JP2004259696A - Electroluminescent device and manufacturing method of the same, and electronic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve reliability of a display device by sufficiently absorbing or removing water and oxygen, even if a frame is narrower, for substrate sealing technology of an electroluminescent device having a top emission structure. <P>SOLUTION: On a substrate 2 having a plurality of light emitting parts A, a transparent sealing member 604 capable of housing the light emitting parts A is opposingly arranged, and the space between the substrate 2 and the sealing member 604 is sealed. On the top surface of the substrate 2 or the sealing member 604, a getter material 13 for absorbing or removing the oxygen or water is provided. The getter material 13 is arranged in an area between adjacent light emitting parts A in a plane view. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

  The present invention relates to an electroluminescence device and a method for manufacturing the same, and an electronic device including the electroluminescence device, and more particularly, to a substrate sealing technique for a display device having a top emission structure.

2. Description of the Related Art Hitherto, a device using an electroluminescence (hereinafter, also simply referred to as EL) display device for a display portion of a portable device such as a mobile phone or a PDA or a personal computer has been developed.
An EL display device includes a plurality of light emitting units having an EL layer (light emitting layer) on a substrate surface, and performs desired display by independently controlling driving of each light emitting unit. The EL display devices can be classified into, for example, a bottom emission type in which light is extracted from the element substrate side and a top emission type in which light is extracted from the sealing member side, depending on a difference in a direction in which light is extracted from the light emitting layer. For the reasons such as the degree of freedom of material selection, a bottom emission type structure has been mainly studied so far.

  On the other hand, in the field of display devices, there is a strong need for larger size, higher definition, and higher brightness, and research and development for larger size EL display devices are being actively conducted. However, when the size of the above-described bottom emission type EL display device is increased, it is necessary to increase the thickness of a wiring for supplying a signal to an electrode, which causes a problem that the aperture ratio of a pixel is reduced. In addition, when the aperture ratio is reduced in this manner, a large current flows through the light emitting layer in order to secure the brightness of the pixel, which causes a problem that the product life is shortened. For this reason, in recent years, a top emission type structure in which the aperture ratio of a pixel is not affected by a structure such as a wiring has attracted attention and has been actively studied.

By the way, it is known that the above-mentioned light emitting part is deteriorated by oxygen or moisture. For this reason, the substrate surface on which the light emitting section is formed is covered with a sealing substrate having a getter material such as silica gel disposed on the inner surface. In a top emission type display device, since high transparency is required for a sealing substrate, for example, as shown in Patent Documents 1 and 2, a getter material and a display region (a plurality of pixels are collectively arranged) A structure has been proposed in which a getter material is arranged outside a display area so that the area does not overlap with the area in a plan view.
JP 2000-208252 A Japanese Patent No. 2686169

However, when the peripheral edge of the display region is narrowed, the above-described structure in which the getter material is disposed around the peripheral portion of the display region reduces the installation area of the getter material, and may not be able to sufficiently remove oxygen, moisture, and the like. .
The present invention has been made in view of the above-described problems, and has been made in consideration of the above-described problems. Even when the frame is narrowed, a top-emission type electronic device capable of sufficiently absorbing or removing moisture and oxygen to improve the reliability of a display device is provided. It is an object of the present invention to provide a luminescence device, a method of manufacturing the luminescence device, and an electronic device including the display device.

  In order to achieve the above object, an electroluminescence device according to the present invention has a light emitting portion in which a first electrode, a functional layer including a light emitting layer, and a transparent second electrode are sequentially stacked from a lower layer side. A plurality of substrates provided therein, and a transparent sealing member that is disposed to face the substrate and that can accommodate the light-emitting portion.In a space sealed by the substrate and the sealing member, oxygen or A getter material for absorbing or removing moisture is provided, and the getter material is arranged in a region between adjacent light emitting units in a plan view.

  In this configuration, since the getter material is arranged in the non-light-emitting region that does not contribute to display (the region between the adjacent light-emitting portions), the display quality is not deteriorated. In addition, even when the frame is narrowed, the arrangement area of the getter material can be secured to a certain value or more, so that the intrusion of oxygen or moisture into the light emitting portion is effectively prevented, and the display device has high luminance and long life. be able to. Note that the functional layer is configured as a laminate of, for example, a light emitting layer and an electron transporting / injecting layer or a hole transporting / injecting layer for transporting / injecting electrons and holes into the light emitting layer. Further, the functional layer may be constituted by the light emitting layer alone.

As such a display device, for example, a configuration in which a partition wall for partitioning the light emitting units is provided on the substrate, and the getter material is provided at a position on an upper layer side of the partition wall on the outermost surface of the substrate. it can.
The present display device is, for example, a step of forming a plurality of first electrodes on a substrate, a step of forming partitions on the substrate to partition the first electrodes, and the partitioning of the partitions by an inkjet method. Forming a functional layer including a light-emitting layer in each of the regions, forming a transparent second electrode on the functional layer, and forming an upper layer side of the partition on the outermost surface of the substrate. A step of forming a getter material for absorbing or removing oxygen or moisture, and disposing a transparent sealing member facing the substrate surface on the side where the second electrode is formed, and forming a gap between the substrate and the sealing member. And sealing the space.

In this display device, a method in which a getter material is patterned by a vacuum deposition method using a mask, a sputtering method, a CVD method, or the like, or a method in which the getter material is dispersed in a liquid, discharged by an inkjet method, and dried to form a pattern is used. Thereby, the accuracy of the arrangement can be improved. For this reason, a bright display can be realized by minimizing the overlap between the arrangement region of the getter material and the light emitting region (the region where the light emitting layer is formed) in plan view.
When an opaque material is used for the getter material or when the getter material is formed to be thick, the getter material functions as a light-shielding layer and can prevent color bleeding caused by colored lights emitted from adjacent light-emitting portions. Thereby, high-contrast display can be realized.

Further, a getter material may be provided on the outermost surface of the sealing member. In this case, the getter material is provided only in the region between the adjacent light emitting units in plan view.
The present display device includes, for example, forming a plurality of first electrodes on a substrate, forming partitions on the substrate to partition the first electrodes, and forming, in an ink-jet method, each region partitioned by the partitions. Forming a functional layer including a light-emitting layer, forming a transparent second electrode on the functional layer, and supplying oxygen or moisture to a position of the transparent sealing member facing the region where the partition wall is formed. A step of forming a getter material to be absorbed or removed, and positioning the sealing member with respect to the substrate so that the getter material is disposed in the formation region of the partition wall in plan view; Sealing the space between the sealing member and the sealing member. At this time, which of the step of forming the light emitting element (the laminate of the first electrode, the functional layer, and the second electrode) on the substrate and the step of forming the getter material on the sealing member is performed first. You may.

  In this display device, when the getter material is formed using a vacuum evaporation method or the like, a light-emitting portion is not damaged and a highly reliable display device can be realized. In addition, by using an opaque material or forming the getter material thicker as the getter material, it is possible to prevent color bleeding between colored lights and realize a high-contrast display.

The getter material may include at least one of an alkali metal, an alkaline earth metal, an oxide of an alkaline earth metal, a hydroxide of an alkali metal or an alkaline earth metal, silica gel, and a zeolite compound. preferable.
The hydroxide of an alkali metal or an alkaline earth metal reacts with water and changes into an oxide, thereby acting as a dehydrating material. Similarly, the alkaline earth metal oxide reacts with water and changes to a hydroxide, thereby acting as a dehydrating material. Further, alkali metals and alkaline earth metals react with oxygen to change to hydroxides and to react with water to change into oxides, so that they act not only as dehydrating materials but also as deoxidizing materials. Thereby, the deterioration of the functional layer and the like can be effectively prevented, and the reliability of the device can be improved.

In addition, it is preferable that each of the light emitting units is driven in a matrix by a polysilicon TFT formed by a low-temperature process.
Further, in the above-described method for manufacturing a display device, the functional layer is preferably formed by an inkjet method. In the ink-jet method, a thin film can be formed by patterning a solution in which a material such as a light-emitting layer is dissolved into a desired region, so that material is less wasted than in the case of pattern formation by mask evaporation, which is advantageous in cost. It becomes. Further, since the thin film formation region can be arbitrarily changed by a program, there is an advantage that it is possible to cope with small-quantity production of various kinds.

According to another aspect of the invention, an electronic apparatus includes the above-described electroluminescence device.
According to this configuration, it is possible to provide an electronic device including a highly reliable display unit.

[First Embodiment]
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. In FIGS. 1 to 21, the scale of each layer and each member is shown differently from the actual one in order to make each layer and each member large enough to be recognized in the drawings.

FIG. 1 is a schematic plan view showing a wiring structure of an organic EL display device which is an example of the electroluminescence device of the present embodiment.
As shown in FIG. 1, the electroluminescence device 1 of the present embodiment includes a plurality of scanning lines 101, a plurality of signal lines 102 extending in a direction intersecting the scanning lines 101, and extending in parallel with the signal lines 102. The plurality of power lines 103 are respectively wired. An area defined by the scanning lines 101 and the signal lines 102 is configured as a pixel area.

  The data line driving circuit 104 including a shift register, a level shifter, a video line, and an analog switch is connected to the signal line 102. Further, the scanning line 101 is connected to a scanning side driving circuit 105 including a shift register and a level shifter.

  In each pixel region, a switching thin film transistor 112 for supplying a scanning signal to a gate electrode via the scanning line 101 and a holding device for holding a pixel signal shared from the signal line 102 via the switching thin film transistor 112 A capacitor cap, a driving thin film transistor 123 to which a pixel signal held by the holding capacitor cap is supplied to a gate electrode, and a power supply line when electrically connected to the power supply line 103 via the driving thin film transistor 123. A pixel electrode 111 into which a drive current flows from 103 and a functional layer 110 sandwiched between the pixel electrode 111 and the cathode 12 are provided. The light emitting portion A is configured by the electrode 111, the counter electrode 12, and the functional layer 110, and the display device 1 includes a plurality of the light emitting portions A in a matrix.

  According to such a configuration, when the scanning line 101 is driven and the switching thin film transistor 112 is turned on, the potential of the signal line 102 at that time is held in the storage capacitor cap, and the driving is performed according to the state of the storage capacitor cap. ON / OFF state of the thin film transistor 123 is determined. Then, a current flows from the power supply line 103 to the pixel electrode 111 through the channel of the driving thin film transistor 123, and further, a current flows to the cathode 12 through the functional layer 110. The functional layer 110 emits light according to the amount of current flowing therethrough.

FIG. 2 is a schematic plan view of the present display device, and FIG. 3 is a schematic cross-sectional view of FIG. 2 taken along the line II ′.
As shown in FIG. 3, in the display device 1 of the present embodiment, the circuit element unit 14 and the display element unit 10 are sequentially laminated on the substrate 2, and the substrate surface on which the laminate is formed is sealed by the sealing unit 3. It has a stopped structure. The display element section 10 includes a light emitting element section 11 including a light emitting layer 110b, and a cathode 12 formed on the light emitting element section 11. The cathode 12 and the sealing portion 3 have translucency, and the display device 1 is configured as a so-called top emission type display device in which display light emitted from the light emitting layer is emitted from the sealing portion 3 side. ing.

As the substrate 2, any of a transparent substrate (or a translucent substrate) and an opaque substrate can be used. Examples of the transparent or translucent substrate include, for example, glass, quartz, resin (plastic, plastic film) and the like. In particular, an inexpensive soda glass substrate is suitably used. Examples of the opaque substrate include, for example, a thermosetting resin, a thermoplastic resin, and the like, in addition to a ceramic sheet such as alumina or a metal sheet such as stainless steel subjected to an insulation treatment such as surface oxidation. As shown in FIG. 2, the substrate 2 is divided into a display area 2a located at the center and a non-display area 2b located at the periphery of the substrate 2 and surrounding the display area 2a.
The display area 2a is an area formed by the light emitting units A arranged in a matrix, and a non-display area 2b is formed outside the display area. In the non-display area 2b, a dummy display area 2d adjacent to the display area 2a is formed.

As shown in FIG. 3, the circuit element section 14 includes the above-described scanning lines, signal lines, storage capacitors, switching thin film transistors, driving thin film transistors 123, and the like, and is disposed in the display area 2a. The light emitting unit A is driven.
One end of the cathode 12 is connected from the light emitting element section 11 to the cathode wiring 12 a formed on the substrate 2, and one end 12 b of this wiring is connected to the wiring 5 a on the flexible substrate 5. The wiring 5a is connected to a driving IC 6 (driving circuit) provided on the flexible substrate 5 (see FIG. 2).

The above-described power supply lines 103 (103R, 103G, 103B) are wired in the non-display area 2b of the circuit element section 14.
The above-described scanning-side drive circuits 105 are arranged on both sides of the display area 2a in FIG. The scanning side driving circuits 105 are provided in the circuit element section 14 below the dummy area 2d. Further, in the circuit element section 14, a drive circuit control signal wiring 105a and a drive circuit power supply wiring 105b connected to the scanning side drive circuits 105, 105 are provided.
Further, an inspection circuit 106 is arranged above the display area 2a in FIG. With this inspection circuit 106, quality and defects of the display device can be inspected during manufacturing or at the time of shipment.

  The sealing section 3 includes a sealing resin 603 applied to the substrate 2 and a sealing can (sealing member) 604. The sealing resin 603 is an adhesive for bonding the substrate 2 and the sealing can 604, and is annularly applied around the substrate 2 by, for example, a microdispenser or the like. The sealing resin 603 is made of a thermosetting resin or an ultraviolet curable resin, and is particularly preferably made of an epoxy resin which is a kind of the thermosetting resin. The sealing resin 603 is made of a material that does not easily pass oxygen or moisture, and prevents water or oxygen from entering the inside of the sealing can 604 from between the substrate 2 and the sealing can 604. Alternatively, oxidation of the light emitting layer 110b formed in the light emitting element portion 11 is prevented. In addition, a sealing can 604 made of a light-transmitting member such as glass or resin has a recess 604 a for housing the display element 10 inside thereof, and is joined to the substrate 2 via the sealing resin 603. .

  FIG. 4 shows an enlarged view of the cross-sectional structure of the display area 2a in the present display device. The display device 1 includes a circuit element portion 14 in which a circuit such as a TFT is formed on a substrate 2, a pixel electrode 111, a light emitting element portion 11 in which a functional layer 110 including a light emitting layer 110b is formed, and a cathode. 12 are sequentially laminated.

  In this display device, light emitted from the light emitting layer 110b toward the sealing portion 3 is emitted above the sealing can 604 (on the observer side), and light emitted from the light emitting layer 110b toward the substrate 2 is emitted. The light is reflected by the pixel electrode 111 and emitted to the sealing portion 3 side (observer side). For this reason, a structure in which a transparent conductive material such as ITO or IZO is laminated on a metal having a low work function, such as Ca or Ba, having a film thickness that does not hinder light transmission, is used for the cathode 12. In addition, a light-reflective conductive member is used for the pixel electrode 111. For example, a metal having a work function of 4.6 eV or more, such as gold, silver, copper, chromium, tantalum, or titanium, or a stacked film of these metals is used. It is preferable to use a metal reflective film having a reflectance. Thereby, the light emitted to the substrate 2 side can be efficiently emitted to the sealing portion 3 side. The pixel electrodes 111 are formed by patterning into a substantially rectangular shape in plan view, and a plurality of the pixel electrodes 111 are provided in a matrix in the display area 2a.

  In the circuit element section 14, a base protective film 2c made of a silicon oxide film is formed on the substrate 2, and an island-shaped semiconductor film 141 made of polycrystalline silicon (polysilicon) is formed on the base protective film 2c by a low-temperature process. Is formed. In the semiconductor film 141, a source region 141a and a drain region 141b are formed by high-concentration P ion implantation. Note that a portion where P is not introduced is a channel region 141c.

  Further, a gate insulating film 142 covering the base protective film 2c and the semiconductor film 141 is formed in the circuit element portion 14, and a gate electrode 143 (scanning) made of Al, Mo, Ta, Ti, W or the like is formed on the gate insulating film 142. A line 101) is formed, and a transparent first interlayer insulating film 144a and a second interlayer insulating film 144b are formed on the gate electrode 143 and the gate insulating film 142. The gate electrode 143 is provided at a position corresponding to the channel region 141c of the semiconductor film 141. In addition, contact holes 145 and 146 connected to the source and drain regions 141a and 141b of the semiconductor film 141 are formed through the first and second interlayer insulating films 144a and 144b.

The pixel electrode 111 is patterned and formed in a predetermined shape on the second interlayer insulating film 144b, and one contact hole 145 is connected to the pixel electrode 111.
Further, the other contact hole 146 is connected to the power supply line 103.

In this way, the driving thin film transistor 123 connected to each pixel electrode 111 is formed in the circuit element section 14. In the thin film transistor 123, high brightness and high definition display can be realized because polysilicon is used for the semiconductor film 141. In addition, since this polysilicon is formed by a low-temperature process, an inexpensive glass substrate can be used as the substrate 2.
Note that the above-described storage capacitor cap and the switching thin film transistor 142 are also formed in the circuit element section 14, but these are not shown in FIG.

  The light emitting element section 11 mainly includes a functional layer 110 stacked on each of the plurality of pixel electrodes 111 and a bank layer 112 provided between each pixel electrode 111 and the functional layer 110 to partition each functional layer 110. It is configured. The cathode 12 is disposed on the functional layer 110, and the pixel electrode 111, the functional layer 110 and the cathode 12 constitute a light emitting unit A.

  The bank layer 112 is made of a resist having excellent heat resistance and solvent resistance, such as an acrylic resin or a polyimide resin, and has openings 112 d corresponding to positions where the pixel electrodes 111 are formed. The thickness of the bank layer 112 is preferably, for example, in the range of 0.1 to 3.5 μm, and particularly preferably about 2 μm. When the thickness is less than 0.1 μm, the bank layer 112 is thinner than the total thickness of the hole injection / transport layer and the light emitting layer described later, and the light emitting layer may overflow from the opening 112d, which is not preferable. On the other hand, if the thickness exceeds 3.5 μm, the step due to the opening 112 d becomes large, and it becomes impossible to secure the step coverage of the cathode 12 formed on the bank layer 112, which is not preferable. Further, it is more preferable that the thickness of the bank layer 112 be 2 μm or more, since the insulation from the driving thin film transistor 123 can be increased.

  In each region partitioned by the bank layer 112, the electrode surface 111a of the pixel electrode 111 has been subjected to lyophilic treatment by plasma treatment using oxygen as a processing gas, and exhibits lyophilicity. On the other hand, the surface of the wall surface of the opening 112d and the upper surface 112f of the bank layer 112 are fluorinated (liquid-repellent) by plasma treatment using methane tetrafluoride as a processing gas, and exhibit liquid repellency.

The functional layer 110 includes a hole injection / transport layer 110a stacked on the pixel electrode 111, and a light emitting layer 110b formed adjacent to the hole injection / transport layer 110a. Note that another functional layer having another function may be further formed adjacent to the light-emitting layer 110b. For example, an electron transport layer can be formed.
The hole injection / transport layer 110a has a function of injecting holes into the light emitting layer 110b and a function of transporting holes inside the hole injection / transport layer 110a. As the material for forming the hole injection / transport layer, for example, a mixture of a polythiophene derivative such as polyethylene dioxythiophene and polystyrene sulfonic acid can be used. By providing such a hole injection / transport layer 110a between the pixel electrode 111 and the light emitting layer 110b, the device characteristics such as the light emitting efficiency and the life of the light emitting layer 110b are improved.

  The light emitting layer 110b has three types of a red light emitting layer 110b1 emitting red (R), a green light emitting layer 110b2 emitting green (G), and a blue light emitting layer 110b3 emitting blue (B). The light emitting layers 110b1 to 110b3 are arranged in stripes. As a material of the light emitting layer 110b, for example, (poly) paraphenylenevinylene derivatives, polyphenylene derivatives, polyfluorene derivatives, polyvinylcarbazole, polythiophene derivatives, perylene dyes, coumarin dyes shown in [formula 1] to [formula 5] are used. , Rhodamine-based dyes, or these polymer materials, which are doped with rubrene, perylene, 9,10-diphenylanthracene, tetraphenylbutadiene, Nile Red, coumarin 6, quinacridone, or the like.

  The cathode 12 is made of a light-transmitting conductive member, and is formed on the entire surface of the light emitting element unit 11. Then, it plays a role of flowing a current to the functional layer 110 in a pair with the pixel electrode 111. The cathode 12 has a structure in which, for example, a layer made of a low molecular weight electron injecting material such as calcium (Ca) or magnesium (Mg) and an indium tin oxide (ITO) layer are laminated. In addition, a structure in which a mixed layer (or a laminate) of a magnesium layer and a silver (Ag) layer and an ITO layer may be laminated. Further, an indium zinc oxide (IZO) layer may be stacked instead of the ITO layer. Alternatively, a structure in which an ITO layer, an IZO layer, and the like are omitted and a Ca layer and a gold (Au) layer are simply laminated may be employed.

  At this time, it is preferable that a cathode having a low work function be provided on the side closer to the light emitting layer 110b. In this embodiment, in particular, the cathode closer to the light emitting layer side is in direct contact with the light emitting layer 110b. Plays the role of injecting electrons into The thickness of the electron injection cathode such as Ca is preferably about 5 to 10 nm. If it is less than 10 nm, sufficient light transmittance cannot be secured, and if it is less than 5 nm, sufficient electron injection ability cannot be exhibited.

Further, depending on the material of the light emitting layer, LiF may form LiF between the light emitting layer 110 and the cathode 12 depending on the material of the light emitting layer. The red and green light emitting layers 110b1 and 1110b2 are not limited to lithium fluoride, and may be made of another material. Therefore, in this case, a layer made of lithium fluoride may be formed only on the blue (B) light emitting layer 110b3, and a layer other than lithium fluoride may be stacked on the other red and green light emitting layers 110b1 and 110b2. Further, the cathode 12 may be formed on the red and green light emitting layers 110b1 and 110b2 without forming lithium fluoride.
Note that a protective layer for preventing oxidation made of SiO, SiO ₂ , SiN or the like may be provided on the cathode 12.

Further, a getter material 13 for absorbing or removing oxygen or moisture is formed on the cathode 12 at a position to be an upper layer of the bank layer 112. The getter material 13 includes an alkali metal such as Li, Na, Rb and Cs, an alkaline earth metal such as Be, Mg, Ca, Sr and Ba, an oxide of an alkaline earth metal, an alkali metal or an alkaline earth metal. At least one of the following hydroxides is preferably contained.
The alkaline earth metal oxide reacts with water to change to a hydroxide, thereby acting as a dehydrating material. Alkali metals and alkaline earth metals react with oxygen to change to hydroxides and to react with water to change to oxides, so they act not only as dehydrating materials but also as deoxidizing materials. Thereby, the deterioration of the light emitting section A is effectively prevented, and the reliability of the device can be improved.

  It is preferable to use an opaque material for the getter material 13. Alternatively, it is preferable that the thickness of the getter material 13 is formed to reduce the light transmittance of the getter material 13. This can prevent color bleeding due to light emitted from the adjacent light emitting units A, and can enhance display contrast.

Next, a method for manufacturing the display device of the present embodiment will be described with reference to the drawings.
The manufacturing method of the display device 1 of the present embodiment includes, for example, (1) a bank layer forming step, (2) a plasma processing step, (3) a hole injection / transport layer forming step (including a first droplet discharging step), It comprises (4) a light emitting layer forming step (including a second droplet discharging step), (5) a cathode and getter material forming step, and (6) a sealing step. The manufacturing method is not limited to this, and other steps may be omitted or added as necessary.

(1) Bank Layer Forming Step The bank layer forming step is a step of forming a bank layer 112 having an opening 112d at a predetermined position on the substrate 2. Hereinafter, a forming method will be described.
First, as shown in FIG. 5, an element having a circuit element portion 14 such as a scanning line, a signal line, and a thin film transistor 123 on a substrate 2 and a plurality of pixel electrodes 111 formed on interlayer insulating films 144a and 144b. Prepare a substrate.
Then, a heat-resistant and solvent-resistant photosensitive material such as an acrylic resin or a polyimide resin is applied on the substrate 2, and an opening 112 d is formed in a region where the pixel electrode 111 is arranged by a photolithography technique ( See FIG. 6). Note that the thickness of the bank layer 112 is preferably in the range of 0.1 to 3.5 μm, and particularly preferably about 2 μm. The reason for such a range is as follows.

  That is, if the thickness is less than 0.1 μm, the bank layer 112 is thinner than the total thickness of the hole injection / transport layer and the light emitting layer described later, and the light emitting layer 110b may overflow from the opening 112d, which is not preferable. . On the other hand, when the thickness exceeds 3.5 μm, a step due to the opening 112d becomes large, and it becomes impossible to secure the step coverage of the cathode 12 in the opening 112d. Further, it is preferable that the thickness of the bank layer 112 be 2 μm or more, since the insulation between the cathode 12 and the driving thin film transistor 123 can be increased.

(2) Plasma Treatment Step The plasma treatment step is performed for the purpose of activating the surface of the pixel electrode 111 and further treating the surface of the bank layer 112. In particular, in the activation step, cleaning of the pixel electrode 111 and adjustment of the work function are mainly performed. Further, a lyophilic treatment on the surface of the pixel electrode 111 and a lyophobic treatment on the surface of the bank layer 112 are performed.
This plasma processing step includes, for example, (2) -1 preheating step, (2) -2 activation processing step (a lyophilic step for making lyophilic), (2) -3 lyophobic processing step, and (2) -4 cooling process. It is to be noted that the present invention is not limited to such steps, and steps may be reduced and further steps may be added as necessary.

FIG. 7 shows a plasma processing apparatus used in the plasma processing step.
The plasma processing apparatus 50 illustrated in FIG. 7 includes a pre-heating processing chamber 51, a first plasma processing chamber 52, a second plasma processing chamber 53, a cooling processing chamber 54, and a transfer that transfers the substrate 2 to each of the processing chambers 51 to 54. And a device 55. Each of the processing chambers 51 to 54 is radially arranged around the transfer device 55.

First, a schematic process using these devices will be described.
The preheating step is performed in the preheating processing chamber 51, and heats the substrate 2 transported from the bank layer forming step to a predetermined temperature.
After the preheating step, a lyophilic step and a lyophobic treatment step are performed. That is, the substrate 2 is sequentially transported to the first and second plasma processing chambers 52 and 53, and the bank processing is performed on the bank layer 112 in each of the processing chambers 52 and 53 to make the bank layer lyophilic. After the lyophilic treatment, a lyophobic treatment is performed. After the lyophobic treatment, the substrate 2 is transported to a cooling processing chamber, and the substrate 2 is cooled to room temperature in the cooling processing chamber 54. After this cooling step, the substrate 2 is transferred by the transfer device 55 to the next step of forming a hole injection / transport layer.

Hereinafter, each step will be described in detail.
(2) -1 Preheating Step The preheating step is performed in the preheating processing chamber 51. In the processing chamber 51, the substrate 2 including the bank layer 112 is heated to a predetermined temperature.
As a method of heating the substrate 2, for example, a heater is attached to a stage on which the substrate 2 is placed in the processing chamber 51, and a unit is used to heat the substrate 2 for each stage with the heater. It should be noted that other methods can be adopted.
In the preheating chamber 51, the substrate 2 is heated, for example, in a range of 70 ° C to 80 ° C. This temperature is a processing temperature in the next step of the plasma processing, and is intended to eliminate the temperature variation of the substrate 2 by heating the substrate 2 in advance in accordance with the next step.

If the preheating step is not added, the substrate 2 is heated from room temperature to the above temperature, and the temperature is constantly changed during the plasma processing process from the process start to the process end. Become. Therefore, performing the plasma processing while changing the substrate temperature may lead to uneven characteristics. Therefore, preheating is performed to keep the processing conditions constant and to obtain uniform characteristics.
For this reason, in the plasma processing step, when performing the lyophilic step or the lyophobic step while the substrate 2 is mounted on the sample stage in the first and second plasma processing apparatuses 52 and 53, the preheating temperature is reduced. It is preferable that the temperature be substantially equal to the temperature of the sample stage 56 in which the lyophilic process or the lyophobic process is continuously performed.

That is, the plasma processing was continuously performed on a large number of substrates by preheating the substrate 2 to a temperature at which the sample stages in the first and second plasma processing apparatuses 52 and 53 rise, for example, 70 to 80 ° C. Even in this case, the plasma processing conditions immediately after the start of the process and immediately before the end of the process can be made substantially constant. Thereby, the surface treatment conditions between the substrates 2 can be made the same, the wettability of the bank layer 112 with the composition can be made uniform, and a display device having a certain quality can be manufactured.
Further, by preheating the substrate 2 in advance, the processing time in the subsequent plasma processing can be reduced.

(2) -2 Activation Process In the first plasma processing chamber 52, an activation process is performed. The activation processing includes adjustment and control of the work function of the pixel electrode 111, cleaning of the pixel electrode surface, and lyophilic processing of the pixel electrode surface.
As the lyophilic process, a plasma process (O ₂ plasma process) using oxygen as a process gas in an air atmosphere is performed. FIG. 8 is a diagram schematically showing the first plasma processing. As shown in FIG. 8, the substrate 2 including the bank layer 112 is placed on a sample stage 56 having a built-in heater, and a plasma discharge electrode is provided above the substrate 2 with a gap of about 0.5 to 2 mm. 57 is arranged facing the substrate 2. While the substrate 2 is being heated by the sample stage 56, the sample stage 56 is transported at a predetermined transport speed in the direction of the arrow shown in the drawing, during which the substrate 2 is irradiated with oxygen in a plasma state.

The conditions for the O ₂ plasma treatment are, for example, a plasma power of 100 to 800 kW, an oxygen gas flow rate of 50 to 100 ml / min, a plate transfer speed of 0.5 to 10 mm / sec, and a substrate temperature of 70 to 90 ° C. The heating by the sample stage 56 is mainly performed to keep the substrate 2 preheated.
By this O ₂ plasma treatment, as shown in FIG. 9, the lyophilic treatment is performed on the electrode surface 111a of the pixel electrode 111, the wall surface of the opening 112d of the bank layer 112, and the upper surface 112f. By this lyophilic treatment, a hydroxyl group is introduced into each of these surfaces to impart lyophilicity.
In FIG. 9, the portion subjected to the lyophilic treatment is indicated by a dashed line.
The O ₂ plasma treatment not only imparts lyophilicity but also cleans the pixel electrode 111 and adjusts the work function as described above.

(2) -3 Liquid Repellent Treatment Step In the second plasma treatment chamber 53, as a liquid repellent step, a plasma treatment (CF) using a fluoride-containing gas such as tetrafluoromethane (carbon tetrafluoride) as a treatment gas in an air atmosphere is performed. ₄ plasma treatment). The internal structure of the second plasma processing chamber 53 is the same as the internal structure of the first plasma processing chamber 52 shown in FIG. That is, the substrate 2 is transported at a predetermined transport speed along with the sample stage while being heated by the sample stage, during which the substrate 2 is irradiated with a processing gas in a plasma state.

The conditions of the CF ₄ plasma treatment are, for example, a plasma power of 100 to 800 kW, a flow rate of tetrafluoromethane gas of 50 to 100 ml / min, a substrate transfer speed of 0.5 to 10 mm / sec, and a substrate temperature of 70 to 90 ° C. The heating by the heating stage is performed mainly for keeping the preheated substrate 2 warm, as in the case of the first plasma processing chamber 52.
Note that the processing gas is not limited to tetrafluoromethane (carbon tetrafluoride), and other fluorocarbon-based gases can be used.

As shown in FIG. 10, the liquid repellency treatment is performed on the wall surface of the opening 112d and the upper surface 112f of the bank layer 112 by the CF ₄ plasma treatment. By this lyophobic treatment, a fluorine group is introduced into each of these surfaces to impart lyophobicity. In FIG. 10, the region exhibiting liquid repellency is indicated by a two-dot chain line.
Note that the electrode surface 111a of the pixel electrode 111 is also slightly affected by the CF ₄ plasma treatment, but has little effect on wettability. In FIG. 10, the region showing lyophilicity is indicated by a dashed line.

(2) -4 Cooling Step In the cooling step, the substrate 2 heated for plasma processing is cooled to a control temperature by using the cooling processing chamber 54. This is a step performed to cool down to the control temperature of the ink jet process (droplet discharging process), which is the subsequent process.
The cooling processing chamber 54 has a plate on which the substrate 2 is arranged, and the plate has a structure in which a water cooling device is built in so as to cool the substrate 2.

  By cooling the substrate 2 after the plasma processing to room temperature or a predetermined temperature (for example, a control temperature for performing an ink jet process), the temperature of the substrate 2 becomes constant in the next hole injection / transport layer forming process. The next step can be performed at a uniform temperature with no temperature change of the substrate 2. Thereby, the material discharged by the discharge means such as the ink jet method can be formed uniformly. For example, when discharging the first composition containing the material for forming the hole injection / transport layer, the first composition can be continuously discharged at a constant volume, and the hole injection / transport layer can be discharged. Can be formed uniformly.

Note that the plasma processing apparatus used in the plasma processing step is not limited to the one shown in FIG. 8, and for example, a plasma processing apparatus 60 as shown in FIG. 11 may be used.
The plasma processing apparatus 60 shown in FIG. 11 includes a pre-heating processing chamber 61, a first plasma processing chamber 62, a second plasma processing chamber 63, a cooling processing chamber 64, and a substrate 2 in each of the processing chambers 61 to 64. , And the processing chambers 61 to 64 are arranged on both sides of the transfer device 65 in the transfer direction (both sides in the direction of the arrow in the figure).

In the plasma processing apparatus 60, similarly to the plasma processing apparatus 50 shown in FIG. 8, the substrate 2 transported from the bank layer forming step is transferred to the pre-heating processing chamber 61, the first and second plasma processing chambers 62 and 63, After sequentially transporting the substrate 2 to the cooling processing chamber 64 and performing the same processing as described above in each processing chamber, the substrate 2 is transported to the next hole injection / transport layer forming step.
The plasma device may be a device under vacuum, instead of a device under atmospheric pressure.

(3) Hole injection / transport layer forming step In the light emitting element forming step, a hole injection / transport layer is formed on the pixel electrode 111.
In the hole injection / transport layer forming step, the first composition containing the hole injection / transport layer forming material is discharged onto the electrode surface 111a using, for example, an ink jet device as the droplet discharge (first droplet discharge step). ). After that, a drying process and a heat treatment are performed to form a hole injection / transport layer 110 a on the pixel electrode 111.
Subsequent processes including the hole injection / transport layer forming process are preferably performed in an atmosphere free of water and oxygen. For example, the treatment is preferably performed in an inert gas atmosphere such as a nitrogen atmosphere or an argon atmosphere.

The manufacturing method by the inkjet is as follows.
As shown in FIG. 12, the first composition 110c including the hole injection / transport layer forming material is discharged from a plurality of nozzles formed in the inkjet head H1. Here, the composition 110c is filled in each opening 112d by scanning the inkjet head, but it is also possible to scan the substrate 2. Further, the composition 110c can be filled by relatively moving the inkjet head H1 and the substrate 2. The above points are the same in the subsequent steps performed using the inkjet head H1.

  The ejection by the inkjet head H1 is as follows. That is, the discharge nozzle H2 formed on the ink jet head H1 is disposed so as to face the electrode surface 111a, and the first composition 110c is discharged from the nozzle H2. A bank layer 112 is formed around the pixel electrode 111. The inkjet head H1 faces the electrode surface 111a located in the opening 112d of the bank layer 112, and the inkjet head H1 and the substrate 2 move relatively. While discharging, the first composition droplet 110c having a controlled liquid amount per droplet is discharged from the discharge nozzle H2 onto the electrode surface 111a.

  As the first composition 110c used here, for example, a composition in which a mixture of a polythiophene derivative such as polyethylene dioxythiophene (PEDT) and polystyrene sulfonic acid (PSS) is dissolved in a polar solvent can be used. Examples of the polar solvent include isopropyl alcohol (IPA), normal butanol, γ-butyrolactone, N-methylpyrrolidone (NMP), 1,3-dimethyl-2-imidazolidinone (DMI) and derivatives thereof, and carbitol acetate. And glycol ethers such as butyl carbitol acetate.

More specifically, the composition of the first composition is as follows: PEDT / PSS mixture (PEDT / PSS = 1: 20): 12.52% by weight, PSS: 1.44% by weight, IPA: 10% by weight, NMP: 27 .48% by weight and DMI: 50% by weight. The viscosity of the first composition is preferably about 2 to 20 Ps, and particularly preferably about 4 to 15 cPs.
By using the above-mentioned first composition, stable discharge can be performed without clogging of the discharge nozzle H2.
In addition, the same material may be used for the red (R), green (G), and blue (B) light emitting layers 110b1 to 110b3 as the material for forming the hole injection / transport layer. May be.

As shown in FIG. 12, the discharged first composition droplet 110c spreads on the lyophilic treated electrode surface 111a and fills the opening 112d. Even if the first composition droplet 110c is displaced from the predetermined ejection position and is ejected onto the upper surface 112f, the upper surface 112f is not wetted by the first composition droplet 110c, and the repelled first composition droplet 110c is repelled. Rolls into the opening 112d.
The amount of the first composition discharged onto the electrode surface 111a depends on the size of the opening 112d, the thickness of the hole injection / transport layer to be formed, and the concentration of the hole injection / transport layer forming material in the first composition. Etc. are determined. Further, the first composition droplet 110c may be discharged onto the same electrode surface 111a not only once but also several times. In this case, the amount of the first composition may be the same each time, or the first composition may be changed each time.

  Regarding the structure of the inkjet head, a head H as shown in FIG. 15 can be used. Further, it is preferable to arrange the substrate and the ink jet head as shown in FIG. In FIG. 15, reference numeral H7 denotes a support substrate that supports the inkjet head H1, and a plurality of inkjet heads H1 are provided on the support substrate H7.

  On the ink ejection surface of the inkjet head H1 (the surface facing the substrate 2), a plurality of ejection nozzles (for example, two rows) are arranged in rows along the head length direction and in two rows at intervals in the head width direction. 180 nozzles per row, for a total of 360 nozzles). In addition, the inkjet head H1 has the ejection nozzles directed toward the substrate 2 and is arranged in a row along the substantially X-axis direction while being inclined at a predetermined angle with respect to the X-axis (or the Y-axis), and in the Y direction. A plurality of (six in one row in FIG. 15, a total of twelve in FIG. 15) are positioned and supported on a substantially rectangular support plate 20 in a state of being arranged in two rows at intervals.

  In the ink jet apparatus shown in FIG. 16, reference numeral 1115 denotes a stage on which the substrate 2 is placed, and reference numeral 1116 denotes a guide rail for guiding the stage 1115 in the X-axis direction (main scanning direction) in the figure. Further, the head H can be moved in the Y-axis direction (sub-main scanning direction) in the figure by the guide rail 1113 via the support member 1111. Further, the head H can rotate in the θ-axis direction in the drawing, and can tilt the inkjet head H1 at a predetermined angle with respect to the main scanning direction. Thus, by arranging the inkjet head at an angle to the scanning direction, the nozzle pitch can be made to correspond to the pixel pitch. Further, by adjusting the tilt angle, it is possible to correspond to any pixel pitch.

The substrate 2 shown in FIG. 16 has a structure in which a plurality of chips are arranged on a mother substrate. That is, one chip area corresponds to one display device. Here, three display areas 2a are formed, but the present invention is not limited to this. For example, when applying the composition to the left display area 2a on the substrate 2, the head H is moved to the left side in the figure via the guide rail 1113, and the substrate 2 is moved through the guide rail 1116 in the figure. The coating is performed by moving the substrate 2 upward and scanning the substrate 2. Next, the composition is applied to the display area 2a at the center of the substrate by moving the head H to the right in the figure. The same applies to the display area 2a at the right end.
The head H shown in FIG. 15 and the ink jet device shown in FIG. 16 may be used not only in the hole injection / transport layer forming step but also in the light emitting layer forming step.

Next, a drying step as shown in FIG. 13 is performed to evaporate the polar solvent contained in the first composition to precipitate a material for forming a hole injection / transport layer. This drying process is performed, for example, in a nitrogen atmosphere at room temperature with a pressure of, for example, about 133.3 Pa (1 Torr). If the pressure is too low, the first composition droplets 110c are undesirably bumped. If the temperature is higher than room temperature, the evaporation rate of the polar solvent increases, and a flat film cannot be formed.
After the drying treatment, it is preferable to remove the polar solvent and water remaining in the hole injection / transport layer 110a by performing a heat treatment of heating at 200 ° C. for about 10 minutes in nitrogen, preferably in vacuum.
Most of the hole injection / transport layer 110a formed in this way dissolves in the light emitting layer 110b to be applied in a later step, but a part thereof is formed as a thin film between the hole injection / transport layer 110a and the light emitting layer 110b. To remain. Accordingly, the energy barrier between the hole injecting / transporting layer 110a and the light emitting layer 110b can be lowered to facilitate the movement of holes, and the luminous efficiency can be improved.

(4) Light Emitting Layer Forming Step The light emitting layer forming step includes a surface modifying step, a light emitting layer forming material discharging step (second droplet discharging step), and a drying step.
The surface modification step is performed in order to improve the adhesion between the hole injection / transport layer 110a and the light emitting layer 110b and the uniformity of film formation. That is, in the light emitting layer forming step, the solvent of the second composition used in forming the light emitting layer is insoluble in the hole injection / transport layer 110a in order to prevent the hole injection / transport layer 110a from being redissolved. Use a suitable non-polar solvent. However, on the other hand, the hole injecting / transporting layer 110a has a low affinity for the nonpolar solvent, so that even if the second composition containing the nonpolar solvent is ejected onto the hole injecting / transporting layer 110a, the hole There is a possibility that the injection / transport layer 110a and the light emitting layer 110b cannot be brought into close contact with each other, or the light emitting layer 110b cannot be uniformly applied. Therefore, in order to increase the affinity of the surface of the hole injecting / transporting layer 110a with the nonpolar solvent and the material for forming the light emitting layer, it is preferable to perform a surface modification step before forming the light emitting layer.

In the surface modification step, the same solvent as the non-polar solvent of the second composition used for forming the light emitting layer or a surface modifier that is similar to the non-polar solvent is applied by an inkjet method (droplet discharge method), a spin coating method, or the like. This is performed by applying the solution on the hole injection / transport layer 110a by dipping and then drying.
In the application by the ink-jet method, as shown in FIG. 14, an ink-jet head H3 is filled with a surface modifying material 110d, and the surface-modifying material 110d is discharged from a discharge nozzle H4 formed in the ink-jet head H3. Similarly to the above-described hole injection / transport layer forming step, the discharge nozzle H4 is opposed to the substrate 2 (that is, the substrate 2 on which the hole injection / transport layer 110a is formed), and the inkjet head H3 and the substrate 2 are relatively positioned. This is performed by discharging the surface modifying material 110d from the discharge nozzle H4 onto the hole injection / transport layer 110a while moving.

  In the application by the spin coating method, the substrate 2 is placed on, for example, a rotary stage, and the surface modifier 110d is dropped on the substrate 2 from above, and then the substrate 2 is rotated to deposit the surface modifier 110d on the substrate 2. The hole injection / transport layer 110a is spread over the whole. Although the surface modifier 110d temporarily spreads on the liquid-repellent upper surface 112f, it is blown off by centrifugal force due to rotation and is applied only on the hole injection / transport layer 110a.

  Further, the application by the dipping method is performed by dipping the substrate 2 in, for example, the surface modifying material 110d and then pulling up the substrate 2 to spread the surface modifying material 110d over the entire hole injection / transport layer 110a. In this case as well, the surface modifying material 110d temporarily spreads on the liquid repellent-treated upper surface 112f, but when pulled up, the surface modifying material 110d is repelled from the upper surface 112f and applied only to the hole injection / transport layer 110a. Is done.

As the surface modifier 110d used here, as the same nonpolar solvent as the second composition, for example, cyclohexylbenzene, dihydrobenzofuran, trimethylbenzene, tetramethylbenzene, etc. can be exemplified. Examples of the non-polar solvent include toluene, xylene and the like.
In particular, when applying by an ink-jet method, it is preferable to use dihydrobenzofuran, trimethylbenzene, tetramethylbenzene, cyclohexylbenzene, or a mixture thereof, particularly the same solvent mixture as the second composition, or the like. In the case of the dipping method, toluene, xylene and the like are preferable.

Next, as shown in FIG. 17, the application area is dried. In the drying step, when the coating is performed by the ink jet method, it is preferable that the substrate 2 is placed on a hot plate and heated at a temperature of, for example, 200 ° C. or less to be dried and evaporated. In the case of the spin coating method or the dipping method, it is preferable that the substrate 2 is dried by spraying nitrogen onto the substrate 2 or rotating the substrate to generate an air current on the surface of the substrate 2.
The application of the surface modifying material 110d is performed after the drying treatment in the hole injecting / transporting layer forming step, and after the coated surface modifying material is dried, the hole injecting / transporting layer forming step is performed. Heat treatment may be performed.

By performing such a surface modification step, the surface of the hole injecting / transporting layer 110a becomes easily compatible with the nonpolar solvent, and in a subsequent step, the second composition including the light emitting layer forming material is injected into the hole injecting / transporting layer 110a. / Can be uniformly applied to the transport layer 110a.
The above-mentioned compound 2 or the like generally used as a hole transporting material is dissolved in the surface modifying material 110d to form a composition, and this composition is applied on the hole injecting / transporting layer by an inkjet method. By drying by drying, a very thin hole transport layer may be formed on the hole injection / transport layer 110a.
Most of the hole injecting / transporting layer 110a dissolves in the light emitting layer 110b applied in a later step, but part of the hole injecting / transporting layer 110a remains in a thin film between the hole injecting / transporting layer 110a and the light emitting layer 110b. The energy barrier between the hole injecting / transporting layer 110a and the light emitting layer 110b can be lowered to facilitate the movement of holes and improve luminous efficiency.

Next, as a light emitting layer forming step, the second composition containing the light emitting layer forming material is discharged onto the hole injecting / transporting layer 110a by an ink jet method (droplet discharging method), and then dried to form a hole. The light emitting layer 110b is formed on the injection / transport layer 110a.
FIG. 18 shows an ejection method using ink jet. As shown in FIG. 18, the inkjet head H5 and the substrate 2 are relatively moved, and a discharge nozzle H6 formed in the inkjet head H5 is used to emit a color (for example, blue (B) in this case) containing a light emitting layer forming material. The two compositions 110e are discharged.

  At the time of ejection, the ejection nozzle is opposed to the hole injection / transport layer 110a located in the opening 112d, and the ink jet head H5 and the substrate 2 are moved relative to each other while the ink jet head H5 and the substrate 2 are moved relative to each other. 2 Dispense the composition. As for the amount of liquid discharged from the discharge nozzle H6, the amount of liquid per droplet is controlled.

Examples of the light emitting layer forming material include polyfluorene-based polymer derivatives represented by [Chemical Formula 1] to [Chemical Formula 5], (poly) paraphenylenevinylene derivatives, polyphenylene derivatives, polyvinylcarbazole, polythiophene derivatives, perylene dyes, and coumarin dyes. , A rhodamine-based dye, or the above polymer, doped with an organic EL material. For example, it can be used by doping rubrene, perylene, 9,10-diphenylanthracene, tetraphenylbutadiene, Nile Red, coumarin 6, quinacridone, or the like.
As the non-polar solvent, a solvent that is insoluble in the hole injection / transport layer 110a is preferable, and for example, cyclohexylbenzene, dihydrobenzofuran, trimethylbenzene, tetramethylbenzene, or the like can be used.
By using such a nonpolar solvent for the second composition of the light emitting layer 110b, the second composition can be applied without redissolving the hole injection / transport layer 110a.

  As shown in FIG. 18, the discharged second composition 110e spreads on the hole injection / transport layer 110a and fills the opening 112d. On the other hand, on the liquid-repellent upper surface 112f, even if the first composition droplet 110e is displaced from the predetermined discharge position and is discharged on the upper surface 112f, the upper surface 112f does not get wet with the second composition droplet 110e. The second composition droplet 110e rolls into the opening 112d.

The amount of the second composition 110e discharged onto each hole injection / transport layer 110a depends on the size of the opening 112d, the thickness of the light emitting layer 110b to be formed, the concentration of the light emitting layer material in the second composition, and the like. It is determined.
Further, the second composition 110e may be discharged onto the same hole injection / transport layer 110a not only once but also several times. In this case, the amount of the second composition may be the same each time, or the amount of the second composition 110e may be changed each time.

Next, when the second composition has been discharged to a predetermined position, the discharged second composition droplet 110e is subjected to a drying treatment to evaporate the non-polar solvent contained in the second composition. As a result, a light emitting layer forming material is deposited, and a blue (B) light emitting layer 110b3 as shown in FIG. 19 is formed. Although only one light emitting layer that emits blue light is shown in FIG. 19, the light emitting elements are originally formed in a matrix, as is clear from FIG. 2 and other drawings, and are not shown. Many light emitting layers (corresponding to blue) are formed.
Subsequently, as shown in FIG. 20, a red (R) light emitting layer 110b1 is formed by using the same steps as in the case of the blue (B) light emitting layer 110b3 described above, and finally, a green (G) light emitting layer 110b2 is formed. I do.

Note that the order of forming the light emitting layer 110b is not limited to the order described above, and may be formed in any order. For example, it is possible to determine the order of formation according to the light emitting layer forming material.
In the case of blue 110b3, the second composition of the light emitting layer is dried in a nitrogen atmosphere at room temperature at a pressure of about 133.3 Pa (1 Torr) for 5 to 10 minutes. If the pressure is too low, the second composition 110e is undesirably bumped. On the other hand, if the temperature is higher than room temperature, the evaporation rate of the nonpolar solvent increases, and a large amount of the light emitting layer forming material adheres to the wall surface of the upper opening 112d, which is not preferable.

In the case of the green light emitting layer 110b2 and the red light emitting layer 110b1, it is preferable to dry quickly because of the large number of components of the light emitting layer forming material. Is good.
As other drying means, a far-infrared ray irradiation method, a high-temperature nitrogen gas spraying method and the like can be exemplified.
Thus, the hole injection / transport layer 110a and the light emitting layer 110b are formed on the pixel electrode 111.

(5) Cathode and Getter Material Forming Step In the counter electrode and getter material forming step, first, as shown in FIG. 21, the cathode 12 is formed on the entire surface of the light emitting layer 110b and the bank layer 112. The cathode 12 may be formed by laminating a plurality of materials. For example, it is preferable to form a material having a small work function on the side close to the light emitting layer. For example, it is possible to use Ca, Ba, or the like. There is also. Further, a material having a higher work function than the lower side (substrate side) can be used for the upper side (sealing side).

These cathodes 12 are preferably formed by, for example, an evaporation method, a sputtering method, a CVD method, or the like, and particularly preferably formed by an evaporation method in that damage to the light emitting layer 110b due to heat can be prevented.
Further, lithium fluoride may be formed only on the light emitting layer 110b, and can be formed corresponding to a predetermined color. For example, it may be formed only on the blue (B) light emitting layer 110b3. In this case, the upper cathode layer 12b made of calcium contacts the other red (R) light emitting layer and green (G) light emitting layer 110b1 and 110b2.

  Next, an alkali metal such as Li, Na, Rb, or Cs, or an alkaline earth such as Be, Mg, Ca, Sr, or Ba is provided on the counter electrode 12 at a position on the counter electrode 12 that is to be an upper layer. A getter material 13 containing at least one of a metal, an oxide of an alkaline earth metal, and a hydroxide of an alkali metal or an alkaline earth metal is formed. The getter material is mask-patterned by a vapor deposition method, a sputtering method, a CVD method, or the like. This getter material 13 is preferably an opaque material. Alternatively, it is preferable that the thickness of the getter material 13 is formed to reduce the light transmittance of the getter material 13.

(6) Sealing Step The sealing step is a step of arranging the sealing can 604 on the front surface of the substrate 2 on which the light emitting element is formed, and sealing the periphery of the substrate 2 and the sealing can 604 with the sealing resin 603. It is. By this step, the sealing portion 3 is formed on the substrate 2.
The sealing step is preferably performed in an atmosphere of an inert gas such as nitrogen, argon, or helium. If the operation is performed in the air, if a defect such as a pinhole occurs in the cathode 12, water, oxygen, or the like may enter the cathode 12 from the defective portion and oxidize the cathode 12, which is not preferable.

  Further, by connecting the cathode 12 to the wiring 5a of the substrate 2 illustrated in FIGS. 2 and 3 and connecting the wiring of the circuit element section 14 to the drive IC 6, the display device 1 of the present embodiment is obtained.

  Therefore, in the electroluminescent device of the present embodiment, since the getter material 13 is provided in the display area 2a, even if the area of the non-display area 2b is reduced due to the narrowing of the frame, the arrangement area of the getter material 13 is equal to or more than a certain value. Can be secured. Thereby, intrusion of oxygen or moisture into the light emitting portion A can be effectively prevented, and higher luminance and longer life of the display device can be achieved. Further, since the getter material 13 is arranged in a region (non-light-emitting region) between the light emitting portions A that does not contribute to display, the display quality is not impaired by the getter material 13.

In addition, since the getter material 13 can be accurately arranged in the non-light-emitting region by the mask patterning method, a region where the arrangement region of the getter material 13 and the light-emitting region where the light-emitting layer 110b is formed planarly overlaps can be minimized. , A bright display can be realized.
Furthermore, since the getter material 13 having low transparency is disposed in the non-light emitting region, the getter material 13 functions as a light shielding layer, and can prevent color blur between colored lights emitted from the adjacent light emitting portions A. it can. Thereby, a display with high contrast can be realized.

  Further, in this embodiment, since the hole injection / transport layer 110a and the light emitting layer 110b are formed by the inkjet method, a display device can be manufactured at low cost with less waste of material. That is, in the ink jet method, a thin film made of the above-described material can be formed by patterning a solution in which a predetermined material is dissolved into a desired region. And is advantageous in terms of cost. Further, since the thin film formation region can be arbitrarily changed by a program, there is an advantage that it is possible to cope with small-quantity multi-type production.

[Second embodiment]
Next, a second embodiment of the present invention will be described with reference to the drawings. In the following description, the same parts as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be partially omitted.
In the present embodiment, the formation position of the getter material 13 in the first embodiment is modified, and the getter material is formed on the sealing portion side. That is, the getter material 605 is provided on the inner surface side of the sealing can 604 at a position facing the non-light-emitting region.
The getter material 605 is made of an alkali metal such as Li, Na, Rb, or Cs, an alkaline earth metal such as Be, Mg, Ca, Sr, or Ba, an oxide of an alkaline earth metal, an alkali metal or an alkaline earth metal. A material including at least one of a hydroxide and a pattern formed on the outermost surface of the sealing can 604 by using a vacuum deposition method using a photolithography technique or a mask, a sputtering method, a CVD method, or the like. I have.
The rest is the same as in the first embodiment, and a description thereof will be omitted.

  Therefore, even in the electroluminescence device of the present embodiment, the arrangement area of the getter material can be secured to a certain value or more without deteriorating the display quality. Further, in the present display device, since the getter material 605 is provided on the sealing portion 3 side, the light emitting portion A is not damaged in the step of forming the getter material 605.

[Electronics]
Next, an example of an electronic apparatus including the above-described electroluminescent device will be described.
FIG. 23 is a perspective view illustrating a configuration of a mobile personal computer (information processing device) including the display device according to the above-described embodiment. In the figure, a personal computer 1100 includes a main body 1104 having a keyboard 1102, and a display unit having the above-described electroluminescent device 1106. Therefore, an electronic device including a highly reliable display portion can be provided.

Note that the present invention is not limited to the above-described embodiment, and can be implemented with various modifications without departing from the spirit of the present invention.
For example, in the above-described embodiment, the configuration in which the getter material is provided on either the substrate 2 side or the sealing portion 3 side is illustrated. However, the getter material may be disposed on both the substrate 2 and the sealing portion 3. is there.
In the above embodiment, the getter material is formed only in the non-light-emitting area in the display area 2a, but the getter material may be provided in both the non-light-emitting area and the non-display area 2b.
Furthermore, in the above embodiment, the case where the R, G, and B light emitting layers 110b are arranged in stripes has been described. However, the present invention is not limited to this, and various arrangement structures can be adopted. For example, in addition to the stripe arrangement as shown in FIG. 24A, a mosaic arrangement as shown in FIG. 24B or a delta arrangement as shown in FIG.

In the above embodiment, the example in which the organic EL material is used for the light emitting layer 110b is described. However, the present invention is applied to a device in which the inorganic EL material is used for the light emitting layer 110b (that is, an inorganic EL display device). Of course, it is possible.
Furthermore, in the above-described embodiment, each light emitting portion A is formed in a region partitioned by the partition 112. However, a partition that separates each light emitting portion A is not necessarily required. The material should just be arrange | positioned in the area | region between the adjacent light emitting parts A in planar view.
Further, in the above-described embodiment, the example in which the electroluminescent device of the present invention is used as a display device is described. However, the present invention is applied to other uses, for example, an electroluminescent device for a light source of a liquid crystal display device, or an optical writing type. The present invention is also applicable to laser printers and light sources used for optical communication.

FIG. 2 is a diagram illustrating a wiring structure of the display device according to the first embodiment of the present invention. FIG. 3 is a plan view of the display device. It is II 'sectional drawing of FIG. It is sectional drawing which shows the principal part of a display device. FIG. 7 is a process diagram illustrating a method for manufacturing the display device. FIG. 7 is a process diagram illustrating a method for manufacturing the display device. FIG. 3 is a diagram illustrating a plasma processing apparatus used for manufacturing the display device. FIG. 7 is a schematic diagram showing an internal structure of a first plasma processing chamber of the plasma processing apparatus shown in FIG. FIG. 7 is a process diagram illustrating a method for manufacturing the display device. FIG. 7 is a process diagram illustrating a method for manufacturing the display device. FIG. 7 is a schematic plan view illustrating another example of the plasma processing apparatus used for manufacturing the display device. FIG. 7 is a process diagram illustrating a method for manufacturing the display device. FIG. 7 is a process diagram illustrating a method for manufacturing the display device. FIG. 7 is a process diagram illustrating a method for manufacturing the display device. FIG. 3 is a plan view showing a head used for manufacturing the display device. FIG. 3 is a plan view showing an inkjet device used for manufacturing the display device. FIG. 7 is a process diagram illustrating a method for manufacturing the display device. FIG. 7 is a process diagram illustrating a method for manufacturing the display device. FIG. 7 is a process diagram illustrating a method for manufacturing the display device. FIG. 7 is a process diagram illustrating a method for manufacturing the display device. FIG. 7 is a process diagram illustrating a method for manufacturing the display device. It is a sectional view showing the display of a 2nd embodiment of the present invention. FIG. 13 is a diagram illustrating an example of an electronic apparatus according to the invention. FIG. 3 is a schematic plan view showing the arrangement of light emitting layers.

Explanation of reference numerals

DESCRIPTION OF SYMBOLS 1 ... Electroluminescent device, 2 ... Substrate, 2a ... Display area, 2b ... Non-display area, 3 ... Sealing part, 12 ... Cathode (2nd electrode), 13 , 605: getter material, 110: functional layer, 110b: light emitting layer, 111: pixel electrode (first electrode), 112: bank layer (partition wall), 123: thin film transistor (Switching element), 604: sealing can (sealing member), A: light emitting unit

Claims (11)

A first electrode, a functional layer including a light-emitting layer, and a substrate in which a plurality of light-emitting portions in which a transparent second electrode is sequentially stacked from a lower layer side are provided in a plane;
A transparent sealing member that is disposed to face the first substrate and that can accommodate the light emitting unit;
In a space sealed by the substrate and the sealing member, a getter material for absorbing or removing oxygen or moisture is provided,
The electroluminescent device, wherein the getter material is disposed in a region between adjacent light emitting units in a plan view. The substrate has a partition that partitions the light emitting units,
The electroluminescent device according to claim 1, wherein the getter material is provided at a position on an upper layer side of the partition wall on an outermost surface of the substrate.   The electroluminescent device according to claim 1, wherein the getter material is provided on an outermost surface of the sealing member so as to face a region between the adjacent light emitting units.   The getter material includes at least one of an alkali metal, an alkaline earth metal, an oxide of an alkaline earth metal, a hydroxide of an alkali metal or an alkaline earth metal, silica gel, and a zeolite compound. The electroluminescent device according to claim 1, wherein   The electroluminescent device according to claim 1, wherein the getter material is formed by any one of a vacuum deposition method, a sputtering method, and a CVD method.   The electroluminescent device according to any one of claims 1 to 5, wherein the getter material is dispersed in a liquid and formed by an inkjet method. A switching element is provided corresponding to each of the light emitting units,
7. The electroluminescence device according to claim 1, wherein the switching element is a polysilicon TFT formed by a low-temperature process.   An electronic device comprising the electroluminescent device according to claim 1. Forming a plurality of first electrodes on the substrate;
Forming a partition on the substrate to partition the first electrodes;
A step of forming a functional layer including a light-emitting layer in each region partitioned by the partition wall by an inkjet method,
Forming a transparent second electrode on the functional layer;
A step of forming a getter material for absorbing or removing oxygen or moisture at a position on the upper layer side of the partition wall on the outermost surface of the substrate,
Disposing a transparent sealing member facing the substrate surface on the side where the second electrode is formed, and sealing a space between the substrate and the sealing member. A method for manufacturing an electroluminescence device. A plurality of first electrodes are formed on a substrate, partitions are formed on the substrate to partition the first electrodes, and a functional layer including a light-emitting layer is formed in each of the regions partitioned by the partitions by an inkjet method. Forming a transparent second electrode on the functional layer;
A step of forming a getter material for absorbing or removing oxygen or moisture at a position of the transparent sealing member facing the region where the partition wall is formed,
Positioning the sealing member with respect to the substrate so that the getter material is disposed in the formation region of the partition wall in plan view, and sealing a space between the substrate and the sealing member. And a method for manufacturing an electroluminescence device. The method according to claim 9, wherein the functional layer is formed by an inkjet method.

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