JP2006233285A - Vapor deposition mask and method for producing organic el element using the vapor deposition mask - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vapor deposition mask with which the reduction in the precision of a vapor deposition position caused by the influence of radiant heat from a vapor deposition source generated during vapor deposition is suppressed, and to provide a method for producing an organic EL (electroluminescence) element using the same. <P>SOLUTION: In the vapor deposition mask having an opening arraying group, the light reflectivity in the wavelength of 2μm at least on the side of a vapor deposition source is ≥90%. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing an organic EL element that can be used in fields such as a display element, a flat panel display, a backlight, and an interior.

  An organic EL element emits light by recombining holes injected from an anode and electrons injected from a cathode in an organic light emitting layer sandwiched between both electrodes. A typical structure is a transparent first electrode (anode), a hole transport layer, an organic light emitting layer, and a second electrode (cathode) laminated on a glass substrate. It is taken out through the electrode and the glass substrate. Such an organic EL element is thin, can emit high-intensity light emission under low-voltage driving, and can emit multicolor light by selecting an organic light-emitting material, and has been actively studied for application to light-emitting devices and displays.

  Organic thin films such as a hole transport layer, a light emitting layer, and an electron transport layer are often formed by a vacuum deposition method. As a pattern forming method of these organic thin films, an evaporation mask having an opening corresponding to the pattern formation region is disposed between the substrate and the evaporation source, and in this state, an organic material is evaporated from the evaporation source, A method of forming an organic thin film at a specific site on the substrate is used. When the vapor deposition source is heated, infrared rays are emitted from the vapor deposition source, and the temperature of the vapor deposition mask rises due to this radiant heat. The rise in the temperature of the vapor deposition mask causes thermal expansion of the mask and causes a positional deviation from the substrate, so that the positional accuracy of the organic thin film pattern formation is deteriorated. Further, when the thermal expansion of the vapor deposition mask is further large, there is a problem that the vapor deposition mask is bent, so that a gap is formed between the vapor deposition mask and the substrate, and the organic thin film pattern cannot be formed (called patterning blur).

As means for solving the above-mentioned conventional problems, a method for producing a vapor deposition mask with ceramics having a small thermal expansion coefficient (see Patent Document 1) and a method for aligning the thermal expansion coefficients of the vapor deposition mask and the substrate (Patent Document) 2), a method of providing an infrared blocking body covering other than the outlet of the vapor deposition source (see Patent Document 3), a method of flowing cooling water through the vapor deposition mask frame (see Patent Document 4), and the like.
JP 2003-170352 A (Claim 1) Japanese Patent Laying-Open No. 2003-77660 (Claim 2) JP 2004-214185 A (Claim 1) JP 2002-8859 A (Claim 1)

  However, ceramic vapor deposition masks are difficult to handle because they are fragile, and the method of aligning the thermal expansion coefficient between the vapor deposition mask and the substrate does not suppress the generation of a gap between the vapor deposition mask and the substrate when the mask is bent due to temperature rise. The method of covering the vapor deposition source with the body cannot completely prevent the heat rays from the injection port, and the method of flowing cooling water through the vapor deposition mask frame has a problem that uniform cooling is difficult.

  An object of the present invention is to solve such problems and to provide a vapor deposition mask that suppresses a decrease in pattern position accuracy due to the influence of radiant heat from a vapor deposition source generated during vapor deposition, and a method for manufacturing an organic EL element using the same. And

  In order to solve this problem, the present invention has the following configuration. That is, it is a vapor deposition mask having an aperture arrangement group, and the vapor reflectivity is such that the light reflectance at a wavelength of 2 μm on at least the side surface of the vapor deposition source is 90% or more.

  According to the present invention, since the radiant heat generated from the vapor deposition source can be suppressed, it is possible to prevent deterioration in positional accuracy due to thermal expansion of the vapor deposition mask during vapor deposition (organic thin film pattern formation).

The present invention is described in detail below. The present invention is applicable to a manufacturing method using a vapor deposition mask in a manufacturing process regardless of the type of organic EL elements such as a single light emitting element, a segment type, a simple matrix type, and an active matrix type, and the number of luminescent colors such as color and monochrome. Is possible.
The present invention is a vapor deposition mask capable of suppressing the influence of radiant heat from a vapor deposition source. During vapor deposition, infrared rays having a wavelength corresponding to the vapor deposition source temperature are emitted from the vapor deposition source. For example, in the vapor deposition step of the organic EL element, the temperature of the vapor deposition source is 500 K (227 ° C.) or higher, and at this time, infrared rays having a wavelength longer than 2 μm greatly affect the thermal expansion of the mask. For this reason, the vapor deposition mask of the present invention has a light reflectance of at least 90% at a wavelength of 2 μm at least on the side surface of the vapor deposition source. The larger the reflectance, the more the influence of radiant heat from the vapor deposition source can be suppressed, but the effect can be sufficiently exhibited if it is 90% or more. Hereinafter, the vapor deposition mask of the present invention having a light reflectance of 90% or more at a wavelength of 2 μm is referred to as a light reflective vapor deposition mask, and the light reflectance at a wavelength of 2 μm is referred to as an infrared reflectance.
The light reflective vapor deposition mask in the present invention only needs to have a reflectance of 90% or more at a wavelength of 2 μm on the side surface of the vapor deposition source, and further, an infrared reflector having the above reflectance is provided on the side surface of the vapor deposition source. It is preferable. At this time, even if it forms with the same raw material of a vapor deposition mask main body and an infrared reflector, the material which comprises each may differ from each other.
The material having a high infrared reflectance cannot be particularly limited, but silver, copper, aluminum, gold and the like can be mentioned as particularly suitable materials, and these can be used alone or as a mixture of a plurality of types of materials ( Alloy). As described above, the main part of the light reflection vapor deposition mask may be manufactured using these materials. Moreover, in this invention, as shown in FIG. 1, it can obtain easily by forming the infrared reflector 1 in the vapor deposition mask 2 produced by the existing methods, such as an etching method and an electroforming method. The material for forming the infrared reflector is not particularly limited as long as it is a material having a high infrared reflectance, but silver, copper, aluminum, gold and the like can be mentioned as particularly suitable materials, and these can be used alone or It can also be used as a mixture (alloy) of a plurality of types of materials.
An evaporation mask manufactured by an existing method mainly uses a nickel alloy, an iron alloy, or the like. Therefore, although the aperture accuracy is excellent, the infrared reflectance is relatively low. This material is easily affected by radiant heat from the vapor deposition source and is likely to thermally expand. However, in the present invention, even when a material having a low infrared reflectance is used, a high radiant heat suppression effect can be imparted to the vapor deposition mask by providing an infrared reflector on at least the vapor deposition source side surface of the vapor deposition mask. In particular, a conventional vapor deposition mask made of a nickel alloy produced by electroforming has a large coefficient of thermal expansion and is greatly affected by radiant heat by infrared rays, and therefore the effect of suppressing radiant heat according to the present invention is great. Thus, by selecting the deposition mask and the material forming the infrared reflector from different materials, it is possible to easily produce a deposition mask having both high aperture accuracy and a radiant heat suppression effect. The reflectance of the infrared reflector can be measured by an existing method such as FT-IR or spectroscopic ellipsometry.
As a method for setting the light reflectance at a wavelength of 2 μm of the vapor deposition mask main body to 90% or more, it can be produced by using a material having a high infrared reflectance such as silver, copper, aluminum or gold as a mask material. Specifically, the above-described high reflectivity material is processed into a film in advance by using a single material or an alloying method such as arc melting that has been incorporated into another material, and this is processed into an etching method or mechanical polishing. It can be produced by processing into a deposition mask shape by a sandblasting method, a sintering method, a laser processing method or the like. When producing a vapor deposition mask as an alloy with another material, it is necessary to adjust the composition so that the infrared reflectance of the alloy is 90% or more.

  When the materials constituting the vapor deposition mask and the infrared reflector are different from each other, methods for forming the infrared reflector on the vapor deposition mask include vacuum heating methods such as resistance heating wire vapor deposition and sputtering, plating methods, printing methods, etc. Any method can be used. Forming by a vacuum deposition method is the most preferable method because a particularly high infrared reflectance can be obtained due to surface flatness and the influence of low impurity concentration. If the film thickness of the infrared reflector is at least 5 nm or more, the effect of suppressing radiant heat appears. However, considering the uniformity of the film thickness, it is preferably 10 nm or more. On the other hand, if the film thickness is too large, the problem of “evaporation shadow” occurs.

Hereinafter, the manufacturing method of the organic EL element using the light reflection vapor deposition mask of this invention is demonstrated.
In the method for producing an organic EL element of the present invention, a step of forming a first electrode on a substrate, a step of forming an organic thin film layer including at least a light emitting layer on the first electrode, and a second electrode on the organic thin film layer Are sequentially formed, and the light emitting layer is patterned using a light reflective vapor deposition mask having a light reflectance of 90% or more at least at a wavelength of 2 μm on the side surface of the vapor deposition source.
FIG. 2 shows a method for manufacturing a simple matrix type organic EL element as an example of a method for manufacturing an organic EL element in the present invention. After the first electrode 8 is patterned on the substrate 5 in a striped manner by a known method such as sputtering, a hole transport material 9 is deposited on the entire light emitting region of the substrate by vacuum deposition. Next, as the infrared reflector 1, a light reflective vapor deposition mask 2 in which a material having a high infrared reflectance such as silver, copper, aluminum, gold or the like is formed by vacuum vapor deposition is used. The vapor deposition source 3 is heated in a state in which the first electrode is located at the same position, and the first light emitting material 4 is vapor deposited. At this time, the first light emitting material 4 is evaporated from the vapor deposition source toward the substrate 5, but the infrared rays 6 (illustrated by arrows) are emitted to the light reflection vapor deposition mask 2 simultaneously with the vapor deposition 7. Next, the light reflective vapor deposition mask is moved relative to the first electrode on the substrate by one pitch, and the second and third light emitting materials are deposited in the same manner as the first light emitting material. Finally, an electron transport material is patterned in a stripe pattern on the entire surface of the light emitting region of the substrate and the second electrode is orthogonal to the first electrode, thereby obtaining a simple matrix type organic EL device that emits three colors. .

When the light-emitting material is laminated thickly on the light-reflecting vapor deposition mask, the laminated light-emitting material absorbs infrared rays emitted from the vapor deposition source, and the mask further stores heat. That is, the reflectance of the infrared reflector is reduced. In such a case, after a predetermined number of vapor deposition steps, the light reflective vapor deposition mask is washed, or an infrared reflector is formed again on the light emitting material laminated on the light reflective vapor deposition mask. The reflectance can be restored to the initial state.
As a cleaning method of the light reflection vapor deposition mask, any method such as a wet process in contact with an organic solvent or a dry process such as UV ozone treatment can be used.

  The first electrode and the second electrode used in the organic EL element have a role of supplying a sufficient current for light emission of the element, and it is desirable that at least one of them is transparent for extracting light.

  Preferred transparent electrode materials include tin oxide, zinc oxide, indium oxide, ITO and the like. For the purpose of patterning, it is preferable to use ITO excellent in workability.

  When patterning the first electrode, a photolithography method involving wet etching can be used. The pattern shape of the first electrode is not particularly limited, and an optimal pattern may be selected depending on the application. In the present invention, a plurality of striped electrodes arranged with a certain interval can be cited as a preferable example.

  The organic thin film layer included in the organic EL element of the present invention is composed of a light emitting layer and other functional layers. The light emitting layer is a functional layer that emits light. Other functional layers include an electron transport layer for injecting electrons into the light emitting layer or transporting electrons (hereinafter, a material used for the layer is referred to as an electron transport material), a hole being injected into the light emitting layer, or a positive layer. And a hole transport layer for transporting holes (a material used for the layer is hereinafter referred to as a hole transport material).

  As the hole transporting material, N, N′-diphenyl-N, N′-di (3-methylphenyl) -1,1′-diphenyl-4,4′-diamine (TPD), N, N′— Triphenylamines represented by diphenyl-N, N′-dinaphthyl-1,1′-diphenyl-4,4′-diamine (NPD), N-isopropylcarbazole, biscarbazole derivatives, pyrazoline derivatives, stilbene compounds , Hydrazone compounds, heterocyclic compounds typified by oxadiazole derivatives and phthalocyanine derivatives, and polymer systems are preferably polycarbonates or polystyrene derivatives having the above-mentioned monomers in the side chain, polyvinylcarbazole, polysilane, polyphenylene vinylene, etc. It is not limited.

  In addition to anthracene, pyrene, and 8-hydroxyquinoline aluminum, the material of the light emitting layer includes, for example, bisstyryl anthracene derivatives, tetraphenylbutadiene derivatives, coumarin derivatives, oxadiazole derivatives, distyrylbenzene derivatives, pyrrolopyridine derivatives, In the case of perinone derivatives, cyclopentadiene derivatives, thiadiazolopyridine derivatives, and polymer systems, polyphenylene vinylene derivatives, polyparaphenylene derivatives, polythiophene derivatives, and the like can be used. As the dopant added to the light emitting layer, rubrene, quinacridone derivatives, phenoxazone 660, DCM1, perinone, perylene, coumarin 540, diazaindacene derivatives and the like can be used as they are.

  The electron transport material is required to efficiently transport electrons from the cathode between electrodes to which an electric field is applied, has high electron injection efficiency, and preferably transports injected electrons efficiently. For this purpose, a substance having a high electron affinity, a high electron mobility, excellent stability, and a trapping impurity that is unlikely to occur during manufacture and use is preferable. Specifically, quinolinol derivative metal complexes represented by 8-hydroxyquinoline aluminum, tropolone metal complexes, flavonol metal complexes, perylene derivatives, perinone derivatives, naphthalene derivatives, coumarin derivatives, oxadiazole derivatives, aldazine derivatives, bisstyryl derivatives, pyrazines Examples include derivatives, oligopyridine derivatives such as bipyridine and terpyridine, phenanthroline derivatives, quinoline derivatives, and aromatic phosphorus oxide compounds. These electron transport materials are used alone, but may be used by being laminated or mixed with different electron transport materials.

  The materials used for the hole transport layer, the light emitting layer, and the electron transport layer can form each layer alone. Polyvinyl chloride, polycarbonate, polystyrene, poly (N-vinylcarbazole) are used as the polymer binder. , Polymethyl methacrylate, polybutyl methacrylate, polyester, polysulfone, polyphenylene ether, polybutadiene, hydrocarbon resin, ketone resin, phenoxy resin, polyurethane resin and other solvent-soluble resins, phenol resin, xylene resin, petroleum resin, urea resin, melamine It can also be used by being dispersed in a curable resin such as a resin, an unsaturated polyester resin, an alkyd resin, an epoxy resin, or a silicone resin.

  The cathode serving as the second electrode is not particularly limited as long as it can efficiently inject electrons into the electron transport layer or the light emitting layer included in the device of the present invention. Therefore, it is possible to use low work function metals such as alkali metals, but considering the stability of the electrodes, metals such as platinum, gold, silver, copper, iron, tin, aluminum, magnesium, indium, or these metals A preferable example is an alloy of a low work function metal and the like. In addition, a stable electrode can be obtained while maintaining high electrode injection efficiency by previously doping a small amount of a low work function metal into the organic thin film layer and then forming a film using a relatively stable metal as a cathode. These electrodes are preferably produced by a dry process such as resistance heating vapor deposition, electron beam vapor deposition, sputtering, or ion plating.

  In addition, although the application example to an organic EL element was demonstrated above, this invention is not limited only to an organic EL element, Various semiconductor device manufacturing processes including (organic, inorganic) TFT, a solar cell, LCD, It can be used in various fields that require vapor deposition, such as various display manufacturing processes such as PDP and lighting manufacturing processes. For organic EL elements, a vapor deposition mask is used in the manufacturing process regardless of the type of organic EL elements such as single light-emitting elements, segment types, simple matrix types, and active matrix types, and the number of luminescent colors such as color and monochrome. It is possible to apply to the manufacturing method to be used.

  EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated, this invention is not limited by these examples.

Example 1
Production of Light Reflective Deposition Mask for Light-Emitting Layer A resist pattern was formed by photolithography on a stainless steel electroformed mold. Next, a nickel alloy was deposited in the region of the mask portion having no resist pattern on the electroforming mold by electroforming to form a thickness of 20 to 28 μm. After removing the resist pattern, the laminate was peeled off from the electroforming mother mold and adhered to a stainless steel frame having a width of 4 mm while applying a tension to prepare a vapor deposition mask. The outer shape of the produced deposition mask is 120 × 84 mm. In FIG. 3, the opening 11 and the reinforcing wire 12 are shown. The openings 11 are rectangular having a width of 100 μm and a length of 280 μm, and 272 are formed at a pitch of 300 μm in the width direction and 200 are formed at a pitch of 300 μm in the length direction. The width of the reinforcing wire 12 is 20 μm.

Next, the vapor deposition mask was transferred into a vacuum chamber (manufactured by SYNCHRON Co., Ltd.), and silver (purity = 99.99%) was formed as an infrared reflector on the entire surface of the vapor deposition mask under a vacuum degree of 2 × 10 ⁻⁴ Pa. As described above, Kishida Chemical Co., Ltd.) was formed by vacuum deposition by a resistance wire heating method so that the film deposition rate was 0.5 nm / s and the film thickness was 50 nm. The light reflectance at a wavelength of 2 μm of the light reflective vapor deposition mask on which the infrared reflector is formed is determined by the FT-IR method (FTIR-8000, manufactured by Shimadzu Corporation) at a portion where the opening of the mask end is not present. The result of measurement under a dry nitrogen flow was 98%.

Preparation of Organic EL Element The first electrode was obtained by applying a photoresist on an ITO glass substrate having a size of 120 × 100 mm, exposing and developing, and patterning the ITO film into a stripe shape having a length of 90 mm and a width of 80 μm. 816 stripe-shaped first electrodes are arranged at a pitch of 100 μm.

  Next, a positive photoresist (“OFPR-800”, manufactured by Tokyo Ohka Kogyo Co., Ltd.) was applied by spin coating to a thickness of 3 μm on the substrate on which the first electrode was formed. The coating film was subjected to pattern exposure through a photomask, developed to pattern a photoresist, and cured at 200 ° C. after development. In this insulating layer, 816 openings having a width of 70 μm and a length of 250 μm are arranged at a pitch of 100 μm in the width direction and 200 pieces at a pitch of 300 μm in the length direction. The insulating layer covers the edge portion of the ITO, and the ITO is exposed from the opening.

The thin film layer including the light emitting layer was formed by a vacuum evaporation method using a resistance wire heating method. In addition, the vacuum degree at the time of vapor deposition was 2 * 10 <^-4> Pa, and the board | substrate was rotated with respect to the vapor deposition source during vapor deposition. First, 10 nm of copper phthalocyanine and bis (N-ethylcarbazole) were vapor-deposited on the entire surface of the pixel area to form a hole transport layer.

  The light reflecting vapor deposition mask for the light emitting layer on which the infrared reflector was formed was placed in front of the substrate to bring them into close contact, and a ferrite plate magnet (manufactured by Hitachi Metals, Ltd., YBM-1B) was placed behind the substrate. At this time, the stripe-shaped first electrode was positioned at the center of the opening of the vapor deposition mask, the reinforcing wire was positioned on the insulating layer, and the reinforcing wire and the insulating layer were in contact with each other. In this state, aluminum doped with 0.3% by weight of 1,3,5,7,8-pentamethyl-4,4-difluoro-4-bora-3a, 4a-diaza-s-indacene (Exxington PM546) A quinolinol complex (hereinafter referred to as Alq3) was deposited by 20 nm, and the green light emitting layer was patterned.

  Next, the light reflecting vapor deposition mask for the light emitting layer is aligned with the first electrode pattern shifted by one pitch, and 1% by weight of 4- (dicyanomethylene) -2-methyl-6- (julolidylstyryl) Alq3 doped with pyran (DCJT) was deposited to a thickness of 15 nm, and the red light emitting layer was patterned.

  Further, the light reflecting vapor deposition mask for the light emitting layer is aligned with the first electrode pattern shifted by one pitch, and 4,4′-bis (2,2′-diphenylvinyl) diphenyl is deposited by 20 nm to obtain a blue light emitting layer. Was patterned. During the light emitting layer deposition, the temperature of the deposition source was in the range of 520 to 700 K, and the distance between the substrate and the deposition source was 20 cm.

  Next, bathocuproine (phenanthroline derivative) was deposited on the entire surface of the 45 nm substrate to form an electron transport layer. Thereafter, the thin film layer was exposed to lithium vapor and doped (0.5 nm in terms of film thickness).

  For the second electrode patterning, a shadow mask having a structure in which a gap exists between one surface of the mask portion and the reinforcing line was used. The shadow mask has an outer shape of 120 × 84 mm, the thickness of the mask portion is 100 μm, and 200 striped openings having a length of 100 mm and a width of 260 μm are arranged at a pitch of 300 μm. On the mask portion, a mesh-like reinforcing wire having a regular hexagonal structure with a width of 38 μm, a thickness of 35 μm, and a distance between two opposing sides of 200 μm is formed. The height of the gap is equal to the thickness of the mask part and is 100 μm. The shadow mask is fixed to a stainless steel frame having the same outer shape and a width of 4 mm.

The second electrode was formed by a vacuum vapor deposition method using a resistance wire heating method. In addition, the vacuum degree at the time of vapor deposition was 3 * 10 <^-4> Pa or less, and the board | substrate was rotated with respect to two vapor deposition sources during vapor deposition. Similar to the patterning of the light emitting layer, a shadow mask for the second electrode was disposed in front of the substrate to bring them into close contact with each other, and a plate magnet was disposed in the rear of the substrate. At this time, both are arranged so that the insulating layer coincides with the mask portion. In this state, aluminum was deposited to a thickness of 240 nm to pattern the second electrode.

  The substrate on which the patterning of the second electrode had been completed was taken out of the vapor deposition machine and transferred to an argon atmosphere with a dew point of −80 ° C. or lower. In this low humidity atmosphere, the substrate and the sealing plate were bonded together using a curable epoxy resin and sealed.

  In this manner, the patterned green light emitting layer, red light emitting layer, and blue light emitting layer are formed on the stripe-shaped first electrodes made of ITO films having a pitch of 100 μm and 816 pieces so as to be orthogonal to the first electrodes. A simple matrix type color organic EL element in which 200 stripe-shaped second electrodes with a pitch of 300 μm were arranged was produced.

  The light emitting layer patterning accuracy of the obtained organic EL element was evaluated by measuring the positional deviation between the first electrode and each color light emitting layer by observation with a fluorescent microscope. The measurement points were measured at the maximum value of the amount of misregistration of each color of red, blue, and green at a total of five points in the four corners and the central part of the obtained organic EL element light emitting region. As a result, the patterning shift amount of the light emitting layer was 6 μm at maximum, and extremely good accuracy was obtained. Further, the organic EL element was able to emit light uniformly without color mixing over the entire light emitting region.

Example 2
As an infrared reflector, copper (purity = 99.99% or more, manufactured by Mitsubishi Materials Corporation) was deposited by DC sputtering (manufactured by ULVAC, Inc.) in an argon atmosphere with a vacuum degree = 0.2 Pa, and a lamination rate = 1 nm. A light reflective vapor deposition mask for light emitting layer was produced in the same manner as in Example 1 except that the film thickness was 50 nm at / s. The reflectance of the obtained light reflective vapor deposition mask at a wavelength of 2 μm was 96% as a result of measurement under a dry nitrogen flow by the FT-IR method (FTIR-8000, manufactured by Shimadzu Corporation). Next, an organic EL element was produced and evaluated in the same manner as in Example 1 using the obtained light reflective vapor deposition mask. As a result, the patterning shift amount of the light emitting layer was 10 μm at the maximum, and good patterning accuracy was obtained. Further, the organic EL element was able to emit light uniformly without color mixing over the entire light emitting region.

Example 3
A light reflective vapor deposition mask for light emitting layer was produced in the same manner as in Example 1 except that silver was changed to aluminum (purity = 99% or more, manufactured by Mitsuwa Chemical Co., Ltd.) as the infrared reflector. The reflectance at a wavelength of 2 μm of the obtained light reflection vapor deposition mask was 93% as a result of measurement under a dry nitrogen flow by the FT-IR method (FTIR-8000, manufactured by Shimadzu Corporation). Next, an organic EL element was produced and evaluated in the same manner as in Example 1 using the obtained light reflective vapor deposition mask. As a result, the maximum amount of patterning misalignment of the light emitting layer was 12 μm, and good patterning accuracy was obtained. Further, the organic EL element was able to emit light uniformly without color mixing over the entire light emitting region.

Comparative Example 1
A light emitting layer deposition mask was prepared in the same manner as in Example 1 except that the infrared reflector was not formed. The reflectance at a wavelength of 2 μm of the obtained vapor deposition mask was 84% because the surface was a nickel alloy as a result of measurement under a dry nitrogen flow by the FT-IR method (FTIR-8000, manufactured by Shimadzu Corporation). there were. Next, an organic EL device was produced and evaluated in the same manner as in Example 1 using the obtained vapor deposition mask. As a result, the patterning shift amount of the light emitting layer was 20 μm at maximum, and a color mixture of the light emitting layers adjacent to each other was observed. In addition, patterning blur was observed in a part of the light emitting region, suggesting that the mask was bent due to thermal expansion during vapor deposition.

Schematic which showed the vapor deposition mask and vapor deposition source in this invention. Schematic which showed the vapor deposition means in this invention. Schematic of a vapor deposition mask.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Infrared reflector 2 Evaporation mask 3 Evaporation source 4 Luminescent material 5 Substrate 6 Infrared 7 Deposited material 8 First electrode 9 Hole transport material 10 Frame 11 Opening 12 Reinforcement line

Claims (5)

A vapor deposition mask having an aperture array group, wherein the light reflectance at a wavelength of 2 μm on at least a side surface of the vapor deposition source of the vapor deposition mask is 90% or more. The vapor deposition mask according to claim 1, wherein an infrared reflector is provided on at least a side surface of the vapor deposition source of the vapor deposition mask. 2. The vapor deposition mask according to claim 1, wherein an infrared reflector is provided on at least a side surface of the vapor deposition source of the vapor deposition mask, and a material constituting the infrared reflector and a material constituting the mask base are different from each other. The vapor deposition mask according to claim 2 or 3, wherein the infrared reflector includes a metal selected from at least one of silver, copper, aluminum, and gold. The process of forming a 1st electrode on a board | substrate, the process of forming the organic thin film layer which contains an at least light emitting layer on a 1st electrode, and manufacture of the organic EL element formed in order by forming a 2nd electrode on an organic thin film layer A method for producing an organic EL device, wherein the light emitting layer is patterned using a vapor deposition mask having a light reflectance of 90% or more at a wavelength of 2 μm on at least a side surface of the vapor deposition source.

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