JP2009026669A - Electro-optical device and electronic equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electro-optical device capable of suppressing irregularities in emitting characteristics, and to provide an electronic equipment equipped with the same. <P>SOLUTION: An organic EL device 11 has a glass substrate, a circuit-device layer, a light-emitting element layer, and a negative electrode. The light-emitting element layer consists of a function layer formed on a pixel electrode 32, and a bank 34 partitioning the function layer. The bank 34 has a first lower bank 41, a second lower bank 42, and an upper bank 43. Further, the bank 34 is formed in a track having emitting regions 12 with different aspect ratios and regions of circular arcs 44 formed at the short side of the emitting region 12. The first lower bank 41, the second lower bank 42, and the upper bank 43 are formed stepwise in the region of each circular arc 44. The first lower bank 41 and the upper bank 43 are formed stepwise in the region of the line 45. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an electro-optical device and an electronic apparatus in which a functional layer is formed in an opening of a bank.

  One of the electro-optical devices described above is an organic EL (electroluminescence) device. The organic EL device has a structure in which a light emitting layer made of a light emitting material is sandwiched between an anode and a cathode. As a manufacturing method of the organic EL device, for example, the method includes forming a light emitting material into an ink and discharging the ink to a light emitting region on a substrate using an ink jet method. In the light emitting region on the substrate, for example, a bank made of an organic material (for example, acrylic resin) for filling ink in a predetermined portion is formed.

  In the bank, in a region corresponding to the light emitting region, for example, a track-shaped opening having a long side and a short side is formed. The inside of the arc formed on the short side has a problem that ink wettability is poor and ink is difficult to fill. This causes variations in the thickness of the ink ejected to the opening, and as a result, uniform light emission cannot be obtained.

  Thus, for example, as described in Patent Document 1, an inorganic material (for example, a silicon oxide film or a silicon nitride film) for facilitating filling of the opening of the bank with two inks is provided below the acrylic resin bank. A method is known in which a layer (hereinafter referred to as a “two-layer bank”) is exposed stepwise to improve ink wettability in a circular arc region and to make the film thickness uniform in the bank. ing.

JP 2005-158494 A

  However, as the light emitting area becomes smaller with higher definition, it is necessary to make the opening of the bank smaller, and in particular, the amount of overhang of the two-layer bank exposed on the narrow side (long side) of the opening Depending on the accuracy, the thickness of the ejected ink varies. As a result, there is a problem that light cannot be emitted uniformly (the light emission characteristics vary). In addition, by forming the two-layer bank in a stepped manner, there is a problem that the amount of protrusion to the light emitting region side is increased, and in particular, the aperture ratio on the narrow side of the opening portion is lowered.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

  Application Example 1 An electro-optical device according to this application example is an electro-optical device having a plurality of light emitting regions, and is formed on a substrate and a region on the substrate excluding the light emitting region. A bank formed so as to surround the light emitting region, and a functional layer disposed in an opening surrounded by the bank, the bank including an upper layer bank and a plurality of layers having higher wettability than the upper layer bank. A lower layer bank, and the lower layer bank has a smaller number of layers of the lower layer bank exposed in the second region than a number of layers of the lower layer bank exposed in the first region in the opening. And

  According to this configuration, since at least the lower layer bank is formed in the first region in the opening, the liquid can be made to conform to the lower layer bank of the first region, and the first region can be filled with the liquid. . Therefore, variation in the thickness of the liquid in the light emitting region can be suppressed, and when the functional layer is formed from the liquid, it is possible to obtain a functional layer in which the variation in thickness is suppressed. As a result, light can be emitted uniformly in the light emitting region. Furthermore, since the number of layers of the lower layer bank exposed in the second region is small, it is possible to suppress variations in the thickness of the liquid due to the amount of protrusion at the end of the lower layer bank. In addition, the opening area of the second region can be increased.

  Application Example 2 In the electro-optical device according to the application example, the opening has a corner when viewed from the normal direction, and the first region includes a part of the corner of the opening. It is preferable that

  According to this configuration, since at least the lower layer bank is formed in a region including a part of the corner, it becomes possible to allow the liquid to become familiar with the lower layer bank in this region, and a part of the corner that is relatively difficult to fill with liquid. The region containing can be filled with liquid.

  Application Example 3 In the electro-optical device according to the application example, the opening has an arc when viewed from the normal direction, and the first region includes a part of the arc in the opening. It is preferable that

  According to this configuration, since at least the lower layer bank is formed in a region including a part of the arc (such as a part inside the arc), it becomes possible to adjust the liquid to the lower layer bank in this region. The liquid can be filled into a partial region of the arc that is relatively difficult to fill.

  Application Example 4 In the electro-optical device according to the application example, the opening has a short side and a long side when viewed from the normal direction, and the first region includes the short side of the opening. It is preferable that the second region is a region on the long side of the opening.

  According to this configuration, since at least the lower layer bank is formed in the region on the short side, the width of the opening is narrow compared to the region on the long side, and the short side (first region) is relatively difficult to fill with liquid. ) Can be filled with liquid. In addition, since the number of lower-layer banks exposed in the region on the long side (second region) is small, the aperture ratio in the narrow direction sandwiched between the long sides can be increased.

  Application Example 5 In the electro-optical device according to the application example, the lower layer bank includes a first lower layer bank and a second lower layer bank from the substrate side, and a contact angle with respect to the liquid of the second lower layer bank is The contact angle with respect to the liquid of the first lower layer bank is preferably small.

  According to this configuration, since the second lower layer bank having a liquid contact angle smaller than that of the first lower layer bank is formed in the first region, the liquid filling property of the first region can be improved.

  Application Example 6 In the electro-optical device according to the application example, it is preferable that the first lower layer bank is a silicon oxide film, and the second lower layer bank is a silicon nitride film.

  According to this configuration, since the silicon oxide film and the silicon nitride film having higher wettability than the silicon oxide film, by selecting and forming the lower bank of two film qualities, the liquid filling property, Insulation properties, suitability for surface treatment, and the like can be considered.

  Application Example 7 In the electro-optical device according to the application example, it is preferable that the first region is formed so that the second lower layer bank is exposed.

  According to this configuration, since the second lower layer bank having high wettability is formed in the first region that is relatively difficult to fill with liquid, the first region can be filled with liquid.

  Application Example 8 In the electro-optical device according to the application example, the first region is formed by exposing the first lower layer bank and the second lower layer bank, and the second region is the first lower layer bank. Alternatively, it is preferable that either one of the second lower layer banks is exposed.

  According to this configuration, since the two-layer lower layer bank is formed in the first region that is relatively difficult to fill with liquid, the first region can be filled with liquid. On the other hand, when only the first lower layer bank is formed in the second region, it is possible to prevent a lot of wasted liquid on the second lower layer bank as in the case where the second lower layer bank having high wettability is formed. be able to. Therefore, the liquid can be used efficiently. Further, when only the second lower layer bank is formed in the second region, it becomes possible to make the liquid more familiar with the second lower layer bank, and the flatness of the liquid can be improved in the light emitting region.

  Application Example 9 An electro-optical device according to this application example is an electro-optical device having a plurality of light emitting regions, and is formed on a substrate and a region on the substrate excluding the light emitting region. A bank formed to surround the light emitting region, and a functional layer disposed in an opening surrounded by the bank, the bank including an upper layer bank and a lower layer bank having higher wettability than the upper layer bank, The lower layer bank is exposed in the first region in the opening and is not exposed in the second region.

  According to this configuration, since the lower layer bank is exposed in the first region in the opening, the liquid can be made to conform to the lower layer bank of the first region, and the liquid can be filled in the first region. Therefore, variation in the thickness of the liquid in the light emitting region can be suppressed, and when the functional layer is formed from the liquid, it is possible to obtain a functional layer in which the variation in thickness is suppressed. As a result, light can be emitted uniformly in the light emitting region. Furthermore, since the lower layer bank is not exposed in the second region, it is possible to suppress variations in the thickness of the liquid due to the amount of protrusion at the end of the lower layer bank. In addition, the opening area of the second region can be increased.

  Application Example 10 In the electro-optical device according to the application example, a pixel electrode formed on one surface of the substrate corresponding to each of the plurality of light emitting regions, and the pixel electrode sandwiching the functional layer It is preferable that the functional layer has at least a light emitting layer.

  According to this configuration, for example, in an organic EL device having a pixel electrode and a common electrode arranged with a light emitting layer interposed therebetween, light can be emitted uniformly.

  Application Example 11 Electronic equipment according to this application example includes the above-described electro-optical device.

  According to this configuration, it is possible to obtain an electro-optical device that can improve the aperture ratio and emit light uniformly.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, embodiments of the invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 is a schematic cross-sectional view illustrating a partial structure of an organic EL device as an electro-optical device according to the first embodiment. FIG. 2 is a schematic diagram showing the bank structure at the stage where the bank is formed in the organic EL device. (A) is the schematic top view which looked at the organic electroluminescent apparatus from the upper direction. (B) is a schematic cross section along the AA section of the organic EL device shown in (a). (C) is a schematic cross section which follows the BB cross section of the organic electroluminescent apparatus shown to (a). In addition, FIG. 1 shows the cross-sectional positional relationship of each component, and the relative relationship is exaggerated. Hereinafter, the structure of the organic EL device will be described with reference to FIGS.

  As shown in FIG. 1, the organic EL device 11 emits light in a light emitting region 12, a substrate 13, a circuit element layer 14 formed on the substrate 13, and a light emitting element formed on the circuit element layer 14. The layer 15 and the cathode (common electrode) 16 formed on the light emitting element layer 15 are included. Examples of the substrate 13 include a glass substrate having translucency (hereinafter referred to as “glass substrate 13”).

In the circuit element layer 14, a base protective film 17 made of a silicon oxide film (SiO ₂ ) is formed on a glass substrate 13, and a TFT (Thin Film Transistor) element 18 is formed on the base protective film 17. Specifically, an island-shaped semiconductor film 19 made of a polysilicon film is formed on the base protective film 17. A source region 21 and a drain region 22 are formed in the semiconductor film 19 by introducing impurities. A portion where no impurity is introduced is a channel region 23.

Further, a transparent gate insulating film 24 made of a silicon oxide film or the like covering the base protective film 17 and the semiconductor film 19 is formed on the circuit element layer 14. On the gate insulating film 24, a gate electrode 25 (scanning line) made of aluminum (Al), molybdenum (Mo), tantalum (Ta), titanium (Ti), tungsten (W), or the like is formed. A transparent first interlayer insulating film 26 and second interlayer insulating film 27 are formed on the gate insulating film 24 and the gate electrode 25. The first interlayer insulating film 26 and the second interlayer insulating film 27 are composed of, for example, a silicon oxide film (SiO ₂ ), a titanium oxide film (TiO ₂ ), or the like. The gate electrode 25 is provided at a position corresponding to the channel region 23 of the semiconductor film 19.

  The source region 21 of the semiconductor film 19 is electrically connected to the signal line 29 formed on the first interlayer insulating film 26 through a contact hole 28 provided through the first interlayer insulating film 26 and the gate insulating film 24. Connected. On the other hand, the drain region 22 is formed on the second interlayer insulating film 27 through a contact hole 31 provided through the second interlayer insulating film 27, the first interlayer insulating film 26, and the gate insulating film 24. The pixel electrode 32 is electrically connected.

  The pixel electrode 32 is formed for each light emitting region 12. The pixel electrode 32 is made of a transparent ITO (Indium Tin Oxide) film, and has, for example, a substantially rectangular shape when viewed from the plane direction (see FIG. 2). In the circuit element layer 14, a storage capacitor and a switching transistor (not shown) are formed. In this manner, the driving transistor connected to each pixel electrode 32 is formed in the circuit element layer 14.

  The light emitting element layer 15 includes light emitting elements arranged in a matrix and is formed on the glass substrate 13. More specifically, the light emitting element layer 15 is mainly composed of a functional layer 33 formed on the pixel electrode 32 and a bank 34 that partitions the functional layer 33. On the functional layer 33, the cathode 16 is disposed. The pixel electrode 32, the functional layer 33, and the cathode 16 constitute a light emitting element.

  In the bank 34, for example, an opening 35 is formed in a track shape when viewed in plan (see FIG. 2A). More specifically, the opening 35 of the bank 34 has a light emitting region 12 having different aspect ratios and a region of an arc 44 as a first region formed on the short side (Y direction) of the light emitting region 12. Here, the region of the arc 44 refers to a region surrounded by the shape of the arc 44 in the opening 35. It is also referred to as an arc side region.

  The region of the arc 44 in the opening 35 is configured by laminating a first lower layer bank 41, a second lower layer bank 42, and an upper layer bank 43 from the glass substrate 13 side, stepwise while exposing the end portion. (See FIG. 2 (b)).

The first lower layer bank 41 is formed so as to run on the peripheral edge of the pixel electrode 32 in order to ensure insulation between adjacent pixel electrodes 32. That is, the pixel electrode 32 and the first lower layer bank 41 have a structure arranged so as to partially overlap in plan view. Examples of the material of the first lower layer bank 41 include a silicon oxide film (SiO ₂ ) that is an inorganic material.

  The second lower layer bank 42 is formed on the first lower layer bank 41 in order to further improve the wettability with the functional liquid (for example, the ink of the hole injection layer 51). As a material of the second lower layer bank 42, for example, a silicon nitride film (SiN) which is higher in wettability than a silicon oxide film, for example, is an inorganic material. Further, the silicon nitride film has a higher dielectric constant than the silicon oxide film.

  The upper layer bank 43 is used to partition the functional layer 33 and is formed on the first lower layer bank 41 layer and the second lower layer bank 42 layer. An example of the material of the upper layer bank 43 is an acrylic resin that is an organic material. The upper layer bank 43 is formed, for example, in a trapezoidal shape having an inclined surface when viewed in cross section.

  In the region of the straight line 45 (long side) as the second region in the opening 35, the first lower layer bank 41 and the upper layer bank 43 are stacked from the glass substrate 13 side in a stepped manner with the end portions exposed. It is configured (see FIG. 2C). Here, the region of the straight line 45 indicates a partial region related to the light emitting region 12 from the straight line portion in the opening 35. It is also referred to as a straight line region. The second lower layer bank 42 is not exposed in the region of the straight line portion. The materials of the first lower layer bank 41 and the upper layer bank 43 are the same as described above.

  As described above, the second lower layer bank 42 made of a silicon nitride film having high wettability is laminated together with the first lower layer bank 41 in the region of the arc 44 in the opening 35, so that the ink is particularly applied to the second lower layer bank 42. In this case, the ink can be filled in the region of the arc 44 that is relatively difficult to fill with ink.

  Further, since the region of the straight line 45 in the opening portion 35 is formed with only the first lower layer bank 41 having the lower layer bank 46 that is smaller than the region of the arc 44, the variation in the amount of protrusion of the lower layer bank 46 to the light emitting region 12 is reduced. Therefore, the thickness of the ink can be made uniform. Furthermore, since the lower layer bank 46 is composed of only one layer of the first lower layer bank 41, the aperture ratio of this region (region in the X direction) can be improved.

  Here, “high wettability” refers to a relatively small contact angle with ink. In other words, it can be said that the region on the arc side with high wettability (see FIG. 2A) can be easily filled with ink.

  The functional layer 33 is formed, for example, in a region where the hole injection layer 51 and the light emitting layer 52 as a functional layer are surrounded by the bank 34, that is, in the opening 35 (the light emitting region 12). The hole injection layer 51 is formed in a recess having the pixel electrode 32 as a bottom and banks 34 (41, 42, 43) as side walls (see FIGS. 2B and 2C).

  The hole injection layer 51 is composed of a conductive polymer layer containing a dopant in a conductive polymer material. Such a hole injection layer 51 can be composed of, for example, 3,4-polyethylenedioxythiophene (PEDOT-PSS) containing polystyrene sulfonic acid as a dopant.

  Due to the presence of the second lower layer bank 42 formed in the region of the arc 44, for example, the functional liquid discharged when forming the hole injection layer 51 is likely to spread and spread inside the arc 44 in the opening 35 ( Easier to fill). Therefore, the hole injection layer 51 can be easily formed in the bank 34, and the thickness of the hole injection layer 51 can be made uniform.

  The light emitting layer 52 is a layer of an organic light emitting material that exhibits an electroluminescence phenomenon, and is formed on the hole injection layer 51.

  The cathode 16 is formed on the light emitting layer 52 and the upper layer bank 43. In other words, the cathode 16 is formed on the opposite side of the pixel electrode 32 with the light emitting layer 52 interposed therebetween. The cathode 16 is, for example, a laminated body of calcium (Ca) and aluminum (Al). On the cathode 16, a sealing member (not shown) made of resin or the like for preventing water and oxygen from entering is laminated. The light emitting element layer 15 and the cathode 16 constitute a display element 53.

  As described above, the light emitting layer 52 described above is a layer of an organic light emitting material that exhibits an electroluminescence phenomenon. By applying a voltage between the pixel electrode 32 and the cathode 16, holes are injected from the hole injection layer 51 and electrons are injected from the cathode 16 into the light emitting layer 52. The light emitting layer 52 emits light when they are combined.

  In the organic EL device 11, for example, light emitted from the functional layer 33 to the glass substrate 13 side is transmitted through the circuit element layer 14 and the glass substrate 13 and emitted to the lower side of the glass substrate 13. The light emitted from the opposite side of the glass substrate 13 is reflected by the cathode 16, passes through the circuit element layer 14 and the glass substrate 13, and is emitted to the lower side of the glass substrate 13. Note that by using a transparent material for the cathode 16, light emitted from the cathode 16 side can be emitted.

  FIG. 3 is a process diagram illustrating a method for manufacturing an organic EL device. Hereinafter, a method for manufacturing the organic EL device will be described with reference to FIGS.

  As shown in FIG. 3, in the method for manufacturing the organic EL device 11, a bank is formed by steps S1 to S6, and an organic EL element is formed by steps S11 to S16. First, in step S1, the circuit element layer 14 is formed on the glass substrate 13 using a known film forming technique. In step S <b> 2, the pixel electrode 32 made of ITO is formed on the circuit element layer 14.

In step S <b> 3, the first lower layer bank 41 is formed on the circuit element layer 14 and the pixel electrode 32. Specifically, first, a first lower bank layer made of, for example, silicon oxide (SiO ₂ ), which is a material of the first lower bank 41, is formed on the circuit element layer 14 and the pixel electrode 32 by a CVD (Chemical Vapor Deposition) method or the like. It is formed so as to cover the top. Next, an opening 41a (see FIG. 1) is formed in a region corresponding to the light emitting region 12 in the first lower bank layer by using a photolithography technique and an etching technique.

  In step S <b> 4, the second lower layer bank 42 is formed on the first lower layer bank 41. Specifically, a silicon nitride film for forming the second lower layer bank 42 is laminated on the glass substrate 13 including the first lower layer bank 41. As a method of laminating, for example, a vapor deposition method is exemplified. Next, using the photolithography technique and the etching technique, the second lower layer bank 42 is patterned so that only the arc-side region in the opening 35 is exposed.

  In step S <b> 5, the upper layer bank 43 is formed on the second lower layer bank 42. Specifically, an acrylic resin for forming the upper layer bank 43 is laminated on the glass substrate 13 including the first lower layer bank 41 and the second lower layer bank 42. As a method of laminating, for example, a vapor deposition method is exemplified. Next, an opening 43a (see FIG. 1) is formed in a region corresponding to the light emitting region 12 by using a photolithography technique and an etching technique.

  As described above, the first lower layer bank 41 and the second lower layer bank 42 are exposed stepwise below the upper layer bank 43 in the region of the arc 44 in the opening 35. On the other hand, only the first lower layer bank 41 is exposed below the upper layer bank 43 in the region of the straight line 45 in the opening 35.

In step S6, the bank 34 is subjected to plasma processing. Specifically, the first lower layer bank 41 and the second lower layer bank 42 are subjected to, for example, oxygen plasma treatment using oxygen (O ₂ ) gas. On the other hand, for example, carbon tetrafluoride (CF ₄ ) plasma treatment using tetrafluoromethane is performed on the upper layer bank 43.

  More specifically, the oxygen plasma treatment to the first lower layer bank 41 and the second lower layer bank 42 is performed, for example, with a plasma power of 100 kW to 800 kW, an oxygen gas flow rate of 50 ml / min to 100 ml / min, and a plate conveyance speed of 0.5 mm / sec to 10 mm. / Sec and the substrate temperature of 70 ° C. to 90 ° C. makes it possible to make the first lower layer bank 41 and the second lower layer bank 42 lyophilic (low liquid repellency).

  On the other hand, the carbon tetrafluoride plasma treatment for the upper layer bank 43 includes, for example, a plasma power of 100 kW to 800 kW, a tetrafluoromethane gas flow rate of 50 ml / min to 100 ml / min, a substrate transfer speed of 0.5 mm / sec to 10 mm / sec, and a substrate temperature. By processing under conditions of 70 ° C. to 90 ° C., the upper bank 43 can be made liquid repellent (high liquid repellency).

  As described above, the bank 34 having the second lower layer bank 42 having an ink contact angle of 30 ° and the upper layer bank 43 having an ink contact angle of 90 ° is completed. Since the second lower layer bank 42 is formed in the area of the arc 44, the ink can be wetted and spread in the area of the arc 44. On the other hand, since the contact angle of the upper layer bank 43 is large, it is possible to prevent the ink from overflowing from the region of the straight line portion.

  In the subsequent step S11, a functional liquid containing the material of the hole injection layer 51 is discharged onto the light emitting region 12 surrounded by the bank 34 on the pixel electrode 32 by a droplet discharge method (for example, an ink jet method). Specifically, the liquid droplets of the functional liquid are discharged toward the concave portion having the pixel electrode 32 as the bottom and the bank 34 (41, 42, 43) as the side wall. As the functional liquid of the hole injection layer 51, for example, a PEDOT-PSS dispersion liquid can be used. As an example of the PEDOT-PSS dispersion, a PEDOT / PSS weight ratio of 1:10, a solid content concentration of 0.5%, a diethylene glycol content of 50%, and a remaining amount of pure water is used. be able to.

  In step S12, the functional liquid is dried to form the hole injection layer 51. Specifically, the hole injection layer 51 is formed in the bank 34 by drying or baking the functional liquid in a high temperature environment to evaporate the solvent and solidify PEDOT-PSS contained in the functional liquid. As a drying condition, for example, the glass substrate 13 is allowed to stand for 10 minutes in an environment of 200 ° C. As a result, a 50 nm hole injection layer 51 is formed.

  In step S13, the functional liquid containing the material of the light emitting layer 52 is discharged onto the hole injection layer 51 by a droplet discharge method. As the functional liquid of the light emitting layer 52, for example, a liquid containing a red fluorescent material at a solid content concentration of 0.8% and using cyclohexylbenzene as a solvent can be used.

  As described above, since the first lower layer bank 41 and the second lower layer bank 42 with high wettability are formed in a stepped manner in the region of the arc 44 of the opening 35, the ink is particularly adapted to the second lower layer bank 42. This makes it possible to fill the region of the arc 44 that is relatively difficult to fill (region on the short side) with ink. In addition, it is possible to prevent the ink from retreating when the ink is dried. Thereby, it can suppress that the thickness of the light emitting layer 52 in the bank 34 becomes non-uniform | heterogenous. In addition, since the region inside the arc 44 is a region away from the light emitting region 12, even if two layers of the first lower layer bank 41 and the second lower layer bank 42 are formed, the aperture ratio is not lowered.

  In step S14, the functional liquid is dried to form the light emitting layer 52. Specifically, the light emitting layer 52 is formed by drying or baking the functional liquid in a high temperature environment to evaporate the solvent and solidify the red fluorescent material contained in the functional liquid. As a condition for drying, for example, the glass substrate 13 is allowed to stand for 1 hour in an environment of 100 ° C. The film thickness of the formed light emitting layer 52 is, for example, 100 nm. Since the light emitting layer 52 thus formed has a larger area than the hole injection layer 51, a relatively flat region of the light emitting layer 52 can be used for light emission.

  In step S15, the cathode 16 is formed by laminating a calcium film and an aluminum film in this order, for example, by vapor deposition on substantially the entire glass substrate 13 on which the light emitting layer 52 is formed. The formed calcium film is, for example, 5 nm. The formed aluminum film is, for example, 300 nm.

  In step S16, sealing is performed on the cathode 16 using, for example, an adhesive and a glass substrate to form an organic EL element, and the organic EL device 11 is completed.

  FIG. 4 is a schematic diagram illustrating a mobile phone as an example of an electronic apparatus including the organic EL device described above. Hereinafter, a mobile phone including the organic EL device will be described with reference to FIG.

  As shown in FIG. 4, the mobile phone 61 has a display unit 62 and operation buttons 63. The display unit 62 can perform high-quality display such as uniform light emission by the organic EL device 11 incorporated therein. The organic EL device 11 described above can be used in various electronic devices such as a mobile computer, a digital camera, a digital video camera, an in-vehicle device, and an audio device in addition to the mobile phone 61.

  As described above in detail, according to the first embodiment, the following effects can be obtained.

  (1) According to the first embodiment, the second lower layer bank 42 made of a silicon nitride film having high wettability is formed in addition to the first lower layer bank 41 in the region of the arc 44 that is difficult to fill. When ink is ejected into the portion 35, it is possible to wet and spread the ink in the region of the arc 44. Therefore, the thickness of the ink in the opening 35 can be made uniform, and as a result, the light can be emitted uniformly.

  (2) According to the first embodiment, since only the first lower layer bank 41 is formed in the region of the straight line 45, as in the case of forming two lower layer banks 46, the light emitting region 12 side of the lower layer bank 46. It is possible to suppress the occurrence of variations in film thickness due to the amount of overhang. Therefore, the film thickness can be made uniform, and as a result, the light can be emitted uniformly. Furthermore, since the lower layer bank 46 is composed of only one layer of the first lower layer bank 41, the aperture ratio of the region (X direction) sandwiched between the narrow straight lines 45 can be improved. In addition, the first lower layer bank 41 is composed of a silicon oxide film that has low wettability compared to the silicon nitride film, but has good wettability with ink. Can be filled.

  (3) According to the first embodiment, since the lower layer bank 46 in the region of the straight line 45 is composed of one layer, the opening width of this region (X direction) is widened. Accordingly, when ink is ejected, the ink is widely spread, and it is possible to prevent the ink from overflowing from the region of the straight line portion.

(Second Embodiment)
FIG. 5 is a schematic diagram illustrating the structure of the bank according to the second embodiment. (A) is the schematic top view which looked at the bank from the upper direction. (B) is a schematic cross section which follows the AA cross section of the bank shown to (a). (C) is a schematic cross section which follows the BB cross section of the bank shown to (a). Hereinafter, the bank structure will be described with reference to FIG. The bank structure of the second embodiment is such that the first lower layer bank is formed below the upper layer bank in the arc side region, and the portion where the lower layer bank is not formed in the straight line region is the first embodiment. Is different. Hereinafter, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted or simplified here.

  As shown in FIG. 5, the region of the arc 44 in the opening 35 is configured by stacking a first lower layer bank 41 and an upper layer bank 43 in a stepped manner from the glass substrate 13 side. In the region of the straight line 45 in the opening 35, only the upper layer bank 43 is formed.

  As described above, the first lower layer bank 41 is formed in the region of the arc 44 in the opening 35, so that the wettability is lower than that of the silicon nitride film, but the ink is adapted to the first lower layer bank 41. Thus, the ink can be filled in the region of the arc 44 that is relatively difficult to fill with ink.

  As described above in detail, according to the second embodiment, in addition to the effect (1) of the first embodiment described above, the following effects can be obtained.

  (4) According to the second embodiment, in the area of the straight line 45 in the opening 35, only the upper layer bank 43 is formed, and the lower layer bank 46 is not formed. Therefore, the aperture ratio of this area (area in the X direction) Can be improved. Further, since the opening 35 in the region of the straight line 45 is widened, when ink is ejected, the ink is accumulated in a wide range, and the ink is more unlikely to overflow. In addition, as described above, the area of the arc 44 can be filled with ink.

(Third embodiment)
FIG. 6 is a schematic diagram showing the structure of the bank according to the third embodiment. (A) is the schematic top view which looked at the bank from the upper direction. (B) is a schematic cross section which follows the AA cross section of the bank shown to (a). (C) is a schematic cross section which follows the BB cross section of the bank shown to (a). Hereinafter, the bank structure will be described with reference to FIG. Note that the bank structure of the third embodiment differs from that of the first embodiment in that only the second lower layer bank is formed below the upper layer bank in the region of the straight line portion. Hereinafter, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted or simplified here.

  As shown in FIG. 6, the region of the arc 44 in the opening 35 is configured by laminating a first lower layer bank 41, a second lower layer bank 42, and an upper layer bank 43 in a step shape from the glass substrate 13 side.

  In the region of the straight line 45 in the opening 35, the second lower layer bank 42 and the upper layer bank 43 are formed from the glass substrate 13 side. The second lower layer bank 42 is formed so as to run over the peripheral edge of the pixel electrode 32 in order to ensure the insulation of the pixel electrode 32.

  Thus, in addition to the first lower layer bank 41, the second lower layer bank 42 is formed in the region of the arc 44 in the opening 35, so that it is possible to make the ink particularly accustomed to the second lower layer bank 42. Ink can be filled in the region of the arc 44 that is relatively difficult to fill with ink.

  As described above in detail, according to the third embodiment, in addition to the effect (1) of the first embodiment described above, the following effects can be obtained.

  (5) According to the third embodiment, since the second lower layer bank 42 made of the silicon nitride film is formed in the region of the straight line 45, it becomes possible to make the second lower layer bank 42 fit the ink, and the light emitting region. 12, the flatness of the ink can be improved. Thereby, it is possible to emit light uniformly. Further, since the silicon nitride film is formed on the peripheral edge of the pixel electrode 32, the insulation of the pixel electrode 32 can be ensured.

(Fourth embodiment)
FIG. 7 is a schematic diagram showing the structure of the bank according to the fourth embodiment. (A) is the schematic top view which looked at the bank from the upper direction. (B) is a schematic cross section which follows the AA cross section of the bank shown to (a). (C) is a schematic cross section which follows the BB cross section of the bank shown to (a). Hereinafter, the bank structure will be described with reference to FIG. Note that the bank structure of the fourth embodiment differs from that of the first embodiment in that the lower layer bank is not formed below the upper layer bank in the straight line region. Hereinafter, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted or simplified here.

  As shown in FIG. 7, the region of the arc 44 in the opening 35 is configured by stacking a first lower layer bank 41, a second lower layer bank 42, and an upper layer bank 43 in a stepped manner from the glass substrate 13 side. In the region of the straight line 45 in the opening 35, only the upper layer bank 43 is formed.

  Thus, in addition to the first lower layer bank 41, the second lower layer bank 42 is formed in the region of the arc 44 in the opening 35, so that it is possible to make the ink particularly accustomed to the second lower layer bank 42. Ink can be filled in the region of the arc 44 that is relatively difficult to fill with ink.

  As described above in detail, according to the fourth embodiment, the following effects can be obtained in addition to the effect (1) of the first embodiment described above.

  (6) According to the fourth embodiment, since the area of the straight line 45 in the opening 35 is only the upper layer bank 43 and the lower layer bank 46 is not formed, the aperture ratio of this area (area in the X direction) is improved. be able to. Further, since the opening of the straight line region becomes wide, when ink is ejected, the ink is accumulated in a wide range, and it is possible to prevent the ink from overflowing.

  In addition, embodiment is not limited above, It can also implement with the following forms.

(Modification 1)
It is not limited to the structure of the bank 34 of the first to fourth embodiments described above, but may be the structure of the bank shown in FIGS. 8 and 9, for example. FIG. 8A is a schematic plan view of the bank as viewed from above. FIG. 8B is a schematic cross-sectional view along the AA cross section of the bank shown in FIG. FIG. 8C is a schematic cross-sectional view along the BB cross section of the bank shown in FIG. The structure of the bank 34 shown in FIG. 8 is different from that of the first embodiment in that the second lower layer bank 42 is formed so as to cover the first lower layer bank 41 in the region of the arc 44. The region of the arc 44 in the opening 35 is configured by stacking a first lower layer bank 41, a second lower layer bank 42, and an upper layer bank 43 in a step shape from the glass substrate 13 side. However, since the second lower layer bank 42 is formed so as to cover the first lower layer bank 41, the exposed lower layer bank 46 is only the second lower layer bank 42. The first lower layer bank 41 is formed to run on the peripheral edge of the pixel electrode 32. In the region of the straight line 45 in the opening 35, the first lower layer bank 41 and the upper layer bank 43 are formed from the glass substrate 13 side.

  According to the structure of this bank 34, only the second lower layer bank 42 made of a silicon nitride film is exposed and formed in the region of the arc 44. Therefore, compared with the first lower layer bank 41 made of a silicon oxide film, The second lower layer bank 42 can be made more familiar with ink, and the ink can be filled in the region of the arc 44 that is relatively difficult to fill. In addition, since the first lower layer bank 41 is formed so as to run over the peripheral edge of the pixel electrode 32, the insulating property of the pixel electrode 32 can be ensured. Further, since the first lower layer bank 41 made of a silicon oxide film is formed in the region of the straight line 45, the second lower layer bank 42 is formed as in the case where the second lower layer bank 42 made of a silicon nitride film and having high wettability is formed. It is possible to suppress a large amount of wasted ink on 42. Therefore, ink can be used efficiently.

  FIG. 9A is a schematic plan view of the bank as viewed from above. FIG. 9B is a schematic cross-sectional view along the AA cross section of the bank shown in FIG. FIG. 9C is a schematic cross-sectional view along the BB cross section of the bank shown in FIG. In the structure of the bank 34 shown in FIG. 9, only the first lower layer bank 41 is formed below the upper layer bank 43 in the region of the arc 44, and only the second lower layer bank 42 is formed below the upper layer bank 43 in the region of the straight line 45. The part in which is formed is different from the first embodiment. The region of the arc 44 in the opening 35 is configured by stacking the first lower layer bank 41 and the upper layer bank 43 in a stepped manner from the glass substrate 13 side. The first lower layer bank 41 is formed to run on the peripheral edge of the pixel electrode 32. The region of the straight line 45 in the opening 35 is configured by stacking the second lower layer bank 42 and the upper layer bank 43 in a stepped manner from the glass substrate 13 side. The second lower layer bank 42 is formed so as to run over the peripheral edge of the pixel electrode 32.

  According to the structure of the bank 34, the first lower layer bank 41 is formed in the region of the arc 44, so that the ink can be filled in the region of the arc 44, and the wettability made of the silicon nitride film. As in the case where the second lower layer bank 42 having a high height is formed, it is possible to suppress a large amount of wasted ink on the second lower layer bank 42. Therefore, ink can be used efficiently. Furthermore, since the second lower layer bank 42 made of a silicon nitride film is formed in the region of the straight line 45, it becomes possible to make the ink fit into the second lower layer bank 42 and improve the flatness of the ink in the light emitting region 12. be able to. Thereby, it is possible to emit light uniformly.

(Modification 2)
The shape of the opening 35 of the bank 34 described above (the shape seen from the normal direction of the glass substrate 13) is not limited to a track shape when seen in a plan view, and may be, for example, a shape as shown in FIGS. . A bank 71 shown in FIG. 10 is a diagram showing a common bank (hereinafter referred to as “common bank 71”) that partitions a pixel region including a plurality of light emitting elements. The region of the arc 44 in the opening 35 is configured by stacking a first lower layer bank 41, a second lower layer bank 42, and an upper layer bank 43 in a step shape from the glass substrate 13 side. A first lower layer bank 41 and a second lower layer bank 42 are formed between the pixel electrode 32 and the pixel electrode 32 in the opening 35. The region of the straight line 45 in the opening 35 is formed by stacking a first lower layer bank 41 and an upper layer bank 43 in a stepped manner from the glass substrate 13 side. That is, only the shape of the opening 35 is different, and the configuration of the lower layer bank 46 is the same as that of the first embodiment. The structure of the lower layer bank 46 shown in the second to fourth embodiments and the first modification may be applied to the common bank 71 without being limited to the configuration of the bank 71. According to this, the functional liquid can be filled in the region of the arc 44 that is difficult to fill with the functional liquid, and the aperture ratio in the X direction can be improved.

  A bank 75 shown in FIG. 11 is a rectangle having a different aspect ratio, and an arc 79 is formed at a corner connecting the straight line 77 of the long side and the straight line 78 of the short side and the straight lines 77 and 78 in the opening 76 of the bank 75. The formed part is different from the bank 34 of the first embodiment. The region on the short side including the region of the arc 79 in the opening 76 is configured by stacking the first lower layer bank 41, the second lower layer bank 42, and the upper layer bank 43 in a stepped manner from the glass substrate 13 side. On the other hand, the region on the long side is formed by stacking a first lower layer bank 41 and an upper layer bank 43 in a step shape from the glass substrate 13 side. The structure of the lower layer bank 46 is not limited to the configuration of the lower layer bank 46, and the structure of the lower layer bank 46 shown in the second to fourth embodiments and the first modification may be applied to the bank 75. Alternatively, the region for forming the two lower layer banks 46 (41, 42) may be formed only in the region of the arc 79. Further, it may be formed only in a partial area of the arc 79. According to this, it is possible to fill at least the portion of the arc 79 that is difficult to fill with the functional liquid with the functional liquid.

  A bank 81 shown in FIG. 12 is a rectangle having a different aspect ratio, and a portion having no arc at a corner is different from the bank 75 shown in FIG. The region on the short side in the opening 82 is configured by laminating a first lower layer bank 41, a second lower layer bank 42, and an upper layer bank 43 in a stepped manner from the glass substrate 13 side. On the other hand, the region on the long side is formed by stacking a first lower layer bank 41 and an upper layer bank 43 in a step shape from the glass substrate 13 side. The structure of the lower layer bank 46 is not limited to the structure of the lower layer bank 46, and the structure of the lower layer bank 46 shown in the second to fourth embodiments and the first modification may be applied to the bank 81. In addition, the region for forming the two lower layer banks 46 (41, 42) may be formed in a region including a part of the corner. According to this, the functional liquid can be filled at least in the corner portion where the functional liquid is difficult to be filled.

  A bank 85 shown in FIG. 13 is different from the bank 81 shown in FIG. 12 in that the aspect ratio is the same (square). The corner area in the opening 86 is formed by stacking the first lower layer bank 41, the second lower layer bank 42, and the upper layer bank 43 in a stepped manner from the glass substrate 13 side. On the other hand, the other region is configured by stacking the first lower layer bank 41 and the upper layer bank 43 in a stepped manner from the glass substrate 13 side. The structure of the lower layer bank 46 is not limited to the configuration of the lower layer bank 46, and the structure of the lower layer bank 46 shown in the second to fourth embodiments and the first modification may be applied to the bank 85. In addition, the region for forming the two lower layer banks 46 (41, 42) may be formed in a region including a part of the corner. According to this, the functional liquid can be filled at least in the corner portion where the functional liquid is difficult to be filled. If the openings having various shapes described above can satisfy the lyophilicity (or the lyophilicity does not change) even if the liquid repellency is not lowered, the lower layer bank 46 is formed. It may not be formed.

(Modification 3)
In the second and fourth embodiments described above, the first lower layer bank 41 and the second lower layer bank 42 are not formed below the upper layer bank 43 in the region of the straight line 45, but are not exposed to the opening 35. Thus, at least one of the first lower layer bank 41 and the second lower layer bank 42 may be formed on the peripheral edge of the pixel electrode 32. According to this, the insulation of the pixel electrode 32 can be ensured.

(Modification 4)
As described above, the lower layer bank 46 is not limited to being configured by the first lower layer bank 41 and the second lower layer bank 42. For example, the lower layer bank 46 may be configured by a plurality of layers. In addition, it is preferable that the selection method for exposing at least one of the first lower layer bank 41 and the second lower layer bank 42 is determined in consideration of insulation, ink filling property, surface treatment suitability, and the like.

(Modification 5)
As described above, the first lower layer bank 41 and the second lower layer bank 42 are not limited to patterning separately. For example, the first lower layer bank 41 made of a silicon oxide film and the second lower layer bank made of a silicon nitride film are used. Etching may be performed stepwise using the difference in etching rate with the bank 42.

(Modification 6)
As described above, the second lower layer bank 42 is not limited to being formed of a silicon nitride film. For example, tantalum oxide, magnesium oxide, or the like, which is a material having a high dielectric constant, may be used.

(Modification 7)
As described above, the method for filling the light emitting region 12 with the functional liquid is not limited to the droplet discharge method, and for example, a dispenser coating method may be used.

(Modification 8)
As described above, the electro-optical device is not limited to the organic EL device 11 as an example, and any electro-optical device may be used as long as it has a step of filling a bank with ink when manufacturing, for example, a liquid crystal having a color filter. It can be applied to devices, plasma displays, electronic paper, and the like.

1 is a schematic cross-sectional view showing a partial structure of an organic EL device according to a first embodiment. It is a schematic diagram which shows the structure of the bank in an organic electroluminescent apparatus, (a) is a schematic top view which looked at the organic electroluminescent apparatus from upper direction, (b) is a schematic in alignment with the AA cross section of the organic electroluminescent apparatus shown to (a). Sectional drawing and (c) are schematic sectional drawings which follow the BB cross section of the organic electroluminescent apparatus shown to (a). Process drawing which shows the manufacturing method of an organic electroluminescent apparatus. 1 is a schematic diagram illustrating a mobile phone including an organic EL device. It is a schematic diagram which shows the structure of the bank in the organic EL device which concerns on 2nd Embodiment, (a) is a schematic top view which looked at the organic EL device from the upper part, (b) is A of the organic EL device shown to (a). A schematic cross-sectional view along the -A cross section, (c) is a schematic cross-sectional view along the BB cross section of the organic EL device shown in (a). It is a schematic diagram which shows the structure of the bank in the organic EL device which concerns on 3rd Embodiment, (a) is a schematic top view which looked at the organic EL device from the upper part, (b) is A of the organic EL device shown to (a). A schematic cross-sectional view along the -A cross section, (c) is a schematic cross-sectional view along the BB cross section of the organic EL device shown in (a). It is a schematic diagram which shows the structure of the bank in the organic EL device which concerns on 4th Embodiment, (a) is a schematic top view which looked at the organic EL device from the upper part, (b) is A of the organic EL device shown to (a). A schematic cross-sectional view along the -A cross section, (c) is a schematic cross-sectional view along the BB cross section of the organic EL device shown in (a). It is a schematic diagram which shows the modification of the structure of a bank, (a) is a schematic top view which looked at the bank from the upper part, (b) is a schematic cross section along the AA cross section of the bank shown to (a), (c ) Is a schematic cross-sectional view along the BB cross section of the bank shown in FIG. It is a schematic diagram which shows the modification of the structure of a bank, (a) is a schematic top view which looked at the bank from the upper part, (b) is a schematic cross section along the AA cross section of the bank shown to (a), (c ) Is a schematic cross-sectional view along the BB cross section of the bank shown in FIG. It is a schematic diagram which shows the modification of the structure of a bank, (a) is a schematic top view which looked at the bank from the upper part, (b) is a schematic cross section along the AA cross section of the bank shown to (a), (c ) Is a schematic cross-sectional view along the BB cross section of the bank shown in FIG. The schematic plan view which shows the modification of bank shape. The schematic plan view which shows the modification of bank shape. The schematic plan view which shows the modification of bank shape.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Organic electroluminescent apparatus as an electro-optical device, 12 ... Light emission area | region, 13 ... Glass substrate as a board | substrate, 14 ... Circuit element layer, 15 ... Light emitting element layer, 16 ... Cathode, 17 ... Base protective film, 18 ... TFT element , 19 ... Semiconductor film, 21 ... Source region, 22 ... Drain region, 23 ... Channel region, 24 ... Gate insulating film, 25 ... Gate electrode, 26 ... First interlayer insulating film, 27 ... Second interlayer insulating film, 28 ... Contact hole, 29 ... signal line, 31 ... contact hole, 32 ... pixel electrode, 33 ... functional layer, 34, 75, 81, 85 ... bank, 35, 41a, 76, 82, 86 ... opening, 41 ... first Lower layer bank 42 ... Second lower layer bank 43 ... Upper layer bank 44,79 ... Arc, 45,77,78 ... Straight line 46 ... Lower layer bank 51 ... Hole injection layer 52 ... Light emitting layer 53 ... Display element 61 ... A mobile phone as a child equipment, 62 ... display unit, 63 ... operation button, 71 ... common bank.

Claims (11)

An electro-optical device having a plurality of light emitting regions,
A substrate,
A bank formed on the substrate excluding the light emitting region and formed so as to surround the light emitting region;
A functional layer disposed in an opening surrounded by the bank,
The bank has an upper layer bank and a plurality of lower layer banks having higher wettability than the upper layer bank,
The electro-optical device, wherein the lower layer bank has a smaller number of layers of the lower layer bank exposed in the second region than a number of layers of the lower layer bank exposed in the first region in the opening. The electro-optical device according to claim 1,
The opening has a corner when viewed from the normal direction;
The electro-optical device, wherein the first region is a region including a part of the corner of the opening. The electro-optical device according to claim 1,
The opening has an arc when viewed from the normal direction;
The electro-optical device, wherein the first region is a region including a part of the arc in the opening. The electro-optical device according to claim 1,
The opening has a short side and a long side when viewed from the normal direction,
The first region is a region on the short side of the opening,
The electro-optical device, wherein the second region is a region on the long side of the opening. The electro-optical device according to any one of claims 1 to 4,
The lower layer bank has a first lower layer bank and a second lower layer bank from the substrate side,
An electro-optical device, wherein a contact angle with respect to the liquid of the second lower layer bank is smaller than a contact angle with respect to the liquid of the first lower layer bank. The electro-optical device according to claim 5,
The first lower layer bank is a silicon oxide film,
The electro-optical device, wherein the second lower layer bank is a silicon nitride film. The electro-optical device according to claim 5 or 6,
The electro-optical device, wherein the first region is formed by exposing the second lower layer bank. The electro-optical device according to claim 5 or 6,
The first region is formed by exposing the first lower layer bank and the second lower layer bank,
The electro-optical device, wherein the second region is formed by exposing either the first lower layer bank or the second lower layer bank. An electro-optical device having a plurality of light emitting regions,
A substrate,
A bank formed on the substrate excluding the light emitting region and formed so as to surround the light emitting region;
A functional layer disposed in an opening surrounded by the bank,
The bank has an upper layer bank and a lower layer bank having higher wettability than the upper layer bank,
The electro-optical device, wherein the lower layer bank is exposed in a first region of the opening and is not exposed in a second region. The electro-optical device according to any one of claims 1 to 8,
Corresponding to each of the plurality of light emitting regions, further comprising: a pixel electrode formed on one surface of the substrate; and a common electrode provided on the opposite side of the pixel electrode across the functional layer, The electro-optical device, wherein the functional layer includes at least a light emitting layer.   An electronic apparatus comprising the electro-optical device according to any one of claims 1 to 10.

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