Manufacturing method for display device, and display device

Abstract

A manufacturing method for a display device comprising a first light-emitting element and a second light-emitting element on a substrate (3) includes vapor deposition of at least a part of a first charge transport layer (22R) of the first light-emitting element using a first vapor deposition mask (M1) having an opening (M11) at a position overlapping the formation position of the first light-emitting element in plan view of the substrate. In vapor deposition using the first vapor deposition mask, at least a part of a second charge transport layer (22G) of the second light-emitting element is formed.

Description

Display device manufacturing method, display device

[0001] The present disclosure relates to a display device including a plurality of light-emitting elements and a method for manufacturing the display device.

[0002] A known thin film formation method is a vapor deposition method in which a material in a crucible is melted and evaporated using a heater, and then brought into contact with the surface of an object positioned above the crucible and solidified to form a thin film containing the material on the surface of the object. Furthermore, in a manufacturing method of a display device including light-emitting elements such as OLEDs, a vapor deposition method using a vapor deposition apparatus is sometimes adopted to form each layer of the light-emitting element in order to reduce deterioration of the layers. Patent Document 1 discloses a method for forming organic layers of an organic EL element in a vapor deposition process using a vapor deposition apparatus.

[0003] Japanese Patent Application Publication No. 2010-40529

[0004] A known technique for display devices is to form a cavity between light-reflective electrodes of light-emitting elements and design the cavity so that light from the light-emitting layer is reinforced within the cavity. This improves the light extraction efficiency of each light-emitting element, thereby improving light emission efficiency, and also narrows the half-width of the light from each light-emitting element, thereby improving display quality.

[0005] In this case, the appropriate distance between the light-emitting layer and the reflective electrode in the light-emitting element varies depending on the wavelength of the light emitted by the light-emitting layer. Therefore, in the manufacturing process of a display device including multiple light-emitting elements that emit different colors, it is necessary to change the thickness of the charge transport layer between the light-emitting layer and the reflective electrode depending on the color of light emitted by the light-emitting element.

[0006] When the thickness of the charge transport layer is changed according to the emission color of the light-emitting element while forming the charge transport layer by vapor deposition using the technique described in Patent Document 1, a process for forming the charge transport layer is required for each emission color of the light-emitting element, which results in the process becoming more complicated or in an increase in costs due to the need for an additional chamber for performing the process.

[0007] A method for manufacturing a display device according to one aspect of the present disclosure is a method for manufacturing a display device including a substrate, a first light-emitting element on the substrate, and a second light-emitting element on the substrate that emits light different from that of the first light-emitting element, wherein the first light-emitting element includes a first anode and a first cathode, one of which is a first reflective electrode and facing each other, a first light-emitting layer between the first anode and the first cathode, and a first charge transport layer between the first reflective electrode and the first light-emitting layer, and the second light-emitting element includes a second anode and a second cathode, one of which is a second reflective electrode and facing each other, a second light-emitting layer between the second anode and the second cathode, and a second charge transport layer between the second reflective electrode and the second light-emitting layer, the method including vapor-depositing at least a portion of the first charge transport layer using a first vapor deposition mask having an opening at a position that overlaps with a formation position of the first light-emitting element in a planar view of the substrate, and depositing at least a portion of the second charge transport layer during the vapor deposition using the first vapor deposition mask.

[0008] a first light-emitting element on the substrate; a second light-emitting element on the substrate that emits light different from that of the first light-emitting element; and a bank located on the substrate and between the first light-emitting element and the second light-emitting element in a planar view of the substrate, wherein the first light-emitting element comprises a first anode and a first cathode, one of which is a first reflective electrode and facing each other, a first light-emitting layer between the first anode and the first cathode, and a first charge transport layer between the first reflective electrode and the first light-emitting layer; the second light-emitting element comprises a second anode and a second cathode, one of which is a second reflective electrode and facing each other, a second light-emitting layer between the second anode and the second cathode, and a second charge transport layer between the second reflective electrode and the second light-emitting layer, wherein the bank separates at least the first charge transport layer and the second charge transport layer, and a layer containing a material contained in the first charge transport layer is located on a side of the bank adjacent to the second light-emitting element.

[0009] The manufacturing method of the display device is further simplified, and the manufacturing cost or takt time is further reduced.

[0010] FIG. 1 is a cross-sectional side view of a process of a manufacturing method for a display device according to embodiment 1. FIG. 2 is a schematic plan view of a display device according to embodiment 1. FIG. 3 is a schematic cross-sectional side view of a display device according to embodiment 1. FIG. 4 is a flowchart of a manufacturing method for a display device according to embodiment 1. FIG. 5 is a schematic plan view of a vapor deposition apparatus according to embodiment 1. FIG. 6 is a cross-sectional side view of another process of a manufacturing method for a display device according to embodiment 1. FIG. 7 is a schematic cross-sectional side view of a display device according to embodiment 2. FIG. 8 is a flowchart of a manufacturing method for a display device according to embodiment 2. FIG. 9 is a cross-sectional side view of a process of a manufacturing method for a display device according to embodiment 2. FIG. 10 is a cross-sectional side view of a display device according to embodiment 3. FIG. 11 is a flowchart of a manufacturing method for a display device according to embodiment 3. FIG. 12 is a cross-sectional side view of a display device according to embodiment 4. FIG. 13 is a cross-sectional side view of a process of a manufacturing method for a display device according to embodiment 4. FIG. 14 is a cross-sectional side view of a display device according to embodiment 5. FIG. 15 is a flowchart of a manufacturing method for a display device according to embodiment 5.

[0011] [Embodiment 1] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. Note that in each drawing, similar configurations are assigned the same reference numerals, and their description will be omitted. Furthermore, in this disclosure, for simplicity of illustration, components assigned the same reference numerals may be shown at different scales or with different hatching depending on the drawing. However, the components shown in each drawing of the present disclosure are merely examples, and the scales are not limited to those shown in the drawings. Furthermore, in this disclosure, even for components with different hatching, components assigned the same reference numerals have similar configurations as described above.

[0012] <Display Device> The present disclosure relates to a display device provided with a light-emitting element including a layer partially formed by vapor deposition. First, an example of a display device according to the present disclosure will be described.

[0013] FIG. 2 is a schematic plan view of a display device 1 according to this embodiment. The display device 1 is a device that can be used, for example, as a display for a television or a smartphone. As shown in FIG. 2, the display device 1 includes a frame area NDA and a display area DA. The display area DA of the display device 1 includes a plurality of pixels P, each of which includes a red subpixel RSP, a green subpixel GSP, and a blue subpixel BSP. However, this embodiment is not limited to this. For example, the pixel P may include subpixels of other colors in addition to the red subpixel RSP, the green subpixel GSP, and the blue subpixel BSP.

[0014] The display device 1 includes light-emitting elements (described later) in the red subpixels RSP, green subpixels GSP, and blue subpixels BSP. In particular, the light-emitting elements in the red subpixels RSP emit red light, the light-emitting elements in the green subpixels GSP emit green light, and the light-emitting elements in the blue subpixels BSP emit blue light. The display device 1 performs full-color display in the display area DA by controlling the light emission from each light-emitting element in the display area DA via, for example, a driver circuit and a pixel circuit (not shown) formed in the frame area NDA.

[0015] <Light-emitting element: overview> The structure of the display area DA of the display device 1, particularly the structure of the light-emitting element of each subpixel, will be described in more detail with reference to Fig. 3. Fig. 3 is a schematic side cross-sectional view of the display device 1 according to an embodiment of the present disclosure, particularly showing a cross section perpendicular to the display surface of the display device 1 and passing through the red subpixel RSP, the green subpixel GSP, and the blue subpixel BSP.

[0016] The display device 1 includes a red light-emitting element 2R as a first light-emitting element, a green light-emitting element 2G as a second light-emitting element, and a blue light-emitting element 2B as a third light-emitting element, on a substrate 3. The red light-emitting element 2R, the green light-emitting element 2G, and the blue light-emitting element 2B emit red light, green light, and blue light, respectively, toward the display surface of the display device 1.

[0017] In this embodiment, red light refers to light having a central emission wavelength in a wavelength band of more than 600 nm and not more than 780 nm. Green light refers to light having a central emission wavelength in a wavelength band of more than 500 nm and not more than 600 nm. Blue light refers to light having a central emission wavelength in a wavelength band of not less than 380 nm and not more than 500 nm.

[0018] In other words, the green light emitting element 2G emits light different from that of the red light emitting element 2R, and in particular the central wavelength of the light emitted by the red light emitting element 2R is longer than that of the light emitted by the green light emitting element 2G. Furthermore, the blue light emitting element 2B emits light different from both the red light emitting element 2R and the green light emitting element 2G, and in particular the central wavelength of the light emitted by the green light emitting element 2G is longer than that of the light emitted by the blue light emitting element 2B.

[0019] The display device 1 includes a red light-emitting element 2R in the red sub-pixel RSP, a green light-emitting element 2G in the green sub-pixel GSP, and a blue light-emitting element 2B in the blue sub-pixel BSP. The display device 1 controls the red light from the red light-emitting element 2R, the green light from the green light-emitting element 2G, and the blue light from the blue light-emitting element 2B for each light-emitting element via, for example, the driver circuit and pixel circuit (not shown) described above, to perform display in the display area DA. This allows the display device 1 to perform full-color display on the display surface of the display area DA.

[0020] The red light-emitting element 2R includes a first anode 21R, a first hole transport layer 22R as a first charge transport layer, a red light-emitting layer 23R as a first light-emitting layer, an electron transport layer 24, and a cathode 25, laminated in this order from the substrate 3 side. The green light-emitting element 2G includes a second anode 21G, a second hole transport layer 22G as a second charge transport layer, a green light-emitting layer 23G as a second light-emitting layer, an electron transport layer 24, and a cathode 25, laminated in this order from the substrate 3 side. The blue light-emitting element 2B includes a third anode 21B, a third hole transport layer 22B as a third charge transport layer, a blue light-emitting layer 23B as a third light-emitting layer, an electron transport layer 24, and a cathode 25, laminated in this order from the substrate 3 side.

[0021] <Light-emitting element: bank> The display device 1 further includes a bank BK on the substrate 3. The bank BK separates the light-emitting elements into subpixels. In particular, the bank BK according to this embodiment separates the anode and light-emitting layer of each light-emitting element into subpixels. The bank BK may contain, for example, a resin material, and may be made of a transparent resin such as polyimide having light-transmitting properties. The bank BK may also have, on its surface on the cathode 25 side, a mask spacer that comes into contact with a vapor deposition mask (described later) as a convex portion that protrudes from the substrate 3 side toward the cathode 25 side.

[0022] Here, the display device 1 includes an electron transport layer 24 and a cathode 25 that are common to multiple subpixels. Therefore, each light-emitting element includes the electron transport layer 24 and the cathode 25 located in the corresponding subpixel as the electron transport layer and cathode of the light-emitting element. In particular, the red light-emitting element 2R includes the cathode 25 located in the red subpixel RSP as the first cathode. The green light-emitting element 2G includes the cathode 25 located in the green subpixel GSP as the second cathode. The blue light-emitting element 2B includes the cathode 25 located in the blue subpixel BSP as the third cathode.

[0023] Therefore, the red light-emitting element 2R includes a red light-emitting layer 23R between the first anode 21R and the first cathode, the green light-emitting element 2G includes a green light-emitting layer 23G between the second anode 21G and the second cathode, and the blue light-emitting element 2B includes a blue light-emitting layer 23B between the third anode 21B and the third cathode.

[0024] <Light-Emitting Element: Common Layer> The display device 1 further includes a first common layer 31 common to multiple subpixels, located between the anode and light-emitting layer of each light-emitting element and serving as at least a portion of the hole transport layer of each light-emitting element. In this embodiment, the red light-emitting element 2R includes a portion of the first common layer 31 located in the red subpixel RSP as a first hole transport layer 22R. The green light-emitting element 2G includes a portion of the first common layer 31 located in the green subpixel GSP as a second hole transport layer 22G. The blue light-emitting element 2B includes a portion of the first common layer 31 located in the blue subpixel BSP as a third hole transport layer 22B. Therefore, the bank BK can be considered to separate at least the first hole transport layer 22R, the second hole transport layer 22G, and the third hole transport layer 22B.

[0025] The first common layer 31 is also formed on the surface of the bank BK between the subpixels. Therefore, a part of the first common layer 31 is located on the side of the bank BK adjacent to the green light-emitting element 2G as a layer containing a material contained in the first hole transport layer 22R. Furthermore, a part of the first common layer 31 is located on the side of the bank BK adjacent to the blue light-emitting element 2B as a layer containing at least one of a material contained in the first hole transport layer 22R and a material contained in the second hole transport layer 22G.

[0026] In this embodiment, the thickness of the portion of the first common layer 31 located in the red subpixel RSP is greater than the thickness of the portions located in the green subpixel GSP and the blue subpixel BSP, and therefore the thickness of the first hole transport layer 22R is greater than the thickness of the second hole transport layer 22G and the thickness of the third hole transport layer 22B.

[0027] In general, the appropriate optical path length of the cavity formed between the light-emitting layer and the reflective electrode of the light-emitting element is an integer multiple of the wavelength of the light emitted by the light-emitting layer. Therefore, in general, when forming a cavity in the light-emitting element, the appropriate distance between the light-emitting layer and the reflective electrode increases in proportion to the wavelength of the light emitted by the light-emitting layer.

[0028] With the above configuration, the distance between the red light-emitting layer 23R and the first anode 21R is longer than the distance between the green light-emitting layer 23G and the second anode 21G. Therefore, the display device 1 can make the optical path lengths of the cavities more appropriate in the red light-emitting element 2R and the green light-emitting element 2G, and can extract light more efficiently from the red light-emitting element 2R and the green light-emitting element 2G.

[0029] In this embodiment, each light-emitting element has an anode located closer to the substrate 3 than the light-emitting layer, as a reflective electrode. Therefore, in the display device 1 according to this embodiment, light from the light-emitting layer of each light-emitting element is extracted from the side opposite the substrate 3. This can improve the aperture ratio of each sub-pixel compared to extracting light from the side of the substrate 3 on which pixel circuits for driving the anodes of each sub-pixel are formed, thereby enabling the display quality of the display device 1 to be further improved.

[0030] Furthermore, the optical path length of the cavity in each light-emitting element is adjusted by adjusting the film thickness of the hole transport layer between the light-emitting layer and the anode located closer to the substrate 3 than the light-emitting layer. Generally, in a display device equipped with light-emitting elements, the light-emitting elements are manufactured by stacking each layer in order from the substrate side, as will be described later. Therefore, with the above configuration, the display device 1 can adjust the film thickness of the hole transport layer of each light-emitting element during the manufacturing process, and then form each layer closer to the cathode 25 than the hole transport layer. Therefore, the display device 1 makes it possible to more easily adjust the optical path length of the cavity of each light-emitting element during the manufacturing process.

[0031] <Light-emitting element: electrodes> The first anode 21R, second anode 21G, and third anode 21B face each other, and the cathode 25 is a reflective electrode that reflects visible light and a transparent electrode that transmits visible light. In particular, in this embodiment, the first anode 21R is a first reflective electrode, the second anode 21G is a second reflective electrode, and the third anode 21B is a third reflective electrode. Therefore, the first hole transport layer 22R is located between the first anode 21R and the red light-emitting layer 23R, the second hole transport layer 22G is located between the second anode 21G and the green light-emitting layer 23G, and the third hole transport layer 22B is located between the third anode 21B and the blue light-emitting layer 23B. The cathode 25 is a transparent electrode.

[0032] The first anode 21R, the second anode 21G, and the third anode 21B may each contain, for example, a metal material. The cathode 25 may be made of a thin metal film that is thin enough to transmit visible light, or may be made of a transparent conductor including an oxide conductor.

[0033] The first anode 21R, the second anode 21G, the third anode 21B, and the cathode 25 may be formed by sputtering or the like. In particular, the first anode 21R, the second anode 21G, and the third anode 21B may be formed by, for example, forming a metal thin film and then patterning the metal thin film by dry etching or the like. However, from the viewpoint of reducing deterioration of layers formed by vapor deposition (described later), the first anode 21R, the second anode 21G, the third anode 21B, and the cathode 25, which are formed after the functional layer, may be formed by vacuum vapor deposition.

[0034] <Light-emitting element: charge transport layer> The hole transport layer of each light-emitting element is a layer containing a hole transport material that transports holes injected from the anode to the light-emitting layer in that light-emitting element. In particular, the first hole transport layer 22R transports holes from the first anode 21R to the red light-emitting layer 23R. The second hole transport layer 22G transports holes from the second anode 21G to the green light-emitting layer 23G. The third hole transport layer 22B transports holes from the third anode 21B to the blue light-emitting layer 23B.

[0035] In this embodiment, the first hole transport layer 22R, the second hole transport layer 22G, and the third hole transport layer 22B can be made of various organic or inorganic materials, including materials conventionally used in light-emitting elements. In particular, in this embodiment, the first hole transport layer 22R, the second hole transport layer 22G, and the third hole transport layer 22B contain materials that can be deposited by vacuum deposition. In other words, in this embodiment, the first common layer 31 contains a hole transport material that can be deposited by vacuum deposition.

[0036] The electron transport layer 24 is a layer containing an electron transport material that transports electrons from the cathode 25 to the light-emitting layer of each light-emitting element. In this embodiment, various organic or inorganic materials, including materials conventionally used in light-emitting elements, can be used as the material for the electron transport layer 24. In particular, in this embodiment, the electron transport layer 24 may contain a material that can be formed into a film by vacuum deposition.

[0037] In this embodiment, each light-emitting element may have a hole injection layer between the anode and the hole transport layer, or may have an electron injection layer between the cathode 25 and the electron transport layer 24. Furthermore, each light-emitting element may have an intermediate layer such as a charge blocking layer between the hole transport layer and the light-emitting layer, or between the electron transport layer 24 and the light-emitting layer. These electron injection layers and intermediate layers may be formed by the same method as that for either the hole transport layer or the electron transport layer 24.

[0038] <Light-Emitting Element: Light-Emitting Layer> The red light-emitting layer 23R, the green light-emitting layer 23G, and the blue light-emitting layer 23B each contain a light-emitting material. The light-emitting material contained in each light-emitting layer emits light by excitons generated by the recombination of holes injected from the anode through the hole transport layer and electrons injected from the cathode 25 through the electron transport layer 24. In this embodiment, each light-emitting layer is made of a material that can be formed into a film by vacuum deposition. For example, each light-emitting layer may contain at least one of an organic fluorescent material and an organic phosphorescent material as the light-emitting material. The light-emitting material contained in each light-emitting layer may be selected appropriately depending on the emission color of the subpixel in which the light-emitting element is located. For example, the red light-emitting layer 23R, the green light-emitting layer 23G, and the blue light-emitting layer 23B each contain a light-emitting material that emits red light, green light, and blue light, respectively.

[0039] <Manufacturing Method of Display Device: Up to Formation of Banks> A manufacturing method of the display device 1 according to this embodiment will be described with reference to Fig. 4. Fig. 4 is a flowchart of the manufacturing method of the display device 1 according to this embodiment.

[0040] In the manufacturing method of the display device 1 according to this embodiment, first, a substrate 3 is prepared (step S1). The substrate 3 may be formed by forming pixel circuits and drivers for driving light-emitting elements of each sub-pixel on a substrate such as a glass substrate or a film substrate.

[0041] Next, an anode is formed for each light-emitting element (step S2). Specifically, in step S2, a first anode 21R, a second anode 21G, and a third anode 21B are formed on the substrate 3. Each anode may be formed by forming a thin conductive film common to multiple subpixels by the method described above, and then patterning the thin film for each subpixel. Alternatively, each anode may be formed by vacuum deposition using a deposition mask having openings at positions overlapping the corresponding subpixels. In this case, the anodes may be formed using a deposition apparatus described below.

[0042] Next, banks BK are formed on the substrate 3 (step S3). The banks BK may be formed, for example, by applying a photosensitive resin onto the substrate 3 and each anode, and then patterning the resin by photolithography. The banks BK may be formed between multiple anodes, and a portion of the banks BK may be formed at the end of each anode.

[0043] <Display Device Manufacturing Method: Vapor Deposition Apparatus> Next, the first common layer 31 is formed (step S4). Specifically, in step S4, the first common layer 31 is formed on the first anode 21R, the second anode 21G, the third anode 21B, and the bank BK. In this embodiment, the first common layer 31 is formed by vacuum vapor deposition using a vapor deposition apparatus.

[0044] An example of a vapor deposition apparatus according to this embodiment will be described with reference to FIG. 5 . FIG. 5 is a schematic plan view of a vapor deposition apparatus 4 according to this embodiment. However, in FIG. 5 , the interior of a chamber 41, which will be described later, is shown in a see-through manner in order to clearly show each part of the vapor deposition apparatus 4. Also, in FIG. 5 , the outline of the substrate 3 stored inside the chamber 41 during vapor deposition on the substrate 3 is shown by a dotted line in order to clearly show the positional relationship between each part of the vapor deposition apparatus 4 and the substrate 3 that is the target of vapor deposition. As shown in FIG. 5 , the vapor deposition apparatus 4 includes a chamber 41 and a crucible 42.

[0045] The chamber 41 is a vacuum chamber whose interior can be made substantially vacuum by a pump (not shown) or the like. The chamber 41 may have an opening (not shown) that allows the substrate 3 to be moved in and out of the chamber 41 and that allows the chamber 41 to be sealed.

[0046] The crucible 42 can store therein a vapor deposition material containing a material to be vapor-deposited on the substrate 3, which is the target of vapor deposition. The crucible 42 has a plurality of vapor deposition holes 43 that communicate between the inside and outside of the crucible 42 on the side of the substrate 3. The crucible 42 heats and sublimes the vapor deposition material stored therein using a heater (not shown) or the like. This allows the vapor deposition device to release the vapor deposition material from the inside of the crucible 42 through the plurality of vapor deposition holes 43 to the substrate 3, thereby vapor-depositing the vapor deposition material onto the substrate 3.

[0047] The crucible 42 is located inside the chamber 41 and is moved inside the chamber 41 by a power unit (not shown). For example, in a plan view of the substrate 3, the substrate 3 has a first end 3A that is one end and a second end 3B that is the other end opposite the first end 3A. The crucible 42 is movable in a first direction T1 that is the direction from the first end 3A to the second end 3B, and in a second direction T2 that is the direction opposite to the first direction T1, in other words, from the second end 3B to the first end 3A.

[0048] The crucible 42 may move in the first direction T1 or the second direction T2 while heating the evaporation material. This allows the evaporation device 4 to emit the evaporation material onto each portion of the substrate 3 from the first end 3A to the second end 3B using the crucible 42, without requiring a crucible 42 that overlaps the entire substrate 3 in a plan view of the substrate 3. This allows the evaporation device 4 to more efficiently form an evaporated film on the substrate 3 while reducing the size of the crucible 42. Furthermore, when evaporation is performed on the substrate 3 while moving the crucible 42 in the first direction T1 or the second direction T2, the evaporation device 4 may control the film thickness of the evaporated film formed on the substrate 3 by changing the moving speed of the crucible 42.

[0049] <Display Device Manufacturing Method: Formation of First Common Layer> The formation of the first common layer 31 using the vapor deposition apparatus 4 will be further described with reference to Fig. 6 and Fig. 1. Fig. 6 and Fig. 1 are side cross-sectional views of the process of the manufacturing method of the display device 1 according to this embodiment, and in particular, are side cross-sectional views of the process of step S4. In the present disclosure, the side cross-sectional views of the process of the manufacturing method of the display device 1 show a cross section corresponding to the cross section of the display device 1 shown in Fig. 3.

[0050] In forming the first common layer 31, first, the material for the first common layer 31 is placed as a vapor deposition material in the crucible 42 of the vapor deposition device 4. Next, the substrate 3 on which the anodes and banks BK have been formed is placed in the chamber 41 so that the anodes are located closer to the crucible 42 than the substrate 3, and the chamber 41 is evacuated to a substantial vacuum. Next, as shown in step S4-1 in FIG. 6 , the first vapor deposition mask M1 is placed closer to the anodes than the substrate 3. In other words, the crucible 42 is placed closer to the first vapor deposition mask M1 than the substrate 3.

[0051] The first vapor deposition mask M1 is a vapor deposition mask that has openings M11 at positions overlapping with the red sub-pixels RSP, in other words, positions overlapping with positions where the first hole transport layers 22R are to be formed, in a plan view of the substrate 3. The first vapor deposition mask M1 may be made of a metal material with a relatively small coefficient of thermal expansion, such as invar, or may be made of a magnetic material.

[0052] In forming the vapor-deposited film according to the present disclosure, including step S4, the touch plate TP and the magnet MG may be disposed on the opposite side of the substrate 3 from the anodes, as shown in step S4-1 in FIG.

[0053] The touch plate TP is a flat plate having a predetermined rigidity and is made of, for example, resin. In the formation of the deposited film according to the present disclosure, the touch plate TP abuts against the side of the substrate 3 opposite the anodes. This reduces the deflection of the substrate 3 during the formation of the deposited film, further improving the accuracy of the deposition position of the deposited film.

[0054] The magnet MG is located on the opposite side of the touch plate TP from the substrate 3, and attracts the deposition masks made of a magnetic material, including the first deposition mask M1. This allows the magnet MG to reduce deflection of the deposition masks, including the first deposition mask M1, relative to the substrate 3 during the formation of the deposition film, thereby further improving the accuracy of the deposition position of the deposition film.

[0055] In step S4, in other words, in forming the first common layer 31, the distance between the magnet MG and the touch plate TP may be a distance D1, as shown in step S4-1 of FIG.

[0056] 6, in step S4, in other words, in forming the first common layer 31, the first vapor deposition mask M1 is placed below the bank BK, in other words, the first vapor deposition mask M1 is placed away from the bank BK. In this state, in step S4, a vapor deposition material containing the material of the first common layer 31 is released from the crucible 42.

[0057] 1, in step S4, the vapor deposition material containing the material of the first common layer 31 passes through the opening M11 of the first vapor deposition mask M1 and reaches the red subpixel RSP. As a result, in step S4, the first hole transport layer 22R including part of the first common layer 31 is formed on the first anode 21R. In addition, in step S4, part of the first common layer 31 is also formed on the side surface of the bank BK adjacent to the red subpixel RSP.

[0058] On the other hand, in step S4, a gap is formed between the first vapor deposition mask M1 and the bank BK. Therefore, in step S4, the vapor deposition material emitted from the crucible 42 reaches the green sub-pixel GSP and the blue sub-pixel BSP through the opening M11 of the first vapor deposition mask M1.

[0059] Therefore, in step S4, the second hole transport layer 22G including a part of the first common layer 31 is formed on the second anode 21G, and the third hole transport layer 22B including a part of the first common layer 31 is formed on the third anode 21B. In other words, in the vapor deposition using the first vapor deposition mask M1 according to this embodiment, at least a part of the second hole transport layer 22G and at least a part of the third hole transport layer 22B are formed.

[0060] FIG. 7 is a schematic diagram illustrating the film formation range of the first common layer 31. In FIG. 7, the positions of parts of the red subpixel RSP, the green subpixel GSP, and the blue subpixel BSP in a plan view of the substrate 3 are indicated by solid lines. Also in FIG. 7, the positions of parts of the openings M11 of the first vapor deposition mask M1 in a plan view of the substrate 3 are indicated by dotted lines. Furthermore, FIG. 7 indicates, by dashed-dotted lines, the formation positions of the first common layer 31 formed by the vapor deposition material that has passed through each opening M11 shown in FIG. 7. As shown in FIG. 7, the first common layer 31 formed by the vapor deposition material that has passed through an opening M11 that overlaps one red subpixel RSP in a plan view of the substrate 3 is also formed in the green subpixels GSP and blue subpixels BSP surrounding the red subpixel RSP.

[0061] As described above, by forming the first common layer 31 in step S4, the first hole transport layer 22R, the second hole transport layer 22G, and the third hole transport layer 22B are formed.

[0062] 1, part of the first common layer 31 is also formed on the side surface of the bank BK adjacent to the green subpixel GSP and the side surface of the bank BK adjacent to the blue subpixel BSP. In step S4, part of the first common layer 31 may also be formed on the surface of the bank BK on the side of the first vapor deposition mask M1.

[0063] However, in a plan view of the substrate 3, the crucible 42 is shielded from the green subpixel GSP and the blue subpixel BSP by the first vapor deposition mask M1. This prevents the vapor deposition material from directly reaching the green subpixel GSP and the blue subpixel BSP in the direction from the crucible 42 toward the substrate 3. Therefore, the film thickness of the portion of the first common layer 31 that is formed in the red subpixel RSP and overlaps with the opening M11 of the first vapor deposition mask M1 in a plan view of the substrate 3 is greater than the film thickness of the portion that is formed in the green subpixel GSP and the blue subpixel BSP.

[0064] In other words, the film thickness of the first hole transport layer 22R is greater than the film thickness of the second hole transport layer 22G and the film thickness of the third hole transport layer 22B. As described above, by forming the first common layer 31, it is possible to form the first hole transport layer 22R whose film thickness is greater than the film thickness of the second hole transport layer 22G and the film thickness of the third hole transport layer 22B.

[0065] The formation of the first common layer 31 in step S4 may be performed while moving the crucible 42 in the first direction T1 or the second direction T2. ​​As a result, in step S4, the first common layer 31 may be formed from each sub-pixel located on the first end 3A side of the substrate 3 to each sub-pixel located on the second end 3B side. The film thickness of the first common layer 31 may be adjusted by controlling the moving speed of the crucible 42 in the first direction T1 or the second direction T2.

[0066] <Manufacturing Method of Display Device: Formation of Light-Emitting Layer> Returning to FIG. 4 , following the formation of the first common layer 31, the light-emitting layer of each light-emitting element is formed (step S5). Specifically, in step S5, the red light-emitting layer 23R, the green light-emitting layer 23G, and the blue light-emitting layer 23B are formed on the first common layer 31. The formation of the light-emitting layer of each light-emitting element will be described with reference to FIG. 8 , taking the formation of the red light-emitting layer 23R as an example. FIG. 8 is a side cross-sectional view of a process in the manufacturing method of the display device 1 according to this embodiment, particularly a side cross-sectional view of the process of forming the red light-emitting layer 23R in step S4.

[0067] In forming the red light-emitting layer 23R, first, the material for the red light-emitting layer 23R is placed as a deposition material in the crucible 42 of the deposition device 4. Next, the substrate 3 on which each layer including the first common layer 31 has been formed is placed in the chamber 41 so that each anode is located closer to the crucible 42 than the substrate 3, and the chamber 41 is evacuated to a substantial vacuum. To reduce contamination of the material for the first common layer 31 into the red light-emitting layer 23R, the chamber 41 into which the substrate 3 is placed in step S5 may be different from the chamber 41 into which the substrate 3 is placed in step S4. Next, as shown in step S5 of FIG. 8 , a deposition mask MR for forming the red light-emitting layer 23R is placed closer to each anode than the substrate 3.

[0068] The deposition mask MR has an opening MR1 at a position overlapping with the red sub-pixel RSP, in other words, a position overlapping with a formation position of the red light-emitting layer 23R, in a plan view of the substrate 3. The deposition mask MR may have the same configuration as the first deposition mask M1. However, in step S5, the deposition mask MR is brought into contact with the surface of the bank BK on the crucible 42 side. If the bank BK has mask spacers, the deposition mask MR may be brought into contact with the bank BK by bringing the deposition mask MR into contact with the mask spacers in step S5. Performing deposition with the deposition mask MR in contact with the mask spacers can reduce damage to the bank BK, damage such as peeling of the first common layer 31 formed on the bank BK, or adhesion of the material of the first common layer 31 to the deposition mask MR.

[0069] For this reason, in step S5, no gap is formed between the deposition mask MR and the bank BK. Therefore, the deposition material emitted from the crucible 42 does not reach from the opening MR1 of the deposition mask MR to the green sub-pixel GSP or the blue sub-pixel BSP. Therefore, in step S5, the deposition material reaches only the portion of the first common layer 31 that overlaps with the opening MR1 in a plan view of the substrate 3. Therefore, in step S5, the red light-emitting layer 23R is formed only in the red sub-pixel RSP.

[0070] Also in step S5, the touch plate TP and magnet MG may be disposed on the opposite side of the substrate 3 from the anodes. However, in step S5, the distance between the magnet MG and the touch plate TP may be a distance D2 that is longer than the distance D1 described above.

[0071] In step S5, the deposition mask MR abuts against the bank BK, and therefore the distance between the deposition mask MR and the substrate 3 in step S5 is shorter than the distance between the first deposition mask M1 and the substrate 3 in step S4. Therefore, in step S5, by setting the distance between the magnet MG and the touch plate TP to the distance D2, it is possible to prevent the magnet MG from attracting the deposition mask MR too strongly, thereby reducing distortion of the deposition mask MR.

[0072] The green light-emitting layer 23G and the blue light-emitting layer 23B may each be formed by the same method as the method for forming the red light-emitting layer 23R, except for the positions of the openings in the deposition mask used and the material released from the crucible 42. In particular, the green light-emitting layer 23G may be formed by a vacuum deposition method using a deposition mask having openings in positions overlapping with the green sub-pixels GSP in a planar view of the substrate 3. Furthermore, the blue light-emitting layer 23B may be formed by a vacuum deposition method using a deposition mask having openings in positions overlapping with the blue sub-pixels BSP in a planar view of the substrate 3.

[0073] 4 , after the light-emitting layers of the light-emitting elements are formed, the electron transport layer 24 is formed (step S6). The electron transport layer 24 may be formed by vacuum deposition, from the viewpoint of reducing deterioration of the hole transport layers and the light-emitting layers. In this case, the electron transport layer 24 may be formed by the above-described deposition apparatus 4 using a deposition mask having openings at positions overlapping with the plurality of subpixels in a plan view of the substrate 3, for example, at positions overlapping with the display area DA.

[0074] Next, the cathode 25 is formed (step S7). The cathode 25 may be formed by vacuum deposition from the viewpoint of reducing deterioration of each layer from the hole transport layer to the electron transport layer 24. In this case, the cathode 25 may be formed by the above-described deposition apparatus 4 using a deposition mask having openings at positions overlapping with a plurality of sub-pixels in a plan view of the substrate 3, for example, at positions overlapping with the display area DA. This completes the manufacture of the display device 1.

[0075] <Simplifying Formation of Hole Transport Layers> According to the manufacturing method of the display device 1 according to this embodiment, the first hole transport layer 22R, the second hole transport layer 22G, and the third hole transport layer 22B can be formed by forming the first common layer 31. In other words, in the vapor deposition of at least a portion of the first hole transport layer 22R using the first vapor deposition mask M1 according to this embodiment, at least a portion of the second hole transport layer 22G and at least a portion of the third hole transport layer 22B are formed.

[0076] Therefore, in this embodiment, it is not necessary to individually form the first hole transport layer 22R, the second hole transport layer 22G, and the third hole transport layer 22B. Therefore, according to the manufacturing method of the display device 1 according to this embodiment, the formation of the first hole transport layer 22R, the second hole transport layer 22G, and the third hole transport layer 22B is simplified, and reduction in manufacturing costs or shortening of takt time is achieved.

[0077] In forming the first common layer 31 according to this embodiment, the first hole transport layer 22R, the second hole transport layer 22G, and the third hole transport layer 22B are formed. However, this is not limiting, and in forming the first common layer 31 according to this embodiment, it is sufficient to form at least a portion of the first hole transport layer 22R, and at least a portion of the second hole transport layer 22G or at least a portion of the third hole transport layer 22B.

[0078] For example, in this embodiment, a layer containing a hole transport material may be formed for at least one of the red subpixel RSP, the green subpixel GSP, and the blue subpixel BSP, separately from the formation of the first common layer 31. Furthermore, the display device 1 may include only the red light-emitting element 2R and the green light-emitting element 2G or the blue light-emitting element 2B.

[0079] As described above, in the display device 1 according to this embodiment, a layer containing the material contained in the first hole transport layer 22R is located as the first common layer 31 on the side surface of the bank BK adjacent to the green light-emitting element 2G. Also, in the display device 1 according to this embodiment, a layer containing the material contained in the first hole transport layer 22R and the material contained in the second hole transport layer 22G is located as the first common layer 31 on the side surface of the bank BK adjacent to the blue light-emitting element 2B. Such a display device 1 can be manufactured by a method that includes the formation of the first common layer 31 described above. Therefore, the display device 1 described above can be manufactured by a simplified manufacturing method.

[0080] Furthermore, according to the manufacturing method of the display device 1 of this embodiment, the film thickness of the first hole transport layer 22R can be made larger than the film thickness of the second hole transport layer 22G and the film thickness of the third hole transport layer 22B. Therefore, according to the manufacturing method of the display device 1 of this embodiment, as described above, the formation of each hole transport layer is simplified, the optical path length of the cavity in each light-emitting element is made more appropriate, and the light extraction efficiency from each light-emitting element is improved.

[0081] In this embodiment, the optical path length of the cavity of each light-emitting element can be adjusted by the film thickness of the hole transport layer. Therefore, in this embodiment, there is no need to adjust the film thickness of the electron transport layer 24 in order to adjust the optical path length of the cavity of each light-emitting element. For example, the film thickness of the electron transport layer 24 can be made uniform among multiple subpixels. Therefore, the display device 1 improves the light extraction efficiency from each light-emitting element and improves display quality while simplifying the adjustment of the film thickness of the electron transport layer 24.

[0082] [Embodiment 2] A display device 1 according to another embodiment of the present disclosure will be described. Hereinafter, components having the same configuration as those described in the previous embodiment will be assigned the same component numbers, and descriptions thereof will be omitted.

[0083] 9 is a schematic side cross-sectional view of the display device 1 according to this embodiment. The display device 1 according to this embodiment has the same configuration as the display device 1 according to the previous embodiment, except that it includes an underlayer 51 between each anode and bank BK and the first common layer 31.

[0084] Except for the thickness, the underlayer 51 may have the same configuration as the first common layer 31. For example, the underlayer 51 includes a hole transport material and is located in common with respect to the red subpixel RSP, the green subpixel GSP, and the blue subpixel BSP.

[0085] Therefore, the portions of the base layer 51 that are located in the red subpixel RSP, the green subpixel GSP, and the blue subpixel BSP are part of the first hole transport layer 22R, the second hole transport layer 22G, and the third hole transport layer 22B. In other words, the first hole transport layer 22R, the second hole transport layer 22G, and the third hole transport layer 22B each include the portions of the first common layer 31 and the base layer 51 that are located in the red subpixel RSP, the green subpixel GSP, and the blue subpixel BSP, respectively. The base layer 51 is also located on the side surfaces of the banks BK and on the surface on the cathode 25 side.

[0086] However, the underlayer 51 may have a substantially constant thickness regardless of the subpixel. In the present disclosure, when the difference between the maximum and minimum thicknesses of a given layer on the substrate 3 is 20 nm or less, the thickness of the layer may be considered to be substantially constant. By including the underlayer 51 in the display device 1, the display device 1 can more precisely adjust the optical path length of the cavity of each light-emitting element.

[0087] A method for manufacturing the display device 1 according to this embodiment will be described with reference to Fig. 10 and Fig. 11. Fig. 10 is a flowchart of the method for manufacturing the display device 1 according to this embodiment. Fig. 11 is a cross-sectional side view of the process of manufacturing the display device 1 according to this embodiment, particularly the process of forming the base layer 51 and the first common layer 31, which will be described later.

[0088] The manufacturing method of the display device 1 according to this embodiment is performed in the same manner as the manufacturing method of the display device 1 according to the previous embodiment from step S1 to step S3. In the manufacturing method of the display device 1 according to this embodiment, after step S3, a base layer 51 is formed (step S8).

[0089] The base layer 51 may be formed by using the above-described vapor deposition apparatus 4, for example, using a vapor deposition mask having openings at positions overlapping with multiple subpixels in a plan view of the substrate 3, such as a position overlapping with the display area DA. In other words, the base layer 51 is formed by a vacuum vapor deposition method using a common vapor deposition mask having openings at positions overlapping with all of the red subpixel RSP, green subpixel GSP, and blue subpixel BSP in a plan view of the substrate 3. Therefore, the formation of the base layer 51 includes the vapor deposition of a part of the first hole transport layer 22R, a part of the second hole transport layer 22G, and a part of the third hole transport layer 22B.

[0090] 11, in forming the base layer 51, the touch plate TP and the magnet MG may be disposed on the opposite side of the substrate 3 from the anodes. In forming the base layer 51, the distance between the magnet MG and the touch plate TP may be a distance D2.

[0091] 11 , the first common layer 31 is formed by the same method as in step S4 described above, in other words, by vacuum deposition using the first deposition mask M1. As a result, the first common layer 31 is formed on the base layer 51. By performing the same method as in step S5 described above from step S4 onwards, the manufacture of the display device 1 according to this embodiment is completed.

[0092] In the manufacturing method of the display device 1 according to this embodiment, the base layer 51 is formed by vacuum deposition using a common deposition mask having openings at positions that overlap with multiple subpixels in a plan view of the substrate 3. Therefore, forming the base layer 51 does not require deposition using a deposition mask that has openings only at positions that correspond to specific subpixels, and precise alignment of the installation position of the deposition mask is not required. Therefore, the manufacturing method of the display device 1 according to this embodiment makes it possible to more precisely adjust the optical path length of the cavity of each light-emitting element while reducing the complexity of the manufacturing method.

[0093] In this embodiment, the base layer 51 is located in common with the red subpixel RSP, the green subpixel GSP, and the blue subpixel BSP, but this is not limiting. For example, the base layer 51 may be located only in the red subpixel RSP and the green subpixel GSP or the blue subpixel BSP. In this case, the formation of the base layer 51 includes vapor deposition of a part of the first hole transport layer 22R and a part of the second hole transport layer 22G or a part of the third hole transport layer 22B.

[0094] 12 is a schematic side cross-sectional view of a display device 1 according to this embodiment. The display device 1 according to this embodiment has the same configuration as the display device 1 according to embodiment 1, except that the red light emitting element 2R has a first individual layer 61 between the first anode 21R and the first common layer 31.

[0095] The first individual layers 61 are formed in the shape of islands in the red subpixels RSP and are partitioned by, for example, banks BK. The first individual layers 61 include, for example, the hole transport material described above, and in particular may include the same material as the first common layer 31. Therefore, in this embodiment, the red light emitting element 2R includes, as a first hole transport layer 22R, a portion of the first common layer 31 located in the red subpixel RSP and the first individual layers 61.

[0096] A method for manufacturing the display device 1 according to this embodiment will be described with reference to Fig. 13 and Fig. 14. Fig. 13 is a flowchart of the method for manufacturing the display device 1 according to this embodiment. Fig. 14 is a side cross-sectional view showing the steps of the method for manufacturing the display device 1 according to this embodiment, particularly the steps of forming a first individual layer 61 and forming a first common layer 31, which will be described later.

[0097] The manufacturing method of the display device 1 according to this embodiment is carried out in the same manner as the manufacturing method of the display device 1 according to the previous embodiment from step S1 to step S3. In the manufacturing method of the display device 1 according to this embodiment, after step S3, a first individual layer 61 is formed (step S9).

[0098] In this embodiment, an example in which the first individual layer 61 is formed using the above-described vapor deposition apparatus 4 will be described. In forming the first individual layer 61, first, the material for the first individual layer 61 is stored as a vapor deposition material in the crucible 42 of the vapor deposition apparatus 4. Next, the substrate 3 on which the anodes and banks BK have been formed is stored in the chamber 41 so that the anodes are located closer to the crucible 42 than the substrate 3, and the chamber 41 is evacuated to a substantial vacuum. Next, as shown in step S9 of FIG. 14 , the above-described first vapor deposition mask M1 is placed closer to the anodes than the substrate 3.

[0099] However, in forming the first individual layer 61, in other words, in step S9, the first vapor deposition mask M1 is brought into contact with the surface of the bank BK on the side of the crucible 42. If the bank BK has a mask spacer, in step S9 the first vapor deposition mask M1 may be brought into contact with the mask spacer, thereby bringing the first vapor deposition mask M1 into contact with the bank BK.

[0100] For this reason, in step S9, no gap is formed between the first vapor deposition mask M1 and the bank BK. Therefore, the vapor deposition material emitted from the crucible 42 does not reach the green subpixel GSP or the blue subpixel BSP from the opening M11 of the first vapor deposition mask M1. Therefore, in step S9, the vapor deposition material reaches only the red subpixel RSP that overlaps with the opening M11 in a plan view of the substrate 3. Therefore, in step S9, the first individual layer 61 is formed only in the red subpixel RSP.

[0101] Also in step S9, the touch plate TP and magnet MG may be disposed on the opposite side of the substrate 3 from the anodes. However, in step S9, the distance between the magnet MG and the touch plate TP may be the distance D2 described above, which is longer than the distance D1 described above.

[0102] In step S9, as in step S5, the first deposition mask M1 abuts against the bank BK, and therefore the distance between the first deposition mask M1 and the substrate 3 in step S9 is shorter than the distance between the first deposition mask M1 and the substrate 3 in step S4. Therefore, in step S9, by setting the distance between the magnet MG and the touch plate TP to distance D2, it is possible to prevent the magnet MG from attracting the first deposition mask M1 too strongly, thereby reducing distortion of the first deposition mask M1.

[0103] 14, the first common layer 31 is formed by the same method as in step S4 described above, in other words, by vacuum deposition using the first deposition mask M1. As described above, in step S4, the first deposition mask M1 is positioned away from the bank BK. By performing the same method as in step S5 described above from step S4 onwards, the manufacture of the display device 1 according to this embodiment is completed.

[0104] In this embodiment, step S9 and step S4 form the first hole transport layer 22R, which includes the first individual layer 61 and a portion of the first common layer 31. For example, the vapor deposition in step S9, in which the first individual layer 61, which is a portion of the first hole transport layer 22R, is deposited while the first vapor deposition mask M1 is in contact with the bank BK, is referred to as the first vapor deposition. Also, the vapor deposition in step S4, in which the first common layer 31, which is a portion of the first hole transport layer 22R and at least a portion of the second hole transport layer 22G and the third hole transport layer 22B, is deposited while the first vapor deposition mask M1 is separated from the bank BK, is referred to as the second vapor deposition.

[0105] The manufacturing method for the display device 1 according to this embodiment performs the first and second vapor deposition processes described above. As a result, this method can form at least a portion of each of the first hole transport layer 22R, the second hole transport layer 22G, and the third hole transport layer 22B in the same chamber 41 simply by changing the position of the first vapor deposition mask M1 and the vapor deposition material. In other words, this method can form at least a portion of each hole transport layer without changing the chamber 41 that stores the substrate 3. Therefore, the manufacturing method for the display device 1 according to this embodiment further simplifies the process of forming each hole transport layer.

[0106] In particular, when the first common layer 31 and the first individual layer 61 are made of the same material, the first vapor deposition and the second vapor deposition can be performed consecutively by simply changing the position of the first vapor deposition mask M1 from the bank BK, in other words, without changing the vapor deposition material. Therefore, the manufacturing method of the display device 1 according to this embodiment further simplifies the process of forming each hole transport layer.

[0107] When the first vapor deposition and the second vapor deposition are performed in the same chamber 41, the vapor deposition apparatus 4 may be controlled to perform the first vapor deposition while moving the crucible 42 in the first direction T1 and the second vapor deposition while moving the crucible 42 in the second direction T2. ​​This eliminates the need to perform the first vapor deposition while moving the crucible 42 in the first direction T1, then move the crucible 42 in the second direction T2, and then perform the second vapor deposition while moving the crucible 42 in the first direction T1 again. Therefore, the method can perform vapor deposition over a wider range from the first end 3A to the second end 2B of the substrate 3 in a plan view while simplifying or streamlining control of the movement of the crucible 42 during the first vapor deposition and the second vapor deposition. In addition, in the above method, by individually controlling the movement speed of the crucible 42 in the first direction T1 and the movement speed of the crucible 42 in the second direction T2, the film thickness of the first individual layer 61 and the film thickness of the first common layer 31 can be controlled more simply or more precisely.

[0108] 15 is a schematic side cross-sectional view of a display device 1 according to this embodiment. The display device 1 according to this embodiment has the same configuration as the display device 1 according to embodiment 1, except that it includes a second common layer 32 between the first common layer 31 and the light-emitting layer of each light-emitting element. The second common layer 32 is also located between the first common layer 31 on the bank BK and the electron transport layer 24. In other words, the second common layer 32 is formed in common to a plurality of sub-pixels.

[0109] The second common layer 32 includes, for example, the hole transport material described above, and in particular may include the same material as the first common layer 31. Thus, in this embodiment, the red light-emitting element 2R includes, as a first hole transport layer 22R, portions of the first common layer 31 and the second common layer 32 that are located in the red subpixel RSP. In addition, in this embodiment, the green light-emitting element 2G includes, as a second hole transport layer 22G, portions of the first common layer 31 and the second common layer 32 that are located in the green subpixel GSP. In addition, in this embodiment, the blue light-emitting element 2B includes, as a third hole transport layer 22B, portions of the first common layer 31 and the second common layer 32 that are located in the blue subpixel BSP.

[0110] A method for manufacturing the display device 1 according to this embodiment will be described with reference to Fig. 13 and Fig. 14. Fig. 13 is a flowchart of the method for manufacturing the display device 1 according to this embodiment. Fig. 14 is a side cross-sectional view showing the steps of the method for manufacturing the display device 1 according to this embodiment, particularly the steps of forming a first individual layer 61 and forming a first common layer 31, which will be described later.

[0111] The manufacturing method of the display device 1 according to this embodiment is performed from step S1 to step S4 in the same manner as the manufacturing method of the display device 1 according to embodiment 1. In the manufacturing method of the display device 1 according to this embodiment, after step S4, the second common layer 32 is formed (step S10).

[0112] In forming the second common layer 32, first, the material for the second common layer 32 is placed as a vapor deposition material in the crucible 42 of the vapor deposition device 4. Next, the substrate 3 on which the anodes, banks BK, and first common layer 31 have been formed is placed in the chamber 41 so that the anodes are located closer to the crucible 42 than the substrate 3, and the chamber 41 is evacuated to a substantial vacuum. Next, as shown in step S10 of FIG. 17 , a second vapor deposition mask M2 is placed closer to the anodes than the substrate 3.

[0113] The second vapor deposition mask M2 is a vapor deposition mask that has openings M21 at positions overlapping with the green sub-pixels GSP, in other words, positions overlapping with positions where the second hole transport layers 22G are formed, in a plan view of the substrate 3. The second vapor deposition mask M2 may have the same configuration as the first vapor deposition mask M1 except for the positions of the openings, and may be made of, for example, the same material as the first vapor deposition mask M1.

[0114] 17, the touch plate TP and the magnet MG may be disposed on the opposite side of the substrate 3 from the anodes. In step S10, in other words, in forming the second common layer 32, the distance between the magnet MG and the touch plate TP may be a distance D1.

[0115] 17 , in step S10, in other words, in the formation of the second common layer 32, the second vapor deposition mask M2 is placed below the bank BK, in other words, the second vapor deposition mask M2 is placed away from the bank BK. In this state, in step S10, a vapor deposition material containing the material of the second common layer 32 is released from the crucible 42.

[0116] 17 , in step S10, the vapor deposition material containing the material of the second common layer 32 passes through the opening M21 of the second vapor deposition mask M2 and reaches the green subpixel GSP. As a result, in step S10, a portion of the second common layer 32 located in the green subpixel GSP is formed on the first common layer 31 in the green subpixel GSP.

[0117] In particular, in this embodiment, step S4 and step S10 form the second hole transport layer 22G including the portions of the first common layer 31 and the second common layer 32 that are located in the green subpixel GSP. In other words, step S10 includes vapor deposition of at least a portion of the second hole transport layer 22G using the second vapor deposition mask M2.

[0118] On the other hand, in step S10, a gap is formed between the second vapor deposition mask M2 and the bank BK. Therefore, in step S10, the vapor deposition material emitted from the crucible 42 reaches the red subpixel RSP and the blue subpixel BSP through the openings M21 of the second vapor deposition mask M2.

[0119] Therefore, in step S10, a portion of the second common layer 32 located in the red subpixel RSP is formed on the first common layer 31 in the red subpixel RSP. In addition, in step S10, a portion of the second common layer 32 located in the blue subpixel BSP is formed on the first common layer 31 in the blue subpixel BSP. In other words, in the vapor deposition using the second vapor deposition mask M2 according to this embodiment, at least a portion of the first hole transport layer 22R and at least a portion of the third hole transport layer 22B are formed.

[0120] Fig. 18 is a schematic diagram illustrating the film formation ranges of the first common layer 31 and the second common layer 32. As with Fig. 7 , Fig. 18 indicates by solid lines the positions of parts of the red subpixel RSP, the green subpixel GSP, and the blue subpixel BSP in a plan view of the substrate 3. Fig. 18 also indicates by dotted lines the positions of parts of the openings M11 of the first vapor deposition mask M1 and parts of the second vapor deposition mask M2 in a plan view of the substrate 3. Furthermore, Fig. 18 indicates by dashed-dotted lines the formation positions of the first common layer 31 and the second common layer 32 formed by the vapor deposition material that has passed through the openings M11 and the openings M21 shown in Fig. 18.

[0121] 7 , the first common layer 31 formed by the vapor deposition material passing through the opening M11 overlapping one red subpixel RSP in a plan view of the substrate 3 is also formed on the green subpixels GSP and blue subpixels BSP surrounding the red subpixel RSP. Furthermore, as shown in FIG. 18 , the second common layer 32 formed by the vapor deposition material passing through the opening M21 overlapping one green subpixel GSP in a plan view of the substrate 3 is also formed on the red subpixels RSP and blue subpixels BSP surrounding the green subpixel GSP.

[0122] As described above, by forming the first common layer 31 in step S4 and the second common layer 32 in step S10, the first hole transport layer 22R, the second hole transport layer 22G, and the third hole transport layer 22B are formed.

[0123] However, the second vapor deposition mask M2 shields the crucible 42 from the red subpixel RSP and the blue subpixel BSP in a plan view of the substrate 3. Therefore, the film thickness of the portion of the second common layer 32 that is formed in the green subpixel GSP and overlaps with the opening M21 of the second vapor deposition mask M2 in a plan view of the substrate 3 is larger than the film thickness of the portion of the second common layer 32 that is formed in the red subpixel RSP and the blue subpixel BSP.

[0124] From step S10 onwards, the same method as from step S5 onwards described above is carried out, thereby completing the manufacture of the display device 1 according to this embodiment.

[0125] In this embodiment, deposition is performed using the first deposition mask M1 in step S4, while deposition is performed using the second deposition mask M2, which has an opening at a position different from that of the first deposition mask M1, in step S10. Therefore, according to the above method, the film thickness of each portion of the first common layer 31 formed in step S4 and the film thickness of each portion of the second common layer 32 formed in step S10 can be individually controlled, thereby making it possible to more precisely control the film thickness of each hole transport layer.

[0126] For example, suppose that the film thickness of the portion of the first common layer 31 located in the red subpixel RSP is smaller than the film thickness of the portion of the second common layer 32 located in the green subpixel GSP. In this case, by using the above method, the film thickness of the first hole transport layer 22R can be made larger than the film thickness of the second hole transport layer 22G, and the film thickness of the second hole transport layer 22G can be made larger than the film thickness of the third hole transport layer 22B.

[0127] In this embodiment, the entire third hole transport layer 22B is formed by step S4, i.e., vapor deposition using the first vapor deposition mask M1, and step S10, i.e., vapor deposition using the second vapor deposition mask M2. This eliminates the need to perform a vapor deposition step for forming, for example, only a portion of the third hole transport layer 22B, further simplifying the process of forming each hole transport layer.

[0128] Generally, in vacuum deposition, when controlling the thickness of a layer consisting of multiple deposited films with different thicknesses, the thickness of the layer can be controlled more precisely by depositing the thicker deposited film first and then the thinner deposited film. In this embodiment, step S4, i.e., deposition using the first deposition mask M1, is followed by step S10, i.e., deposition using the second deposition mask M2. As a result, in this embodiment, the first common layer 31 in the first hole transport layer 22R, which is thicker than the second hole transport layer 22G, can be formed to be thicker than the second common layer 32. Therefore, this configuration allows for more precise control of the thickness of the first hole transport layer 22R in steps S4 and S10.

[0129] 19 is a schematic side cross-sectional view of a display device 1 according to this embodiment. The display device 1 according to this embodiment has the same configuration as the display device 1 according to the previous embodiment, except that the red light emitting element 2R includes the first individual layer 61 described above, and the green light emitting element 2G includes the second individual layer 62 between the first common layer 31 and the second common layer 32.

[0130] The second individual layers 62 are formed in an island shape in the green subpixel GSP and are partitioned by, for example, banks BK. The second individual layers 62 include, for example, the hole transport material described above, and may particularly include the same material as any of the first common layer 31, the second common layer 32, and the first individual layers 61. Therefore, in this embodiment, the green light-emitting element 2G includes, as a second hole transport layer 22G, portions of the first common layer 31 and the second common layer 32 that are located in the green subpixel GSP and the second individual layers 62. Note that, in this embodiment, the red light-emitting element 2R includes, as a first hole transport layer 22R, portions of the first common layer 31 and the second common layer 32 that are located in the red subpixel RSP and the first individual layers 61.

[0131] A method for manufacturing the display device 1 according to this embodiment will be described with reference to Fig. 20 and Fig. 21. Fig. 20 is a flowchart of the method for manufacturing the display device 1 according to this embodiment. Fig. 21 is a side cross-sectional view showing the steps of the method for manufacturing the display device 1 according to this embodiment, particularly the steps of forming the second individual layer 62 and the second common layer 32, which will be described later.

[0132] The manufacturing method of the display device 1 according to this embodiment is carried out in the same manner as the manufacturing method of the display device 1 according to the previous embodiment from step S1 to step S4. In the manufacturing method of the display device 1 according to this embodiment, after step S4, the second individual layer 62 is formed (step S11).

[0133] In this embodiment, an example in which the second individual layer 62 is formed using the above-described vapor deposition apparatus 4 will be described. In forming the second individual layer 62, first, the material for the second individual layer 62 is stored as a vapor deposition material in the crucible 42 of the vapor deposition apparatus 4. Next, the substrate 3 on which the anodes, bank BK, first individual layer 61, and first common layer 31 have been formed is stored in the chamber 41 so that the anodes are located closer to the crucible 42 than the substrate 3, and the chamber 41 is evacuated to a substantial vacuum. Next, as shown in step S11 of FIG. 21 , the above-described second vapor deposition mask M2 is placed closer to the anodes than the substrate 3.

[0134] However, in forming the second individual layer 62, in other words, in step S11, the second vapor deposition mask M2 is brought into contact with the surface of the bank BK on the side of the crucible 42. If the bank BK has a mask spacer, in step S11 the second vapor deposition mask M2 may be brought into contact with the bank BK by bringing the second vapor deposition mask M2 into contact with the mask spacer.

[0135] For this reason, in step S11, no gap is formed between the second vapor deposition mask M2 and the bank BK. Therefore, the vapor deposition material emitted from the crucible 42 does not reach the red subpixel RSP or the blue subpixel BSP from the opening M21 of the second vapor deposition mask M2. Therefore, in step S11, the vapor deposition material reaches only the green subpixel GSP that overlaps with the opening M21 in a plan view of the substrate 3. Therefore, in step S11, the second individual layer 62 is formed only in the green subpixel GSP.

[0136] Also in step S11, the touch plate TP and magnet MG may be disposed on the opposite side of the substrate 3 from the anodes. In step S11, the distance between the magnet MG and the touch plate TP may be the distance D2 described above.

[0137] In step S11, the second deposition mask M2 comes into contact with the bank BK, as in steps S5 and S9. Therefore, the distance between the second deposition mask M2 and the substrate 3 in step S11 is shorter than the distance between the second deposition mask M2 and the substrate 3 in step S10. Therefore, in step S11, by setting the distance between the magnet MG and the touch plate TP to distance D2, it is possible to prevent the magnet MG from attracting the second deposition mask M2 too strongly, thereby reducing distortion of the second deposition mask M2.

[0138] 21, the second common layer 32 is formed by the same method as in step S10 described above, in other words, by vacuum deposition using the second deposition mask M2. As described above, in step S10, the second deposition mask M2 is positioned away from the bank BK. By performing the same method as in step S5 described above from step S10 onwards, the manufacture of the display device 1 according to this embodiment is completed.

[0139] In this embodiment, the second hole transport layer 22G including a part of the first common layer 31, the second individual layer 62, and a part of the second common layer 32 is formed by steps S4, S11, and S10. For example, the deposition in step S11 of depositing the second individual layer 62, which is a part of the second hole transport layer 22G, with the second deposition mask M2 in contact with the bank BK is referred to as the third deposition. Also, the deposition in step S10 of depositing the second common layer 32, which is a part of the second hole transport layer 22G and at least a part of the first hole transport layer 22R and the third hole transport layer 22B, with the second deposition mask M2 separated from the bank BK is referred to as the fourth deposition.

[0140] The manufacturing method for the display device 1 according to this embodiment performs the third and fourth vapor depositions described above. As a result, this method can form at least a portion of each of the first hole transport layer 22R, the second hole transport layer 22G, and the third hole transport layer 22B in the same chamber 41 simply by changing the position of the second vapor deposition mask M2 and the vapor deposition material. In other words, the above method can form at least a portion of each hole transport layer without changing the chamber 41 that stores the substrate 3. Therefore, the manufacturing method for the display device 1 according to this embodiment further simplifies the process of forming each hole transport layer.

[0141] In particular, when the second common layer 32 and the second individual layer 62 are made of the same material, the third vapor deposition and the fourth vapor deposition can be performed successively by simply changing the position of the second vapor deposition mask M2 from the bank KB, in other words, without changing the vapor deposition material. Therefore, the manufacturing method of the display device 1 according to this embodiment further simplifies the process of forming each hole transport layer.

[0142] When the third vapor deposition and the fourth vapor deposition are performed in the same chamber 41, in the above method, the vapor deposition apparatus 4 may be controlled so that the third vapor deposition is performed while moving the crucible 42 in the first direction T1, and the fourth vapor deposition is performed while moving the crucible 42 in the second direction T2.

[0143] The present disclosure is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present disclosure. Furthermore, new technical features can be formed by combining the technical means disclosed in each embodiment.

[0144] REFERENCE SIGNS LIST 1 Display device 2B Blue light-emitting element 2G Green light-emitting element 2R Red light-emitting element 3 Substrate 21R First anode 21G Second anode 21B Third anode 22R First hole transport layer (first charge transport layer) 22G Second hole transport layer (second charge transport layer) 22B Third hole transport layer (third charge transport layer) 23R Red light-emitting layer (first light-emitting layer) 23G Green light-emitting layer (second light-emitting layer) 23B Blue light-emitting layer (third light-emitting layer) 25 Cathode 42 Crucible M1 First vapor deposition mask M2 Second vapor deposition mask T1 First direction T2 Second direction BK Bank TP Touch plate MG Magnet

Claims

1. A method for manufacturing a display device comprising a substrate, a first light-emitting element on the substrate, and a second light-emitting element on the substrate that emits light different from that of the first light-emitting element, wherein the first light-emitting element comprises a first anode and a first cathode, one of which is a first reflective electrode and facing each other, a first light-emitting layer between the first anode and the first cathode, and a first charge transport layer between the first reflective electrode and the first light-emitting layer, and the second light-emitting element comprises a second anode and a second cathode, one of which is a second reflective electrode and facing each other, a second light-emitting layer between the second anode and the second cathode, and a second charge transport layer between the second reflective electrode and the second light-emitting layer, the method comprising vapor-depositing at least a portion of the first charge transport layer using a first vapor deposition mask having an opening in a position that overlaps with the formation position of the first light-emitting element in a planar view of the substrate, and depositing at least a portion of the second charge transport layer during the vapor deposition using the first vapor deposition mask.

2. A method for manufacturing a display device as described in claim 1, wherein the central wavelength of the light emitted by the first light-emitting element is longer than the central wavelength of the light emitted by the second light-emitting element, and the film thickness of the first charge transport layer is greater than the film thickness of the second charge transport layer.

3. The method for manufacturing a display device according to claim 2, wherein the first light-emitting element is a red light-emitting element and the second light-emitting element is a green light-emitting element.

4. A method for manufacturing a display device described in any one of claims 1 to 3, wherein the first reflective electrode is the first anode, the second reflective electrode is the second anode, the first charge transport layer is the first hole transport layer of the first light-emitting element, and the second charge transport layer is the second hole transport layer of the second light-emitting element.

5. A method for manufacturing a display device described in any one of claims 1 to 4, comprising vapor deposition of a portion of the first charge transport layer and a portion of the second charge transport layer using a common vapor deposition mask having openings at positions that overlap both the formation position of the first light-emitting element and the formation position of the second light-emitting element in a planar view of the substrate.

6. A method for manufacturing a display device according to any one of claims 1 to 5, wherein the display device comprises a bank on the substrate that separates at least the first charge transport layer and the second charge transport layer, and the vapor deposition using the first vapor deposition mask includes a first vapor deposition for depositing a portion of the first charge transport layer with the first vapor deposition mask in contact with the bank, and a second vapor deposition for depositing a portion of the first charge transport layer and at least a portion of the second charge transport layer with the first vapor deposition mask separated from the bank.

7. A method for manufacturing a display device as described in claim 6, wherein, during vapor deposition using the first vapor deposition mask, a touch plate is abutted against the side of the substrate opposite the first vapor deposition mask, and a magnet that attracts the first vapor deposition mask is placed on the side opposite the substrate from the touch plate, and the distance between the magnet and the touch plate during the second vapor deposition is made shorter than the distance between the magnet and the touch plate during the first vapor deposition.

8. A method for manufacturing a display device according to claim 6 or 7, wherein, in vapor deposition using the first vapor deposition mask, a crucible containing a vapor deposition material is placed closer to the first vapor deposition mask than the substrate, and the vapor deposition material is released from the crucible while moving the crucible in a planar view of the substrate to perform vapor deposition; in the first vapor deposition, vapor deposition is performed while moving the crucible in a first direction that is a direction from a first end that is one end of the substrate in a planar view of the substrate to a second end that is the other end opposite the first end; and in the second vapor deposition, vapor deposition is performed while moving the crucible in a second direction that is a direction opposite to the first direction.

9. A method for manufacturing a display device according to any one of claims 1 to 8, comprising depositing at least a portion of the second charge transport layer using a second deposition mask having an opening at a position overlapping with a position where the second light-emitting element is formed in a plan view of the substrate, and depositing at least a portion of the first charge transport layer during deposition using the second deposition mask.

10. A method for manufacturing a display device according to any one of claims 1 to 5, wherein the display device comprises a third light-emitting element on the substrate that emits light different from both the first light-emitting element and the second light-emitting element, the third light-emitting element comprising a third anode and a third cathode, one of which is a third reflective electrode and which face each other, a third light-emitting layer between the third anode and the third cathode, and a third charge transport layer between the third reflective electrode and the third light-emitting layer, and wherein at least a portion of the second charge transport layer and at least a portion of the third charge transport layer are formed by vapor deposition using the first vapor deposition mask.

11. A method for manufacturing a display device as described in claim 10, wherein the central wavelength of the light emitted by the second light-emitting element is longer than the central wavelength of the light emitted by the third light-emitting element, and the film thickness of the second charge transport layer is greater than the film thickness of the third charge transport layer.

12. The method for manufacturing a display device according to claim 11, wherein the third light-emitting element is a blue light-emitting element.

13. A method for manufacturing a display device according to any one of claims 10 to 12, wherein the third reflective electrode is the third anode, and the third charge transport layer is the third hole transport layer of the third light-emitting element.

14. A method for manufacturing a display device described in any one of claims 10 to 13, wherein the display device comprises a bank on the substrate that separates at least the first charge transport layer, the second charge transport layer, and the third charge transport layer, and the vapor deposition using the first vapor deposition mask includes a first vapor deposition for depositing a portion of the first charge transport layer with the first vapor deposition mask in contact with the bank, and a second vapor deposition for depositing a portion of the first charge transport layer, at least a portion of the second charge transport layer, and at least a portion of the third charge transport layer with the first vapor deposition mask separated from the bank.

15. A method for manufacturing a display device described in any one of claims 10 to 13, comprising vapor deposition of at least a portion of the second charge transport layer using a second vapor deposition mask having an opening at a position overlapping the formation position of the second light-emitting element in a planar view of the substrate, and depositing at least a portion of the first charge transport layer and a portion of the third charge transport layer during vapor deposition using the second vapor deposition mask.

16. The method for manufacturing a display device according to claim 15, wherein the third charge transport layer is entirely formed by vapor deposition using the first vapor deposition mask and vapor deposition using the second vapor deposition mask.

17. The method for manufacturing a display device according to claim 15 or 16, wherein deposition using the second deposition mask is carried out after deposition using the first deposition mask.

18. A method for manufacturing a display device described in any one of claims 15 to 17, wherein the display device comprises a bank on the substrate that separates at least the first charge transport layer, the second charge transport layer, and the third charge transport layer, and the vapor deposition using the second vapor deposition mask includes a third vapor deposition in which a portion of the second charge transport layer is deposited with the second vapor deposition mask in contact with the bank, and a fourth vapor deposition in which a portion of the second charge transport layer, at least a portion of the first charge transport layer, and at least a portion of the third charge transport layer are deposited with the second vapor deposition mask separated from the bank.

19. A display device comprising: a substrate; a first light-emitting element on the substrate; a second light-emitting element on the substrate that emits light different from that of the first light-emitting element; and a bank located on the substrate and between the first light-emitting element and the second light-emitting element in a planar view of the substrate, wherein the first light-emitting element comprises a first anode and a first cathode, one of which is a first reflective electrode and facing each other, a first light-emitting layer between the first anode and the first cathode, and a first charge transport layer between the first reflective electrode and the first light-emitting layer, and the second light-emitting element comprises a second anode and a second cathode, one of which is a second reflective electrode and facing each other, a second light-emitting layer between the second anode and the second cathode, and a second charge transport layer between the second reflective electrode and the second light-emitting layer, and the bank separates at least the first charge transport layer and the second charge transport layer, and a layer containing a material contained in the first charge transport layer is located on a side of the bank adjacent to the second light-emitting element.

20. The display device of claim 19, further comprising a third light-emitting element on the substrate that emits light different from both the first light-emitting element and the second light-emitting element, the third light-emitting element comprising a third anode and a third cathode, one of which is a third reflective electrode and which face each other, a third light-emitting layer between the third anode and the third cathode, and a third charge transport layer between the third reflective electrode and the third light-emitting layer, the bank separating at least the first charge transport layer, the second charge transport layer, and the third charge transport layer, and a layer containing at least one of a material contained in the first charge transport layer and a material contained in the second charge transport layer is located on a side of the bank adjacent to the third light-emitting element.

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