JP2011134627A - Method for manufacturing organic light-emitting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing an organic light-emitting device that can remove a protective film without causing peel-off in a region boundary for protective film removal and can maintain the display performance and the high-quality of an organic light-emitting device over a long period of time without deteriorating a moisture-proof property of the protective film. <P>SOLUTION: The method is used for manufacturing the organic light-emitting device with a structure that is electrically connected to an external circuit 13 by exposing an external connection terminal 9 from the protective film 10. The method sequentially includes: a removing step of removing the protective film 10 that is formed on the external connection terminal 9 by using the difference of a water absorption rate between the protective film 10 and an organic compound layer 7b; a mounting step of electrically connecting the external connection terminal 9 with an external circuit 13; and a forming step of forming a cover layer 15 covering the region boundary for the protective film removal. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for manufacturing an organic light emitting device having a structure in which a protective film formed on an external connection terminal is removed, and the external connection terminal is exposed to be electrically connected to an external circuit.

  In recent years, organic light-emitting devices, which are self-luminous devices, have attracted attention as flat panel displays, and their development has been actively conducted.

  In addition, in order to make use of the light emission characteristics of an organic light emitting device, a technique relating to a protective film has been studied. Here, the protective film is covered over a wide area above and around the organic light emitting element which is a main component of the organic light emitting device, and has a function of blocking moisture and oxygen from the outside.

  When this organic light emitting device is electrically connected to an external circuit such as a flexible printed circuit board (hereinafter referred to as “FPC”), an anisotropic conductive film (hereinafter referred to as “ACF”) is usually used. Specifically, an ACF is sandwiched between an external connection terminal provided in the organic light emitting device and a plurality of terminal electrodes provided in an FPC or the like, and these are electrically connected by thermocompression bonding.

  When performing such electrical connection, normally, when a protective film is formed by plasma CVD or the like so that the protective film is not formed on the external connection terminal, the external connection terminal is covered with a metal mask or the like to form a protective film. A method for preventing the formation is employed. In particular, when manufacturing a large number of organic light emitting devices from a large-sized substrate, it is possible to reduce the cost and time by forming a protective film on the entire surface of the large-sized substrate, so that a protective film is not formed on the external connection terminals. Is particularly important.

  As a method for preventing the formation of the protective film on the external connection terminal, for example, a method of removing the protective film together with the tape by attaching a masking tape on the external connection terminal, forming the protective film and then removing the masking tape Has been proposed (see Patent Document 1).

  In addition, a method has been proposed in which a laser removal layer is formed in a region including an external connection terminal, a protective film is formed thereon, and then the protective film is removed together with the laser removal layer by irradiating a laser (Patent Document 2). reference).

JP 2002-151254 A JP 2004-165068 A

  By the way, in the method of peeling a protective film using a masking tape as in Patent Document 1, there is a possibility that a phenomenon occurs in which the protective film around the tape is locally lifted from the substrate. This is because the protective film on the masking tape and the protective film on the periphery of the tape are continuous, and when the masking tape is peeled upward, the protective film on the periphery of the tape is lifted together. is there.

  In addition, as in Patent Document 2, when the method of removing the protective film by laser irradiation to the laser removal layer is used, as a result of the protective film being blown off from the inside by the rapid volume expansion accompanying the vaporization of the laser removal layer, Similarly, film floating may occur in the protective film on the outer periphery of the laser removal layer. When film floating occurs, when exposed to a severe heat cycle environment that repeats high and low temperatures, peeling of the protective film proceeds from the film floating point due to the difference in thermal expansion coefficient between the protective film and the element substrate, It becomes impossible to maintain high-quality display performance due to a decrease in moisture resistance.

  However, neither of Patent Documents 1 and 2 discloses any treatment for ensuring the moisture resistance of the protective film at the boundary of the protective film removal region.

  The present invention relates to an organic light emitting device having a protective film covering an external connection terminal and having the structure in which the external connection terminal is exposed from the protective film and electrically connected to an external circuit. It is an object of the present invention to provide a method for manufacturing an organic light emitting device capable of preventing deterioration and maintaining the display performance of the organic light emitting device with high quality over a long period of time.

  The configuration of the present invention made to achieve the above object is as follows.

That is, a first manufacturing method according to the present invention includes a substrate including an external connection terminal, an organic light emitting element provided on the substrate, and a protective film covering the external connection terminal and the organic light emitting element, A method of manufacturing an organic light emitting device having a structure in which the external connection terminal is exposed from the protective film and electrically connected to an external circuit,
Removing the protective film for removing the protective film provided on the external connection terminal;
A mounting step of electrically connecting the external connection terminal and the external circuit;
Forming a cover layer covering the protective film removal region boundary, and
Are included in this order.

Further, a second manufacturing method according to the present invention includes a substrate provided with an external connection terminal, an organic light emitting device provided on the substrate, and a protective film covering the external connection terminal and the organic light emitting device, A method of manufacturing an organic light emitting device having a structure in which the external connection terminal is exposed from the protective film and electrically connected to an external circuit,
Removing the protective film for removing the protective film provided on the external connection terminal;
Forming an anisotropic conductive film so as to cover the protective film removal region boundary and the external connection terminal; and
A mounting step of electrically connecting the external connection terminal and the external circuit via the anisotropic conductive film;
Are included in this order.

  According to the present invention, in an organic light emitting device that includes a protective film that covers an external connection terminal and that has an external connection terminal exposed from the protective film and that is electrically connected to an external circuit, the protective film at the boundary of the protective film removal region It is possible to prevent a decrease in moisture resistance and to achieve an excellent effect that the display performance of the organic light emitting device can be maintained at high quality over a long period of time.

It is a schematic sectional drawing which shows the manufacturing method of the organic light-emitting device of 1st Embodiment. It is a schematic plan view which shows the manufacturing method of the organic light-emitting device of 1st Embodiment. In the manufacturing method of 1st Embodiment, it is a plane schematic diagram which shows the scribe line position divided | segmented for every apparatus from a large format board | substrate. It is a cross-sectional schematic diagram in the A-A 'line of FIG. It is a section schematic diagram showing the 2nd manufacturing method of the present invention. It is a plane schematic diagram showing the second manufacturing method of the present invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to the embodiments.

[First Embodiment]
The first manufacturing method according to the present invention includes the following steps (1) to (4) in this order.
(1) A step of forming an organic light emitting device and a protective layer on a substrate provided with external connection terminals (an organic light emitting device and a protective layer forming step).
(2) Step of removing the protective film on the external connection terminal (Step of removing the protective film)
(3) Step of electrically connecting the external connection terminal exposed by removing the protective film and the external circuit (mounting step)
(4) Step of forming a cover layer that covers the protective film removal region boundary (cover layer forming step)

  Hereinafter, with reference to FIG. 1 to FIG. 4, each step of the manufacturing method of the organic light emitting device of the first embodiment will be specifically described. FIG. 1 is a schematic cross-sectional view illustrating the method for manufacturing the organic light-emitting device of the first embodiment. FIG. 2 is a schematic plan view showing the method for manufacturing the organic light-emitting device of the first embodiment. In these drawings, 1 is a substrate, 2 is a TFT circuit, 3 is an insulating layer, 4 is a planarization layer, 5 is a lower electrode, 6 is a bank, 7a and 7b are organic compound layers, 8 is an upper electrode, and 9 is external Connection terminals 10 are protective films. Further, 11 is a brush roller, 12 is an ACF, 13 is an FPC, 14 is a protective resin, 15 is a cover layer, and 16 is a thermocompression bonding head. 1 and 2 show the steps from the organic light emitting element and protective film formation step in the step (1) to the cover layer formation step in the step (4).

  An organic light-emitting device manufactured by the manufacturing method according to the present invention includes a substrate 1 provided with external connection terminals 9, an organic light-emitting element provided on the substrate 1, a protective film 10 covering the organic light-emitting element, and an external connection terminal 9 And an external circuit such as an FPC 13 that is electrically connected to the organic light-emitting element via the.

<Formation process of organic light emitting device>
First, with reference to FIG. 1 (1) and FIG. 2 (1), the process of forming an organic light emitting element on the board | substrate provided with the external connection terminal is demonstrated. As shown in FIG. 1A, a TFT circuit 2 is formed on a substrate 1 of the organic light emitting device.

  Examples of the substrate 1 include, but are not limited to, an insulating substrate made of a glass substrate, a synthetic resin, or the like, a conductive substrate or a semiconductor substrate on which an insulating layer such as silicon oxide or silicon nitride is formed on the surface, and the like. The substrate 1 may be transparent or opaque.

  As shown in FIG. 1A, a planarizing film 4 made of, for example, an acrylic resin, a polyimide resin, a norbornene resin, a fluorine resin, or the like is formed on the substrate 1 including the TFT circuit 2 by a photolithography method or the like. It is formed in a desired pattern. Here, the flattening layer 4 is a layer for flattening unevenness caused by providing the TFT circuit 2. The material and manufacturing method of the planarizing layer 4 are not particularly limited as long as the unevenness due to the installation of the TFT circuit 2 can be planarized. As shown in FIG. 1A, an insulating layer 3 made of an inorganic material such as silicon nitride, silicon oxynitride, or silicon oxide may be formed between the planarization film 4 and the TFT circuit 2. Good.

  The lower electrode 5 provided on the planarizing layer 4 and electrically connected to a part of the TFT circuit 2 may be a transparent electrode or a reflective electrode. Examples of the constituent material in the case where the lower electrode 5 is a transparent electrode include ITO (indium oxide-tin oxide), IZO (indium oxide-zinc oxide), and the like. As the constituent material when the lower electrode 5 is a reflective electrode, for example, a single metal such as Au, Ag, Al, Pt, Cr, Pd, Se or Ir, an alloy obtained by combining a plurality of these single metals, or copper iodide And the like, and the like. The thickness of the lower electrode 5 is preferably in the range of 0.1 μm to 1 μm, but is not limited to this range.

  As shown in FIG. 1 (1), a bank 6 is provided on the peripheral edge of the lower electrode 5. Examples of the constituent material of the bank 6 include an inorganic insulating layer made of silicon nitride, silicon oxynitride, silicon oxide or the like, an acrylic resin, a polyimide resin, or a novolac resin. The film thickness of the bank 6 is preferably in the range of 1 μm to 5 μm, but is not limited to this range.

  Next, as shown in FIG. 1A, an organic compound layer 7 a is provided on the lower electrode 5. The organic compound layer 7a may be composed of a single layer or a plurality of layers, and can be appropriately selected in consideration of the light emitting function of the organic light emitting element. Specifically, examples of the layer constituting the organic compound layer 7a include a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, and an electron injection layer. Moreover, a well-known compound can be used as a constituent material of these layers. The organic compound layer 7a may have a light emitting region in a specific layer or an interface between adjacent layers. The organic compound layer 7a is formed by, for example, a vacuum deposition method, an inkjet method, or the like. In the case of vapor deposition or the like, an organic compound layer is formed in the light-emitting area using a high-definition mask, and in the case of an inkjet method or the like, high-precision discharge is used.

  As shown in FIGS. 1 (1) and 2 (1), it is desirable to provide an organic compound layer 7b on the external connection terminal 9 as well. A material equivalent to that of the organic compound layer 7a can be used for the organic compound layer 7b. By providing the organic compound layer 7b on the external connection terminal 9, the protective film 10 is removed when the protective film 10 is removed by utilizing the difference in water absorption between the protective film 10 and the organic compound layer 7b as described later. 10 can be easily removed from the external connection terminals 9, the process time can be shortened, and defective electrical connection can be reduced.

  Then, as shown in FIG. 1A, an organic light emitting element is formed on the substrate 1 by forming the upper electrode 8 on the organic compound layer 7a. When light emission is extracted from the upper electrode 8 side, the upper electrode 8 is preferably transparent, and for example, the transparent electrode such as ITO or IZO can be used. Moreover, when using metal electrodes, such as Ag, Au, Al, as the upper electrode 8, from a viewpoint of the light transmittance of a metal electrode, it is preferable that it is 50 nm or less, and it is more preferable that it is 20 nm or less. One external connection terminal 9 present for each organic light emitting element is formed simultaneously with the lower electrode 5 when the lower electrode 5 is formed.

<Protective film formation process>
Next, with reference to FIG. 1A and FIG. 2A, a process of forming the protective film 10 will be described. As shown in FIG. 1A and FIG. 2A, a protective film 10 is formed so as to cover the entire surface of the organic light emitting element and the external connection terminal 9 formed on the substrate 1. The constituent material of the protective film 10 is not particularly limited as long as it is a material that has electrical insulation and airtightness and can prevent deterioration of the organic light emitting element, but water absorption between the protective film 10 and the organic compound layer 7b. When the protective film 10 is removed using the difference in rate, a material having a difference in water absorption from the organic compound is preferable. Specific examples include inorganic materials such as silicon nitride, silicon oxide, and silicon nitride oxide. In addition, as a method for forming the protective film 10, for example, a vacuum deposition method, a plasma CVD method, a sputtering method, or the like can be adopted, but the plasma CVD method is preferable in consideration of a film formation speed and coverage with respect to particles. In addition, as the protective film 10, it is preferable to use a film that has been confirmed to have no intrusion of moisture or the like in a durability test under a high temperature and high humidity condition (for example, a temperature of 60 ° C. and a humidity of 90%).

<Large-size substrate cutting and dividing process>
Usually, an organic light-emitting device having a single organic light-emitting element is not manufactured on the substrate 1, but a large-sized substrate in which a plurality of organic light-emitting elements are arranged in a matrix is manufactured, and then the large-sized substrate 21 is used as a scriber. And divide every device.

  FIG. 3 is a schematic plan view showing a scribe line when cutting the substrate. FIG. 4 is a schematic cross-sectional view taken along the line A-A ′ of FIG. 3. 3 and 4, reference numeral 21 denotes a large substrate, and 30 denotes a scribe line.

  As shown in FIGS. 3 and 4, if the large substrate 21 is cut along the scribe line 30, the cross section of the organic compound layer 7 b formed on the external connection terminal 9 is exposed, and the protective film removing step is performed with the protective film 10. In the step of removing the protective film 10 using the difference in water absorption with the organic compound layer 7b, the organic compound layer 7b and the protective film 10 can be easily peeled off from the external connection terminal 9.

<Protection film removal process>
Next, with reference to FIG. 1 (2) and FIG. 2 (2), the removal process of the protective film 10 of the said process (2) is demonstrated. As shown in FIG. 1 (2), one apparatus obtained by cutting and dividing from a large substrate 21 is brushed using a brush roller 11 or the like while applying pure water or an aqueous solution. The exposed organic compound layer 7b is exposed to pure water or an aqueous solution and brushed at a desired pressure, so that the protective film 10 provided on the external connection terminal 9 is peeled off from the interface with the organic compound layer 7b. To do. Examples of the aqueous solution used include ozone water, organic alkali cleaning liquid, dilute hydrofluoric acid (DHF), and surfactant-added aqueous solution.

The reason why the protective film 10 peels from the organic compound layer 7b by being brought into contact with pure water or an aqueous solution is due to the difference in water absorption between the protective film 10 made of an inorganic material and the organic compound layer 7b. The inorganic material constituting the protective film 10 has a water absorption rate of approximately 0%, while the organic compound layer 7b has a water absorption rate of 10 ⁻¹ % to several%. For this reason, by bringing the cut exposed portion into contact with pure water or an aqueous solution, only the organic compound layer 7b expands, so that the protective film 10 provided on the organic compound layer 7b is peeled off. Further, since the organic compound layer 7b is formed by a vapor deposition method, the adhesion to the external connection terminal 9 is low, and it can be easily peeled off from the external connection terminal 9 by brushing. In this way, neither the protective film 10 nor the organic compound layer 7b is formed on the external connection terminal 9.

  The method for removing the protective film is not limited to the method for removing the protective film using the difference in water absorption between the protective film and the organic compound layer as described above. For example, a method of peeling using a masking tape described in Patent Document 1 or a method of peeling with a laser for each laser removal layer described in Patent Document 2 may be used.

<Mounting process>
Next, with reference to FIG. 1 (3) and FIG. 2 (3), the mounting process of the said process (3) is demonstrated. In performing this step, first, the external connection terminal 9 of the organic light emitting device is washed with a nonwoven paper or the like soaked with a solvent such as isopropyl alcohol (IPA). When the organic compound layer 7b remains on the external connection terminal 9, the residue can be removed by washing with a non-woven paper soaked with IPA, and the external connection terminal 9 can be exposed.

  Subsequently, the anisotropic conductive film (ACF) 12 is temporarily pressure-bonded on the external connection terminal 9, and the flexible printed wiring board (FPC) 13 and the external connection terminal 9 are aligned. When performing temporary pressure bonding, it is preferable to perform pressure bonding at a low temperature of 100 ° C. or lower.

  The ACF 12 to be used may be one in which the conductive particles contained in the film contain a metal powder, or may be a resin coated with a metal. Further, carbon or the like that is inexpensive and hardly deteriorates may be used as the conductive particles. Although the diameter of the conductive particles depends on the thickness of the organic compound layer, generally, the diameter is 10 nm or less.

  After performing the temporary pressure bonding, the heat pressure bonding head 16 performs heat pressure bonding. Note that the pressure, temperature, and time required for thermocompression bonding are not particularly limited as long as electrical connection between the external connection terminal 9 and the electrode terminal of the FPC 13 can be secured.

  Normally, after the external connection terminal 9 and the electrode terminal of the FPC 13 are electrically connected, the protective resin 14 is applied to the connection portion. As the protective resin 14, silicon resin or the like is generally used, and functions to prevent moisture from entering the connecting portion and suppress the occurrence of ion migration. Further, when the adhesive strength is not strong with only the ACF 12, it is preferable to apply the protective resin 14 from the viewpoint of reinforcing the adhesive strength. As a method for forming the protective resin 14, for example, various printing methods can be used. However, since there is a large step between the FPC 13 and the substrate, a dispensing method is preferable.

<Cover layer formation process>
Next, with reference to FIG. 1 (4) and FIG. 2 (4), the formation process of the cover layer 15 of the said process (4) is demonstrated.

  As shown in FIGS. 1 (4) and 2 (4), a cover layer 15 is formed so as to cover the protective film removal region boundary. As a method for forming the cover layer 15, the dispensing method is suitable for the same reason as described for the protective resin 14. As a material for the cover layer 15, any resin can be used as long as it has good adhesion to the substrate 1. Specifically, a silicon resin, an epoxy resin, an acrylic resin, a polyimide resin, a urethane resin, Polyamide resin etc. are mentioned. In particular, silicon resin and epoxy resin are preferable because of their high sealing performance. The thickness of the cover layer 15 is, for example, about 5 μm to 50 μm, and an effect of sufficiently suppressing the peeling of the protective film 10 is obtained. Note that it is preferable to use a material equivalent to the above-described protective resin 14 as the cover layer 15 because the cover layer 15 can be formed at the same time when the protective resin 14 is formed. In that case, it is not necessary to separate the formation region of the protective resin 14 and the formation region of the cover layer 15 and can be formed in one continuous region.

  An organic light emitting device is manufactured through the above manufacturing steps. According to the manufacturing method of the first embodiment, when the protective film 10 on the external connection terminal 9 is removed and the external connection terminal 9 is exposed to be electrically connected to an external circuit, the protective film 10 that is an inorganic material and the organic film The protective film 10 is removed together with the organic compound layer 7b by utilizing the difference in water absorption with the compound layer 7b. That is, the organic compound layer 7b on the external connection terminal 9 is hydrated, and the protective film 10 is mechanically removed together with the organic compound layer 7b. Accordingly, when the protective film 10 is removed, the protective film removal region boundary is hardly peeled off, and the protective film removal region boundary is covered with the cover layer, so that the moisture resistance of the protective film 10 is not deteriorated and the organic light emitting device The display performance can be maintained with high quality over a long period of time.

[Second Embodiment]
The second manufacturing method according to the present invention includes the following steps (1) to (4) in this order.
(1) A step of forming an organic light emitting device and a protective layer on a substrate provided with external connection terminals (an organic light emitting device and a protective layer forming step).
(2) Step of removing the protective film on the external connection terminal (Step of removing the protective film)
(3) Step of forming an anisotropic conductive film (ACF) so as to cover the protective film removal region boundary and the external connection terminal (ACF forming step)
(4) Step of electrically connecting the external connection terminal and the external circuit (FPC) via the ACF (mounting step)

  Hereinafter, with reference to FIG.5 and FIG.6, each process of the manufacturing method of the organic light-emitting device of 2nd Embodiment is demonstrated concretely. FIG. 5 is a schematic cross-sectional view illustrating the method for manufacturing the organic light emitting device of the second embodiment. FIG. 6 is a schematic plan view showing a method for manufacturing the organic light emitting device of the second embodiment. In these drawings, the same members as those of the first embodiment are denoted by the same reference numerals, and the description of the same manufacturing method as that of the first embodiment will be omitted as appropriate. 5 and 6 show the steps from the organic light emitting element and protective film forming step in the step (1) to the mounting step in the step (4).

  As described above, the organic light emitting device includes the substrate 1 including the external connection terminal 9, the organic light emitting element provided on the substrate 1, the protective film 10 covering the organic light emitting element, and the organic light emission via the external connection terminal 9. And an external circuit such as an FPC 13 that is electrically connected to the element.

<Formation process of organic light emitting device>
In the second embodiment, as shown in FIGS. 5 (1) and 6 (1), the organic light emitting element and the external connection terminal 9 are formed on the substrate 1 by the same manufacturing method as in the first embodiment. .

<Protective film formation process, large-size substrate cutting and dividing process>
After the protective film 10 is formed on the entire surface by the same manufacturing method as in the first embodiment, the large-sized substrate 21 is cut by the scriber line 6 by the same method as in the first embodiment and divided for each apparatus. By this division, the cross section of the organic compound layer 7b formed on the external connection terminal 9 is exposed.

<Protection film removal process>
Next, as shown in FIGS. 5 (2) and 6 (2), the protective film 10 on the external connection terminal 9 is peeled off together with the organic compound layer 7b by the process of removing the protective film 10 in the step (2). . In this step, the same manufacturing method as in the first embodiment can be used.

<Formation process of anisotropic conductive film>
Next, with reference to FIG. 5 (3) and FIG. 6 (3), the formation process of the anisotropic conductive film (ACF) 12 of the said process (3) is demonstrated. First, after cleaning the external connection terminals 9 with a nonwoven paper or the like soaked with a solvent such as isopropyl alcohol (IPA), as shown in FIGS. 5 (3) and 6 (3), the protective film removal region The ACF 12 is temporarily crimped so as to completely cover the boundary portion and the external connection terminal 9. In this manner, the ACF 12 is formed so as to completely cover not only the external connection terminal 9 but also the boundary of the protective film removal region, so that the protective film can be removed without adding a separate step of forming the cover layer 15. The protective film 10 at the region boundary can be protected. In addition, when performing temporary pressure bonding, it is preferable to perform pressure bonding at a low temperature of 100 ° C. or lower. As the conductive particles contained in the ACF 12, the same particles as those described in the first embodiment can be used.

<Mounting process>
Next, as shown in FIGS. 5 (4) and 6 (4), in the mounting step (4), the external connection terminal 9 and the FPC 13 are electrically connected. The specific manufacturing method is the same as that of the first embodiment.

  An organic light emitting device is manufactured through the above manufacturing steps. The manufacturing method of the second embodiment has basically the same effects as the manufacturing method of the first embodiment. In particular, in the manufacturing method according to the second embodiment, the ACF 12 is formed so as to cover not only the external connection terminal 9 but also the boundary of the protective film removal region in the manufacturing method of the second embodiment. is doing. Therefore, the manufacturing method of the second embodiment can protect the protective film 10 at the boundary of the protective film removal region by expanding the ACF 12 used for thermocompression bonding, and can omit the step of forming the cover layer 15. There is a unique effect.

  The preferred embodiment of the present invention has been described above. However, this is merely an example for explaining the present invention, and various embodiments different from the above-described embodiment may be implemented without departing from the gist of the present invention. Can do.

  For example, in the above embodiment, an active organic light emitting device is illustrated as an example, but a passive organic light emitting device may be used. In the organic light emitting device manufactured in this embodiment, the external connection terminals 9 are provided only on one side, but the external connection terminals 9 may be provided at a plurality of locations on two or more sides.

  EXAMPLES Hereinafter, although an Example is given and the manufacturing method of the organic light-emitting device concerning this invention is demonstrated further in detail, this invention is not limited to these Examples.

[Example 1]
In Example 1, an organic light-emitting device was manufactured using the first manufacturing method according to the present invention, and each step will be described in detail below.

<TFT array substrate fabrication process>
A flat film made of a positive photosensitive acrylic resin is formed on a TFT substrate formed by an LTPS (low-temperature poly-Si TFT) process to a thickness of about 2 μm, and then this TFT substrate is heated to 220 ° C. for heat treatment. Went.

  Next, UV exposure, development processing, and heating UV processing are sequentially performed using a photomask for forming a desired pattern in a portion corresponding to a contact hole and an external connection terminal for electrically connecting the TFT and a lower electrode to be described later. Went to. By these treatments, a flattened film on which a desired pattern was formed was obtained. At this time, a strip-shaped portion without a planarizing film was provided between the display portion (a portion where an organic light-emitting element to be described later is formed) and the outer peripheral portion so that the wiring of the TFT substrate was exposed. The portion where the wiring of the TFT substrate is exposed forms a moisture blocking structure, and has a role of preventing moisture from entering the display portion from the outer peripheral portion through the planarization film.

  Next, Al and IZO were sequentially stacked by sputtering to form a lower electrode and an external connection terminal, respectively. At this time, the film thicknesses of Al and IZO were 200 nm and 50 nm, respectively. Next, a bank made of a positive polyimide resin (trade name: Photonice DL-1000) was formed in a desired pattern around a portion where a pixel was to be formed by a photolithography process. At this time, the bank thickness was 2 μm. A TFT array substrate was produced as described above.

<Formation process of organic light emitting device>
Next, a hole transport layer, a light emitting layer, an electron transport layer, and an electron injection layer constituting the organic compound layer were formed in this order by a vacuum deposition method. Specifically, first, αNPD was formed on the lower electrode and the external connection terminal to form a hole transport layer. At this time, the thickness of the hole transport layer was 50 nm.

Next, an aluminum chelate complex (Alq ₃ ) as a host and coumarin 6 as a guest are co-evaporated to a weight ratio of 100: 6 on the hole transport layer of the lower electrode to form a light emitting layer. did. At this time, the thickness of the light emitting layer was set to 50 nm.

Next, a phenanthroline compound (Bphen) was formed on the light emitting layer to form an electron transport layer. At this time, the thickness of the electron transport layer was 10 nm. Next, on the electron transport layer, a phenanthroline compound (Bphen) and cesium carbonate (Cs ₂ CO ₃ ) were co-evaporated to a weight ratio of 100: 1 to form an electron injection layer. At this time, the thickness of the electron injection layer was set to 30 nm.

  Next, an IZO film was formed on the electron injection layer by sputtering to form an upper electrode. At this time, the film thickness of the upper electrode was 100 nm. As described above, an organic light emitting device was produced.

<Protective film formation process>
After the formation of the upper electrode, the large substrate was moved to the CVD chamber, and a protective film was formed on the entire large substrate by plasma CVD. When forming the protective film, SiH ₄ gas and N ₂ gas were used as material gases and flowed at a flow rate of 4 sccm and 200 sccm, respectively. The protective film was formed under the conditions of high frequency power 40 W and pressure 70 Pa. At this time, the thickness of the protective film was 3 μm. After forming the protective film, move the large format substrate from the deposition system to the front chamber, start venting (release the vacuum), open the chamber lid after venting is completed, and remove the substrate on which the protective film is formed. Took out.

<Substrate cutting and dividing process and protective film removing process>
Next, the large format substrate in which the organic light emitting devices were formed in a matrix was cut with a scriber for each device. After cutting, each device was subjected to brush spin cleaning with hot water at 50 ° C. (holding rotation speed 3000 rpm, holding time 45 seconds) to remove the protective film.

<External circuit mounting process>
Next, the FPC necessary for electrically connecting the driving circuit for driving the organic light emitting device and the external circuit was mounted. First, the surface of the external connection terminal was cleaned by washing the external connection terminal on the substrate with a nonwoven fabric containing IPA.

  Next, after ACF is temporarily pressure-bonded on the external connection terminal at 80 ° C. for about 1 second, the protective sheet on the ACF is removed, and alignment between the substrate alignment mark and the FPC alignment mark of the FPC is performed. It was. After the mark position was matched, it was set under the thermocompression bonding head, the heater head was heated to the melting temperature of ACF (250 ° C.), and the compression was completed in a pressure bonding pressure of 3 MPa and a pressure bonding time of 12 seconds.

<Process for forming protective resin and cover layer>
Next, a protective resin was formed at the joint between the external connection terminal of the organic light emitting device and the FPC, and the FPC end face was completely covered. Further, a cover layer was formed so as to completely cover the protective film removal region boundary. Both the protective resin and the cover layer were formed by applying a one-part room temperature curable silicone resin (Dow Corning (registered trademark) JSR6224) simultaneously by a dispenser. The thickness of the cover layer was 50 μm, and the thickness of the protective resin was 300 μm. Ten organic light-emitting devices were produced by the above process.

<Evaluation of organic light emitting device>
About the organic light-emitting device produced in Example 1, after repeating a heat cycle (-35 degreeC-80 degreeC) 100 times, the endurance test was implemented for 1000 hours on the conditions of temperature 80 degreeC humidity 90%. As a result of confirming the presence or absence of display defects by lighting up 10 organic light emitting devices after the test, the generation and progression of display defects from the boundary of the protective film removal region are not seen, and the display quality can be maintained. It was confirmed.

[Example 2]
In Example 2, an organic light-emitting device was manufactured using the second manufacturing method according to the present invention, and each step will be described in detail below.

<From TFT array substrate fabrication process to substrate cutting and protective film removal process>
The TFT array substrate preparation process, the organic light emitting device preparation, the protective film formation and substrate removal process, the substrate cutting and the protective film removal process were performed in this order in the same manner as in Example 1.

<ACF formation process>
Next, the ACF was formed so as to completely cover the protective film at the boundary between the external connection terminal and the protective film removal region, and was temporarily pressure-bonded at a temperature of 80 ° C. for 1 second. Thereafter, the ACF protective film was peeled off. The ACF used was the same as in Example 1.

<External circuit mounting process>
In the same manner as in Example 1, an external circuit mounting process was performed. Ten organic light-emitting devices were produced by the above process.

<Evaluation of organic light emitting device>
About the organic light-emitting device produced in Example 2, after repeating a heat cycle (-35 degreeC-80 degreeC) 100 times similarly to Example 1, a 1000-hour endurance test is carried out on the conditions of temperature 80 degreeC and humidity 90%. Carried out. As a result of confirming the presence or absence of display defects by lighting up 10 organic light emitting devices after the test, the generation and progression of display defects from the boundary of the protective film removal region are not seen, and the display quality can be maintained. It was confirmed.

[Comparative Example]
Up to mounting was performed by the method described in Example 1 above, and 10 organic light emitting devices in which the cover layer was not formed at the boundary portion of the protective film removal region were produced.

  The heat cycle (-35 ° C. to 80 ° C.) was repeated 100 times in the same manner as in Example 1, and then a 1000 hour durability test was performed under the conditions of a temperature of 80 ° C. and a humidity of 90%. As a result of confirming the occurrence of display defects by lighting 10 organic light emitting devices after the test, the progress of display defects (non-display areas) was confirmed only from the side where the protective film removal region was present in all 10 groups. Observation with an optical microscope without turning on the organic light emitting device confirmed that the film peeling of the protective film extends from the boundary of the protective film removal region to the display area.

  From the above results, by using the manufacturing method of the present invention, it is possible to prevent a decrease in moisture resistance of the protective film at the boundary of the protective film removal region in a harsh environment, and to maintain a high quality display quality for a long period of time. understood.

DESCRIPTION OF SYMBOLS 1 Board | substrate, 5 Lower electrode, 7a Organic compound layer, 7b Organic compound layer, 8 Upper electrode, 9 External connection terminal, 10 Protective film, 12 Anisotropic conductive film (ACF), 13 Flexible printed circuit board (FPC), 15 Cover layer , 21 Large format board

Claims (5)

A substrate including an external connection terminal; an organic light-emitting element provided on the substrate; and a protective film covering the external connection terminal and the organic light-emitting element. The external connection terminal is exposed from the protective film and externally provided. A method of manufacturing an organic light emitting device having a structure that is electrically connected to a circuit,
A protective film removing step for removing the protective film provided on the external connection terminal;
A mounting step of electrically connecting the external connection terminal and the external circuit;
Forming a cover layer covering the protective film removal region boundary, and
The organic light-emitting device manufacturing method characterized by including this in this order.   The protective film is an inorganic material, and the protective film removing step removes the protective film provided on the external connection terminal using a difference in water absorption between the protective film and the organic compound layer. The method of manufacturing an organic light-emitting device according to claim 1, wherein   The method for manufacturing an organic light-emitting device according to claim 1, wherein the cover layer is one of silicon resin and epoxy resin. A substrate including an external connection terminal; an organic light-emitting element provided on the substrate; and a protective film covering the external connection terminal and the organic light-emitting element. The external connection terminal is exposed from the protective film and externally provided. A method of manufacturing an organic light emitting device having a structure that is electrically connected to a circuit,
A protective film removing step for removing the protective film provided on the external connection terminal;
Forming an anisotropic conductive film so as to cover the protective film removal region boundary and the external connection terminal; and
A mounting step of electrically connecting the external connection terminal and the external circuit via the anisotropic conductive film;
The organic light-emitting device manufacturing method characterized by including this in this order.   The protective film is an inorganic material, and the protective film removing step removes the protective film provided on the external connection terminal using a difference in water absorption between the protective film and the organic compound layer. The method of manufacturing an organic light emitting device according to claim 4, wherein

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