Light-emitting device, manufacturing method thereof, and image forming apparatus

Abstract

To provide a technique advantageous for reducing cost of manufacture of a light-emitting device having a moisture resistant ring structure.SOLUTION: A light-emitting device comprises a rectangular substrate including first and second sides, which are parallel in a first direction, and third and fourth sides which are parallel in a second direction orthogonal to the first direction. The light-emitting device comprises: a light-emitting element array consisting of a plurality of light-emitting elements disposed on the rectangular substrate; a pad disposed on the rectangular substrate so as to be positioned between the first side and the light-emitting element array; and a moisture resistant ring structure disposed in the rectangular substrate so as to suppress infiltration of moisture to the light-emitting element array and the pad. The moisture resistant ring structure includes a moisture resistant wall disposed between the light-emitting element array and the first side. A shortest distance between the light-emitting element array and the moisture resistant wall in the second direction is smaller than a distance between the light-emitting element array and the moisture resistant wall on a virtual straight line which is parallel in the second direction and passes the light-emitting element array and the pad.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to a light emitting device, a manufacturing method thereof, and an image forming apparatus. [Background technology]

[0002] There is a light-emitting device in which multiple functional layers, such as a hole injection layer, a hole transport layer, a light-emitting layer, an electron transport layer, and an electron injection layer, are formed in a deposition process using a deposition mask. The deposition mask has multiple openings, and in the deposition process, materials for the functional layers can be deposited on a substrate through the multiple openings. Meanwhile, a moisture-resistant ring can be provided in the light-emitting device to prevent moisture from penetrating into a light-emitting element having multiple functional layers. Patent Document 1 describes a light-emitting device having a rectangular guard ring. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-29070 A Summary of the Invention [Problem to be solved by the invention]

[0004] The deposition mask may have protrusions called ribs or the like to maintain a constant gap between the pattern portion of the deposition mask and the material substrate. In the deposition process, the deposition mask may be arranged so that the protrusions come into contact with the contact-permitted area (area where contact with the protrusions is permitted) of the material substrate. If the contact-permitted area is arranged outside the moisture-resistant ring, adjacent light-emitting devices on the material substrate are arranged across the contact-permitted area, limiting the number of light-emitting devices that can be obtained from one substrate. This may result in an increase in the manufacturing cost of the light-emitting devices.

[0005] An object of the present invention is to provide an advantageous technique for reducing the manufacturing costs of a light-emitting device having a moisture-resistant ring structure. [Means for solving the problem]

[0006] One aspect of the present invention relates to a light-emitting device having a rectangular substrate having a first side and a second side parallel to a first direction and a third side and a fourth side parallel to a second direction perpendicular to the first direction, the light-emitting device comprising: a light-emitting element array composed of a plurality of light-emitting elements arranged on the rectangular substrate; a pad arranged on the rectangular substrate so as to be located between the first side and the light-emitting element array; and a moisture-resistant ring structure arranged on the rectangular substrate so as to prevent moisture from penetrating into the light-emitting element array and the pad, the moisture-resistant ring structure including a moisture-resistant wall arranged between the light-emitting element array and the first side, and a shortest distance between the light-emitting element array and the moisture-resistant wall in the second direction is smaller than a distance between the light-emitting element array and the moisture-resistant wall on a virtual straight line parallel to the second direction and passing through the light-emitting element array and the pad. Effect of the Invention

[0007] According to the present invention, an advantageous technique is provided for reducing the manufacturing cost of a light-emitting device having a moisture-resistant ring structure. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a plan view diagrammatically showing a plurality of light emitting devices in the process of being manufactured, which are arranged on a material substrate. [Diagram 2] FIG. 4 is a plan view illustrating an example of a deposition mask. [Diagram 3] FIG. 3 is an enlarged plan view of a portion of the deposition mask in FIG. 2. [Figure 4] FIG. 2 is a cross-sectional view illustrating a material substrate and a deposition mask arranged on top of each other. [Diagram 5] FIG. 11 is a plan view illustrating another deposition mask. [Figure 6] FIG. 1 is a plan view illustrating a configuration of a light emitting device according to a first embodiment. [Figure 7] FIG. 7 is a cross-sectional view showing a schematic cross section taken along line BB' in FIG. [Figure 8]FIG. 7 is a cross-sectional view showing a schematic cross section taken along the line CC' in FIG. 6. [Figure 9] FIG. 1 is a plan view illustrating a configuration of a light emitting device according to a comparative example. [Figure 10] FIG. 11 is a plan view illustrating a configuration of a light emitting device according to a second embodiment. [Figure 11] FIG. 13 is a plan view illustrating a configuration of a light emitting device according to a third embodiment. [Figure 12] FIG. 1 is a diagram illustrating a configuration of an image forming apparatus according to an embodiment. [Figure 13] FIG. 1 is a diagram showing an example of an array of a plurality of light emitting devices. [Figure 14] 10A to 10C are diagrams illustrating modified examples of the light emitting devices according to the first to third embodiments. [Figure 15] FIG. 7 is a cross-sectional view showing a schematic cross section taken along line DD' of FIG. 6. [Figure 16] 13 shows the arrangement of substrates and deposition masks in a light emitting device according to a fourth embodiment. [Figure 17] FIG. 13 is a cross-sectional view of an example of a light emitting device according to a fourth embodiment. [Figure 18] FIG. 13 is a plan view of an example of a light emitting device according to a fourth embodiment. [Figure 19] FIG. 19 is a cross-sectional view of an example taken along the E-E' plane in FIG. [Figure 20] FIG. 13 is a plan view of an example of a light emitting device according to a fifth embodiment. [Figure 21] FIG. 13 is a plan view of an example of a light emitting device according to a sixth embodiment. [Figure 22] FIG. 22 is a cross-sectional view of an example taken along the plane FF' in FIG. 21. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, the embodiments will be described in detail with reference to the attached drawings. Note that the following embodiments do not limit the invention according to the claims. Although the embodiments describe a number of features, not all of these features are essential to the invention, and the features may be combined in any manner. Furthermore, in the attached drawings, the same reference numbers are used for the same or similar configurations, and duplicated descriptions are omitted.

[0010] The structure of the light emitting device 2 of the first embodiment and a method for manufacturing the same will be described below by way of example. The numerical values, shapes, materials, components, arrangements and connection forms of the components described herein do not limit the scope of disclosure unless expressly stated to be limited. The light emitting device 2 can be manufactured by processing a material substrate such as a silicon wafer. In this specification, in order to prevent the description from becoming complicated, a light emitting device in the middle of manufacture may also be described as a light emitting device. In addition, in this specification and the drawings, directions are described according to the XYZ coordinate system. Here, the XYZ coordinate system is defined so that the main surface of the material substrate or the light emitting device is parallel to the XY plane. In the following, for convenience of description, the X direction is described as the first direction and the Y direction is described as the second direction perpendicular to the first direction, but for example, the Y direction may be the first direction and the X direction as the second direction. In the following description, a plan view is synonymous with a plan view and also with an orthogonal projection onto the XY plane.

[0011] FIG. 1 shows a schematic diagram of a plurality of light-emitting devices 2 in the process of being manufactured, which are arranged on a material substrate 1 such as a silicon wafer. Each light-emitting device 2 is provided with a light-emitting element array 3, or the light-emitting element array 3 is defined. The definition of the light-emitting element array 3 means that an area in which the light-emitting element array 3 is to be formed has been defined, but the light-emitting element array 3 has not yet been completed. The completed light-emitting element array 3 has a plurality of light-emitting elements. The light-emitting element array 3 or the plurality of light-emitting elements may include a plurality of first electrodes that can be individually controlled, an organic film disposed on the plurality of first electrodes, and a second electrode disposed on the organic film. In one example, the organic film and the second electrode may be shared by the plurality of light-emitting elements. The organic film may be composed of a plurality of functional layers. Each of the plurality of functional layers may be composed of an organic material. In another aspect, each of the plurality of light-emitting elements may include a hole injection layer, a hole transport layer, an organic light-emitting layer, an electron transport layer, and an electron injection layer.

[0012] FIG. 2 shows a schematic diagram of a deposition mask 4 for manufacturing a plurality of light-emitting devices 2. The dotted line or circle in FIG. 2 indicates the region where the material substrate 1 is disposed. FIG. 3 shows an enlarged view of a portion of FIG. 2. Here, the deposition mask 4 shown in FIG. 2 and FIG. 3 can be used to form a plurality of organic films on the light-emitting element array 3 of each light-emitting device 2 by deposition. FIG. 4 shows a schematic diagram of the material substrate 1 and the deposition mask 4 arranged on top of each other. FIG. 4 corresponds to the A-A' cross section of FIG. 2. The deposition mask 4 has a pattern portion PP having a plurality of rectangular regions RR corresponding to the plurality of light-emitting devices 2, respectively, and a plurality of protrusions 6, and each rectangular substrate region RR can have one opening 5 for forming an organic film. Each rectangular substrate region RR may have a plurality of openings 5. In the deposition process, the material gas discharged from a source of the material gas can be provided to the material substrate 1 through each opening 5.

[0013] The material substrate 1, or the multiple light-emitting devices 2 in the process of being manufactured, have a contact-permitting region 10 which is a region that is permitted to come into contact with the protruding portion 6 of the deposition mask 4. The contact-permitting region 10 can typically be a partial region of the upper surface of a layer laminated on the material substrate 1, but for simplicity, such a region is also expressed here as the contact-permitting region 10 of the material substrate 1. Each light-emitting device 2 in the process of being manufactured can have at least one contact-permitting region 10, and preferably at least two contact-permitting regions 10.

[0014] The deposition mask 4 does not contact the material substrate 1 (and layers laminated on the material substrate 1) except when the protruding portion 6 contacts the corresponding contact allowing region 10. The gap between the material substrate 1 and the pattern portion PP of the deposition mask 4 is defined by contacting the protruding portion 6 of the deposition mask 4 with the contact allowing region 10 of the material substrate 1. This method is advantageous for arranging the material substrate 1 and the pattern portion PP of the deposition mask 4 in close proximity while maintaining an accurate gap between the material substrate 1 and the pattern portion PP of the deposition mask 4. This is useful for suppressing deposition in unnecessary regions and further for miniaturizing each light-emitting device 2. A trace of contact of the protruding portion 6, which is part of the deposition mask 4, in the manufacturing process of the light-emitting device 2 may be formed in the contact allowing region 10. Such a trace may be, for example, a scratch.

[0015] A magnet may be used to fix the deposition mask 4 to the material substrate 1. In this case, the deposition mask 4 may be made of a magnetic material such as Invar. Alternatively, a pressure mechanism that presses the deposition mask 4 against the material substrate 1 may be used to fix the deposition mask 4 to the material substrate 1.

[0016] After an organic film (multiple functional layers) is formed on the light-emitting element array 3 using the deposition mask 4 shown in FIG. 2 and FIG. 3, a second electrode may be formed using the deposition mask 4 shown in FIG. 5. The dotted line or circle in FIG. 5 indicates the region where the material substrate 1 is disposed. The deposition mask 4 has a pattern portion PP having a plurality of rectangular substrate regions RR corresponding to the plurality of light-emitting devices 2, respectively, and a plurality of protrusions 6, and each rectangular substrate region RR may have one opening 5 for forming a second electrode. After the formation of the plurality of second electrodes, a protective film may be formed over the entire region of the material substrate 1 so as to cover the plurality of second electrodes of the material substrate 1. This may suppress the intrusion of moisture into the organic film (multiple functional layers).

[0017] FIG. 6 shows a schematic configuration of one light emitting device 2. The light emitting device 2 has a rectangular substrate RS having a first side S1 and a second side S2 parallel to the X direction (first direction), and a third side S3 and a fourth side S4 parallel to the Y direction (second direction) perpendicular to the X direction (first direction). The rectangular substrate RS is a part of the material substrate 1, more specifically, a part that is chipped by dicing from the material substrate 1. The light emitting device 2 may also include a light emitting element array 3 composed of a plurality of light emitting elements arranged on the rectangular substrate RS, and one or more pads 8 arranged on the rectangular substrate RS so as to be located between the first side S1 and the light emitting element array 3. The light emitting device 2 may also include a moisture-resistant ring structure 70 arranged on the rectangular substrate RS to suppress the intrusion of moisture into the light emitting element array 3 and all the pads 8. The pads may be connected to an external circuit.

[0018] The moisture-resistant ring structure 70 may include a moisture-resistant wall 71 disposed between the light-emitting element array 3 and the first side S1. In FIG. 6, the moisture-resistant wall 71 in the moisture-resistant ring structure 70 is indicated by a thick gray line. The shortest distance between the light-emitting element array 3 and the moisture-resistant wall 71 in the Y direction (second direction) is a distance d1. The distance between the light-emitting element array 3 and the moisture-resistant wall 71 on a virtual straight line VSL that is parallel to the Y direction (second direction) and passes through the light-emitting element array 3 and the pad 8 is a distance d2. In the first embodiment, the distance d1 is smaller than the distance d2. This is advantageous for reducing the distance (spacing) between the light-emitting devices 2 adjacent to each other in the Y direction on the material substrate 1, thereby increasing the number of light-emitting devices 2 that can be formed on the material substrate 1 and reducing the manufacturing cost of the light-emitting devices 2.

[0019] The moisture-resistant ring structure 70 may include a first moisture-resistant ring 7 arranged to surround the light-emitting element array 3 and the pad 8. The moisture-resistant wall 71 may be a part of the first moisture-resistant ring 7. The first moisture-resistant ring 7 may be arranged to surround the entire periphery of the light-emitting element array 3.

[0020] The light emitting device 2 may further include a plurality of contact regions 9 arranged on the rectangular substrate RS so as to receive a signal or potential for driving a plurality of light emitting elements of the light emitting element array 3. The plurality of contact regions 9 may be electrically connected to second electrodes of the plurality of light emitting elements. The moisture-resistant ring structure 70 may be arranged on the rectangular substrate RS so as to suppress the intrusion of moisture into the plurality of contact regions 9 in addition to the light emitting element array 3 and the plurality of pads 8. More specifically, the first moisture-resistant ring 7 of the moisture-resistant ring structure 70 may be arranged on the rectangular substrate RS so as to surround the light emitting element array 3, the plurality of pads 8, and the plurality of contact regions 9. The first moisture-resistant ring 7 may preferably be arranged on the rectangular substrate RS so as to surround the light emitting element array 3, the plurality of pads 8, and the plurality of contact regions 9 all around.

[0021] It is preferable that the dimension in the X direction (first direction) of the smallest rectangle (virtual smallest rectangle) circumscribing the light-emitting element array 3 is greater than the dimension in the Y direction (second direction). For example, the dimension in the X direction (first direction) of the smallest rectangle (virtual smallest rectangle) circumscribing the light-emitting element array 3 can be two or more times, three or more times, or five or more times the dimension in the Y direction (second direction).

[0022] The contact regions 9 may include a first contact region 9a, a second contact region 9b, and a third contact region 9c. The first contact region 9a is disposed between the light-emitting element array 3 and the first side S1, the second contact region 9b is disposed between the light-emitting element array 3 and the third side S3, and the third contact region 9c is disposed between the light-emitting element array 3 and the fourth side S4. In FIG. 6, the reference characters 9a, 9b, and 9c are attached together with the reference character 9 to distinguish the contact regions 9 from one another. In FIG. 6, the reference characters 8a, 8b, 8c, and 8d are attached together with the reference character 8 to distinguish the pads 8 from one another. In one example, the portion of the moisture-resistant wall 71 that defines the shortest distance d1 may be disposed between the first pad 8b on the virtual straight line VSL and the first contact region 9a. The pads 8 may include a second pad 8c disposed on the rectangular substrate RS so as to be located between the first side S1 and the light-emitting element array 3, in addition to the first pad 8b on the virtual straight line VSL. The portion of the moisture resistant wall 71 that defines the shortest distance d1 can be disposed between the first pad 8b and the second pad 8c.

[0023] Fig. 7 shows a schematic cross section taken along line B-B' in Fig. 6. However, in Fig. 7, components arranged below the first electrode 13 of the light-emitting element 19 constituting the light-emitting element array 3 are omitted. The light-emitting element 19 may include the first electrode 13, an organic film 14 arranged on the first electrode 13, and a second electrode 15 arranged on the organic film 14. The organic film 14 may include a plurality of functional layers. The first electrode 13 may be an independent electrode provided for each light-emitting element 19, and the second electrode 15 may be a common electrode provided in common to the plurality of light-emitting elements 19.

[0024] Since the light generated by the light emitting element 19 passes through the second electrode 15 and is emitted from the light emitting device 2, the second electrode 15 is composed of a transparent or semi-transparent layer. Since the second electrode 15 is composed of, for example, a thin film of a metal material, it can have a relatively high wiring resistance. If the light emitting element array 3 has a shape long in the X direction and the contact regions 9 are arranged only in the longitudinal direction of the light emitting element array 3, shading occurs in which the luminance changes with distance from the contact region 9 due to a voltage drop in the second electrode 15. To address this, as exemplified by the contact region 9a in FIG. 6, the number of contact regions 9 according to the longitudinal length of the light emitting element array 3 can be arranged at appropriate positions in the longitudinal direction.

[0025] 8 is a schematic diagram showing a cross section of CC' in FIG. 6. The first moisture-resistant ring 7 may be formed by laminating a contact plug and a metal wiring, for example. The surface of the first moisture-resistant ring 7 is covered with a protective film 16, which prevents moisture from penetrating from the outside of the first moisture-resistant ring 7 to the inside region (including the light-emitting element array 3).

[0026] Fig. 15 is a schematic diagram of a cross section taken along line DD' in Fig. 6. Fig. 15 is a schematic diagram of an example of a light-emitting element 23 and a transistor 20 connected to the light-emitting element 23. The transistor 20 is an example of an active element. The transistor 20 may be a thin-film transistor (TFT).

[0027] The drain 25 and source 24 of the transistor 20 are disposed on the material substrate 1, and the gate 26 of the transistor 20 is disposed on the material substrate 1 via a gate insulating film (not shown).

[0028] There are a plurality of contact plugs 21_1 to 22_4 and a plurality of metal wirings 22_1 to 22_4 that electrically connect the drain 25 of the transistor 20 and the light emitting element 23, and an insulating layer 28 is provided between the wirings. Although the insulating layer 28 is illustrated as a single layer in Fig. 15, the insulating layer 28 may have a laminated structure made up of a plurality of layers.

[0029] The light-emitting element 23 may be composed of a first electrode 13, an organic film 14 having a light-emitting layer, and a second electrode 15. In FIG. 15, the organic film 14 is illustrated as one layer, but the organic film 14 may be composed of multiple layers. In the light-emitting element 23, the second electrode 14 is a transparent electrode, and light from the organic film 14 is extracted to the outside through the second electrode 15. A protective layer 16 is provided on the second electrode 15 to reduce deterioration of the light-emitting element 23. The second electrode 15 of the light-emitting element 23 is shared by multiple light-emitting elements 23 and serves as a common electrode.

[0030] In the light-emitting element array, structural units each composed of a combination of a light-emitting element 23 and a transistor 20 can be repeatedly arranged in the row and column directions. The method of electrical connection between the light-emitting element 23 and the electrodes (source electrode, drain electrode) included in the transistor 20 is not limited to the embodiment shown in Fig. 15. Either the source electrode or the drain electrode of the transistor 20 may be electrically connected to the first electrode 13 of the light-emitting element 23 depending on the polarity of the first electrode 13 of the light-emitting element 23 and the polarity of the transistor 20. In Fig. 15, a transistor is used as the switching element, but other switching elements may be used instead.

[0031] The transistor 20 is not limited to a transistor formed on a single crystal silicon wafer, but may be a thin film transistor having an active layer on an insulating surface of a substrate. Examples of the active layer include non-single crystal silicon such as single crystal silicon, amorphous silicon, and microcrystalline silicon, and non-single crystal oxide semiconductors such as indium zinc oxide and indium gallium zinc oxide.

[0032] Furthermore, the moisture-resistant ring 7 and the protective layer 16 of the light-emitting element 23 are in physical contact with each other, reducing or preventing the penetration of moisture from the outside into the light-emitting element 23. At least one of the contact plugs 21_1 to 22_4 and the metal wirings 22_1 to 22_4 constituting the moisture-resistant ring 7 may be partially replaced with a layer of the same material as the protective layer 16. Since the protective layer 16 is formed of a material that can reduce the penetration of moisture, even if such a replacement is made, the moisture resistance of the moisture-resistant ring 7 can be maintained. In this embodiment, a structure having such a replacement is also referred to as a moisture-resistant ring.

[0033] In the example shown in FIG. 6, the contact-permitted regions 10 with which the protrusions 6 of the deposition mask 4 come into contact are provided at two locations on the light-emitting device. Thus, in a plan view (plan view) as shown in FIG. 6, the moisture-resistant wall 71 constituting a part of the first moisture-resistant ring 7 has two recesses away from the first side S1, and the contact-permitted regions 10 are arranged in these recesses. Components such as pads, driving circuits, and contact regions are not present in the contact-permitted region 10. By expanding the contact-permitted region 10 as much as possible, the protective region surrounded by the first moisture-resistant ring 7 becomes narrow, reducing the possibility of defects occurring in the protective region and improving the reliability of the light-emitting device 2. Note that, as an example of a defect that may occur in the protective region, the intrusion of moisture due to damage to the protective film 16 on the protective region can be given.

[0034] The pattern portion PP of the deposition mask 4 is separated from the material substrate 1 by the protrusions 6. If the gap between the pattern portion PP and the material substrate 1 (the height of the protrusions 6) is too large, a film may be formed by deposition over a range of the material substrate 1 that is wider than the openings 5 ​​of the pattern portion PP. Therefore, the gap between the pattern portion PP and the material substrate 1 (the height of the protrusions 6) is preferably, for example, 20 μm or less, and more preferably 10 μm or less. The minimum value of the gap between the pattern portion PP and the material substrate 1 (the height of the protrusions 6) can be determined so as to ensure that the pattern portion PP and the material substrate 1 do not come into contact with each other.

[0035] The interval between adjacent protrusions 6 may also be taken into consideration. If the interval between adjacent protrusions 6 is too wide, the pattern portion PP of the deposition mask 4 and the material substrate 1 may come into contact with each other at the portions between the protrusions 6. Table 1 illustrates the results of checking whether the pattern portion PP and the material substrate 1 come into contact with each other while changing the interval between the protrusions 6 and the thickness (plate thickness) of the pattern portion PP. The height of the protrusions 6 was set to 10 μm, the magnetic force for fixing the deposition mask 4 to the material substrate 1 was set to 150 gauss, and the interval between adjacent openings 5 ​​in the Y direction was set to 250 μm. The contact between the pattern portion PP and the material substrate 1 was evaluated by measuring the particles in the area other than the contact allowable area 10 of the material substrate 1 after the protrusions 6 of the deposition mask 4 were brought into contact with the material substrate 1 with a particle counter. Here, if there were no particles, it was marked as "no contact" (○), and if there were particles, it was marked as "contact" (×).

[0036] [Table 1]

[0037] FIG. 9 shows the configuration of a light emitting device 2" of the comparative example. The light emitting device 2" of the comparative example has a rectangular moisture-resistant ring 7, and a contact-tolerant region 10 is arranged on the outside of the moisture-resistant ring 7. In such a configuration, the dimension f in the Y direction (second direction) of a unit consisting of the light emitting device 2" and the contact-tolerant region 10 is larger than the dimension e in the Y direction (second direction) of the light emitting device 2". This can reduce the number of light emitting devices 2" that can be obtained from one material substrate 1.

[0038] A manufacturing method for manufacturing the light emitting device 2 of the first embodiment may include a deposition process of depositing a material for forming a functional layer on a material substrate 1 having a plurality of rectangular substrate regions each to become a rectangular substrate RS, using a deposition mask 4. Each of the plurality of rectangular substrate regions of the material substrate 1 has a contact permissible region 10 between a portion of the moisture-resistant wall 71 that defines the shortest distance d1 and the first side S1. The deposition mask 4 may include a plurality of protrusions 6 that respectively contact the contact permissible regions 10 in the plurality of rectangular substrate regions, and a pattern portion PP having a plurality of openings 5. In the deposition process, the distance between the material substrate 1 and the pattern portion PP is defined by the plurality of protrusions 6.

[0039] Hereinafter, the light emitting device 2 of the second embodiment will be described with reference to Fig. 10. Fig. 10 shows a schematic configuration of one light emitting device 2 in the second embodiment. Note that matters not mentioned as the second embodiment may follow the first embodiment as long as no contradiction occurs.

[0040] The light emitting device 2 may include a moisture-resistant ring structure 70 arranged on the rectangular substrate RS to suppress the intrusion of moisture into the light emitting element array 3 and all the pads 8. The moisture-resistant ring structure 70 may include moisture-resistant walls 71, 72 arranged between the light emitting element array 3 and the first side S1. In FIG. 10, the moisture-resistant walls 71, 72 in the moisture-resistant ring structure 70 are indicated by thick gray lines. The shortest distance between the light emitting element array 3 and the moisture-resistant walls 71, 72 in the Y direction (second direction) is a distance d1'. The distance between the light emitting element array 3 and the moisture-resistant walls 71 on a virtual straight line VSL that is parallel to the Y direction (second direction) and passes through the light emitting element array 3 and the pads 8 is a distance d2. In the second embodiment, the distance d1' is smaller than the distance d2. This is advantageous for reducing the distance (spacing) between the light emitting devices 2 adjacent to each other in the Y direction on the material substrate 1, thereby increasing the number of light emitting devices 2 that can be formed on the material substrate 1 and reducing the manufacturing cost of the light emitting device 2.

[0041] The moisture-resistant ring structure 70 may include a first moisture-resistant ring 7 arranged to surround the light-emitting element array 3 and the pad 8, and a second moisture-resistant ring 11 arranged to not surround the light-emitting element array 3 and the pad 8 but to be surrounded by the first moisture-resistant ring 7. The first moisture-resistant ring 7 may include a portion that defines a distance d2 between the light-emitting element array 3 and the moisture-resistant walls 71, 72 on the virtual straight line VSL, and the second moisture-resistant ring 11 may include a portion that defines the shortest distance d1' between the light-emitting element array 3 and the moisture-resistant walls 71, 72. The first moisture-resistant ring 7 may be arranged to surround the light-emitting element array 3 and the pad 8 over the entire circumference. The second moisture-resistant ring 11 may be arranged to surround a structure arranged inside the second moisture-resistant ring 11 over the entire circumference.

[0042] Hereinafter, the light emitting device 2 of the third embodiment will be described with reference to Fig. 11. Fig. 11 shows a schematic configuration of one light emitting device 2 in the third embodiment. Note that matters not mentioned as the third embodiment may follow at least one of the first and second embodiments as long as no contradiction occurs.

[0043] The light emitting device 2 may include a moisture-resistant ring structure 70 disposed on the rectangular substrate RS so as to suppress the intrusion of moisture into the light emitting element array 3 and all the pads 8. The moisture-resistant ring structure 70 may include moisture-resistant walls 71, 72 disposed between the light emitting element array 3 and the first side S1. In FIG. 11, the moisture-resistant walls 71, 72 in the moisture-resistant ring structure 70 are indicated by thick gray lines. The shortest distance between the light emitting element array 3 and the moisture-resistant walls 71, 72 in the Y direction (second direction) is a distance d1'. In the example of FIG. 11, the shortest distance between the light emitting element array 3 and the moisture-resistant wall 71 in the Y direction (second direction) and the shortest distance between the light emitting element array 3 and the moisture-resistant wall 72 in the Y direction (second direction) are both distances d1'. However, at least one of the shortest distance between the light emitting element array 3 and the moisture-resistant wall 71 in the Y direction (second direction) and the shortest distance between the light emitting element array 3 and the moisture-resistant wall 72 in the Y direction (second direction) may be the distance d1'. The distance between the light-emitting element array 3 and the moisture-resistant wall 71 on the virtual straight line VSL that is parallel to the Y direction (second direction) and passes through the light-emitting element array 3 and the pads 8 is d2. In the third embodiment, the distance d1' is smaller than the distance d2. This is advantageous for reducing the distance (spacing) between adjacent light-emitting devices 2 in the Y direction on the material substrate 1, thereby increasing the number of light-emitting devices 2 that can be formed on the material substrate 1 and reducing the manufacturing cost of the light-emitting devices 2.

[0044] The moisture-resistant ring structure 70 may include a first moisture-resistant ring 7 arranged to surround the light-emitting element array 3 and the pad 8, and a second moisture-resistant ring 11 arranged to not surround the light-emitting element array 3 and the pad 8, but to be surrounded by the first moisture-resistant ring 7. The first moisture-resistant ring 7 may include a portion that defines a distance d2 between the light-emitting element array 3 and the moisture-resistant walls 71, 72 on the virtual straight line VSL. At least one of the first moisture-resistant ring 7 and the second moisture-resistant ring 11 may include a portion that defines the shortest distance d1' between the light-emitting element array 3 and the moisture-resistant walls 71, 72. The first moisture-resistant ring 7 may be arranged to surround the light-emitting element array 3 and the pad 8 over the entire circumference. The second moisture-resistant ring 11 may be arranged to surround a structure arranged inside the second moisture-resistant ring 11 over the entire circumference.

[0045] A light emitting device 402 according to the fourth embodiment will be described below with reference to Figs. 16 to 21. Any matters not mentioned as the fourth embodiment may conform to at least one of the first to third embodiments unless a contradiction arises. Numerical values, shapes, materials, components, arrangements and connection forms of the components described herein do not limit the scope of disclosure unless expressly stated to be limiting.

[0046] In the following, an OLED will be described as an example of a light-emitting element, but the present disclosure is not limited to OLEDs and can be applied to current-driven light-emitting devices in general.

[0047] FIG. 16(a) shows an example in which a light emitting device 402 according to the fourth embodiment is formed on a material substrate 401 such as a silicon wafer. The light emitting devices 402 can be formed in a matrix on the substrate 401. In the case of a rectangular light emitting device 402, the yield of one material substrate 401 varies greatly depending on the size of the short side, so it is effective in reducing costs to shorten the short side as much as possible. In addition, when a silicon wafer is used as a substrate for manufacturing the light emitting device 402, it is possible to form a driving circuit finely. As a result, it is possible to increase the density of the OLED. The increase in density allows for the formation of higher-definition images.

[0048] 16(b) shows an example of a deposition mask 403 for forming an OLED on a light-emitting device 402. A plurality of openings 404 are arranged in the deposition mask 403, and the arrangement intervals of the plurality of openings 404 and the arrangement intervals of the plurality of light-emitting devices 402 are equal to each other. After the light-emitting device 402 on the material substrate 401 and the openings 404 of the deposition mask 403 are overlapped in a plan view, the material substrate 401 and the ribs 405 of the deposition mask 403 are brought into close contact with each other, and electrodes and organic layers are deposited on the light-emitting device by a vacuum deposition method to form an OLED.

[0049] 16(c) shows an example of a cross-sectional structure when the material 401 and the rib 405 of the deposition mask 403 are in close contact with each other. The rib 405 of the deposition mask 403 makes it possible to maintain a constant distance between the material substrate 401 and the pattern portion (portion other than the rib 405) of the deposition mask 403 when the material substrate 401 and the rib 405 of the deposition mask 403 are in close contact with each other. In addition, the rib 405 minimizes the area where the deposition mask 403 comes into contact with the light-emitting device 402, thereby preventing the transfer of foreign matter and scratches on the light-emitting device 402 and preventing the occurrence of sealing defects.

[0050] Fig. 17 is a schematic cross-sectional view showing an example of an OLED 420 and a transistor 414 connected to the OLED 420. The transistor is an example of an active element. The transistor may be a thin film transistor (TFT). Fig. 17 shows the OLED 420 and the transistor 414. A drain 412 and a source 411 of the transistor 414 are disposed on a silicon substrate 410, and a gate 413 of the transistor 414 is disposed on the silicon substrate 410 via a gate insulating film (not shown).

[0051] There are a plurality of contact plugs 415_1 to 415_4 and a plurality of metal wirings 416_1 to 416_4 that electrically connect the drain 412 of the transistor 414 and the OLED 420, and an insulating layer 419 is provided between each of the wirings. In Fig. 17, the insulating layer 419 is illustrated as a single layer, but the insulating layer 419 may have a laminated structure made up of a plurality of layers.

[0052] The OLED 420 may be composed of a first electrode 416-4, an organic film 421 having a light-emitting layer, and a second electrode 422. In FIG. 17, the organic film 421 is illustrated as one layer, but the organic film 421 may be composed of multiple layers. In the OLED 420, the second electrode 422 is a transparent electrode, and light from the organic film 421 is extracted to the outside through the second electrode 422. A protective layer 425 for reducing deterioration of the OLED 420 is provided on the second electrode 422. The second electrode 422 of the OLED 420 is shared by multiple OLEDs 420 and serves as a common electrode.

[0053] In the light-emitting device 402, a structural unit formed by a combination of an OLED 420 and a transistor 414 is repeatedly arranged in the row and column directions. Between each OLED 420, a structure 427 having a large step may be formed in the layer immediately below the organic film 421. The structure 427 may be formed so as to electrically separate the organic film 421 while electrically connecting the second electrode 422. The method of electrical connection between the OLED 420 and the electrodes (source electrode, drain electrode) included in the transistor 414 is not limited to the embodiment shown in FIG. 17. Either the source electrode or the drain electrode of the transistor 414 may be electrically connected to the first electrode 416_4 of the OLED 420 depending on the polarity of the OLED 420 and the first electrode 416_4 and the polarity of the transistor 414. In FIG. 17, a transistor is used as a switching element, but other switching elements may be used instead.

[0054] The transistor is not limited to a transistor formed on a single crystal silicon wafer, but may be a thin film transistor having an active layer on an insulating surface of a substrate. Examples of the active layer include non-single crystal silicon such as single crystal silicon, amorphous silicon, and microcrystalline silicon, and non-single crystal oxide semiconductors such as indium zinc oxide and indium gallium zinc oxide.

[0055] 18 is a schematic diagram showing one form of a light emitting device 402 according to the fourth embodiment. The light emitting device 402 of the fourth embodiment has a rectangular shape having long sides parallel to a first direction and short sides parallel to a direction intersecting the first direction.

[0056] In the light-emitting device 402, when the light-emitting region 102 is formed along the long side direction, components other than the light-emitting region 102, such as a contact region, can be arranged in the peripheral region of the light-emitting region 102, adjacent to the light-emitting region 102 in the short side direction.

[0057] The substrate 101 has a rectangular shape. In this specification, the long side direction of the rectangular substrate 101 is referred to as a first direction, and the short side direction perpendicular to the long side direction is referred to as a second direction. A moisture-resistant ring 100 that serves to prevent moisture from entering the inside of the light-emitting device 402 is arranged on the rectangular substrate 101. In addition, a light-emitting region 102, a first contact region 103_1 and a second contact region 103_2, and pads 104_1 and 104_2 are arranged in an area surrounded by the moisture-resistant ring 100. A plurality of light-emitting elements are arranged in a row and column direction in the light-emitting region 102. The first contact region 103_1 and the second contact region 103_2 are regions in which wiring that is electrically connected to a common electrode of the OLED is arranged. The pads 104_1 and 104_2 are electrically connected to the contact region.

[0058] A plurality of light-emitting elements are arranged in a matrix in light-emitting region 102. As described above, each light-emitting element is composed of a light-emitting layer and a first electrode and a second electrode that sandwich the light-emitting layer, the first electrode being an independent electrode provided for each light-emitting element, and the second electrode being a common electrode provided for all light-emitting elements.

[0059] The first contact region 103_1 and the second contact region 103_2 are provided in a region adjacent to the light emitting region 102 of the substrate 101 and surrounded by the moisture-resistant ring 100. The recess 105, the first contact region 103_1 and the second contact region 103_2, and the pads 104_1 and 104_2 are disposed between the light emitting region 102 and one long side end of the substrate 101. In other words, the recess 105, the first contact region 103_1 and the second contact region 103_2, and the pads 104_1 and 104_2 may be disposed in one short side direction as viewed from the light emitting region 102. The recess 105 may be disposed between the first contact region 103_1 and the second contact region 103_2. Further, the recess 105, the first contact region 103_1 and the second contact region 103_2, and the pads 104_1 and 104_2 are arranged in series along the long side direction. In the example of Fig. 18, the pad 104_1, the first contact region 103_1, the recess 105, the second contact region 103_2, and the pad 104_2 are arranged in series along the long side direction in this order.

[0060] The moisture-resistant ring 100 is a guard ring made of a wiring layer, and is provided to surround the light-emitting region 102, the first contact region 103_1, the second contact region 103_2, and the pads 104_1 and 104_2. The moisture-resistant ring 100 may have one or more recesses 105 on one of the long sides of the substrate. The moisture-resistant ring 100 may have a narrow portion 100_2 and wide portions 100_1 and 100_3 provided on both sides of the long side direction (first direction) of the narrow portion 100_2. The width of the narrow portion 100_2 in the short side direction (second direction) may be shorter than the width of the wide portions 100_1 and 100_3 in the short side direction, and the width of the wide portions 100_1 and 100_3 in the short side direction may be longer than the width of the narrow portion 100_2 in the short side direction. The position of one of the long sides of the narrow portion 100_2 and the wide portions 100_1 and 100_3 in the short side direction may be the same, and the position of the other long side in the short side direction may be different. Due to the presence of the narrow portion 100_2, the moisture-resistant ring 100 has a concave portion on the outer periphery. This portion is referred to as a recess 105 in this embodiment. The recess 105 may be used as a contact region for contacting a rib 405, which is a part of the deposition mask 403, in the film formation process. The narrow portion 100_2 may have a shorter width in the short side direction than the wide portions 100_1 and 100_3 by the width of the recess 105 in the short side direction. The first contact region 103_1 and the second contact region 103_2 are disposed inside the wide portions 100_1 and 100_3 of the moisture-resistant ring 100, respectively.

[0061] A driving circuit for the light-emitting device 402 may be formed inside the moisture-resistant ring 100 (not shown). When forming the OLED, the rib 005 of the deposition mask 403 abuts against the recess 105 of the moisture-resistant ring 100, in other words, against the outside of the moisture-resistant ring 100 at the narrow width portion 100_2, and the distance between the substrate and the pattern portion of the mask 403 is kept constant. The rib 405 serves to minimize the contact surface between the deposition mask 403 and the light-emitting device 402, prevent foreign matter transfer and scratches on the light-emitting device 402, and prevent sealing failure. In addition, when the rib 405 abuts against the substrate, scratches may occur in the insulating film on the substrate, and the sealing performance of the light-emitting device 402 may be reduced. In this embodiment, the recess 105, which is the contact area of ​​the rib 405, is disposed outside the moisture-resistant ring to ensure the sealing performance of the light-emitting device 402.

[0062] The second electrode (upper electrode / common electrode) 422 of the OLED of this embodiment is made of a transparent electrode material, and therefore has a relatively high wiring resistance. In addition, since the second electrode 422 is also a common electrode, current flows from multiple OLEDs, and the voltage drop at the second electrode 422 becomes large. Therefore, a difference in voltage applied to each OLED may occur depending on the distance from the contact region to which the potential is supplied. As a result, the actual emission brightness may differ between OLEDs to which a voltage for emitting light with the same brightness is applied, and shading, etc. may occur.

[0063] The light emitting device 402 of this embodiment may have at least two contact regions (103_1, 103_2) between the second electrode (upper electrode / common electrode) 422 and the power supply wiring along the long side edge of the light emitting device 402. The second electrode 422 contacts the low-resistance power supply wiring at multiple positions in the long side direction, thereby reducing the voltage drop in the second electrode 422. Therefore, even if multiple OLEDs have a common second electrode 422, it is possible to suppress the voltage drop that depends on the position of the second electrode 422 and to suppress shading of light emission brightness.

[0064] It is also possible to arrange the first contact region 103_1 or the second contact region 103_2 and the abutment region of the rib 405 of the deposition mask 403 in series along the short side direction of the light emitting device 402. However, in that case, a region dedicated to the rib is provided between the light emitting devices 402 in the short side direction, and the size of the light emitting device 402 increases by the amount of the dedicated rib region. In the light emitting device 402 of this embodiment, the recess 105 of the moisture-resistant ring, which is the rib abutment region, is arranged between the first contact region 103_1 and the second contact region 103_2, thereby reducing the distance between the light emitting devices 402 in the short side direction. Therefore, the number of light emitting devices 402 that can be arranged in the short side direction on one substrate can be increased, thereby increasing the yield.

[0065] Fig. 19 is an E-E' cross-sectional view of the light emitting device 402 of Fig. 18. The moisture-resistant ring 100_2 has a laminated structure in which contact plugs 445_1-445_4 and metal wirings 446_1-446_4 are laminated, and extends from the surface of the light emitting device 402 to a depth reaching the silicon substrate 410 on which the circuit elements are formed. The contact plugs 445_1-445_4 and metal wirings 446_1-446_4 constituting the moisture-resistant ring 100_2 are formed in the same layer as the contact plugs 415_1-415_4 and metal wirings 416_1-416_4 constituting the wiring 417. In this way, the moisture-resistant ring 100_2 has the same layer structure as the multilayer wiring structure of the internal circuit, and can be formed simultaneously with the internal circuit by a common process.

[0066] The cross-sectional structure of the moisture-resistant ring 100_1 can have the same structure as that of the moisture-resistant ring 040_2 at any point in the light-emitting device 402.

[0067] Moreover, the moisture-resistant rings 100_1 and 100_2 are in physical contact with the protective layer 025 of the OLED 420, and serve to prevent moisture from penetrating into the OLED 420.

[0068] In the scribe region 441, the protective layer 425 of the OLED 420 is removed. This makes it possible to prevent the protective layer 425 from being chipped when the light emitting device 402 is cut from the silicon substrate 410.

[0069] In the contact region 103_1, the second electrode (common electrode) 422 of the OLED 420 and the metal wiring 456_4 are in physical contact with each other. The pad 104_1 is made of a metal wiring in the same layer as the metal wiring 456_3. The low-resistance metal wiring 456_3 is drawn from the pad 104_1 to just below the contact region 103_1, and the metal wiring 456_3 and the metal wiring 456_4 are electrically connected with low resistance by the contact plug 455-4. In this embodiment, the pad 104_1 is in the same layer as the metal wiring 456_3, but may be, for example, a wiring in the same layer as the metal wiring 456_4.

[0070] By adopting the configuration described in this embodiment, it is possible to obtain the effect of suppressing shading of the luminance of the light emitting device 402, improving the yield, and achieving low-cost manufacturing.

[0071] Hereinafter, a light emitting device 402 according to the fifth embodiment will be described with reference to Fig. 20. In addition, matters not mentioned in the fifth embodiment may follow the fourth embodiment unless a contradiction occurs. Fig. 20 is a schematic diagram showing the configuration of the light emitting device according to the fifth embodiment.

[0072] On a rectangular substrate 101, there are arranged a moisture-resistant ring 200, a light-emitting region 102 in which light-emitting pixels arranged in rows and columns are arranged, contact regions 203_1 to 203_5 electrically connected to a common electrode of the OLED, and pads 204_1 to 204_3 electrically connected to the contact regions.

[0073] In this embodiment, the moisture-resistant ring 200 is configured by alternately arranging five wide portions 200_1, 200_3, 200_5, 200_7, and 200_9 and four narrow portions 200_2, 200_4, 200_6, and 200_8. The narrow portions 200_2, 200_4, 200_6, and 200_8 are portions whose short-side widths are shorter than the short-side widths of the wide portions 200_1, 200_3, 200_5, 200_7, and 200_9. Here, an example in which there are four narrow portions is shown, but the number is not particularly limited.

[0074] Due to the presence of the wide portions 200_1, 200_3, 200_5, 200_7, and 200_9, the outer peripheral shape of the moisture-resistant ring 200 includes a plurality of recessed portions. These portions are referred to as recesses 205_1 to 205_4 of the moisture-resistant ring. The recesses 205_1 to 205_4 may be used as abutment regions for abutting ribs, which are part of a deposition mask, in a film formation process. In this embodiment, the recesses 205_1 to 205_4 of the moisture-resistant ring 200 are arranged along the long side of the light-emitting device. Therefore, the arrangement interval of the rib abutment regions on the substrate 101 can be narrowed, and deflection of the deposition mask can be suppressed. Furthermore, by narrowing the arrangement interval of the rib abutment regions, the length of each recess, which serves as the abutment region, in the long side direction can be shortened, and the interval between the first contact region and the second contact region can be reduced. Therefore, the resistance of the common electrode in the center of the light-emitting device can be further reduced, and the luminance shading of the light-emitting device can be further suppressed. By alternately arranging the contact regions 203_1 to 203_3 between the common electrode and the power supply wiring and the recesses 205_1 to 205_3 of the moisture-resistant ring on the light-emitting device, it is possible to reduce the resistance of the common electrode at a plurality of locations.

[0075] By arranging components other than the light-emitting region, such as the contact region of the light-emitting device, in series in the long side direction, the light-emitting device can be further miniaturized, the yield on the substrate can be increased, and costs can be reduced. In this specification, "component A and component B are arranged in series in a first direction" means that component A and component B have an overlapping portion when viewed in plan from the first direction on a surface perpendicular to the first direction.

[0076] Hereinafter, a light emitting device 402 according to the sixth embodiment will be described with reference to FIG. 21. In addition, matters not mentioned as the sixth embodiment may follow the fifth embodiment unless there is a contradiction. FIG. 21 is a schematic diagram showing a configuration of a light emitting device according to the sixth embodiment. Compared with the light emitting device of FIG. 20, circuits 206_1 and 206_2 for driving the light emitting elements are added. The circuits 206_1 to 206_2 are arranged in series in the long side direction. In other words, the circuits 206_1 to 206_3 are additionally arranged so as to overlap in a plan view with respect to a surface perpendicular to the long side direction. In addition, the circuits 206_1 to 206_2 are also arranged in series with the contact regions 203_1 to 203_3 and the pads 204_1 to 204_3 in the long side direction.

[0077] Specific examples of the circuits 206_1 to 206_2 include, but are not limited to, an input protection circuit, an input circuit to which data for each drive is input, a logic circuit for processing data, etc. Regardless of the type of circuit, the length of the light emitting device in the short side direction can be reduced by providing a circuit region in the same position as the contact region and the pad region in the short side direction and arranging the circuit in the circuit region.

[0078] Fig. 22 is a cross-sectional view taken along the line FF' of the light emitting device of Fig. 21. Compared to Fig. 19, circuits 206_1 and 206_2 are added.

[0079] By adopting the configuration described in this embodiment, shading of the luminance of the light emitting device can be effectively suppressed.

[0080] Hereinafter, an image forming apparatus 100 incorporating the light emitting device 2 representative of the first to sixth embodiments will be described with reference to FIG. 12. FIG. 12 shows a schematic configuration of the image forming apparatus 100. The image forming apparatus 100 may be configured as an electrophotographic image forming apparatus. The image forming apparatus 100 may include a photoconductor 101, a charging unit 102 for charging the photoconductor 101, an exposure unit 103 for exposing the surface of the photoconductor 101 to light so as to form an electrostatic latent image on the surface, and a development unit 104 for developing the electrostatic latent image. The exposure unit 103 may include the above-mentioned light emitting device 2 as a light source. The development unit 104 may form an image by, for example, attaching toner to the electrostatic latent image. The image forming apparatus 100 may further include a transfer unit 105 for transferring the image formed by the development unit 104 to a recording medium 107, and a fixing unit 108 for fixing the image transferred to the recording medium 107.

[0081] In the figure, the X direction is expressed as the column (the direction in which the columns are arranged), and the Y direction is expressed as the row (the direction in which the rows are arranged). Here, the X direction may be the direction along the rotation axis of the photoconductor 101 of the image forming apparatus 100. In order to configure the light source of the exposure unit 103, a plurality of light emitting devices 2 may be arranged. In one example, the plurality of light emitting devices 2 may be arranged to configure a staggered arrangement, as illustrated in FIG. 13. The light emitting devices in each light emitting device array 3 may be arranged in one row, or may be arranged to configure multiple rows. The configuration in which the light emitting devices are arranged to configure multiple rows in each light emitting device array 3 is advantageous for gradation expression, and is also advantageous for reducing the amount of light emitted by each light emitting device and extending the life of the light emitting device. When the light emitting devices are arranged to configure multiple rows in each light emitting device array 3, when there are four rows of light emitting devices, as illustrated in FIG. 14, the initial position of the light emitting device in the first row and the initial position of the light emitting device in the second row may be shifted in the X direction by 1 / 4 of the X-direction dimension of the light emitting device. In the case of n rows, the initial positions of the light emitting elements in the first row and the second row may be shifted in the X direction by 1 / n of the X-directional dimension of the light emitting elements. Such a configuration is advantageous for improving the resolution.

[0082] Hereinafter, each of the components of the light emitting device 2 will be described in detail by way of example. [Structure of organic light-emitting element] The organic light-emitting element is provided by forming an insulating layer, a first electrode, an organic film, and a second electrode on a substrate. A protective layer, a color filter, a microlens, etc. may be provided on the cathode. When a color filter is provided, a planarizing layer may be provided between the protective layer. The planarizing layer may be made of acrylic resin, etc. The same applies when a planarizing layer is provided between the color filter and the microlens. [substrate] Examples of the substrate include quartz, glass, silicon wafer, resin, and metal. In addition, a switching element such as a transistor and wiring may be provided on the substrate, and an insulating layer may be provided thereon. As the insulating layer, any material can be used as long as it can form a contact hole so that wiring can be formed between the first electrode and the insulating layer, and insulation from wiring that is not connected can be ensured. For example, resin such as polyimide, silicon oxide, silicon nitride, etc. can be used. [electrode] A pair of electrodes can be used. The pair of electrodes may be an anode and a cathode. When an electric field is applied in the direction in which the organic light-emitting element emits light, the electrode with a higher potential is the anode, and the other is the cathode. It can also be said that the electrode that supplies holes to the light-emitting layer is the anode, and the electrode that supplies electrons is the cathode.

[0083] The material constituting the anode should have as large a work function as possible. For example, metals such as gold, platinum, silver, copper, nickel, palladium, cobalt, selenium, vanadium, tungsten, etc., mixtures containing these metals, alloys combining these metals, metal oxides such as tin oxide, zinc oxide, indium oxide, indium tin oxide (ITO), and indium zinc oxide can be used. Conductive polymers such as polyaniline, polypyrrole, and polythiophene can also be used.

[0084] These electrode materials may be used alone or in combination of two or more kinds. The anode may be composed of a single layer or a plurality of layers.

[0085] When used as a reflective electrode, for example, chromium, aluminum, silver, titanium, tungsten, molybdenum, or alloys or laminates thereof can be used. The above materials can also function as a reflective film without serving as an electrode. When used as a transparent electrode, a transparent conductive layer of oxide such as indium tin oxide (ITO) or indium zinc oxide can be used, but is not limited to these. Photolithography technology can be used to form the electrode.

[0086] On the other hand, the material for the cathode should have a small work function. Examples of the material include alkali metals such as lithium, alkaline earth metals such as calcium, aluminum, titanium, manganese, silver, lead, chromium, and other metals or mixtures containing these metals. Alternatively, alloys combining these metals can be used. For example, magnesium-silver, aluminum-lithium, aluminum-magnesium, silver-copper, zinc-silver, and the like can be used. Metal oxides such as indium tin oxide (ITO) can also be used. These electrode materials may be used alone or in combination of two or more types. The cathode may have a single layer structure or a multi-layer structure. Among these, it is preferable to use silver, and it is even more preferable to use a silver alloy to reduce the aggregation of silver. As long as the aggregation of silver can be reduced, the ratio of the alloy is not important. For example, the ratio of silver to other metals may be 1:1, 3:1, and the like.

[0087] The cathode may be a top-emission element using an oxide conductive layer such as ITO, or a bottom-emission element using a reflective electrode such as aluminum (Al), and is not particularly limited. The method for forming the cathode is not particularly limited, but it is more preferable to use a direct current or alternating current sputtering method, etc., since the film coverage is good and the resistance can be easily reduced. [Pixel isolation layer] The pixel separation layer is formed of a silicon nitride (SiN) film, a silicon oxynitride (SiON) film, or a silicon oxide (SiO) film formed by chemical vapor deposition (CVD). In order to increase the in-plane resistance of the organic film, it is preferable that the thickness of the organic film, particularly the hole transport layer, is thin on the sidewall of the pixel separation layer. Specifically, the thickness of the sidewall can be thinned by increasing the taper angle of the sidewall of the pixel separation layer or the thickness of the pixel separation layer to increase vignetting during deposition.

[0088] On the other hand, it is preferable to adjust the sidewall taper angle and film thickness of the pixel separation layer to such an extent that no voids are formed in the protective layer formed thereon. Since no voids are formed in the protective layer, the occurrence of defects in the protective layer can be reduced. Since the occurrence of defects in the protective layer is reduced, deterioration in reliability such as the occurrence of dark spots and poor conduction of the second electrode can be reduced.

[0089] According to this embodiment, even if the taper angle of the sidewall of the pixel separation layer is not steep, it is possible to effectively suppress charge leakage to adjacent pixels. As a result of this study, it was found that the charge leakage can be sufficiently reduced if the taper angle is in the range of 60 degrees or more and 90 degrees or less. The thickness of the pixel separation layer is preferably 10 nm or more and 150 nm or less. The same effect can be obtained even if the pixel separation layer is composed only of a pixel electrode without a pixel separation layer. However, in this case, it is preferable that the thickness of the pixel electrode is half or less than that of the organic layer, or the edge of the pixel electrode is forward tapered by less than 60 degrees, because this reduces short circuits of the organic light-emitting element. [Organic film] The organic film may be formed as a single layer or as multiple layers. When the organic film has multiple layers, it may be called a hole injection layer, a hole transport layer, an electron blocking layer, a light emitting layer, a hole blocking layer, an electron transport layer, an electron injection layer, etc., depending on its function. The organic film is mainly composed of an organic compound, but may also contain inorganic atoms and inorganic compounds. For example, it may contain copper, lithium, magnesium, aluminum, iridium, platinum, molybdenum, zinc, etc. The organic film may be disposed between the first electrode and the second electrode, or may be disposed in contact with the first electrode and the second electrode.

[0090] In the case where the device has a plurality of light-emitting layers, the charge generating portion may be provided between the first light-emitting layer and the second light-emitting layer. The charge generating portion may have an organic compound having a lowest unoccupied molecular orbital energy (LUMO) of -5.0 eV or less. The same applies when the charge generating portion is provided between the second light-emitting layer and the third light-emitting layer. [Protective layer] A protective layer may be provided on the second electrode. For example, by bonding glass provided with a moisture absorbent on the second electrode, it is possible to reduce the intrusion of water and the like into the organic film and reduce the occurrence of display defects. In another embodiment, a passivation film such as silicon nitride may be provided on the cathode to reduce the intrusion of water and the like into the organic film. For example, after forming the cathode, the cathode may be transported to another chamber without breaking the vacuum, and a silicon nitride film having a thickness of 2 μm may be formed by the CVD method to form a protective layer. A protective layer may be provided using the atomic deposition method (ALD method) after the film formation by the CVD method. The material of the film by the ALD method is not limited, and may be silicon nitride, silicon oxide, aluminum oxide, etc. Silicon nitride may be further formed by the CVD method on the film formed by the ALD method. The film by the ALD method may have a smaller thickness than the film formed by the CVD method. Specifically, it may be 50% or less, or even 10% or less. [Color Filter] A color filter may be provided on the protective layer. For example, a color filter taking into consideration the size of the organic light-emitting element may be provided on another substrate and then bonded to the substrate on which the organic light-emitting element is provided, or a color filter may be patterned on the protective layer described above using a photolithography technique. The color filter may be made of a polymer. [Planarization layer] A planarization layer may be provided between the color filter and the protective layer. The planarization layer is provided for the purpose of reducing unevenness of the layer below. It may also be called a material resin layer without limiting the purpose. The planarization layer may be composed of an organic compound, and may be either a low molecular weight or a high molecular weight, but is preferably a high molecular weight.

[0091] The planarization layer may be provided above and below the color filter, and may be made of the same or different materials.Specific examples of the materials include polyvinylcarbazole resin, polycarbonate resin, polyester resin, ABS resin, acrylic resin, polyimide resin, phenol resin, epoxy resin, silicone resin, and urea resin. [Microlens] The organic light-emitting device may have an optical member such as a microlens on its light-emitting side. The microlens may be made of acrylic resin, epoxy resin, or the like. The microlens may be intended to increase the amount of light extracted from the organic light-emitting device and control the direction of the extracted light. The microlens may have a hemispherical shape. When the microlens has a hemispherical shape, among the tangents to the hemisphere, there is a tangent that is parallel to the insulating layer, and the tangent and the hemisphere are the vertices of the microlens. The vertex of the microlens can be determined in the same manner in any cross-sectional view. In other words, among the tangents to the semicircle of the microlens in the cross-sectional view, there is a tangent that is parallel to the insulating layer, and the tangent and the semicircle are the vertices of the microlens.

[0092] It is also possible to define the midpoint of the microlens. In the cross section of the microlens, a line segment is imaginary from a point where an arc shape ends to a point where another arc shape ends, and the midpoint of the line segment can be called the midpoint of the microlens. The cross section for determining the vertex and midpoint may be a cross section perpendicular to the insulating layer.

[0093] The microlens has a first surface having a convex portion and a second surface opposite to the first surface. It is preferable that the second surface is disposed closer to the functional layer than the first surface. In order to adopt such a configuration, it is necessary to form a microlens on the light-emitting device. When the functional layer is an organic layer, it is preferable to avoid a process in which the manufacturing process becomes high temperature. In addition, when adopting a configuration in which the second surface is disposed closer to the functional layer than the first surface, it is preferable that the glass transition temperature of all the organic compounds constituting the organic layer is 100°C or higher, and more preferably 130°C or higher. [Opposite substrate] A counter substrate may be provided on the planarization layer. The counter substrate is called a counter substrate because it is provided at a position corresponding to the aforementioned substrate. The constituent material of the counter substrate may be the same as that of the aforementioned substrate. When the aforementioned substrate is a first substrate, the counter substrate may be a second substrate. [Organic layer] The organic films (hole injection layer, hole transport layer, electron blocking layer, light emitting layer, hole blocking layer, electron transport layer, electron injection layer, etc.) constituting the organic light emitting device according to one embodiment of the present invention are formed by the method shown below.

[0094] The organic film constituting the organic light-emitting device according to one embodiment of the present invention can be formed by dry processes such as vacuum deposition, ionization deposition, sputtering, plasma, etc. Alternatively to the dry process, a wet process can be used in which a layer is formed by dissolving the material in an appropriate solvent and applying a known coating method (e.g., spin coating, dipping, casting, LB method, inkjet method, etc.).

[0095] Here, when the layer is formed by a vacuum deposition method or a solution coating method, crystallization is unlikely to occur and the layer has excellent stability over time. When the layer is formed by a coating method, the layer can be formed by combining with a suitable binder resin.

[0096] Examples of the binder resin include, but are not limited to, polyvinylcarbazole resin, polycarbonate resin, polyester resin, ABS resin, acrylic resin, polyimide resin, phenol resin, epoxy resin, silicone resin, and urea resin.

[0097] These binder resins may be used alone or in combination as homopolymers or copolymers, and may further include known additives such as plasticizers, antioxidants, and ultraviolet absorbers, if necessary.

[0098] The disclosure of the present specification and drawings will be described below by way of example. The present specification and drawings disclose at least the following items. (Item 1) A light emitting device having a rectangular substrate having a first side and a second side parallel to a first direction and a third side and a fourth side parallel to a second direction perpendicular to the first direction, a light-emitting element array including a plurality of light-emitting elements arranged on the rectangular substrate; a pad disposed on the rectangular substrate so as to be located between the first side and the light emitting element array; a moisture-resistant ring structure disposed on the rectangular substrate so as to prevent moisture from entering the light-emitting element array and the pads; the moisture-resistant ring structure includes a moisture-resistant wall disposed between the light-emitting element array and the first side, a shortest distance between the light-emitting element array and the moisture-resistant wall in the second direction is smaller than a distance between the light-emitting element array and the moisture-resistant wall on a virtual line that is parallel to the second direction and passes through the light-emitting element array and the pad; A light emitting device characterized by: (Item 2) the moisture-resistant ring structure includes a first moisture-resistant ring arranged to surround the light-emitting element array and the pad; The moisture-resistant wall is a part of the first moisture-resistant ring. 2. The light emitting device according to item 1, (Item 3) the moisture-resistant ring structure includes a first moisture-resistant ring arranged to surround the light-emitting element array and the pad, and a second moisture-resistant ring arranged not to surround the light-emitting element array and the pad but to be surrounded by the first moisture-resistant ring; the first moisture-resistant ring includes a portion that defines the distance between the light-emitting element array and the moisture-resistant wall on the virtual straight line, the second moisture-resistant ring includes a portion that defines the shortest distance between the light-emitting element array and the moisture-resistant wall; 2. The light emitting device according to item 1, (Item 4) the moisture-resistant ring structure includes a first moisture-resistant ring arranged to surround the light-emitting element array and the pad, and a second moisture-resistant ring arranged not to surround the light-emitting element array and the pad but to be surrounded by the first moisture-resistant ring; the first moisture-resistant ring includes a portion that defines the distance between the light-emitting element array and the moisture-resistant wall on the virtual straight line, At least one of the first moisture-resistant ring and the second moisture-resistant ring includes a portion that defines the shortest distance between the light-emitting element array and the moisture-resistant wall. 2. The light emitting device according to item 1, (Item 5) The first moisture-resistant ring is disposed so as to surround the entire periphery of the light-emitting element array. 5. The light emitting device according to any one of items 2 to 4, (Item 6) the first moisture-resistant ring is disposed so as to completely surround the light-emitting element array and the pads; the second moisture-resistant ring is disposed so as to completely surround the structure disposed inside the second moisture-resistant ring; 5. The light-emitting device according to item 3 or 4, (Item 7) The smallest rectangle circumscribing the light-emitting element array has a dimension in the first direction that is greater than a dimension in the second direction. 5. The light emitting device according to any one of items 2 to 4, (Item 8) Each of the plurality of light-emitting elements includes a plurality of functional layers made of an organic material. 8. The light emitting device according to any one of items 1 to 7, (Item 9) a plurality of contact regions disposed on the rectangular substrate to receive signals or potentials for driving the plurality of light emitting elements; the moisture-resistant ring structure is disposed on the rectangular substrate so as to prevent moisture from entering the light-emitting element array, the pads, and the plurality of contact regions; 9. The light emitting device according to any one of items 1 to 8, (Item 10) the plurality of contact regions include a first contact region disposed between the light-emitting element array and the first side, a second contact region disposed between the light-emitting element array and the third side, and a third contact region disposed between the light-emitting element array and the fourth side. 10. The light emitting device according to item 9, (Item 11) a portion of the moisture resistant wall that defines the shortest distance is disposed between the pad and the first contact region; 11. The light emitting device according to item 10, (Item 12) a second pad disposed on the rectangular substrate so as to be located between the first side and the light emitting element array; The portion of the moisture resistant wall that defines the shortest distance is disposed between the pad and the second pad. 12. The light emitting device according to any one of items 1 to 11, (Item 13) a trace of contact of a part of a deposition mask for forming the plurality of light-emitting elements is present between the moisture-resistant wall and the first side; 13. The light emitting device according to any one of items 1 to 12, (Item 14) A photoconductor; A charging unit that charges the photoconductor; an exposure unit that exposes the surface of the photoreceptor to light so as to form an electrostatic latent image on the surface of the photoreceptor; a developing unit that develops the electrostatic latent image, The exposure unit includes the light-emitting device according to any one of items 1 to 13. 1. An image forming apparatus comprising: (Item 15) A method for manufacturing a light emitting device, comprising the steps of: the light emitting device comprises a rectangular substrate having a first side and a second side parallel to a first direction and a third side and a fourth side parallel to a second direction perpendicular to the first direction, a light emitting element array composed of a plurality of light emitting elements arranged on the rectangular substrate, a pad arranged on the rectangular substrate so as to be located between the first side and the light emitting element array, and a moisture-resistant ring structure arranged on the rectangular substrate so as to surround the light emitting element array and the pad, the moisture-resistant ring structure including a moisture-resistant wall arranged between the light emitting element array and the first side, the shortest distance between the light emitting element array and the moisture-resistant wall in the second direction being smaller than the distance between the light emitting element array and the moisture-resistant wall on a virtual straight line parallel to the second direction and passing through the light emitting element array and the pad, The manufacturing method includes a vapor deposition step of depositing a material for forming a functional layer on a material substrate having a plurality of rectangular substrate regions each of which is to become the rectangular substrate, using a vapor deposition mask; Each of the rectangular substrate regions of the material substrate has a contact allowance region between a portion of the moisture resistant wall that defines the shortest distance and the first side, the deposition mask includes a pattern portion having a plurality of protrusions each in contact with the contact allowing regions in the plurality of rectangular substrate regions, and a plurality of openings; In the deposition step, the distance between the material substrate and the pattern portion is defined by the plurality of protrusions. A method for manufacturing a light emitting device comprising the steps of: (Item 16) the moisture-resistant ring structure includes a first moisture-resistant ring arranged to surround the light-emitting element array and the pad; The moisture-resistant wall is a part of the first moisture-resistant ring. Item 16. A method for producing a light emitting device according to item 15. (Item 17) the moisture-resistant ring structure includes a first moisture-resistant ring arranged to surround the light-emitting element array and the pad, and a second moisture-resistant ring arranged not to surround the light-emitting element array and the pad but to be surrounded by the first moisture-resistant ring; the first moisture-resistant ring includes a portion that defines the distance between the light-emitting element array and the moisture-resistant wall on the virtual straight line, the second moisture-resistant ring includes a portion that defines the shortest distance between the light-emitting element array and the moisture-resistant wall; Item 16. A method for producing a light emitting device according to item 15. (Item 18) the moisture-resistant ring structure includes a first moisture-resistant ring arranged to surround the light-emitting element array and the pad, and a second moisture-resistant ring arranged not to surround the light-emitting element array and the pad but to be surrounded by the first moisture-resistant ring; the first moisture-resistant ring includes a portion that defines the distance between the light-emitting element array and the moisture-resistant wall on the virtual straight line, At least one of the first moisture-resistant ring and the second moisture-resistant ring includes a portion that defines the shortest distance between the light-emitting element array and the moisture-resistant wall. Item 16. A method for producing a light emitting device according to item 15. (Item 19) The first moisture-resistant ring is disposed so as to surround the entire periphery of the light-emitting element array. 19. A method for producing a light emitting device according to any one of items 16 to 18,

[0099] The invention is not limited to the above-described embodiments, and various modifications and variations are possible without departing from the spirit and scope of the invention. Accordingly, the following claims are appended to apprise the public of the scope of the invention. [Explanation of symbols]

[0100] 1: material substrate, 2: light emitting device, 3: light emitting element array, 4: deposition mask, 5: opening, 6: protrusion, 7: first moisture resistant ring, 8: pad, 9: contact area, 10: contact allowable area, 11: second moisture resistant ring, 12: insulating layer, 13: first electrode, 14: organic film, 15: second electrode, 16: protective film, RS: rectangular substrate, 70: moisture resistant ring structure, 71: moisture resistant wall, 72: moisture resistant wall, VSL: virtual straight line, S1: first side, S2: second side, S3: third side, S4: fourth side

Claims

1. A light emitting device having a rectangular substrate having a first side and a second side parallel to a first direction and a third side and a fourth side parallel to a second direction perpendicular to the first direction, a light-emitting element array including a plurality of light-emitting elements arranged on the rectangular substrate; a pad disposed on the rectangular substrate so as to be located between the first side and the light emitting element array; a moisture-resistant ring structure disposed on the rectangular substrate so as to prevent moisture from entering the light-emitting element array and the pads; the moisture-resistant ring structure includes a moisture-resistant wall disposed between the light-emitting element array and the first side, a shortest distance between the light-emitting element array and the moisture-resistant wall in the second direction is smaller than a distance between the light-emitting element array and the moisture-resistant wall on a virtual line that is parallel to the second direction and passes through the light-emitting element array and the pad; A light emitting device characterized by:

2. the moisture-resistant ring structure includes a first moisture-resistant ring arranged to surround the light-emitting element array and the pad; The moisture-resistant wall is a part of the first moisture-resistant ring.

2. The light emitting device according to claim 1 .

3. the moisture-resistant ring structure includes a first moisture-resistant ring arranged to surround the light-emitting element array and the pad, and a second moisture-resistant ring arranged not to surround the light-emitting element array and the pad but to be surrounded by the first moisture-resistant ring; the first moisture-resistant ring includes a portion that defines the distance between the light-emitting element array and the moisture-resistant wall on the virtual straight line, the second moisture-resistant ring includes a portion that defines the shortest distance between the light-emitting element array and the moisture-resistant wall; 2. The light emitting device according to claim 1 .

4. the moisture-resistant ring structure includes a first moisture-resistant ring arranged to surround the light-emitting element array and the pad, and a second moisture-resistant ring arranged not to surround the light-emitting element array and the pad but to be surrounded by the first moisture-resistant ring; the first moisture-resistant ring includes a portion that defines the distance between the light-emitting element array and the moisture-resistant wall on the virtual straight line, At least one of the first moisture-resistant ring and the second moisture-resistant ring includes a portion that defines the shortest distance between the light-emitting element array and the moisture-resistant wall.

2. The light emitting device according to claim 1 .

5. the first moisture-resistant ring is disposed so as to surround the entire periphery of the light-emitting element array; 5. The light emitting device according to claim 2, wherein the light emitting device is a light emitting device.

6. the first moisture-resistant ring is disposed so as to completely surround the light-emitting element array and the pads; the second moisture-proof ring is disposed so as to surround the entire periphery of the structure disposed inside the second moisture-proof ring; 5. The light emitting device according to claim 3 or 4.

7. The minimum rectangle circumscribing the light-emitting element array has a dimension in the first direction that is greater than a dimension in the second direction.

5. The light emitting device according to claim 2, wherein the light emitting device is a light emitting device.

8. Each of the plurality of light-emitting elements includes a plurality of functional layers made of an organic material.

5. The light emitting device according to claim 2, wherein the light emitting device is a light emitting device.

9. a plurality of contact regions disposed on the rectangular substrate to receive signals or potentials for driving the plurality of light emitting elements; the moisture-resistant ring structure is disposed on the rectangular substrate so as to prevent moisture from entering the light-emitting element array, the pads, and the plurality of contact regions; 5. The light emitting device according to claim 2, wherein the light emitting device is a light emitting device.

10. the plurality of contact regions include a first contact region disposed between the light-emitting element array and the first side, a second contact region disposed between the light-emitting element array and the third side, and a third contact region disposed between the light-emitting element array and the fourth side.

10. The light emitting device according to claim 9.

11. a portion of the moisture resistant wall that defines the shortest distance is disposed between the pad and the first contact region; The light emitting device according to claim 10 .

12. a second pad disposed on the rectangular substrate so as to be located between the first side and the light emitting element array; The portion of the moisture resistant wall that defines the shortest distance is disposed between the pad and the second pad.

5. The light emitting device according to claim 2, wherein the light emitting device is a light emitting device.

13. a trace of contact of a part of a deposition mask for forming the plurality of light-emitting elements is present between the moisture-resistant wall and the first side; 5. The light emitting device according to claim 2, wherein the light emitting device is a light emitting device.

14. A photoconductor; A charging unit that charges the photoconductor; an exposure unit that exposes the surface of the photoreceptor to light so as to form an electrostatic latent image on the surface of the photoreceptor; a developing unit that develops the electrostatic latent image, The exposure unit includes the light emitting device according to claim 1.

1. An image forming apparatus comprising:

15. A method for manufacturing a light emitting device, comprising the steps of: the light emitting device comprises a rectangular substrate having a first side and a second side parallel to a first direction and a third side and a fourth side parallel to a second direction perpendicular to the first direction, a light emitting element array composed of a plurality of light emitting elements arranged on the rectangular substrate, a pad arranged on the rectangular substrate so as to be located between the first side and the light emitting element array, and a moisture-resistant ring structure arranged on the rectangular substrate so as to surround the light emitting element array and the pad, the moisture-resistant ring structure including a moisture-resistant wall arranged between the light emitting element array and the first side, the shortest distance between the light emitting element array and the moisture-resistant wall in the second direction being smaller than the distance between the light emitting element array and the moisture-resistant wall on a virtual straight line parallel to the second direction and passing through the light emitting element array and the pad, The manufacturing method includes a deposition step of depositing a material for forming a functional layer on a material substrate having a plurality of rectangular substrate regions each of which is to become the rectangular substrate, using a deposition mask; Each of the rectangular substrate regions of the material substrate has a contact allowance region between a portion of the moisture resistant wall that defines the shortest distance and the first side, the deposition mask includes a pattern portion having a plurality of protrusions each in contact with the contact allowing regions in the plurality of rectangular substrate regions, and a plurality of openings; In the deposition step, the distance between the material substrate and the pattern portion is defined by the plurality of protrusions. A method for manufacturing a light emitting device comprising the steps of:

16. the moisture-resistant ring structure includes a first moisture-resistant ring arranged to surround the light-emitting element array and the pad; The moisture-resistant wall is a part of the first moisture-resistant ring. The method for manufacturing a light emitting device according to claim 15 .

17. the moisture-resistant ring structure includes a first moisture-resistant ring arranged to surround the light-emitting element array and the pad, and a second moisture-resistant ring arranged not to surround the light-emitting element array and the pad but to be surrounded by the first moisture-resistant ring; the first moisture-resistant ring includes a portion that defines the distance between the light-emitting element array and the moisture-resistant wall on the virtual straight line, the second moisture-resistant ring includes a portion that defines the shortest distance between the light-emitting element array and the moisture-resistant wall; The method for manufacturing a light emitting device according to claim 15 .

18. the moisture-resistant ring structure includes a first moisture-resistant ring arranged to surround the light-emitting element array and the pad, and a second moisture-resistant ring arranged not to surround the light-emitting element array and the pad but to be surrounded by the first moisture-resistant ring; the first moisture-resistant ring includes a portion that defines the distance between the light-emitting element array and the moisture-resistant wall on the virtual straight line, At least one of the first moisture-resistant ring and the second moisture-resistant ring includes a portion that defines the shortest distance between the light-emitting element array and the moisture-resistant wall. The method for manufacturing a light emitting device according to claim 15 .

19. the first moisture-resistant ring is disposed so as to surround the entire periphery of the light-emitting element array; 19. The method for manufacturing a light emitting device according to claim 16,

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