JP4380319B2 - Vapor deposition apparatus and organic electroluminescence element manufacturing method - Google Patents

Description

  The present invention relates to a vapor deposition apparatus and a method for manufacturing an organic electroluminescence (hereinafter referred to as organic EL) element, and more specifically, vapor deposition in which an evaporation material is emitted from a crucible and the evaporation material is deposited on a deposition substrate through a mask. The present invention relates to an apparatus and a method for manufacturing an organic EL element including a step of forming an organic EL film using the vapor deposition apparatus.

  In recent years, as a flat display device, an organic EL element using a light emitting element (hereinafter referred to as “organic EL display”) has been attracting attention. This organic EL display is a self-luminous type flat display that does not require a backlight, and has an advantage that a wide viewing angle peculiar to the self-luminous type can be realized. In addition, an organic EL display is advantageous in comparison with a backlight type (for example, a liquid crystal display) in terms of power consumption because only necessary pixels need to be lit, and high definition that is expected to be put to practical use in the future. It is considered to have sufficient response performance for high-speed video signals.

  The organic layer in the organic EL element is usually formed by laminating 3 to 5 layers such as a hole injection layer, a hole transport layer, a light emitting layer, and a charge injection layer. However, the organic material forming each layer has low water resistance and cannot use a wet process. Therefore, when forming an organic layer, it is common to form each layer in order by a vacuum deposition technique, which is one of vacuum thin film forming techniques, to form a laminated structure. In the case of configuring an organic EL element that performs full-color image display, organic layers made of three kinds of organic materials corresponding to R (red), G (green), and B (blue) color components are different from each other. It is necessary to form a film at the pixel position.

  As a technique for forming such an organic layer, the inventors of the present application have provided an apparatus and a method for continuously forming a plurality of organic layers by relatively moving a substrate to be formed and a plurality of line-type evaporation sources. (For example, refer to Patent Document 1).

  Further, in a line-type evaporation source of a vapor deposition apparatus for vapor-depositing an organic EL material, a metal vapor deposition mask is used for the purpose of limiting a range (pixel) for vapor-depositing the organic EL material on the substrate. For this reason, when the vapor deposition mask passes through the upper part of the line type evaporation source heated by the heat source, the vapor deposition mask rises in temperature by receiving radiation heat from the upper surface of the heated crucible (opposite surface to the substrate). Become. Therefore, if the temperature rise of the vapor deposition mask is large, the expansion coefficient also increases, and the range in which the organic EL material is vapor-deposited is shifted. For this reason, in order to suppress the radiant heat from the line-type evaporation source, a reflector is used.

Japanese Unexamined Patent Publication No. 2003-157773 (Japanese Patent Application No. 2002-133536, paragraphs 0026-0030, FIGS. 1 and 2)

  However, as shown in FIG. 4, since the radiation blocking plate 115 is disposed in the vicinity of the crucible 112, it is exposed to a high temperature. Therefore, although it is necessary to cool the radiation blocking plate 115 such as water cooling, the organic EL material evaporated to the radiation blocking plate opening 116 strikes the radiation blocking plate 116 and adheres to the holes 114 of the crucible 112. There is a problem in that it hinders the flight of the organic EL material scattered from. If the radiation blocking plate opening 116 is widened to a range where it does not adhere, the exposed portion of the surface of the crucible 112 facing the vapor deposition mask (not shown) spreads, reducing the effect of preventing radiant heat, and radiant heat is applied to the vapor deposition mask. It will be transmitted. Even if the amount of adhesion is very small, when the vapor deposition apparatus is operated for a long time, the organic EL material is laminated, which also hinders the scattered organic EL material.

The vapor deposition apparatus of the present invention is a vapor deposition apparatus for depositing a vapor deposition material evaporated on a vapor deposition substrate through a vapor deposition mask, and a crucible for storing and vaporizing the vapor deposition material, and the crucible facing the vapor deposition substrate. a plurality of protrusions longitudinally formed on the crucible in a state of protruding upward, and holes formed in each of the projecting portions toward said more internal crucible in the vapor-deposited substrate direction, around the protrusion in and comprising a radiation blocking member provided at a top surface and a distance of the crucible at a position lower than the exit side opening of the exit side opening with the same height or the hole of the hole.

Method of manufacturing an organic electroluminescent device of the present invention, by using the vapor deposition apparatus depositing evaporated organic material onto the substrate through a deposition mask, comprising the step of forming an organic film constituting the organic electroluminescence element Tei The vapor deposition apparatus includes a crucible for storing and evaporating the vapor deposition material, a protruding portion formed in a longitudinal direction of the crucible in a state of protruding from the crucible upper portion facing the deposition target substrate, and the crucible inside More holes formed in each of the protrusions toward the deposition substrate, and the height around the protrusion and the same as the emission side opening of the hole or lower than the emission side opening of the hole and a radiation blocking member provided at a top surface and a distance of the crucible in the position.

  In the above vapor deposition apparatus, by forming a hole for injecting the vapor deposition material evaporated in the crucible in the protruding portion provided at the upper part of the crucible, the radiation blocking body is the same height as the emission side opening of the hole or the emission side opening of the hole. It can provide in a position lower than a part. For this reason, the problem of adhesion of the vapor deposition material to the radiation blocker during vapor deposition can be solved. Thereby, the radiation blocker can be cooled, the influence of thermal radiation on the vapor deposition mask can be reduced, and the temperature rise of the mask can be suppressed. Thereby, the thermal expansion of a vapor deposition mask can be suppressed and there exists an advantage that the shift | offset | difference of the vapor deposition range of the evaporated vapor deposition material can be prevented exactly.

  In the method of manufacturing an organic electroluminescence element, an organic film constituting the organic EL element is formed using the vapor deposition apparatus of the present invention, so that the vapor deposition mask is formed by the radiation blocker without hindering the flight of the vaporized vapor deposition material. Since radiant heat can be prevented, the expansion of the vapor deposition mask can be suppressed. Therefore, it becomes possible to form an organic film constituting the organic EL element without causing pixel shift, so that the pixel aperture ratio as designed can be obtained, thereby ensuring the luminance of the organic EL display device. There is an advantage that you will be able to.

  Vapor deposition material evaporated to the target substrate through the vapor deposition mask for the purpose of reducing the influence of radiant heat from the crucible of the vaporization source to the vapor deposition mask and suppressing the expansion of the vapor deposition mask. In a vapor deposition apparatus for depositing, a crucible for storing and evaporating a vapor deposition material, a projecting portion formed in a state of projecting to the upper part of the crucible facing the deposition target substrate, and projecting from the crucible inside toward the deposition target substrate And a radiation blocking body provided around the protrusion and spaced from the upper surface of the crucible at the same height as the exit side opening of the hole or lower than the exit side opening of the hole And realized.

A first embodiment of the vapor deposition apparatus of the present invention will be described with reference to FIG. The vapor deposition apparatus according to the present embodiment is mainly suitable for manufacturing an organic EL element, and uses a line type evaporation source having a long evaporation source, and the line type evaporation source and a substrate to be evaporated the a is relatively moved but performs a et deposition. FIG. 1A is a schematic perspective view showing the main part of the vapor deposition apparatus according to the present embodiment, and FIG. 1B is a schematic sectional view showing the structure of the evaporation source.

  As shown in FIG. 1A, a vapor deposition source 11 is provided. For example, the evaporation source 11 is a so-called line-type evaporation source. Details of the evaporation source 11 will be described later. A deposition target substrate 51 is installed above the evaporation source 11 through a deposition mask 31. The deposition target substrate 51 is a glass substrate, for example, and an organic EL material is vacuum deposited as an example. In this vapor deposition apparatus, the relative position between the evaporation source 11 and the evaporation target substrate 51 is varied so that the evaporation target portion of the evaporation target substrate 51 passes through the region where the evaporation material evaporated from the evaporation source 11 scatters. A moving device is provided. While moving the deposition target substrate 51 and the deposition mask 31 adhered to the deposition target substrate 51 in the direction of arrow A by this moving device, the organic material is evaporated from the evaporation source 11 toward the deposition target surface of the deposition target substrate 51 to form a film. I do. The evaporation source 11 may be moved by a moving device (not shown) while the evaporation target substrate 51 and the evaporation mask 31 are fixed.

  Next, the structure of the evaporation source of the vapor deposition apparatus according to the present embodiment will be described in detail with reference to FIG. As shown in FIG. 1 (2), a crucible 12 is provided for storing and evaporating the vapor deposition material 71. The crucible 12 is made of a material having good thermal radiation efficiency, such as carbon, titanium, and tantalum, and is a heat-resistant container for containing the evaporation material 71. The crucible 12 is disposed along the deposition target substrate surface 51 and relative to the moving device. It is formed so that the direction orthogonal to the variable direction of the position is the longitudinal direction of the crucible. A heat source 21 for heating the crucible 12 and evaporating the evaporation material 71 is installed below the crucible 12. The heat source 21 is a heater composed of, for example, a heating wire, and the temperature can be controlled by a temperature measuring device and a temperature controller.

  In the crucible 12, a plurality of projecting portions 13 are formed, for example, in the longitudinal direction of the crucible so as to project to the upper part of the crucible facing the deposition target substrate 51. The outer shape of the projecting portion 13 may project from the crucible upper surface 12u, such as a columnar shape, a truncated cone shape, or a truncated pyramid shape. It is sufficient that the protruding height is equal to or higher than the upper surface of the radiation blocking body 15 when the radiation blocking body 15 described in detail later is provided. The height of the protrusion 13 is, for example, about 5 mm to 10 mm from the upper surface 12u of the crucible. In the protruding portion 13, a hole 14 having a shape that is tapered stepwise from the inside of the crucible toward the deposition target substrate 51 is formed. Therefore, the crucible 12 has a structure in which the inside is sealed except for the hole 14.

  Further, a radiation blocking body 15 is provided around the protrusion 13 and at the same height as the exit side opening 14a of the hole 14 or at a position lower than the exit side opening 14a with a gap d from the crucible upper surface 12u. It has been. The radiation blocker 15 is a plate-shaped member made of a metal material such as stainless steel or aluminum alloy, and is made of a material having higher heat reflection efficiency than the material of the crucible 12. In order to increase the heat reflection efficiency, it is preferable that the crucible 12 side is processed into a mirror surface. Further, a rib (not shown) that reinforces the strength of the radiation blocking body 15 formed in a plate shape may be formed on the radiation blocking body 15.

  In the above embodiment, one radiation blocking body 15 is provided above the crucible 12, but a plurality of radiation blocking bodies 15 may be arranged in a layer structure. For example, the plurality of radiation blocking bodies 15 can be arranged in a layered structure at intervals. Thus, the radiation heat of the crucible 12 may be blocked more efficiently by arranging a plurality of radiation blocking bodies 15 in a layered structure.

  In the above vapor deposition apparatus, the radiation blocking body 15 is spaced from the crucible upper surface 12u around the protrusion 13 and at the same height as the exit side opening 14a of the hole 14 or lower than the exit side opening 14a of the hole 14. Therefore, the vapor deposition material 71 ejected from the hole 14 can fly in the direction of the deposition target substrate 51 (in the direction of arrow A) without adhering to the radiation blocker 15. Further, even when the evaporation target substrate 51 is cooled to a temperature lower than that of the crucible 12 by the cooling device, the evaporated evaporation material 71 emitted from the hole 14 does not contact the edge of the opening 15 a of the radiation blocking body 15. Since it flies in the direction of the deposition target substrate 51, the deposition material 71 can be prevented from adhering to the radiation blocker 15.

  Further, since the exposed portion of the surface of the crucible 12 with respect to the vapor deposition mask 31 is reduced, more radiation heat from the crucible 12 to the vapor deposition mask 31 can be blocked. That is, when the crucible 12 is viewed from the deposition substrate 51 side, the radiation blocking body 15 is in a state of covering the upper part of the crucible 12 excluding the protruding portion 13 where the hole 14 is formed, and the crucible 12 viewed from the deposition substrate 51 side. The exposure is minimal. Therefore, the radiant heat from the crucible 12 is shielded by the radiation blocker 15, and adverse effects on the vapor deposition mask 31 can be prevented.

  Further, since the hole 14 for injecting the vapor deposition material 71 evaporated from the inside of the crucible 12 has a shape that gradually tapers from the inside of the crucible 12 toward the deposition target substrate 51, the vapor deposition evaporated in the crucible 12. This does not hinder the material 71 from being scattered toward the exit side opening 14 a of the hole 14.

  Moreover, in the said vapor deposition apparatus 1, it is preferable to provide the cooling device 71 in the radiation blocker 15, as shown in FIG. In addition, although the cross section of the radiation blocking body 15 shown in this drawing is L-shaped, it may be T-shaped. The drawing shows an example in which cooling bodies 72 are provided on both sides of the radiation blocking body 15 in order to efficiently cool the radiation blocking body 15.

The basic configuration of the cooling device 71 includes, for example, a cooling body 72 and a refrigerant feeding device 73 provided in contact with the radiation blocking body 15. Moreover, you may provide the temperature control part (not shown) which controls the temperature of the cooling body 72. FIG. Cooling body 7 2, for example aluminum, an aluminum alloy, a metal material such as stainless steel, and its inside in which flow passage through which coolant circulates is formed. As the refrigerant fed into the flow path by the refrigerant feeding device 73, for example, cold water or a cooling gas (carbon dioxide gas, nitrogen gas, etc.) can be used. The coolant is fed from the crucible 12 to the vapor deposition mask 31 by setting the temperature of the radiation blocking body 15 to be lower than the temperature of the crucible 12 by flowing the coolant through the flow path provided in the cooling body 72 by the coolant feeding device 73. The effect of heat radiation can be further reduced.

  Next, the Example which concerns on the manufacturing method of the organic EL element of this invention is described below with operation | movement of a vapor deposition apparatus.

  As shown in FIG. 1, the evaporation source 11 is heated by the heat source 21 while the temperature is controlled, so that the vapor deposition material 71 (for example, organic EL material) in the crucible 12 is melted and evaporated, passes through the holes 14, The light is emitted upward. Then, it is deposited on the deposition surface of the deposition substrate 51. At that time, the evaporation target substrate 51 above the evaporation source (line evaporation source) 11 is moved in a predetermined direction, and the shape of the opening of the evaporation mask 31 is formed on the evaporation target surface of the evaporation target substrate 51 passing above the evaporation source 11. An organic EL thin film is formed so as to transfer the light.

  Here, the crucible 12 is heated to a high temperature by the heat source 21. When the vapor deposition mask 31 passes over the crucible 12, the vapor deposition mask 31 is heated and expanded by receiving radiation heat from the crucible 12. Therefore, by arranging the radiation blocking body 15 made of a material having a higher heat reflection efficiency than the material of the crucible 12 above the crucible 12 as described above, the influence of the heat radiation from the crucible 12 to the vapor deposition mask 31. Can be reduced.

  In the method for manufacturing an organic electroluminescent element, an organic film constituting the organic electroluminescent element is formed using the vapor deposition apparatus of the present invention, and thus the radiation blocker 15 is not obstructed without inhibiting the flight of the evaporated vapor deposition material 71. Since radiation heat to the vapor deposition mask 31 can be prevented, expansion of the vapor deposition mask 31 can be suppressed. Therefore, since the organic EL film can be formed without causing pixel shift, the pixel aperture ratio as designed can be obtained, thereby ensuring the luminance of the organic EL display device. become.

  Next, a second embodiment according to the vapor deposition apparatus of the present invention will be described with reference to the schematic sectional view of FIG. In FIG. 3, the vapor deposition source of a vapor deposition apparatus is shown.

  As shown in FIGS. 3 (1), (2), (3) and (4), a crucible 12 for storing and evaporating the vapor deposition material 71 is provided. The crucible 12 is a heat-resistant container that is made of a material having good thermal radiation efficiency, such as carbon, titanium, or tantalum, and that contains the evaporation material 71. A heat source 21 for heating the crucible 12 and evaporating the evaporation material 71 is installed below the crucible 12. The heat source 21 is a heater composed of, for example, a heating wire, and the temperature can be controlled by a temperature measuring device and a temperature controller.

  In the crucible 12, a protruding portion 13 is formed so as to protrude to the upper part of the crucible facing the deposition target substrate 51. The outer shape of the projecting portion 13 may project from the crucible upper surface 12u, such as a columnar shape, a truncated cone shape, or a truncated pyramid shape. It is sufficient that the protruding height is equal to or higher than the upper surface of the radiation blocking body 15 when the radiation blocking body 15 described in detail later is provided. The height of the protrusion 13 is, for example, about 5 mm to 10 mm from the upper surface 12u of the crucible. In the protruding portion 13 shown in (1), a hole 14 having a shape that is tapered stepwise and partially continuously from the inside of the crucible 12 toward the deposition target substrate is formed. In the protrusion 13 shown in (2), a hole 14 having a shape that continuously tapers from the inside of the crucible 12 toward the deposition target substrate is formed. In the protrusion 13 whose outer shape shown in (3) is frustoconical, a hole 14 having a shape that tapers linearly from the inside of the crucible 12 toward the deposition substrate is formed. Or the hole 14 may be linearly formed in the protrusion part 13 whose outer shape shown in (4) is cylindrical from the inside of the crucible 12 toward the deposition target substrate. Therefore, the crucible 12 has a structure in which the inside is sealed except for the hole 14. The continuously tapered portion may be formed of a curved surface or several planes. That is, the shape may be any shape as long as the evaporated vapor deposition material 71 is smoothly guided to the exit side opening 14 a of the hole 14 without adhering to the inside of the hole 14.

  Further, a radiation blocking body 15 is provided around the protrusion 13 and at the same height as the exit side opening 14a of the hole 14 or at a position lower than the exit side opening 14a with a gap d from the crucible upper surface 12u. It has been. The radiation blocker 15 is a plate-shaped member made of a metal material such as stainless steel or aluminum alloy, and is made of a material having higher heat reflection efficiency than the material of the crucible 12. In order to increase the heat reflection efficiency, it is preferable that the crucible 12 side is processed into a mirror surface. Moreover, you may form the rib which reinforces the intensity | strength of the radiation blocking body 15 currently formed in plate shape in the radiation blocking body 15.

  In the second embodiment, one radiation blocking body 15 is provided above the crucible 12, but a plurality of radiation blocking bodies 15 may be arranged in a layer structure. For example, the plurality of radiation blocking bodies 15 can be arranged in a layered structure at intervals. Thus, the radiation heat of the crucible 12 may be blocked more efficiently by arranging a plurality of radiation blocking bodies 15 in a layered structure.

In the vapor deposition apparatus described with reference to FIG. 3, the same operation and effect as the vapor deposition apparatus 1 described with reference to FIG. 1 (2) can be obtained, and the holes 14 are stepped from the inside of the crucible 12 toward the deposition target substrate 51. The vapor deposition material 71 evaporated from the hole 14 of the vapor deposition apparatus 1 described with reference to FIG. 1 (2) is partly continuously or continuously tapered. Can be smoothly scattered. Therefore, the distribution of the evaporated vapor deposition material 71 becomes more uniform. Further, in the shape of the protruding portion 13 shown in FIGS. 3 (2), (3), and (4), the thickness of the tip opening portion of the protruding portion 13 can be formed with the minimum thickness, so that the radiation blocking body 15 is formed. The area of the tip opening portion of the protruding portion 13 exposed to the side is minimized, and the amount of radiant heat from the protruding portion 13 itself can be suppressed to a very small amount , so that an increase in the deposition mask temperature can be suppressed. Therefore, the thermal expansion of the vapor deposition mask is reduced, and the occurrence of vapor deposition position deviation can be suppressed.

  Moreover, the said vapor deposition apparatus can be integrated in an in-line type organic electroluminescent vapor deposition system as an example. Further, the vapor deposition apparatus described in this embodiment is applicable even when a film made of another element or another material is manufactured. In the above embodiment, an example of a long line-type evaporation source has been shown. However, the structure of the protrusion and the radiation blocking body and the structure of the hole can be applied to other evaporation sources. is there.

  The vapor deposition apparatus and the organic EL element manufacturing method of the present invention can be applied even in the case of manufacturing an element other than the organic EL element and a film made of other materials.

BRIEF DESCRIPTION OF THE DRAWINGS It is drawing which shows 1st Example which concerns on the vapor deposition apparatus of this invention, FIG. 1 (1) is a typical perspective view which shows the principal part of the vapor deposition apparatus which concerns on a present Example, (2) The structure of an evaporation source FIG. It is a schematic block diagram which shows the Example of a cooling device. It is schematic structure sectional drawing which shows 2nd Example which concerns on the vapor deposition apparatus of this invention. It is schematic structure sectional drawing which shows the vapor deposition source of the conventional vapor deposition apparatus.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Deposition apparatus, 12 ... Crucible, 13 ... Projection part, 14 ... Hole, 14a ... Ejection side opening part, 15 ... Radiation blocker, 31 ... Deposition mask

Claims (6)

In a vapor deposition apparatus for depositing a vapor deposition material evaporated on a vapor deposition substrate through a vapor deposition mask,
A crucible for containing and evaporating the vapor deposition material;
A plurality of protrusions formed in the longitudinal direction of the crucible in a state of protruding to the upper part of the crucible facing the deposition target substrate;
Holes formed in each of the protrusions from the inside of the crucible toward the deposition substrate,
A radiation blocking body provided around the protrusion and at the same height as the exit side opening of the hole or at a position lower than the exit side opening of the hole and spaced from the upper surface of the crucible.
Vapor deposition equipment . The radiation blocking body is composed of a plate-shaped body made of metal,
The vapor deposition apparatus according to claim 1, further comprising a cooling device that cools the radiation blocking body. The vapor deposition apparatus according to claim 1, wherein the radiation blocking body includes a plurality of layers arranged in a layer structure. The vapor deposition apparatus according to claim 1, wherein the hole has a shape that tapers from the inside of the crucible toward the vapor deposition substrate. A moving device that varies a relative position of the crucible and the deposition substrate so that a deposition position of the deposition substrate passes through a region where the vapor deposition material evaporated from the crucible is scattered;
The crucible is formed so that the direction perpendicular to the variable direction of the relative position by the moving device is the longitudinal direction of the crucible along the deposition target substrate surface,
The vapor deposition apparatus according to claim 1, wherein a plurality of the holes are arranged in a longitudinal direction of the crucible. Using a vapor deposition apparatus for depositing evaporated organic material onto the substrate through a deposition mask, provided with a step of forming an organic film constituting the organic electroluminescent device,
The vapor deposition apparatus includes:
A crucible for containing and evaporating the vapor deposition material;
A plurality of protrusions formed in the longitudinal direction of the crucible in a state of protruding to the upper part of the crucible facing the deposition target substrate;
Holes formed in each of the protrusions from the inside of the crucible toward the deposition substrate,
A radiation blocking body provided around the protrusion and at the same height as the exit side opening of the hole or at a position lower than the exit side opening of the hole and spaced from the upper surface of the crucible.
Manufacturing method of organic electroluminescent element .

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