JP2019194359A - Vapor deposition apparatus and vapor deposition method and manufacturing method of organic el display device - Google Patents

Abstract

To provide a vapor deposition apparatus suppressing an influence of electromagnetic induction even if an electric magnet is used as a magnet of magnetic chucking, suppressing a defect or a degradation of an element such as TFT formed on a substrate to be vapor deposited, and further a degradation of a property of an organic layer, and a vapor deposition method.SOLUTION: A vapor deposition apparatus is configured to clamp a vapor deposition mask (1) by an electric magnet(3), the electric magnet (3) including a first electric magnet (3A) which generates a magnetic field in a first direction, and a second electric magnet (3B) which generates a magnetic field in a second direction opposite to the first direction. As a result, a magnetic field is weakened by simultaneously operating the first and second electric magnets (3A, 3B) when a current is flown, and then a normal clamping force is obtained by turning off an operation of the second electric magnet thereafter.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a vapor deposition apparatus, a vapor deposition method, and a method for manufacturing an organic EL display apparatus, for example, for vapor-depositing an organic layer of an organic EL display apparatus.

  For example, when an organic EL display device is manufactured, a driving element such as a TFT is formed on a support substrate, and an organic layer is laminated on the electrode corresponding to each pixel. This organic layer is sensitive to moisture and cannot be etched. Therefore, the organic layer is laminated by stacking a support substrate (substrate to be deposited) and a vapor deposition mask and depositing an organic material through the opening of the vapor deposition mask. Then, a necessary organic material is laminated only on the necessary pixel electrode. If the deposition substrate and the deposition mask are not as close as possible, an organic layer is not formed only in an accurate region of the pixel. If the organic material is not deposited only on the accurate pixel area, the display image tends to blur. Therefore, a magnetic chuck that uses a magnetic material for the vapor deposition mask and interposes the vapor deposition substrate between the permanent magnet or electromagnet and the vapor deposition mask is used to bring the vapor deposition substrate and the vapor deposition mask closer (for example, Patent Document 1).

Japanese Patent Laid-Open No. 2008-024956

  Conventionally, a metal mask has been used as a vapor deposition mask. However, in recent years, in order to form a finer opening, a hybrid type vapor deposition mask in which the periphery of the mask opening formed of a resin film is supported by a metal support layer. Tends to be used. An evaporation mask with a small amount of magnetic material, such as a hybrid mask, cannot perform sufficient adsorption unless a stronger magnetic field (magnetic field) is used.

  As described above, if the adsorption is not sufficient, the accessibility between the deposition target substrate and the deposition mask decreases. A strong magnetic field is required to sufficiently attract the vapor deposition mask to the vapor deposition substrate side. When a permanent magnet is used as the magnet of the magnetic chuck, when the magnetic field is strong, it is difficult to align the deposition substrate and the deposition mask. On the other hand, when an electromagnet is used, a magnetic field can be applied after alignment without applying a magnetic field at the time of alignment, which facilitates alignment between the evaporation target substrate and the evaporation mask. However, if a strong magnetic field is applied after the alignment of the deposition substrate and the deposition mask using an electromagnet, performance defects and deterioration of characteristics may occur in the TFT and organic material laminated film of the deposition substrate. The inventor found. In particular, when a hybrid type vapor deposition mask is used, a strong magnetic field is required to perform sufficient adsorption. In this case, the magnetic field to be strengthened is at most about twice as large as a large electromagnet is required. However, even in the case of an electromagnet in the case of a conventional metal mask, the change in magnetic flux when current is applied is very large, and the change in magnetic flux becomes more remarkable as the current increases. The present inventor has found that a defect of a TFT formed on a deposition target substrate and a deterioration of an organic layer can be remarkably caused by the electromagnetic induction generated when the current is applied.

  The present invention has been made to solve such a problem. Even when an electromagnet is used as a magnet of a magnetic chuck, an element such as a TFT formed on a vapor deposition substrate is defective or deteriorated, and further organic. An object of the present invention is to provide a vapor deposition apparatus and a vapor deposition method that suppress the deterioration of the characteristics of the layer.

  Another object of the present invention is to provide a method for producing an organic EL display device having excellent display quality by using the vapor deposition method.

  An evaporation apparatus according to an embodiment of the present invention includes an electromagnet, a substrate holder that is provided at a position facing one magnetic pole of the electromagnet, and holds a deposition substrate, and the deposition substrate that is held by the substrate holder. A vapor deposition mask provided at a position opposite to the surface opposite to the electromagnet and having a magnetic material; a vapor deposition source provided opposite to the vapor deposition mask and vaporizing or sublimating vapor deposition material; and a power supply circuit for driving the electromagnet. The electromagnet includes: a first electromagnet that generates a magnetic field that faces in a first direction; and a second electromagnet that generates a magnetic field in a direction opposite to the first direction. ing.

  The vapor deposition method of one embodiment of the present invention includes an electromagnet, a vapor deposition substrate, and a vapor deposition mask having a magnetic material, and the vapor deposition substrate and the vapor deposition by energizing the electromagnet from a power circuit. A step of adsorbing a mask, and a step of depositing the vapor deposition material on the deposition target substrate by scattering of the vapor deposition material from a vapor deposition source disposed apart from the vapor deposition mask, wherein the electromagnet includes a first A first electromagnet for generating a magnetic field facing in the direction and a second electromagnet for generating a magnetic field in a direction opposite to the first direction, and after the energization of the first and second electromagnets simultaneously, The second electromagnet is turned off.

  An organic EL display device manufacturing method according to an embodiment of the present invention includes forming an organic layer by forming at least a TFT and a first electrode on a support substrate, and depositing an organic material on the support substrate using the evaporation method. And forming a second electrode on the laminated film.

  According to the vapor deposition apparatus and the vapor deposition method of one embodiment of the present invention, it is possible to suppress defects and deterioration of elements such as TFTs formed on a vapor deposition substrate, and further deterioration of characteristics of the organic layer.

It is a figure explaining the structural example of the electromagnet of one Embodiment of this invention. It is a figure explaining the other structural example of the electromagnet of one Embodiment of this invention. It is a figure which shows the relationship between the electromagnet of a vapor deposition apparatus, a to-be-deposited substrate, and a vapor deposition mask. It is an enlarged view of an example of a vapor deposition mask. It is a figure which shows typically the magnetic field generated by an electromagnet. It is a figure which shows typically the magnetic field generated by the conventional electromagnet. It is a figure which shows the relationship between magnetic flux and the space | interval of a to-be-deposited board | substrate and a vapor deposition mask. It is a figure which shows the vapor deposition process by the manufacturing method of the organic electroluminescent display apparatus of this invention. It is a figure which shows the state by which the organic layer was laminated | stacked with the manufacturing method of the organic electroluminescence display of this invention.

  Next, the vapor deposition apparatus and vapor deposition method of one Embodiment of this invention are demonstrated, referring drawings. The overall configuration example of the vapor deposition apparatus of the present embodiment is shown in FIG. 3A, and an example of the structure of the electromagnet 3 is shown in FIG. 1. As shown in FIG. 3A, the electromagnet 3, the substrate holder 29 that holds the deposition substrate 2 to be provided at a position facing one magnetic pole of the electromagnet 3, and the deposition substrate 2 that is held by the substrate holder 29. It includes a vapor deposition mask 1 provided on the surface opposite to the electromagnet 3 and having a magnetic material, and a vapor deposition source 5 provided to face the vapor deposition mask 1 and vaporizes or sublimates the vapor deposition material. Further, as shown in FIGS. 1 and 2, the electromagnet 3 generates a first electromagnet 3 </ b> A that generates a magnetic field (magnetic field) in a first direction and a magnetic field (magnetic field) that is opposite to the first direction. And a second electromagnet 3B.

  Here, in order to obtain adhesion (good accessibility) between the vapor deposition mask 1 and the vapor deposition substrate 2, the present inventor uses a permanent magnet in place of the electromagnet 3 in the configuration as shown in FIG. The permanent magnet, the touch plate 4, the deposition substrate 2 and the deposition mask 1 were overlapped to examine the relationship between the magnetic flux and the gap between the deposition mask 1 and the deposition substrate 2. The result is shown in FIG. In addition, the permanent magnet used the sheet magnet which a magnetic field produced on one surface and a magnetic field did not produce on the other surface (magnetic field is 0). Three permanent magnets having different magnetic fields were prepared, and the three permanent magnets were exchanged to examine the relationship between the magnetic field on the surface of the deposition mask 1 and the gap between the deposition substrate 2 and the deposition mask 1. As the vapor deposition mask 1, a hybrid type mask was used. In addition, from the result of confirming the relationship between the gap and the deposition state of the organic material, it is understood that the gap between the deposition target substrate 2 and the deposition mask 1 is preferably as small as possible, and a desired deposition state can be obtained if it is 3 μm or less. Yes.

  Therefore, the investigation results shown in FIG. 4 show that the larger the magnetic flux density B (B = μH; μ is the magnetic permeability and H is the strength of the magnetic field) of the magnet, the better. However, as described above, the present inventor adsorbs the vapor deposition mask 1 with a strong magnetic field with the electromagnet 3, and when the vapor deposition substrate 2 and the vapor deposition mask 1 are sufficiently brought close to each other, the vapor deposition mask 1 is formed on the vapor deposition substrate 2. It has been found that elements such as TFTs can be damaged, performance can be degraded, and characteristics of the organic layer can be degraded. The present inventor conducted further diligent investigation and investigated the cause, and as a result, when current was supplied to the electromagnetic coil 32 of the electromagnet 3 (hereinafter also referred to as the first electromagnetic coil), the electromotive force caused by electromagnetic induction was applied. It has been found that overcurrent flows in a circuit such as a TFT (not shown) formed on the vapor deposition substrate 2. Then, the inventor destroys or deteriorates the TFT or the organic layer 25 (see FIG. 6) due to the overcurrent or Joule heat generated in the electrode 22 (see FIG. 5 or 6) due to the overcurrent. I found out to do.

That is, for example, as shown in FIG. 3D as an example of the conventional electromagnet 3, when a current is passed through the electromagnetic coil 32 of the electromagnet 3, the magnetic field H is generated in a certain direction by the right-handed screw law. This magnetic field H has a property of adsorbing a magnetic substance. However, when this current is applied, the current flows rapidly (almost instantaneously), and the magnetic flux Φ (Φ = BS = μHS; S is the cross-sectional area of the core 31) generated by the electromagnet 3 rapidly increases. When the magnetic flux Φ changes rapidly, an electromotive force corresponding to V∝−dΦ / dt is generated. When a current is supplied to the electromagnetic coil 32, the time (rise time) Δt until the current reaches a predetermined current from 0 depends on the magnitude of the self-inductance of the electromagnet 3, but in the normal electromagnet 3, it is 10 μs. (Seconds). Since Δt is very small, the minute time dt can be approximated by this Δt. Therefore, for example, if a magnetic flux of about 300 Gauss is changed at this time Δt, an electromotive force of about 30 MV is generated by electromagnetic induction. This electromotive force causes a current to flow through the closed circuit in the deposition target substrate 2 and damages the TFT and the like. The electromotive force V increases as the change in the magnetic flux Φ increases, as can be seen from the above equation. The electromagnetic coil 32 of the electromagnet 3 has a self-inductance, so that the change of the magnetic flux Φ is suppressed. However, the large induced electromotive force of about 30 MV is still generated. It shows that it affects. Further, as the amount Q (J) of Joule heat, heat represented by Q = V ² · t / R is generated (R: electric resistance (Ω) of a closed circuit in the deposition target substrate 2). Due to the generation of Joule heat, organic materials that are weak at high temperatures may deteriorate their properties.

  As a result of further intensive studies by the inventor, the magnetomotive force generated by the electromagnet 3 (N · I; N is the number of turns of the coil and I is the magnitude of the current flowing through the electromagnetic coil 32) gradually increases. It has been found that such a problem can be solved by gradually changing the generated magnetic flux. That is, the change in the magnetic flux B only occurs when the current is applied to the electromagnetic coil 32 of the electromagnet 3 and when the current is turned off. If the current is stabilized, a magnetic field corresponding to the current and the number of turns of the coil is generated. It occurs stably and continues to adsorb magnetic substances. Therefore, the change in the magnetic flux B is only at the time of turning on and off the current, and the time is about 10 μs as described above. For example, if a predetermined current is reached in about 1 ms (millisecond), there is no problem. Does not occur. Therefore, for example, as shown in FIG. 3C, a part of the first electromagnetic coil 32 is wound in the reverse direction, and the first electromagnet 3A and the second electromagnet 3B in the winding direction opposite to the first electromagnet 3A. The present inventor has found that the problem due to the occurrence of electromagnetic induction can be solved by turning off the second electromagnet 3B after supplying current.

Although the predetermined magnetic field H is generated by the first electromagnet 3A, a current also flows through the second electromagnet 3B when the current is input. Since the second electromagnetic coil 35 of the second electromagnet 3B is continuous with the electromagnetic coil 32 of the first electromagnet 3A, a current flows simultaneously. However, the winding direction of the second electromagnetic coil 35 of the second electromagnet 3B is reversed from that of the first electromagnetic coil 32 of the first electromagnet 3A. Therefore, the magnetic field H ₀ generated by the second electromagnet 3B is downward in the figure and opposite to the magnetic field H of the first electromagnet 3A. As a result, the magnetic field H generated by the first electromagnet 3A is canceled, and the generated magnetic field at the time of current application becomes (H−H ₀ ). As described above, the electromotive force due to electromagnetic induction is proportional to the speed of change of the magnetic flux B, that is, the magnetic field H. Therefore, if the magnetic field (H−H ₀ ) decreases, the electromotive force due to electromagnetic induction decreases. As a result, the influence of electromagnetic induction is reduced. Therefore, it is possible to avoid the influence of electromagnetic induction when current is applied.

  For example, if the number of turns of the second electromagnetic coil 35 of the second electromagnet 3B is about half that of the first electromagnet 3A, the generated magnetic field at the time of current application is about half. That is, the electromotive force due to electromagnetic induction is also halved. And the magnetic field H for adsorption | suction of the original vapor deposition mask 1 is obtained by turning off the 2nd electromagnet 3B after input of an electric current. Therefore, there is no influence on the adsorption of the vapor deposition mask 1. The number of turns of the second electromagnetic coil 35 of the second electromagnet 3B may be at most about 1/3 to 2/3 of the number of turns of the electromagnetic coil 32 of the first electromagnet 3A. If reverse electromagnetic induction generated by turning off the second electromagnet 3B becomes a problem, the second electromagnetic coil 35 of the second electromagnet 3B is provided with a plurality of terminals and gradually turned off. You can also

  Further, as shown in FIG. 3C, the second electromagnet 3 </ b> B can be formed without extending the same core 31 as the first electromagnet 3 </ b> A and winding the second electromagnetic coil 35. Insulating the outer periphery of the electromagnetic coil 32 and winding directly, or using the first electromagnet 3A as an air core electromagnet and inserting the second electromagnet 3B with the winding direction reversed, or air core The first electromagnet 3A may be inserted into the inner circumference of the second electromagnet 3B. Hereinafter, the relationship between the two electromagnets 3A and 3B having different magnetic field directions will be described in more detail.

Example 1
The example shown in FIG. 1 has the same configuration as the example shown in FIG. 3C described above, but this example is a cross-sectional view of the electromagnet 3, and the current to the first and second electromagnetic coils 32 and 35 is shown. The direction is indicated by × (downward) and • (upward). Furthermore, in this example, a plurality of terminals 35a, 35b, and 35c are formed in the second electromagnetic coil 35 of the second electromagnet 3B, and the second electromagnet 3B can be gradually reduced by switching the terminals. Since the electric resistances of the first and second electromagnetic coils 32 and 35 are very small, even if the second electromagnetic coil 35 of the second electromagnet 3B is turned off with respect to the voltage of the power supply circuit 6, The current of the 1 electromagnet 3A hardly changes. Therefore, the magnetic field H generated by the first electromagnet 3A can be obtained as it is. On the other hand, when the current is turned on (when the main switch 60 is turned on), the second electromagnetic coil 35 also operates. As described above, since the electromagnetic coil 32 of the first electromagnet 3A and the second electromagnetic coil 35 of the second electromagnet 3B are continuous, the current flows through both simultaneously. However, since the winding direction of the second electromagnetic coil 35 is reverse, a reverse magnetic field H ₀ is generated. Therefore, the magnetic field generated when the current is turned on (when the main switch 60 is turned on) is reduced, and adverse effects due to electromagnetic induction can be prevented.

  Since the number of turns of the second electromagnetic coil 35 is smaller than that of the electromagnetic coil 32 of the first electromagnet 3A, the influence of the reverse electromotive force of the electromagnetic induction that can be generated by turning off the second electromagnet 3B is small. However, if necessary, the influence can be reduced as much as possible by cutting the second electromagnet 3B stepwise. This stepwise OFF is obtained by forming a plurality of terminals 35 a, 35 b, 35 c on the second electromagnetic coil 35 and sequentially switching them by a changeover switch 61 as shown in FIG. The speed when the second electromagnet 3B is turned off is not limited to a short time of μ seconds, and may be, for example, manual switching of a slide switch. To put it in an extreme way, there is no problem even if it takes a time on the order of seconds or minutes. In addition, it is possible to incorporate a circuit for sliding the changeover switch 61 in conjunction with the current input main switch 60.

  For example, as shown in FIG. 1, the cutting of the second electromagnet 3B is performed by forming terminals 35a, 35b, and 35c, and when the current is turned on, the changeover switch 61 is connected to the terminal 35c. The operation of the second electromagnet 3B can be gradually reduced by sliding the terminal connected to the changeover switch 61 with the terminals 35b and 35a after the current is supplied. The number of terminals is not limited to three, and any number can be formed.

  Further, for example, when positioning the deposition target substrate 2 and the deposition mask 1, both the electromagnets 3 </ b> A and 3 </ b> B are operated in a weak magnetic field, and the second electromagnet 3 </ b> B is moved after the setting is completed. It may be cut gradually. By doing so, it is possible to perform alignment in a state in which the deposition target substrate 2 and the deposition mask 1 are brought close to each other to some extent, and accurate alignment is easily performed. In addition, even when a magnetic field is applied after alignment, the magnetic field is gradually applied, and mutual positional deviation is unlikely to occur.

  With such a structure in which the second electromagnets 3B are juxtaposed, even when vapor deposition is completed and the first electromagnet 3A is turned off, the operation opposite to that at the time of current application, that is, switching of the second electromagnet 3B After the switch 61 is sequentially switched from the terminal 35a to the terminal 35c to operate the second electromagnet 3B, the main switch 60 of the power supply circuit 6 can be turned off. By doing so, the magnetic field of the electromagnet 3 can be easily released without being affected by electromagnetic induction even when the deposition target substrate 2 is removed. That is, when the current of the electromagnet 3 is turned off, the same electromagnetic induction problem as that when the current is supplied is likely to occur. However, according to the present embodiment, the problem can be solved.

  In the above example, the core 31 is lengthened to form the second electromagnet 3B. However, as described above, the present invention is not limited to this example. If electrical insulation between the coils is obtained, the first electromagnet 3A Multiple second electromagnetic coils 35 may be wound on the electromagnetic coil 32. Further, the second electromagnet 3B may be formed inside or on the outer periphery of the first electromagnet 3A. In either case, the electromagnetic coil 32 of the first electromagnet 3A and the second electromagnetic coil 35 are preferably connected. This is because current can be applied simultaneously.

(Example 2)
In the example shown in FIG. 1 described above, the first and second electromagnets 3A and 3B are formed by changing the winding direction of the first and second electromagnetic coils 32 and 35 wound around the same core 31. ing. However, two types of electromagnetic coils need not be wound around the same core. For example, as shown in FIG. 2, the first electromagnet 3A (3A1, 3A2) is formed of a plurality of unit electromagnets 3A1, 3A2, and the second electromagnet 3B is formed on a part or the entire outer periphery thereof. May be. In this example, outside the two unit electromagnets 3A1 and 3A2, a third electromagnetic coil 38 is wound around the provided cylindrical body 36 so as to generate a magnetic field opposite to the first electromagnet 3A. ing. Although the electromagnetic coils 32 of the first electromagnets 3A1 and 3A2 are connected in series, they may be connected in parallel. However, the winding direction is formed in the same direction. On the other hand, the third electromagnetic coil 38 of the second electromagnet 3B is preferably connected in series in the opposite direction to the electromagnetic coil 32 of the first electromagnet 3A. This is because currents need to be input simultaneously.

  Also in the example shown in FIG. 2, as in the case of FIG. 1, a plurality of terminals 38 a, 38 b, and 38 c are formed in the third electromagnetic coil 38, and the connection can be switched by the changeover switch 61. ing. Other configurations are the same as those in the example shown in FIG. 1 described above, and the same portions are denoted by the same reference numerals and description thereof is omitted.

  As shown in FIG. 3A (power supply circuit 6 is not shown), the vapor deposition apparatus according to one embodiment of the present invention has an electromagnet 3 placed on the touch plate 4 and the surface of one magnetic pole of the electromagnet 3. A substrate holder 29 provided so that the deposition substrate 2 can be held via the touch plate 4, a deposition mask 1 provided on the opposite side of the electromagnet 3 of the deposition substrate 2 held by the substrate holder 29, and a deposition mask. 1 and a vapor deposition source 5 for vaporizing or sublimating the vapor deposition material. The vapor deposition mask 1 has a metal layer made of a magnetic material (metal support layer 12: see FIG. 3B), and the electromagnet 3 is attached to the electromagnetic coils 32 and 35 so as to attract the metal support layer 12 of the vapor deposition mask 1. It is connected to a power supply circuit 6 (see FIGS. 1 and 2 and 3C) for applying a current. The vapor deposition mask 1 is placed on the mask holder 15, and the substrate holder 29 and the support frame 41 that holds the touch plate 4 are respectively lifted upward. Then, the deposition substrate 2 transported by a robot arm (not shown) is placed on the substrate holder 29 and the substrate holder 29 is lowered, so that the deposition substrate 2 comes into contact with the deposition mask 1. Further, by lowering the support frame 41, the touch plate 4 is overlapped with the deposition target substrate 2. On top of that, the electromagnet 3 is mounted on the touch plate 4 by operating an electromagnet support member (not shown). The touch plate 4 is provided to flatten the deposition target substrate 2 and to cool the deposition target substrate 2 and the deposition mask 1 by circulating cooling water (not shown). The touch plate 4 has a material and a thickness determined to make the in-plane distribution of the magnetic field uniform on the surface of the vapor deposition mask 1.

  In the electromagnet 3, as schematically shown in FIG. 3C, first and second electromagnetic coils 32 and 35 are wound around a core (magnetic core) 31 made of an iron core or the like. As described above, the second electromagnetic coil 35 is wound in the opposite direction to the electromagnetic coil 32 of the first electromagnet 3A. In FIG. 3A, for example, the size of the vapor deposition mask 1 is about 1.5 m × 1.8 m, so that the electromagnet having the magnetic core 31 whose section of the unit electromagnet shown in FIG. 3C is about 5 cm square. 3 shows a structure in which a plurality of (each electromagnet is referred to as a unit electromagnet) arranged in accordance with the size of the vapor deposition mask 1 (in FIG. 3A, the horizontal direction is reduced and the number of unit electromagnets is small. ) In the example shown in FIG. 3A, first and second electromagnetic coils 32 and 35 wound around each magnetic core 31 are connected in series, and a plurality of unit electromagnets are connected in series. That is, the unit electromagnet terminals 32b, 32c, and 32d are connected in series, and the terminals 32a and 32e at both ends are connected to a power supply circuit (not shown). However, the electromagnetic coils 32 of the respective unit electromagnets may be connected in parallel. Several units may be connected in series. A current may be applied independently to a part of the unit electromagnet. However, it is preferable that the current is applied simultaneously by a plurality of unit electromagnets.

  When a direct current flows through the electromagnetic coil 32 of the electromagnet 3, as shown in FIG. 3D, a magnetic field H is generated according to the right-handed screw law. When a magnetic material is placed in the magnetic field H, magnetism corresponding to the magnitude of the magnetic field H is induced in the magnetic material. As described above, the magnitude of the magnetic field H is determined by the product N · I of the number N of turns of the electromagnetic coil 32 and the magnitude I of the flowing current. Therefore, as the number N of turns of the electromagnetic coil 32 is increased and the current I is increased, a larger magnetomotive force N · I can be obtained. However, since electromagnetic induction occurs according to the rate of change of N · I, as described above, trouble occurs when this change is too large. Therefore, the above-described second electromagnet 3B (see FIG. 3C) is formed so as not to cause a sudden change in the magnetic field H.

  In the example shown in FIG. 3A, the periphery of the unit electromagnet is fixed with a resin 33 such as silicone rubber, silicone resin, or epoxy resin. Although this resin 33 is not necessarily required, the unit electromagnet can be fixed and the electromagnet 3 can be easily handled. However, in the present embodiment, since the electromagnet 3 is used in a vacuum state, the electromagnet 3 can be cooled by heat radiation through the surroundings instead of solidifying the unit electromagnet with the resin 33. May be. At this time, it is preferable that the surface of the electromagnet 3 is a treated surface that has been subjected to blackening treatment such as alumite treatment. Further, the surface of the electromagnet 3 may be a roughened surface that is a rough surface with an arithmetic average roughness Ra of 10 μm or more, for example. That is, it is preferable that the surface is roughened so that the surface roughness is Ra 10 μm or more. A surface roughness of Ra 10 μm means that the surface area becomes 2.18 times if the convex portion formed by roughening is an ideal hemisphere. As a result, the heat dissipation effect is more than doubled. The cooling device has a broad meaning including the electromagnet 3 having a surface on which the treated surface of the electromagnet 3 is formed in addition to the device capable of performing such heat radiation or water cooling as described above. When a large amount of current is continuously passed, the electromagnet 3 may generate heat. In such a case, it is preferable to cool the electromagnet 3 by water cooling. For example, it is conceivable that a water-cooled tube is embedded in the above-described resin 33 to flow cooling water.

  As shown in FIG. 3A, a substrate holder 29 and a mask holder 15 are provided in the vapor deposition apparatus. The substrate holder 29 is connected to a driving device (not shown) so that the peripheral portion of the deposition target substrate 2 is held by a plurality of hook-shaped arms and can be moved up and down. The deposition substrate 2 carried into the chamber by the robot arm is received by the hook-shaped arm, and the substrate holder 29 is lowered until the deposition substrate 2 comes close to the deposition mask 1. An imaging device (not shown) is also provided so that alignment can be performed. The touch plate 4 is supported by a support frame 41 and is connected via a support frame 41 to a driving device that lowers the touch plate 4 until it comes into contact with the deposition target substrate 2. By lowering the touch plate 4, the deposition target substrate 2 is flattened. The vapor deposition apparatus captures the vapor deposition substrate 2 while imaging the alignment marks formed on the vapor deposition mask 1 and the vapor deposition substrate 2 when aligning the vapor deposition mask 1 and the vapor deposition substrate 2 of this embodiment. A fine movement device that moves relative to the vapor deposition mask 1 is also provided. The alignment is performed in a state where energization of the electromagnet 3 is stopped so that the vapor deposition mask 1 is not unnecessarily attracted by the electromagnet 3. As described above, according to the present embodiment, by performing both of the first and second electromagnets 3A and 3B during the alignment, the alignment is performed by bringing them close to each other under a weak magnetic field. Can be done. Although not shown, the vapor deposition apparatus is also provided with a device in which the entire apparatus shown in FIG. 3A is placed in a chamber and the inside is evacuated.

  As shown in FIG. 3B, the vapor deposition mask 1 includes a resin film 11, a metal support layer 12, and a frame (frame body) 14 formed around the resin film 11, and the vapor deposition mask 1 is shown in FIG. 3A. Thus, the frame 14 is placed on the mask holder 15. A magnetic material is used for the metal support layer 12. As a result, an attraction force works between the electromagnet 3 and the magnetic core 31 and is attracted with the deposition substrate 2 interposed therebetween. The metal support layer 12 may be made of a ferromagnetic material. In this case, the metal support layer 12 is magnetized (a state in which strong magnetization remains even when the external magnetic field is removed) by the strong magnetic field of the electromagnet 3. When such a ferromagnetic material is used, when the electromagnet 3 and the vapor deposition mask 1 are separated, it is easier to separate the electromagnet 3 by applying a reverse current. Even when a strong magnetic field for such magnetization is generated, the present embodiment does not cause trouble due to electromagnetic induction. Further, when the electromagnet 3 and the vapor deposition mask 1 are separated, both the first and second electromagnets 3A and 3B can be operated.

  As the metal support layer 12, for example, Fe, Co, Ni, Mn, or an alloy thereof can be used. Among them, invar (Fe and Ni alloy) is particularly preferable because of a small difference in linear expansion coefficient from the deposition target substrate 2 and almost no expansion due to heat. The metal support layer 12 has a thickness of about 5 μm to 30 μm.

  In FIG. 3B, the opening 11a of the resin film 11 and the opening 12a of the metal support layer 12 are tapered so as to taper toward the deposition target substrate 2 (see FIG. 3A). The reason is explained below. As the vapor deposition source 5, various vapor deposition sources 5 such as a dot shape, a line shape, and a planar shape can be used. For example, a line-type deposition source 5 (extending in a direction perpendicular to the paper surface of FIG. 3A) in which crucibles are arranged in a line is scanned from the left end to the right end of the paper surface, for example, so that the entire surface of the deposition substrate 2 Vapor deposition is performed. As described above, the vapor deposition source 5 radiates the vapor deposition material so that the cross-sectional shape of the radiation beam of the vapor deposition material determined by the shape of the crucible has a cross-sectional fan shape extending at a constant angle θ. The opening of the metal support layer 12 and the resin film 11 is such that the vapor deposition particles in the vicinity of the side surface of the fan-shaped cross-sectional shape reach a predetermined place on the deposition target substrate 2 without being blocked by the metal support layer 12 or the resin film 11. 12a and opening 11a are formed in a taper shape. As long as the opening 12a of the metal support layer 12 is formed large, it does not have to be tapered.

(Vapor deposition method)
Next, a deposition method according to an embodiment of the present invention will be described. In the vapor deposition method of the embodiment of the present invention, as shown in FIG. 3A described above, the electromagnet 3, the deposition target substrate 2, and the vapor deposition mask 1 having a magnetic material are overlaid, and the power supply circuit 6 (FIG. 1-2), the substrate 2 and the deposition mask 1 are adsorbed by energization of the electromagnet 3 and the scattering of the deposition material 51 from the deposition source 5 disposed away from the deposition mask 1. A step of depositing a vapor deposition material 51 on the vapor deposition substrate 2. The electromagnet 3 includes a first electromagnet 3A that generates a magnetic field in a first direction, and a second electromagnet 3B that generates a magnetic field in a direction opposite to the first direction. This is done by turning off the second electromagnet 3B after simultaneous energization of the electromagnets 3A and 3B. Before the adsorption by the electromagnet 3, the deposition mask 1 and the deposition target substrate 2 may be aligned.

  As described above, the deposition target substrate 2 is overlaid on the deposition mask 1. The alignment between the deposition substrate 2 and the deposition mask 1 is performed as follows. This is performed by moving the deposition target substrate 2 relative to the deposition mask 1 while observing alignment marks formed on the deposition target substrate 2 and the deposition mask 1 with an imaging device. At this time, as described above, if both the first and second electromagnets 3A and 3B are operated, the deposition substrate 2 and the deposition mask 1 can be brought close to each other with a weak magnetic field. However, the alignment may be performed without generating any magnetic field. By this method, the opening 11a of the vapor deposition mask 1 and the vapor deposition location (for example, the pattern of the 1st electrode 22 of an apparatus substrate in the case of the organic EL display device mentioned later) can be made to correspond. After the alignment, the second electromagnet 3B is turned off, or the first and second electromagnets 3A and 3B are operated, and then the second electromagnet 3B is turned off. When the magnetic flux is stabilized, the magnetic flux is maintained, there is almost no generation of electromagnetic induction, and a stable magnetic field can be obtained. As a result, a strong attractive force acts between the electromagnet 3 and the vapor deposition mask 1 so that the vapor deposition target substrate 2 and the vapor deposition mask 1 are brought close to each other.

  After that, as shown in FIG. 3A, the vapor deposition material 51 is deposited on the deposition target substrate 2 by scattering (vaporization or sublimation) of the vapor deposition material 51 from the vapor deposition source 5 disposed away from the vapor deposition mask 1. Specifically, as described above, a line source such as a crucible arranged in a line is used, but the present invention is not limited to this. For example, when an organic EL display device is manufactured, a plurality of types of vapor deposition masks 1 having openings 11a formed in some pixels are prepared, and the vapor deposition mask 1 is replaced to form an organic layer by a plurality of vapor deposition operations. .

  According to this vapor deposition method, the magnetic field (magnetic flux) generated by the electromagnet 3 is small in the initial stage of current application due to the cancellation of the first electromagnet 3A and the second electromagnet 3B. Electromotive force due to induction is suppressed. However, when the second electromagnet 3B is turned off, the magnetic field becomes the original magnetic field, and the deposition substrate 2 and the deposition mask 1 can be sufficiently approached by the strong adsorption force. The turning off of the second electromagnet 3B may not be performed at a time but may be performed step by step. As a result, the overcurrent flowing through the deposition substrate 2 due to electromagnetic induction is suppressed, and the influence on the elements and organic materials formed on the deposition substrate 2 can be suppressed.

  In the present embodiment, even when the electromagnet 3 is turned off in order to remove the deposition target substrate 2 after the completion of vapor deposition, it can be performed by a method opposite to that for supplying current. That is, it is preferable that the electromagnet 3 is turned off after the second electromagnet 3B is operated. When the first electromagnet 3A is turned off, the current suddenly changes from a predetermined value to 0. Therefore, electromagnetic induction in the direction opposite to that at the time of current application occurs, but the electromagnetic induction can be controlled to be small. .

(Method for manufacturing organic EL display device)
Next, a method for manufacturing an organic EL display device using the vapor deposition method of the above embodiment will be described. Since a manufacturing method other than the vapor deposition method can be performed by a known method, a method for laminating an organic layer by the vapor deposition method of the present invention will be mainly described with reference to FIGS.

  In the method of manufacturing an organic EL display device according to an embodiment of the present invention, a TFT, a planarizing film, and a first electrode (for example, an anode) 22 (not shown) are formed on a support substrate 21, and the vapor deposition mask 1 is positioned on one surface. When the vapor deposition material 51 is vapor-deposited, the organic layer laminated film 25 is formed using the above-described vapor deposition method. A second electrode 26 (see FIG. 6; cathode) is formed on the laminated film 25.

For example, the support substrate 21 such as a glass plate is not completely illustrated, but a drive element such as a TFT is formed for each RGB sub-pixel of each pixel, and the first electrode 22 connected to the drive element is flat. On the conversion film, it is formed by a combination of a metal film such as Ag or APC and an ITO film. As shown in FIGS. 5 to 6, an insulating bank 23 made of SiO _2, acrylic resin, polyimide resin, or the like is formed between the sub-pixels. On the insulating bank 23 of the support substrate 21, the above-described vapor deposition mask 1 is aligned and fixed. As shown in FIG. 3A described above, this fixing is performed, for example, by using an electromagnet 3 provided on the opposite side of the deposition surface of the support substrate 21 via the touch plate 4 and attracting it. As described above, since the magnetic material is used for the metal support layer 12 (see FIG. 3B) of the vapor deposition mask 1, when the magnetic field is applied by the electromagnet 3, the metal support layer 12 of the vapor deposition mask 1 is magnetized to become a magnetic core. A suction force is generated between the unit 31 and the unit 31. Even when the electromagnet 3 does not have the magnetic core 31, it is attracted by the magnetic field generated by the current flowing through the electromagnetic coil 32. At this time, as described above, when the current is turned on, the first and second electromagnets 3A and 3B are operated at the same time, so that a rapid magnetic flux change does not occur. Therefore, the influence of electromotive force due to electromagnetic induction is suppressed. The opening 11a of the vapor deposition mask 1 is formed smaller than the interval between the surfaces of the insulating bank 23. An organic material is prevented from being deposited on the side wall of the insulating bank 23 as much as possible to prevent a decrease in light emission efficiency of the organic EL display device.

  In this state, as shown in FIG. 5, the vapor deposition material 51 is scattered from the vapor deposition source (crucible) 5 in the vapor deposition apparatus, and the vapor deposition material is formed on the support substrate 21 only in the portion where the opening 11a of the vapor deposition mask 1 is formed. 51 is vapor-deposited, and an organic layer laminated film 25 is formed on the first electrode 22 of the desired sub-pixel. As described above, since the opening 11 a of the vapor deposition mask 1 is formed smaller than the interval between the surfaces of the insulating bank 23, the vapor deposition material 51 is hardly deposited on the side wall of the insulating bank 23. As a result, as shown in FIGS. 5 to 6, the organic layer laminated film 25 is deposited almost only on the first electrode 22. This vapor deposition process may be performed for each sub-pixel by sequentially replacing the vapor deposition mask 1. The vapor deposition mask 1 in which the same material is vapor-deposited simultaneously on a plurality of subpixels may be used. When the deposition mask 1 is replaced, a power supply circuit is used to remove a magnetic field applied to the metal support layer 12 (see FIG. 3B) of the deposition mask 1 by an electromagnet 3 (see FIG. 3A) not shown in FIG. 6 (see FIGS. 1-2) is turned off. Also in this case, it is preferable that the power supply circuit 6 is turned off after the second electromagnet 3B is operated so that an element such as a TFT formed on the support substrate 21 can suppress the influence of electromagnetic induction.

In FIGS. 5 to 6, the organic layer laminated film 25 is simply shown as one layer, but the organic layer laminated film 25 may be formed of a plurality of laminated films 25 made of different materials. For example, as a layer in contact with the anode 22, a hole injection layer made of a material with good ionization energy consistency that improves hole injection may be provided. On this hole injection layer, a hole transport layer capable of improving the stable transport of holes and confining electrons (energy barrier) in the light emitting layer is formed of, for example, an amine material. Further, a light emitting layer selected on the basis of the light emission wavelength is formed by doping Alq ₃ with red or green organic fluorescent material for red, green, for example. As the blue material, a DSA organic material is used. On the light emitting layer, an electron transport layer that further improves the electron injection property and stably transports electrons is formed of Alq ₃ or the like. By laminating each of these layers by several tens of nanometers, an organic layer laminated film 25 is formed. An electron injection layer that improves electron injection properties such as LiF and Liq may be provided between the organic layer and the metal electrode. In the present embodiment, these are also referred to as a laminated film 25 of organic layers. Such a laminated film 25 may be affected by electromagnetic induction, but in this embodiment, as described above, a magnetic field opposite to that of the first electromagnet 3A is generated when current is supplied or cut. Since the second electromagnet 3B to be operated is operated, a sudden change in the magnetic field does not occur. As a result, the influence of electromagnetic induction is suppressed.

  In the organic layer laminated film 25, the light emitting layer is deposited with an organic layer of a material corresponding to each color of RGB. In addition, the hole transport layer, the electron transport layer, and the like are preferably deposited separately using a material suitable for the light emitting layer if the light emitting performance is important. However, in consideration of the material cost, there are cases where two or three colors of RGB are laminated with the same material. In the case where materials common to subpixels of two or more colors are stacked, the vapor deposition mask 1 in which openings are formed in the common subpixels is formed. In the case where the vapor deposition layers are different in individual sub-pixels, for example, each organic layer can be vapor-deposited continuously using one vapor deposition mask 1 in the R sub-pixels. In addition, when a common organic layer is deposited in RGB, the organic layer of each sub-pixel is vapor-deposited to the lower side of the common layer, and vapor deposition in which openings are formed in RGB at the common organic layer. Using the mask 1, the organic layers of all the pixels are deposited at once. In the case of mass production, a number of chambers of the vapor deposition apparatus are arranged, and different vapor deposition masks 1 are attached to the respective chambers. A support substrate 21 (deposition target substrate 2) moves continuously through each vapor deposition apparatus. Alternatively, vapor deposition may be performed.

When the formation of the laminated film 25 of all organic layers including the electron injection layer such as the LiF layer is completed, the power supply circuit 6 of the electromagnet 3 is turned off and the electromagnet 3 is separated from the vapor deposition mask 1 as described above. Thereafter, a second electrode (for example, a cathode) 26 is formed on the entire surface. The example shown in FIG. 6 is a top emission type and emits light from the surface opposite to the support substrate 21 in the figure. Therefore, the second electrode 26 is made of a translucent material, for example, a thin film of Mg—Ag. It is formed by a eutectic film. In addition, Al or the like can be used. In the case of a bottom emission type in which light is emitted from the support substrate 21 side, ITO, In ₃ O ₄ or the like is used for the first electrode 22, and a metal having a small work function, for example, Mg, K, Li, Al, etc. can be used. A protective film 27 made of, for example, Si ₃ N ₄ is formed on the surface of the second electrode 26. The entirety is sealed by a sealing layer made of glass, resin film, or the like (not shown), and the organic layer laminated film 25 is configured not to absorb moisture. Further, the organic layer can be made as common as possible, and a color filter can be provided on the surface side.

(Summary)
(1) The vapor deposition apparatus according to the first embodiment of the present invention is provided at a position facing an electromagnet, one magnetic pole of the electromagnet, and holds the substrate to be deposited, and is held by the substrate holder. An evaporation mask having a magnetic material provided at a position opposite to the surface opposite to the electromagnet of the evaporation target substrate, an evaporation source provided to oppose the evaporation mask and vaporizing or sublimating an evaporation material, and the electromagnet A first power generation circuit that generates a magnetic field in a first direction, and a second power generation circuit that generates a magnetic field in a direction opposite to the first direction. And an electromagnet.

  According to the vapor deposition apparatus of one embodiment of the present invention, the vapor deposition mask is attracted by an electromagnet, and therefore, the alignment between the vapor deposition substrate and the vapor deposition mask can be easily performed without applying a magnetic field or with a weak magnetic field. It can be carried out. Further, by applying a magnetic field, the deposition target substrate and the deposition mask sandwiched therebetween can be sufficiently brought close to each other. In addition, in the present embodiment, the electromagnet includes a first electromagnet that generates a magnetic field in the first direction, and a second electromagnet that generates a magnetic field in the second direction opposite to the first direction. . Therefore, the magnetic field can be weakened by the operation of the second electromagnet when the current is supplied. By doing so, even when a current is supplied to the electromagnet, it is possible to suppress an element such as a TFT formed on the evaporation target substrate from being affected by electromagnetic induction generated by the current supply.

  (2) The power supply circuit has a changeover switch for turning off the energization of the second electromagnet after the energization of the first and second electromagnets simultaneously, thereby avoiding the influence of electromagnetic induction when the energization is started. However, a desired magnetic field can be obtained during normal operation.

  (3) A first electromagnetic coil corresponding to the first electromagnet and a second electromagnetic coil corresponding to the second electromagnet are connected in series, and the second electromagnetic coil is the first electromagnetic coil. The number of turns may be smaller than that of the coil and may be wound in the direction opposite to that of the first electromagnetic coil. By connecting two electromagnetic coils in series, it is possible to simultaneously apply current to the two electromagnets. Further, part of the magnetic field generated by the first electromagnetic coil is canceled by the second electromagnetic coil.

  (4) In addition to the terminals at both ends, the second electromagnetic coil has a third terminal in the middle of the second electromagnetic coil, and the changeover switch is stepwise by switching the terminals of the second electromagnetic coil. The energization of the second electromagnet may be turned off. The influence of electromagnetic induction that can occur by turning off the second electromagnet can be avoided.

  (5) The first electromagnet is formed by arranging a plurality of unit electromagnets, and the second electromagnet is formed by a third electromagnetic coil wound so as to surround the plurality of unit electromagnets. Also good. It can be selected depending on the space of the electromagnet.

  (6) In addition to the terminals at both ends, the third electromagnetic coil has a third terminal in the middle of the third electromagnetic coil, and the changeover switch is stepwise by switching the terminals of the third electromagnetic coil. The energization of the second electromagnet can be turned off. As described above, the second electromagnet can be turned off step by step.

  (7) Further, in the vapor deposition method according to the second embodiment of the present invention, the electromagnet, the deposition target substrate, and the vapor deposition mask having a magnetic material are superposed, and the electromagnet is energized from a power supply circuit. Adsorbing the vapor deposition substrate and the vapor deposition mask, and depositing the vapor deposition material on the vapor deposition substrate by scattering of the vapor deposition material from a vapor deposition source disposed away from the vapor deposition mask, The electromagnet includes a first electromagnet that generates a magnetic field in a first direction and a second electromagnet that generates a magnetic field in a direction opposite to the first direction, and the first and second electromagnets are simultaneously used. Turning off the second electromagnet after the energization.

  According to the vapor deposition method of the second embodiment of the present invention, when the current is supplied to the electromagnet, the first electromagnet and the second electromagnet operate simultaneously, so the magnetic field becomes weak and the influence of electromagnetic induction is suppressed. Is done. On the other hand, since the second electromagnet is turned off after the current is supplied, the magnetic field generated by the first electromagnet is provided as it is, and the necessary attractive force is obtained. As a result, deterioration of the characteristics of the element and the organic layer can be suppressed while the adsorption of the deposition substrate and the deposition mask is sufficiently performed.

  (8) When turning off the second electromagnet, by turning it off in stages, the occurrence of reverse electromagnetic induction when turning off the second electromagnet can be suppressed.

  (9) After the vapor deposition of the vapor deposition material is completed, the second electromagnet is operated, and then the current to the electromagnet is turned off, so that the generation of electromagnetic induction when the current is turned off can be suppressed. .

  (10) Furthermore, in the method for manufacturing an organic EL display device according to the third embodiment of the present invention, at least a TFT and a first electrode are formed on a support substrate, and the above (7) to (9) are formed on the support substrate. Forming a laminated film of an organic layer by vapor-depositing an organic material using any one of the vapor deposition methods, and forming a second electrode on the laminated film.

  According to the manufacturing method of the organic EL display device of the third embodiment of the present invention, when the organic EL display device is manufactured, the characteristics of the elements and the organic layer formed on the support substrate are not deteriorated and are delicate. Display screen with a simple pattern.

DESCRIPTION OF SYMBOLS 1 Deposition mask 2 Deposited substrate 3 Electromagnet 3A 1st electromagnet 3B 2nd electromagnet 4 Touch plate 5 Deposition source 6 Power supply circuit 11 Resin film 11a Opening 12 Metal support layer 12a Opening 14 Frame 15 Mask holder 21 Support substrate 22 1st Electrode 23 Insulation bank 25 Laminated film 26 Second electrode 27 Protective film 29 Substrate holder 31 Magnetic core (core)
32 Electromagnetic coil (first electromagnetic coil)
33 resin 35 second electromagnetic coil 35a, 35b, 35c terminal 36 cylinder 38 third electromagnetic coil 38a, 38b, 38c terminal 41 support frame 51 vapor deposition material 60 main switch 61 changeover switch

Claims (11)

A first electromagnet for generating a magnetic field directed in a first direction;
A second electromagnet for generating a second magnetic field opposite to the first orientation;
A holder on which a member having a magnetic body is to be placed, the member being attracted to the electromagnet by energization of the electromagnet after being placed on the holder. Vapor deposition equipment.   A first electromagnetic coil corresponding to the first electromagnet and a second electromagnetic coil corresponding to the second electromagnet are continuously formed, and the first electromagnetic coil and the second electromagnetic coil are formed. The vapor deposition apparatus according to claim 1, wherein the electromagnetic coil is wound in a reverse direction.   The vapor deposition apparatus according to claim 1, further comprising a switch unit that turns off the energization of the second electromagnetic coil after energization of the first and second electromagnetic coils.   In addition to the terminals at both ends, the second electromagnetic coil has at least one third terminal in the middle of the second electromagnetic coil, and the switch means stepwise by passing through the third terminal. The vapor deposition apparatus of Claim 3 which turns off electricity supply of a 2nd electromagnet.   The first electromagnet is formed by arranging a plurality of unit electromagnets, and the second electromagnet is formed by a third electromagnetic coil wound around the plurality of unit electromagnets. 2. The vapor deposition apparatus according to 1.   In addition to switching means for turning off the third electromagnetic coil after the first and second electromagnets are energized, the third electromagnetic coil is in the middle of the third electromagnetic coil in addition to the terminals at both ends. The vapor deposition apparatus according to claim 5, further comprising a third terminal, wherein the switch means turns off the energization of the second electromagnet in a stepwise manner through the third terminal.   The vapor deposition apparatus of any one of Claims 1-6 further provided with the cooling device which cools the said electromagnet.   The said member is a vapor deposition apparatus of any one of Claims 1-7 which is a to-be-deposited board | substrate with which an organic material is vapor-deposited. A second holder on which a deposition mask having a magnetic material is to be placed;
The vapor deposition apparatus according to claim 8, wherein the vapor deposition mask is in contact with the vapor deposition substrate adsorbed to the electromagnet by energization of the electromagnet after being placed on the second holder.   The vapor deposition method using the vapor deposition apparatus of Claim 8 or 9. Forming a TFT and a first electrode on a support substrate;
The support substrate and the deposition mask are arranged in the deposition apparatus according to claim 9,
Energizing the electromagnet to fix the support substrate and the vapor deposition mask to the electromagnet;
Laminating an organic layer on the support substrate,
The manufacturing method of an organic electroluminescence display including forming a 2nd electrode on the laminated | stacked said organic layer.

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