JP6036249B2 - Method for manufacturing organic electroluminescence device - Google Patents

Description

  The present invention relates to a method for manufacturing an organic electroluminescence element, and particularly relates to a method for manufacturing an organic electroluminescence element capable of forming a functional layer with high accuracy.

  A technique is known in which a long strip-shaped base material having flexibility is conveyed by a roll-to-roll method, and a predetermined treatment (formation of a functional layer by patterning, etc.) is performed on the strip-shaped base material. This technique can be applied to, for example, the manufacture of an organic electroluminescence (EL) element attracting attention as a light emitting element.

  When this technique is applied to the manufacture of an organic EL element, for example, first, a wound belt-shaped substrate is fed out from a roll. And tension | tensile_strength is provided to the conveyance direction of a strip | belt-shaped base material, a base material is normally conveyed to a predetermined position, contacting the conveyance roll provided with two or more, and an organic electroluminescent structure (functional layer) is carried out on the extended | stretched base material. It is formed by patterning or the like. Next, the base material on which the organic EL structure is formed is sealed with, for example, a laminate, wound up on another roll, and cut into a predetermined size as necessary to obtain an organic EL element. . Such roll-to-roll manufacturing has the advantage that continuous production is possible and production efficiency can be improved.

  However, in this case, depending on the process performed on the base material (for example, formation of a functional layer), it may be preferable to prevent the processed region from coming into contact with the transport roll. This is because when the processing area comes into contact with the transport roll, dust, foreign matter, or the like may adhere to the processing area or be damaged. In addition, for example, when the functional layer is formed on the processing region and then comes into contact with the transport roll, the functional layer may be scraped or scratched by the contact, for example. And the function which a functional layer has may be impaired by these.

  Therefore, there is a method in which air is ejected through a vent provided in the surface of the transport roll so that the base material is not in contact with the transport roll as much as possible, thereby avoiding contact of the base material with the transport roll. However, this method is difficult to apply when a functional layer is formed or transported under vacuum.

  Therefore, for example, a technique described in Patent Document 1 is known in order to be applicable even under vacuum. In the technique described in Patent Document 1, unlike a normal smooth conveyance roll (flat roll), the portion where the functional layer is formed does not come in contact, and the base material is used in a portion other than the portion where the functional layer is formed. The conveyance roll to hold | maintain is used. This roll is called, for example, a stepped roll (sometimes called a stepped roll).

  The stepped roll is in contact with the base material at a portion other than the portion where the functional layer is formed in the width direction, which is a direction orthogonal to the transport direction of the base material. In such a state, a portion where the substrate is supported and a portion where the substrate is not supported are generated in the width direction of the substrate. And if the area | region where a process is performed is arrange | positioned in the part in which this base material is not supported, it can suppress that the function of the functional layer by the contact of a conveyance roll is impaired.

  However, when the base material is conveyed by the stepped roll, the base material is easily deformed in a portion that is not particularly supported. Therefore, Patent Document 2 describes a manufacturing apparatus that detects the degree of deformation of such a base material and determines the barrier performance of the barrier film portion where the deformation has occurred.

JP 2011-241015 A JP 2011-184790 A

  In Patent Document 2, although reference is made to deformation of the base material, no method for preventing the deformation of the base material is disclosed at all. Therefore, the technique described in Patent Document 2 is still insufficient as a technique for preventing the deformation of the base material.

  When a stepped roll is used as the transport roll, the base material is likely to be deformed as described in Patent Document 2, particularly in a portion not supported by the transport roll. According to the study by the present inventors, this deformation is caused by friction between the base material and the transport roll in the portion supported by the transport roll, but no friction occurs in the unsupported portion. It is thought to be due to. Therefore, when tension is applied in the conveyance direction of the base material, wrinkles and bending are particularly likely to occur at unsupported portions where friction does not occur. And if a base material deform | transforms, processing, such as formation of a functional layer, will be performed with respect to such a deformed base material, and organic EL may be reduced due to a decrease in positional accuracy, film thickness accuracy, and accuracy performed. The performance of the device is degraded.

  Therefore, when such a stepped roll is used, it is preferable to lower the tension on the substrate as compared with the case where a flat roll is used. If the tension is lowered, it is possible to suppress deformation particularly in a portion not supported by the transport roll.

  However, when the tension of the base material becomes low, sagging or bending of the base material may occur. Thereby, the flatness of a base material may fall. Therefore, if the functional layer is formed in a state where the planarity of the substrate is deteriorated, for example, the film thickness distribution of the functional layer may be non-uniform. That is, the accuracy of the functional layer thickness decreases.

  Furthermore, when forming a functional layer, for example as a process with respect to a base material, a temperature control plate etc. may be installed in the vicinity of a base material, and the temperature of a base material may be controlled. In such a case, if the flatness is deteriorated due to sagging of the base material or the like, the temperature control of the base material by the temperature control plate may not be performed uniformly. As a result, the temperature of the base material cannot be accurately adjusted, and a temperature distribution may occur in a region where the functional layer is formed. For this reason, the desired functional layer is not formed, and the function originally performed by the functional layer is not sufficiently generated, or the performance of the functional layer varies.

  These problems become significant when the substrate has flexibility. In particular, the organic EL element often requires precision in the functional layer or the like. Therefore, if such a problem exists at the time of processing the base material, for example, when the functional layer is formed, in addition to a decrease in positional accuracy, temperature non-uniformity, and the like, non-uniform thickness distribution of the functional layer occurs. Accordingly, for example, the luminance distribution is likely to be nonuniform when the produced organic EL element is used. Of course, in order to solve these problems, it is conceivable to transport the base material with high tension. However, if so, the deformation of the base material is likely to occur as described above. Thereby, for example, it becomes easy to cause an increase in the non-light emitting area during light emission.

  The present invention has been made in view of the above problems. Thus, the problem to be solved by the present invention is to provide a method for producing an organic electroluminescence element that enables processing such as formation of a functional layer with high accuracy even when a stepped roll is used during vacuum conveyance. It is.

  The gist of the present invention is as follows.

1. An organic process is carried out in a manufacturing apparatus comprising a plurality of transport rolls including stepped rolls that are capable of transporting the belt-like base material in a state where convex parts are formed in the rotation direction and the flexible belt-like base material is in contact with the convex parts. A method for producing an electroluminescent device, comprising:
Under vacuum, the first tension was applied to the band-shaped substrate in the conveying direction of the band-shaped substrate, and the belt-shaped substrate was conveyed while contacting at least the stepped roll, and the first tension was applied. In a state, a base material transport process for transporting the belt-shaped base material to a predetermined position;
After the belt-shaped base material is transported to the predetermined position and the transport of the belt-shaped base material is stopped , the tension applied to the belt-shaped base material is stopped in a state where the transport of the belt-shaped base material is stopped. A tension increasing step of changing to a second tension having a magnitude of 1.5 to 2.5 times the first tension;
The base material that stops the transport of the belt-like base material and performs the processing on the belt-like base material in a state where the second tension having a magnitude different from the first tension is applied to the belt-like base material. A method for producing an organic electroluminescence device, comprising: a treatment step.

  2. 2. The method for producing an organic electroluminescent element according to 1 above, wherein at least one of the tension increasing step and the substrate treatment step is performed under vacuum conditions.

3. The substrate processing step is performed in a vacuum,
3. The method for producing an organic electroluminescent element according to 1 or 2, wherein the treatment in the substrate treatment step is at least one of surface modification of the belt-like substrate and formation of a functional layer.

  ADVANTAGE OF THE INVENTION According to this invention, even if it is a case where a stepped roll is used at the time of vacuum conveyance, the manufacturing method of the organic electroluminescent element which enables processing, such as formation of a functional layer, can be provided accurately.

It is a flow of the manufacturing method of the organic electroluminescent element which concerns on this embodiment. It is a manufacturing apparatus of the organic electroluminescent element which concerns on this embodiment. It is a figure for demonstrating the tension | tensile_strength raising process in the manufacturing method of the organic electroluminescent element which concerns on this embodiment. It is a figure which shows the dimension of the stepped roll used in the Example.

  Hereinafter, a form (this embodiment) for carrying out the present invention will be described. However, the present embodiment is not limited to the following contents, and can be implemented with any changes without departing from the gist of the present invention.

  Hereinafter, first, the manufacturing method of the organic electroluminescence element according to the present embodiment will be described, and then the configuration of the organic electroluminescence element that can be manufactured by the manufacturing method will be described.

[1. Manufacturing method of organic electroluminescence element]
In the method of manufacturing an organic electroluminescence element according to the present embodiment (hereinafter referred to as “organic EL element” as appropriate), a convex portion is formed in the rotation direction, and a flexible strip-shaped substrate is in contact with the convex portion. It is a method of manufacturing an organic EL element performed in a manufacturing apparatus including a plurality of transport rolls including a stepped roll capable of transporting a belt-shaped substrate.

  The manufacturing method of the organic EL device according to the present embodiment applies a first tension to the belt-like substrate in the transport direction of the belt-like substrate under vacuum, and contacts the belt-like substrate with at least the stepped roll. A base material transporting step for transporting the belt-shaped base material to a predetermined position in a state where the first tension is applied, and transporting the belt-shaped base material to the predetermined position. A tension increasing step of changing a tension applied to the belt-like base material to a second tension having a magnitude of 1.5 to 2.5 times the first tension after the conveyance of the material is stopped; And a base material processing step of performing processing on the belt-like base material in a state where the second tension is applied to the belt-like base material.

  FIG. 1 is a flow of a method for manufacturing an organic EL element according to this embodiment. FIG. 2 shows an organic EL element manufacturing apparatus according to this embodiment. The flow shown in FIG. 1 can be executed by the manufacturing apparatus 100 shown in FIG. 2, for example.

A manufacturing apparatus 100 shown in FIG. 2 has a convex portion (not shown in FIG. 2, for example, see FIG. 3) formed in the rotation direction, and a flexible belt-like substrate 50 (hereinafter simply referred to as “ Stepped rolls 20a to 20j capable of transporting the base material 50 when tension is applied in a state in which the base material 50 "is in contact with the base material 50". Moreover, the manufacturing apparatus 100 is provided with cylindrical flat rolls 30a to 30n having a smooth surface and capable of conveying the base material 50 and the protective film 51 with tension applied in a state where the base material 50 is in contact. When the substrate 50 is conveyed in a state where tension is applied, the stepped roll 20 and the flat roll 30 are rotated by friction with the substrate 50.
Hereinafter, “stepped rolls 20a to 20j” are collectively referred to as “stepped rolls 20” as appropriate, and “flat rolls 30a to 30n” are collectively referred to as “flat rolls 30” as appropriate.

  Further, when the stepped roll 20 and the flat roll 30 are referred to without distinction, they are referred to as “conveying rolls”. When a reference sign indicates a specific roll, the same reference sign as that of the specific roll is attached. Specifically, for example, the “step roll 20a” may be referred to as a “transport roll 20a”.

The manufacturing apparatus 100 includes an unwinding chamber 1 for unwinding the substrate 50 from a flexible belt-shaped substrate roll 11 (hereinafter simply referred to as “roll 11”) on which an anode is formed, and a direction perpendicular to the conveyance direction of the substrate 50. And a conveyance auxiliary chamber 2 in which a mechanism that does not cause a positional deviation in the direction of movement, a movement distance correction mechanism in the conveyance direction, and the like are arranged.
In addition, the manufacturing apparatus 100 includes a first film forming chamber 3 for depositing a material constituting each functional layer of the organic EL element on the base material 50, and a transport auxiliary chamber having the same configuration as the transport auxiliary chamber 2. 4 and a second film forming chamber 5 for forming another functional layer on the functional layer formed in the first film forming chamber 3.

Furthermore, the manufacturing apparatus 100 affixes the transport auxiliary chamber 6 having the same configuration as the transport auxiliary chambers 2 and 4 and a protective film 51 from the roll 12 for protecting the film formed on the substrate 50. Laminating chamber 7.
In addition, the manufacturing apparatus 100 is configured to wind the roll 13 around the conveyance auxiliary chamber 8 having the same configuration as the conveyance auxiliary chambers 2, 4, and 6 and the organic EL sheet 52 obtained by laminating the protective film 51. And a take-up chamber 9.

  In the present embodiment, the atmosphere in these chambers 1 to 9 is controlled according to the processing performed in the chamber. Specifically, the first film formation chamber in which the functional layer is formed (base material treatment step), the tension applied to the base material 50 is changed (tension increase step), and the base material is transported (base material transport step). 3 and the 2nd film-forming chamber 5 are evacuated. Further, the auxiliary transfer chambers 2, 4, 6, and 8 in which the base material is transported (base material transport process) are also in a vacuum. The laminating chamber 7 has an inert atmosphere (for example, under nitrogen gas). Further, the unwinding chamber 1 and the winding chamber 9 are under the atmosphere. In particular, in the present embodiment, a chamber (a first film forming chamber 3 and a second film forming chamber 5, and auxiliary transfer chambers 2, 4, 6, 8 provided with a stepped roll and in which a substrate transport process is performed). ) Is in a vacuum.

  Further, regarding the arrangement of the transport rolls, a step roll 20 or a flat roll 30 is provided according to the arrangement side of the functional layer formed in the first film formation chamber 3 and the second film formation chamber 5. That is, although details will be described later with reference to FIG. 3B, the step roll 20 is provided so as to come into contact with the functional layer forming surface on the substrate 50. At this time, the formed functional layer passes between the convex portions of the stepped roll 20, and the functional layer of the base member 50 is brought into contact with the portion where the functional layer is not formed and the upper surface of the convex portion of the base member 50. It does not come into contact with the transport roll unintentionally. Moreover, the flat roll 30 is provided so that the surface on the opposite side of the functional layer formation surface on the base material 50 may be contacted.

  The core of the roll 11 provided in the unwinding chamber 1 and the core of the roll 13 provided in the winding chamber 9 are not deformed when the substrate 50 is wound up, and the atmosphere is about 150 ° C. Those that do not deform even when exposed are preferred. Further, it is preferable that the winding core does not generate dust when being attached to and detached from the manufacturing apparatus 100 or transferred to the decompression chamber or the like. Furthermore, it is preferable that the part which the base material 50 touches among the surface parts of a winding core is smooth, specifically, it is preferable that surface roughness Ra is 30 nm or less, and Rt is 100 nm or less. The material of the winding core is preferably glass fiber reinforced plastic or stainless steel.

  Furthermore, in order to prevent the web surface on the core and the back surface of the web overlying from rubbing against each other in the axial direction both ends of the winding core of the base material 50, You may give a knurling process (it is also called embossing). This height is preferably about 2 to 50 μm, for example.

  Hereinafter, the manufacturing method of the organic EL element according to this embodiment will be described mainly with reference to FIGS. 1 and 2. In the following description, the number of chambers in which the functional layers are formed is two chambers, the first film formation chamber 3 and the second film formation chamber 5, for the sake of simplicity of description. However, this can be changed as appropriate according to the number and type of functional layers to be formed.

  In addition, the formation of the functional layer in the first film formation chamber 3 and the formation of the functional layer in the second film formation chamber 5 are performed on the same substrate 50. Specifically, the formation of the functional layer in the first film formation chamber 3 and the formation of the functional layer in the second film formation chamber 5 are performed on different functional layer pattern application areas 50a (described later) on the substrate 50. At the same time. However, in the following description, for convenience of explanation, only one functional layer pattern application area 50a will be focused on, and the processing performed on the one functional layer pattern application area 50a will be mainly described.

  First, the base material 50 is unwound from the roll 11 installed in the unwinding chamber 1, and tension (tension during conveyance, first tension) is applied to the entire base material 50 (first tension). Giving step; step S101). Thereby, the slack of the base material 50 is eliminated, and the preparation for transporting the base material is completed. Since the tension at this time varies depending on the thickness of the base material 50 and the like, it cannot be said unconditionally. For example, when the thickness is 120 μm, the tension per 1 m width of the base material 50 can be more stably conveyed. , Usually 30N or more, preferably 50N or more, and usually 150N or less, preferably 120N or less. The base material 50 is previously subjected to anode (electrode) patterning.

  Next, the base material 50 is transported in a state where tension (tension during transport) is applied to the base material 50 (that is, in a state where no slack or the like is generated) (base material transporting step; step S102). Specifically, the base material 50 is arranged such that a position where the functional layer is desired to be formed in the base material 50 (a functional layer pattern application area 50a described later, see FIG. 3A) is in the first film forming chamber 3. Is transported. After the base material 50 is transported to a predetermined position, the transport of the base material 50 is stopped (a transport stop process; step S103). Note that, at this time, the tension at the time of conveyance remains applied and no sagging occurs.

  And the control which raises the tension | tensile_strength to apply is performed in the base material 50 which has stopped conveyance in the 1st film-forming chamber 3 (tensile raising process; step S104). Specifically, in step S <b> 104, a tension (treatment tension, second tension) larger than the tension (transport tension, first tension) applied in step S <b> 101 is applied to the substrate 50. This point will be described with reference to FIG.

  FIG. 3 is a diagram for explaining a tension increasing step in the method of manufacturing an organic electroluminescence element according to this embodiment. FIG. 3 also shows an enlarged view of each means installed in the first film formation chamber 3.

  The substrate 50 is conveyed, and the conveyance is stopped when the functional layer pattern application area 50a of the substrate 50 is positioned between the conveyance rolls 30c and 30d. At this time, the conveyance tension applied in step S101 is applied to the base material 50 as it is. The functional layer pattern application area 50a is shown in a simplified manner in order to make it easier to grasp the invention.

  In this state, the flat rolls 30c and 30d (conveying rolls) are slightly moved in the lower left direction (flat roll 30c) and the lower right direction (flat roll 30d) by driving means (not shown) (see FIG. 3A). ). At this time, since the base material 50 is stopped, the position of the base material 50 does not change. Then, with the movement of the flat rolls 30c and 30d, the tension applied to the base material 50 rises and changes, and a new tension (processing tension) is applied (step S104). As described above, the newly applied processing tension is larger than the transporting tension (see FIG. 3B). Then, a functional layer is formed (that is, formed into a film) in the functional layer pattern application area 50a of the substrate 50 in a state where the processing tension is applied (first film forming step; step S105).

  Here, the relationship between the conveyance tension (first tension) applied in step S101 and the processing tension (second tension) newly applied in step S104 will be described. In this embodiment, when the transport tension applied in step S101 is TR and the processing tension newly applied in step S104 is TS, the value obtained by dividing TS by TR (TS / TR) is usually 1. It is 5 or more, preferably 1.7 or more, more preferably 1.75 or more, further preferably 2 or more, and usually 2.5 or less, preferably 2.25 or less. In other words, in the present embodiment, during film formation while the conveyance of the base material 50 is stopped, a processing tension having a magnitude obtained by multiplying the tension during conveyance by a coefficient included in these ranges is newly applied. By controlling the processing tension so as to be in this range, the functional layer can be formed with high accuracy. Thereby, the performance of the obtained organic EL element can be made favorable.

  Further, as shown in FIG. 3B, below the base material 50, the vapor deposition source 3 a from which the vapor deposition material for forming the functional layer is released, and the lower surface of the base material 50 (the stepped roll 20 contacts). A finely adjustable pattern forming mask 3b (hereinafter referred to as "mask 3b") for forming a functional layer having a desired pattern is disposed on the surface to be formed. Further, a temperature adjustment plate 3c for maintaining the temperature of the substrate 50 during vapor deposition is disposed above the substrate 50.

  Vapor deposition (film formation) on the substrate 50 is performed as follows. That is, first, the vapor deposition source 3a is adjusted and maintained so that the vapor deposition material is discharged at a predetermined vapor deposition rate, and is blocked by a shutter (not shown) or the like so as not to adhere to the base material 50 unintentionally. Yes. The base material 50 is provided with a mark for the functional layer pattern application area 50a by providing an alignment mark (not shown). The first film forming chamber 3 is provided with a camera (not shown) and the like for reading the mark. Thereby, the base material 50 stops after being conveyed at an arbitrary speed to a predetermined position where the camera can read the alignment mark. Thereafter, as described above, a processing tension greater than the transport tension is applied to the substrate 50.

  Next, with this processing tension applied, the alignment mark is read by the camera, and the mask 3b is finely adjusted to match the position of the alignment mark. Thereafter, the temperature adjustment plate 3c is lowered and comes into close contact with the base material 50, while the mask 3b is raised and stops at the close contact or a position where a slight gap is provided.

  Then, the shutter of the vapor deposition source 3a is opened, and the functional layer is formed in a pattern on the substrate 50. At this time, the deposition time and the like are controlled so that the determined film thickness is obtained, and the shutter is closed when the determined film thickness is obtained. Thereafter, the mask 3b is lowered and returned to the reference position, and the temperature adjustment plate 3c is also raised and returned to the reference position. And the tension | tensile_strength with respect to the base material 50 is returned even to conveyance tension | tensile_strength by returning the flat rolls 30c and 30d to the original position shown to Fig.3 (a) (step S106; tension return process). Thereafter, the conveyance of the substrate 50 is resumed (step S107; substrate conveyance step).

  When the transfer is resumed, the functional layer pattern application area 50a of the substrate 50 is transferred to the second film forming chamber 5 via the transfer auxiliary chamber 4, and then stopped (step S108; transfer stop step). Then, in the second film forming chamber 5, metal deposition is performed in the same manner as in the first film forming chamber 3, and a cathode is formed (cathode forming process) (step S109; tension increasing step, step S110; first). 2 film-forming process and step S111; tension return process).

  Thereafter, the substrate 50 is conveyed again (step S112; substrate conveying step), and the functional layer pattern application area 50a of the substrate 50 is sent to the laminating chamber 7 via the conveyance auxiliary chamber 6. In the laminating chamber 7, the protective film 51 is attached so as to cover the cathode surface while the base material 50 is conveyed (step S <b> 113; laminating step). Thereby, the organic EL sheet 52 is obtained. Then, the organic EL sheet 52 obtained by laminating is conveyed to the winding chamber 9 via the conveyance auxiliary chamber 8 and is wound on the roll 13. Finally, the organic EL element is obtained by unwinding from the roll 13 as necessary and cutting it into a predetermined size. Finally, application of the tension at the time of conveyance to the base material 50 at the time of conveyance is released (step S114; first tension release step), and a series of flows is completed.

  Thus, in the manufacturing apparatus 100 which concerns on this embodiment, the step roll 20 is provided in the contact surface side of the functional layer as a conveyance roll. When the conveyance is stopped and the functional layer is formed, the processing tension applied to the base material 50 is controlled to be larger than the conveyance tension. Thereby, the bending of the base material 50 can be more reliably and easily prevented. Therefore, processing such as formation of a functional layer can be performed with high accuracy, and an organic EL element with good performance can be obtained.

  The manufacturing apparatus 100 shown in FIG. 2 manufactures an organic EL element by a roll-to-roll method using a plurality of transport rolls including the step roll 20. Specifically, as described above, a submicron function is provided on the base material 50 while the flexible base material 50 wound in a roll shape is unwound from the roll 11 and intermittently conveyed. A layer (functional material layer) is formed, or a part or all of the organic EL structure (functional layer, electrode, etc.) is formed, and is wound around the roll 13 again. The base material 50 wound around the roll 11 may be referred to as “original winding” including the winding core. Moreover, when representing a part of the base material 50 during conveyance, it may also be called a web. Specifically, for example, although not shown, the transparent conductive layer is drawn out in a vacuum film forming apparatus, and after film formation by sputtering or the like at one place or a plurality of places, it is wound in a vacuum.

  Further, after forming the functional layer in vacuum, the protective film 51 is laminated in vacuum, or the vacuum is returned to normal pressure through one or more stages of decompression chambers, and then the protective film 51 is laminated. Also when it winds up after that, it is called a so-called roll-to-roll system.

  In addition, after the organic EL sheet 52 is obtained by laminating with the protective film 51, a manufacturing process in which the sheet is cut and cut without being taken up even if flexible. May be taken. As a result, an organic EL element can be obtained without the roll 13, but in this case, it is also called a roll-to-roll system in a broad sense. Also, when the web is conveyed in the web state until it is returned to atmospheric pressure after lamination, it is called a roll-to-roll system in a broad sense. Thus, performance, quality, productivity, etc. can be improved by conveying the processing surface side substantially non-contact.

  The method for manufacturing the organic EL element according to the present embodiment has been described above, but the method for manufacturing the organic EL element according to the present embodiment is not limited to the above example.

  For example, the configuration of the manufacturing apparatus 100 is merely an example, and may be any configuration as long as the manufacturing method according to the present embodiment is applicable.

  Further, for example, as a method for increasing the processing tension from the conveying tension, in this embodiment, the flat roll 30 is moved as shown in FIG. 3, but the tension increasing method is not limited to the illustrated method. . For example, a dancer roll may be used, or the tension may be controlled using a brake or the like.

  Further, in the illustrated example, the processing for forming the functional layer is performed after the conveyance of the base material 50 is stopped. However, the processing performed on the base material 50 is not limited to this, and any processing can be performed in the same manner. it can. For example, the surface modification of the substrate 50 can be performed with high accuracy by stopping the surface of the substrate 50 after the conveyance of the substrate 50 is stopped. Furthermore, the present invention is not limited to one type of process, and a plurality of processes may be performed.

  In the above example, in addition to the base material transport step, the tension applying step and the base material processing step are also performed in a vacuum. However, if the base material transport step is performed in a vacuum, it is not limited thereto, and the tension rises. The process and the substrate treatment process are not necessarily performed in a vacuum.

[2. Organic EL device]
Next, an organic EL element that can be manufactured by the manufacturing method according to the present embodiment (hereinafter, appropriately referred to as “organic EL element according to the present embodiment”) will be described. The organic EL device according to this embodiment is one in which electrodes and various functional layers are formed on a substrate.

  The base material (support) provided in the organic EL element according to the present embodiment is a flexible strip. As the flexible substrate, for example, a transparent resin film (plastic film) is preferable. Specifically, the thickness is, for example, 10 μm or more, preferably 30 μm or more, 250 μm or less, preferably 200 μm or less, and can be wound around a core (also referred to as a core) having an outer diameter of 7.7 cm to 30 cm. A film made of a polymer organic material (also referred to as a sheet when relatively thick) is preferable.

  More specifically, for example, polyester films such as polyethylene terephthalate (PET) and 2,6-polyethylene naphthalate (PEN), polycarbonate, polyetheretherketone, polysulfone, polyethersulfone (PES), tetrafluoroethylene-par Examples thereof include a plastic film such as a fluoroalkyl vinyl ether copolymer, polycarbonate, polyurethane, polyimide, polyetherimide, polyimide, and polypropylene.

  The base material is desirably a uniform continuous film, but it may be formed by joining (splicing) the ends of different or similar base materials. In this case, the joining portion is preferably joined with an adhesive tape thinner than the base material so as not to break during transportation. The transparency of the substrate is not particularly limited, but when an organic EL element is configured, a so-called transparent or translucent material having a visible light transmittance of 50% to 99% is preferable. It may be a laminate of a plurality of polymer materials. As the substrate, a laminated film described in JP-A-2005-38661 can also be used.

  Moreover, it is preferable that the gas barrier layer is formed in the base-material surface. That is, although details will be described later, a gas barrier layer is preferably formed between the functional layer formed on the substrate and the substrate. Thereby, it is possible to prevent gas components such as moisture and oxygen that may affect the electrical function of the functional layer such as the light emitting layer from reaching the functional layer.

The gas barrier layer is, for example, an inorganic vapor deposition film, and examples thereof include a moisture-proof layer having a water vapor transmission coefficient of 1 × 10 ⁻¹⁴ g · cm / (cm ² · sec · Pa) or less. By using such a substrate, gas permeability such as water vapor permeability from the substrate to the functional layer can be reduced. In addition, this makes it possible to prolong the drive life in a normal atmosphere (so-called normal temperature and normal humidity environment), and a good organic EL element can be obtained.

  Examples of the material capable of constituting the gas barrier layer include a ceramic vapor-deposited layer such as silicon oxide and aluminum oxide, a moisture-proof layer having a structure in which these ceramic layers and an impact relaxation polymer layer are alternately laminated, and a metal foil. Examples thereof include copper (Cu) foil and aluminum (Al) foil. A plurality of these may be stacked.

  The thickness of the gas barrier layer can be, for example, about 0.02 μm or more, preferably about 6 μm or more, and about 50 μm or less, preferably about 20 μm or less. The gas barrier layer can be formed, for example, by sputtering, plasma CVD (chemical vapor deposition) or the like.

  In addition, the gas barrier layer is preferably formed on the outer surface of the protective film described with reference to FIG. 2 or formed by laminating a protective film having equivalent performance. Examples of the form in which the gas barrier layer is formed on the outer surface of the protective film include a form in which a film having gas barrier properties is laminated on the outer surface of the protective film. As a film having such a gas barrier property, for example, a vapor-deposited film using PET as a base material such as a GX film manufactured by Toppan Printing Co., Ltd. can be mentioned. In laminating, for example, a thermosetting adhesive or a photocurable adhesive can be applied.

  Furthermore, you may make it form a gas barrier layer on the cathode before sticking a protective film, and stick a protective film after that. When a protective film is stuck after forming a gas barrier layer, a protective film may be stuck in a vacuum and may be stuck under atmospheric pressure. However, in this case, an inert gas atmosphere such as under a nitrogen stream is preferable.

  As described above, in the organic EL element according to this embodiment, the electrode and the functional layer are formed on the base material. Such a functional layer is usually an organic layer. Therefore, the organic EL element according to the present embodiment is usually formed by laminating one or a plurality of organic layers between a pair of electrodes arranged between the base material and the protective film.

  Specific examples of the configuration of the organic layer include a configuration of anode / hole injection / transport layer / light emitting layer / electron injection / transport layer / cathode. Further, the simplest configuration includes an anode / light emitting layer / cathode. In addition to these layers, an electron blocking layer, a hole blocking layer, a buffer layer, and the like are appropriately provided. The thickness of each organic layer and each thin film ranges from 1 nm to several μm, and the light emitting material in the layer emits light by injecting carriers from the electrodes. Each layer is configured so that carriers such as holes and electrons injected from both electrodes are smoothly moved.

  Each organic layer that can constitute the organic EL element will be described.

  Among the organic layers that can constitute the organic EL element, various fluorescent substances can be applied to the light emitting material (film forming material) contained in the light emitting layer. Such a light emitting material is not particularly limited, for example, aromatic heterocyclic compounds such as carbazole, carboline, diazacarbazole, triarylamine derivatives, stilbene derivatives, polyarylene, aromatic condensed polycyclic compounds, Aromatic hetero-fused ring compounds, metal complex compounds, etc., and single oligo compounds or composite oligo compounds thereof may be mentioned.

  Moreover, it is preferable that about 0.1 mass%-about 20 mass% dopant material contain in a light emitting layer. Examples of the dopant include known fluorescent dyes such as perylene derivatives and pyrene derivatives, and in the case of phosphorescent light emitting layers, for example, tris (2-phenylpyridine) iridium, bis (2-phenylpyridine) (acetylacetate). Complex compounds such as ortho-metalated iridium complexes represented by natto iridium, bis (2,4-difluorophenylpyridine) (picolinato) iridium, etc. can be contained in an amount of about 0.1 to 20% by mass together with the light emitting material. It is.

  Although the light emission method of the organic EL element is not particularly limited, for example, a phosphorescence light emission method is preferable. The phosphorescence emission method is considered to have a light-emitting region inside the light-emitting layer, and it is relatively difficult for light emission to occur. This causes the phenomenon that unevenness at the bonding interface, which is the biggest difficulty of the bonding method, and carrier movement are slow. It is difficult and preferable.

  Examples of materials used for the hole injection / transport layer include phthalocyanine derivatives, heterocyclic azoles, aromatic tertiary amines, polyvinyl carbazole, polyethylenedioxythiophene / polystyrene sulfonic acid (PEDOT: PSS), and other conductive materials. Carbazole-based light-emitting materials such as 4,4′-dicarbazolylbiphenyl and 1,3-dicarbazolylbenzene used for the light-emitting layer, (di) aza Low molecular light emitting materials represented by pyrene-based light emitting materials such as carbazoles, 1,3,5-tripyrenylbenzene, polymer light emitting materials represented by polyphenylene vinylenes, polyfluorenes, polyvinyl carbazoles, etc. Can be mentioned.

  Examples of the electron injection / transport layer material include metal complex compounds such as 8-hydroxyquinolinate lithium and bis (8-hydroxyquinolinate) zinc, and the following nitrogen-containing five-membered ring derivatives. That is, oxazole, thiazole, oxadiazole, thiadiazole or triazole derivatives are preferred. Specifically, 2,5-bis (1-phenyl) -1,3,4-oxazole, 2,5-bis (1-phenyl) -1,3,4-thiazole, 2,5-bis (1 -Phenyl) -1,3,4-oxadiazole, 2- (4′-tert-butylphenyl) -5- (4 ″ -biphenyl) 1,3,4-oxadiazole, 2,5-bis ( 1-naphthyl) -1,3,4-oxadiazole, 1,4-bis [2- (5-phenyloxadiazolyl)] benzene, 1,4-bis [2- (5-phenyloxadiazolyl) -4-tert-butylbenzene], 2- (4'-tert-butylphenyl) -5- (4 "-biphenyl) -1,3,4-thiadiazole, 2,5-bis (1-naphthyl) -1 , 3,4-thiadiazole, 1,4-bis [2- (5-phenyl) Asiazolyl)] benzene, 2- (4′-tert-butylphenyl) -5- (4 ″ -biphenyl) -1,3,4-triazole, 2,5-bis (1-naphthyl) -1,3,4 -Triazole, 1,4-bis [2- (5-phenyltriazolyl)] benzene and the like.

  The thickness of each organic layer is not particularly limited, but is, for example, 0.05 μm or more, preferably 0.1 μm or more, and 0.3 μm or less, preferably 0.2 μm or less. The organic layer can be formed by, for example, a vapor deposition method, a coating method, a printing method, or the like.

  Of the electrode materials, the conductive material used for the anode for injecting holes is preferably a material having a work function larger than 4 eV, for example. Specifically, for example, silver, gold, platinum, palladium and the like and alloys thereof, metal oxides such as tin oxide, indium oxide and ITO (indium tin oxide), and organic conductive resins such as polythiophene and polypyrrole, etc. Can be mentioned. Especially, it is preferable that it is translucent, and specifically ITO which is a transparent electrode is preferable. As a method for forming the ITO transparent electrode, for example, sputtering, mask vapor deposition, photolithography patterning, and the like are applicable, but are not limited thereto.

  Moreover, as a conductive substance used for the cathode, for example, a material having a work function smaller than 4 eV is preferable. Specifically, for example, magnesium / silver, lithium / aluminum, and the like are typical examples of alloys such as magnesium and aluminum. In addition, sputtering, mask vapor deposition, photolithography patterning, plating, printing, and the like can be applied as the formation method, but the method is not limited to these.

  In addition, the said organic EL element is a monochromatic or white organic EL element for illumination, for example. However, the light emitting layer of the organic layer can be formed by patterning for each of three colors of red, green and blue, and a drive circuit can be incorporated to obtain a full color display.

  Hereinafter, the present embodiment will be described more specifically with reference to examples.

<Production of organic EL element>
In accordance with the flow shown in FIG. 1, an organic EL element was produced using the manufacturing apparatus 100 shown in FIG.
First, on a strip-like polyethylene terephthalate film (PET film; base material) having a width of 1000 mm and a thickness of 120 μm, a gas shielding film (barrier film) is 80 nm on the organic EL film formation surface (surface on which a functional layer is formed). A film having a thickness of 130 nm and an ITO film formed on the entire surface was prepared. The ITO film is patterned in a transport direction of 280 mm and a direction (width direction) 280 mm perpendicular to the transport direction. The surface resistivity of the ITO film was 40Ω / □. Incidentally, this patterned ITO film corresponds to the “functional layer pattern application area 50a” described with reference to FIG. 3 (however, in FIG. 3, one is arranged in the width direction for simplification of description. Only.)

  Adjacent, patterned ITO films (that is, “functional layer pattern application area 50a”) in the transport direction are secured in advance by portions sandwiched by gates for forming a differential pressure in each chamber of the manufacturing apparatus 100. Therefore, it was set to 60 mm. Moreover, the space | interval of the width direction was provided 50 mm at a time (30 mm from the film both ends).

  This was wound to obtain a roll 11, and the obtained roll 11 was set in the unwind chamber 1 of the manufacturing apparatus 100 shown in FIG. And the tension | tensile_strength at the time of conveyance of 100 N / base-material width (1st tension demonstrated referring FIG. 1) was provided with respect to the base material 50 of the roll 11, and the driving | operation of the manufacturing apparatus 100 was started. The dimensions of the stepped roll 20 used in the manufacturing apparatus are as shown in FIG.

  In the first film formation chamber 3 shown in FIG. 2, after the conveyance of the base material 50 from the roll 11 is stopped, the tension at the time of conveyance applied to the base material 50 is equal to or higher than the tension at the time of conveyance. (The second tension described with reference to FIG. 1). Then, the material which comprises a functional layer was vapor-deposited in the state by which the tension | tensile_strength at the time of this process was maintained. The magnitude of the processing tension is described later in Table 1 together with the experimental results. After that, the tension was returned to the tension at the time of conveyance, and the substrate 50 was conveyed and used for the subsequent second film forming chamber 5.

The materials deposited in the first film forming chamber 3 include α-NPD (thickness 40 nm), CBP (containing 6 mass% of Ir (ppy) ₃ as a co-deposition component) (thickness 35 nm), BAlq (thickness). 5 nm), Alq ₃ (thickness 40 nm), and lithium fluoride (thickness 0.5 nm). These were deposited on the substrate 50 in this order. The structural formula of the material used for vapor deposition is shown below.

  In the second film forming chamber 5, aluminum was deposited by 110 nm. The formation of the electrode in the second film formation chamber 5 was performed in the same manner as the formation of the functional layer in the first film formation chamber 3. That is, after the conveyance of the base material 50 is stopped, the tension applied to the base material 50 is changed to the same tension as the processing tension changed in the first film formation chamber 3, and then the tension is changed. In a maintained state, the material constituting the functional layer was deposited. Thereafter, the tension was returned to the tension during conveyance, and the base material 50 was conveyed and used for the subsequent laminating chamber 7.

  In the laminating chamber 7, a PET film (80 μm in thickness as the thickness of the PET film) on which the gas barrier layer has been applied, in which the sealing resin (adhesive) is applied at a thickness of 40 μm, was laminated in a nitrogen stream. The gas barrier layer formed on the PET film is the same as the gas barrier layer formed on the PET film wound around the roll 11. Thereby, the organic EL sheet 52 was obtained, and the obtained organic EL sheet 52 was wound around the roll 13 in the winding chamber 9 to produce an organic EL element that emits green phosphorescence.

<Characteristic evaluation about the produced organic EL element>
(1) Evaluation of non-light emitting area The element light emitting portion of the produced organic EL element is photographed with a digital image, the image is binarized using image processing software, and the area ratio between the light emitting portion and the non-light emitting portion is calculated. The obtained area ratio was evaluated according to the following criteria.
A: Area ratio is 1% or less (light emission over the entire surface is very good)
○: The area ratio is larger than 1% and 2% or less (most of the light is emitted and is good)
Δ: Area ratio is larger than 3% and 10% or less (light is emitted, but there is a portion where light is not emitted)
X: The area ratio is larger than 10% (the portion that does not emit light is conspicuous)

(2) Evaluation of luminance distribution (light emission unevenness) The produced organic EL device emits light at 1000 cd / m ² at room temperature, and the luminance distribution is measured with a two-dimensional color luminance meter CA-2000 (manufactured by Konica Minolta Optics). did. Then, the difference between the maximum value and the minimum value of the luminance in the element light emitting part was divided by 1000 cd / m ² , and the obtained value was evaluated according to the following criteria.
A: Value is less than 5% (light emission is particularly uniform over the entire surface, and no visible light emission unevenness occurs)
○: The value is 5% or more and less than 10% (light is emitted uniformly over the entire surface, and light emission unevenness hardly occurs).
Δ: Value is 10% or more and less than 15% (light is emitted uniformly over almost the entire surface, but uneven light emission is found in some places)
X: Value is 15% or more (difference in emission intensity is conspicuous and uneven emission is observed)

  About the above result, it shows in Table 1 with the tension at the time of conveyance, and the tension at the time of a process. In Table 1, the item of tension indicates the tension applied per 1 m of substrate width in the axial direction (that is, the direction perpendicular to the conveying direction). In Tables 1 and 2, “(treatment tension) / (transport tension)” is a value obtained by dividing the treatment tension by the transport tension.

  Further, the organic EL element was prepared in the same manner as described above except that the thickness of the PET film was 150 μm, the transport tension was 150 N / base material width, and the treatment tension was changed according to the transport tension. Prepared and evaluated. The results are shown in Table 2 together with the tension during processing.

  As shown in Table 1 and Table 2, when the value obtained by dividing the processing tension by the transport tension was 1.5 or more and 2.5 or less, the non-light emitting area and the luminance distribution were good. . That is, when such a condition was satisfied, an organic EL element in which the area of the portion that did not emit light was small and light emission unevenness was small was obtained. In particular, a better result was obtained when the value of (tension during processing) / (tension during conveyance) was about 2 or more and 2.5 or less. Therefore, it was found that the processing tension is preferably about 2 to 2.5 times the transport tension.

  In addition, the relationship between the magnitudes of tension ((tension during processing) / (tension during conveyance)) shows the same tendency regardless of whether the substrate thickness is 120 μm or 150 μm. Regardless of this, it was found that good results were obtained.

  The reason why an organic EL element having a small area of light emission and less emission unevenness was obtained is that, for example, a functional layer such as a light emitting layer was formed on a substrate with a uniform and uniform thickness. It is thought that. That is, it is considered that the area of the portion that does not emit light is reduced because the functional layer is formed with high accuracy. In addition, since the functional layer is formed with a uniform film thickness, it is considered that light emission unevenness is reduced.

  These are considered to be the results obtained because the tension at the time of processing such as functional layer formation (the tension at the time of processing) was raised to a predetermined range. That is, by increasing the processing tension to within a predetermined range, sagging and bending of the base material 50 are eliminated, and thereby the base material 50 is in a state close to a flat surface. And it is thought that the functional layer was formed accurately and uniformly by forming the functional layer on the substrate 50 having such a high flatness. That is, it is considered that the functional layer is accurately formed in a desired form. Thereby, an organic EL element with good performance is obtained.

20 Stepped roll (conveying roll)
30 flat roll (conveying roll)
50 Base material 51 Protective film 52 Organic EL sheet

Claims (3)

An organic process is carried out in a manufacturing apparatus comprising a plurality of transport rolls including stepped rolls that are capable of transporting the belt-like base material in a state where convex parts are formed in the rotation direction and the flexible belt-like base material is in contact with the convex parts. A method for producing an electroluminescent device, comprising:
Under vacuum, the first tension was applied to the band-shaped substrate in the conveying direction of the band-shaped substrate, and the belt-shaped substrate was conveyed while contacting at least the stepped roll, and the first tension was applied. In a state, a base material transport process for transporting the belt-shaped base material to a predetermined position;
After the belt-shaped base material is transported to the predetermined position and the transport of the belt-shaped base material is stopped , the tension applied to the belt-shaped base material is stopped in a state where the transport of the belt-shaped base material is stopped. A tension increasing step of changing to a second tension having a magnitude of 1.5 to 2.5 times the first tension;
The base material that stops the transport of the belt-like base material and performs the processing on the belt-like base material in a state where the second tension having a magnitude different from the first tension is applied to the belt-like base material. A method for producing an organic electroluminescence device, comprising: a treatment step.   2. The method of manufacturing an organic electroluminescence element according to claim 1, wherein at least one of the tension increasing step and the base material treatment step is performed under a vacuum condition. The substrate processing step is performed in a vacuum,
The method for producing an organic electroluminescence element according to claim 1, wherein the treatment in the substrate treatment step is at least one of surface modification of the belt-like substrate and formation of a functional layer.

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