JP2006024459A - Organic el display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic EL display device having an insulation film on non-light-emitting areas between pixels, preventing short-circuit between upper and lower electrodes to the utmost when a reverse bias voltage is impressed. <P>SOLUTION: The organic EL display device S1 is composed of a plurality of pixels 50 formed by laminating a lower electrode 20, an organic film 30 including a light-emitting layer 33, and an upper electrode 40 on a substrate 10; and insulation films 60 formed between the pixels 50 on the substrate 10. The insulation film 60 contains at least one compound selected from a group of silane compound having a heat-resistant temperature of about 540 °C, a hydrolytic compound thereof, and a condensation compound of the hydrolytic compound. A reverse bias voltage making a field strength become 1.5 MV/cm or higher can be impressed on the pixels. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an organic EL (electroluminescence) display device, and more particularly to an organic EL display device having an insulating film in a non-light emitting region between pixels.

  A general organic EL display device has a plurality of pixels in which a lower electrode, an organic film including a light emitting layer, and an upper electrode are stacked on a substrate. Here, the organic film exhibits diode characteristics and emits light by applying a forward bias between the upper and lower electrodes in the pixel.

  Since this organic EL display device can be driven at a low voltage of several volts to several tens of volts, it has low power consumption and can be reduced in weight including a drive circuit. It is expected to be used in various ways such as next-generation thin displays, flat lighting, and thin backlights.

  However, the organic EL display device is easy even if the organic film between the electrodes is extremely thin (for example, on the order of submicron), and the defect portion (film defect portion) generated in the electrode film or the organic film is very small. However, there is a problem that current concentrates on the light source, resulting in non-light emission.

  The cause of this minute defect is the inclusion of foreign matter such as dust and dust generated when forming a film such as an electrode or an organic film, but a uniform film with no such defects is formed in a large area. Is very difficult.

  Therefore, in the device manufacturing process, it is conceivable to perform an aging process in which a reverse bias voltage is applied between the anode and the cathode to cause the film defect portion to be open broken in advance. Open breakdown is to make a defective part non-conductive, and the electrode corresponding to the film defective part is destroyed by Joule heat generated during aging to be in an open state (insulated state) or oxidized to be non-conductive. It may be caused by a phenomenon such as

  The film defect part that has undergone such open breakdown becomes a local non-light-emitting part, but the problem film defect part is a minute one that cannot be visually recognized from the beginning, and does not affect the display quality. There is no.

  In order to perform open breakdown by such aging, the breakdown voltage of the defective portion and the breakdown voltage of the organic EL element are obtained in advance, and the aging treatment is performed in a voltage range between these both breakdown voltages, thereby obtaining a normal portion. There has been proposed a method in which only a defective portion is open broken without breaking (see, for example, Patent Document 1).

  On the other hand, a conventional organic EL display device includes an insulating film disposed between pixels on a substrate.

  As described above, the organic film exhibits diode characteristics and emits light when a forward bias voltage is applied between the upper and lower electrodes. In a passive matrix (simple matrix) panel, display is performed with light-emitting pixels and non-light-emitting pixels. In order to obtain a non-light-emitting display, a diode, that is, an organic diode is used even during driving in order to prevent crosstalk between pixels. It is necessary to apply a reverse bias voltage to the film. Conventionally, the reverse bias voltage may be about the same as the forward bias voltage, for example, about 10V to 13V.

  A current that flows when a reverse bias voltage is applied is referred to as a leakage current. However, the larger the current value, the lower the breakdown voltage of the device, and there is a problem that the upper and lower electrodes are short-circuited when operated for a long time. This short-circuiting of electrodes causes bright lines or dark lines on the line to be generated on the panel, causing problems in display.

  As described above, since the organic film between the electrodes in the organic EL display device is extremely thin (for example, on the order of submicron), the organic film is covered when the surface of the lower part (underlayer) of the organic film is uneven. This is because it cannot be exhausted. In other words, if there are irregularities on the underlying surface of the organic film, electric field concentration occurs on the irregularities, causing dielectric breakdown of the organic film, causing a short circuit between the upper and lower electrodes.

  In particular, in a panel where a plurality of strip-shaped electrode patterns of a passive matrix intersect, the unevenness on the surface edge of the pattern edge of the lower electrode is large, so that the organic film thickness is locally thinned at the edge of the lower electrode, and the short circuit is significant. Become.

  Therefore, a flat insulating film that covers the pattern edge is required. That is, it becomes necessary to provide an insulating film between lower electrodes between pixels, that is, in a non-light emitting region.

  By the way, for example, in the case where the lower electrode and the upper electrode in a stripe shape intersect, the insulating film is disposed between the lower electrodes between the respective pixels and on the portion of the lower electrode located between the upper electrodes. As a result, a lattice shape is formed. However, the peripheral portion of the insulating film enters between the upper and lower electrodes and is sandwiched between the upper and lower electrodes.

  In other words, such an insulating film is an insulating film between the upper and lower electrodes applied to a region that does not emit light (that is, a non-light emitting region) with an area that actually emits light as an opening, and is patterned by this insulating film. Only the opening can be energized, and light emission with high pattern accuracy can be obtained only in that portion. The insulating film is also a layer that keeps electrical insulation by preventing a short circuit between the upper and lower electrodes even when no light emitting layer exists between the upper and lower electrodes (anode and cathode).

For this reason, conventionally, an organic EL display device in which an insulating film is arranged between each pixel on a substrate has been proposed (see, for example, Patent Document 2 and Patent Document 3). Such an insulating film is not particularly limited as long as it is a film made of a material that is an insulator. For example, a radiation-sensitive composition is employed (see, for example, Patent Document 4).
JP 2003-282253 A Japanese Patent No. 2734464 Japanese Patent No. 2911552 JP 2003-288991 A

  However, even in such an insulating film, there is a minute defect due to contamination of foreign matters.

  According to the study of the present inventor, when a reverse bias voltage is applied to an insulating film having such a defective portion, the defective portion in the insulating film or A new problem has been discovered in which a current flows through a defect near the insulating film edge, the insulating film is deformed, the upper and lower electrodes are short-circuited at the deformed portion, and non-light emission occurs.

  Therefore, in view of the above problems, an object of the present invention is to prevent the upper and lower electrodes from being short-circuited as much as possible in an organic EL display device having an insulating film in a non-light emitting region between pixels.

  In order to achieve the above object, intensive studies were conducted.

  In general, an inorganic insulating film may be used to satisfy the heat resistance of the insulating film. However, in the case of an inorganic insulating film, at the edge of the insulating film, the edge shape is not low taper or the unevenness is large, so that a thin film part is formed in the organic film, and leakage occurs from there, This leads to a short circuit between the upper and lower electrodes.

  Therefore, a lift-off process for making the edge portion of the insulating film into a low taper shape, a polishing process for reducing unevenness, and the like are required. However, polishing of the stepped portion is not easy, and it is difficult to reduce the unevenness at the edge portion of the insulating film and suppress the leakage of the organic film.

  On the other hand, there are many organic materials that can realize a low taper shape or a shape with small unevenness without requiring these special processes. Therefore, it was considered to use an organic material as the insulating film.

  However, organic materials generally have low heat resistance, and most of them lead to display defects. Therefore, organic materials with relatively high heat resistance were selected and examined. The present invention has been experimentally found based on the examination results.

  That is, in the first aspect of the invention, a plurality of layers are formed by laminating the lower electrode (20), the organic film (30) including the light emitting layer (33), and the upper electrode (40) on the substrate (10). The organic EL display device having the pixel (50) and the insulating film (60) disposed between the pixels (50) on the substrate (10) has the following characteristic points.

  The insulating film (60) contains at least one compound selected from the group consisting of a silane compound represented by the following chemical formula (1), a hydrolyzate thereof, and a condensate of the hydrolyzate. .

(Chemical formula 2)
(R1) _p Si (X) _4-p (1)
Here, in the chemical formula (1), R1 is a non-hydrolyzable organic group having 1 to 12 carbon atoms, X is a hydrolyzable group, and p is an integer of 0 to 3.

  The pixel (50) is in a light emitting state when a forward bias voltage is applied, and the electric field Ya is as follows when the reverse bias voltage is Vr and the thickness of the organic film (30) is Dy. And a reverse bias voltage such that the electric field Ya is 1.5 MV / cm or more can be applied to the pixel (50).

(Equation 2)
Ya = Vr / Dy (2)
The organic EL display device of the present invention is characterized by these points.

  According to this, in order to solve the problem that the insulating film is thermally deformed and the upper and lower electrodes are short-circuited, if a silane compound having a heat resistant temperature of about 540 ° C. is used as the insulating film (60), the organic EL display device is practically used. In some cases, it was experimentally confirmed that a short circuit caused by thermal deformation of the insulating film can be prevented. The heat-resistant temperature of this silane compound is the same as the melting point of a general upper electrode.

  However, there is a possibility that a leak occurs in the defective portion of the insulating film, which leads to a short circuit between the upper and lower electrodes. Therefore, it is necessary to open the electrode in the defective portion, that is, to destroy and fly the upper electrode immediately above the defective portion.

  However, since the heat resistance of the insulating film is increased, the heat resistance of the portion above the insulating film is also large. Then, with the reverse bias voltage during the conventional driving, it is difficult to skip the upper electrode on the insulating film.

  Therefore, in the present invention, a reverse bias voltage of 1.5 MV / cm or more, which is larger than the conventional reverse bias voltage as described above, can be applied to the pixel (50) (see FIG. 6).

  This has been found experimentally. When a reverse bias voltage of 1.5 MV / cm or more is applied to the pixel (50), the reverse bias is applied to the defective portion of the insulating film (60). The upper electrode (40) is skipped by the Joule heat of voltage, and the above opening can be realized.

  Thus, according to the present invention, in the organic EL display device having the insulating film (60) in the non-light emitting region between the pixels (50), the upper and lower electrodes (20, 40) are short-circuited when the reverse bias voltage is applied. It can be prevented as much as possible.

  In the second aspect of the present invention, a plurality of pixels (a plurality of pixels) in which a lower electrode (20), an organic film (30) including a light emitting layer (33), and an upper electrode (40) are laminated on a substrate (10). 50) and an organic EL display device having an insulating film (60) disposed between the pixels (50) on the substrate (10) has the following characteristic points.

  The insulating film (60) is made of an organic polymer material whose weight change at 540 ° C. is within 10%.

  The pixel (50) is in a light emitting state when a forward bias voltage is applied, and the electric field Ya is Vr when the reverse bias voltage is Vr and the thickness of the organic film (30) is Dy. The reverse bias voltage expressed by the mathematical formula (2) shown in the invention of claim 1 and having the electric field Ya of 1.5 MV / cm or more can be applied to the pixel (50). It has become. The organic EL display device of the present invention is characterized by these points.

  As described above, when the insulating film material is a heat resistant material, a short circuit caused by thermal deformation of the insulating film can be prevented. This is because when the upper electrode reaches a temperature close to the melting point (500 ° C. or more) due to Joule heat, the insulating film retains its shape, so that the upper and lower electrodes can be prevented from being short-circuited due to thermal deformation of the insulating film.

  In particular, as a definition of heat resistance, in the case of organic polymers, since a clear melting point cannot be defined, the present inventor has derived a new heat resistance index. That is, the temperature at which the weight loss rate is 10% in TGA (thermogravimetric analysis) is the heat resistant temperature.

  In the insulating film, if the temperature at which the weight reduction rate is 10% is 540 ° C. or higher, the insulating film (60) retains its shape and prevents the upper and lower electrodes from being short-circuited due to thermal deformation of the insulating film. It was found experimentally (see FIG. 7). This is particularly effective when the upper electrode (40) is Al.

  Further, in the present invention, similarly to the first aspect of the present invention, a reverse bias voltage that is 1.5 MV / cm or more larger than the conventional reverse bias voltage can be applied to the pixel (50). ing.

  According to this, since the reverse bias voltage of 1.5 MV / cm or more can be applied to the pixel (50) as in the case of the first aspect of the invention, the reverse is applied to the defective portion of the insulating film (60). The upper electrode (40) is skipped by the Joule heat of the bias voltage, and the opening can be realized.

  Thus, according to the present invention, in the organic EL display device having the insulating film (60) in the non-light emitting region between the pixels (50), the upper and lower electrodes (20, 40) are short-circuited when the reverse bias voltage is applied. It can be prevented as much as possible.

  Here, as in the invention according to claim 3, in the organic EL display device according to claim 1 or 2, the plurality of pixels (50) include a lower electrode (20) having a stripe shape. It is arranged in a grid formed by upper electrodes (40) in a stripe shape orthogonal to this, and between the lower electrodes (20) and between the lower electrodes (20) between the respective pixels (50). Of these, the insulating film (60) can be disposed on the portion located between the upper electrodes (40).

  In the organic EL display device according to any one of claims 1 to 3, as in the invention according to claim 4, the insulating film (60) is not in a porous state at the time of dielectric breakdown. It is preferably made of a material that becomes an aggregated state.

  Here, the porous state is one in which many voids are generated at the time of dielectric breakdown and becomes a network, and is easily deformed. Moreover, the aggregation state is a state in which a bulk state is maintained at the time of dielectric breakdown.

  Since the breakdown shape of the insulating film (60) is not porous but is in an agglomerated state, the upper electrode (40) can be prevented from being involved due to thermal deformation of the insulating film (60), and the upper and lower electrodes can be short-circuited. It becomes easy to prevent.

  In the invention according to claim 5, in the organic EL display device according to claims 1 to 4, when a reverse bias is applied, a current of 40 mA or more is supplied to the pixel (50). It is characterized by becoming.

  As described above, a voltage with an electric field Ya of 1.5 MV / cm or more is applied to the pixel (50) as a reverse bias voltage. This electric field is applied from an external drive circuit.

  However, circuit wiring resistance and panel wiring resistance exist between the pixel (50) and the driving circuit. If these wiring resistances are large, the output in the circuit is 1.5 MV / cm or more, but the pixel (50) has an electric field smaller than that, and the above-described opening may not be realized. There is.

  Therefore, the current supplied to the pixel (50) at the time of applying the reverse bias voltage is used as a set value in consideration of such wiring resistance. Then, the present inventor has investigated how much this current can be made open.

  As a result, as in the present invention, when a current of 40 mA or more is supplied to the pixel (50) when a reverse bias is applied, the reverse bias voltage Joule is formed at the defective portion of the insulating film (60). It was found that the upper electrode (40) can be skipped by heat, and the above-mentioned opening is appropriately performed (see FIG. 8).

  In addition, the code | symbol in the bracket | parenthesis of each said means is an example which shows a corresponding relationship with the specific means as described in embodiment mentioned later.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following drawings, parts that are the same or equivalent to each other are given the same reference numerals in the drawings for the sake of simplicity.

  FIG. 1 is a schematic plan view of an organic EL display device S1 according to an embodiment of the present invention. In FIG. 1, the outer shape of the anode 20 and the outer shape of the insulating film 60 other than the portion hidden under the partition wall 70 are shown transparently, and the insulating film 60 is hatched.

  2 is a schematic cross-sectional view taken along line AA in FIG. 1, and FIG. 3 is a schematic cross-sectional view taken along line BB in FIG.

  The organic EL display device S1 includes a substrate 10 transparent to visible light. On the substrate 10, an anode 20 as a lower electrode, an organic film 30 including a light emitting layer 33 made of an organic EL material, electron injection A plurality of pixels 50 are formed as a stacked body in which the layer 35 and the cathode 40 as the upper electrode are sequentially stacked.

  The substrate 10 is a transparent electrically insulating substrate made of glass or resin, and in this example, a glass substrate is adopted.

  The anode 20 formed on the substrate 10 is made of a transparent conductive film such as an indium-tin oxide (ITO) film or an indium-zinc oxide film. It is about 1 μm, preferably about 150 nm.

  The organic film 30 is formed by a vacuum deposition method, and in order from the anode 20 side, a hole injection layer 31 made of a hole injecting organic material and a hole transport made of a hole transporting organic material. A layer 32, a light emitting layer 33 made of an organic EL material doped with a fluorescent dye in a hole transporting organic material or an electron transporting organic material, and an electron transporting layer 34 made of an electron transporting organic material are laminated.

  Specifically, the hole injection layer 31 formed on the anode can employ a hole injecting material that can be generally used for an organic EL panel. In this example, the hole injection layer 31 is formed of a copper phthalocyanine (CuPc) film having a thickness of 15 nm.

  The hole transport layer 32 formed on the hole injection layer 31 can employ a hole transport material that can be generally employed in an organic EL panel. In this example, the hole transport layer 32 is formed of an α-naphthyl phenyl benzene (NPD) film.

  For the light emitting layer 33 thereon, a material of a light emitting layer that can be usually employed in an organic EL panel, that is, a dopant material that is a host material and a fluorescent dye can be employed. And the luminescent color of the light emitting layer 33 can be prescribed | regulated mainly by changing dopant material.

  In this example, the light emitting layer 33 is formed of a film in which 1 wt% of dimethylquinacridone as a dopant, that is, a fluorescent dye, is added to Alq3 (aluminum quinolinol) as a host.

  And the electron transport layer 34 formed on the light emitting layer 33 can employ | adopt the electron transport material normally employable for an organic EL panel. In this example, the electron transport layer 34 is formed of an Alq3 film. In this example, the film thickness of the organic film 30 (the above films 31 to 34) is about 133 nm.

  As the electron injection layer 35 and the cathode 40 formed on the electron transport layer 34, an electron injection material and a cathode material that can be usually used for an organic EL panel can be used.

  In this example, the electron injection layer 35 is a 0.5 nm thick film made of lithium fluoride (LiF), and the cathode 40 as the upper electrode is a 100 nm thick film made of aluminum (Al). When the electron injection layer 35 is made of an organic material, the electron injection layer 35 is configured as a part of the organic film 30.

  The arrangement form of the pixels 50 in the present embodiment is as follows. A plurality of anodes 20 and cathodes 40 are provided, and the plurality of anodes 20 and the plurality of cathodes 40 are arranged in stripes extending in directions orthogonal to each other. The organic film 30 sandwiched between the electrodes 20 and 40 is patterned in the same stripe shape as the cathode 40.

  A portion of the laminate in which the anode 20 and the cathode 40 intersect and overlap each other forms a pixel 50 as a light emitting portion. In this example, as shown in FIG. The shape is arranged in a shape.

  Here, as shown in FIGS. 1 to 3, an electrically insulating insulating film 60 is formed between the stripes of the anode 20 and between the stripes of the organic film 30 and the cathode 40. That is, the insulating film 60 is disposed between the respective pixels 50 on the substrate 10 and is configured as a pixel separation layer.

  In other words, in this example, the plurality of pixels 50 are arranged in a grid formed by the anode 20 having a stripe shape and the cathode 40 having a stripe shape perpendicular to the anode 20. These are disposed between the anodes 20 between the respective pixels 50 and on portions of the anodes 20 located between the cathodes 40.

  As shown in FIGS. 1 and 3, the peripheral portion of the insulating film 60 enters between the upper and lower electrodes 20 and 40 and is sandwiched between the upper and lower electrodes 20 and 40. The same applies to the conventional organic EL display device. That is, the portions of the upper and lower electrodes 20 and 40 sandwiching the insulating film 60 are portions that are likely to cause a short circuit due to a defective portion of the insulating film 60.

  Here, the insulating film 60 contains at least one compound selected from the group consisting of a silane compound, a hydrolyzate thereof and a condensate of the hydrolyzate. The starting temperature is approximately 540 ° C.

  Preferably, the insulating film 60 is made of an organic polymer material whose weight change at 540 ° C. is within 10%. This change in weight is determined by TGA (thermogravimetric analysis). Details of the insulating film 60 will be described later.

  In addition, a plurality of partition walls 70 are formed in stripes on a portion of the insulating film 60 located between the stripes of the organic film 30 and the cathode 40. The partition wall 70 is made of a negative photosensitive resin resist material or the like.

  Further, as shown in FIG. 2, the cross-sectional shape of the partition wall 70 is an inversely tapered shape that spreads upward from the substrate 10 side. The cross-sectional shape of such a reverse taper in the partition wall 70 is for appropriately defining the organic film 30 and the cathode 40 in the film forming process of the organic film 30 and the cathode 40.

  As a result, in the organic EL display device S1, each pixel 50 is partitioned and separated by the partition wall 70 formed along the stripe direction of the cathode 40. Specifically, the organic film 30 and the cathode 40 are defined in stripes by the partition wall 70 and the adjacent cathodes 40 are insulated from each other.

  In such an organic EL display device S1, the light emitting layer 33 in the pixel 50 emits light by applying a voltage between the electrodes 20 and 40.

  Specifically, driving is performed by applying a voltage between the upper and lower electrodes 20, 40 using the lower electrode 20 as an anode and the upper electrode 40 as a cathode. At this time, a forward bias voltage is applied to the pixel 50 during light emission to emit light, and a reverse bias voltage is applied to suppress light emission due to crosstalk or the like when light is not emitted.

  Specifically, in the dot matrix type organic EL display device of this example, a pulse voltage of a drive waveform having a predetermined duty ratio and pulse width is applied to one pixel 50. When the forward bias voltage (forward pulse) is applied, the light emitting layer 33 emits light, and when the reverse bias voltage (reverse bias pulse) is applied, the light emitting layer 33 enters a non-light emitting state.

  Here, in this embodiment, when the electric field is Ya, the reverse bias voltage is Vr, and the thickness of the organic film 30 is Dy, the relationship of Ya = Vr / Dy is set. A reverse bias voltage with which the intensity, that is, the electric field Ya is 1.5 MV / cm or more can be applied to the pixel 50. In this example, the thickness Dy of the organic film 30 is 133 nm as described above, and the reverse bias voltage is 20 V or more.

  The reverse bias voltage at which the electric field Ya is 1.5 MV / cm or more is lower than the withstand voltage of the pixel 50 but larger than the conventional reverse bias voltage. As will be described in detail later, this is because the upper electrode 40 is skipped by the Joule heat of the reverse bias voltage in the defective portion of the insulating film 60 to realize the opening.

  A manufacturing method of the organic EL display device S1 will be described based on the configuration of the above example. First, an ITO film is formed on the substrate 10 by sputtering, and this is patterned using a photolithographic technique to form the anode 20.

  Next, the insulating film 60 is formed on the substrate 10 and the anode 20 in a portion between the pixels 50. The insulating film 60 can be formed by using a photosensitive composition containing a silane compound, specifically, a radiation-sensitive composition as a raw material using a photolithography method. Will be described later.

  Further, a partition wall 70 for separating the organic film 30 and the cathode 40 is formed on the insulating film 60 by photolithography. In this example, a negative photosensitive resin resist to be a partition wall 70 is spin-coated on the entire surface of the substrate 10, and after baking this, the partition wall 70 is formed by exposure and development.

  Thereafter, the organic film 30 is formed and stacked on the anode 20 by a vacuum evaporation method or the like, and the cathode 40 is formed and stacked on the organic film 30 by a vacuum evaporation method or the like.

  Specifically, a CuPc film is formed as the hole injection layer 31 on the anode 20 by vapor deposition, and then an NPD film is formed as the hole transport layer 31. On top of this, vapor deposition is performed to form a light emitting layer 33 formed by doping Alq3 with 1% dimethylquinacridone.

  Thus, after forming the light emitting layer 33, the electron carrying layer 34 which consists of Alq3 is formed with a vapor deposition method. Thereafter, an LiF film as the electron injection layer 35 and an Al film as the cathode 40 are sequentially formed by vapor deposition.

  Thereby, on the substrate 10, the organic film 30 and the cathode 40 are laminated in a stripe shape on the anode 20 and the substrate 10 positioned between the partition walls 70. Thus, the organic EL display device S1 having the above-described lattice-like pixels 50 and the lattice-like insulating film 60 disposed between the pixels 50 is formed.

  In addition, as shown in FIG. 2 above, in practice, a film similar to the organic film 30 and the cathode 40 is laminated also on the upper end surface of the partition wall 70 by such a film forming method.

[Details of insulation film]
Next, the details of the insulating film 60 and the film forming method will be described.

  The insulating film 60 of this embodiment contains at least one compound selected from the group consisting of a silane compound represented by the following chemical formula (1), a hydrolyzate thereof, and a condensate of the hydrolyzate. .

(Chemical formula 3)
(R1) _p Si (X) _4-p (1)
Here, in the chemical formula (1), R1 is a non-hydrolyzable organic group having 1 to 12 carbon atoms, X is a hydrolyzable group, and p is an integer of 0 to 3.

  Examples of such an insulating film 60 include a silane compound that is an organic substance. An example of the structure of the silane compound used for the insulating film 60 is shown in FIGS. The silane compound shown in FIG. 4 is used as a base material, and it has photocurability by adding a compound that generates an acid or a base upon irradiation with radiation. 4A shows a random structure, and FIG. 4B shows a ladder structure.

  Specific examples of other silane compounds include, for example, tetrachlorosilane, tetraaminosilane, tetraacetoxysilane, tetramethoxysilane, tetraethoxysilane, tetrabutoxysilane, tetrasilane as silane compounds substituted with four hydrolyzable groups. Examples include phenoxysilane, tetrabenzyloxysilane, tetrapropoxysilane, and the like.

  Further, as a silane compound substituted with one non-hydrolyzable group and three hydrolyzable groups, methyltrichlorosilane, methyltrimethoxysilane, methyltriethoxysilane, methyltriisopropoxysilane, methyltributoxysilane , Ethyltrimethoxysilane, ethyltriethoxysilane, ethyltriisopropoxysilane, ethyltributoxysilane, butyltrimethoxysilane, pentafluorophenyltrimethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, d3-methyltrimethoxysilane , Nonafluorobutylethyltrimethoxysilane, trifluoromethyltrimethoxysilane and the like.

  Further, as silane compounds substituted with two non-hydrolyzable groups and two hydrolyzable groups, dimethyldichlorosilane, dimethyldiaminosilane, dimethyldiacetoxysilane, dimethyldimethoxysilane, diphenyldimethoxysilane, dibutyldimethoxysilane Etc.

  Moreover, as a silane compound substituted with three nonhydrolyzable groups and one hydrolyzable group, trimethylchlorosilane, hexamethyldisilazane, trimethylsilane, tributylsilane, trimethylmethoxysilane, tributylethoxysilane, etc., respectively Can be mentioned.

  Of these, silane compounds substituted with one non-hydrolyzable group and three hydrolyzable groups can be preferably used, and in particular, methyltrimethoxysilane, methyltriethoxysilane, methyltriisopropoxysilane, methyltrimethyl. Butoxysilane, phenyltrimethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, ethyltriisopropoxysilane, ethyltributoxysilane, and butyltrimethoxysilane are preferred. Such silane compounds may be used alone or in combination of two or more.

  In addition, the silane compound used in the insulating film 60 of the present embodiment is at least one compound selected from the group consisting of the above silane compound, a hydrolyzate thereof, and a condensate of the hydrolyzate, It is preferably a hydrolyzate of a silane compound or a condensate of the hydrolyzate.

  The conditions for hydrolyzing or condensing the silane compound are not particularly limited, but can be carried out by the steps shown below as an example.

  The silane compound, a predetermined amount of water, and a suitable solvent are placed in a container equipped with a stirrer, and stirred in an air atmosphere at a temperature of 0 ° C. to the boiling point of the solvent or the silane compound for about 1 to 24 hours. During the stirring, the reaction mixture can be concentrated by distillation or a solvent can be added as necessary.

  There is no restriction | limiting in particular as a solvent which can be used here, For example, organic solvents, such as alcohol and ether, etc. can be used. When a solvent is used, the amount used is usually 1000 parts by weight or less per 100 parts by weight of the silane compound.

  A catalyst can also be used when the silane compound is hydrolyzed or condensed. Examples of such a catalyst include metal chelate compounds, organic acids, inorganic acids, organic bases, inorganic bases and the like. As a metal chelate compound used as a catalyst, a titanium chelate compound, a zirconium chelate compound, an aluminum chelate compound, etc. can be mentioned, for example.

  Specific examples thereof include, for example, triethoxy mono (acetylacetonato) titanium, tri-n-propoxy mono (acetylacetonato) titanium, and tri-i-propoxy mono (acetylacetonato) titanium as titanium chelate compounds. , Tri-n-butoxy mono (acetylacetonato) titanium, tri-sec-butoxy mono (acetylacetonato) titanium, tri-t-butoxy mono (acetylacetonato) titanium, diethoxybis (acetylacetonate) ) Titanium, di-n-propoxy bis (acetylacetonato) titanium, di-i-propoxy bis (acetylacetonato) titanium, di-n-butoxy bis (acetylacetonato) titanium, di-sec-butoxy・ Bis (acetylacetonate) titanium Di -t- butoxy bis (acetylacetonate) titanium, monoethoxy-tris (acetylacetonate) and titanium.

  Specific examples of the organic acid used as the catalyst include, for example, acetic acid, propionic acid, butanoic acid, pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, oxalic acid, maleic acid, methylmalonic acid, adipine Acid, sebacic acid, gallic acid, butyric acid, melicic acid, arachidonic acid, mikimic acid, 2-ethylhexanoic acid, oleic acid, stearic acid, linoleic acid, linolenic acid, salicylic acid, benzoic acid, p-aminobenzoic acid, p- Examples include toluenesulfonic acid, benzenesulfonic acid, monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, trifluoroacetic acid, formic acid, malonic acid, sulfonic acid, phthalic acid, fumaric acid, citric acid, and tartaric acid.

  Specific examples of the inorganic acid used as the catalyst include hydrochloric acid, nitric acid, sulfuric acid, hydrofluoric acid, phosphoric acid and the like.

  Specific examples of the organic base used as the catalyst include, for example, pyridine, pyrrole, piperazine, pyrrolidine, piperidine, picoline, trimethylamine, triethylamine, monoethanolamine, diethanolamine, dimethylmonoethanolamine, monomethyldiethanolamine, triethanolamine, diazabicyclo. Examples include ochrane, diazabicyclononane, diazabicycloundecene, and tetramethylammonium hydroxide.

  Examples of the inorganic base used as the catalyst include ammonia, sodium hydroxide, potassium hydroxide, barium hydroxide, calcium hydroxide and the like.

  In these, it is preferable to use a metal chelate compound, an organic acid, or an inorganic acid as a catalyst, More preferably, it is a titanium chelate compound or an organic acid.

  These compounds can be used alone or in combination of two or more as a catalyst. The usage-amount of a catalyst is 10 parts weight or less normally with respect to 100 weight part of silane compounds, Preferably it is 0.001-10 weight part, More preferably, it is 0.01-10 weight part.

  The weight average molecular weight of the hydrolyzate of the silane compound and the condensate of the hydrolyzate is preferably 15,000 or less, more preferably 500 to 15,000, and 1,000 to 12,000. More preferably. By setting the weight average molecular weight within this range, it is possible to obtain a composition having an excellent balance between film formability and radiation sensitivity.

  In addition, it should be understood that the weight average molecular weight was measured as a weight average molecular weight in terms of polystyrene using gel permeation chromatography (hereinafter, sometimes abbreviated as “GPC”).

  As described above, the insulating film 60 of the present embodiment can be formed using a photosensitive composition containing a silane compound, specifically, a radiation-sensitive composition as a raw material using a photolithography method. Therefore, in making the raw material, compounds added to the silane compound include a compound that generates an acid or a base upon irradiation with radiation, a silane coupling agent, and a dehydrating agent.

  First, examples of the compound that generates an acid or a base upon irradiation with radiation include a radiation-sensitive acid generator or a radiation-sensitive base generator.

  The radiation-sensitive acid generator is a compound capable of releasing an acidic substance capable of curing (crosslinking) the silane compound component by irradiation with radiation such as ultraviolet rays. For example, trichloromethyl-s-triazines, diaryliodonium Salts, triarylsulfonium salts, quaternary ammonium salts, sulfonic acid esters and the like can be used. Of these, diaryl iodonium salts and triaryl sulfonium salts are preferred.

  Examples of the trichloromethyl-s-triazines include 2,4,6-tris (trichloromethyl) -s-triazine, 2-phenyl-4,6-bis (trichloromethyl) -s-triazine, and 2- (4 -Chlorophenyl) -4,6-bis (trichloromethyl) -s-triazine, 2- (3-chlorophenyl) -4,6-bis (trichloromethyl) -s-triazine, 2- (2-chlorophenyl) -4, Examples thereof include 6-bis (trichloromethyl) -s-triazine, 2- (4-methoxyphenyl) -4,6-bis (trichloromethyl) -s-triazine and the like.

  Next, the silane coupling agent can be used to improve the adhesion between the insulating film 60 formed from the radiation-sensitive composition of the present embodiment and the substrate 10.

  As such a silane coupling agent, a functional silane coupling agent is preferably used. For example, a silane coupling agent having a reactive substituent such as a carboxyl group, a methacryloyl group, a vinyl group, an isocyanate group, an epoxy group, or an amino group. Agents.

  Here, a silane coupling agent having an epoxy group is most preferable, among which γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, β-glycidoxyethyltrimethoxysilane, β-glycid Xylethylmethyldimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethylmethyldimethoxysilane, γ- (3,4-epoxycyclohexyl) propyltrimethoxysilane Γ- (3,4-epoxycyclohexyl) propylmethyldimethoxysilane is particularly preferred.

  The blending amount of such (C) silane coupling agent is usually 50 parts by weight or less, preferably 2 to 50 parts by weight, more preferably 5 to 30 parts by weight with respect to 100 parts by weight of component (A). .

  Further, the dehydrating agent that can be added to the radiation-sensitive composition of the present embodiment can convert water into a substance other than water by a chemical reaction, or can be trapped by physical adsorption or inclusion. It is a substance.

  By including a dehydrating agent in the radiation-sensitive composition of the present embodiment, the influence of moisture entering from the environment or moisture generated from the silane compound component by irradiation with radiation in the formation process of the insulating film 60 described later is reduced. Therefore, it is estimated that it contributes to the improvement of the radiation sensitivity of the composition.

  As such a dehydrating agent, at least one compound selected from the group consisting of carboxylic acid esters, acetals (including ketals), and carboxylic acid anhydrides can be preferably used.

  Furthermore, examples of the additive to the radiation-sensitive composition that is a raw material for the insulating film 60 include an acid diffusion controller, a sensitizer, and a surfactant.

  The acid diffusion control agent can be used when the above radiation sensitive acid generator is used, and controls the diffusion of acidic substances generated in the composition coating film by irradiating the radiation sensitive acid generator with radiation. And has the effect of suppressing the curing reaction in the non-exposed areas. By adding such an acid diffusion controller, a radiation-sensitive composition having an excellent pattern system can be obtained.

  Moreover, a sensitizer can be mix | blended in order to improve the sensitivity with respect to the radiation of the radiation sensitive composition of this embodiment.

  The radiation-sensitive composition for forming this insulating film 60 contains a silane compound and other additives as described above, but is usually prepared in a state dissolved or dispersed in a solvent. ,used.

  As the solvent that can be used for the preparation of this radiation-sensitive composition, those that uniformly dissolve or disperse each component of the radiation-sensitive composition and do not react with each component are preferably used, such as alcohol and ether. An organic solvent or the like can be used.

  Next, the details of a method for forming the insulating film 60 using a photolithography method using a radiation-sensitive composition containing a silane compound as a raw material will be described.

  In this film forming method, for example, a photolithography method is used on ITO as a patterned anode 20 by using a radiation sensitive composition containing a photosensitive silane compound as shown in FIG. Formed.

  That is, it is unnecessary by applying a radiation-sensitive resin composition containing a photosensitive silane compound with a predetermined film thickness, irradiating light through a photomask, photocuring the portion where the insulating film 60 is left, and developing. An insulating film can be formed at a predetermined position by dissolving and removing such a portion and then baking.

  More specifically, the insulating film 60 of the organic EL display device S1 can be formed using the radiation sensitive resin composition as a raw material, for example, as follows. FIG. 5 is a process diagram showing the forming method.

  First, as shown in FIG. 5A, a substrate 10 on which ITO as an anode 20 is patterned is prepared.

  Further, as shown in FIG. 5 (b), the radiation sensitive resin composition which is a raw material of the insulating film 60 is applied to the surface of the substrate 10, and the solvent is removed by pre-baking to thereby form the coating film 61. (Application process). As this coating method, for example, an appropriate method such as a spray method, a roll coating method, a spin coating method, or a bar coating method can be employed.

  Moreover, although the prebaking conditions vary depending on the type and blending ratio of each component, they are usually 30 to 200 ° C., more preferably 40 to 150 ° C., and heating is performed using a hot plate, oven, infrared rays, or the like. Can do. The film thickness after the pre-baking can be set to a desired value depending on the solid content concentration of the radiation-sensitive composition 61 and application conditions, and can be set to about 0.5 to 7 μm, for example.

  Next, as shown in FIG. 5C, the formed coating film 61 is irradiated with radiation UV through a photomask K1 having a predetermined pattern (exposure process).

Examples of the radiation used here include ultraviolet rays such as g-ray (wavelength 436 nm) and i-ray (wavelength 365 nm), far ultraviolet rays such as KrF excimer laser, X-rays such as synchrotron radiation, and charged particle beams such as electron beams. Can be mentioned. Of these, g-line and i-line are preferable. Energy of exposure generally 50~10,000J / m ^2, preferably 100~5,000J / m ^2.

  Moreover, it is preferable to perform heat processing (post-exposure baking (PEB)) after exposure. For the heating, an apparatus similar to the pre-bake can be used, and the conditions can be arbitrarily set. A preferred heating temperature is 30 to 150 ° C, more preferably 30 to 130 ° C.

  After irradiating with radiation, as shown in FIG. 5 (d), a coating film 61 having a desired pattern is obtained by developing with a developer to remove the coating film 61 on the irradiated portion of the radiation ( Development process).

  Examples of the developer used here include inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium oxalate, sodium metasuccinate and aqueous ammonia; primary amines such as ethylamine and n-propylamine. Secondary amines such as diethylamine and di-n-propylamine; tertiary amines such as triethylamine and methyldiethylamine; alcoholamines such as dimethylethanolamine and triethanolamine; tetramethylammonium hydroxide , Quaternary ammonium salts such as tetraethylammonium hydroxide and choline, pyrrole, piperidine, 1,8-diazabicyclo- (5.4.0) -7-undecene, 1,5-diazabicyclo- (4.3. 0) Cyclic amines such as 5-nonane were dissolved in water. Alkaline aqueous solution is preferably used.

  In addition, an appropriate amount of a water-soluble organic solvent, for example, an alcohol such as methanol or ethanol, or a surfactant can be added to the developer. Furthermore, various organic solvents that dissolve the radiation-sensitive composition can also be used as the developer.

  As a developing method, an appropriate method such as a liquid piling method, a dipping method, a rocking dipping method, or the like can be used. After the development process, the patterned coating film 61 may be rinsed, for example, by washing with running water.

  Thereafter, as shown in FIG. 5E, the target insulating film 60 can be formed by subjecting the coating film 61 to a heat treatment using a heating device such as a hot plate oven (baking step). ).

  The heating temperature in this heat treatment can be, for example, 150 to 400 ° C., and the heating time is 5 to 30 minutes when heating on a hot plate, and 30 to 90 when heating in an oven. Can be minutes. The film thickness of the insulating film 60 can be set to an appropriate value based on the composition of the composition, the structure of the target organic EL display device, etc., and can be set to 0.5 to 7 μm, for example.

  Conventionally known insulating film materials are mainly composed of organic synthetic polymers, and have limited heat resistance. For this reason, the heating temperature in the firing step cannot be sufficiently increased, for example, heat treatment at a temperature of 250 ° C. or less is forced, and moisture present in the material can be sufficiently removed in the firing step. There wasn't.

  Therefore, when such a material is used for the insulating film 60 of the organic EL display device, moisture remaining in the insulating film 60 gradually enters the organic film 30 and inhibits the light emission characteristics of the organic EL display device. It was a cause.

  Since the radiation sensitive composition of this embodiment is mainly composed of a silane compound having high heat resistance, a temperature exceeding 250 ° C., for example, a high temperature of 300 ° C. to 400 ° C. can be employed in the heating step. Therefore, the moisture remaining in the insulating film 60 can be made substantially zero, which is considered to contribute to the long life of the organic EL display device.

  After forming the insulating film 60 in this way, as shown in FIG. 5F, the partition wall 70 is formed by photolithography, the organic film 30 is deposited, and the cathode 40 is formed. The organic EL display device S1 is completed by sealing with.

[Effects]
By the way, according to the present embodiment, the substrate 10 includes the plurality of pixels 50 formed by laminating the lower electrode 20, the organic film 30 including the light emitting layer 33, and the upper electrode 40. In the organic EL display device S1 having the insulating film 60 disposed between the pixels 50, the organic EL display device S1 having the following characteristic points is provided.

  The insulating film 60 contains at least one compound selected from the group consisting of the silane compound represented by the chemical formula (1), a hydrolyzate thereof, and a condensate of the hydrolyzate.

  The pixel 50 is in a light emitting state when a forward bias voltage is applied. Further, when the electric field Ya is Vr and the thickness of the organic film 30 is Dy, the following equation (2) The reverse bias voltage such that the electric field Ya is 1.5 MV / cm or more can be applied to the pixel 50.

(Equation 3)
Ya = Vr / Dy (2)
According to the organic EL display device S1 of the present embodiment, which is characterized by these points, the heat resistance temperature is approximately 540 ° C. as the insulating film 60 with respect to the problem that the insulating film is thermally deformed and the upper and lower electrodes are short-circuited. If a certain silane compound is used, a short circuit caused by thermal deformation of the insulating film can be prevented in practical use of the organic EL display device. The heat-resistant temperature of this silane compound is the same as the melting point of the upper electrode 40 made of general Al or the like.

  Further, in the present embodiment, a reverse bias voltage that is 1.5 MV / cm or more larger than the conventional reverse bias voltage can be applied to the pixel 50. This has been found experimentally.

  Specific experimental results are shown in FIG. FIG. 6 shows the relationship between the panel defect rate (unit:%) due to the short circuit between the upper and lower electrodes 20 and 40 and the electric field Ya (= Vr / Dy, unit: MV / cm) applied to the insulating film 60 when the reverse bias voltage is applied. It is a figure which shows the result of having investigated.

  Here, the definition of the panel defect rate is as follows. A dot matrix panel having 256 × 64 pixels is used for driving, and if a line defect due to a short circuit between the upper and lower electrodes occurs even at one location in the panel, it is determined as defective. Then, the panel is driven with a durability time of 500 hours, and the number of defects generated within 500 hours is investigated. The panel defect rate is defined as the number of panel defects / the number of durability test panels.

  As can be seen from FIG. 6, when a reverse bias voltage of 1.5 MV / cm or more is applied to the pixel 50, the cathode that is the upper electrode by Joule heat of the reverse bias voltage immediately above the defective portion of the insulating film 60. 40 can be skipped and the opening of the electrode can be realized. Therefore, the upper and lower electrodes 20 and 40 are not short-circuited through the defective portion of the insulating film 60.

  As described above, according to the present embodiment, in the organic EL display device having the insulating film 60 in the non-light emitting region between the pixels 50, it is possible to prevent the upper and lower electrodes 20 and 40 from being short-circuited as much as possible when the reverse bias voltage is applied. it can.

  In the present embodiment, the insulating film 60 is made of an organic polymer material whose weight change at 540 ° C. is within 10%, and the pixel 50 is in a light emitting state when a forward bias voltage is applied. Further, a reverse bias voltage such that the electric field (electric field strength) Ya is 1.5 MV / cm or more can be applied to the pixel 50. A device S1 is provided.

  As described above, when the insulating film material is a heat resistant material, a short circuit caused by thermal deformation of the insulating film can be prevented. This is because when the upper electrode reaches a temperature close to the melting point (500 ° C. or more) due to Joule heat, the insulating film retains its shape, so that the upper and lower electrodes can be prevented from being short-circuited due to thermal deformation of the insulating film.

  In particular, as a definition of heat resistance, in the case of organic polymers, since a clear melting point cannot be defined, the present inventor has derived a new heat resistance index. That is, the temperature at which the weight loss rate is 10% in TGA (thermogravimetric analysis) is the heat resistant temperature.

  In the insulating film 60, if the temperature at which the weight reduction rate is 10% is 540 ° C. or higher, the insulating film 60 retains its shape, and the upper and lower electrodes 20, 40 are short-circuited due to thermal deformation of the insulating film. It was experimentally found that this can be prevented.

  Specific experimental results are shown in FIG. FIG. 7 is a diagram showing the results of investigating the relationship between the panel defect rate and the heat-resistant temperature (unit: ° C.) of the insulating film 60. In FIG. 7, the electric field Ya (= Vr / Dy) applied to the insulating film 60 when the reverse bias voltage is applied was investigated as 1.5 MV / cm.

  Further, the heat resistant temperature, that is, the temperature at which the weight reduction rate becomes 10% in TGA (thermogravimetric analysis) is about 300 ° C. for phenol resin, about 380 ° C. for photosensitive polyimide, and 540 ° C. for the silane compound of this embodiment. It is. In FIG. 7, these materials are used as the insulating film 60 to be investigated.

  As can be seen from FIG. 7, in the insulating film 60, if the temperature at which the weight reduction rate is 10% is 540 ° C. or higher, the insulating film 60 retains its shape, and the upper and lower electrodes are caused by thermal deformation of the insulating film. It turns out that the short circuit of 20 and 40 can be prevented. This is particularly effective when the upper electrode 40 is Al.

  Further, when the insulating film 60 having a temperature at which the weight reduction rate is 10% is 540 ° C. or higher is used, a reverse bias voltage of 1.5 MV / cm or higher is applied to the pixel 50. For example, the upper electrode 40 can be skipped by the Joule heat of the reverse bias voltage in the defective portion of the insulating film 60, and the opening can be realized.

  As described above, in the organic EL display device having the insulating film 60 in the non-light emitting region between the pixels 50 even when the insulating film 60 having a temperature at which the weight reduction rate is 10% is 540 ° C. or more is used. A short circuit between the upper and lower electrodes 20 and 40 when a reverse bias voltage is applied can be prevented as much as possible.

  Further, in the organic EL display device S1 of the present embodiment, the insulating film 60 is preferably made of a material that becomes an aggregated state instead of a porous state at the time of dielectric breakdown.

  Here, the porous state is one in which many voids are generated at the time of dielectric breakdown and becomes a network, and is easily deformed. Moreover, the aggregation state is a state in which a bulk state is maintained at the time of dielectric breakdown.

  Since the breakdown shape of the insulating film 60 is not porous but is in an agglomerated state, it is possible to prevent the upper electrode 40 from being involved due to thermal deformation of the insulating film 60 and to easily prevent the upper and lower electrodes 20 and 40 from being short-circuited. Become.

  In addition, as described above, in the present embodiment, although the pixel breakdown voltage is less than or equal to the pixel, an extremely high reverse bias voltage with an electric field Ya of 1.5 MV / cm or more is applied to the pixel 50 to add to the organic film 30. Including the insulating film 60, the upper electrode 40 in the defective portion is scattered to open the electrode.

  In order to scatter the upper electrode 40 as described above, a high electric field is required. In other words, it means that a high current is required to scatter the upper electrode 40. This is because scattering of the upper electrode 40 is caused by the organic film 30 due to Joule heat.

  Here, as described above, the voltage application to the pixel 50 is applied from an external drive circuit. However, circuit wiring resistance and panel wiring resistance exist between the pixel 50 and the driving circuit. If these wiring resistances are large, the electric field Ya is 1.5 MV / cm or more in the output of the circuit, but the pixel 50 has a smaller electric field, and the above-described opening cannot be realized. There is a fear.

  Therefore, the current supplied to the pixel 50 when the reverse bias voltage is applied, that is, the reverse bias current supply capability (maximum supply current value) of the drive circuit is used as the set value taking such wiring resistance into consideration.

  The reverse bias current supply capability of the drive circuit is obtained by dividing the output voltage of the drive circuit by (circuit wiring resistance + panel wiring resistance) in the current path including the organic EL display device S1 when the reverse bias voltage is applied. It is a value and represents the current that flows when the upper and lower electrodes 20, 40 are short-circuited.

  Then, the present inventor investigated the extent to which the reverse bias current supply capability of the drive circuit is sufficient to determine whether the above open circuit is possible. The result is shown in FIG. FIG. 8 is a diagram showing the results of investigating the relationship between the panel defect rate and the reverse bias current supply capability (unit: mA).

  As can be seen from FIG. 8, when the reverse bias current supply capability is 40 mA or more, that is, when a current of 40 mA or more is supplied to the pixel 50 when the reverse bias is applied, the reverse bias voltage is applied to the defective portion of the insulating film 60. The upper electrode 40 can be skipped by the Joule heat, and the opening is appropriately performed. Therefore, the upper and lower electrodes 20 and 40 are not short-circuited through the defective portion of the insulating film 60.

(Other embodiments)
In the embodiment described above, the insulating film 60 is defined as described above, and a reverse bias voltage is applied to the pixel 50 such that the electric field Ya is 1.5 MV / cm or more. Although display failure is prevented from occurring, such reverse bias voltage may be applied before shipment.

  That is, the same reverse bias voltage may be applied in an inspection process as a part of the manufacturing method. Thereby, an organic EL display device having high reliability can be shipped. Here, screening is preferably performed at a high temperature, for example, a high temperature of about 90 ° C. Further, it is preferable to set a reverse bias voltage higher than that of actual driving.

  Further, supplying a current of 40 mA or more to the pixel 50 when a reverse bias is applied can be easily realized by adjusting the wiring resistance in the drive circuit. For example, as the configuration of the drive circuit, the supply current can be controlled by adjusting the on-resistance of the reverse bias application driver.

1 is a schematic plan view of an organic EL display device according to an embodiment of the present invention. It is a schematic sectional drawing in alignment with the AA in FIG. It is a schematic sectional drawing in alignment with the BB line in FIG. It is a figure which shows an example of the structure of the silane compound used for an insulating film. It is process drawing which shows the formation method of the insulating film which used the radiation sensitive resin composition for the raw material. It is a figure which shows the result of having investigated the relationship between the short circuit rate of an up-and-down electrode, and the electric field Ya (= Vr / Dy) added to an insulating film at the time of reverse bias voltage application. It is a figure which shows the result of having investigated the relationship between the short circuit rate of an upper and lower electrode, and the heat-resistant temperature of an insulating film. It is a figure which shows the result of having investigated the relationship between the short circuit rate of an up-and-down electrode, and the maximum supply current value.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Substrate, 20 ... Anode as lower electrode, 30 ... Organic film, 33 ... Light emitting layer, 40 ... Cathode as upper electrode, 50 ... Pixel, 60 ... Insulating film.

Claims (5)

A substrate (10) has a plurality of pixels (50) in which a lower electrode (20), an organic film (30) including a light emitting layer (33), and an upper electrode (40) are stacked, and the substrate ( 10) In an organic EL display device having an insulating film (60) disposed between each of the pixels (50) above,
The insulating film (60) contains at least one compound selected from the group consisting of a silane compound represented by the following chemical formula (1), a hydrolyzate thereof, and a condensate of the hydrolyzate.
(Chemical formula 1)
(R1) _p Si (X) _4-p (1)
In the chemical formula (1), R1 is a non-hydrolyzable organic group having 1 to 12 carbon atoms, X is a hydrolyzable group, and p is an integer of 0 to 3,
The pixel (50) is in a light emitting state when a forward bias voltage is applied,
Further, the electric field Ya has the following formula (2), where Vr is the reverse bias voltage and Dy is the thickness of the organic film (30):
(Equation 1)
Ya = Vr / Dy (2)
It is represented by
An organic EL display device, wherein a reverse bias voltage in which the electric field Ya is 1.5 MV / cm or more can be applied to the pixel (50). A substrate (10) has a plurality of pixels (50) in which a lower electrode (20), an organic film (30) including a light emitting layer (33), and an upper electrode (40) are stacked, and the substrate ( 10) In an organic EL display device having an insulating film (60) disposed between each of the pixels (50) above,
The insulating film (60) is made of an organic polymer material whose weight change at 540 ° C. is within 10%,
The pixel (50) is in a light emitting state when a forward bias voltage is applied,
Further, the electric field Ya has the following formula (2), where Vr is the reverse bias voltage and Dy is the thickness of the organic film (30):
(Equation 2)
Ya = Vr / Dy (2)
It is represented by
An organic EL display device, wherein a reverse bias voltage in which the electric field Ya is 1.5 MV / cm or more can be applied to the pixel (50). The plurality of pixels (50) are arranged in a grid formed by the lower electrode (20) having a stripe shape and the upper electrode (40) having a stripe shape perpendicular to the lower electrode (20).
The insulating film (60) is disposed between the lower electrodes (20) between the pixels (50) and on the portion of the lower electrode (20) located between the upper electrodes (40). The organic EL display device according to claim 1, wherein the organic EL display device is an organic EL display device. The organic EL display device according to any one of claims 1 to 3, wherein the insulating film (60) is made of a material that becomes an aggregated state instead of a porous state at the time of dielectric breakdown. 5. The organic EL display device according to claim 1, wherein a current of 40 mA or more is supplied to the pixel (50) when a reverse bias is applied. 6.

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