JP4352379B2 - Manufacturing method and manufacturing apparatus of organic electroluminescence element - Google Patents

Description

  The present invention relates to a manufacturing method and a manufacturing apparatus of an organic electroluminescence (organic EL) element.

  Generally, when forming a thin film of the order of nm to μm, a vacuum deposition method is used. FIG. 16 is a cross-sectional view of a vapor deposition apparatus showing a general vapor deposition method. 51 is a vacuum chamber. A heating source boat 52 is arranged in the vacuum chamber 51. The evaporating material 53 is arranged in the form of powder, bulk or the like in the concave portion at the center of the boat 52. A substrate 54 is disposed above the boat 52 so as to face the boat 52. Then, the inside of the vacuum chamber 51 is evacuated to make a vacuum. The boat 52 is usually made of a resistor such as tungsten or molybdenum, and generates current by flowing current. The evaporation material 53 is heated by the heat generated by the boat 52, and the evaporation material 53 evaporates in the direction of the substrate 54 in the vacuum chamber 51. The evaporated evaporation material 53 flies and accumulates on the surface of the substrate 54 to form a thin film having a uniform thickness. The above is a general resistance heating type vacuum deposition method.

  FIG. 17 is a cross-sectional view of a substrate showing a method for forming a thin film pattern using a general photoresist. The uniform thin film 55 made of the evaporation material 53 is formed on the surface of the substrate 54. A photoresist 56 is applied onto the thin film 55 by substrate spin. The uniformly coated photoresist 56 is exposed and developed with an optical pattern having a desired pattern shape to produce a resist pattern shape. The thin film 55 on the substrate 54 has a portion covered with the photoresist 56 and an exposed portion to be removed. The exposed portions to be removed are removed by etching means such as RIE, ion beam milling, or wet etching, and finally the photoresist 56 is dissolved and removed with a solvent such as an organic material to obtain a desired thin film pattern. The above is a method for forming a thin film pattern using a general photoresist (photolithographic pattern forming method).

  A thin film material to which a general photolithography pattern forming method as shown in FIG. 17 can be applied needs to have water resistance and solvent resistance. Therefore, when a thin film pattern is formed of a material having low water resistance and low solvent resistance, such as a material used for an organic EL element, it is generally performed by a vacuum mask vapor deposition method or the like.

  For example, a pattern formation method (vacuum mask vapor deposition method) disclosed in Japanese Patent Laid-Open No. 10-321372 (Patent Document 1) relates to an organic EL display panel having a plurality of light emitting portions and a method for manufacturing the same. The organic EL display panel described in Patent Document 1 protrudes from one surface of the substrate so as to expose the substrate, the plurality of first electrodes formed on one surface side of the substrate, and a portion of the first electrode, and to cover the other portion. A plurality of electrically insulating partition walls formed on the exposed portion of the first electrode, an organic EL medium layer formed on each of the exposed portions of the first electrode, and a plurality of second electrodes formed on the organic EL medium layer. And a recess is formed in the protruding upper portion of the partition wall.

Further, in the method for manufacturing an organic EL display panel described in Patent Document 1, in the light emitting layer forming step, a mask having a plurality of openings exposing only a desired portion of the exposed first electrode is mounted on the protruding upper portion of the partition wall. Then, an organic light emitting layer of a predetermined color is deposited through the opening, and then the mask is moved so that the opening exposes an undeposited portion of the organic light emitting layer, and the same process is repeated for each color, and then The cathode layer is formed on the entire surface.
Japanese Patent Laid-Open No. 10-321372

  In a full-color organic EL element, it is necessary to combine fine elements (pixels) emitting red, green, and blue to form one pixel. However, the pattern formation method in Patent Document 1 has a limit of pattern formation of about several tens of μm. This is because when the pattern is formed on the mask, it is necessary to reduce the thickness of the mask as the pattern becomes finer. When the thickness of the mask is reduced, the mask is bent and a gap is formed between the mask and the substrate. The pigment spreads over a wider range than the mask pattern due to the gap, and the pigment is blurred and blurred.

Moreover, when coating each color light emitting layer separately, it is necessary to perform alignment of the shadow mask and switching of the vapor deposition source, which is troublesome.
Therefore, an object of the present invention is to provide a manufacturing method and a manufacturing apparatus of an organic EL element that can simplify the manufacturing process with high definition.

  In order to solve the above-described problems of the related art, the present invention provides the following methods (a) and (b) for manufacturing an organic EL element and a manufacturing apparatus.

(A) For the first substrate (10) formed with at least a plurality of first electrodes (11) and a light emitting layer (13) in which a blue light emitting dye (14B) is dispersed, A plurality of recesses (22) corresponding to the arrangement of the electrodes and a second substrate (21) in which through holes (23) are formed in each of the plurality of recesses , the first electrode and the recesses correspond to each other. A step of disposing the light emitting layer so as to be in contact with the surface of the second substrate on which the concave portion is formed, and a red light emitting dye (14R) or a green light emitting dye through the through holes in the plurality of concave portions. (14G) is filled with a dye filling step, and the red light emitting dye and the green light emitting dye are heated and evaporated to diffuse the red light emitting dye and the green light emitting dye into the light emitting layer of the first substrate. And the red light emission in the light emitting layer. On the first substrate to the dye and the green luminescent dye has diffused, the method of manufacturing the organic electroluminescent element which comprises a step of forming a second electrode (15).

(B) a first substrate (10) on which at least a plurality of first electrodes (11) and a light emitting layer (13) in which a blue light emitting dye (14B) is dispersed are formed , and the first electrode A plurality of recesses (22) corresponding to the arrangement of the second substrate (21) having a through hole (23) in each of the plurality of recesses, and the plurality of recesses of the second substrate. and placement means for by opposing arranged such that the recess is formed a surface of the second substrate and the light emitting layer is in contact with so as to correspond to the first electrode in the substrate, the said recess Dye filling means for filling the red light emitting dye (14R) or the green light emitting dye (14G) through the through hole, and heating and evaporating the red light emitting dye and the green light emitting dye, and the red light emitting dye and the green light emitting The light emission of the first substrate A dye diffusing means for diffusing in, and a film forming means for forming a second electrode (15) on the first substrate in which the red luminescent dye and the green luminescent dye are diffused in the light emitting layer; An apparatus for manufacturing an organic electroluminescence element, comprising: a substrate transfer means (1) for transferring the first substrate from the arrangement means to the film forming means.

  The production method of the present invention can produce a high-definition organic EL element and can simplify the production process.

  Hereinafter, the manufacturing method of the organic EL element which is one Embodiment of this invention is demonstrated with reference to an accompanying drawing. FIG. 1 is a schematic diagram of the entire apparatus. Broadly speaking, a sheet substrate transport system 1 including a supply roll 2 as a supply unit of the sheet substrate 10 and a winding roll 3 as a winding unit, a luminescent dye diffusion system 20 including a stamp 21 and a heater 25, vapor deposition, It comprises vacuum film forming systems 30 and 31 for performing sputtering.

  As shown in FIG. 2, as the sheet substrate, for example, a sheet TFT substrate 10 in which a TFT (Thin Film Transistor) (not shown) is formed on a sheet using polyethersulfone, polyimide, or the like is used. Can do. As the pixel electrode (anode) 11, in this embodiment, transparent ITO (Indium Tin Oxide) having a high work function is used, and square ones each having a side of 13 μm are arranged on the sheet TFT substrate 10 every 1 μm. Then, as shown in FIG. 3, PEDOT / PSS (poly (3,4-ethylenedioxythiophene)) which is the hole transport layer 12 is about 50 nm thereon, the light emitting layer 13 is about 80 nm, printing method, etc. Was formed.

  The light-emitting layer 13 is most preferably a polymer material in view of easiness of film formation, thermal stability of the film, mechanical stability, and the like, for example, polyvinyl carbazole (PVK) that emits blue-violet light. . The blue light emitting dye 14B is dispersed in this. As the blue light-emitting dye 14B, a coumarin derivative such as coumarin 47, tetraphenylbutadiene, perylene, an iridium complex that emits triplet exciton, or the like can be used. In this embodiment, FIrpic, which is an iridium complex that emits light with high efficiency, was used, and 10 wt% was dispersed in PVK. Since PVK has poor electron transport properties, OXD-7 ({1,3-bis (4-tert-butylphenyl-1,3,4-oxadiazol) -2-yl} benzene), PBD (2- It is desirable to disperse an electron transporting material such as (4-biphenylyl) -5- (4-tert-butyphenyl) -1,3,4-oxadiazole). In the present embodiment, OXD-7 was dispersed by 30 wt%.

  As shown in FIGS. 4A and 5, the stamp 21 forms a stripe pattern composed of the recesses 22 on the surface of a substrate using Si or the like that can be finely processed by a method such as a photolithography method or an etching method. Each through-hole 23 is provided in each recess 22. The stamp 21 may have a drum shape as shown in FIG.

  In order to obtain red, green, and blue light emission with a width of 13 μm every 1 μm using the sheet TFT substrate 10, the width of the recess 22 of the stripe pattern of the stamp 21 is set to 13 μm as shown in FIG. The widths of the convex portions are alternately 1 μm and 15 μm. This is because the blue light emitting dye 14B is dispersed in the light emitting layer 13 as described above, and the red light emitting dye 14R and the green light emitting dye 14G are diffused in the light emitting layer 13 as described later.

The diffusion amount of the luminescent dye under the same diffusion condition increases as the depth of the concave portion decreases, and decreases as it increases. When the evaporation temperatures of the luminescent dyes of the respective colors are different from each other, it is necessary to change the depth of the concave portions of the respective colors to align the optimum diffusion conditions for the respective colors. In the present embodiment, Btp ₂ Ir (acac) (bis [2- (2′benzocyenyl) -pyridinate-N, C ³ ] (acetylacetonate) iridium complex) is used as the red light-emitting dye 14R, and Ir (ppy) is used as the green light-emitting dye 14G. ) ₃ (fac-tri (2-phenylpyridyl) iridium complex), the depth of the red light emitting dye 14R recess was 2 μm, and the depth of the green light emitting dye 14G recess was 3 μm. This depth was determined experimentally.

  As shown in FIG. 6, the through hole 23 is connected to each color, and the tip is connected to each color dye solution container 24R, 24G. Each color solution 14Rs, 14Gs, in which about 1 wt% to several tens wt% of a luminescent dye is dissolved in an organic solvent such as chloroform, toluene, dichlorobenzene, etc., is supplied from the respective color dye solution containers 24R, 24G to the recesses 22 of the stamp 21. Then, the solvent is evaporated at a temperature of about 100 ° C. at which the dye does not evaporate to form a film of several nm to several hundred nm. In this embodiment, a 30 wt% dye solution using chloroform as a solvent was filled from the bottom of the concave groove to a height of 1 μm, the solvent was evaporated, and a film having a thickness of 300 nm was formed. The through hole 23 may be connected in the stamp 21.

  As the luminescent dye, in addition to those used in the present embodiment, neil red, pyran derivatives such as DCM1, squarylium derivatives, porphyrin derivatives, chlorin derivatives, eurodillin derivatives, triplet exciton luminescence are used as the red luminescent dye 14R. An iridium complex, a platinum complex, or the like can also be used. Similarly, a coumarin derivative such as coumarin 6, a quinacridone derivative, an iridium complex that emits triplet exciton, or the like can be used as the green light-emitting dye 14G. Here, the order of forming the respective color light emitting dyes is not particularly limited.

  As shown in FIG. 7, the sheet TFT substrate 10 is transported to a predetermined position facing the stamp 21 in a nitrogen atmosphere (desirably, a dew point of −50 ° C. or less), and each row of the anodes 11 faces the recess 22 of the stamp 21. And place it. Then, as shown in FIG. 8, the sheet TFT substrate 10 and the stamp 21 are brought into contact (contact).

  At this time, the surface of the stamp 21 is only in direct contact with the light emitting layer 13, and the light emitting dyes 14 </ b> R and 14 </ b> G in the recesses do not directly touch the light emitting layer 13. Further, the relationship between the stamp 21 and the sheet TFT substrate 10 in FIGS. Note that the vertical arrangement of the stamp 21 and the sheet TFT substrate 10 is not limited to that shown in FIG.

  As shown in FIG. 8, when the heater 25 in the stamp 21 is used to heat at a predetermined temperature for a predetermined time, the respective color light-emitting dyes 14R and 14G evaporate and reach the light-emitting layer 13, and then the light-emitting layer 13 at that position. Diffuse (dope) in. In this embodiment, the heating temperature and time are 180 ° C. and 5 minutes, respectively. The depths (2 μm, 3 μm) of the respective color recesses of the stamp 21 shown above are the results of adjustment so that this diffusion condition is optimal for each color.

  In the present invention, each color light emitting dye 14R, 14G diffuses into the light emitting layer 13 in which the blue light emitting dye 14B is dispersed. There is an appropriate value for the concentration of each of the 14R and 14G luminescent dyes in the luminescent layer 13, and if it is less than that, the luminescence of the luminescent dye cannot be obtained. However, if the concentrations of the luminescent dyes of 14R and 14G are appropriate, energy transfer occurs from the blue luminescent dye 14B having a short wavelength to the red luminescent dye 14R and the green luminescent dye 14G having a long wavelength. Accordingly, the blue light emitting dye 14B does not emit light in the diffused portion of the red light emitting dye 14R and the green light emitting dye 14G, and light emission of each color can be appropriately obtained. In the present embodiment, the concentration of the luminescent dye sufficient for obtaining light emission was about 1 wt%.

After that, as shown in FIG. 9, the sheet TFT substrate 10 is conveyed in the direction of arrow A and sent to the vacuum deposition film forming tank 30, while the dye diffusion process untreated portion of the continuous sheet TFT substrate 10 is luminescent dye diffusion It is sent onto the stamp 21 of the system 20, and the dye diffusion process described above is performed in that portion. At the same time, in the vacuum deposition film forming tank 30, a substance 15a, for example, Mg, which has a low work function and is suitable for the material of the cathode 15 shown in FIG. _0.9 Ag _0.1 or the like is formed to about 100 nm by vacuum deposition.

  Thereafter, the cathode film forming portion of the sheet TFT substrate 10 is sent to the vacuum sputter film forming tank 31, which uses a moisture-resistant protective material 16a such as silicon nitride and has a predetermined thickness, for example, about 1 μm. A moisture-resistant protective film 16 shown in FIG. 10 is formed. On the other hand, the dye diffusion treatment portion of the continuous sheet TFT substrate 10 is sent from the luminescent dye diffusion system 20 to the vacuum vapor deposition film forming tank 30, and the cathode film forming process is performed. Further, the dye diffusion unprocessed portion of the sheet TFT substrate 10 that is connected is sent onto the stamp 21, and the dye diffusion process is performed on that portion.

  By performing these steps (a dye diffusion step, a cathode film forming step, and a protective film forming step) in order, an organic EL element can be manufactured in order. The produced part is wound into a roll. The organic EL element produced as described above is cut into a desired size and used.

  As shown in FIG. 10, the organic EL element can take out light emission of an arbitrary pixel from the lower surface of the sheet TFT substrate 10 by applying a voltage between an arbitrary anode 11 and a cathode 15. Further, as shown in FIG. 11, the film configuration other than the moisture-resistant protective film can be manufactured in the opposite manner to that of FIG. 10, in which case light is extracted from the upper surface of the sheet TFT substrate 10. In such a case, an opaque sheet TFT substrate can also be used.

In addition, as shown in FIG. 12, a hole injection layer 17 is formed between the anode 11 and the hole transport layer 12, and an electron injection layer 18 and an electron transport layer 19 are formed between the light emitting layer 13 and the cathode 15. It is also possible to improve the luminous efficiency by forming them. Further, as shown in FIG. 13, partition walls 101 such as SiO ₂ are formed by sputtering or the like between the anodes 11 arranged on the sheet TFT substrate 10 in advance, and the stamp 21 emits light from the sheet TFT substrate 10. It is also possible to prevent the surface of the stamp 21 from directly contacting the light emitting layer 13 when it is placed on the layer 13.

  The stamp 21 can also be installed in the vacuum chamber 26 as shown in FIG. In this case, the sheet TFT substrate 10 is first transported into the vacuum chamber 26, and each row of the anodes 11 is placed facing the concave portions 22 of the stamp 21. Further, as shown in FIG. 15, the entire sheet TFT substrate 10 is previously placed in the vacuum chambers 4 and 5, and the sheet TFT substrate 10 is transported to a predetermined position facing the stamp 21, and each row of the anodes 11. Can be placed opposite to the concave portion 22 of the stamp 21.

It is a figure which shows one Embodiment of the organic electroluminescent element manufacturing apparatus which concerns on this invention. It is a figure which shows the sheet | seat board | substrate which concerns on this invention. It is sectional drawing which shows one Embodiment of the sheet | seat board | substrate which concerns on this invention. It is a figure which shows the example of the stamp shape which concerns on this invention. It is sectional drawing which shows one Embodiment of the stamp which concerns on this invention. It is the figure which supplied each color solution to the stamp which concerns on this invention. It is a figure which shows the arrangement | positioning relationship between the stamp which concerns on this invention, and a sheet | seat board | substrate. It is the figure which added the heat by the heater to the luminescent pigment | dye of the stamp recessed part which concerns on this invention. It is an expanded sectional view of the organic electroluminescent element manufacturing apparatus which concerns on this invention. It is a figure which shows one Embodiment of the organic electroluminescent element which concerns on this invention. It is a figure which shows other embodiment of the organic electroluminescent element which concerns on this invention. It is a figure which shows other embodiment of the organic electroluminescent element which concerns on this invention. It is a figure which shows other embodiment of the organic electroluminescent element which concerns on this invention. It is a figure which shows other embodiment of the organic electroluminescent element manufacturing apparatus which concerns on this invention. It is a figure which shows other embodiment of the organic electroluminescent element manufacturing apparatus which concerns on this invention. It is sectional drawing of the vapor deposition apparatus apparatus used for a general vapor deposition method. It is a figure which shows the formation method of the thin film pattern by a general photoresist.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Sheet substrate transport system 2 Supply roll 3 Winding roll 10 Sheet substrate 11 Pixel electrode (anode)
13 Light emitting layer 14R Red light emitting dye 14G Green light emitting dye 14B Blue light emitting dye 15 Cathode 20 Dye diffusion system 21 Stamp 22 Recess 25 Heater 30 Vacuum deposition film forming tank 31 Vacuum sputter film forming film

Claims (2)

Even without small, a plurality of first electrode with respect to the first substrate and the light emitting layer is formed of a blue emitting dye is dispersed, a plurality of recesses and the plurality of corresponding to the arrangement of the first electrode A surface of the light emitting layer and the second substrate on which the concave portion is formed with a second substrate having a through hole formed in each of the concave portions so that the first electrode and the concave portion correspond to each other ; placing such contacts,
A dye filling step of filling the plurality of recesses with a red light emitting dye or a green light emitting dye through the through hole; and
Heating and evaporating the red light emitting dye and the green light emitting dye, and diffusing the red light emitting dye and the green light emitting dye into the light emitting layer of the first substrate;
Forming a second electrode on the first substrate in which the red light emitting dye and the green light emitting dye are diffused in the light emitting layer. A method for producing an organic electroluminescent element, comprising: Even without small, a plurality of first electrodes, a first substrate and a light emitting layer is formed of a blue emitting dye is dispersed,
A plurality of recesses corresponding to the arrangement of the first electrodes, a second substrate having a through hole in each of the plurality of recesses,
The plurality of recesses of the second substrate are opposed to correspond to the first electrode of the first substrate, and the light emitting layer and the surface of the second substrate on which the recesses are formed An arrangement means for arranging to contact ,
A dye filling means for filling the concave portion with a red light emitting dye or a green light emitting dye through the through hole ;
A dye diffusing means for heating and evaporating the red luminescent dye and the green luminescent dye, and diffusing the red luminescent dye and the green luminescent dye into the light emitting layer of the first substrate;
A film forming means for forming a second electrode on the first substrate in which the red light emitting dye and the green light emitting dye are diffused in the light emitting layer;
An apparatus for manufacturing an organic electroluminescent element, comprising: a substrate transfer means for transferring the first substrate from the placement means to the film forming means.

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