Light-emitting device, display device, imaging device, and electronic device

Abstract

To provide a device having improved moisture resistance.SOLUTION: The present invention provides a light-emitting device including, on a substrate, an element area in which a light-emitting element is disposed, and a terminal area in which a terminal portion electrically connected to the light-emitting element is disposed. The light-emitting element includes, sequentially from the substrate, a reflective layer, a first insulating layer, a first electrode, a second insulating layer, an organic layer that includes a light-emitting layer, a second electrode, and a third insulating layer. The terminal portion includes a pad electrode of a material identical to that of the reflective layer. The pad electrode includes an exposed portion at which a surface on a far side from the substrate is exposed. The third insulating layer extends from the element area up to an edge of the exposed portion in the terminal area.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a light-emitting device, a display device, an imaging device, and an electronic apparatus.

Background Art

[0002] In recent years, organic electronic devices using organic compounds have been studied. In particular, organic light-emitting devices, also called organic electroluminescence devices or organic EL devices, have been rapidly developed.

[0003] For full-colorization in a display device, it is necessary to obtain light of three primary colors: red (R), green (G), and blue (B). When an organic light-emitting device is used as a light source, as methods for obtaining RGB three primary colors, there are known methods such as separately coating each light-emitting layer so as to emit red, green, and blue light, or a method of separating colors using a white light-emitting device and an RGB color filter. However, in a light-emitting device using an organic light-emitting material, since light having a wide spectrum peculiar to the organic material is emitted, it is difficult to obtain light with high color purity, and the color gamut (color reproduction range) of the obtained light becomes narrow. Therefore, conventionally, a method of improving the color purity of light by providing an interference structure and using a micro resonator effect has been proposed. For example, Patent Document 1 discloses a display device having an interference structure in each pixel.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In Patent Document 1, a connection portion for external connection is configured by laminating a reflective conductive material, a contact electrode, and a transparent electrode. By the way, organic compounds of light-emitting materials used in organic EL elements generally have low moisture resistance, and it is known that dark spots and leakage currents are caused by moisture invading from the outside. Therefore, it is preferable that a sealing structure capable of suppressing the invasion of moisture is formed on the display device. However, in the connection portion having a conventional configuration, there has been a problem that the sealing performance deteriorates because the transparent electrode serves as a moisture invasion path or the like.

[0006] An object of the present invention is to provide a device with improved moisture resistance.

Means for Solving the Problems

[0007] A first aspect of the present invention has, on a substrate, an element region in which a light-emitting element is disposed and a terminal region in which a terminal portion electrically connected to the light-emitting element is disposed. The light-emitting element includes, in order from the substrate side, a reflective layer, a first insulating layer, a first electrode, a second insulating layer, an organic layer including a light-emitting layer, a second electrode, and a third insulating layer. The terminal portion has a pad electrode made of the same material as the reflective layer. The pad electrode has an exposed portion where the surface on the side far from the substrate is exposed. The third insulating layer extends from the element region to the edge of the exposed portion in the terminal region. A light-emitting device is provided.

[0008] A second aspect of the present invention has, on a substrate, an element region in which a light-emitting element is disposed and a terminal region in which a terminal portion electrically connected to the light-emitting element is disposed. The light-emitting element includes, in order from the substrate side, a reflective layer, a first insulating layer, a first electrode, a second insulating layer, an organic layer including a light-emitting layer, a second electrode, and a third insulating layer. The terminal portion has a pad electrode made of the same material as the reflective layer. The pad electrode has an exposed portion where the surface on the side far from the substrate is exposed. A light-emitting device is provided, wherein in at least a part of the pad electrode, the total layer thickness of the first insulating layer and the second insulating layer is smaller than the total layer thickness of the first insulating layer and the second insulating layer on the reflective layer.

[0009] A third aspect of the present invention provides a display device including a display unit having the above-described light-emitting device and a control circuit that controls the display unit. A fourth aspect of the present invention provides a photoelectric conversion device including an optical unit, an imaging element that receives light that has passed through the optical unit, and a display unit that displays an image captured by the imaging element, wherein the display unit has the above-described light-emitting device. A fifth aspect of the present invention provides an electronic device including a display unit having the above-described light-emitting device, a housing in which the display unit is provided, and a communication unit that is provided in the housing and communicates with the outside.

Effects of the Invention

[0010] According to the present invention, it is possible to provide a device with improved moisture resistance.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

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Figure 12

Embodiments for Carrying Out the Invention

[0012] <Embodiment 1> Embodiment 1 of the present invention will be described. Hereinafter, an example in which the present invention is applied to a display device will be described, but the present invention can also be applied to various devices such as a light-emitting device.

[0013] FIG. 1 is a plan view showing the structure of a display device 100 according to the present embodiment. The display device 100 has a pixel arrangement region 110 (element region) and a pad arrangement region 120 (terminal region) on a silicon substrate 200 (on the substrate). Sub-pixels 110R, 110G, and 110B for displaying red (R), green (G), and blue (B) are arranged in the pixel arrangement region 110, and light-emitting elements are arranged in each of the sub-pixels 110R, 110G, and 110B. The arrangement of each sub-pixel can be, for example, a delta type as shown in FIG. 1, but it may also be a mosaic type, a stripe type, or a Bayer type. The pad arrangement region 120 is arranged around the pixel arrangement region 110. It can also be said that the pad arrangement region 120 is arranged between the end portion of the display device 100 and the pixel arrangement region 110. A plurality of pad electrodes 121 are arranged in the pad arrangement region 120. The pad electrode 121 constitutes an external terminal portion electrically connected to the light-emitting elements arranged in each of the sub-pixels 110R, 110G, and 110B, and is connected to an external system by, for example, a flexible wiring board (not shown) and can be used as a signal processing path. As a method of connecting the pad electrode 121 to the external system, for example, a known chip-on-film (COF) can be used.

[0014] FIG. 2 shows a cross-section obtained by cutting the display device 100 along the cut line A in FIG. 1.

[0015] The sub-pixel 110G includes a driving transistor 201, wiring layers (203 to 211), and light-emitting elements (212 to 219) on a silicon substrate 200 which is a semiconductor substrate. Note that the sub-pixel 110R and the sub-pixel 110B have substantially the same structure as the sub-pixel 110G.

[0016] The driving transistor 201 includes a gate electrode and source / drain regions in the silicon substrate 200, and can control the driving of the light-emitting elements via the wiring layers. As the gate electrode, polysilicon or a metal silicide film can be used. The driving transistor 201 may be a MOS transistor at least partially formed inside the silicon substrate 200. Also, a TFT (Thin Film Transistor) can be used as the driving transistor 201.

[0017] The wiring layer is a layer including wirings and can transmit a control signal from the driving transistor 201 to the light-emitting elements. In this embodiment, the wiring layer includes an interlayer contact film 202, a contact plug 203, a first metal electrode 204, a first diffusion prevention film 205, a first inter-metal insulating film 206, a first via electrode 207, a second metal electrode 208, a second diffusion prevention film 209, a second inter-metal insulating film 210, and a second via electrode 211. For the interlayer contact film 202, the first inter-metal insulating film 206, and the second inter-metal insulating film 210, a Low-k film such as a silicon oxide film, a fluorine-doped silicon oxide film, or a carbon-doped silicon oxide film can be used. As the contact plug 203 and the second via electrode 211, for example, tungsten can be used. For the first metal electrode 204, the first via electrode 207, and the second metal electrode 208, for example, copper, aluminum, or an aluminum alloy can be used. For the first diffusion prevention film 205 and the second diffusion prevention film 209, for example, a silicon nitride film, silicon carbide, or nitrogen-doped silicon carbide can be used.

[0018] Note that the structure of the wiring layer is not particularly limited, and it can be freely designed in view of the performance and cost of the display device, etc. For example, it is also possible to omit some of the diffusion prevention films according to the constituent material of the metal electrode. Specifically, when an aluminum-copper alloy is selected for the second metal electrode 208, the second diffusion prevention film 209 may be omitted.

[0019] The light-emitting element includes, in order from the side of the silicon substrate 200 (substrate side), a reflective layer 212, an antireflection layer 213, a transparent insulating layer 214 (first insulating layer), a transparent electrode 215 (first electrode), a pixel isolation insulating layer 216 (second insulating layer), an organic layer 217, an upper electrode 218 (second electrode), and a sealing layer 219 (third insulating layer). The reflective layer 212 can be formed of a material different from that of the wiring layer (wiring), for example, an aluminum alloy or a silver alloy doped with neodymium, copper, silicon, palladium, or the like. A barrier metal (not shown) may be present below the reflective layer 212. The antireflection layer 213 is disposed on at least a part of the reflective layer 212. For the antireflection layer 213, for example, titanium or titanium nitride can be used. The transparent insulating layer 214 is disposed on the reflective layer 212 and the antireflection layer 213. For the transparent insulating layer 214, for example, a silicon oxide film, a silicon oxynitride film, a silicon nitride film, or a laminated film thereof can be used, but in this embodiment, it is assumed that the transparent insulating layer 214 contains silicon oxide. The refractive index of the transparent insulating layer 214 is preferably about 1.4 to 2.2.

[0020] The transparent electrode 215 is disposed on the transparent insulating layer 214 and functions as an anode. It is preferable to use a material having a high transmittance of light at least in the visible light region wavelength for the transparent electrode 215. As the material constituting the transparent electrode 215, transparent oxide conductive materials such as indium tin oxide (ITO), indium zinc oxide (IZO), aluminum zinc oxide (AZO), and indium gallium zinc oxide (IGZO) are preferable. Also, the refractive index of the transparent electrode 215 is preferably, for example, 1.7 or more, and particularly preferably higher than that of the transparent insulating layer 214. In other words, the refractive index of the transparent electrode 215 is the refractive index of the transparent insulating layer 214 It is preferably higher. Further, the transparent electrode 215 is preferably connected to the reflective layer 212 via the antireflection layer 213. By doing so, a lower contact resistance can be obtained than when the transparent electrode 215 is in direct contact with the reflective layer 212. The pixel isolation insulating layer 216 is disposed on the transparent electrode 215 and may have a function of separating each sub-pixel and a function of defining a light-emitting region. As the pixel isolation insulating layer 216, for example, a silicon oxide film, a silicon oxynitride film, a silicon nitride film, aluminum oxide, etc. can be used, but in this embodiment, it is assumed that the pixel isolation insulating layer 216 contains silicon oxide.

[0021] The organic layer 217 (organic compound layer) is disposed on the transparent electrode 215 and the pixel isolation insulating layer 216, and can be formed by a vapor deposition method, a spin coating method, or the like. Note that the organic layer 217 may be composed of a plurality of layers. Examples of the plurality of layers include, from the side of the transparent electrode 215, a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting layer, a hole blocking layer, an electron transport layer, and an electron injection layer. Light is emitted by recombination of holes injected from the anode side and electrons injected from the cathode side in the light-emitting layer. The light-emitting layer may be a single layer or a plurality of layers. A red light-emitting material, a green light-emitting material, or a blue light-emitting material can be used in any of the plurality of light-emitting layers, and it is also possible to obtain white light by mixing light from the plurality of light-emitting layers. Further, a light-emitting material having a complementary color relationship such as a blue light-emitting material and a yellow light-emitting material may be used in any of the plurality of light-emitting layers.

[0022] The upper electrode 218 is disposed on the organic layer 217 and functions as a cathode. The upper electrode 218 may be composed of a transparent oxide conductive material such as ITO or IZO, or may be composed of a metal thin film. When using a metal thin film, an Ag alloy thin film containing an alkaline earth metal such as magnesium (Mg) or calcium (Ca) can also be used. The upper electrode 218 can be formed, for example, by a sputtering method or a vapor deposition method.

[0023] The sealing layer 219 is disposed on the upper electrode 218 and may have a function of protecting the display device 100 from external moisture. As the sealing layer 219, for example, a silicon nitride film, a silicon oxynitride film, an aluminum oxide film, or a stacked film thereof can be used. In this embodiment, it is assumed that the sealing layer 219 contains silicon nitride. The film thickness of the sealing layer 219 is preferably, for example, 10 nm or more and 10 μm or less, and may be different between the pixel arrangement region 110 and the pad arrangement region 120. Although not shown in FIG. 2, a color filter layer, a microlens layer, or a planarization layer may be disposed on the sealing layer 219.

[0024] Here, the interference structure according to this embodiment will be described. The film thicknesses of the transparent insulating layer 214, the transparent electrode 215, and the organic layer 217 are set so that the light-emitting elements of the sub-pixels 110R, 110G, and 110B have resonance peaks at the wavelengths of red, green, and blue, respectively. For example, in the sub-pixels 110R, 110G, and 110B, the optical path length from the organic layer 217 (light-emitting layer) to the reflective layer 212 can be designed to be approximately the lengths suitable for red, green, and blue, respectively. That is, in the sub-pixels 110R, 110G, and 110B, it can be designed to satisfy the following formula (1). z = (2mπ - φa) × (λ / 4π) ··· (Formula 1) z: Optical path length from the light-emitting layer to the reflective layer 212 λ: Main wavelength of the light emitted from the light-emitting layer m: Order of interference (integer) φa: Reflection phase at the interface of the reflective layer 212 for light of the main wavelength λ

[0025] Further, when the upper electrode 218 is a highly reflective metal thin film, by designing to satisfy the following formula (2), the main wavelength of the light emitted for each sub-pixel can be enhanced. L = (2mπ - Φ) × (λ / 4π) ··· (Formula 2) L: Optical path length from the reflective layer 212 to the upper electrode 218 λ: Main wavelength of the light emitted from the light-emitting layer m: Order of interference (integer) Φ: Sum of the reflection phase at the interface of the reflective layer 212 for light of the main wavelength λ and the reflection phase at the interface of the upper electrode 218

[0026] Even when the optical path length z does not satisfy Equation 1 due to film thickness deviation in the film formation process of the organic layer 217, the transparent electrode 215, and the transparent insulating layer 214, or the influence of the light emission distribution in the light emitting layer, as long as the optical path length z is within the range from the value of Equation 1 to a value deviated by ±λ / 8, the light with wavelength λ is enhanced. Similarly, even when the optical path length L does not satisfy Equation 2, as long as the optical path length L is within the range from the value of Equation 2 to a value deviated by ±λ / 8, the light with wavelength λ is enhanced.

[0027] The peak wavelength λ can indicate a wavelength range of 420 nm to 500 nm (blue region) for the sub-pixel 110B, a wavelength range of 500 nm to 560 nm (green region) for the sub-pixel 110G, and a wavelength range of 590 nm to 680 nm (red region) for the sub-pixel 110R. When m = 0, for the sub-pixels 110B and 110G, since the blue region and the green region are close, the peak wavelength λ can also be made near the intermediate value or the same value between the blue and green regions. In this case, different emission colors of blue and green can be obtained by color separation using a spectroscopic member such as a color filter. The micro-resonator effect can be maximized when Equations 1 and 2 are satisfied simultaneously. In FIG. 2, the layer thickness T1 (film thickness) of the transparent insulating layer 214 at the portion in contact with the reflective layer 212 is preferably designed to satisfy at least one of Equations 1 and 2. Thereby, the micro-resonator effect can be maximized and the color purity of the emitted light can be enhanced. Note that the layer thickness T1 of the transparent insulating layer at the portion in contact with the reflective layer 212 and the layer thickness T3 of the transparent insulating layer at the portion in contact with the anti-reflection layer 213 may be different.

[0028] Here, the structure of the pad arrangement region 120 in FIGS. 1 and 2 will be described. The pad electrode 121 disposed in the pad arrangement region 120 is made of the same material as the reflection layer 212 disposed in the pixel arrangement region 110. In the present embodiment, as will be described later, the pad electrode 121 and the reflection layer 212 are formed by the same process. It can be said that the pad electrode 121 is in the same layer as the reflection layer 121. A planarized second intermetal insulating film 210 is disposed under the pad electrode 121 and the reflection layer 212. The pad electrode 121 and the reflection layer 212 are located at the same height when referenced to a plane parallel to the upper surface of the silicon substrate 200. In other words, the distance between the lower surface of the pad electrode 121 and the upper surface of the silicon substrate 200 is equal to the distance between the lower surface of the reflection layer 121 and the upper surface of the silicon substrate 200. The pad electrode 121 can be connected to a lower wiring layer or a transistor layer (not shown) via the second via electrode 211. The transparent insulating layer 214 and the pixel isolation insulating layer 216 extend from the pixel arrangement region 110 to above the pad electrode 121 (on the pad electrode) in the pad arrangement region 120. The pad electrode 121 has an exposed portion where the surface farther from the silicon substrate 200 is exposed, and the sealing layer 219 extends from the pixel arrangement region 110 to the edge of the exposed portion in the pad arrangement region 120. Specifically, the sealing layer 219 surrounds the edge of the exposed portion of the pad electrode 121 and is in contact with the pad electrode 121 over the entire circumference of the edge.

[0029] The effects of the present embodiment will be described. As a conventional structure, the structure shown in FIG. 3 has been proposed. In the structure of FIG. 3, a laminate of the reflection layer 212 and the transparent electrode 215 is used as the pad electrode 121. In this structure, the transparent electrode 215 exists between the sealing layer 219 and the reflection layer 212. Generally, in the transparent electrode 215, the water permeability is higher than that of the sealing layer 219 and the reflection layer 212. Therefore, in the structure of FIG. 3, as indicated by the arrow, there is a path through which moisture relatively easily enters the display device.

[0030] In the present embodiment, the material of the pad electrode 121 is the same as that of the reflection layer 212. That is, the transparent electrode 215 is not used for the pad electrode 121. For this reason, the transparent electrode 215 is exposed It does not. Further, in the present embodiment, the sealing layer 219 surrounds the edge of the exposed portion of the pad electrode 121 and is in contact with the pad electrode 121 over the entire circumference of the edge. That is, the sealing layer 219 completely covers the end of the transparent insulating layer 214 and the end of the pixel isolation insulating layer 216 on the pad electrode 121. Therefore, the transparent insulating layer 214 and the pixel isolation insulating layer 216, which generally have a higher water transmittance than the sealing layer 219 and the reflective layer 212, are not exposed either. In the present embodiment, since only the pad electrode 121 (reflective layer 212) and the sealing layer 219 with a low water transmittance are exposed, there is no water intrusion path, and it is possible to achieve high moisture resistance. Note that even if the sealing layer 219 does not surround the edge of the exposed portion of the pad electrode 121, if it extends to the edge, higher moisture resistance can be achieved compared to the case where the sealing layer 219 does not extend to the edge.

[0031] In FIG. 2, it is preferable that the insulating layer thickness T4 is designed to be smaller than the sum of the layer thickness T2 of the pixel isolation insulating layer 216 and the layer thickness T3 of the transparent insulating layer 214 at at least a part on the pad electrode 121 in the pixel arrangement region 110. The moisture resistance of the transparent insulating layer 214 and the pixel isolation insulating layer 216 can be lower than that of the sealing layer 219. By reducing the insulating layer thickness T4, the intrusion path of moisture that slightly permeates through the sealing layer 219 into the display device 100 becomes smaller, and it is possible to further improve the moisture resistance. Also, by adopting a structure in which the insulating layer thickness T4 on the end of the pad electrode 121 is small, an effect that bonding to the pad electrode 121 with a chip-on-film becomes easy can be obtained. As a result, the pitch of the pad electrodes 121 can be miniaturized, and effects such as an increase in the number of pixels and a higher functionality of the display device can also be obtained.

[0032] Also, in FIG. 2, a structure can be adopted in which the density of the pixel isolation insulating layer 216 is larger than the density of the transparent insulating layer 214. According to this structure, since the insulating layer with a large density has a relatively small water transmittance, the intrusion path of moisture that slightly permeates through the sealing layer 219 into the display device 100 becomes even smaller, and it is possible to further improve the moisture resistance.

[0033] A method for manufacturing the display device 100 will be described with reference to FIGS. 4(A) to 4(H). As shown in FIG. 4(A), a driving transistor 201 is formed on a silicon substrate 200 by combining known manufacturing techniques. After forming a contact interlayer film 202 by a method such as plasma CVD, a contact plug 203 is formed using known photolithography, etching, CVD (Chemical Vapor Deposition), CMP (Chemical Mechanical Polishing), and the like. Next, a first metal electrode 204 is formed using the copper damascene method. Next, a first diffusion prevention film 205 is formed using the plasma CVD method. Similarly, the rest of the wiring layer is formed using known techniques.

[0034] Next, as shown in FIG. 4(B), on the flattened second metal interlayer insulating film 210, a barrier metal (not shown) made of titanium or titanium nitride, a reflective layer 212, and an antireflection layer 213 are formed in this order using a method such as sputtering. At this time, the barrier metal, the reflective layer 212, and the antireflection layer 213 are formed over the entire upper surface of the second metal interlayer insulating film 210. In other words, the barrier metal, the reflective layer 212, and the antireflection layer 213 are formed over the entire surface including the pixel arrangement region 110 and the pad arrangement region 120. Next, patterning of the antireflection layer 213, the reflective layer 212, and the barrier metal is performed using known photolithography and etching techniques. At this time, the pad electrode 121 is also patterned. That is, the pad electrode 121 and the reflective layer 212 are formed in the same process and patterned in the same process.

[0035] Next, as shown in FIG. 4(C), a part of the antireflection layer 213 is removed by photolithography and etching. As the etching method, for example, RIE (Reactive Ion Etching) can be used. As the etching gas, fluorine, chlorine, or a compound thereof can be used. Thereafter, a transparent insulating layer 214 is formed by the plasma CVD method. If the film formation temperature of the transparent insulating layer 214 is high, it causes a decrease in the reflectance of the reflective layer 212 Therefore, it is preferably set in the range of, for example, 100°C to 400°C. By repeating the patterning of the antireflection layer 213 and the formation of the transparent insulating layer 214 in each of the sub-pixels 110R, 110G, and 110B, a transparent insulating layer thickness corresponding to RGB can be obtained. Next, a contact hole 401 for connecting the transparent electrode 215 and the antireflection layer 213 is opened using photolithography and etching.

[0036] Furthermore, as shown in FIG. 4(D), the transparent electrode 215 is formed by a sputtering method, and the transparent electrode 215 is patterned by photolithography and etching. Note that when etching the transparent electrode 215, the underlying transparent insulating layer 214 may also be etched. For example, when the layer thickness of the transparent insulating layer 214 is 200 nm, the transparent insulating layer 214 may be etched by RIE dry etching so that the layer thickness becomes 0 nm or more and 150 nm or less.

[0037] Next, as shown in FIG. 4(E), the pixel isolation insulating layer 216 is formed by a plasma CVD method. Note that the density of the pixel isolation insulating layer 216 can be made larger than that of the transparent insulating layer 214 by adjusting the type, flow rate, temperature, plasma power, etc. of the source gas. Furthermore, openings 402 in the pixel isolation insulating layer 216, the transparent insulating layer 214, and the antireflection layer 213 on the pad electrode 121 are provided by photolithography and etching.

[0038] Next, as shown in FIG. 4(F), an opening 403 reaching the transparent electrode 215 is formed in the pixel isolation insulating layer 216 by photolithography and etching.

[0039] Furthermore, as shown in FIG. 4(G), the organic layer 217 and the upper electrode 218 are formed by a vapor deposition method. Then, a sealing layer 219 is formed using a plasma CVD method or the like.

[0040] Next, as shown in FIG. 4(H), a pad opening 404 is formed in the sealing layer 219 on the pad electrode 121 by photolithography and etching techniques.

[0041] As described above, by the manufacturing method shown in FIGS. 4(A) to 4(H), a structure in which only the pad electrode (reflection layer 212) with a low water permeability and the sealing layer 219 are exposed can be obtained, so that high moisture resistance can be realized.

[0042] Also, according to the manufacturing method shown above, when etching the transparent electrode 215, the transparent insulating layer 214 on the pad electrode 121 can also be etched. Therefore, the thickness T4 of the insulating layer on the pad electrode 121 can be made smaller than the sum of the thickness T2 of the pixel isolation insulating layer 216 and the thickness T3 of the transparent insulating layer 214 in the pixel arrangement region 110. The moisture resistance of the transparent insulating layer 214 and the pixel isolation insulating layer 216 can be lower than that of the sealing layer 219. By reducing the insulating layer thickness T4, the intrusion path of moisture slightly permeating through the sealing layer 219 into the display device 100 becomes smaller, and the moisture resistance can be further improved.

[0043] Furthermore, according to the manufacturing method shown above, the density of the pixel isolation insulating layer 216 can be made larger than the density of the transparent insulating layer 214. By doing so, the intrusion path of moisture slightly permeating through the sealing layer 219 into the display device 100 becomes even smaller, and the moisture resistance can be further improved.

[0044] <Embodiment 2> Embodiment 2 of the present invention will be described. Note that descriptions of parts common to Embodiment 1 are omitted. FIG. 5 shows a cross-sectional structure of the display device according to this embodiment. In this embodiment, as shown in FIG. 5, in the pad arrangement region 120, the sealing layer 219 is not provided in at least a part of the portion where the exposed portion of the pad electrode 121 is present and the other portion. In other words, the sealing layer 219 is removed at least in part of the pad arrangement region 120 where the exposed portion of the pad electrode 121 is formed and at least in part of the other portions. In the present embodiment, by removing the sealing layer 219, it is possible to reduce the layer thickness of the insulating layer at the end of the pad electrode 121. As a result, bonding to the pad electrode 121 with a chip-on-film can be facilitated. That is, it becomes possible to further reduce the pitch of the pad electrodes 121 and to increase the number of pixels and enhance the functionality of the display device.

[0045] Note that also in the present embodiment, it is preferable to design the insulating layer thickness T4 to be smaller than the sum of the layer thickness T2 of the pixel isolation insulating layer 216 and the layer thickness T3 of the transparent insulating layer 214 in the pixel arrangement region 110 (on the reflective layer) at least in part on the pad electrode 121. Also, a structure can be adopted in which the density of the pixel isolation insulating layer 216 is greater than the density of the transparent insulating layer 214.

[0046] FIG. 6 shows a modified example of the cross-sectional structure of the display device according to the present embodiment. In FIG. 6, a part of the sealing layer 219 remains so as to cover the ends (side wall portions) of the transparent insulating layer 214, the pixel isolation insulating layer 216, etc. on the pad electrode 121. According to this modified example, since the moisture permeation path to the transparent insulating layer 214 can be restricted by the sealing layer 219 having low moisture permeability, a display device with further improved moisture resistance can be obtained.

[0047] Figs. 7(A) and 7(B) show a method for manufacturing a display device according to this embodiment. Fig. 7(A) shows a cross-sectional structure after forming a sealing layer 219. After that, as shown in Fig. 7(B), a photoresist pattern 701 is formed with at least a part of the pad arrangement region 120 opened. Next, using a known dry etching technique, the sealing layer 219 on the pad arrangement region 120 is removed. Note that when the sealing layer 219 on the pixel isolation insulating layer 216 is removed and dry etching is performed so as to expose the pad electrode 121, the structure of Fig. 5 can be obtained easily. Further, by appropriately adjusting conditions such as the dry etching time, gas flow rate, and plasma power, as shown in Fig. 6, it is also possible to leave a part of the sealing layer 219 on the side wall portion such as the transparent insulating layer 214.

[0048] <Embodiment 3> Embodiment 3 of the present invention will be described. In this embodiment, examples of applying the present invention to various devices will be described.

[0049] Fig. 8 is a schematic diagram showing a display device 1000 which is an example of a display device according to this embodiment. The display device 1000 may include a touch panel 1003, a display panel 1005, a frame 1006, a circuit board 1007, and a battery 1008 between an upper cover 1001 and a lower cover 1009. The display panel 1005 is a display panel (display unit) to which the present invention is applied. For example, the display panel 1005 has a light-emitting device having a structure as shown in Figs. 2, 5, and 6, and performs display using light emitted from the light-emitting device. Flexible printed circuits FPC1002 and 1004 are connected to the touch panel 1003 and the display panel 1005. A control circuit including transistors is printed on the circuit board 1007, and performs various controls such as control of the display panel 1005. The battery 1008 may not be provided if the display device is not a portable device, or may be provided at another position even if it is a portable device. The display device 1000 may have three types of color filters corresponding to red, green, and blue respectively. A plurality of color filters may be arranged in a delta array.

[0050] The display device 1000 may be used for the display unit of a mobile terminal. In that case, the display device 1000 may have both a display function and an operation function. Examples of mobile terminals include mobile phones such as smartphones, tablets, head-mounted displays, and the like.

[0051] The display device 1000 may be used for the display unit of an imaging device having an optical unit with a plurality of lenses and an imaging element that receives light that has passed through the optical unit. The imaging device may have a display unit that displays information (such as an image captured by the imaging element) acquired by the imaging element. Further, the display unit may be a display unit exposed to the outside of the imaging device or a display unit disposed within the viewfinder. The imaging device may be a digital camera, a digital video camera, or the like. Figure 9(A) is a schematic diagram showing an imaging device 1100, which is an example of the imaging device according to the present embodiment. The imaging device 1100 may include a viewfinder 1101, a rear display 1102, an operation unit 1103, and a housing 1104. The viewfinder 1101 may be a display unit (display device) to which the present invention is applied. In that case, the viewfinder 1101 may display not only the image to be captured but also environmental information, imaging instructions, and the like. The environmental information may be the intensity of external light, the direction of external light, the speed at which the subject moves, the possibility that the subject is blocked by an obstacle, and the like. The rear display 1102 may also be a display unit to which the present invention is applied.

[0052] Since the timing suitable for imaging is a very short time, it is better to display information as soon as possible. Therefore, it is preferable to use a display device using an organic light-emitting element with a high response speed. A display device using an organic light-emitting element can be more suitably used than a liquid crystal display device or the like in a device that requires a high display speed.

[0053]

[0054] The imaging device 1100 has an optical unit (not shown). The optical unit has a plurality of lenses and forms an image of light on an imaging element housed in the housing 1104. The plurality of lenses can adjust the focus by adjusting their relative positions. This operation can also be performed automatically. The imaging device 1100 may be called a photoelectric conversion device. The photoelectric conversion device may include, as imaging methods, a method of detecting the difference from a previous image instead of performing sequential imaging, a method of cutting out a part of a recorded image, and the like.

[0055] FIG. 9(B) is a schematic diagram showing an example of an electronic device 1200 which is an electronic device according to the present embodiment. The electronic device 1200 includes a display unit 1201, an operation unit 1202, and a housing 1203. The display unit 1201 is a display unit to which the present invention is applied. The housing 1203 of the electronic device 1200 may include a circuit, a printed circuit board having the circuit, a battery, and a communication unit for communicating with the outside. The operation unit 1202 may be a button or a reaction unit of a touch panel method. The operation unit may be a biometric recognition unit that recognizes a fingerprint and performs operations such as unlocking. An electronic device having a communication unit may also be called a communication device. The electronic device may further have a camera function by including a lens and an imaging element. An image captured by the camera function is displayed on the display unit. Examples of the electronic device include a smartphone and a notebook personal computer.

[0056] FIG. 10(A) is a schematic diagram showing an example of a display device 1300 which is a display device according to the present embodiment. The display device 1300 is a display device such as a TV monitor or a PC monitor. The display device 1300 includes a frame 1301, a display unit 1302, and a base 1303 that supports the frame 1301 and the display unit 1302. The display unit 1302 is a display unit to which the present invention is applied. The form of the base 1303 is not limited to the form shown in FIG. 10(A). The lower side of the frame 1301 may also serve as the base 1303. Further, the frame 1301 and the display unit 1302 may be bent. The radius of curvature thereof may be 5000 mm or more and 6000 mm or less.

[0057] FIG. 10(B) is a schematic diagram showing a display device 1310 which is an example of another display device according to the present embodiment. The display device 1310 is a so-called foldable display device configured to be foldable. The display device 1310 includes a first display unit 1311, a second display unit 1312, a housing 1313, and a bending point 1314. Each of the first display unit 1311 and the second display unit 1312 is a display unit to which the present invention is applied. The first display unit 1311 and the second display unit 1312 may be a single seamless display unit. The first display unit 1311 and the second display unit 131 2 can be separated at the bending point. The first display unit 1311 and the second display unit 1312 may display different images, or may display one image on the first display unit 1311 and the second display unit 1312 together.

[0058] FIG. 11(A) is a schematic diagram showing a lighting device 1400 which is an example of a lighting device according to the present embodiment. The lighting device 1400 may include a housing 1401, a light source 1402, a circuit board 1403, an optical film 1404, and a light diffusing unit 1405. The light source 1402 has a light emitting device to which the present invention is applied. The optical film 1404 may be a filter (optical filter) for improving the color rendering property of the light source 1402. The light diffusing unit 1405 can effectively diffuse the light of the light source 1402, such as for lighting up, and deliver the light to a wide area. The optical film 1404 and the light diffusing unit 1405 may be provided on the light emitting side of the lighting device 1400. If necessary, a cover may be provided on the outermost side.

[0059] The lighting device 1400 is a device for lighting, for example, an indoor space. The lighting device 1400 may emit white light, daylight white light, or other colors (any color from blue to red). White light is a color with a color temperature of 4200K, and daylight white light is a color with a color temperature of 5000K. The lighting device 1400 may have a dimming circuit for dimming the emission color of the lighting device 1400. The lighting device 1400 may have a power supply circuit connected to the light source 1402. The power supply circuit is a circuit that converts an alternating voltage into a direct current voltage. Further, the lighting device 1400 may have a color filter. Also, the lighting device 1400 may have a heat dissipation part. The heat dissipation part discharges the heat inside the device to the outside of the device, and examples thereof include metals with high specific heat and liquid silicone.

[0060] FIG. 11(B) is a schematic diagram showing an automobile 1500, which is an example of a moving body according to the present embodiment. The automobile 1500 may have a tail lamp 1501, which is an example of a lighting device. The tail lamp 1501 lights up in response to a brake operation or the like.

[0061] The tail lamp 1501 has a light emitting device to which the present invention is applied. The tail lamp 1501 may have a protection member for protecting the light emitting device. The protection member has a certain degree of strength and may be made of any material as long as it is transparent, but is preferably made of polycarbonate or the like. A phthalic acid derivative, an acrylonitrile derivative, or the like may be mixed into the polycarbonate.

[0062] The automobile 1500 may have a vehicle body 1503 and a window 1502 attached to the vehicle body 1503. The window 1502 may be a transparent display as long as it is not a window for checking the front and rear of the automobile 1500. The transparent display may have a light emitting device to which the present invention is applied. In this case, constituent materials such as electrodes included in the light emitting device are made of transparent members.

[0063] The moving body according to the present embodiment may be a ship, an aircraft, a drone, or the like. The moving body may have a body and a lighting device provided on the body. The lighting device may emit light for notifying the position of the body. The lighting device has a light emitting device to which the present invention is applied.

[0064] The display device according to the present embodiment can be applied to wearable devices such as smart glasses, HMDs, and smart contacts. The display device according to the present embodiment can also be applied to a system having a wearable device or the like. An imaging display device used as a wearable device or the like includes an imaging device capable of photoelectrically converting visible light and a display device capable of emitting visible light.

[0065] FIG. 12(A) is a schematic diagram showing an example of a wearable device, glasses 1600 (smart glasses), according to the present embodiment. An imaging device 1602 such as a CMOS sensor or a SPAD is provided on the front surface side of the lens 1601 of the glasses 1600. Further, on the back surface side of the lens 160 1, a display device according to the present embodiment is provided.

[0066] The glasses 1600 further include a control device 1603. The control device 1603 functions as a power source that supplies power to the imaging device 1602 and the above-described display device. Further, the control device 1603 controls the operations of the imaging device 1602 and the display device. An optical system for condensing light onto the imaging device 1602 is formed in the lens 1601.

[0067] FIG. 12(B) is a schematic diagram showing an example of a wearable device, glasses 1610 (smart glasses), according to the present embodiment. The glasses 1610 have a control device 1612, and an imaging device corresponding to the imaging device 1602 and a display device according to the present embodiment are mounted on the control device 1612. An optical system for projecting light emitted from the imaging device and the display device is formed in the lens 1611, and an image is projected onto the lens 1611. The control device 1612 functions as a power source that supplies power to the imaging device and the display device, and controls the operations of the imaging device and the display device.

[0068] The control device may have a line-of-sight detection unit that detects the line of sight of the wearer of the glasses 1610. The detection of the line of sight may use infrared rays. The infrared light emitting unit emits infrared light to the eyes of the user who is gazing at the display image. An imaging image of the eyes is obtained by the imaging unit having a light receiving element detecting the reflected light of the emitted infrared light from the eyes. By having a reduction unit that reduces the light from the infrared light emitting unit to the display unit in a plan view, the degradation of the quality of the image projected from the display device to the lens 1611 is reduced. The line of sight of the user with respect to the display image is detected from the imaging image of the eyes obtained by imaging the infrared light. Any known method can be applied to the line-of-sight detection using the imaging image of the eyes. As an example, a line-of-sight detection method based on the Purkinje image by the reflection of the irradiation light on the cornea can be used. More specifically, a line-of-sight detection process based on the pupil corneal reflection method is performed. By using the pupil corneal reflection method, a line-of-sight vector representing the orientation (rotation angle) of the eyes is calculated based on the image of the pupil and the Purkinje image included in the imaging image of the eyes, whereby the line of sight of the user is detected.

[0069] In addition, when performing display control based on visual recognition detection (line-of-sight detection), the present invention can be preferably applied to smart glasses having an imaging device that images the outside. The smart glasses can display the imaged external information in real time.

[0070] In addition, the display device according to the present embodiment may have an imaging device having a light receiving element, and may control the display image based on the line-of-sight information of the user from the imaging device. Specifically, based on the line-of-sight information, a first visual field region that the user gazes at and a second visual field region other than the first visual field region are determined. The first visual field region and the second visual field region may be determined by the control device of the display device, or the display device may receive those determined by an external control device. In the display region of the display device, the display resolution of the first visual field region may be controlled to be higher than the display resolution of the second visual field region. That is, the resolution of the second visual field region may be made lower than that of the second visual field region.

[0071] In addition, the display area has a first display area and a second display area different from the first display area, and based on the line-of-sight information, an area with a higher priority may be determined from the first display area and the second display area. The first display area and the second display area may be determined by the control device of the display device, or the display device may receive those determined by an external control device. The resolution of the area with a higher priority may be controlled to be higher than the resolution of the areas other than the area with a higher priority. That is, the resolution of the area with a relatively low priority may be lowered.

[0072] Note that AI may be used to determine the first visual field area, the area with a higher priority, etc. AI is a model configured to estimate the angle of the line of sight and the distance to the object at the tip of the line of sight from the image of the eyeball, using the image of the eyeball and the direction in which the eyeball of the image is actually looking as teacher data. This may be the case. The AI program may be possessed by the display device, the imaging device, or an external device. When it is possessed by an external device, it is transmitted to the display device via communication.

[0073] As described above, by using the present invention in various devices, it is possible to perform display with good image quality or perform good light emission.

Description of Reference Numerals

[0074] 100: Display device 200: Silicon substrate 212: Reflective layer 214: Transparent insulating layer (first insulating layer) 215: Transparent electrode (first electrode) 216: Pixel separation insulating layer (second insulating layer) 217: Organic layer 218: Upper electrode (second electrode) 219: Encapsulation layer (third insulating layer) 121: Pad electrode

Claims

1. It has an element region on a substrate where a light-emitting element is disposed, and a terminal region where a terminal portion electrically connected to the light-emitting element is disposed. The light-emitting element includes, in order from the substrate side, a reflective layer, a first insulating layer, a first electrode, a second insulating layer, an organic layer including a light-emitting layer, a second electrode, and a third insulating layer. The terminal portion has a pad electrode made of the same material as the reflective layer. The pad electrode has an exposed portion where the surface on the side far from the substrate is exposed. The third insulating layer extends from the element region to the edge of the exposed portion in the terminal region. A light-emitting device characterized by the above.

2. The third insulating layer surrounds the edge of the exposed portion. The light-emitting device according to claim 1, characterized by the above.

3. The third insulating layer and the pad electrode are in contact with each other over the entire circumference of the edge of the exposed portion. The light-emitting device according to claim 1 or 2, characterized by the above.

4. The reflective layer and the pad electrode are disposed in the same layer. The light-emitting device according to any one of claims 1 to 3, characterized by the above.

5. It has a wiring layer including wiring made of a material different from that of the reflective layer between the substrate and the reflective layer. The light-emitting device according to any one of claims 1 to 4, characterized by the above.

6. On at least a part of the pad electrode, the total thickness of the first insulating layer and the second insulating layer is smaller than the total thickness of the first insulating layer and the second insulating layer on the reflective layer. The light-emitting device according to any one of claims 1 to 5, characterized by the above.

7. The first insulating layer and the second insulating layer extend from the element region to the pad electrode in the terminal region. The light-emitting device according to any one of claims 1 to 6, characterized by the above.

8. On the pad electrode, the ends of the first insulating layer and the second insulating layer are covered by the third insulating layer. The light-emitting device according to any one of claims 1 to 7, characterized by the above.

9. The first insulating layer and the second insulating layer contain silicon oxide, and the third insulating layer contains silicon nitride. The light-emitting device according to any one of claims 1 to 8, characterized by the above.

10. The density of the second insulating layer is greater than the density of the first insulating layer. The light-emitting device according to any one of claims 1 to 9, characterized by the above.

11. On a substrate, there are an element region where a light-emitting element is disposed, and a terminal region where a terminal portion electrically connected to the light-emitting element is disposed. The light-emitting element includes, in order from the substrate side, a reflective layer, a first insulating layer, a first electrode, a second insulating layer, an organic layer including a light-emitting layer, a second electrode, and a third insulating layer. The terminal portion has a pad electrode made of the same material as the reflective layer. The pad electrode has an exposed portion where the surface on the side far from the substrate is exposed. In at least a part of the pad electrode, the total thickness of the first insulating layer and the second insulating layer is smaller than the total thickness of the first insulating layer and the second insulating layer on the reflective layer. A light-emitting device characterized by the above.

12. Between the substrate and the reflective layer, there is a wiring layer including a wiring made of a material different from that of the reflective layer. The light-emitting device according to claim 11, characterized by the above.

13. The first insulating layer and the second insulating layer contain silicon oxide, and the third insulating layer contains silicon nitride. The light-emitting device according to any one of claims 11 or 12, characterized by the above.

14. The density of the material of the second insulating layer is greater than the density of the material of the first insulating layer. The light-emitting device according to any one of claims 11 to 13, characterized by the above.

15. In the terminal region, the third insulating layer is not provided in at least a part of the portion where the exposed portion is located and at least a part of the other portion. The light-emitting device according to any one of claims 11 to 14, characterized by the above.

16. On the pad electrode, the ends of the first insulating layer and the second insulating layer are covered by the third insulating layer. The light-emitting device according to claim 15, characterized by the above.

17. A display device having a display portion having the light-emitting device according to any one of claims 1 to 16, and a control circuit for controlling the display portion. Characterized by having the above.

18. An optical unit, an imaging element that receives light that has passed through the optical unit, and a display portion that displays an image captured by the imaging element. Characterized by having the above. The display portion has the light-emitting device according to any one of claims 1 to 16. A photoelectric conversion device characterized by the above.

19. A display portion having the light-emitting device according to any one of claims 1 to 16, a housing in which the display portion is provided, and a communication portion provided in the housing for communicating with the outside. An electronic device characterized by having the above.

Images