate.

  In addition, a partition 156 is provided between adjacent organic insulating layers (for example, the organic insulating layers 132a and 132b). The partition wall 156 is formed of an inorganic insulating layer 133. The inorganic insulating layer 133 has a function of suppressing permeation of moisture and oxygen. Therefore, even if moisture or oxygen enters the organic insulating layer 132a, movement of moisture or oxygen to the organic insulating layer 132b can be suppressed. That is, by providing the partition wall 156, it is possible to suppress moisture and oxygen from moving in the horizontal direction with respect to the display region 103.

  A partition 156 provided between adjacent organic insulating layers is preferably not overlapped with the pixel 109. Since the partition 156 and the pixel 109 do not overlap with each other, a decrease in luminance due to the partition 156 can be prevented.

  As shown in FIG. 13, a thin region 151 provided in the inorganic insulating layer 131 is provided along one direction of the display region 103. A thin region 152 provided in the inorganic insulating layer 133 is provided along one direction of the display region 103. Further, the region 151 and the region 152 are provided so as not to overlap with the partition wall 156 in one direction. The region 151 and the region 152 may have a region intersecting with the partition wall.

  FIG. 14 is a cross-sectional view taken along line C1-C2 of the display device shown in FIG. In the display device illustrated in FIG. 14, an element formation layer 160 is provided over a substrate 101. A sealing film 140 is provided on the element formation layer 160. The sealing film 140 shown in FIG. 14 is the same as the other embodiments in that it includes an inorganic insulating layer 131, an organic insulating layer 132, and an inorganic insulating layer 133.

  As shown in FIG. 14, the inorganic insulating layer 131 is provided with a plurality of thin regions 151 along the first direction (x direction). In addition, the inorganic insulating layer 131 is provided with a thin region 151 at a constant interval m in a second direction (y direction) intersecting the first direction. Although not shown in FIG. 14, the inorganic insulating layer 133 is provided with thin regions 152 at a constant interval n in the second direction as in FIG. 9.

  As shown in FIG. 14, the organic insulating layer 132 is divided into a plurality of regions. The inorganic insulating layer 133 is in contact with the inorganic insulating layer 131 between the adjacent organic insulating layers 132a and 132b. The inorganic insulating layer 133 provided between the adjacent organic insulating layers 132 a and 132 b functions as the partition wall 156. Each of the divided organic insulating layers 132 a and 132 b is sealed with an inorganic insulating layer 131 and an inorganic insulating layer 133.

  The width r of the divided organic insulating layer 132 in the second direction (y direction in FIG. 13) is preferably smaller than the interval m between the regions 151 where the inorganic insulating layer 131 is thin. The width r of the divided organic insulating layer 132 in the second direction is preferably smaller than the interval n between the regions 152 where the inorganic insulating layer 133 is thin. In addition, at least one partition wall 156 is preferably provided between the region 152 of the organic insulating layer 132 and the region 151 of the inorganic insulating layer 131. Thereby, when a crack is generated in each of the region 151 and the region 152, movement of moisture and oxygen that has entered from the crack in the region 152 can be blocked by the partition wall 156. As shown in FIG. 7, when the region 151 where the inorganic insulating layer 131 is thin is provided along the second direction, the width of the divided organic insulating layer 132 in the first direction is The distance m may be smaller than the distance m.

  FIG. 15 is a cross-sectional view when a crack is generated in the sealing film 140 of the display device. As shown in FIG. 15, a crack is generated in a region 152 where the inorganic insulating layer 133 is thin. The black circles shown in FIG. 15 indicate water, and the arrows indicate the water intrusion route. As shown in FIG. 15, it is assumed that moisture enters the organic insulating layer 132 c from a crack generated in the inorganic insulating layer 133. However, moisture that has entered the organic insulating layer 132 c can be blocked by the partition 156. In addition, the inorganic insulating layer 131 can prevent moisture from entering the element formation layer 160. That is, moisture and oxygen can be prevented from reaching the light emitting element 130. In addition, since the deterioration of the light-emitting element 130 can be suppressed, the reliability of the display device can be improved.

  Note that, as illustrated in FIG. 15, the region 151 where the inorganic insulating layer 131 is thin is surrounded by a partition wall 156 formed by the inorganic insulating layer 133. Therefore, even if a crack occurs in the region 151 where the thickness of the inorganic insulating layer 131 is thin, moisture can be blocked by the inorganic insulating layer 133, so that entry of moisture into the element formation layer 160 can be suppressed. it can.

  Next, an example in which the sealing film 140 is formed by alternately stacking three inorganic insulating layers and two organic insulating layers in the display device will be described with reference to FIGS.

  As shown in FIG. 16, in the display device, an organic insulating layer 134 is provided over the inorganic insulating layer 133, and an inorganic insulating layer 136 is provided over the organic insulating layer 134. In addition, the inorganic insulating layer 133 is provided with regions 153 having a small film thickness at a constant interval o along one direction of the display region. In FIG. 16, the interval m in which the thin film thickness region 151 is provided and the interval o in which the thin film thickness region 153 is provided are indicated by the same length, but the distance m is different from the gap o. It may be a length.

  In FIG. 16, the organic insulating layer 134 is divided into a plurality of regions. The inorganic insulating layer 135 is in contact with the inorganic insulating layer 133 between the adjacent organic insulating layers 134a and 134b. The inorganic insulating layer 135 provided between the adjacent organic insulating layers 134a and 134b functions as a partition wall 158. The divided organic insulating layers 134 a and 134 b are sealed with the inorganic insulating layer 133 and the inorganic insulating layer 135.

  The width s of the divided organic insulating layer 134 in the second direction (y direction in FIG. 16) is preferably smaller than the interval m between the regions 151 where the inorganic insulating layer 131 is thin. The width s in the second direction of the divided organic insulating layer 132 is preferably smaller than the interval n between the regions 152 where the inorganic insulating layer 133 is thin. The width s in the second direction of the divided organic insulating layer 132 is preferably smaller than the interval n between the regions 152 where the inorganic insulating layer 133 is thin. In addition, at least one partition wall 158 is preferably provided between the region 153 of the inorganic insulating layer 135 and the region 152 of the inorganic insulating layer 133. Thereby, when a crack is generated in each of the region 152 and the region 153, the movement of moisture and oxygen entering from the crack in the region 153 can be blocked by the partition wall 158.

  FIG. 16 illustrates the case where the width r in the second direction of the divided organic insulating layer 132 and the width s in the second direction of the divided organic insulating layer 134 are different from each other. And the width s may be the same. Further, the length of the width r may be longer than the length of the width s.

  When the display device is repeatedly bent, it is controlled so that a crack is generated in a thin region provided in the inorganic insulating layers 131, 133, and 135. In the case where a crack occurs in the region 153 of the inorganic insulating layer 135, moisture or oxygen enters the organic insulating layer 134. However, the organic insulating layer 134 is divided, and each of the divided organic insulating layers 134 is surrounded by a partition wall 158 made of the inorganic insulating layer 135. Therefore, even when moisture or oxygen enters the organic insulating layer 134, movement in the horizontal direction with respect to the display region 103 can be blocked by the partition 158. Further, the movement in the direction perpendicular to the display region 103 can be blocked by the inorganic insulating layer 133. Accordingly, moisture and oxygen that have entered the organic insulating layer 134 can be prevented from moving to the element formation layer 160 in which the light emitting element 130 is formed. In addition, since the deterioration of the light-emitting element 130 can be suppressed, the reliability of the display device can be improved.

  The thin region 153 provided in the inorganic insulating layer 135 may overlap with the region 152 provided in the inorganic insulating layer 133. In addition, the thin region 153 provided in the inorganic insulating layer 135 may overlap with the region 151 provided in the inorganic insulating layer 131. This is because even when cracks are generated in the thin regions 153 and 152 and moisture penetrates into the organic insulating layer 132, the inorganic insulating layer 131 can block the moisture. In addition, since the organic insulating layer 132 is surrounded by the partition 156, moisture can be prevented from passing through the partition 156 and moving to the region of the other organic insulating layer 132.

(Fifth embodiment)
In the present embodiment, the configuration of the pixel 109 in the display device 100 shown in the first embodiment will be described with reference to FIG.

  FIG. 17 is a diagram illustrating an example of the configuration of the pixel 109 in the display device 100 according to the first embodiment. Specifically, it is a diagram showing a configuration of a cross section obtained by cutting the display region 103 shown in FIG. 1 along line D1-D2. FIG. 17 shows a cross section of three light emitting elements 130 as a part of the display region 103. Note that FIG. 17 illustrates three light emitting elements 130, but actually, in the display region 103, several million or more light emitting elements are arranged in a matrix corresponding to the pixels.

  As illustrated in FIG. 17, the display device 100 includes a substrate 101, a second substrate 112, and a counter substrate 102. As the substrate 101, the second substrate 112, and the counter substrate 102, a glass substrate, a quartz substrate, a flexible substrate (polyimide, polyethylene terephthalate, polyethylene naphthalate, triacetyl cellulose, cyclic olefin copolymer, cycloolefin polymer, other flexibility) (Resin substrate) can be used. In the case where the substrate 101, the second substrate 112, and the counter substrate 102 do not need to have a light-transmitting property, a metal substrate, a ceramic substrate, or a semiconductor substrate can be used. By using flexible substrates as the substrate 101, the second substrate 112, and the counter substrate 102, a bendable display device can be obtained.

  A base film 113 is provided on the substrate 101. The base film 113 is an insulating layer made of an inorganic material such as silicon oxide, silicon nitride, or aluminum oxide. The base film 113 is not limited to a single layer, and may have, for example, a stacked structure in which a silicon oxide layer and a silicon nitride layer are combined. This configuration may be determined as appropriate in consideration of adhesion to the substrate 101 and gas barrier properties with respect to a transistor 120 described later.

  A transistor 120 is provided over the base film 113. The structure of the transistor 120 may be a top gate type or a bottom gate type. In this embodiment, the transistor 120 includes a semiconductor layer 114 provided on the base film 113, a gate insulating film 115 covering the semiconductor layer 114, and a gate electrode 116 provided on the gate insulating film 115. Further, over the transistor 120, a source or drain electrode 117 and a source or drain electrode 118 which are provided over the interlayer insulating film 122 and the interlayer insulating film 122 covering the gate electrode 116 and connected to the semiconductor layer 114 are provided. It has been. In this embodiment, an example in which the interlayer insulating film 122 has a single layer structure has been described, but the interlayer insulating film 122 may have a laminated structure.

  Note that the material of each layer included in the transistor 120 may be a known material and is not particularly limited. For example, as the semiconductor layer 114, polysilicon, amorphous silicon, or an oxide semiconductor can be generally used. As the gate insulating film 115, silicon oxide or silicon nitride can be used. The gate electrode 116 is made of a metal material such as copper, molybdenum, tantalum, tungsten, or aluminum. As the interlayer insulating film 122, silicon oxide or silicon nitride can be used. The source or drain electrode 117 and the source or drain electrode 118 are each made of a metal material such as copper, titanium, molybdenum, or aluminum.

  Although not shown in FIG. 17, a first wiring made of the same metal material as that of the gate electrode 116 can be provided in the same layer as the gate electrode 116. The first wiring can be provided as a scanning line driven by the scanning line driving circuit 104, for example. Although not illustrated in FIG. 17, a second wiring extending in a direction intersecting with the first wiring can be provided in the same layer as the source or drain electrode 117 and the source or drain electrode 118. The second wiring can be provided as a data line driven by the signal line driver circuit 105, for example.

  A planarization film 123 is provided over the transistor 120. The planarizing film 123 includes an organic resin material. As the organic resin material, for example, a known organic resin material such as polyimide, polyamide, acrylic, or epoxy can be used. These materials have a feature that a film can be formed by a solution coating method and a flattening effect is high. Although not particularly illustrated, the planarization film 123 is not limited to a single layer structure, and may have a stacked structure of a layer containing an organic resin material and an inorganic insulating layer.

  The planarization film 123 has a contact hole that exposes a part of the source or drain electrode 118. The contact hole is an opening for electrically connecting a pixel electrode 125 and a source or drain electrode 118 described later. Therefore, the contact hole is provided so as to overlap with part of the source or drain electrode 118. At the bottom surface of the contact hole, the source or drain electrode 118 is exposed.

  A protective film 124 is provided on the planarizing film 123. The protective film 124 overlaps with the contact hole formed in the planarizing film 123. The protective film 124 preferably has a barrier function against moisture and oxygen. For example, the protective film 124 is formed using an inorganic insulating material such as a silicon nitride film or aluminum oxide.

  A pixel electrode 125 is provided on the protective film 124. The pixel electrode 125 overlaps with the contact hole included in the planarization film 123 and the protective film 124 and is electrically connected to the source or drain electrode 118 exposed at the bottom surface of the contact hole. In the display device 100 of this embodiment, the pixel electrode 125 functions as an anode (anode) constituting the light emitting element 130. The pixel electrode 125 is configured differently depending on whether it is a top emission type or a bottom emission type. For example, in the case of a top emission type, a metal film having a high reflectance is used as the pixel electrode 125, or a work function such as an indium oxide-based transparent conductive film (for example, ITO) or a zinc oxide-based transparent conductive film (for example, IZO, ZnO) is used. A stacked structure of a high transparent conductive film and a metal film is used. Conversely, in the case of the bottom emission type, the above-described transparent conductive film is used as the pixel electrode 125. In the present embodiment, a top emission type organic EL display device will be described as an example. The end of the pixel electrode 125 is covered with an insulating layer 126 described later.

  An insulating layer 126 made of an organic resin material is provided on the pixel electrode 125. As the organic resin material, a known resin material such as polyimide, polyamide, acrylic, epoxy, or siloxane can be used. The insulating layer 126 has an opening in part over the pixel electrode 125. The insulating layer 126 is provided between pixel electrodes 125 adjacent to each other so as to cover an end portion (edge portion) of the pixel electrode 125, and functions as a member that separates the adjacent pixel electrodes 125. For this reason, the insulating layer 126 is generally also called a “partition wall” or a “bank”. A part of the pixel electrode 125 exposed from the insulating layer 126 becomes a light emitting region of the light emitting element 130. It is preferable that the opening of the insulating layer 126 has a tapered inner wall. Accordingly, it is possible to reduce a coverage defect at the end of the pixel electrode 125 when a light emitting layer described later is formed. The insulating layer 126 may not only cover the end portion of the pixel electrode 125 but also function as a filler that fills a recess caused by the contact hole of the planarization film 123 and the protective film 124.

  An organic layer 127 made of an organic material is provided on the pixel electrode 125. The organic layer 127 has a light emitting layer made of at least an organic material and functions as a light emitting portion of the light emitting element 130. In addition to the light emitting layer, the organic layer 127 can also include various charge transport layers such as an electron injection layer, an electron transport layer, a hole injection layer, and a hole transport layer. The organic layer 127 is provided to cover the light emitting region, that is, to cover the opening of the insulating layer 126 and the opening of the insulating layer 126 in the light emitting region.

  In the present embodiment, a configuration in which each color of RGB is displayed by providing a light emitting layer that emits light of a desired color in the organic layer 127 and forming the organic layer 127 having a different light emitting layer on each pixel electrode 125. And That is, in the present embodiment, the organic layer 127 is discontinuous between the adjacent pixel electrodes 125. Various charge transport layers are continuous between adjacent pixel electrodes 125. A known structure or a known material can be used for the organic layer 127, and the organic layer 127 is not particularly limited to the configuration of this embodiment. The organic layer 127 may include a light emitting layer that emits white light, and may display each color of RGB through a color filter. In this case, the organic layer 127 may also be provided on the insulating layer 126.

  A counter electrode 128 is provided on the organic layer 127 and the insulating layer 126. The counter electrode 128 functions as a cathode constituting the light emitting element 130. Since the display device 100 of this embodiment is a top emission type, a transparent electrode is used as the counter electrode 128. As the thin film constituting the transparent electrode, an MgAg thin film or a transparent conductive film (ITO or IZO) is used. The counter electrode 128 is also provided on the insulating layer 126 across the pixels 109. The counter electrode 128 is electrically connected to an external terminal through a lower conductive layer in a peripheral region near the end of the display region 103. As described above, in this embodiment, a part of the pixel electrode 125 exposed from the insulating layer 126 (anode), the organic layer 127 (light emitting unit), and the counter electrode 128 (cathode) constitute the light emitting element 130.

  In this specification and the like, the element formation layer 160 is formed from the semiconductor layer 114 to the counter electrode 128. Note that the element formation layer 160 may include a base film.

  A sealing film 140 is preferably provided over the display region 103. The sealing film 140 is provided to prevent water and oxygen from entering. The sealing film 140 can be provided with a combination of an inorganic insulating material and an organic insulating material. FIG. 17 shows an example in which an inorganic insulating layer 131, an organic insulating layer 132, and an inorganic insulating layer 133 are provided as the sealing film 140. By providing the sealing film over the display region 103, it is possible to prevent water and oxygen from entering the light-emitting element 130.

As the inorganic insulating layer 131 and the inorganic insulating layer 133, for example, a silicon nitride (Si _x N _y ), a silicon oxynitride (SiO _x N _y ), a silicon nitride oxide (SiN _x O _y ), an oxide is formed by a CVD method or a sputtering method. It is formed using a film of aluminum (Al _x O _y ), aluminum nitride (Al _x N _y ), aluminum oxynitride (Al _x O _y N _z ), aluminum nitride oxide (Al _x N _y O _z ), or the like. (X, y, and z are arbitrary). The thickness of the inorganic insulating layer 131 is preferably 500 nm to 1000 nm, and the thickness of the inorganic insulating layer 133 is preferably 500 nm to 1000 nm. By providing the inorganic insulating layer 131 and the inorganic insulating layer 133 with the above thicknesses, water and oxygen can be prevented from entering the light-emitting element 130. As the organic insulating layer 132, for example, an acrylic resin, an epoxy resin, a polyimide resin, a silicone resin, a fluorine resin, a siloxane resin, or the like can be used as the organic insulating layer 132. The thickness of the organic insulating layer 132 is preferably 5 μm or more and 15 μm or less.

  Note that the inorganic insulating layer 131 and the inorganic insulating layer 133 are provided with the thin regions described in the previous embodiment, respectively, but are not illustrated in FIG.

  A filler 139 is provided over the inorganic insulating layer 133. As the filler 139, for example, an acrylic, rubber, silicone, or urethane adhesive can be used. In addition, the filler 139 may be provided with a spacer in order to secure a gap between the substrate 101 and the counter substrate 102. Such a spacer may be mixed with the filler 139 or may be formed on the substrate 101 with a resin or the like.

  The counter substrate 102 may be provided with, for example, an overcoat layer for planarization. When the organic layer 127 emits white light, the counter substrate 102 is provided with a color filter corresponding to each color of RGB on the main surface (surface facing the substrate 101) and a black matrix provided between the color filters. It may be done. In the case where a color filter is not formed on the counter substrate 102 side, for example, a color filter may be formed directly on the inorganic insulating layer 133 and the filler 139 may be formed thereon. Note that the organic insulating layer 132 has a planarizing action, and each layer above the organic insulating layer 132 is formed flat. Therefore, the organic insulating layer 132 is thick on the light emitting element 130 and thin on the insulating layer 126.

  As described above, a sealing film is required to protect the light emitting element 130 from water and oxygen. However, when the display device is used as a foldable display device, the inorganic insulating layer functioning as the sealing film 140 may be broken by bending the display device. When the inorganic insulating layer is broken, water, oxygen, or the like enters from the outside, and the light emitting element 130 is deteriorated. In addition, the reliability of the display device may be reduced due to deterioration of the light emitting element 130.

  As described above, in the display device 100 according to the present embodiment, a thin region is formed in the inorganic insulating layer in order to control the location where the inorganic insulating layer breaks in advance. Even if the inorganic insulating layer cracks, the distance until moisture and oxygen reach the light-emitting element 130 can be sufficiently increased as compared with the case where cracks occur randomly. Thereby, since the time until the light emitting element 130 is deteriorated can be lengthened, the reliability of the display device 100 can be improved.

  An embodiment of a display device according to the present invention will be described. In this embodiment, the number of inorganic insulating layers and organic insulating layers necessary as a sealing film and the interval at which the thin region of the inorganic insulating layer is provided will be described in detail.

  Table 1 shows the WVTR of the inorganic insulating layer, the WVTR of the organic insulating layer, and the radius of curvature for bending the display device used in the description of this example.

In the case of the above conditions, the path X (μm) through which moisture and oxygen enter in the organic insulating layer can be calculated as follows. Here, 1 × 10 ⁻⁵ is a WVTR required as a sealing film, X is a film thickness of the organic insulating layer, and 1 × 10 ⁰ is a WVTR of the organic insulating layer.
1 × 10 ⁻⁵ = X × 1 × 10 ⁰
X = 100000 μm

Further, the area where the stress is applied by bending the display device can be calculated as follows.
25 × π ≒ 79mm

Accordingly, thin regions are formed at intervals of 78 mm in each inorganic insulating layer in order to relieve stress. In addition, a path of 78/2 = 39 mm can be secured per organic insulating layer. Therefore, since the number of necessary organic insulating layers only needs to exceed X = 1000000 μm, it is obtained as follows.
39 × 3 = 117mm> X

Therefore, three layers of organic insulating layers are required as the sealing film, and four layers of inorganic insulating layers are required. As the sealing film, four inorganic insulating layers and three organic insulating layers are alternately provided to obtain WVTR = 1 × 10 ^{−5 and} can withstand the bending stress of the display device. it can.

100: display device, 101: substrate, 102: counter substrate, 103: display area, 104: scanning line driving circuit, 105: signal line driving circuit, 107: terminal, 108: flexible printed circuit board, 109: pixel, 110: peripheral Region: 112: second substrate, 113: base film, 114: semiconductor layer, 115: gate insulating film, 116: gate electrode, 117: source electrode or drain electrode, 118: source electrode or drain electrode, 120: transistor, 122 : Interlayer insulating film, 123: planarizing film, 124: protective film, 125: pixel electrode, 126: insulating layer, 127: organic layer, 128: counter electrode, 130: light emitting element, 131: inorganic insulating layer, 132: organic Insulating layer, 132a: Organic insulating layer, 132b: Organic insulating layer, 132c: Organic insulating layer, 133: Inorganic insulating layer, 134: Organic insulating 134a: organic insulating layer, 134b: organic insulating layer, 135: inorganic insulating layer, 136: inorganic insulating layer, 137: convex portion, 138: corner portion, 139: filler, 140: sealing film, 151: region, 151a: region, 151b: region, 151c: region, 152: region, 153: region, 154: region, 156: partition, 158: partition, 160: element formation layer

Claims (13)

A display area provided on the substrate;
A first inorganic insulating layer provided on the display region;
A first organic insulating layer provided on the first inorganic insulating layer;
A second inorganic insulating layer provided on the first organic insulating layer,
The first inorganic insulating layer has a first region and a second region having a thickness smaller than that of the first region,
The second inorganic insulating layer has a third region and a fourth region having a thickness smaller than that of the third region,
The second region is disposed along a first direction;
The fourth region is disposed along the first direction;
The display device, wherein the second region does not overlap the fourth region. The second region is a recess;
The display device according to claim 1, wherein the fourth region is a recess. The display device according to claim 1, wherein the first inorganic insulating layer and the second inorganic insulating layer have a water vapor transmission rate of 1 × 10 ⁻⁵ (g / m ² / day) or less. The first organic insulating layer is divided into a plurality of regions,
The first organic insulating layers divided into the plurality of regions are provided separately from each other,
2. The display device according to claim 1, wherein the second inorganic insulating layer covers the first organic insulating layer divided into the plurality of regions, and is provided between the divided first organic insulating layers adjacent to each other. . A second organic insulating layer provided on the second inorganic insulating layer;
A third inorganic insulating layer provided on the second organic insulating layer,
The display device according to claim 1, wherein the third inorganic insulating layer includes a fifth region and a sixth region having a thickness smaller than that of the fifth region.   The display device according to claim 5, wherein the fifth region is disposed along the first direction and overlaps the second region. The second organic insulating layer is divided into a plurality of regions,
The second organic insulating layers divided into the plurality of regions are provided separately from each other,
The display device according to claim 5, wherein the third inorganic insulating layer covers the second organic insulating layer divided into the plurality of regions, and is provided between the divided second organic insulating layers adjacent to each other. . A display area provided on the substrate;
A first inorganic insulating layer provided on the display region;
A first organic insulating layer provided on the first inorganic insulating layer;
A second inorganic insulating layer provided on the first organic insulating layer,
The first inorganic insulating layer has a first region and a second region having a thickness smaller than that of the first region,
The second inorganic insulating layer has a third region and a fourth region having a thickness smaller than that of the third region,
The second region is disposed along a first direction;
The display device, wherein the fourth region is disposed along a second direction that intersects the first direction. The second region is a recess;
The display device according to claim 8, wherein the fourth region is a recess. The display device according to claim 8, wherein the first inorganic insulating layer and the second inorganic insulating layer have a water vapor transmission rate of 1 × 10 ⁻⁵ (g / m ² / day) or less. A display area provided on the substrate;
A first inorganic insulating layer provided on the display region;
A first organic insulating layer provided on the first inorganic insulating layer;
A second inorganic insulating layer provided on the first organic insulating layer,
The first organic insulating layer has convex portions at a first interval along a first direction;
The second inorganic insulating layer has a first region and a second region having a thickness smaller than that of the first region,
The display device, wherein the second region is provided in contact with a corner of the convex portion. The display device according to claim 11, wherein the first inorganic insulating layer and the second inorganic insulating layer have a water vapor transmission rate of 1 × 10 ⁻⁵ (g / m ² / day) or less. The first inorganic insulating layer has a third region and a fourth region having a thickness smaller than that of the third region,
The fourth region is disposed along the first direction;
The display device according to claim 11, wherein the fourth region does not overlap the second region.

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