electromagnetic device

Abstract

To reduce heat generation in an electromagnet device.SOLUTION: An electromagnet device 100 comprises: a yoke 112; a coil 114 wound around the yoke 112; a housing (an upper housing 150, a lower housing 160) which houses the yoke 112 and the coil 114, and which has an attraction surface 105 that attracts an object by magnetic force; and a heat insulation layer 120 which is disposed between a tip end of the yoke 112 and an inner surface on the attraction surface 105 side of the housing. The heat insulation layer 120 is an air layer or a vacuum layer, or a layer through which a coolant circulates.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an electromagnetic device. [Background technology]

[0002] An electromagnet device generates a magnetic force by passing a current through a coil. The current flowing through the coil causes the coil to generate heat. Furthermore, in a manufacturing apparatus for organic electroluminescent devices, such as that shown in Patent Document 1, a permanent magnet is typically used to tightly attach a metal mask to a substrate. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-062125 Summary of the Invention [Problem to be solved by the invention]

[0004] It is desirable to reduce the heat generated by the electromagnetic device, for example, because the heat generated by the electromagnetic device may cause deformation of the metal mask. [Means for solving the problem]

[0005] In order to solve the above-mentioned problems, an electromagnetic device is disclosed that includes a yoke, a coil wound around the yoke, a housing that houses the yoke and the coil and has an attraction surface to which an object is attracted by magnetic force, and an insulating layer that is arranged between the tip of the yoke and the inner surface of the housing on the attraction surface side. [Brief explanation of the drawings]

[0006] [Figure 1] 1 is a partial cross-sectional view showing a configuration of an electromagnet device according to an embodiment. [Figure 2A]FIG. 2 is a cross-sectional view showing the configuration of a yoke in an electromagnet device according to one embodiment. [Figure 2B] FIG. 2 is a cross-sectional view showing the configuration of a yoke in an electromagnet device according to one embodiment. [Figure 3] FIG. 2 is a top view showing the overall configuration of a lower housing in the electromagnetic device according to the embodiment. [Figure 4] 1 is a diagram illustrating an apparatus for manufacturing an organic electroluminescent device to which an electromagnet device according to an embodiment can be applied; [Figure 5] FIG. 1 is a configuration diagram of an electromagnet control system according to an embodiment. [Figure 6] FIG. 10 is a diagram showing another example in which a plurality of electromagnet units are divided into a plurality of areas. [Figure 7] FIG. 10 is a diagram showing yet another example in which a plurality of electromagnet units are divided into a plurality of areas. [Figure 8] FIG. 10 is a diagram showing an example of the temporal relationship of currents flowing through coils of electromagnet units in each area. DETAILED DESCRIPTION OF THE INVENTION

[0007] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the accompanying drawings, identical or similar elements are designated by identical or similar reference numerals, and duplicate descriptions of identical or similar elements may be omitted in the description of each embodiment. Furthermore, features shown in each embodiment may also be applied to other embodiments as long as they are not mutually inconsistent.

[0008] 1 is a partial cross-sectional view showing the configuration of an electromagnet device 100 according to one embodiment of the present invention. The electromagnet device 100 includes a plurality of electromagnet units 110, a cooling plate 140, an upper housing 15, and a 0 and a lower housing 160.

[0009] A plurality of beams 162 are provided on the inner surface of the lower housing 160 to increase the rigidity of the lower housing 160. By providing the beams 162, it is possible to reduce the thickness t of the lower housing 160 on the attraction surface 105 side of the electromagnet device 100. Furthermore, because the thickness t of the lower housing 160 is thin, the magnetic field generated from the electromagnet unit 110 can be efficiently transmitted to the outside of the electromagnet device 100.

[0010] Each of the multiple electromagnet units 110 is disposed in a separate small space inside the lower housing 160, separated by beams 162 of the lower housing 160. Each electromagnet unit 110 includes a yoke 112 and a coil 114 wound around the yoke 112 and molded with a resin material 116. The resin molding material 116 preferably has high thermal conductivity, high heat resistance, and a low linear expansion coefficient (e.g., epoxy). A magnetic pole MP1 (one of the north and south poles) and a magnetic pole MP2 (the other of the north and south poles) are formed at the tip of the yoke 112 by a current flowing through the coil 114. Each electromagnet unit 110 is disposed so that the tip of the yoke 112 faces the bottom of the lower housing 160. The magnetic poles MP1 and MP2 of each electromagnet unit 110 can attract an object located at the bottom of the lower housing 160, i.e., below the attraction surface 105 of the electromagnet device 100.

[0011] The upper part of the electromagnet unit 110 is in thermal contact with the cooling plate 140 via a heat transfer sheet 145 having a relatively high thermal conductivity. The cooling plate 140 has water-cooling piping 142 therein and is capable of cooling the electromagnet unit 110. This allows heat generated in the coil 114 when the electromagnet unit 110 is driven to be dissipated to the outside of the electromagnet device 100 through the cooling plate 140 and the water-cooling piping 142.

[0012] The electromagnet device 100 of this embodiment further includes a heat insulating layer 120 between the tip portion (where the magnetic poles MP1 and MP2 are formed) of the yoke 112 of the electromagnet unit 110 and the bottom of the lower housing 160. The presence of the heat insulating layer 120 makes it difficult for heat generated in the coil 114 when the electromagnet unit 110 is driven to be transferred to the attraction surface 105 of the electromagnet device 100. This makes it possible to avoid problems caused by heating of the attracted object via the attraction surface 105. For example, when the electromagnet device 100 of this embodiment is used to attract a metal mask to a substrate in a manufacturing process for an organic electroluminescent device, it is possible to prevent deformation of the metal mask due to heat and poor adhesion to the substrate.

[0013] The heat insulating layer 120 may be configured as, for example, an air layer or a vacuum layer, or alternatively, the heat insulating layer 120 may be configured so that a gaseous or liquid coolant flows through the gap between the tip portion of the yoke 112 of the electromagnet unit 110 and the bottom of the lower housing 160.

[0014] In a configuration in which a coolant serving as the insulating layer 120 flows through the gap between the tip of the yoke 112 and the bottom of the lower housing 160, the temperature, flow rate, or flow velocity of the coolant may be dynamically changed when the electromagnet unit 110 is driven. In one aspect, the electromagnetic device 100 further includes an ammeter (not shown) that measures the current flowing through the coil 114. The heat generation amount of the coil 114 can be calculated or estimated from the current value measured by the ammeter. The temperature, flow rate, or flow velocity of the coolant is adjusted according to the calculated heat generation amount of the coil 114 or directly according to the magnitude of the current flowing through the coil 114 measured by the ammeter. For example, the heat generation amount of the coil 114 increases as the temperature of the coolant is lowered or the flow rate or flow velocity of the coolant is increased, thereby further improving the insulating effect from the electromagnet unit 110 to the attraction surface 105 of the electromagnetic device 100.

[0015] In another embodiment, the electromagnetic device 100 measures the temperature of each part of the electromagnetic device 100. The electromagnetic device 100 further includes a temperature sensor (not shown) for measuring the temperature of the yoke 112, the bottom (attraction surface 105) of the lower housing 160, or the refrigerant serving as the thermal insulating layer 120. The temperature sensor is disposed at a position capable of measuring the temperature of the yoke 112, the bottom (attraction surface 105) of the lower housing 160, or the refrigerant serving as the thermal insulating layer 120. Alternatively, the temperature sensor may be disposed so as to measure the temperature of an object attracted to the suction surface 105 of the electromagnetic device 100. The temperature, flow rate, or flow velocity of the refrigerant serving as the thermal insulating layer 120 circulating in the gap between the tip portion of the yoke 112 and the bottom of the lower housing 160 is adjusted according to the temperature of each part of the electromagnetic device 100 measured by the temperature sensor or the temperature of the object to be attracted to the suction surface 105. For example, when a temperature rise at the bottom (attraction surface 105) of the lower housing 160 is detected, the temperature, flow rate, or flow velocity of the refrigerant is lowered or the flow rate or flow velocity of the refrigerant is increased, thereby further improving the thermal insulating effect from the electromagnet unit 110 to the suction surface 105 of the electromagnetic device 100.

[0016] Furthermore, the cooling capacity of the cooling plate 140 may be dynamically changed in accordance with the amount of heat generated by the coil 114 or the temperature of each part of the electromagnetic device 100 or the object to be attracted, as described above.

[0017] 2A and 2B are cross-sectional views showing the configuration of a yoke 112 in an electromagnet device 100 according to one embodiment of the present invention. In the electromagnet device 100 of this embodiment, the yoke 112 of each electromagnet unit 110 has a tip portion 112a formed to be wider than a portion 112b around which the coil 114 is wound. The cross-sectional area through which the magnetic flux penetrates the yoke 112 at the tip portion 112a of the yoke 112 is larger than the cross-sectional area through which the magnetic flux penetrates the yoke 112 at the coil winding portion 112b of the yoke 112. By forming the tip portion 112a of the yoke 112 to be wider, the magnetic field generated by the electromagnet unit 110 can be increased.

[0018] Because the yoke has a high relative permeability and a low magnetic path resistance, by increasing the cross-sectional area of ​​tip portion 112a of yoke 112, electromagnet unit 110 can generate a high magnetic flux density over a wide range and can attract a wide range with a large force. On the other hand, the larger the cross-sectional area of ​​coil 114 wound around yoke 112, the more the amount of heat generated by coil 114 can be reduced. To ensure a large coil space, it is preferable to make the cross-sectional area of ​​yoke 112 at coil winding portion 112b small enough so that the magnetic flux density does not saturate.

[0019] FIG. 3 is a top view showing the overall configuration of the lower housing 160 in the electromagnet device 100 according to one embodiment of the present invention. As shown in FIG. 3, the lower housing 160 has a plurality of sectors 164 separated by beams 162. The lower housing 160 shown in FIG. 3 has a total of 64 sectors 164 arranged in four columns and sixteen columns. Note that the number of sectors 164 arranged vertically and horizontally is not limited to this and may be any number. As described above, the electromagnet device 100 is configured by disposing an electromagnet unit 110 (not shown in FIG. 3) in each of these sectors 164.

[0020] FIG. 4 shows an organic electroluminescent device manufacturing apparatus 500 to which the electromagnet device 100 according to one embodiment of the present invention can be applied. The organic electroluminescent device manufacturing apparatus 500 is, for example, a vapor deposition apparatus. As shown in the figure, a substrate 502 to be processed (e.g., a glass substrate) is placed on the attraction surface 105 of the electromagnet device 100, and a metal mask 504 is placed through the substrate 502. The metal mask 504 is attracted to the surface of the substrate 502 by the magnetic force generated by the electromagnet device 100. A vapor deposition source (e.g., a metal or organic material) released from a vapor deposition source 506 into a chamber 508 is deposited on the substrate 502 through the metal mask 504, thereby carrying out the organic electroluminescent device manufacturing process.

[0021] 5 is a configuration diagram of an electromagnet control system 200 according to one embodiment of the present invention. The electromagnet control system 200 includes the electromagnet device 100 described above with reference to FIGS. 1 to 3, and a controller 250 capable of individually driving each electromagnet unit 110 (not shown) of the electromagnet device 100.

[0022] The controller 250 drives the multiple electromagnet units 110 for each of the multiple areas. In the example of Fig. 5, the multiple electromagnet units 110 are divided into a total of eight areas, namely, a first area 201, a second area 202, a third area 203, a fourth area 204, a fifth area 205, a sixth area 206, a seventh area 207, and an eighth area 208, from left to right in the figure. The number of electromagnet units 110 included in each of the areas 201 to 208 may be any number, and therefore the electromagnet units 110 are not explicitly shown in Fig. 5. The number of divided areas is not limited to eight and may be any number.

[0023] For example, the controller 250 first turns on the electromagnet units 110 in the fourth area 204 and the fifth area 205, then turns on the electromagnet units 110 in the third area 203 and the sixth area 206, then turns on the electromagnet units 110 in the second area 202 and the seventh area 207, and finally turns on the electromagnet units 110 in the first area 201 and the eighth area 208. By turning on the electromagnet units 110 (passing current through the coils 114) in this manner, from the area located at the center of the electromagnet device 100 to the area located at the periphery, a thin object to be attracted, such as the metal mask 504 described above with reference to FIG. 4, can be attracted to the attraction surface 105 of the electromagnet device 100 or the surface of the substrate 502 without causing bending. This ensures good adhesion between the thin object to be attracted and the electromagnet device 100 or the substrate 502.

[0024] Furthermore, for example, the controller 250 may turn on the electromagnet units 110 in the order of the first area 201, the second area 202, the third area 203, the fourth area 204, the fifth area 205, the sixth area 206, the seventh area 207, and the eighth area 208. By turning on the electromagnet units 110 in this manner in order for each area from the area located at one end of the electromagnet device 100 to the area located at the other end, a thin object to be attracted can be attracted to the electromagnet device 100 or the substrate 502 without bending, as in the above case, and good adhesion can be ensured.

[0025] The method of dividing the electromagnet units 110 into the areas is not limited to that shown in Fig. 5. As another example, as shown in Fig. 6, the electromagnet units 110 may be divided into a total of eight areas, namely, a first area 211, a second area 212, a third area 213, a fourth area 214, a fifth area 215, a sixth area 216, a seventh area 217, and an eighth area 218, in that order from top to bottom in the figure. In the example of Fig. 6, the controller 250, for example, first turns on the electromagnet units 110 in the fourth area 214 and the fifth area 215, then turns on the electromagnet units 110 in the third area 213 and the sixth area 216, then turns on the electromagnet units 110 in the second area 212 and the seventh area 217, and finally turns on the electromagnet units 110 in the first area 211 and the eighth area 218. The controller 250 may also turn on the electromagnet units 110 in the order of the first area 211, the second area 212, the third area 213, the fourth area 214, the fifth area 215, the sixth area 216, the seventh area 217, and the eighth area 218.

[0026] 7, the plurality of electromagnet units 110 may be divided into a total of five areas: a first area 221 located at the center of the electromagnet device 100; a second area 222 surrounding the periphery of the first area 221 so as to include the first area 221; a third area 223 surrounding the periphery of the second area 222 so as to include the second area 222; a fourth area 224 surrounding the periphery of the third area 223 so as to include the third area 223; and a fifth area 225 located at the outermost periphery so as to include the fourth area 224. In the example of FIG. 7, for example, the controller 250 controls the electromagnet units 110 in order from the area located inside (center) to the area located outside (periphery), that is, in the order of the first area 221, the second area 222, the third area 223, the fourth area 224, and the fifth area 225. 5 and 6, good adhesion can be ensured between a thin object to be attracted, such as the metal mask 504, and the electromagnet device 100 or the substrate 502.

[0027] FIG. 8 is a diagram showing an example of the temporal relationship of the current flowing through the coil 114 of the electromagnet unit 110 in each area. Hereinafter, the area arrangement shown in FIG. 5 will be used as an example. As shown in FIG. 8, at time T 10 At time T 11 The coils 114 of the electromagnet units 110 in the third area 203 and the sixth area 206 are controlled to reach a predetermined maximum value at time T 10 and time T 11 Time T between 20 (i.e., the time from when the current I1 starts to be supplied to the coils 114 of the electromagnet units 110 in the fourth area 204 and the fifth area 205 until it reaches its maximum value), the current I2 starts to be supplied. Similar to the current I1, the current I2 gradually increases from a current value of zero until time T 21Similarly, the coils 114 of the electromagnet units 110 in the second area 202 and the seventh area 207 are controlled to reach a predetermined maximum value at time T 20 and time T 21 Time T between 30 At time T 31 The coils 114 of the electromagnet units 110 in the first area 201 and the eighth area 208 are controlled to reach a predetermined maximum value at time T 30 and time T 31 Time T between 40 The current I4 starts to be supplied at time T 41 In this way, by starting the supply of current to the coils 114 of the electromagnet units 110 belonging to a certain area (for example, the fourth area 204 and the fifth area 205) and the supply of current to the coils 114 of the electromagnet units 110 belonging to that area (for example, the third area 203 and the sixth area 206) between the time when the supply of current to the coils 114 of the electromagnet units 110 belonging to that area starts and the time when the supply of current to the coils 114 of the electromagnet units 110 belonging to that area reaches a predetermined value, it is possible to more effectively suppress the occurrence of bending when attracting a thin object to be attracted, and to further improve the adhesion of the object to be attracted.

[0028] Although the embodiments of the present invention have been described above based on several examples, the above-described embodiments of the invention are intended to facilitate understanding of the present invention and are not intended to limit the present invention. The present invention may be modified or improved without departing from the spirit thereof, and the present invention naturally includes equivalents thereof. Furthermore, any combination or omission of the components described in the claims and specification is possible within the scope of solving at least part of the above-described problems or achieving at least part of the effects. [Explanation of symbols]

[0029] 100 Electromagnetic device 105 Suction surface 110 Electromagnet Unit 112 York 114 Coil 116 Resin molding material 120 Insulation Layer 140 Cooling Plate 142 Water cooling piping 145 Heat Transfer Sheet 150 Upper housing 160 Lower housing 162 Beam 164 sectors 200 Electromagnet Control System 201~225 area 250 Controller 500 Organic electroluminescent device manufacturing equipment 502 board 504 Metal Mask 506 Evaporation Source 508 Chamber MP1, MP2 magnetic pole

Claims

1. York and a coil wound around the yoke; a housing that houses the yoke and the coil, the housing having an attraction surface to which an object is attracted by magnetic force; a heat insulating layer disposed between the tip of the yoke and the inner surface of the housing on the suction surface side, the heat insulating layer being configured as an air layer or a vacuum layer that does not contain liquid; a cooling plate disposed in contact with a surface of the yoke opposite to the tip end; An electromagnetic device comprising:

2. The electromagnetic device according to claim 1 , wherein the cooling capacity of the cooling plate is controlled in accordance with the amount of heat generated by the coil.

3. The electromagnetic device according to claim 1 or 2, further comprising a heat transfer member interposed between the yoke and the cooling plate.

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