JP2009026671A - Electro-optical device, electronic apparatus, and method of manufacturing electro-optical device - Google Patents

Abstract

An electro-optical device, an electronic apparatus, and a method of manufacturing an electro-optical device that can suppress variations in light emission characteristics are provided.
An organic EL device includes a glass substrate, a circuit element layer, a light emitting element layer, and a cathode. The light emitting element layer includes a functional layer formed on the pixel electrode 32 and a bank 34 that partitions the functional layer. The bank 34 includes a first layer bank 41 and a second layer bank. Further, the bank 34 is formed in a track shape having a light emitting region 12 having a different aspect ratio and a region of an arc 44 formed on the short side of the light emitting region 12. The second layer bank has a first portion 42a and a second portion 42b, and the liquid repellency of the first portion 42a is relatively lower than the liquid repellency of the second portion 42b. The first portion 42 a has a circular arc 44 portion. The second portion 42 b has a straight line 45 portion.
[Selection] Figure 2

Description

  The present invention relates to an electro-optical device, an electronic apparatus, and an electro-optical device manufacturing method 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 ink and discharging the ink to a light emitting region on the substrate using an ink jet method. In the light emitting region on the base material, 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, a track-like opening having a long side and a short side is formed in a region corresponding to the light emitting region, for example. The inside of the arc formed on the short side has a problem that ink wettability is poor and ink is difficult to fill. On the other hand, there is a problem that ink tends to overflow on the long side. As a result, the thickness of the ink ejected to the opening varies, and as a result, there is a problem that uniform light emission cannot be obtained.

  Therefore, for example, as described in Patent Document 1, an inorganic material (for example, a silicon oxide film) for facilitating filling of the opening of the bank is partially exposed below the acrylic resin bank. There is known a method for improving the wettability of ink and making the film thickness in the bank uniform.

JP 2003-187970 A

  However, when the light emitting area becomes fine (that is, with high definition), the curvature of the arc increases, and the ink in the arc portion tends to recede particularly during the drying process. As a result, it becomes difficult to fill the ink, and further, if the ink is replenished high in order to ensure the film thickness, there is a problem that the ink tends to overflow on the long side. As a result, since there is a difference in the contact angle with respect to the ink on the long side and the short side, the thickness of the ink in the opening varies, and light cannot be emitted uniformly (the light emission characteristics vary). There is a problem.

  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 provided on at least a part of the substrate and one of the surfaces of the substrate excluding the light-emitting region. And 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 a first portion and a second portion. And the liquid repellency of the first part is lower than the liquid repellency of the second part.

  According to this configuration, since the liquid repellency of the first part is low (high wettability) compared to the second part of the bank, it becomes possible to make the liquid conform to the first part in the opening. The partial area can be filled with liquid. Furthermore, the liquid repellency of the second part can prevent the liquid from overflowing from the region of the second part in the opening. 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.

  Application Example 2 In the electro-optical device according to the application example, it is preferable that the opening has a corner, and the first portion includes a part of the corner of the opening.

  According to this configuration, since the liquid repellency of the first portion including a part of the corner in the opening is low (high wettability), it is possible to fill the corner with the liquid that is relatively difficult to fill. Furthermore, the liquid repellency of the second portion can prevent the liquid from overflowing from the region of the second portion.

  Application Example 3 In the electro-optical device according to the application example described above, it is preferable that the opening has an arc, and the first portion includes a part of the arc in the opening.

  According to this configuration, since the liquid repellency of the first portion including a part of the arc at the opening is low (high wettability), it is possible to fill the arc portion where the liquid is relatively difficult to fill. .

  Application Example 4 In the electro-optical device according to the application example, the opening has a long side and a short side, and the first portion includes a region on the short side of the opening, The second portion preferably includes a region on the long side of the opening.

  According to this configuration, the first portion including the short side region has low liquid repellency (high wettability), so that the first portion has a narrower width than the second portion and is relatively difficult to fill with liquid. It can be filled with liquid. Furthermore, the liquid repellency of the second portion can prevent the liquid from overflowing from the region of the second portion.

  Application Example 5 In the electro-optical device according to the application example, the bank is made of a bank material including a material having a photocatalytic action, and the first portion is a portion irradiated with energy, The second part is preferably a part not irradiated with the energy.

  According to this configuration, only the first portion of the bank material that has been irradiated with energy acts as a photocatalyst, and liquid repellency is reduced (lyophilicity is improved). Further, the second portion of the bank material that is not irradiated with energy exhibits liquid repellency due to, for example, the structure of polysiloxane in the material having a photocatalytic action. Therefore, the first portion having low liquid repellency and the second portion having high liquid repellency can be formed. As a result, it is possible to fill the region of the first part with the liquid, and it is possible to prevent the liquid from overflowing from the region of the second part.

  Application Example 6 In the electro-optical device according to the application example described above, it is preferable that the first portion has a smaller roughness than the surface roughness of the second portion.

  According to this configuration, since the roughness of the first portion is small, it is possible to make the first portion conform to the liquid, and the region of the first portion can be filled with the liquid. Furthermore, it is possible to prevent the liquid from overflowing from the region of the second part due to the roughness of the second part.

  Application Example 7 In the electro-optical device according to the application example, the surface of the first portion has a first contact angle with respect to the liquid, and the surface of the second portion has a contact angle with the liquid. The second contact angle is preferably larger than the first contact angle.

  According to this structure, since the contact angle with respect to the liquid of the 1st part is small compared with the 2nd part, the area | region of a 1st part can be filled with a liquid. Furthermore, since the contact angle with respect to the liquid of the 2nd part is large compared with the 1st part, it can suppress that a liquid overflows from the area | region of a 2nd part.

  Application Example 8 In the electro-optical device according to the application example, the pixel electrode formed on the one surface of the substrate corresponding to each of the plurality of light emitting regions, and the pixel sandwiching the functional layer And a common electrode provided on the opposite side of the electrode, wherein the functional layer includes 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, it is possible to suppress variations in the thickness of the light emitting layer, and to emit light uniformly in the light emitting region. Can do.

  Application Example 9 An electronic apparatus according to this application example includes the above-described electro-optical device.

  According to this configuration, an electronic device that can emit light uniformly can be obtained.

  Application Example 10 A method for manufacturing an electro-optical device according to this application example is a method for manufacturing an electro-optical device having a plurality of light emitting regions, in which a pixel electrode is formed for each light emitting region on a substrate. A step of forming a bank including a first portion and a second portion surrounding the pixel electrode on the substrate; and a droplet discharge method on the opening of the bank on the pixel electrode. A light emitting layer forming step of forming a light emitting layer; and a cathode forming step of forming a cathode on the opposite side of the pixel electrode with the light emitting layer interposed therebetween, wherein the bank forming step includes the liquid repellent of the first portion. It is characterized in that it is formed so that the property is lower than the liquid repellency of the second portion.

  According to this method, since the liquid repellency of the first portion is lower than that of the second portion of the bank (high wettability), it is possible to fill the region of the first portion in the opening with the liquid. . Furthermore, the liquid repellency of the second part can prevent the liquid from overflowing from the region of the second part in the opening. Therefore, the variation in the thickness of the liquid in the bank is suppressed, and as a result, the light can be emitted uniformly.

  Application Example 11 In the method of manufacturing the electro-optical device according to the application example, it is preferable that the opening has a corner, and the first portion includes a part of the corner of the opening.

  According to this method, since the liquid repellency of the first portion including a part of the corner in the opening is low (high wettability), it is possible to fill the corner with the liquid that is relatively difficult to fill. Furthermore, the liquid repellency of the second portion can prevent the liquid from overflowing from the region of the second portion.

  Application Example 12 In the method of manufacturing the electro-optical device according to the application example, it is preferable that the opening has an arc, and the first portion includes a part of the arc of the opening.

  According to this method, since the liquid repellency of the first part including a part of the arc at the opening is low (high wettability), the liquid can be filled into the arc part that is relatively difficult to fill with the liquid. .

  Application Example 13 In the method of manufacturing the electro-optical device according to the application example, the opening has a long side and a short side, and the first portion is a region on the short side of the opening. Preferably, the second portion includes a region on the long side of the opening.

  According to this method, since the liquid repellency of the first portion including the short side region is low (high wettability), the first portion is narrower than the second portion and relatively difficult to fill with liquid. It can be filled with liquid. Furthermore, the liquid repellency of the second portion can prevent the liquid from overflowing from the region of the second portion.

  Application Example 14 In the method of manufacturing the electro-optical device according to the application example, the bank forming step includes an application step of applying a coating liquid containing a material having a photocatalytic action on the pixel electrode, and the coating liquid. Forming a bank layer by drying the layer, patterning the bank layer into the shape of the bank and forming the opening in a region corresponding to the light emitting region, and the bank And an energy irradiation step of irradiating the first region with energy to form the first portion.

  According to this method, only the first portion irradiated with energy in the bank (titanium oxide) acts as a photocatalyst, and liquid repellency is reduced (lyophilicity is improved). In addition, the second portion that is not irradiated with energy in the bank exhibits liquid repellency due to, for example, the structure of polysiloxane in the material having a photocatalytic action. Therefore, a bank including the first region with low liquid repellency and the second region with high liquid repellency can be formed. As a result, it is possible to fill the liquid in the first region, and it is possible to prevent the liquid from overflowing from the second region.

  Application Example 15 In the method of manufacturing an electro-optical device according to the application example, in the bank formation step, the second portion is formed from a second material, and the first portion is more liquid repellent than the second material. It is formed from a low first material.

  According to this method, the region of the first portion can be filled with the first portion made of the first material having a lower liquid repellency than the second portion made of the second material. Furthermore, the liquid repellent property of the second part made of the second material can prevent the liquid from overflowing from the region of the second part.

  Application Example 16 In the method of manufacturing the electro-optical device according to the application example, in the bank formation step, the first region of the bank made of an organic material is subjected to plasma treatment to thereby reduce the first portion having low liquid repellency. And forming the second portion having high liquid repellency by subjecting the second region of the bank to plasma treatment longer than the plasma treatment time applied to the first region.

According to this method, by increasing the plasma processing (for example, CF ₄ plasma processing) time for the second region as compared with the plasma processing (for example, O ₂ plasma processing) time for the first region, Since the liquid repellency can be increased, it is possible to fill the region of the first part with liquid and to prevent the liquid from overflowing from the region of the second part due to the liquid repellency of the second part. Can do.

  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. A gate electrode 25 (scanning line) made of aluminum (Al), molybdenum (Mo), tantalum (Ta), titanium (Ti), tungsten (W), or the like is formed on the gate insulating film 24. 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 a different aspect ratio and a region of an arc 44 formed on the short side of the light emitting region 12.

The bank 34 is configured by laminating a first layer bank 41 located on the glass substrate 13 side and a second layer bank 42 located farther from the glass substrate 13 than the first layer bank 41. Examples of the material of the first layer bank 41 include inorganic materials such as SiO ₂ , TiO ₂ , and SiN. As a material of the second layer bank 42, for example, a material containing polysiloxane and titanium oxide is used. In the present embodiment, the bank 34 is formed by a laminated structure of the first layer bank 41 and the second layer bank 42, but may be formed by a single layer of the second layer bank 42.

  The first 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 layer bank 41 are arranged so as to partially overlap in plan view (illustration is omitted in FIG. 2A). In other words, the first layer bank 41 is formed in a region excluding the light emitting region 12. Further, the end portion of the first layer bank 41 is formed so as to be disposed closer to the center side of the pixel electrode 32 than the end portion of the second layer bank 42.

  In the present embodiment, the first layer bank 41 is formed to run on the peripheral edge of the pixel electrode 32, but the side surface of the first layer bank 41 is formed to be flush with the side surface of the second layer bank 42. Also good. In this case, the light emitting region 12 can be formed wider than the case where the first layer bank 41 is formed so as to run on the peripheral edge of the pixel electrode 32.

  On the other hand, the second layer bank 42 is formed, for example, in a trapezoidal shape having an inclined surface when viewed in cross section. The second layer bank 42 has a first portion 42a and a second portion 42b, and the liquid repellency of the first portion 42a is relatively lower than the liquid repellency of the second portion 42b. The first portion 42 a having low liquid repellency (that is, having high wettability) includes a portion of an arc 44 in the opening 35 of the second layer bank 42. The second portion 42 b having high liquid repellency (that is, low wettability) includes a portion of the straight line 45 in the opening 35 of the second layer bank 42. In addition, the 1st part 42a contains the inclined surface formed in the part of the circular arc 44 (refer FIG.2 (b)). Further, the second portion 42 b includes an inclined surface formed at the portion of the straight line 45.

  Here, “low liquid repellency” means that the contact angle with the liquid is relatively small. That is, it can be said that the liquid is easily filled in the region of the arc 44 with low liquid repellency (see FIG. 2A). On the other hand, “high liquid repellency” means that the contact angle with the liquid is relatively large. In other words, it can be said that the liquid is less likely to overflow from the portion of the straight line 45 (see FIG. 2A) where the liquid repellency is increased. The detailed material and manufacturing method of the second layer bank 42 will be described later.

  The functional layer 33 is formed, for example, in a region where the hole injection layer 51 and the light emitting layer 52 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 the first layer bank 41 and the second layer bank 42 as side walls (see FIG. 2B).

  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.

  The light emitting layer 52 is formed on the hole injection layer 51. Due to the presence of the first portion 42 a of the second layer bank 42, the functional liquid discharged when forming the light emitting layer 52 is likely to spread (fill easily) inside the arc 44 in the opening 35. Further, the presence of the second portion 42 b of the second layer bank 42 prevents the functional liquid from overflowing from the portion of the straight line 45 in the opening 35 to the outside. Therefore, the light emitting layer 52 can be easily formed in the bank 34, and the thickness of the light emitting layer 52 can be made uniform.

  The cathode 16 is formed on the light emitting layer 52 and the second layer bank 42. 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.

  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 FIG.

  As shown in FIG. 3, in the method for manufacturing the organic EL device 11, a bank is formed by steps S1 to S5, 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 (pixel electrode formation step), a pixel electrode 32 made of ITO is formed on the circuit element layer 14.

In step S <b> 3, the first layer bank 41 is formed on the circuit element layer 14 and the pixel electrode 32. Specifically, first, a layer (first layer bank layer) containing, for example, silicon oxide (SiO ₂ ), which is a material of the first layer bank 41, is formed by the CVD (Chemical Vapor Deposition) method or the like. And it forms so that the pixel electrode 32 may be covered. Next, using the photolithography technique and the etching technique, the opening 41a and the first layer bank 41 are formed in a region corresponding to the light emitting region 12 in the first layer bank layer. When the side surface of the first layer bank 41 and the side surface of the second layer bank 42 are formed so as to be flush with each other, the opening 41a is not formed in step S3, but the opening in the later step S4. The opening 41a may be formed simultaneously with the formation of the portion 42c.

  Here, the coating liquid used as the material of the second layer bank 42 will be described. The coating liquid contains titanium oxide and polysiloxane. Among these, titanium oxide acts as a photocatalyst, and changes the wettability of the surface of the first portion 42a by irradiating energy to the first region corresponding to the first portion 42a of the second layer bank 42. . Further, the wettability of the entire film of the first portion 42a may be changed without being limited to the surface.

  On the other hand, polysiloxane has a liquid-repellent substituent directly bonded to Si primitive constituting polysiloxane. Examples of the substituent having liquid repellency include an alkyl group, a fluoroalkyl group, a vinyl group, an amino group, a phenyl group, and an epoxy group. In this embodiment, a fluoroalkyl group is used. Due to such a structure of polysiloxane, the second portion 42b of the second layer bank 42 formed from the coating solution exhibits liquid repellency. Further, when energy is applied to the layer made of the coating solution, the substituent is decomposed by the action of the photocatalyst, and lyophilicity (low liquid repellency) is developed. That is, only the first portion 42a of the second layer bank 42 irradiated with energy is selectively improved in lyophilicity, and the remaining second portion 42b has the property of maintaining liquid repellency.

  In step S4 (coating process, bank layer forming process, opening forming process), patterning is performed on the first layer bank 41 into the shape of the second layer bank. First, the coating liquid of the material for the second layer bank 42 is applied onto the first layer bank 41 and the light emitting region 12. Next, the coating liquid is dried to form a second bank layer as a bank layer. Thereafter, an opening 42c is formed in a region corresponding to the light emitting region 12 in the second bank layer. Thereby, the shape of the second layer bank 42 is completed.

In step S5 (energy irradiation step), the first layer 42a in the second layer bank 42 is formed with low liquid repellency (high wettability) to complete the second layer bank 42. First, a mask in which a region corresponding to the first portion 42a is opened is disposed. Then, energy is applied only to the first portion 42a (first region) through the mask. As a condition for energy irradiation, for example, exposure is performed for 30 seconds with an ultrahigh pressure mercury lamp (30 mW / cm ² , wavelength 365 nm). The first portion 42a changes in a direction in which the contact angle with the liquid decreases due to the action of titanium oxide accompanying energy irradiation. As a result, the liquid repellency of the first portion 42a can be made lower (higher wettability) than the liquid repellency of the second portion 42b, and the first portion 42a having a reduced contact angle and a high contact angle. A second layer bank 42 having a second portion 42b can be formed.

  As described above, the first portion 42a of the second layer bank 42 has a contact angle with the liquid (functional liquid) of 30 ° (first contact angle), and the second portion 42b has a contact angle with the liquid (functional liquid) of 80. The bank formation is completed at (° (second contact angle)).

  In subsequent step S11, a functional liquid containing the material of the hole injection layer 51 is applied to the light emitting region 12 surrounded by the first layer bank 41 and the second layer bank 42 on the pixel electrode 32 by a droplet discharge method (for example, Ink jet method). Specifically, the functional liquid droplets are discharged toward a recess having the pixel electrode 32 as a bottom and the first layer bank 41 and the second layer bank 42 as side walls. 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.

  In step S13 (light emitting layer forming step), a 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 portion of the arc 44 in the opening 35 of the second layer bank 42 is the first portion 42a having low liquid repellency, the functional liquid (for example, a film formed by wetting the first portion 42a) , The functional liquid of the light emitting layer 52 can be prevented from retreating. Further, since the portion of the straight line 45 in the opening 35 of the second layer bank 42 is the second portion 42b having high liquid repellency, it is possible to prevent the functional liquid from overflowing outside the bank 34. Thereby, it can suppress that the thickness of the light emitting layer 52 in the bank 34 becomes non-uniform | heterogenous.

  In step S14 (light emitting layer forming step), 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 (cathode formation step), 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 portion of the arc 44 that is relatively difficult to fill with the functional liquid in the opening 35 of the second layer bank 42 is the first portion 42a having low liquid repellency. The functional liquid (for example, the functional liquid of the light emitting layer 52) can be made to conform to the first portion 42a, and the area inside the arc 44 can be filled with the functional liquid. In addition, since the portion of the straight line 45 of the opening 35 is the second portion 42 b having high liquid repellency, the functional liquid can be prevented from overflowing outside the bank 34. As a result, the thickness of the light emitting layer 52 in the light emitting region 12 can be formed uniformly, and light can be emitted uniformly.

  (2) According to the first embodiment, since the liquid repellency is lowered by changing the wettability of the surface of the first portion 42a using a photocatalyst, the first portion 42a and the second portion 42b are different. There is no step of patterning with the material, and the second bank can be formed with the same material.

(Second Embodiment)
FIG. 5 is a process diagram showing a method for manufacturing the organic EL device of the second embodiment. Hereinafter, a method for manufacturing the organic EL device will be described with reference to FIG. In the method of manufacturing the organic EL device 11 of the second embodiment, an acrylic resin (first material) is used for the first portion 42a of the second layer bank 42, and a fluorine-based material is added to the second portion 42b. The portion using the acrylic resin (second material) is different from the first embodiment. 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.

  First, the structure of the organic EL device 11 of the second embodiment will be described. In the organic EL device 11, as described above, for example, the first region including the arc 44 in the opening 35 of the second layer bank 42 is the first portion 42a made of an acrylic material. The second region including the straight line 45 in the opening 35 of the second layer bank 42 is a second portion 42b made of an acrylic material to which a fluorine-based material is added.

  Here, fluorine added to the acrylic material will be described. Fluorine has a very low surface energy. Therefore, the surface of a substance containing a large amount of fluorine has a smaller critical surface tension. Accordingly, the critical surface tension of the surface of the substance having a small fluorine content is increased as compared with the critical surface tension of the surface of the substance having a high fluorine content. This means that the surface of the substance having a low fluorine content is a lyophilic region compared to the surface of the substance having a high fluorine content. Hereinafter, a method for manufacturing the organic EL device 11 according to the second embodiment will be described. The steps from Step S1 to Step S3 are the same as those in the first embodiment.

  In step S <b> 21, the first portion 42 a of the second layer bank 42 is formed on the first layer bank 41. Examples of the material of the first portion 42a having low liquid repellency include acrylic resins as described above. First, an acrylic resin is formed on the glass substrate 13 including the first layer bank 41 by vapor deposition. Next, patterning is performed on the shape of the first portion 42a by a photolithography technique and an etching technique.

  In step S22, the second portion 42b is formed adjacent to the first portion 42a on the first layer bank 41. Examples of the material of the second portion 42b having high liquid repellency include an acrylic resin to which a fluorine-based material is added as described above. First, an acrylic resin to which a fluorine-based material is added is formed on the glass substrate 13 including the first layer 42a and the first portion 42a of the second layer bank 42 by vapor deposition. Next, patterning is performed on the shape of the second portion 42b by a photolithography technique and an etching technique. The film thickness of the second portion 42b having high liquid repellency (high contact angle) is preferably larger than the film thickness of the first portion 42a having low liquid repellency (low contact angle). Thereby, it is possible to prevent the liquid from overflowing from the portion of the straight line 45 where the liquid easily overflows in the opening 35 of the bank 34.

  Thus, the second layer bank 42 having the first portion 42a made of acrylic resin and the second portion 42b made of acrylic resin to which a fluorine-based material is added is completed. The first part 42a has a contact angle with the functional liquid of 30 °, and the second part 42b has a contact angle with the functional liquid of 80 °. Thereafter, similarly to the first embodiment, the organic EL device 11 is completed by performing Steps S11 to S16.

  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.

  (3) According to the second embodiment, the first portion 42a including the arc 44 portion is formed of an acrylic resin, and the second portion 42b including the straight line 45 portion is added with a fluorine-based material. Since the first part with low liquid repellency and the second part with high liquid repellency can be made by forming in this manner, the number of manufacturing steps increases, but the energy as in the first embodiment is irradiated. Two liquid-repellent portions can be formed without any problem.

(Third embodiment)
FIG. 6 is a process diagram showing a method for manufacturing the organic EL device of the third embodiment. Hereinafter, a method for manufacturing the organic EL device will be described with reference to FIG. Note that the organic EL device 11 of the third embodiment has a longer plasma processing time applied to the second region corresponding to the second portion 42b than the plasma processing time applied to the first region corresponding to the first portion 42a. By performing (increasing the number of times), the portion that separates the first portion 42a having low liquid repellency from the second portion 42b having high liquid repellency is different from the first embodiment. 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. The steps from Step S1 to Step S3 are the same as those in the first embodiment.

  In step S31, for example, acrylic resin for forming the second layer bank 42 is laminated on the glass substrate 13 including the first layer bank 41 to form a second layer bank layer. Examples of the method for forming the second bank layer include vapor deposition.

  In step S32, patterning is performed from the second layer bank layer to the shape of the second layer bank. Specifically, patterning is performed using a photolithography technique and an etching technique.

In step S33, in the second layer bank 42, a first portion 42a having a low liquid repellency and a second portion 42b having a high liquid repellency are formed. Specifically, for example, oxygen plasma processing using oxygen (O ₂ ) gas is performed on the first region corresponding to the first portion 42 a in the second layer bank 42. On the other hand, for example, carbon tetrafluoride (CF ₄ ) plasma treatment using tetrafluoromethane is performed on the second region corresponding to the second portion 42b. Further, the plasma treatment applied to the second region is performed, for example, 10 times more than the plasma treatment applied to the first region.

  More specifically, the oxygen plasma treatment for the first region 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, a plate conveyance speed of 0.5 mm / sec to 10 mm / sec, and a substrate temperature of 70 ° C. By processing under the condition of 90 ° C., the first portion 42a can be made lyophilic (low liquid repellency).

  On the other hand, the carbon tetrafluoride plasma treatment for the second region 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 performing the treatment at 70 ° C. to 90 ° C., the second portion 42b can be made liquid repellent (high liquid repellency). Note that the carbon tetrafluoride plasma treatment for the second region is performed 10 times, for example.

  Thus, the second layer bank 42 having the first portion 42a having low liquid repellency and the second portion 42b having high liquid repellency is completed. The first portion 42a has a surface roughness Ra of 0.9 nm and a contact angle with the functional liquid of 50 °. The second portion 42b has a surface roughness Ra of 15 nm and a contact angle with the functional liquid of 80 °. In addition, after step S33, the organic EL device 11 is completed by performing steps S11 to S16 similarly to the first embodiment.

  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.

  (4) According to the third embodiment, the plasma treatment is performed on the first region and the second region, and the plasma irradiation time is changed, so that the first portion 42a having low liquid repellency and the liquid repellency are reduced. Since the high second portion 42b is formed, the first portion 42a and the second portion 42b can be formed relatively easily and can be performed in a general processing step.

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

(Modification 1)
The shape of the opening 35 of the bank 34 described above 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 illustrated in FIG. 7 is a diagram illustrating a common bank that partitions a pixel region including a plurality of light emitting elements. The second layer bank 42 constituting the bank 71 is a second portion 42b having high liquid repellency adjacent to the light emitting region 12 (including the straight line 45) and the other region (including the portion of the arc 44). A first portion 42a having low liquid repellency. According to the bank 71, since the arc portion 44 in the opening 72 is the first portion 42a having low liquid repellency, the functional liquid (for example, the light emitting layer 52) is formed by being wetted with the first portion 42a. It is possible to prevent the functional fluid from retreating. In addition, since the portion of the straight line 45 in the opening 72 is the second portion 42 b having high liquid repellency, the functional liquid can be prevented from overflowing outside the bank 71. Further, in the bank 71, the presence of the first portion 42a that does not include the portion of the arc 44 makes it possible to suppress poor filling when sufficient functional liquid does not enter the light emitting region 12. Therefore, uniform light emission characteristics can be obtained in the light emitting region 12.

  The bank 75 shown in FIG. 8 is a rectangle having a different aspect ratio, and in the opening 76 of the bank 75, a long-side straight line 77 and a short-side straight line 78, and arcs 79 at the corners connecting the straight lines 77 and 78, respectively. The formed part is different from the bank 34 of the first embodiment. The second layer bank 42 constituting the bank 75 has, for example, a first portion 42 a including a portion of the arc 79 and a second portion 42 b not including the portion of the arc 79. According to this, since the portion on the short side in the opening 76 is the first portion 42a having low liquid repellency, the functional liquid can be filled in the region on the short side that is relatively difficult to fill with liquid. it can. In addition, since the portion on the long side of the opening 76 is the second portion 42b having high liquid repellency, the overflow of the functional liquid from the portion on the long side can be suppressed. Moreover, it is not limited to the said structure, For example, you may make it make only the part of the circular arc 79 which does not contain a straight line the 1st part 42a, and the other part be the 2nd part 42b. Further, the part including a part of the corner may be the first part 42a, and the other part may be the second part 42b. 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. 9 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. In the second layer bank 42 constituting the bank 81, for example, the portion on the short side (the straight line 78 side) in the opening 82 is the first portion 42a, and the portion on the long side (the straight line 77 side) is the second portion. A portion 42b is formed. Moreover, it is not limited to the said structure, A corner vicinity is good also as the 1st part 42a, and another area | region is good also as the 2nd part 42b. Further, the part including a part of the corner may be the first part 42a, and the other part may be the second part 42b. According to this, since no arc is formed at the portion connecting the corners, it is difficult to fill the entire area of the light emitting region 12 with the functional liquid, but it is possible to fill the functional liquid over a wider range. The light emission characteristics in can be made more uniform. In addition, the light emitting area can be widened as compared with the case where arcs are provided at the corners.

  The bank 85 shown in FIG. 10 is different from the bank 81 shown in FIG. 9 in that the aspect ratio is the same (square). In the bank 85, for example, the first portion 42a is near the corner of the opening 86, and the other portion is the second portion 42b. According to this, since the liquid repellency of the corner part which is hard to be filled with the functional liquid is low, the functional liquid can be easily filled. In addition, in the openings of the various shapes described above, if the part can satisfy the lyophilicity (or the part where the lyophilicity does not change) without reducing the liquid repellency, the liquid repellency is improved. You may make it not perform the process to make low.

(Modification 2)
It is not limited to forming the 1st part 42a and the 2nd part 42b using the method like above-mentioned 1st Embodiment-3rd Embodiment, For example, the 2nd part is utilized using cutting, deformation, etc. The liquid repellent property of the second portion 42b may be improved by roughening the b 42b in a wave shape or a jagged shape.

(Modification 3)
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 4)
As described above, the organic EL device 11 is not limited to the example of the electro-optical device, and any liquid crystal having a color filter may be used as long as it has a step of filling a bank with liquid when manufacturing. 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). It is sectional drawing, (c) is a schematic cross section which follows 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. Process drawing which shows the manufacturing method of the organic electroluminescent apparatus concerning 2nd Embodiment. Process drawing which shows the manufacturing method of the organic electroluminescent apparatus concerning 3rd Embodiment. 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. The schematic plan view which shows the modification of bank shape.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Organic EL device as an electro-optical device, 12 ... Light emitting region, 13 ... Glass 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, 71, 75, 81, 85 ... bank, 35, 41a, 42c, 72, 76, 82, 86 ... opening, 41 ... 1st layer bank, 42 ... 2nd layer bank, 42a ... 1st part, 42b ... 2nd part, 44, 79 ... Arc, 45, 77, 78 ... Straight line, 51 ... Hole injection layer, 52 ... Light emitting layer 53, display elements, 6 ... mobile phone as an electronic device, 62 ... display unit, 63 ... operation button.

Claims (16)

An electro-optical device having a plurality of light emitting regions,
A substrate,
A bank formed on at least a part of a region excluding the light emitting region of one surface of the substrate and formed so as to surround the light emitting region;
A functional layer disposed in an opening surrounded by the bank,
The bank has a first portion and a second portion,
An electro-optical device, wherein the liquid repellency of the first portion is lower than the liquid repellency of the second portion. The electro-optical device according to claim 1,
The opening has a corner;
The electro-optical device, wherein the first portion includes a part of the corner of the opening. The electro-optical device according to claim 1,
The opening has an arc;
The electro-optical device, wherein the first portion includes a part of the arc of the opening. The electro-optical device according to any one of claims 1 to 3,
The opening has a long side and a short side,
The first portion includes a region on the short side of the opening,
The electro-optical device, wherein the second portion includes a region on the long side side of the opening. The electro-optical device according to any one of claims 1 to 4,
The bank is composed of a bank material including a material having a photocatalytic action,
The first portion is a portion irradiated with energy,
The electro-optical device, wherein the second part is a part not irradiated with the energy. The electro-optical device according to any one of claims 1 to 4,
The electro-optical device according to claim 1, wherein the first portion has a smaller roughness than the surface roughness of the second portion. The electro-optical device according to any one of claims 1 to 6,
The surface of the first portion has a first contact angle with respect to the liquid,
The electro-optical device, wherein the surface of the second portion has a second contact angle larger than the first contact angle with respect to the liquid. The electro-optical device according to any one of claims 1 to 7,
A pixel electrode formed on the one surface of the substrate corresponding to each of the plurality of light emitting regions;
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 claim 1. A method of manufacturing an electro-optical device having a plurality of light emitting regions,
A pixel electrode forming step of forming a pixel electrode for each of the light emitting regions on the substrate;
Forming a bank having a first portion and a second portion surrounding the pixel electrode on the substrate;
A light emitting layer forming step of forming a light emitting layer in the opening of the bank on the pixel electrode using a droplet discharge method;
A cathode forming step of forming a cathode on the opposite side of the pixel electrode across the light emitting layer, and
The method of manufacturing an electro-optical device, wherein the bank forming step is formed such that the liquid repellency of the first portion is lower than the liquid repellency of the second portion. The method of manufacturing an electro-optical device according to claim 10,
The opening has a corner;
The method of manufacturing an electro-optical device, wherein the first portion includes a part of a corner of the opening. The method of manufacturing an electro-optical device according to claim 10,
The opening has an arc;
The method of manufacturing an electro-optical device, wherein the first portion includes a part of an arc of the opening. A method for manufacturing an electro-optical device according to any one of claims 10 to 12,
The opening has a long side and a short side,
The first portion includes a region on the short side of the opening,
The method of manufacturing an electro-optical device, wherein the second portion includes a region on the long side of the opening. A method for manufacturing an electro-optical device according to any one of claims 10 to 13,
The bank forming step includes a coating step of applying a coating liquid containing a material having a photocatalytic action on the pixel electrode;
A bank layer forming step of drying the coating liquid to form a bank layer; and
An opening forming step of patterning the bank layer into the shape of the bank to form the opening in a region corresponding to the light emitting region;
Irradiating energy to a first region in the bank to form the first portion; and
A method for manufacturing an electro-optical device. A method for manufacturing an electro-optical device according to any one of claims 10 to 13,
In the bank forming step, the second portion is formed from a second material, and the first portion is formed from a first material having lower liquid repellency than the second material. . A method for manufacturing an electro-optical device according to any one of claims 10 to 13,
The bank forming step performs a plasma treatment on the first region of the bank made of an organic material to form the first portion having low liquid repellency,
A method of manufacturing an electro-optical device, wherein the second region of the bank is subjected to plasma treatment longer than the plasma treatment time applied to the first region to form the second portion having high liquid repellency.

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