阅读说明：本技术 有机el器件 (Organic EL device ) 是由 新山刚宏 井出慎司 江泽拓 于 2020-09-16 设计创作，主要内容包括：一种实施方式所涉及的有机EL器件(1)具备：元件基板(2)；元件(4),设置于元件基板(2)上；干燥剂(7),设置于元件基板(2)上并且覆盖元件(4)；及密封基板(3),与元件基板(2)对置配置并且密封元件(4)。在干燥剂(7)与密封基板(3)之间形成有空间部(10)。(An organic EL device (1) according to an embodiment includes: an element substrate (2); an element (4) provided on the element substrate (2); a drying agent (7) that is provided on the element substrate (2) and covers the element (4); and a sealing substrate (3) which is disposed so as to face the element substrate (2) and which seals the element (4). A space (10) is formed between the desiccant (7) and the sealing substrate (3).)

1. An organic EL device comprising:

an element substrate;

an element disposed on the element substrate;

a desiccant that is provided on the element substrate and covers the element; and

a sealing substrate arranged to face the element substrate and sealing the element,

a space is formed between the desiccant and the sealing substrate.

2. The organic EL device according to claim 1, wherein,

the sealing substrate is made of metal.

3. The organic EL device according to claim 1 or 2, wherein,

the thickness of the sealing substrate is 10 [ mu ] m or more and 100 [ mu ] m or less.

4. The organic EL device according to any one of claims 1 to 3, wherein,

the thickness of the space part is 5 [ mu ] m or more.

5. The organic EL device according to any one of claims 1 to 4, wherein,

the drying agent contains an alkaline earth metal and a curable resin.

Technical Field

The present invention relates to an organic EL device.

Background

Conventionally, an organic EL device using an organic EL material (EL: Electro-Luminescence) as a light-emitting substance is known. The organic EL device has an organic EL element. The organic EL element includes a pair of electrodes and an organic EL material sandwiched between the pair of electrodes. The organic EL element is sometimes affected by moisture. In an organic EL element, for example, the electrodes may be oxidized or peeled off due to adhesion of moisture. Therefore, in the organic EL device, various countermeasures for suppressing entry of moisture into the organic EL element are implemented.

Patent document 1 describes an organic electronic device using a water-capturing agent. The organic electronic device is provided with: an element substrate composed of a glass substrate; an element formed on the element substrate; a sealing substrate arranged to face the element substrate and covering the element; and a sealant for fixing the sealing substrate to the element substrate. The sealing substrate is formed of spot-faced glass. The sealing substrate is provided with a water-trapping agent in a recess formed by spot facing. In this manner, the organic electronic device includes the water-trapping agent provided in the recess of the sealing substrate. The organic electronic device has a hollow sealing structure in which the element is sealed in a state in which a space is formed between the element and the water-capturing agent on the element substrate.

Patent document 2 describes an organic EL device. The organic EL element includes: an element substrate; a sealing substrate arranged to face the element substrate; and a laminate which is provided on the element substrate and in which the organic layer is sandwiched between the pair of electrodes. The filler is filled between the laminate and the sealing substrate, and the sealing substrate is fixed to the element substrate via the sealant. The organic EL element has no space inside. The organic EL element has a filling and sealing structure in which the laminate is sealed in a state in which a filler functioning as a desiccant is filled therein.

Patent document 1: japanese patent laid-open publication No. 2012-38659

Patent document 2: japanese patent laid-open No. 2014-201574

The organic electronic device has a hollow sealing structure in which the element is sealed in a state in which a space is formed between the element and the water-capturing agent. In the hollow sealing structure, the elements on the element substrate are exposed in a space formed between the sealing substrate and the element substrate. Therefore, moisture that has entered the inside of the sealing substrate from the sealant directly adheres to the element, and thus the element cannot be sufficiently protected from the moisture.

The organic EL element has a filling and sealing structure for sealing the element in a state where a desiccant is filled therein. In the filling and sealing structure, moisture that has entered the inside of the sealing substrate from the sealant adheres to the desiccant, and therefore, direct adhesion of moisture to the element can be suppressed. However, in a filled seal structure, the effective area of the desiccant relative to moisture ingress from the sealant is small. That is, in the filled and sealed structure, the area of the desiccant for attaching moisture entering from the sealant is small. Therefore, there is a problem that the desiccant cannot be effectively used because water is trapped in a limited area of the desiccant.

In the filling and sealing structure, since water is trapped by a limited region of the desiccant, it is necessary to secure a wide region of the desiccant filled between the sealant and the element. Therefore, the space for filling the desiccant must be ensured to be large. The filling and sealing structure has the following structure: a space is not formed between the element and the sealing substrate, the desiccant, and the element are closely attached to each other. Therefore, when an external force is applied to the sealing substrate and the desiccant during bonding, the external force is transmitted to the element through the sealing substrate and the desiccant, and the element is easily damaged by the external force.

Disclosure of Invention

The invention aims to provide an organic EL device which can sufficiently protect an element from moisture, can sufficiently and effectively utilize a drying agent, and is not easily affected by an external force.

The organic EL device of the present invention includes: an element substrate; an element disposed on the element substrate; a desiccant disposed on the element substrate and covering the element; and a sealing substrate which is arranged to face the element substrate and seals the element, and a space is formed between the desiccant and the sealing substrate.

In the organic EL device, an element provided on an element substrate is covered with a desiccant. Therefore, the moisture that has entered the inside of the sealing substrate adheres to the desiccant, and the element can be protected from the moisture. That is, since the element is covered with the desiccant, it is possible to prevent moisture from directly adhering to the element, and thus it is possible to sufficiently protect the element from moisture. A space is formed inside the sealing substrate, and the space is provided between the desiccant and the sealing substrate. Therefore, by exposing the desiccant to the space portion inside the sealing substrate, the area of the desiccant to which the moisture has adhered can be ensured to be large, and therefore the desiccant can be sufficiently utilized. Further, since a sufficient water-trapping effect can be obtained with a small amount of the desiccant, the space for installing the desiccant can be reduced. Further, by forming the space between the sealing substrate and the drying agent, it is possible to make it difficult for external force applied to the sealing substrate to be transmitted to the drying agent and the element, and therefore it is possible to improve resistance against the external force. Therefore, it can be made less susceptible to external force.

The sealing substrate may be made of metal. In this case, it is possible to make it difficult for water to flow through the sealing substrate to the inside, and to improve the strength of the sealing substrate. Further, since the sealing substrate made of metal has flexibility, resistance against bending can be improved. Further, in the case where the sealing substrate is made of metal, the inner surface of the sealing substrate can be formed by drawing (drawing) processing, and therefore, the cost required for processing and the like can be reduced.

The thickness of the sealing substrate may be 10 μm or more and 100 μm or less. In this case, since the strength of the sealing substrate can be ensured by setting the thickness of the sealing substrate to 10 μm or more, it is possible to avoid forming a hole in the sealing substrate when processing or the like is performed. By setting the thickness of the sealing substrate to 100 μm or less, the sealing substrate can be prevented from becoming excessively hard, and therefore the processing of the sealing substrate can be easily performed.

The thickness of the space portion may be 5 μm or more. In this case, by setting the thickness of the space portion to 5 μm or more, the moisture entering the inside of the sealing substrate can be sufficiently diffused in the space portion. Therefore, the desiccant can be used to capture water more reliably, and the desiccant can be used more effectively. By setting the thickness of the space portion to 5 μm or more, the external force can be more hardly transmitted to the desiccant and the element, which contributes to further improvement in strength.

The drying agent may contain an alkaline earth metal and a curable resin. In this case, the drying agent can be cured by including a curable resin in the drying agent. By including the alkaline earth metal in the desiccant, the water trapping property as the desiccant against the moisture entering the inside of the sealing substrate can be improved. Moreover, the life of the desiccant can be extended.

Effects of the invention

According to the present invention, the element can be sufficiently protected from moisture, the desiccant can be sufficiently effectively used, and the element is less susceptible to external force.

Drawings

Fig. 1 is a diagram schematically showing an organic EL device according to an embodiment.

Fig. 2 is a cross-sectional view showing an element substrate, an element, a drying agent, and a sealing substrate of the organic EL device of fig. 1.

Fig. 3 is a sectional view taken along line iii-iii of fig. 2.

In the figure: 1-organic EL device, 2-element substrate, 2 b-long side, 2 c-short side, 2D-main side, 2 f-edge region, 3-sealing substrate, 3 b-main side, 3 c-concave portion, 3D-long side, 3 f-short side, 3 g-long side, 3 h-short side, 3 j-corner, 4-element, 4 b-organic EL element, 5-wiring portion, 6-adhesive, 6 b-inner surface, 7-desiccant, 7 b-side, 7 c-side, 7D-portion, 8-integrated circuit, 9-FPC, 10-space portion, 11-1 st space portion, 12-2 nd space portion, 13-3 rd space portion, A-region, D1-stacking direction, d2-1 st direction, D3-2 nd direction, L-path, M-moisture, W-width.

Detailed Description

Hereinafter, embodiments of the organic EL device according to the present invention will be described with reference to the drawings. In the description of the drawings, the same or corresponding elements are denoted by the same reference numerals, and overlapping description is appropriately omitted. For easy understanding, a part of the drawings may be drawn in a simplified or exaggerated manner, and the dimensional ratio and the like are not limited to those shown in the drawings.

The organic EL device according to the present invention may be, for example, a display device of a passive drive type and a see-through type. In this case, the organic EL device can emit light on both sides. However, the organic EL device according to the present invention may be an active drive type light emitting device. Examples of the light emitting device include an optical print head that emits light to expose a photosensitive medium, an illumination device that emits light to illuminate, and a display device that displays a sign or a segment pattern (segment pattern). The shape of the organic EL device according to the present invention is not particularly limited. In this embodiment, the organic EL device 1 having a rectangular shape will be described.

Fig. 1 is a diagram showing an organic EL device 1 according to the present embodiment. Fig. 2 is a sectional view of the organic EL device 1. As shown in fig. 1 and 2, the organic EL device 1 includes an element substrate 2 and a sealing substrate 3 stacked on the element substrate 2, and the sealing substrate 3 is stacked on the element substrate 2 along a stacking direction D1. The organic EL device 1 includes, for example, an element 4 provided on an element substrate 2, a wiring portion 5 extending from between the element substrate 2 and a sealing substrate 3 in a 1 st direction D2, an adhesive 6 for fixing the sealing substrate 3 to the element substrate 2, and a drying agent 7 for covering the element 4.

The organic EL device 1 includes an integrated Circuit 8 and a Flexible Printed Circuit (FPC) 9 provided on the element substrate 2. In the present invention, "covering element" means that the part of the covering element is in contact with at least a portion of the element so as to avoid exposure of the portion of the element. "covering element" includes both the case of covering the entire element and the case of covering a portion of the element.

The 1 st direction D2 indicates a direction in which the wiring portion 5 extends from the element substrate 2, and intersects (for example, orthogonally intersects) the stacking direction D1. In the following description, a direction intersecting (orthogonal to, as an example) both the stacking direction D1 and the 1 st direction D2 will be described as the 2 nd direction D3. However, these directions are set for convenience of explanation, and are not intended to limit the shape, arrangement direction, and the like of each component.

The element substrate 2 is provided with an element 4 and a wiring portion 5. The element substrate 2 is made of glass, for example. Examples of the glass used for the element substrate 2 include alkali-free glass and soda-lime glass. However, the element substrate 2 may be a film-shaped substrate made of a flexible material (for example, a plastic material). Examples of the material of the film-like substrate include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and polyimide.

The element substrate 2 may be a glass substrate, a thin plate glass, or a resin film, and the material of the element substrate 2 is not particularly limited. The element substrate 2 may have optical transparency. For example, the element substrate 2 has a rectangular shape when viewed from the stacking direction D1. The element substrate 2 has, for example, a pair of long sides 2b extending in the 1 st direction D2 and a pair of short sides 2c extending in the 2 nd direction D3. The thickness T6 of the element substrate 2 is, for example, 10 μm or more and 50 μm or less. However, the value of the thickness T6 is not limited to the above example.

The sealing substrate 3 is disposed to face the element substrate 2. The shape of the sealing substrate 3 when viewed from the stacking direction D1 is rectangular. The sealing substrate 3 has a pair of long sides 3g extending in the 1 st direction D2 and a short side 3h extending in the 2 nd direction D3, for example, as in the element substrate 2. For example, the length of the long side 3g of the sealing substrate 3 is shorter than the length of the long side 2b of the element substrate 2. Therefore, in a state where the sealing substrate 3 is fixed on the element substrate 2, a part of the element substrate 2 is exposed from the sealing substrate 3. For example, one side of the element substrate 2 in the 1 st direction D2 is exposed, and the integrated circuit 8, the wiring section 5, and the FPC9 are provided on the exposed portion of the element substrate 2.

The sealing substrate 3 is made of, for example, metal. As an example, the sealing substrate 3 is made of SUS (stainless steel). In this case, SUS may be used as the flexible material of the sealing substrate 3. When the sealing substrate 3 is formed of a thin-film SUS substrate, the flexibility of the sealing substrate 3 can be improved. When the element substrate 2 and the sealing substrate 3 are both made of a flexible material, the organic EL device 1 can be made flexible. However, the material of the sealing substrate 3 may also be a metal material different from SUS. The material of the sealing substrate 3 may be invar (an alloy of nickel and iron), aluminum, nickel, or iron, for example.

The sealing substrate 3 may also be made of a material other than metal. For example, the sealing substrate 3 may be made of glass or made of plastic. The material of the sealing substrate 3 may be the same as that of the element substrate 2, or may be different from that of the element substrate 2. The sealing substrate 3 may have light transmittance. The sealing substrate 3 has a concave portion 3c on a main surface 3b facing the element substrate 2 and recessed in a direction away from the element substrate 2.

The recess 3c is formed in a region including the center of the sealing substrate 3 when viewed in the stacking direction D1. The shape of the recess 3c when viewed from the stacking direction D1 is, for example, rectangular. The recess 3c has a long side 3D extending in the 1 st direction D2 and a short side 3f extending in the 2 nd direction D3. When the sealing substrate 3 is made of metal, the concave portion 3c of the sealing substrate 3 is formed by, for example, drawing. In this case, the cost required for manufacturing the sealing substrate 3 can be reduced. When the sealing substrate 3 is made of glass, the recess 3c is formed by, for example, etching or spot facing.

The thickness (e.g., the length in the stacking direction D1) T1 of the portion of the sealing substrate 3 where the recess 3c is formed is, for example, 10 μm or more and 100 μm or less. The lower limit of the thickness T1 may be 15 μm or 20 μm. The upper limit of the thickness T1 may also be 50 μm, 35 μm or 30 μm. For example, the thickness T1 is 15 μm or more and 35 μm or less. In this case, the strength of the sealing substrate 3 can be maintained more reliably, and the flow of water through the sealing substrate 3 to the inside of the sealing substrate 3 can be prevented.

The depth T2 of the concave portion 3c is, for example, 10 μm or more and 200 μm or less. When the sealing substrate 3 is drawn, the depth T2 corresponds to the drawing depth of the sealing substrate 3. The upper limit of the depth T2 may also be 100 μm. The lower limit of the depth T2 may be 15 μm or 20 μm. However, the values of the thickness T1 and the depth T2 are not limited to the above examples, and may be changed as appropriate.

The element 4 is, for example, an organic EL element portion which emits light by supplying a current. The element 4 is provided on the main surface 2d of the element substrate 2 facing the sealing substrate 3. The element 4 is provided in a region a surrounded by the element substrate 2, the sealing substrate 3, and the adhesive 6. The element 4 is provided with a plurality of organic EL elements 4b and a cathode separation layer (not shown) arranged in a matrix, for example.

Each organic EL element 4b is, for example, a light-emitting element having an anode, a cathode, and an organic light-emitting layer sandwiched between the anode and the cathode. For example, the anode of the organic EL element 4b is formed on the main surface 2d of the element substrate 2. An organic light-emitting layer and a cathode of the organic EL element 4b are formed on the anode in this order. Examples of the material of the anode of the organic EL element 4b include a material having light transmittance such as ITO (indium tin oxide) or IZO (indium zinc oxide).

The organic light-emitting layer of the organic EL element 4b may include an electron injection layer, an electron transport layer, a hole transport layer, and a hole injection layer in addition to the light-emitting layer including the light-emitting material. The light-emitting material of the organic light-emitting layer may be a low-molecular organic compound or a high-molecular organic compound. As the light-emitting material, a fluorescent material or a phosphorescent material may be used. As a material (conductive material) of the conductive layer constituting the cathode of the organic EL element 4b, for example, a material having light transmittance such as aluminum, silver, an alkaline earth metal (magnesium, calcium, or the like), or IZO (indium zinc oxide) can be used. When light is emitted toward the sealing substrate 3, the cathode may be formed to have a light-transmitting thickness.

The wiring section 5 may include a portion provided with a plurality of leads, for example. The wiring section 5 includes a wiring for connecting the element 4 and the integrated circuit 8 between the element 4 and the integrated circuit 8. The wiring section 5 may include a wiring connecting the integrated circuit 8 and the FPC9 between the integrated circuit 8 and the FPC 9. The wiring portion 5 may be formed simultaneously when forming the anode or the cathode of the organic EL element 4b of the element 4. The lead included in the wiring portion 5 is formed of, for example, a single metal layer or a laminated metal layer. A barrier film such as a silicon oxide film or a silicon nitride film may be provided on the surface of the lead.

Fig. 3 is a schematic iii-iii line cross-sectional view of the element substrate 2, the sealing substrate 3, the element 4, the adhesive 6, and the desiccant 7, as viewed from the stacking direction D1. As shown in fig. 2 and 3, the adhesive 6 is a sealing layer that seals the region a between the element substrate 2 and the sealing substrate 3, for example. The adhesive 6 functions as a sidewall for defining the region a. The adhesive 6 is provided between the main surface 2d of the element substrate 2 and the main surface 3b of the sealing substrate 3 in a frame shape.

For example, the adhesive 6 may cover a part of the lead of the wiring portion 5. For example, the adhesive 6 has a rectangular frame shape extending along the edge region 2f of the main surface 2D when viewed in the stacking direction D1. The edge region 2f is a region including the long side 2b and the short side 2c of the element substrate 2, and the width W of the edge region 2f is, for example, 1mm to 2 mm. However, the value of the width W is not limited to the above example, and may be appropriately changed. An exemplary adhesive 6 includes an ultraviolet curable resin. For example, the adhesive 6 may be a spacer including silica particles.

The desiccant 7 covers the elements 4 arranged on the main surface 2d of the element substrate 2. The desiccant 7 covers the element 4 from the stacking direction D1, the 1 st direction D2, and the 2 nd direction D3. For example, the element 4 has no exposed portion on the element substrate 2. The drying agent 7 is in direct contact with the element 4 and covers, for example, the entire element 4. A space 10 is provided on the side of the drying agent 7 opposite to the element 4. The space 10 is present between the sealing substrate 3 and the drying agent 7.

The drying agent 7 includes, for example, a curable resin. The drying agent 7 may be in the form of liquid or gel. The drying agent 7 is, for example, a coating type drying agent coated on the element 4. The desiccant 7 may comprise a resin that is less chemically damaging to the element 4. The drying agent 7 may contain a resin which is less stressed after curing. In this case, the influence on the element 4 caused by the application of the drying agent 7 can be reduced.

The drying agent 7 includes, for example, a plurality of curable resins. In this case, the viscosity of the drying agent 7 can be easily adjusted by including a plurality of curable resins in the base material of the drying agent 7. As an example, the drying agent 7 may include a powder drying agent. The particle diameter of the powder of the drying agent 7 is, for example, 0.1 μm or more and 2.0 μm or less. However, the particle diameter of the powder of the drying agent 7 is not limited to the above value.

Examples of the powder desiccant constituting the desiccant 7 include a desiccant containing an inorganic compound. Examples of the inorganic compound contained in the drying agent 7 include oxides of alkaline earth metals. The oxide of the alkaline earth metal includes, for example, at least one of strontium oxide (SrO), calcium oxide (CaO), magnesium oxide (MgO), and barium oxide (BaO).

The drying agent 7 may contain either SrO or CaO, or both SrO and CaO. When SrO is compared with CaO, SrO has an advantage that the water capture rate is faster than that of CaO. On the other hand, CaO has advantages of large capacity of trapped moisture M and long life. Therefore, when the desiccant 7 contains both SrO and CaO, the water capture rate can be increased, and the life of the desiccant 7 can be extended by securing the capacity of the captured moisture M.

When the desiccant 7 contains both SrO and CaO, the mass ratio of SrO to CaO is, for example, 7: 3. In this case, the following effects can be obtained well: high speed of water capture is ensured by SrO, water capture capacity is ensured by CaO, and service life is ensured. However, the mass ratio of SrO to CaO may be, for example, 8:2 or 5:5, and may be appropriately changed.

The concentration of powdered SrO (or CaO) in the drying agent 7 is, for example, 70 wt% or more. However, the concentration may be 65 wt% or more, or 60 wt% or more. In this case, the water capture speed and the water capture capacity of the desiccant 7 can be appropriately increased. Further, the drying agent 7 may contain a liquid drying agent containing a metal alkoxide as a water trapping component, or may contain an organic metal. Examples of the organic metal constituting the drying agent 7 include aluminum, titanium, and magnesium. The drying agent 7 containing an organic metal can increase the water capturing speed and thus can capture water more efficiently. The gel-like or liquid-like drying agent 7 exemplified above is applied to the element 4 so as to cover the element 4 on the element substrate 2, and then cured, thereby being in close contact with the element 4 in this state.

As described above, the space 10 is formed between the desiccant 7 and the sealing substrate 3. The space portion 10 includes, for example, a 1 st space portion 11 located on the lamination direction D1 side of the desiccant 7, a 2 nd space portion 12 located between the desiccant 7 and the adhesive 6, and a 3 rd space portion 13 facing the corner portion 3j of the recess 3c of the sealing substrate 3. The 1 st space portion 11 is formed between the main surface 3b of the sealing substrate 3 and the surface 7b of the desiccant 7 facing the stacking direction D1. The 2 nd space 12 is formed between the inner surface 6b of the adhesive 6 facing the element 4 and the side surface 7c of the desiccant 7. The 3 rd space portion 13 is a region provided obliquely above the drying agent 7, and is formed between the drying agent 7 and the corner portion 3j of the recess 3 c.

The 1 st space 11 is formed in a region overlapping with the desiccant 7 when viewed in the stacking direction D1. The 1 st space portion 11 is formed in a rectangular shape, for example, when viewed from the stacking direction D1. The 1 st space portion 11 has a thickness in the stacking direction D1. However, since the desiccant 7 contains a powder component, irregularities are formed on the surface 7b on the side of the lamination direction D1 of the desiccant 7, and a part of the surface 7b may come into contact with the main surface 3b of the sealing substrate 3.

The thickness T3 of the 1 st space portion 11 in the stacking direction D1 is determined by the depth T2 of the recess 3c of the sealing substrate 3, the thickness T4 in the stacking direction D1 of the adhesive 6, and the thickness T5 in the stacking direction D1 of the desiccant 7. As described above, the depth T2 of the concave portion 3c is, for example, 10 μm or more and 200 μm or less. For example, the thickness T3 of the 1 st space portion 11 is 5 μm or more. The upper limit of the thickness T3 is, for example, 250 μm or 100 μm.

The thickness T3 may be an average value of the distance from the irregularities formed on the surface 7b of the desiccant 7 to the main surface 3b of the sealing substrate 3. The thickness T3 may be 8 μm or more or 10 μm or more. For example, when the thickness T4 of the adhesive 6 is 20 μm and the depth T2 is 10 μm to 200 μm, the thickness T5 of the desiccant 7 is 25 μm to 215 μm. However, the values of the depth T2, the thickness T3, the thickness T4, and the thickness T5 may be changed as appropriate.

The 2 nd space portion 12 and the 3 rd space portion 13 are provided outside the 1 st space portion 11 as viewed in the stacking direction D1. The 2 nd space portion 12 and the 3 rd space portion 13 are frame-shaped to surround the 1 st space portion 11 when viewed from the stacking direction D1. The 3 rd space portion 13 is provided on the opposite side (for example, the upper side in fig. 2) of the 2 nd space portion 12 from the element substrate 2, and is located obliquely above the adhesive 6. As described above, by forming the 1 st space 11, the 2 nd space 12, and the 3 rd space 13, the path L of the moisture M is formed between the drying agent 7 and the sealing substrate 3 and between the drying agent 7 and the adhesive 6.

Here, a case where moisture M enters space portion 10 from the outside of sealing substrate 3 and adhesive 6 is considered. In the present embodiment, moisture M passes through adhesive 6 and enters space 10, and moisture M entering from adhesive 6 enters 2 nd space 12 and reaches 1 st space 11 via 3 rd space 13. For example, in the 1 st space 11, the moisture M propagates and diffuses in both the 1 st direction D2 and the 2 nd direction D3, and is captured by the desiccant 7 during propagation and diffusion. A dark colored portion 7d of the desiccant 7 in fig. 2 schematically shows a portion of the desiccant 7 after trapping water. Since the moisture M contacts the desiccant 7 not only from the 1 st space 11 but also from the 2 nd space 12 and the 3 rd space 13, the desiccant 7 can capture the moisture M that has entered over a large area.

Next, the operation and effects of the organic EL device 1 according to the present embodiment will be described in detail. In the organic EL device 1, the element 4 provided on the element substrate 2 is covered with the desiccant 7. Therefore, the moisture M that has entered the sealing substrate 3 adheres to the desiccant 7, and the element 4 can be protected from the moisture M. In the present embodiment, since the desiccant 7 is directly formed on the element 4, the moisture M entering the inside of the sealing substrate 3 does not directly contact the element 4.

Therefore, since the element 4 can be protected from foreign matter containing the moisture M by the desiccant 7, it is possible to more effectively suppress a light emission failure (light emission shrinkage) from the edge portion of the element 4, which occurs as the moisture M adheres to the element 4. Therefore, the life of the organic EL device 1 including the element 4 can be prolonged. A space portion 10 is formed inside the sealing substrate 3, and the space portion 10 is provided between the drying agent 7 and the sealing substrate 3. Therefore, the desiccant 7 is exposed to the space portion 10 inside the sealing substrate 3, and thus the area of the desiccant 7 to which the moisture M has adhered can be secured to be large, and therefore the desiccant 7 can be sufficiently effectively used.

Since a sufficient water-trapping effect can be obtained with a small amount of the desiccant 7, the space for installing the desiccant 7 can be reduced. The size of the 2 nd space 12 and the 3 rd space 13 can be reduced. By forming the space portion 10 between the sealing substrate 3 and the drying agent 7, it is possible to make it difficult for the external force applied to the sealing substrate 3 to be transmitted to the drying agent 7 and the element 4, and therefore it is possible to improve resistance against the external force. Therefore, it can be made less susceptible to external force.

The sealing substrate 3 may be made of metal. In this case, compared with the case where the sealing substrate is made of resin or the like, it is possible to make it difficult for the moisture M to flow to the inside of the sealing substrate 3 through the sealing substrate 3, and it is possible to improve the strength as the sealing substrate 3. The sealing substrate 3 made of metal has flexibility, and therefore resistance against bending can be improved. In the case where the sealing substrate 3 is made of metal, the concave portion 3c of the sealing substrate 3 can be formed by drawing, and therefore, the cost required for working or the like can be reduced.

The thickness T1 of the sealing substrate 3 may be 10 μm or more and 100 μm or less. In this case, since the strength of the sealing substrate 3 can be ensured by setting the thickness T1 of the sealing substrate 3 to 10 μm or more, it is possible to avoid forming holes in the sealing substrate 3 when processing or the like is performed. By setting the thickness T1 of the sealing substrate 3 to 100 μm or less, the sealing substrate 3 can be prevented from becoming too hard, and thus the processing of the sealing substrate 3 can be easily performed.

Thickness T3 of space portion 10 may be 5 μm or more. In this case, by setting thickness T3 of space portion 10 to 5 μ M or more, moisture M entering inside sealing substrate 3 can be sufficiently diffused in space portion 10. As a result, the desiccant 7 can be used to capture water more reliably, and the desiccant 7 can be used more effectively. By setting thickness T3 of space portion 10 to 5 μm or more, external force can be more hardly transmitted to desiccant 7 and element 4, which contributes to further improvement in strength.

The drying agent 7 may contain an alkaline earth metal and a curable resin. In this case, the drying agent 7 can be cured by including the drying agent 7 with a curable resin. By including an alkaline earth metal in the desiccant 7, the water-trapping property as the desiccant 7 against the moisture M entering the inside of the sealing substrate 3 can be improved. Moreover, the life of the desiccant 7 can be extended.

The embodiments of the organic EL device according to the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit and scope of the invention as set forth in the claims. That is, the shape, size, number, material, and arrangement of each part of the organic EL device may be appropriately changed within the scope not changing the above-described gist.

For example, in the above embodiment, the following example is explained: the concave portion 3c is formed by drawing in the case where the sealing substrate 3 is made of metal, and the concave portion 3c is formed by etching in the case where the sealing substrate 3 is made of glass. However, the method of forming the concave portion of the sealing substrate may be a method other than drawing or etching.

In the above embodiment, the space 10 including the 1 st space 11, the 2 nd space 12, and the 3 rd space 13 is explained. In this case, since the surfaces (for example, five surfaces including the one surface 7b and the four side surfaces 7 c) of the desiccant 7 other than the surface in contact with the element substrate 2 are exposed to the space portion 10, the water trapping area of the desiccant 7 can be ensured to be larger, and a higher water trapping effect can be obtained. However, the configuration of the space portion is not limited to the 1 st space portion 11, the 2 nd space portion 12, and the 3 rd space portion 13. The space portion may be, for example, a space portion not having at least one of the 2 nd space portion 12 and the 3 rd space portion 13. The shape of the space portion and the like may be appropriately changed.