Manufacturing method for organic EL elements

Abstract

The present invention provides a method for manufacturing an organic EL element that prevents the sealing resin from adhering to the electrode region. [Solution] A method for manufacturing an organic EL element comprising a first substrate 3 having a display area 5 on which a light-emitting layer is formed and an electrode area 6 on which electrode terminals are formed, and a transparent second substrate 4, with a sealing resin 8 interposed between them so as to cover the display area 5, wherein the method for manufacturing an organic EL element includes a protective film formation step of forming a protective film 7 on the electrode area 6 before covering the display area 5 with the sealing resin 8.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing an organic electroluminescence device (hereinafter referred to as an organic EL device).

Background Art

[0002] FIG. 8 is a (a) top view and (b) cross-sectional view taken along A-A' showing a part of the manufacturing process of an organic EL device in the prior art. FIG. 9 is a cross-sectional view showing an organic EL device manufactured by the manufacturing method of an organic EL device in the prior art. In the prior art, the organic EL device 2 shown in FIG. 9 is formed, for example, as shown in FIG. 8, by dividing a mother substrate 1 formed by bonding a first substrate 3 provided with a display region 5 in which a light-emitting layer made of an organic material is formed and an electrode region 6 in which electrode terminals are formed, and a transparent second substrate 4 through a transparent sealing resin 8 into individual pieces.

[0003] The light-emitting layer of the organic EL device 2 is likely to deteriorate due to moisture and oxygen in the air. To prevent this, the sealing resin 8 is filled so as to cover the display region 5 of the organic EL device 2, and the second substrate 4 is bonded to the first substrate 3 through this sealing resin 8. The sealing resin 8 is generally mainly an ultraviolet curable resin or a thermosetting resin.

[0004] <{ In the manufacturing method of the organic EL device 2, from the viewpoint of production efficiency, it is often the case that a plurality of organic EL devices 2 are manufactured from a single large substrate. For example, in FIG. 8, four organic EL devices 2 are formed on a single first substrate 3, and the first substrate 3 and the second substrate 4 are bonded through the sealing resin 8 applied to the display region 5 to form a mother substrate 1. After curing the sealing resin 8, the mother substrate 1 is divided into individual pieces to form four individual organic EL devices 2. At that time, in order to expose the electrode region 6 of the organic EL device 2 to the outside, the second substrate 4 provided above the electrode region 6 is removed. However, if the sealing resin 8 has spread to the electrode region 6, the sealing resin 8 may remain attached to the electrode region 6, and there is a possibility of conduction failure or the like.

[0005] One proposed method for solving these problems involves removing the sealing resin adhering to the electrode region using a laser. (See, for example, Patent Documents 1 and 2.) [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2006-66364 [Patent Document 2] Japanese Patent Publication No. 2006-185593 [Overview of the project] [Problems that the invention aims to solve]

[0007] In methods that remove sealing resin adhering to the electrode area using a laser, there is a possibility that the laser may damage the electrode area, and also that carbides of the sealing resin generated by the laser may adhere to the electrode area.

[0008] This invention has been made in view of the above problems, and aims to provide a method for manufacturing an organic EL element that can prevent the sealing resin from adhering to the electrode region. [Means for solving the problem]

[0009] A method for manufacturing an organic EL element, comprising a first substrate having a display area on which a light-emitting layer is formed and an electrode area on which electrode terminals are formed, and a transparent second substrate, with a sealing resin interposed between the first substrate so as to cover the display area, wherein the method for manufacturing an organic EL element includes a protective film formation step of forming a protective film on the electrode area before covering the display area with the sealing resin.

[0010] The method for manufacturing an organic EL element may also include a sealing resin coating step of applying the sealing resin to the first substrate so as to cover the display area after the protective film forming step, and a substrate bonding step of bonding the first substrate and the second substrate via the sealing resin applied to the first substrate in the sealing resin coating step.

[0011] The sealing resin may be applied to a thickness greater than that of the protective film, which may be a method for manufacturing an organic EL element.

[0012] The method for manufacturing an organic EL element may also include a substrate bonding step in which the protective film is made of an adhesive material and the first substrate and the second substrate are bonded together via the protective film made of the adhesive material, and a sealing resin injection step in which the sealing resin is injected into the gap between the first substrate and the second substrate formed by the substrate bonding step so as to cover the display area.

[0013] The first substrate is provided with a plurality of organic EL element formation regions, the protective film is formed continuously across adjacent formation regions in a predetermined direction, and the sealing resin is injected along the predetermined direction, which may be a method for manufacturing an organic EL element. [Effects of the Invention]

[0014] According to the present invention, it is possible to provide a method for manufacturing an organic EL element that can prevent the sealing resin from adhering to the electrode region. [Brief explanation of the drawing]

[0015] [Figure 1] (a) Top view, (b) Cross-sectional view A-A' showing a part of the manufacturing process (protective film formation process) of the organic EL element in Example 1 of the present invention. [Figure 2] (a) Top view, (b) Cross-sectional view A-A' showing a part of the manufacturing process (encapsulation resin coating process to substrate bonding process) of the organic EL element in Example 1 of the present invention. [Figure 3](a) Top view and (b) cross-sectional view taken along line A-A' showing part of the manufacturing process of the organic EL device (substrate cutting process 1) in Example 1 of the present invention [Figure 4] (a) Top view and (b) cross-sectional view taken along line A-A' showing part of the manufacturing process of the organic EL device (substrate cutting process 2) in Example 1 of the present invention [Figure 5] (a) Top view and (b) cross-sectional view taken along line A-A' showing part of the manufacturing process of the organic EL device (protective film removal process) in Example 1 of the present invention [Figure 6] (a) Top view and (b) cross-sectional view taken along line A-A' showing part of the manufacturing process of the organic EL device (substrate bonding process) in Example 2 of the present invention [Figure 7] Side view showing part of the manufacturing process of the organic EL device (sealing resin injection process) in Example 2 of the present invention [Figure 8] (a) Top view and (b) cross-sectional view taken along line A-A' showing part of the manufacturing process of the organic EL device (substrate bonding process) in the prior art [Figure 9] Cross-sectional view of an organic EL device manufactured by the manufacturing method of an organic EL device in the prior art

Mode for Carrying Out the Invention

[0016] Hereinafter, embodiments (Examples 1 and 2) of the present invention will be described.

Example

[0017] FIG. 1 is a (a) top view and (b) cross-sectional view taken along line A-A' showing a part (protective film forming process) of the manufacturing process of the organic EL element in Example 1 of the present invention. Here, a manufacturing method for manufacturing a plurality of organic EL elements 2 from a single large substrate is shown. In Example 1, first, as shown in FIG. 1, a first substrate 3 (for example, a silicon substrate) provided with a display region 5 in which a light-emitting layer made of an organic material is formed and an electrode region 6 in which electrode terminals are formed is prepared. A protective film 7 made of resin or the like is formed on the first substrate 3 so as to completely cover the electrode region 6 of the first substrate 3, and the protective film 7 is cured as necessary. The protective film 7 is continuously formed from one end portion (the upper end portion in FIG. 1) to the other end portion (the lower end portion in FIG. 1) of the first substrate 3 so as to straddle between two adjacent organic EL elements 2 in the arrangement direction of the electrode terminals formed in the electrode region 6 (the vertical direction in FIG. 1). The protective film 7 is formed, for example, by screen printing, but may be formed by a dispenser, vapor deposition, or the like. The material of the protective film 7 is appropriately selected, but a material that can be easily removed from the first substrate 3 is preferable. The protective film 7 may be composed of an adhesive tape or the like.

[0018] FIG. 2 is a (a) top view and (b) cross-sectional view taken along line A-A' showing a part (sealing resin coating process to substrate bonding process) of the manufacturing process of the organic EL element in Example 1 of the present invention. Next, as shown in FIG. 2, a sealing resin 8 is applied on the first substrate 3 so as to cover the display region 5, and after bonding the first substrate 3 and the second substrate 4 (for example, a glass substrate) through the sealing resin 8, the sealing resin 8 is cured as necessary to create a mother substrate 1. The sealing resin 8 is continuously applied, for example, from one end portion (the upper end portion in FIG. 2) to the other end portion (the lower end portion in FIG. 2) of the first substrate 3. The sealing resin 8 is preferably applied to be thicker than the protective film 7 so as to surely contact the surface of the second substrate 4. The sealing resin 8 is, for example, an ultraviolet curable resin and is applied by screen printing, but may be applied by a dispenser or the like. Even if the applied sealing resin 8 spreads by wetting toward the electrode region 6 side, the electrode region 6 is not contaminated by the sealing resin 8 because it is covered with the protective film 7.

[0019] Figure 3 shows (a) a top view and (b) a cross-sectional view along A-A', which are part of the manufacturing process (substrate division process 1) of an organic EL element in Embodiment 1 of the present invention. Next, as shown in Figure 3, the first substrate 3 and the second substrate 4 are divided along the division line 10 using an arbitrary dicing apparatus, and a number of (in this case, 4) individual organic EL elements 2 are cut out from the mother substrate 1.

[0020] Figure 4 shows (a) a top view and (b) a cross-sectional view along A-A', which are part of the manufacturing process (substrate division process 2) of an organic EL element in Embodiment 1 of the present invention. Next, as shown in Figure 4, the second substrate 4 is divided along the division line 11 using any dicing apparatus, and the second substrate 4 above the electrode region 6 is removed. This exposes the protective film 7 covering the electrode region 6 to the outside.

[0021] Figure 5 shows (a) a top view and (b) a cross-sectional view along A-A', illustrating a part of the manufacturing process (protective film removal process) of an organic EL element in Embodiment 1 of the present invention. Next, as shown in Figure 5, the protective film 7 covering the electrode region 6 is removed. This exposes the electrode region 6 to the outside. If sealing resin 8 is attached to the surface of the protective film 7, the attached sealing resin 8 is removed along with the protective film 7. The means for removing the protective film 7 are appropriately selected depending on the material of the protective film 7, but for example, ashing or solvents can be used. Also, if the protective film 7 is a low-tack adhesive tape or the like, the protective film 7 can be peeled off.

[0022] As described above, in Example 1, the electrode region 6 is covered with the protective film 7 before the sealing resin 8 is applied to the display region 5, thus preventing the sealing resin 8 from adhering to the electrode region 6. [Examples]

[0023] Figure 6 shows (a) a top view and (b) a cross-sectional view along A-A', illustrating a part of the manufacturing process (substrate bonding process) of an organic EL element in Embodiment 2 of the present invention. In Embodiment 2, as shown in Figure 6, a protective film 7 made of adhesive resin is uniformly applied to cover the electrode region 6 of the first substrate 3. The first substrate 3 and the second substrate 4 are then bonded together via the protective film 7, and the protective film 7 is cured as needed to create the mother substrate 1. In this case, a resin mixed with numerous spacers 13 is used as the material for the protective film 7 in order to maintain a constant gap between the first substrate 3 and the second substrate 4. The spacers 13 are spherical members made of, for example, silica. While it is preferable to provide the spacers 13, they are not essential and can be omitted.

[0024] Figure 7 is a side view showing a part of the manufacturing process (encapsulation resin injection process) of an organic EL element in Embodiment 2 of the present invention. Next, encapsulation resin 8 is injected into the gap between the first substrate 3 and the second substrate 4 that constitute the mother substrate 1 using capillary action. Specifically, as shown in Figure 7, the mother substrate 1 is positioned vertically, and the encapsulation resin 8 filled in the holding container 12 is brought into contact with the side surface of the mother substrate 1 located below. The gap (distance) between the first substrate 3 and the second substrate 4 is, for example, a few micrometers or less, so the encapsulation resin 8 is injected into the gap between the first substrate 3 and the second substrate 4 by capillary action. At this time, the encapsulation resin 8 is injected from the bottom to the top of the mother substrate 1 along the protective film 7 that extends vertically, pushing out the air. That is, here the protective film 7 also plays the role of a guide that guides the encapsulation resin 8 to be injected. After the injection of the encapsulation resin 8, for example, if the encapsulation resin 8 is an ultraviolet curing type, the encapsulation resin 8 is cured by UV irradiation.

[0025] After the steps shown in Figure 7, multiple (in this case, four) individual organic EL elements 2 are created by appropriately dividing the mother board 1 and removing the protective film 7 using the same steps as shown in Figures 3 to 5 of Example 1.

[0026] As described above, in Example 2, similar to Example 1, the electrode region 6 is covered with the protective film 7 before the sealing resin 8 is applied (injected) into the display region 5, thus preventing the sealing resin 8 from adhering to the electrode region 6. Furthermore, in Example 2, the protective film 7 is also used (combined) as an adhesive member to bond the first substrate 3 and the second substrate 4, thus simplifying the manufacturing process compared to the case where such an adhesive member is provided separately.

[0027] The present invention is not limited to the embodiments described above, and various other embodiments are possible. [Explanation of symbols]

[0028] 1 Motherboard 2 Organic EL elements 3 First board 4 Second board 5 Display area 6 electrode area 7 Protective film 8 Sealing resin 10 Disconnected wires 11 Disconnected wires 12 Holding container 13 Spacers

Claims

1. A method for manufacturing an organic EL element, comprising a first substrate having a display area on which a light-emitting layer is formed and an electrode area on which electrode terminals are formed, and a transparent second substrate, with a sealing resin interposed between them so as to cover the display area, The process includes a protective film forming step in which a protective film is formed on the electrode region before covering the display region with the sealing resin. A method for manufacturing an organic EL element, characterized by the above.

2. After the protective film forming step, a sealing resin coating step is performed in which the sealing resin is applied to the first substrate so as to cover the display area. The process includes a substrate bonding step of bonding the first substrate and the second substrate via the sealing resin applied to the first substrate in the sealing resin coating step. A method for manufacturing an organic EL element according to claim 1.

3. The method for manufacturing an organic EL element according to claim 2, characterized in that the sealing resin is applied so as to be thicker than the protective film.

4. A substrate bonding step comprising: forming the protective film with an adhesive material, and bonding the first substrate and the second substrate via the protective film made of the adhesive material; The process includes a sealing resin injection step in which the sealing resin is injected into the gap between the first substrate and the second substrate formed by the substrate bonding step, so as to cover the display area. A method for manufacturing an organic EL element according to claim 1.

5. The method for manufacturing an organic EL element according to claim 4, characterized in that the first substrate is provided with a plurality of organic EL element formation regions, the protective film is formed continuously across adjacent formation regions in a predetermined direction, and the sealing resin is injected along the predetermined direction.

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