JP4486840B2 - Display device and manufacturing method thereof - Google Patents

Description

  The present invention relates to a display device and a method for manufacturing the display device.

    In recent years, organic EL (Electro Luminescence) displays have attracted attention as FPD (Flat Panel Display). The organic EL display includes a display panel in which a plurality of organic EL elements serving as pixels are arranged. A display panel usually includes an element substrate on which an organic EL element is formed and a sealing counter substrate facing the element substrate. By providing a water-absorbing material on the sealing counter substrate and bonding the element substrate and the sealing counter substrate and sealing the region where the organic EL element is provided, deterioration due to moisture in the atmosphere is prevented. .

  In the organic EL display device, a part of the counter substrate for sealing is dug to provide a concave portion to form a water catching material storage portion. This water catching material storage part is provided in the display area in which the organic EL element is provided. And after storing a water catching material in a water catching material storage part, a sealing material is apply | coated to the convex part around a recessed part, and it is bonded with the element substrate. Thereby, a water catching material can be provided in the space where the organic EL element is sealed with the two substrates and the sealing material. This water-absorbing material functions as a desiccant, adsorbs moisture present in the sealed space, and prevents deterioration of the organic EL element. Moreover, the manufacturing method which provides a recessed part further in the outer periphery of the convex part for providing a sealing material is disclosed (patent document 1).

However, in the conventional organic EL display device, since the etching process is performed on the transparent substrate such as glass to make a digging, it is difficult to control the thickness. In addition, forming a concave portion having a complicated shape results in an increase in cost, and further, the number of manufacturing steps increases, resulting in a decrease in productivity.
JP 2002-343557 A

  As described above, the conventional method for manufacturing an organic EL display panel has a problem in that productivity is lowered.

  The present invention has been made in view of such problems, and an object thereof is to provide a display device with excellent productivity and a method for manufacturing the same.

  The display device according to the first aspect of the present invention includes a first substrate (for example, the counter substrate 20 in the embodiment of the present invention) and a second substrate (for example, the element substrate 10 in the embodiment of the present invention). Is a display device disposed opposite to the display device, and a sealing material provided so as to surround a display region between the first substrate and the second substrate (for example, the sealing material in an embodiment of the present invention) 23) and a convex portion formed on the surface of the first substrate and arranged to restrict the position of the sealing material outside the sealing material (for example, the first in the embodiment of the present invention) And a convex portion 25). Thereby, productivity can be improved.

  A display device according to a second aspect of the present invention is formed on the surface of the first substrate in the above-described display device, and is disposed inside the seal material to regulate the position of the seal material. 2 convex parts are further provided. Thereby, productivity can be improved.

  In the above display device, it is preferable that the sealing material is formed of a resin.

  In the display device according to the third aspect of the present invention, in the above-described display device, the sealing material includes a spacer that regulates a distance between the first substrate and the second substrate at a sealing material disposition position. It is provided. Thereby, a board | substrate space | interval can be adjusted.

In the display device according to the fourth aspect of the present invention, in the display device according to the first aspect of the present invention, the spacer is 1.02 times to 1.1 times the height of the convex portion. It is formed with the following height. Thereby, a board | substrate space | interval can be adjusted.
A display device according to a fifth aspect of the present invention is the above-described display device, wherein the first convex portion and / or the second convex portion includes a water catching material. Thereby, water catching performance can be improved.

  A method for manufacturing a display device according to a sixth aspect of the present invention includes a step of forming a convex portion on the surface of the first substrate, and a step of forming a sealing material so as to surround the display region inside the convex portion. And bonding the first substrate and the second substrate via the sealing material. As a result, the display device can be manufactured with high productivity.

  The manufacturing method of the display device according to the seventh aspect of the present invention further includes a step of forming a second convex portion inside the convex portion, and the step of forming the sealing material includes the first convex portion. And the second convex portion are formed with a sealing material.

  According to the present invention, it is possible to provide a display device with high productivity and a manufacturing method thereof.

  Hereinafter, embodiments to which the present invention can be applied will be described. The following description is to describe the embodiment of the present invention, and the present invention is not limited to the following embodiment. For clarity of explanation, the following description is omitted and simplified as appropriate. Further, those skilled in the art will be able to easily change, add, and convert each element of the following embodiments within the scope of the present invention. In addition, what attached | subjected the same code | symbol in each figure has shown the same element, and abbreviate | omits description suitably.

  A method for manufacturing an organic EL display device according to the present invention will be described with reference to FIG. FIG. 1 is a flowchart showing a manufacturing process of an organic EL display device. The organic EL display device includes an organic EL display panel in which a plurality of organic EL elements serving as pixels are arranged. An organic EL display panel usually includes an element substrate on which an organic EL element is formed and a counter substrate disposed opposite to the element substrate for sealing the organic EL element.

  A method for manufacturing an element substrate including an organic EL element will be described. For example, a glass substrate having a thickness of 0.7 mm to 1.1 mm is used as the element substrate (step S101). As the glass substrate, alkali-free glass (for example, AN100 manufactured by Asahi Glass Co., Ltd.) or alkali glass (ASA manufactured by Asahi Glass Co., Ltd.) can be used. An ITO film serving as an anode electrode material is deposited on the glass substrate (step S102). ITO can be formed on the entire surface of the glass substrate with good uniformity by sputtering or vapor deposition. Here, the film is formed with a film thickness of 150 nm by a DC sputtering method. An ITO pattern is formed by photolithography and etching (step S103). This ITO pattern becomes the anode. A phenol novolac resin is used as the resist, and exposure development is performed. Etching may be either wet etching or dry etching. Here, ITO was patterned using a mixed aqueous solution of hydrochloric acid and nitric acid. Monoethanolamine was used as the resist stripping material.

  An auxiliary wiring material is deposited on the ITO pattern (step S104). The auxiliary wiring material is made of a low-resistance metal material such as Al or an Al alloy, and can be formed by sputtering or vapor deposition. Further, in order to improve adhesion to the base or prevent corrosion, a barrier layer such as TiN or Cr may be formed on the lower layer or upper layer of the Al film to form the auxiliary wiring in a laminated structure. This barrier layer can also be formed by vapor deposition or sputtering. Here, a Cr / Al / Cr laminated film or a MoNb / Al / MoNb laminated film having a total thickness of 450 nm is formed as an auxiliary wiring material by DC sputtering. The auxiliary wiring material is patterned by photolithography and etching to form an auxiliary wiring pattern (step S105). For the etching, an etching solution made of a mixed aqueous solution of phosphoric acid, acetic acid, nitric acid or the like can be used. It is also possible to form the anode material and the auxiliary wiring material in order, and then pattern the auxiliary wiring material and the anode material in order. A signal is supplied to the anode or the cathode by the auxiliary wiring pattern.

  Next, an opening insulating film is formed (step S106). As the insulating film, photosensitive polyimide is spin-coated, patterned after a photolithography process, and then cured to form an opening insulating film having a pixel opening in a pixel. At the same time, a contact hole between the cathode and the auxiliary wiring is formed. For example, the pixel opening is formed with a size of about 300 μm × 300 μm, and the contact hole between the cathode and the auxiliary wiring is formed with a size of about 200 μm × 200 μm.

  Next, a cathode barrier is formed (step S107). For the cathode partition, for example, novolac resin is used. A novolak resin is spin-coated, patterned by a photolithography process, and then photoreacted to form cathode barrier ribs. It is desirable to use a negative type photosensitive resin so that the cathode partition has an inversely tapered structure. When a negative photosensitive resin is used, when light is irradiated from above, the photoreaction becomes insufficient at deeper locations. As a result, when viewed from above, the cross-sectional area of the cured portion has a structure that is narrower on the lower side than on the upper side. This means that it has an inverted taper structure. With such a structure, the cathodes can be separated from each other because the portions that are shaded when viewed from the vapor deposition source during vapor deposition of the cathodes do not reach the vapor deposition. Further, oxygen plasma or ultraviolet light may be irradiated in order to modify the surface of the ITO layer in the opening.

  Next, an organic EL element is formed on the pixel opening (step S108). For example, an organic EL layer and a cathode are deposited using a deposition apparatus. The organic EL layer often includes an interface layer, a hole transport layer, a light emitting layer, an electron injection layer, and the like as constituent elements. However, it may have a different layer structure. The thickness of the organic EL layer is usually about 100 to 300 nm. Copper phthalocyanine (CuPc) is 10 nm thick as the interface layer, and N, N′-di (naphthalen-1-yl) -N, N′-diphenyl-benzidine (α-NPD) is 60 nm thick as the hole transport layer, Alq is deposited to a thickness of 50 nm as a light emitting layer, and LiF is deposited to a thickness of 0.5 nm as an electron injection layer. In the above structure, a triphenylamine-based material such as triphenyldiamine (TPD) can be used for the hole transport layer instead of α-NPD. Al is often used for the cathode, but alkali metals such as Li, Ag, Ca, Mg, Y, In and alloys containing them can also be used. The thickness of the cathode is usually about 50 to 300 nm, and here it is Al having a thickness of 200 nm. In addition, the cathode can be formed by physical vapor deposition (PVD) such as sputtering or ion plating. Thereby, an organic EL element is formed.

  Through these steps, an element substrate on which a plurality of organic EL elements are formed is manufactured. Usually, a plurality of organic EL display panels having a plurality of organic EL elements are formed on one substrate. Then, by cutting and separating each organic EL display panel, a plurality of organic EL display panels can be obtained from one mother glass. This process will be described later. The manufacturing process of the organic EL element substrate described above is an example of a manufacturing process of an element substrate used in a typical organic EL display device, and is not limited to the manufacturing process described above.

  Next, a manufacturing process of the counter substrate for sealing the organic EL element will be described. Since the organic EL element deteriorates due to moisture in the air or the like, the organic EL element is sealed using a counter substrate. A glass substrate having a thickness of 0.7 mm to 1.1 mm is used as the counter substrate (step S201), and the same substrate as the element substrate can be used.

  And the convex part for regulating the position of a sealing material is formed in the surface of a counter substrate (step S202). It is desirable to form the convex portions outside and inside the position where the sealing material is formed. By forming the convex portion on the outside, it is possible to prevent the sealing material from flowing out to the cutting line of the substrate. Therefore, occurrence of cutting defects can be reduced. Further, by forming the convex portion inside, it is possible to prevent the element from flowing out to the region where the element is formed. By providing the convex portion, the step of digging the substrate can be omitted, and productivity can be improved.

  The convex portion can be formed of an epoxy resin. Specifically, a curable resin is applied by printing or a dispenser, and a convex portion is formed by curing or the like. The resin is preferably a two-component or one-component epoxy resin, and is cured before application of the sealing material. Thereby, a convex part functions as a dam which prevents the outflow of a sealing material. Note that the resin may be a curable resin that is resistant to ultraviolet rays. Furthermore, it is desirable that the convex resin does not generate volatile substances or gases over a long period of time, has adhesiveness with glass at the time of formation, and has a change with time and deformation equivalent to or higher than that of the cured sealant.

  Next, a water catching material is disposed (step S203). Calcium oxide powder or the like is used as the water catching material. And a sealing material is apply | coated to the surface in which the convex part of the opposing board | substrate was provided using a dispenser (step S204). The sealing material is provided between the outer convex portion and the inner convex portion. Thereby, it can prevent that a sealing material flows out. As the sealing material, a photosensitive epoxy resin is desirable. For example, a photocationic polymerization type epoxy resin can be used, and it functions as an adhesive for bonding the element substrate and the counter substrate. The sealing material is kneaded with a spacer for keeping the distance between the element substrate and the counter substrate constant. Then, the sealing material 23 including the spacer 28 is applied. Thereby, the clearance gap for arrange | positioning a water catching material is formed.

  Next, the element substrate and the counter substrate are bonded together to seal the organic EL element (step S109). A configuration of an organic EL display panel formed by sealing the organic EL element will be described with reference to FIG. FIG. 2 is a plan view showing a configuration of cutting lines between the element substrate and the counter substrate. 10 is an element substrate, 11 is an organic EL element, 12 is an auxiliary wiring, 20 is a counter substrate, 23 is a sealing material, and 24 is a sealing material for preventing scattering.

  First, the overall configuration of the organic EL display panel will be described with reference to FIG. The element substrate 10 is provided with a plurality of organic EL elements 11 formed in steps S <b> 101 to S <b> 108 and auxiliary wirings 12 for supplying signals to each organic EL element 11. An auxiliary wiring 12 extends from the organic EL element 11 to the outside of the sealing material 23. By supplying a current to the organic EL element through the auxiliary wiring 12, the organic EL element 11 emits light and a desired image can be displayed. A region where the organic EL element 11 is formed becomes a display region.

  As shown in FIG. 2, the element substrate 10 serving as the mother glass is provided with six display regions, and is disposed so as to be opposed to the counter substrate 20 for sealing. The organic EL display panel 30 is formed by cutting and separating the two substrates. Even before the cutting and separation, the center side of each organic EL display panel after the cutting and separation is set to the inside, and the end side is set to the outside. A counter substrate 20 that is slightly smaller than the element substrate 10 is provided with a water capturing material 22 for each organic EL element 11. In FIG. 2, the water catching material is omitted for illustration.

  The counter substrate 20 is provided with a sealing material 23 so as to surround the entire circumference of each display region. Protrusions (not shown) for regulating the position of the sealing material 23 are formed on the inner side and the outer side of the sealing material 23. This convex portion will be described later. In this embodiment, in order to prevent scattering of the cut pieces when cutting, a scattering prevention sealing material 24 is provided between the sealing materials 23 surrounding each display area.

  The counter substrate 20 is provided with a sealing material 23 on the entire outer periphery of the organic EL element 11. The sealing material 23 is an adhesive such as an ultraviolet curable resin, and is applied by a dispenser. The counter substrate 20 and the element substrate 10 can be bonded together by irradiating and curing the sealing material 23 with UV light. Then, the element substrate 10 and the counter substrate 20 are aligned so as to face each other, both substrates are pressurized, and the sealing material is irradiated with UV light. Thereby, the sealing material 23 is cured and the element substrate 10 and the counter substrate 20 are bonded together.

  The substrate bonded by the above-described process is cut and divided into each organic EL display panel (step S110). Next, a drive circuit and the like are mounted (step S111). On the element substrate 10, auxiliary wiring 12 is extended outside from a region surrounded by the sealing material 23. A terminal portion is formed at the outer end portion of the auxiliary wiring 12, and an anisotropic conductive film (ACF) is attached to the terminal portion to connect a TCP (Tape Carrier Package) provided with a drive circuit. Specifically, ACF is temporarily crimped to the terminal portion. ACF uses Hitachi Chemical Anisolm 7106U. The temporary pressure bonding temperature is 80 ° C. and the pressure bonding pressure is 1.0 MPa. Next, the TCP with the built-in drive circuit is finally bonded to the terminal portion. The main pressure bonding temperature is 170 degrees and the pressure bonding pressure is 2.0 MPa. Thereby, a drive circuit is mounted. The organic EL display panel 30 is attached to the housing, and the organic EL display device is completed (step S112).

  Through the above-described steps, the organic EL display panel 30 shown in FIG. 3 is formed. FIG. 3 is a cross-sectional view schematically showing the configuration of the organic EL display panel 30. In FIG. 3, the drive circuit and the like are not shown. As shown in FIG. 3, an organic EL element 11 is provided in the display area of the element substrate 10. A water catching material 22 for preventing deterioration of the organic EL element 11 due to moisture in the air is provided at a position facing the organic EL element 11 of the counter substrate 20. The water capturing material 22 captures moisture in the space where the organic EL element 11 is sealed, and prevents the organic EL element 11 from deteriorating. In the sealing step, nitrogen gas may be filled.

  A first convex portion 25 is formed outside the sealing material 23. Further, a second convex portion 27 is formed inside the sealing material 23. That is, the sealing material 23 is formed between the first convex portion 25 and the second convex portion 27. The water catching material 22 is provided inside the second convex portion 27 and is disposed in the display area.

A configuration in the vicinity of the sealing material 23 will be described with reference to FIG. FIG. 4 is an enlarged cross-sectional view schematically showing the configuration in the vicinity of the sealing material 23 in the sealing step. On the surface of the element substrate 10, the first convex portion 25 is formed of resin outside the position where the sealing material 23 is applied. The second convex portion 27 is formed of resin inside the position where the seal material 23 is applied. The epoxy resin is cured before applying the sealing material to form the first convex portion 25 and the second convex portion 27. Thereby, the first convex portion 25 and the second convex portion 27 provided on the counter substrate 20 function as a dam that prevents the sealing material 23 from flowing out. Then, the sealing material 23 is applied between the first convex portion 25 and the second convex portion 27. The seal material 23 includes a spacer 28 for restricting the distance between the element substrate 10 and the counter substrate 20 at the position where the seal material is disposed. The spacer 28 can control the gap between the substrates. The sealing material 23 is applied higher than the first convex portion 25 and the second convex portion 27.

  Positioning is performed so that the element substrate 10 and the counter substrate 20 face each other, and both substrates are pressurized. Thereby, the sealing material 23 before hardening flows out between the convex part and the element substrate 10, and it becomes a structure shown in FIG.4 (b).

  Then, as shown in FIG. 4C, the distance between the element substrate 10 and the counter substrate 20 is reduced to the height of the spacer 28. Since the spacer 28 is provided on the sealing material 23, the substrate interval does not become narrower than the spacer 28. The spacer 28 preferably has a height of 1.02 to 1.1 times the height of the first convex portion 25 and the second convex portion 27. A gap is generated between the top surface of the convex portion and the element substrate 10. When both substrates are pressurized, the sealing material 23 flows out into this gap. That is, the sealing material 23 formed higher than the convex portion is crushed and flows out between the top surface of the convex portion and the element substrate 10. The outflow amount of the sealing material 23 is controlled by the height of the convex portion and the height of the spacer 28. In this state, the sealing material 23 is irradiated with UV light. As a result, both substrates are bonded.

  The heights of the first convex portion 25 and the second convex portion 27 are determined based on the distance formed between the element substrate 10 and the counter substrate 20. That is, the heights of the first convex portion 25 and the second convex portion 27 are determined based on the thickness of the organic EL element 10 and the height of the water catching material 22. By making the height of the first convex portion 25 and the second convex portion 27 larger than the total height of the organic EL element 10 and the water catching material 22, the water catching material 22 becomes an organic EL element. 11 can be prevented from contacting. When the height of the organic EL element 11 and the water catching material 22 is taken into consideration, the height of the first convex portion 25 and the second convex portion 27 is, for example, about 0.3 mm. When the height of the water catching material 22 is not taken into account, the total thickness of the organic EL element 11 is about 0.2 μm. Therefore, if only the surface tension and wettability of the resin are taken into consideration, the first convex portion 25 and the second convex portion The height of the portion 27 is about 0.1 mm.

  The first convex portion 25 and the second convex portion 27 are formed of epoxy resin as described above. Thereby, it is not necessary to dig a substrate in order to arrange the water catching material 22, and the water catching material 22 can be placed on the substrate having a flat surface. Therefore, the substrate etching step can be omitted and productivity can be improved. Furthermore, spacers 28 are provided in the sealing material 23 in order to keep the substrate interval constant. By providing the 1st convex part 25 on the outer side of the sealing material 23, it can prevent that the sealing material 23 flows out to a cutting line. Therefore, cutting defects can be reduced and productivity can be improved. Further, by forming the second convex portion 27 inside the sealing material 23, it is possible to prevent the sealing material 23 from flowing out to the organic EL element 11 and the water catching material 22. Therefore, it is possible to prevent a decrease in display quality. By kneading the spacer 28 in the sealing material 23, the spacer 28 can be provided without increasing the number of manufacturing steps, and productivity can be improved. Further, by adjusting the heights of the convex portions and the spacers 28, the amount of protrusion of the sealing material 23 can be easily controlled.

  It is desirable that the first convex portion 25 and the second convex portion 27 are continuously provided so as to surround the entire sealing material 23. By continuously forming the convex portions, the sealing material 23 is formed in a frame shape surrounding the whole. Thereby, it can prevent that the sealing material 23 flows out. In addition, it is also possible to form a convex part intermittently if it is a grade which is not influenced by the balance of the surface tension and wettability of resin. For example, the first convex portion 25 or the second convex portion 27 may be missing with a width of about 0.1 mm. Further, when it is desired to prevent the seal material 23 from flowing out only to a specific portion, the convex portions may be formed intermittently.

  Since the water capturing material is disposed in the space surrounded by both the substrates and the sealing material 23, it is possible to prevent deterioration of the organic EL element due to moisture remaining or entering the sealed space. Since the 1st convex part 25 and the 2nd convex part 27 which were provided in the vicinity of the sealing material 23 have tolerance with respect to an ultraviolet-ray, a volatile substance does not volatilize in sealing space.

  In the above description, the sealing material 23, the first convex portion 25, and the second convex portion 27 are formed on the counter substrate 20, but may be formed on the element substrate 10. Further, the first convex portion 25 and the second convex portion 27 may have different heights. In this case, it is preferable to use a spacer 28 having a height of 1.02 to 1.1 times the height of the higher convex portion. Furthermore, water-capturing performance can be improved by kneading a water-absorbing material with the epoxy resin that becomes the first convex portion 25 or the second convex portion 27.

It is a flowchart which shows the manufacturing process of the organic electroluminescence display concerning this invention. It is a top view which shows the structure before the cutting | disconnection of the organic electroluminescent display panel concerning this invention. It is sectional drawing which shows the structure of the organic electroluminescence display panel concerning this invention. It is an expanded sectional view which shows the structure of the sealing material periphery at the time of sealing of the organic electroluminescent display apparatus concerning the Example of this invention.

Explanation of symbols

10 element substrate 11 organic EL element 12 auxiliary wiring 20 counter substrate,
22 Water catching material 23 Sealing material 24 Spattering preventing sealing material 25 First convex portion 27 Second convex portion 28 Spacer 30 Organic EL display panel 40 Cutting line 50 of opposing substrate Cutting line of element substrate

Claims (7)

A display device in which a first substrate and a second substrate are arranged to face each other,
A sealing material provided so as to surround a display region between the first substrate and the second substrate;
A first protrusion formed on the surface of the first substrate and disposed on the outside of the sealing material to regulate the position of the sealing material ;
A second protrusion formed on the surface of the first substrate and disposed inside the sealing material to regulate the position of the sealing material,
The seal material includes a spacer that regulates a distance between the first substrate and the second substrate, and the spacer is higher than the height of the first protrusion and the second protrusion. And
A display device in which a sealing material is interposed between the top surface of the first protrusion and the top surface of the second protrusion and the second substrate . 2. The display device according to claim 1 , wherein the spacer is formed at a height of 1.02 times or more and 1.1 times or less of a height of the first protrusion and the second protrusion. The display device according to claim 1, wherein a water catching material is included in the first convex portion and / or the second convex portion. The display device according to claim 1, wherein the sealing material is an ultraviolet curable resin . 4. The display device according to claim 1, wherein the first substrate is a counter substrate, and the second substrate is an element substrate including an organic EL element. Forming a first protrusion on the surface of the first substrate;
Forming a sealing material so as to surround the display area inside the first convex portion;
Bonding the first substrate and the second substrate through the sealing material;
Forming the second convex portion inside the first convex portion, and
In the step of forming the sealing material,
Forming a sealing material between the first convex portion and the second convex portion, and including a spacer higher than the height of the first convex portion and the second convex portion in the sealing material;
The sealing material is applied higher than the first convex portion and the second convex portion, and the sealing material is interposed between the first convex portion, the second convex portion, and the second substrate. A method for manufacturing a display device to be poured . The method for manufacturing a display device according to claim 6, wherein a water catching material is included in the first convex portion and the second convex portion.

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