Light emitting apparatus, method of manufacturing light emitting apparatus, and image forming apparatus

Abstract

A light emitting apparatus, a method of manufacturing the light emitting apparatus, and an image forming apparatus are provided. The light emitting device includes: a polygonal substrate having first and second sides parallel to a first direction and third and fourth sides parallel to a second direction; a light emitting element array; a pad disposed on the substrate so as to be located between the first side and the light-emitting element array; and a moisture-proof ring structure disposed on the substrate. The moisture-proof ring structure includes a moisture-proof wall disposed between the light-emitting element array and the first edge. A shortest distance in the second direction between the light emitting element array and the moisture-proof wall is smaller than a distance in a virtual straight line parallel to the second direction and passing through the light emitting element array and the pad between the light emitting element array and the moisture-proof wall.

Description

Technical Field

[0001] The present disclosure relates to a light emitting device, a method for manufacturing a light emitting device, and an imaging device. Background Art

[0002] A light-emitting device can be obtained, which has a plurality of 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 formed in a deposition process using a deposition mask. The deposition mask has a plurality of openings. In the deposition process, the functional layer material can be deposited on the substrate through the plurality of openings. On the other hand, in order to prevent moisture from intruding into the light-emitting element having a plurality of functional layers, the light-emitting device can be provided with a moisture-proof ring. Japanese Patent Publication No. 2018-29070 discloses a light-emitting device having a rectangular protective ring.

[0003] 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 configured in such a way that the protrusions contact the contact-allowed area (area where the protrusions are allowed to contact) of the material substrate. When the contact-allowed area is configured outside the moisture-proof ring, adjacent light-emitting devices on the material substrate are separated from each other via the contact-allowed area. Therefore, this limits the number of light-emitting devices that can be obtained from one substrate. As a result, this increases the manufacturing cost of the light-emitting device. Summary of the invention

[0004] One aspect of the present disclosure provides a technique that facilitates reducing the manufacturing cost of a light emitting device having a moisture-proof ring structure.

[0005] A first aspect of the present invention provides a light-emitting device, comprising: a polygonal 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 orthogonal to the first direction; a light-emitting element array having a plurality of light-emitting elements arranged on the substrate; a solder pad arranged on the substrate in a manner of being located between the first side and the light-emitting element array; and a moisture-proof ring structure arranged on the substrate, wherein the moisture-proof ring structure includes a moisture-proof wall arranged between the light-emitting element array and the first side, and the shortest distance between the light-emitting element array and the moisture-proof wall in the second direction is smaller than the distance between the light-emitting element array and the moisture-proof wall on a virtual straight line parallel to the second direction and passing through the light-emitting element array and the solder pad.

[0006] The second aspect of the present invention provides an imaging device, comprising: a photosensitive body; a charging unit configured to charge the photosensitive body; an exposure unit configured to expose the surface of the photosensitive body to form an electrostatic latent image on the surface; and a developing unit configured to develop the electrostatic latent image, wherein the exposure unit includes a light-emitting device as defined in the first aspect.

[0007] A third aspect of the present invention provides a method for manufacturing a light-emitting device, the method comprising: preparing a polygonal substrate, on which a light-emitting element array including a plurality of light-emitting elements, a solder pad and a moisture-proof ring structure are arranged, the polygonal 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 orthogonal to the first direction, and the moisture-proof ring structure is arranged on the polygonal substrate in a manner of surrounding the light-emitting element array and the solder pad; and depositing a material for forming a functional layer on the polygonal substrate by using the deposition mask when a protrusion of a deposition mask contacts a contact allowing area located between the first side and a portion of the moisture-proof ring, wherein the solder pad and the protrusion are located on a line along the first direction.

[0008] Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 is a plan view schematically showing a plurality of light emitting devices in the process of being manufactured and arranged on a material substrate;

[0010] Figure 2 is a plan view illustrating a deposition mask;

[0011] Figure 3 yes Figure 2 an enlarged plan view of a portion of a deposition mask in;

[0012] Figure 4 is a cross-sectional view schematically showing a material substrate and a deposition mask stacked on each other;

[0013] Figure 5 is a plan view illustrating another deposition mask;

[0014] Figure 6 is a plan view schematically showing a configuration of a light emitting device according to a first embodiment;

[0015] Figure 7 is schematically shown along Figure 6 A cross-sectional view of a section taken along line BB' in FIG.

[0016] Figure 8 is schematically shown along Figure 6 A cross-sectional view of a section taken along line CC' in FIG.

[0017] Fig. 9 is a plan view schematically showing a configuration of a light emitting device according to a comparative example;

[0018] Fig.10 is a plan view schematically showing a configuration of a light emitting device according to a second embodiment;

[0019] Fig.11 is a plan view schematically showing a configuration of a light emitting device according to a third embodiment;

[0020] Fig.12 is a diagram schematically showing a configuration of an imaging device according to an embodiment;

[0021] Fig.13 is a diagram illustrating an array of a plurality of light emitting devices;

[0022] Fig.14 is a diagram for explaining a modification of the light emitting device according to the first to third embodiments;

[0023] Fig.15 is schematically shown along Figure 6 A cross-sectional view of a section taken along the line D-D' in FIG.

[0024] FIG. 16A to FIG. 16C is a diagram showing placement of a substrate for a light emitting device and placement of a deposition mask according to a fourth embodiment;

[0025] Fig.17 is a sectional view showing an example of a light emitting device according to a fourth embodiment;

[0026] Fig.18 is a plan view showing an example of a light emitting device according to a fourth embodiment;

[0027] Fig.19 is Fig.18 An example of a cross-sectional view at the E-E' plane in FIG.

[0028] Fig. 20 is a plan view showing an example of a light emitting device according to a fifth embodiment;

[0029] Fig.21 is a plan view showing an example of a light emitting device according to a sixth embodiment; and

[0030] Fig. 22 is Fig.21 Example of a cross-sectional view at the F-F' plane in FIG. DETAILED DESCRIPTION

[0031] Hereinafter, the embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments are not intended to limit the scope of the claimed invention. A plurality of features are described in the embodiments, but the invention is not limited to requiring all of these features, and a plurality of such features may be combined as appropriate. In addition, in the accompanying drawings, the same reference numerals are given to the same or similar configurations, and repeated descriptions thereof are omitted.

[0032] The structure of the light emitting device 2 according to the first embodiment and its manufacturing method will be exemplarily described below. Unless otherwise explicitly stated, the numerical value, shape, material, constituent element, placement and connection form of the constituent element, etc. are not intended to limit the scope of disclosure. 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 complicated descriptions, a light emitting device in the manufacturing process will sometimes be described as a light emitting device. In addition, in the specification and the drawings, the direction will be described according to the XYZ coordinate system. In this case, 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. For convenience of explanation, in the following description, the X direction is defined as a first direction, and the Y direction is defined as a second direction orthogonal to the first direction. For example, the Y direction and the X direction can be defined as a first direction and a second direction, respectively. In the following description, a plan view is synonymous with a plan view or is an orthogonal projection to the XY plane.

[0033] Figure 1 A plurality of light emitting devices 2 in the manufacturing process arranged on a material substrate 1 such as a silicon wafer are schematically shown. Each light emitting device 2 is provided with a light emitting element array 3 or defines a light emitting element array 3. Defining the light emitting element array 3 means that although the area where the light emitting element array 3 is planned to be formed is defined, the light emitting element array 3 is not yet 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 controlled individually, an organic film arranged on the plurality of first electrodes, and a second electrode arranged on the organic film. For example, the organic film and the second electrode may be shared by a 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.

[0034] Figure 2 A deposition mask 4 for manufacturing a plurality of light emitting devices 2 is schematically shown. Figure 2 The geometric figure or circle represented by the dotted line in the figure represents the area where the material substrate 1 is configured. Figure 3 yes Figure 2 In this case, it can be deposited by vapor deposition using Figure 2 and Figure 3 The deposition mask 4 shown forms a plurality of organic films on the light emitting element array 3 of each light emitting device 2 . Figure 4 A material substrate 1 and a deposition mask 4 stacked on each other are schematically shown. Figure 4 Corresponding to along Figure 2 The deposition mask 4 has a pattern portion PP and a plurality of protrusions 6, the pattern portion PP having a plurality of rectangular substrate regions RR, and the plurality of rectangular substrate regions RR respectively correspond to a plurality of light-emitting devices 2. Each rectangular substrate region RR may have an opening 5 for forming an organic film. Note that each rectangular substrate region RR may have a plurality of openings 5. In the deposition process, a material gas emitted from a material gas supply source may be supplied to the material substrate 1 via each opening 5.

[0035] The material substrate 1 or the plurality of light emitting devices 2 in the manufacturing process has a contact allowing area 10 as an area allowing the protrusions 6 of the deposition mask 4 to contact. The contact allowing area 10 is generally a part of the area of ​​the upper surface of the layer stacked on the material substrate 1. In this case, for simplicity, such an area is also represented as the contact allowing area 10 of the material substrate 1. Each light emitting device 2 in the manufacturing process may have at least one contact allowing area 10, preferably at least two contact allowing areas 10.

[0036] The deposition mask 4 is not in contact with the material substrate 1 (and the layers stacked on the material substrate 1) except for the contact allowing area 10 corresponding to the protrusion 6. Bringing the protrusion 6 of the deposition mask 4 into contact with the contact allowing area 10 of the material substrate 1 will define a gap between the material substrate 1 and the pattern portion PP of the deposition mask 4. This scheme is conducive to configuring the material substrate 1 and the pattern portion PP to be close to each other while maintaining a precise gap between the material substrate 1 and the pattern portion PP of the deposition mask 4. This is conducive to suppressing deposition on unnecessary areas and is also conducive to miniaturizing each light-emitting device 2. During the manufacturing process of the light-emitting device 2, contact traces of the pattern portion PP as part of the deposition mask 4 may be formed on the contact allowing area 10. Such traces may be, for example, defects.

[0037] The deposition mask 4 may be fixed to the material substrate 1 using a magnet. In this case, the deposition mask 4 may be formed of a magnetic material such as invar, etc. Alternatively, in order to fix the deposition mask 4 to the material substrate 1, a pressurizing mechanism that presses the deposition mask 4 against the material substrate 1 may be used.

[0038] By using Figure 2 and Figure 3 After forming an organic film (multiple functional layers) on the light emitting element array 3 using the deposition mask 4 shown, the organic film (multiple functional layers) can be formed by using Figure 5 The deposition mask 4 schematically shown in FIG. 4 forms the second electrode. Figure 5 The geometric figure or circle represented by the dotted line in the figure represents the area where the material substrate 1 is configured. The deposition mask 4 has a pattern portion PP and a plurality of protrusions 6, and the pattern portion PP has a plurality of rectangular substrate regions RR corresponding to the plurality of light-emitting devices 2, respectively. Each rectangular substrate region RR may have an opening 5 for forming a second electrode. After forming the plurality of second electrodes, a protective film may be formed on the entire area of ​​the material substrate 1 in such a manner as to cover the plurality of second electrodes of the material substrate 1. This makes it possible to suppress the intrusion of moisture into the organic film (multiple functional layers).

[0039] Figure 6 The configuration of a light-emitting device 2 is schematically shown. The light-emitting device 2 has a rectangular substrate RS, and the rectangular substrate RS has 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) orthogonal to the X direction (first direction). The rectangular substrate RS is a part of the material substrate 1, more specifically, a part cut from the material substrate 1 by cutting. 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 in a manner located between the first side S1 and the light-emitting element array 3. The light-emitting device 2 may also include a moisture-proof ring structure 70, which is arranged on the rectangular substrate RS in a manner to inhibit moisture from intruding into the light-emitting element array 3 and all the pads 8. The pad can be connected to an external loop. Although a rectangular substrate is illustrated below as a substrate, the shape of the substrate is not limited thereto, as long as the substrate is polygonal in a plan view. In this case, the polygonal substrate may include a substantially polygonal substrate, and may be a polygonal substrate or a rectangular substrate having rounded corners having a curved line. In addition, the light emitting area and the moisture-proof ring may have a polygonal shape other than a rectangular shape.

[0040] The moisture-proof ring structure 70 may include a moisture-proof wall 71 disposed between the light emitting element array 3 and the first side S1. Figure 6, the moisture-proof wall 71 of the moisture-proof ring structure 70 is represented by a thick gray line. The shortest distance between the light-emitting element array 3 and the moisture-proof wall 71 in the Y direction (the second direction) is the distance d1. The distance between the light-emitting element array 3 and the moisture-proof wall 71 on the virtual straight line VSL parallel to the Y direction (the second direction) and passing through the light-emitting element array 3 and the pad 8 is the distance d2. In the first embodiment, the distance d1 is smaller than the distance d2. This reduces the distance (interval) between adjacent light-emitting devices 2 on the material substrate 1 in the Y direction, and increases the number of light-emitting devices 2 that can be formed on the material substrate 1, thereby helping to reduce the manufacturing cost of the light-emitting device 2. The distance d1 can be the distance between the moisture-proof wall 71 and the first electrode 13 ( Figure 7 The distance d2 may be the shortest distance between the moisture-proof wall 71 and the first electrode 13 of the light-emitting element in the light-emitting element array 3 that is closest to the moisture-proof wall 71 on the virtual straight line VSL.

[0041] The moisture-proof ring structure 70 may include a first moisture-proof ring 7, which is configured to surround the light emitting element array 3 and the pad 8. The moisture-proof wall 71 may be a part of the first moisture-proof ring 7. The first moisture-proof ring 7 may be configured to surround the light emitting element array 3 all around.

[0042] The light-emitting device 2 may further include a plurality of contact regions 9, which are arranged on the rectangular substrate RS to receive signals or potentials for driving the plurality of light-emitting elements of the light-emitting element array 3. The plurality of contact regions 9 may be electrically connected to the second electrodes of the plurality of light-emitting elements. The moisture-proof ring structure 70 may be arranged on the rectangular substrate RS in a manner that inhibits moisture from intruding 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-proof ring 7 of the moisture-proof ring structure 70 may be arranged on the rectangular substrate RS in a manner that surrounds the light-emitting element array 3, the plurality of pads 8, and the plurality of contact regions 9. The first moisture-proof ring 7 is preferably arranged on the rectangular substrate RS in a manner that fully surrounds the light-emitting element array 3, the plurality of pads 8, and the plurality of contact regions 9.

[0043] The size of the minimum rectangle (virtual minimum rectangle) circumscribed to the light emitting element array 3 is preferably larger in the X direction (first direction) than in the Y direction (second direction). For example, the size of the minimum rectangle (virtual minimum rectangle) circumscribed to the light emitting element array 3 in the X direction (first direction) may be two or more times, three or more times, or five or more times larger than in the Y direction (second direction).

[0044] The plurality of 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 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. Figure 6 In order to distinguish the plurality of contact areas 9 from each other, the respective areas are assigned reference numerals 9a, 9b and 9c, and are collectively referred to as reference numeral 9. Figure 6 In order to distinguish the plurality of pads 8 from each other, the respective pads are assigned reference numerals 8a, 8b, 8c and 8d, and are referred to together as reference numeral 8. For example, the portion of the moisture-proof wall 71 defining the shortest distance d1 may be arranged between the first pad 8b and the first contact area 9a on the virtual straight line VSL. In addition to the first pad 8b on the virtual straight line VSL, the plurality of pads 8 may further include a second pad 8c arranged on the rectangular substrate RS in a manner of being located between the first side S1 and the light-emitting element array 3. The portion of the moisture-proof wall 71 defining the shortest distance d1 may be arranged between the first pad 8b and the second pad 8c.

[0045] Figure 7 Schematically shows the Figure 6 However, referring to Figure 7 , the illustration of the constituent elements arranged under the first electrode 13 of the light-emitting element 19 forming the light-emitting element array 3 is omitted. The light-emitting element 19 may include a 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 is an independent electrode provided on each light-emitting element 19. The second electrode 15 may be a common electrode provided in common for a plurality of light-emitting elements 19.

[0046] The light generated by the light emitting element 19 passes through the second electrode 15 and is emitted from the light emitting device 2. Therefore, the second electrode 15 is formed of a transparent or semi-transparent layer. The second electrode 15 is formed of a thin film made of a metal material and may have a relatively high wiring resistance. If the light emitting element array 3 has a shape that is long in the X direction and the contact area 9 is arranged only along the longitudinal direction of the light emitting element array 3, a shadow occurs due to a voltage drop at the second electrode 15 (i.e., the brightness changes as the distance from the contact area 9 increases). As a countermeasure against such a problem, as in Figure 6 As shown in FIG. 1 as the contact region 9 a , the contact regions 9 whose number corresponds to the longitudinal length of the light emitting element array 3 can be arranged at appropriate positions in the longitudinal direction.

[0047] Figure 8 Schematically shows the Figure 6 The first moisture-proof ring 7 can be formed by stacking contact plugs and metal wiring, for example. The surface of the first moisture-proof ring 7 is covered with a protective layer 16 to inhibit moisture from invading the inner area (including the light-emitting element array 3) from the outside of the first moisture-proof ring 7.

[0048] Fig.15 Schematically shows the Figure 6 The cross section is taken along the line D-D'. Fig.15 An example of a light emitting element 23 and an example of a transistor 20 connected to the light emitting element 23 are schematically shown. The transistor 20 is an example of a functional element. The transistor 20 may be a thin film transistor (TFT).

[0049] The drain 25 and the source 24 of the transistor 20 are arranged on the material substrate 1. The gate 26 of the transistor 20 is arranged on the material substrate 1 via a gate insulating film (not shown).

[0050] The wiring 27 is composed of a plurality of contact plugs 21_1 to 21_4 and a plurality of metal wirings 22_1 to 22_4 that electrically connect the drain 25 of the transistor 20 to the light emitting element 23. An insulating layer 28 is provided between the wirings. Fig.15 The insulating layer 28 is shown as if it were a single layer, but the insulating layer 28 may have a multi-layer structure composed of a plurality of layers.

[0051] 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. Fig.15 The organic film 14 is shown as if it is a single layer, but the organic film 14 may be composed of multiple layers. In the light-emitting element 23, the organic film 14 is a transparent electrode, and light from the organic film 14 is extracted to the outside via the second electrode 15. A protective layer 16 is provided on the second electrode 15 to reduce degradation of the light-emitting element 23. The second electrode 15 of the light-emitting element 23 is shared by a plurality of light-emitting elements 23 and serves as a common electrode.

[0052] In the light emitting element array, the constituent unit composed of the combination of the light emitting element 23 and the transistor 20 can be repeatedly arranged in the row direction and the column direction. The scheme of electrically connecting the light emitting element 23 to the electrodes (source and drain) included in the transistor 20 is not limited to Fig.15 At least one of the source and the drain of the transistor 20 is electrically connected to the first electrode 13 of the light emitting element 23 according to the polarity of the first electrode 13 of the light emitting element 23 and the polarity of the transistor 20. Fig.15 Although a transistor is used as a switching element, another switching element may be used instead of the transistor.

[0053] In addition, 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 are single crystal silicon, non-single crystal silicon (such as amorphous silicon and microcrystalline silicon), and non-single crystal oxide semiconductors (such as indium zinc oxide and indium gallium zinc oxide).

[0054] In addition, the moisture-proof ring 7 is in physical contact with the protective layer 16 of the light-emitting element 23. This reduces or prevents moisture from intruding into the light-emitting element 23 from the outside. In addition, at least one of the plurality of contact plugs 21_1 to 21_4 and the plurality of metal wirings 22_1 to 22_4 forming the moisture-proof ring 7 may be partially replaced with a layer made of the same material as that of the protective layer 16. Since the protective layer 16 is formed of a material that can reduce moisture intrusion, the moisture-proof property of the moisture-proof ring 7 can be maintained even with such replacement. In the present embodiment, a structure having such replacement is also referred to as a moisture-proof ring.

[0055] exist Figure 6 In the example shown, the contact allowing area 10 with which the protrusion 6 of the deposition mask 4 contacts is provided at two locations. Figure 6 In the plan view (plan view) as shown, the moisture-proof wall 71 forming a part of the first moisture-proof ring 7 has recesses retreating from the first side S1 at two locations. The contact-allowed area 10 is arranged in these recesses. There are no components such as pads, drive circuits, and contact areas in the contact-allowed area 10. Enlarging the contact-allowed area 10 to the extent possible will narrow the protection area surrounded by the first moisture-proof ring 7 and reduce the possibility of defects occurring in the protection area, thereby improving the reliability of the light-emitting device 2. Note that an example of a defect that can occur in the protection area is moisture intrusion due to damage to the protective layer 16 on the protection area.

[0056] The pattern portion PP of the deposition mask 4 is configured to be separated from the material substrate 1 by the protrusion 6. If the gap between the pattern portion PP and the material substrate 1 (the height of the protrusion 6) is too large, a film having an overall range larger than the opening 5 of the pattern portion PP may be formed on the material substrate 1 by vapor deposition. Therefore, the gap between the pattern portion PP and the material substrate 1 (the height of the protrusion 6) is preferably 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 protrusion 6) can be determined in a manner that ensures that the pattern portion PP does not contact the material substrate 1.

[0057] The interval between adjacent protrusions 6 may also be considered. If the interval between adjacent protrusions 6 is too large, a portion of the pattern portion PP of the deposition mask 4 may contact the material substrate 1 between the protrusions 6. Table 1 exemplarily shows the results of checking whether the pattern portion PP is in contact with the material substrate 1 while changing the interval between the protrusions 6 and the thickness (layer thickness) of the pattern portion. The height of the protrusion 6 is set to 10 μm, the magnetic force used to fix the deposition mask 4 to the material substrate 1 is set to 150 Gauss, and the interval of the opening 5 is set to 250 μm. After the protrusion 6 of the deposition mask 4 contacts the material substrate 1, the particles on the area of ​​the material substrate 1 other than the contact allowing area 10 are measured by a particle counter, and the contact between the pattern portion PP and the material substrate 1 is evaluated. In this case, when there are no particles, "no contact" (NC) is determined, and when there are particles, "contact" (C) is determined.

[0058] [Table 1]

[0059]

[0060] Fig. 9 The configuration of a light-emitting device 2" according to a comparative example is shown. The light-emitting device 2" according to the comparative example has a rectangular moisture-proof ring 7. The contact-allowing area 10 is arranged on the outside of the moisture-proof ring 7. In this configuration, the dimension f of the unit composed of the light-emitting device 2" and the contact-allowing area 10 in the Y direction (second direction) is larger than the dimension e of the light-emitting device 2" in the Y direction. This reduces the number of light-emitting devices 2" obtained from one material substrate 1.

[0061] The manufacturing method for manufacturing the light emitting device 2 according to the first embodiment may have a deposition process of depositing a forming material of a functional layer on a material substrate 1 having a plurality of rectangular substrate regions each serving as a rectangular substrate RS by using a deposition mask 4. Each of the plurality of rectangular substrate regions of the material substrate 1 has a contact allowing region 10 between the first side S1 and a portion of the moisture-proof wall 71 defining the shortest distance d1. The deposition mask 4 may include a plurality of protrusions 6 respectively contacting the contact allowing 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 plurality of protrusions 6 define the distance between the material substrate 1 and the pattern portion PP.

[0062] The following will refer to Fig.10 A light emitting device 2 according to a second embodiment is described. Fig.10 The configuration of one light emitting device 2 according to the second embodiment is schematically shown. Note that matters not mentioned in the second embodiment may be in accordance with the first embodiment unless a contradiction occurs.

[0063] The light emitting device 2 may include a moisture-proof ring structure 70, which is arranged in the rectangular substrate RS in a manner to inhibit moisture from intruding into the light emitting element array 3 and all the pads 8. The moisture-proof ring structure 70 may include moisture-proof walls 71 and 72 arranged between the light emitting element array 3 and the first side S1. Fig.10 , the moisture-proof walls 71 and 72 of the moisture-proof ring structure 70 are represented by thick gray lines. The shortest distance between the light-emitting element array 3 and the moisture-proof walls 71 and 72 in the Y direction (the second direction) is the distance d1'. The distance between the light-emitting element array 3 and the moisture-proof wall 71 on the virtual straight line VSL is the distance d2, and the virtual straight line VSL is parallel to the Y direction (the second direction) and passes through the light-emitting element array 3 and the pad 8. In the second embodiment, the distance d1' is smaller than the distance d2. This reduces the distance (interval) between adjacent light-emitting devices 2 on the material substrate 1 in the Y direction, and increases the number of light-emitting devices 2 that can be formed on the material substrate 1, thereby helping to reduce the manufacturing cost of the light-emitting device 2.

[0064] The moisture-proof ring structure 70 may include a first moisture-proof ring 7 and a second moisture-proof ring 11, wherein the first moisture-proof ring 7 is configured to surround the light-emitting element array 3 and the pad 8, and the second moisture-proof ring 11 is configured to not surround the light-emitting element array 3 and the pad 8 and to be surrounded by the first moisture-proof ring 7. The first moisture-proof ring 7 may include a portion defining a distance d2 between the light-emitting element array 3 and the moisture-proof walls 71 and 72 on a virtual straight line VSL. The second moisture-proof ring 11 may include a portion defining a shortest distance d1' between the light-emitting element array 3 and the moisture-proof walls 71 and 72. The first moisture-proof ring 7 may be configured to surround the light-emitting element array 3 and the pad 8 all around. The second moisture-proof ring 11 may be configured as a structure that surrounds the inside of the second moisture-proof ring 11 all around.

[0065] The following will refer to Fig.11 A light emitting device 2 according to a third embodiment is described. Fig.11 The configuration of one light emitting device 2 according to the third embodiment is schematically shown. Note that matters not mentioned in the third embodiment may be in accordance with the first and second embodiments as long as no contradiction occurs.

[0066] The light emitting device 2 may include a moisture-proof ring structure 70, which is arranged in the rectangular substrate RS in a manner to inhibit moisture from intruding into the light emitting element array 3 and all the pads 8. The moisture-proof ring structure 70 may include moisture-proof walls 71 and 72 arranged between the light emitting element array 3 and the first side S1. Fig.11 The moisture-proof walls 71 and 72 of the moisture-proof ring structure 70 are indicated by thick gray lines. The shortest distance between the light-emitting element array 3 and the moisture-proof walls 71 and 72 in the Y direction (second direction) is the distance d1'. Fig.11In the case shown, the shortest distance between the light emitting element array 3 and the moisture-proof wall 71 in the Y direction (second direction) and the shortest distance between the light emitting element array 3 and the moisture-proof wall 72 in the Y direction (second direction) are both distance d1'. However, at least one of the shortest distance between the light emitting element array 3 and the moisture-proof wall 71 in the Y direction (second direction) and the shortest distance between the light emitting element array 3 and the moisture-proof wall 72 in the Y direction (second direction) can be distance d1'. The distance between the light emitting element array 3 and the moisture-proof wall 71 on the virtual straight line VSL parallel to the Y direction (second direction) and passing through the light emitting element array 3 and the pad 8 is distance d2. In the third embodiment, the distance d1' is less than the distance d2. This reduces the distance (interval) between adjacent light emitting devices 2 on the material substrate 1 in the Y direction, and increases the number of light emitting devices 2 that can be formed on the material substrate 1, thereby helping to reduce the manufacturing cost of the light emitting device 2.

[0067] The moisture-proof ring structure 70 may include a first moisture-proof ring 7 and a second moisture-proof ring 11, wherein the first moisture-proof ring 7 is configured to surround the light-emitting element array 3 and the pad 8, and the second moisture-proof ring 11 is configured to not surround the light-emitting element array 3 and the pad 8 and to be surrounded by the first moisture-proof ring 7. The first moisture-proof ring 7 may include a portion defining a distance d2 between the light-emitting element array 3 and the moisture-proof walls 71 and 72 on a virtual straight line VSL. At least one of the first moisture-proof ring 7 and the second moisture-proof ring 11 may include a portion defining a shortest distance d1' between the light-emitting element array 3 and the moisture-proof walls 71 and 72. The first moisture-proof ring 7 may be configured to surround the light-emitting element array 3 and the pad 8 all around. The second moisture-proof ring 11 may be configured as a structure that surrounds all around the inside of the second moisture-proof ring 11.

[0068] 16 to Fig.21 A light emitting device 402 according to a fourth embodiment is described. Note that matters not mentioned in the fourth embodiment may be in accordance with at least one of the first to third embodiments unless there is a contradiction. Unless otherwise explicitly stated, numerical values, shapes, materials, components, placement and connection forms of components, etc. are not intended to limit the scope of the disclosure.

[0069] OLED will be exemplarily described as a light emitting element. Note that the present disclosure is not limited to OLED and can be generally applied to current-driven light emitting devices.

[0070] Fig.16AThe case where the light emitting device 402 according to the fourth embodiment is formed on a material substrate 401 such as a silicon wafer is shown. The light emitting device 402 can form a matrix pattern on the substrate 401. In the case of a rectangular light emitting device 402, since the yield on one material substrate 401 varies greatly depending on the size in the short side direction, minimizing the size in the short side direction can effectively reduce costs. If a silicon wafer is used as a substrate for manufacturing the light emitting device 402, the drive circuit can be finely manufactured. This can increase the density of the OLED. Increasing the density can form an image with higher resolution.

[0071] Fig. 16B An example of a deposition mask 403 for forming an OLED on a light-emitting device 402 is shown. A plurality of openings 404 are arranged in the deposition mask 403. The arrangement interval of the plurality of openings 404 is equal to the arrangement interval of the plurality of light-emitting devices 402. After the light-emitting devices 402 on the material substrate 401 are stacked on the openings 404 of the deposition mask 403 in a plan view, the material substrate 401 is brought into close contact with the ribs 405 of the deposition mask 403, and electrodes and organic layers are deposited on the light-emitting devices by a vacuum deposition method, thereby forming an OLED.

[0072] Fig. 16C An example of a cross-sectional structure when the material substrate 401 is brought into close contact with the ribs 405 of the deposition mask 403 is shown. When the material substrate 401 is brought into close contact with the ribs 405 of the deposition mask 403, the ribs 405 of the deposition mask 403 enable the interval between the material substrate 401 and the pattern portion (a portion other than the ribs 405) of the deposition mask 403 to be maintained constant. In addition, the ribs 405 can minimize the area of ​​the deposition mask 403 in contact with the light emitting device 402, and prevent the transfer of foreign matter to the light emitting device 402 and the occurrence of defects, thereby preventing the occurrence of sealing failure.

[0073] Fig.17 4 is a cross-sectional schematic diagram showing an example of an OLED 420 and a transistor 414 connected to the OLED 420. The transistor is an example of a functional element. The transistor may be a thin film transistor (TFT). Fig.17 An OLED 420 and a transistor 414 are shown. A drain 412 and a source 411 of the transistor 414 are arranged in a silicon substrate 410. A gate 413 of the transistor 414 is arranged on the silicon substrate 410 via a gate insulating film (not shown).

[0074] The wiring 417 is composed of 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 to the OLED 420. An insulating layer 419 is provided between the wirings. Fig.17The insulating layer 419 is shown as if it were a single layer, but the insulating layer 419 may have a multi-layer structure composed of a plurality of layers.

[0075] 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. Fig.17 The organic film 421 is shown as if it is a single layer, but the organic film 421 may be composed of a plurality of 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 via the second electrode 422. A protective layer 425 is provided on the second electrode 422 to reduce degradation of the OLED 420. The second electrode 422 of the OLED 420 is shared by a plurality of OLEDs 420 and serves as a common electrode.

[0076] In the light emitting device 402, a constituent unit composed of a combination of an OLED 420 and a transistor 414 is repeatedly arranged in the row direction and the column direction. A structure 427 having a large step portion may be formed on a layer immediately below the organic film 421 between the respective OLEDs 420. Using the structure 427, a second electrode 422 for providing electrical connection may be formed when the organic film 421 is electrically isolated. The scheme of electrically connecting the OLED 420 to the electrodes (source and drain) included in the transistor 414 is not limited to Fig.17 At least one of the source and the drain of the transistor 414 is electrically connected to the first electrode 416_4 of the OLED 420 according to the polarity of the OLED 420 and the first electrode 416_4 and the polarity of the transistor 414. Fig.17 Although a transistor is used as a switching element, another switching element may be used instead of the transistor.

[0077] In addition, the transistor is not limited to a transistor formed on a single crystal silicon wafer, and may be a thin film transistor having an active layer on an insulating surface of a substrate. Examples of the active layer are single crystal silicon, non-single crystal silicon (such as amorphous silicon and microcrystalline silicon), and non-single crystal oxide semiconductors (such as indium zinc oxide and indium gallium zinc oxide).

[0078] Fig.18 1 is a schematic diagram showing one form of a light emitting device 402 according to the fourth embodiment. The light emitting device 402 according to the fourth embodiment has a rectangular shape with long sides parallel to a first direction and short sides parallel to a direction intersecting the first direction.

[0079] In the light emitting device 402, when the light emitting region 102 is formed along the long side direction, in the peripheral region of the light emitting region 102, components other than the light emitting region 102 such as a contact region can be arranged in a region adjacent to the light emitting region 102 along the short side direction.

[0080] The substrate 101 has a rectangular shape. In this specification, the long side direction of the rectangular substrate 101 is referred to as the first direction, and the short side direction orthogonal to the long side direction is referred to as the second direction. A moisture-proof ring 100 for preventing moisture from intruding into the light-emitting device 402 is configured on the rectangular substrate 101. In addition, in the area surrounded by the moisture-proof ring 100, a light-emitting area 102, a first contact area 103_1, a second contact area 103_2, and pads 104_1 and 104_2 are configured. A plurality of light-emitting elements are configured in the light-emitting area 102 along a matrix direction. The first contact area 103_1 and the second contact area 103_2 are areas where wiring electrically connected to a common electrode of the OLED is configured. The pads 104_1 and 104_2 are electrically connected to the contact areas.

[0081] In the light emitting region 102, a plurality of light emitting elements are arranged in a matrix pattern. As described above, each light emitting element includes a light emitting layer and a first electrode and a second electrode sandwiching the light emitting layer. The first electrode is an independent electrode provided for each light emitting element, and the second electrode is a common electrode provided for each light emitting element.

[0082] The first contact region 103_1 and the second contact region 103_2 are adjacent regions of the light emitting region 102 of the substrate 101, and are provided in a region surrounded by the moisture proof ring 100. The recess 105, the first contact region 103_1, the second contact region 103_2, and the pads 104_1 and 104_2 are arranged between the light emitting region 102 and one long side end of the substrate 101. In other words, when viewed from the light emitting region 102, the recess 105, the first contact region 103_1, the second contact region 103_2, and the pads 104_1 and 104_2 may be arranged in a short side direction. The recess 105 may be arranged between the first contact region 103_1 and the second contact region 103_2. The recess 105, the first contact region 103_1, the second contact region 103_2, and the pads 104_1 and 104_2 are arranged in a string along the long side direction. Fig.18 In the illustrated case, 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 sequentially arranged in a string along the longitudinal direction.

[0083] The moisture-proof ring 100 is a protective ring formed by a wiring layer and is arranged in a manner to surround the light-emitting area 102, the first contact area 103_1, the second contact area 103_2, and the pads 104_1 and 104_2. The moisture-proof ring 100 may have one or more recesses 105 along one long side of the substrate. The moisture-proof ring 100 may have a narrow portion 100_2 and wide portions 100_1 and 100_3 respectively arranged on both sides of the narrow portion 100_2 in the long side direction (first direction). 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. 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 long side of the narrow portion 100_2 in the short side direction may be consistent with the position of one long side of each wide portion 100_1 and 100_3 in the short side direction, while the positions of their other long sides in the short side direction may be different from each other. Due to the presence of the narrow portion 100_2, a recess is provided in the periphery of the moisture-proof ring 100. In the present embodiment, the portion is referred to as a recess 105. The recess 105 may be used as an abutment area for abutting against a rib 405 as a part of a deposition mask 403 in a deposition process. The width of the narrow portion 100_2 in the short side direction may be shorter than that of the wide portions 100_1 and 100_3 by an amount corresponding to the width of the recess 105 in the short side direction. The first contact area 103_1 and the second contact area 103_2 are respectively arranged inside the wide portions 100_1 and 100_3 of the moisture-proof ring 100.

[0084] A driving circuit (not shown) for the light-emitting device 402 may be formed inside the moisture-proof ring 100. When forming an OLED, the rib 405 of the deposition mask 403 contacts the recess 105 of the moisture-proof ring 100, in other words, contacts the outside of the moisture-proof ring 100 at the narrow portion 100_2 to maintain a constant distance between the deposition mask 403 and the pattern portion. The rib 405 is used to minimize the area in which the deposition mask 403 contacts the light-emitting device 402, prevent the transfer of foreign matter to the light-emitting device 402 and the occurrence of defects, and prevent the occurrence of sealing failure. If the rib 405 contacts the substrate, defects may occur in the insulating film on the substrate, and the sealing performance of the light-emitting device 402 is reduced. In this embodiment, the sealing performance of the light-emitting device 402 is ensured by configuring the recess 105 as the abutment area of ​​the rib 405 on the outside of the moisture-proof ring.

[0085] The second electrode (upper electrode / common electrode) 422 of each OLED according to the present embodiment is formed of a transparent electrode material and therefore has a relatively high wiring resistance. In addition, since the second electrode 422 is a common electrode, current flows into the electrode from multiple OLEDs, resulting in a large voltage drop at the second electrode 422. This causes the voltage applied to each OLED to differ depending on the distance from the contact area providing the potential. This sometimes causes a difference in actual light emission brightness between OLEDs to which a voltage for light emission at the same brightness level is applied, causing shadows, etc.

[0086] The light-emitting device 402 according to the present embodiment may have at least two contact regions (contact regions 103_1 and 103_2) to the second electrode (upper electrode / common electrode) 422 and a power supply wiring along the end of the long side of the light-emitting device 402. Making the second electrode 422 contact with the power supply wiring having a low resistance at multiple positions in the long side direction can reduce the voltage drop at the second electrode 422. Therefore, even if a plurality of OLEDs have a common second electrode 422, the voltage drop depending on the position of the second electrode 422 can be suppressed and the shadow of the light emission brightness can be suppressed.

[0087] The abutment area of ​​the first contact area 103_1 or the second contact area 103_2 and the rib 405 of the deposition mask 403 may be arranged in a series along the short side direction of the light emitting device 402. However, in this case, the area dedicated to the rib is set between the light emitting devices 402 along the short side direction, so the size of the light emitting device 402 increases by an amount corresponding to the rib dedicated area. The light emitting device 402 according to the present embodiment has a recess 105 as a moisture-proof ring of the rib abutment area arranged between the first contact area 103_1 and the second contact area 103_2. This can reduce the distance between the light emitting devices 402 in the short side direction. Therefore, the number and yield of the light emitting devices 402 in one substrate along the short side direction can be increased.

[0088] Fig.19 It is along Fig.18 4. The moisture-proof ring 100_2 has a multilayer structure formed by stacking contact plugs 445_1 to 445_4 and metal wirings 446_1 to 446_4, and extends from the surface of the light-emitting device 402 to a depth reaching the silicon substrate 410 forming the loop element. The contact plugs 445_1 to 445_4 and the metal wirings 446_1 to 446_4 forming the moisture-proof ring 100_2 are formed by the same layers as the contact plugs 415_1 to 415_4 and the metal wirings 416_1 to 416_4 forming the wiring 417. As described above, the moisture-proof ring 100_2 has the same layer structure as the multilayer wiring structure of the internal loop, and can be formed simultaneously with the internal loop in a common process.

[0089] The cross-sectional structure of the moisture-proof ring 100_1 may have the same structure as that of the moisture-proof ring 100_2 at any position of the light-emitting device 402 .

[0090] The moisture-proof rings 100_1 and 100_2 are in physical contact with the protection layer 425 of the OLED 420 and serve to prevent moisture from intruding into the OLED 420 .

[0091] In the scratch region 441 , the protective layer 425 of the light emitting device 402 is removed. This makes it possible to prevent cracks in the protective layer 425 when the light emitting device 402 is cut off from the silicon substrate 410.

[0092] In the contact region 103_1, the second electrode (common electrode) 422 of the OLED 420 is in physical contact with the metal wiring 456_4. The pad 104_1 is formed by a metal wiring of the same layer as the layer of the metal wiring 456_3. In this structure, the metal wiring 456_3 with low resistance extends from the pad 104_1 to just below the contact region 103_1, and the contact plug 455_4 provides electrical continuity with low resistance between the metal wiring 456_3 and the metal wiring 456_4. In the present embodiment, the pad 104_1 is the same layer as the metal wiring 456_3. However, for example, the pad 104_1 may be a wiring of the same layer as the layer of the metal wiring 456_4.

[0093] With the configuration described in this embodiment mode, it is possible to obtain the effects of improving the yield and manufacturing the light-emitting device 402 at low cost while suppressing brightness shading in the light-emitting device 402.

[0094] The following will refer to Fig. 20 A light emitting device 402 according to a fifth embodiment will be described. Note that matters not mentioned in the fifth embodiment may be applied to the fourth embodiment unless there is any inconsistency. Fig. 20 is a schematic diagram showing the configuration of a light emitting device according to a fifth embodiment.

[0095] A moisture-proof ring 200 , a light-emitting region 102 having light-emitting pixels arranged in a matrix direction, 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 are arranged on a rectangular substrate 101 .

[0096] In the present embodiment, the moisture-proof ring 200 is formed 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 width of the narrow portions 200_2, 200_4, 200_6, and 200_8 in the short side direction is shorter than the width of the wide portions 200_1, 200_3, 200_5, 200_7, and 200_9 in the short side direction. The following is an example of forming four narrow portions. However, the number of narrow portions is not limited to this number.

[0097] Due to the presence of wide portions 200_1, 200_3, 200_5, 200_7 and 200_9, the outer peripheral shape of the moisture-proof ring 200 includes a plurality of recesses. These portions are referred to as recesses 205_1 to 205_4 of the moisture-proof ring. Recesses 205_1 to 205_4 can be used as abutment areas for abutment of ribs as part of a deposition mask in a deposition process. In the present embodiment, recesses 205_1 to 205_4 of the moisture-proof ring 200 are configured along the long sides of the light-emitting device. This configuration makes it possible to reduce the configuration interval of the rib abutment area on the substrate 101 and suppress the deflection of the deposition mask. In addition, reducing the configuration interval of the rib abutment area can shorten the length in the long side direction of each recess as an abutment area, and reduce the interval between the first contact area and the second contact area. Therefore, the resistance of the common electrode in the middle part of the light-emitting device can be further reduced and the brightness shadow in the light-emitting device can be suppressed. Alternatingly arranging the common electrode, the contact regions 203_1 to 203_3 of the power wiring, and the recessed portions 205_1 to 205_3 of the moisture-proof ring can reduce the resistance of the common electrode at multiple locations.

[0098] The light emitting device can be further miniaturized by arranging components such as contact regions other than the light emitting region of the light emitting device along the long side direction. This makes it possible to improve the yield on the substrate and reduce costs. In this specification, the components A and B are arranged in a series along the first direction, which means that there is a portion where the components A and B are stacked on each other in a plan view from the first direction with respect to a plane perpendicular to the first direction.

[0099] The following will refer to Fig.21 A light emitting device 402 according to a sixth embodiment will be described. Note that matters not mentioned in the sixth embodiment may be applied to the fifth embodiment unless there is any contradiction. Fig.21 is a schematic diagram showing the configuration of a light emitting device according to a sixth embodiment. Fig. 20Compared with the light-emitting device in FIG. 1 , loops 206_1 and 206_2 for driving the light-emitting elements are added. The loops 206_1 and 206_2 are arranged in a series along the long side direction. In other words, with respect to a plane perpendicular to the long side direction, the loops 206_1 and 206_2 are additionally arranged in a manner stacked on each other in a plan view. In addition, the loops 206_1 and 206_2 are arranged in a series along the long side direction together with the contact areas 203_1 to 203_3 and the pads 204_1 to 204_3.

[0100] Specific examples of the loops 206_1 and 206_2 are an input protection loop, an input loop for inputting each driving data, and a logic loop for processing data. However, this is not limited. By setting the loop area at the same position as the contact area and the pad area in the short side direction and configuring the loop in the loop area, the length of the light emitting device in the short side direction can be reduced.

[0101] Fig. 22 It is along Fig.21 A cross-sectional view taken along line F-F' in the light emitting device of FIG. By adding loops 206_1 and 206_2 to Fig.19 The structure in is obtained.

[0102] With the configuration described in this embodiment mode, brightness shadows of the light-emitting device can be effectively suppressed.

[0103] Will refer to Fig.12 An imaging device 1100 is exemplarily described in which the light emitting device 2 represented by the first to third embodiments is assembled. Fig.12 The configuration of the imaging device 1100 is schematically shown. The imaging device 1100 can be configured as an electrophotographic imaging device. The imaging device 1100 may include a photoreceptor 1101, a charging unit 1102 for charging the photoreceptor 1101, an exposure unit 1103 for exposing the surface of the photoreceptor 1101 to form an electrostatic latent image on the surface, and a developing unit 1104 for developing the electrostatic latent image. The exposure unit 1103 may include the light emitting device 2 described above as a light source. The developing unit 1104 may form an image by attaching a toner to the electrostatic latent image. The imaging device 1100 may also include a transfer unit 1105 for transferring the image formed by the developing unit 1104 to a recording medium 1107 and a fixing unit 1106 for fixing the image transferred to the recording medium 1107.

[0104] Reference Fig.12, the X direction is expressed as a column (the arrangement direction thereof), and the Y direction is expressed as a row (the arrangement direction thereof). In this case, the X direction may be a direction along the rotation axis direction of the photosensitive body 1101 of the imaging device 1100. A plurality of light emitting devices 2 may be arranged to form a light source for the exposure unit 1103. For example, Fig.13 As exemplarily shown in FIG. 1 , a plurality of light emitting devices 2 may be configured in a staggered configuration. The light emitting elements in each light emitting element array 3 may be configured in a row, or may be configured to form a plurality of rows. Configuring the light emitting elements to form a plurality of rows in each light emitting element array 3 is advantageous for color tone expression, and is also advantageous for reducing the amount of light emitted by each light emitting element and increasing the service life of the light emitting element. Assume that the light emitting elements are configured to form a plurality of rows in each light emitting element array 3. In this case, as Fig.14 As exemplarily shown in FIG. 1 , if there are four rows of light emitting elements, the position of the first light emitting element in the first row and the position of the first light emitting element in the second row may be staggered in the X direction by 1 / 4 of the X-direction size of the light emitting element. In the case of n rows, the position of the first light emitting element in the first row and the position of the first light emitting element in the second row may be staggered in the X direction by 1 / n of the X-direction size of the light emitting element. This configuration is conducive to improving resolution.

[0105] The details of each constituent element of the light emitting device 2 will be exemplarily described below.

[0106] [Configuration of organic light emitting elements]

[0107] An 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. If a color filter is provided, a planarization layer may be provided between the protective layer and the color filter. The planarization layer may be made of an acrylic resin, etc. The same applies to the case where a planarization layer is provided between the color filter and the microlens.

[0108] [Substrate]

[0109] Quartz, glass, silicon wafer, resin, metal, etc. can be used as the substrate. In addition, switching elements such as transistors and wiring can be provided on the substrate, and an insulating layer can be provided on the substrate. The insulating layer can be made of any material as long as the contact hole can be formed so that wiring can be formed between the insulating layer and the first electrode and insulation from unconnected wiring is ensured. For example, resins such as polyimide, silicon oxide, silicon nitride, etc. can be used.

[0110] [electrode]

[0111] A pair of electrodes may be used as the electrode. The pair of electrodes may be an anode and a cathode. If an electric field is applied in the direction in which the organic light-emitting element emits light, the electrode with a high potential is the anode, and the other is the cathode. It can also be said that the electrode that provides holes to the light-emitting layer is the anode, and the electrode that provides electrons is the cathode.

[0112] As the constituent material of the anode, it is preferred to use a material having a work function as large as possible. For example, metals such as gold, platinum, silver, copper, nickel, palladium, cobalt, selenium, vanadium or tungsten can be used. Alternatively, a mixture containing some of them, an alloy obtained by combining some of them, or a metal oxide such as tin oxide, zinc oxide, indium oxide, indium tin oxide (ITO) or zinc indium oxide can be used. In addition, conductive polymers such as polyaniline, polypyrrole or polythiophene can also be used.

[0113] One of these electrode materials may be used alone, or two or more of them may be used in combination. The anode may be formed of a single layer or a multilayer.

[0114] If the anode is used as a reflective electrode, for example, chromium, aluminum, silver, titanium, tungsten, molybdenum, their alloys, their stacked layers, etc. can be used. The above materials can be used as a reflective film without acting as an electrode. If the anode is used as a transparent electrode, an oxide transparent conductive layer made of indium tin oxide (ITO), indium zinc oxide, etc. can be used, but the present invention is not limited thereto. Photolithography technology can be used to form the electrode.

[0115] On the other hand, it is preferred to use a material with a smaller work function as a constituent material of the cathode. Examples of materials include alkali metals such as lithium, alkaline earth metals such as calcium, metals such as aluminum, titanium, manganese, silver, lead or chromium, and mixtures containing some of them. Alternatively, alloys obtained by combining these metals can also be used. For example, magnesium-silver alloys, aluminum-lithium alloys, aluminum-magnesium alloys, silver-copper alloys, zinc-silver alloys, etc. can be used. Metal oxides such as indium tin oxide (ITO) can also be used. One of these electrode materials can be used alone, or two or more of them can be used in combination. The cathode can be a single-layer structure or a multilayer structure. Among other things, silver is preferably used. In order to suppress the aggregation of silver, a silver alloy is more preferably used. The ratio of the alloy is not limited as long as the aggregation of silver can be suppressed. For example, the ratio between silver and other metals can be 1:1, 3:1, etc.

[0116] The cathode may be a top emission element using an oxide conductive layer made of ITO or the like, or may be a bottom emission element using a reflective electrode made of aluminum (Al) or the like, and is not particularly limited. The method of forming the cathode is not particularly limited, but DC sputtering or AC sputtering is preferably used because good film coverage is provided and resistance is easily reduced.

[0117] [Pixel Isolation Layer]

[0118] The pixel isolation layer is formed by a silicon nitride (SiN) film, a silicon oxynitride (SiON) film, or a silicon oxide (SiO) film formed by a chemical vapor deposition method (CVD method). In order to increase the resistance of the organic film in the in-plane direction, the organic film, especially the hole transport layer, is preferably deposited thinly on the side wall of the pixel isolation layer. More specifically, by increasing the taper angle of the side wall of the pixel isolation layer or the film thickness of the pixel isolation layer to increase the vignetting during vapor deposition, the organic compound layer can be deposited in a manner having a thin film thickness on the side wall.

[0119] On the other hand, it is preferred that the taper angle of the side wall of the pixel isolation layer or the film thickness of the pixel isolation layer is adjusted to such an extent that no space is formed in the protective layer formed on the pixel isolation layer. Since no space is formed in the protective layer, the generation of defects in the protective layer can be reduced. Since the generation of defects in the protective layer is reduced, the reduction in reliability caused by the generation of dark spots or the occurrence of conductive failure of the second electrode can be reduced.

[0120] According to this embodiment, even if the taper angle of the side wall of the pixel isolation layer is not steep, the leakage of charge to adjacent pixels can be effectively suppressed. As a result of this consideration, it has been found that a taper angle of 60° (inclusive) to 90° (inclusive) can sufficiently reduce the occurrence of defects. The film thickness of the pixel isolation layer is desirably 10nm (inclusive) to 150nm (inclusive). The same effect can be obtained in a configuration including only a pixel electrode without a pixel isolation layer. However, in this case, because the short circuit of the organic light-emitting element can be reduced, the film thickness of the pixel electrode is preferably set to be equal to or less than half the film thickness of the organic layer, or the end of the pixel electrode is preferably formed to have a forward taper of less than 60°.

[0121] [Organic film]

[0122] The organic film may be formed by a single layer or multiple layers. If the organic film includes multiple layers, the layers may be referred to as hole injection layers, hole transport layers, electron blocking layers, light emitting layers, hole blocking layers, electron transport layers, and electron injection layers, depending on the functions of the layers. The organic film is mainly formed of organic compounds, but may contain inorganic atoms and inorganic compounds. For example, the organic film 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, and may be configured to contact the first electrode and the second electrode.

[0123] If the organic film has a plurality of light-emitting layers, the film may have a charge generation unit between the first light-emitting layer and the second light-emitting layer. The charge generation unit may have an organic compound having a lowest unoccupied molecular orbital energy (LUMO) of 5.0 eV or less. The same applies to the case where the organic film has a charge generation unit between the second light-emitting layer and the third light-emitting layer.

[0124] [Protective layer]

[0125] A protective layer may be provided on the second electrode. For example, by attaching a glass provided with a moisture absorbent on the second electrode, water or the like may be inhibited from intruding into the organic film, and the occurrence of display defects may be inhibited. In addition, as another embodiment, a passivation film made of silicon nitride or the like may be provided on the cathode to inhibit water or the like from intruding into the organic film. For example, a protective layer may be formed by forming a cathode, transferring the cathode to another chamber without breaking the vacuum, and forming a silicon nitride film having a thickness of 2 μm by a CVD method. After deposition using the CVD method, an atomic deposition method (ALD method) may be used to provide a protective layer. The material of the film formed by the ALD method is not limited, but may be silicon nitride, silicon oxide, aluminum oxide, or the like. A silicon nitride film may be further formed by a CVD method on the film formed by the ALD method. The film formed by the ALD method may have a film thickness that is smaller than the film thickness of the film formed by the CVD method. More specifically, the film thickness of the film formed by the ALD method may be 50% or less or 10% or less.

[0126] [Color Filter]

[0127] A color filter may be provided on the protective layer. For example, a color filter that takes into account the size of the organic light-emitting element may be provided on another substrate, and the substrate may be bonded to the substrate on which the organic light-emitting element is provided. Alternatively, a color filter may be patterned on the protective layer using photolithography. The color filter may be formed of a polymer material.

[0128] [Planarization layer]

[0129] A planarization layer may be provided between the color filter and the protective layer. The planarization layer is provided to reduce the concavity and convexity of the lower layer. Without limiting the purpose of the planarization layer, the planarization layer may be referred to as a material resin layer. The planarization layer may be formed of an organic compound and may be made of a low molecular weight material or a polymer material. However, a polymer material is more preferred.

[0130] A planarization layer may be provided above and below the color filter, and the same or different materials may be used for them. More specifically, examples of the material include polyvinyl alcohol carbazole resin, polycarbonate resin, polyester resin, ABS resin, acrylic resin, polyimide resin, phenol resin, epoxy resin, silicone resin, and urea resin.

[0131] [Microlens]

[0132] The organic light-emitting device may include optical components, such as a microlens on the light-emitting side. The microlens may be made of acrylic resin, epoxy resin, etc. The purpose of the microlens is to increase the amount of light extracted from the organic light-emitting device and to control the direction of the light to be extracted. The microlens may be in a hemispherical shape. If the microlens is in a hemispherical shape, among the tangents in contact with the hemisphere, there is a tangent parallel to the insulating layer, and the junction between the tangent and the hemisphere is the vertex of the microlens. Even in any cross-sectional view, the vertex of the microlens can be determined in the same way. That is, among the tangents of the semicircle that contacts the microlens in the cross-sectional view, there is a tangent parallel to the insulating layer, and the junction between the tangent and the semicircle is the vertex of the microlens.

[0133] In addition, the midpoint of the microlens can also be defined. In the cross section of the microlens, a line segment from a point where an arc shape ends to a point where another arc shape ends is assumed, and the midpoint of the line segment can be called the midpoint of the microlens. The cross section used to determine the vertex and the midpoint can be a cross section perpendicular to the insulating layer.

[0134] The microlens includes a first surface and a second surface, the first surface includes a convex portion, and the second surface is opposite to the first surface. The second surface is preferably configured on the functional layer side of the first surface. For this configuration, it is necessary to form the microlens on the light-emitting device. If the functional layer is an organic layer, it is preferred to avoid processes that generate high temperatures in the manufacturing steps. In addition, if it is configured to configure the second surface on the functional layer side of the first surface, all glass transition temperatures of the organic compounds forming the organic layer are preferably 100°C or higher, and more preferably 130°C or higher.

[0135] [Counter substrate]

[0136] A counter substrate may be disposed on the planarization layer. The counter substrate is called a counter substrate because it is disposed at a position corresponding to the above-mentioned substrate. The constituent material of the counter substrate may be the same as the constituent material of the above-mentioned substrate. If the above-mentioned substrate is the first substrate, the counter substrate may be the second substrate.

[0137] [Organic layer]

[0138] 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.) forming the organic light emitting element according to one embodiment of the present invention are formed by the following method.

[0139] The organic film forming the organic light-emitting element according to the embodiment of the present invention can be formed by using a dry process such as vacuum deposition, ionization deposition, sputtering, plasma, etc. Instead of the dry process, a wet process can be used by dissolving a solute in an appropriate solvent and forming a layer using a well-known coating method (e.g., spin coating, dipping, casting, LB method, inkjet method, etc.).

[0140] Here, when the layer is formed by a vacuum deposition method, a solution coating method, etc., crystallization or the like hardly occurs, and excellent temporal stability is obtained. In addition, when the layer is formed using a coating method, a film can be formed in combination with an appropriate binder resin.

[0141] Examples of the binder resin include polyvinyl alcohol carbazole resin, polycarbonate resin, polyester resin, ABS resin, acrylic resin, polyimide resin, phenol resin, epoxy resin, silicone resin, and urea resin. However, the binder resin is not limited thereto.

[0142] One of these binder resins may be used alone as a homopolymer or a copolymer, or two or more of them may be used in combination. In addition, additives such as known plasticizers, antioxidants, and ultraviolet absorbers may also be used as needed.

[0143] According to one aspect of the present disclosure, a technology is provided that is beneficial to reducing the manufacturing cost of a light emitting device having a moisture proof ring structure.

[0144] While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments.The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.

Claims

1. A light emitting device, comprising: A polygonal 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 orthogonal to the first direction; a light emitting element array having a plurality of light emitting elements arranged on the substrate; a pad, which is arranged on the substrate in a manner of being located between the first side and the light emitting element array; and A moisture-proof ring structure is arranged on the substrate, The moisture-proof ring structure includes a moisture-proof wall disposed between the light-emitting element array and the first side, and The shortest distance between the light emitting element array and the moisture-proof wall in the second direction is smaller than the distance between the light emitting element array and the moisture-proof wall on a virtual straight line parallel to the second direction and passing through the light emitting element array and the pad.

2. The light emitting device according to claim 1, wherein The moisture-proof ring structure includes a first moisture-proof ring configured to surround the light-emitting element array and the pad, and The moisture-proof wall is a part of the first moisture-proof ring.

3. The light emitting device according to claim 1, wherein: The moisture-proof ring structure includes a first moisture-proof ring configured to surround the light-emitting element array and the pad, and a second moisture-proof ring configured not to surround the light-emitting element array and the pad and to be surrounded by the first moisture-proof ring. The first moisture-proof ring includes a portion defining the distance between the light-emitting element array and the moisture-proof wall on the virtual straight line, and The second moisture-proof ring includes a portion defining the shortest distance between the light-emitting element array and the moisture-proof wall.

4. The light emitting device according to claim 1, wherein: The moisture-proof ring structure includes a first moisture-proof ring configured to surround the light-emitting element array and the pad, and a second moisture-proof ring configured not to surround the light-emitting element array and the pad and to be surrounded by the first moisture-proof ring. The first moisture-proof ring includes a portion defining the distance between the light-emitting element array and the moisture-proof wall on the virtual straight line, and At least one of the first moisture-proof ring and the second moisture-proof ring includes a portion defining the shortest distance between the light-emitting element array and the moisture-proof wall.

5. The light emitting device according to any one of claims 2 to 4, wherein: The first moisture-proof ring is arranged to surround the light-emitting element array entirely.

6. The light emitting device according to claim 3, wherein: The first moisture-proof ring is arranged to surround the light-emitting element array and the pads. The second moisture-proof ring is arranged so as to completely surround the structure arranged inside the second moisture-proof ring.

7. A light emitting device according to any one of claims 2 to 4, wherein: The size of the smallest rectangle circumscribed to the light emitting element array in the first direction is larger than that in the second direction.

8. A light emitting device according to any one of claims 2 to 4, wherein: Each of the plurality of light emitting elements includes a plurality of functional layers including organic materials.

9. The light emitting device according to any one of claims 2 to 4, further comprising a plurality of contact regions arranged on the polygonal substrate in a manner to receive signals or potentials for driving the plurality of light emitting elements, in, The moisture-proof ring structure is arranged on the polygonal substrate in a manner to suppress moisture from entering the plurality of contact regions in addition to the light emitting element array and the pads.

10. The light emitting device according to claim 9, wherein: The plurality of contact regions include a first contact region disposed between the light emitting element array and the first side.

11. The light emitting device according to claim 9, wherein: The plurality of contact regions further include 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.

12. The light emitting device according to claim 10, wherein: The portion of the moisture-proof wall that defines the shortest distance is arranged between the pad and the first contact area in the first direction.

13. The light emitting device according to any one of claims 2 to 4, further comprising a second pad arranged on the polygonal substrate in a manner of being located between the first side and the light emitting element array, and The portion of the moisture-proof wall that defines the shortest distance is arranged between the pad and the second pad in the first direction.

14. The light emitting device according to any one of claims 2 to 4, further comprising a trace of contact of a portion of a deposition mask for forming the plurality of light emitting elements between the moisture-proof wall and the first side.

15. An imaging device comprising: Photoreceptor; a charging unit configured to charge the photosensitive body; an exposure unit configured to expose a surface of the photoreceptor to form an electrostatic latent image on the surface; and a developing unit configured to develop the electrostatic latent image, Wherein, the exposure unit comprises the light emitting device defined in any one of claims 1 to 14.

16. A method for manufacturing a light emitting device, the method comprising: Prepare a polygonal substrate on which a light-emitting element array including a plurality of light-emitting elements, a solder pad, and a moisture-proof ring structure are arranged, wherein the polygonal substrate has 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 orthogonal to the first direction, and the moisture-proof ring structure is arranged on the polygonal substrate in a manner of surrounding the light-emitting element array and the solder pad; and depositing a forming material for a functional layer on the polygonal substrate by using the deposition mask in a state where a protrusion of the deposition mask is in contact with a contact allowing region located between the first side and a portion of the moisture-proof ring structure, The pads and the protrusions are located on a line along the first direction.

17. The method according to claim 16, wherein: The shortest distance between the light emitting element array and the moisture proof ring structure in the second direction is smaller than the distance between the light emitting element array and the moisture proof ring structure on a virtual straight line parallel to the second direction and passing through the light emitting element array and the pad.

18. The method according to claim 17, wherein: The moisture-proof ring structure includes a first moisture-proof ring configured to surround the light-emitting element array and the pad, and a second moisture-proof ring configured not to surround the light-emitting element array and the pad and to be surrounded by the first moisture-proof ring. The first moisture-proof ring includes a portion defining the distance between the light-emitting element array and the moisture-proof ring structure on the virtual straight line, and The second moisture-proof ring includes a portion defining the shortest distance between the light-emitting element array and the moisture-proof ring structure.

19. The method according to claim 17, wherein: A plurality of contact regions including a first contact region are arranged on the polygonal substrate in such a manner as to receive a signal or a potential for driving the plurality of light emitting elements, and The portion of the moisture-proof ring structure that defines the shortest distance is arranged between the pad and the first contact region in the first direction.

20. The method according to claim 18, wherein: The first moisture-proof ring is arranged to surround the light-emitting element array entirely.

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