Metal plate transfer device and metal plate transfer method

Abstract

To provide a metal plate shifting device and a metal plate shifting method, capable of suppressing deformation in accordance with shift of a metal plate in a manufacturing step of the metal plate.SOLUTION: A metal plate shifting device 1 for shifting a metal mask M as an example of a sheet-like metal plate sucked to a magnet, comprises: a porous sheet 10 that includes a contact surface 10S contacted to the metal mask M; a non-magnetic plate 20 that includes a supporting surface 20S for supporting a surface that is opposite to the contact surface 10S of a surface provided in the porous sheet 10; a magnet sucking part 30 that makes magnet force act on the metal mask M from a side opposite to a side where the porous sheet 10 is positioned against the non-magnetic plate 20; and an elevation part 40 that changes a distance between the non-magnetic plate 20 and the magnet sucking part 30. Hardness in the contact surface 10S is lower than that of the supporting surface 20S.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a metal plate transfer apparatus and a metal plate transfer method for transferring a magnet-adsorbable metal plate.

Background Art

[0002] A metal mask is an example of a metal plate, and is a sheet-shaped metal member having through-holes. Metal masks are used in the manufacture of organic EL displays, the manufacture of multilayer ceramic capacitors (MLCCs), and metal light-shielding plates for cameras that function as apertures against external light in camera units included in electronic devices.

[0003] For example, in the manufacture of organic EL displays, a metal mask is used for vapor deposition of an organic EL material on the surface of a substrate. The metal mask in this case includes through-holes each having a width of several tens of micrometers formed in a sheet-shaped metal plate having a thickness of several tens of micrometers. When transferring a metal mask, it is required to maintain the posture of the metal mask in a stable state so as not to cause deformation, damage or the like to the metal mask, and to transfer the metal mask between the transfer apparatus and another apparatus without applying an external force to the metal mask.

[0004] Patent Document 1 discloses, as an example of a technique for holding a sheet-shaped member, a holding jig including a base substrate having a ventilation path portion, and an adhesive layer disposed on the base substrate so as to block the ventilation path portion. A sheet-shaped member such as a flexible printed circuit board (FPC) is detachably adhered to the adhesive layer. In the technique described in Patent Document 1, in a state where the sheet-shaped member is adhered to the adhesive layer, pressurizing or suctioning gas through the ventilation path deforms the adhesive layer covering the ventilation path into a convex or concave shape. The sheet-shaped member adhered to the adhesive layer is peeled off in this manner, thereby delivering the sheet-shaped member.

Prior Art Literature

Patent Literature

[0005] [Patent Document 1] Japanese Patent Publication No. 2009-105226 [Overview of the project] [Problems that the invention aims to solve]

[0006] Because metal masks are thin and have fine shapes that define through-holes, they are easily deformed when external forces are applied to them during transfer and when the suction is released during handover. Therefore, when the technology of Patent Document 1 is applied to the transfer of a metal mask, there is a risk that the metal mask will be deformed by the external force applied when peeling the metal mask from the adhesive layer. It should be noted that the above problem is also common to metal plates other than metal masks that are easily deformed by external forces. [Means for solving the problem]

[0007] A metal plate transfer device for solving the above problems is a metal plate transfer device for transferring a sheet-like metal plate that is attracted to a magnet, comprising: a porous sheet having a contact surface that contacts the metal plate; a non-magnetic plate having a support surface that supports the surface of the porous sheet opposite to the contact surface; a magnetic adsorption unit that applies a magnetic force to the metal plate from the side opposite to the side on which the porous sheet is located relative to the non-magnetic plate; and a lifting unit that changes the distance between the non-magnetic plate and the magnetic adsorption unit, wherein the hardness of the contact surface is lower than the hardness of the support surface.

[0008] According to the above configuration, the strength of the magnetic force acting on the metal plate in contact with the contact surface changes as the magnetic adsorption part moves relative to the non-magnetic plate by the lifting mechanism. This allows the metal plate to be adsorbed and released without changing the relative position between the metal plate and the contact surface. As a result, local stress on the metal plate during adsorption and release is suppressed. Furthermore, the metal plate is adsorbed to the contact surface of the porous sheet, which has a lower hardness than the support surface of the non-magnetic plate. This suppresses deformation of the metal plate due to contact with foreign matter, even if foreign matter is interposed between the contact surface and the metal plate, compared to the case where the metal plate is adsorbed to a surface with a higher hardness than the contact surface, such as the support surface.

[0009] In the above-described metal plate transfer device, it is preferable that the porous sheet has open-cell pores and a porosity of 60% or more. With this configuration, the presence of open-cell pores in the porous sheet suppresses the formation of a sealed space between the metal plate and the contact surface. This suppresses the force acting on the metal plate that pulls it towards the contact surface due to the difference in air pressure between the space between the metal plate and the contact surface and atmospheric pressure when peeling the metal plate from the contact surface. As a result, the external force applied to the metal plate when peeling it from the contact surface can be reduced, and the metal plate can be easily peeled from the contact surface. Furthermore, the above-described effects can be suitably achieved by having a porosity of 60% or more in the porous sheet.

[0010] In the metal plate transfer device described above, it is preferable that the non-magnetic plate is provided with ventilation holes extending from the support surface. With this configuration, the non-magnetic plate having ventilation holes extending from the support surface allows the holes in the porous sheet that face the non-magnetic plate to be exposed to the atmosphere through the ventilation holes. Therefore, the formation of a sealed space between the contact surface of the metal plate and the porous sheet can be more reliably suppressed.

[0011] In the above-described metal plate transfer device, it is preferable that the contact surface has an Asker C hardness of 20 or less. By having an Asker C hardness of 20 or less on the contact surface, even if foreign matter is interposed between the contact surface and the metal plate, deformation of the metal plate due to contact with the foreign matter can be suppressed more reliably.

[0012] In the metal plate transfer device described above, the lifting unit moves the magnetic adsorption unit relative to the non-magnetic plate, thereby changing the distance between the non-magnetic plate and the magnetic adsorption unit. The position of the magnetic adsorption unit when the metal plate is attracted to the contact surface by the magnetic force of the magnetic adsorption unit is the adsorption position, and the position of the magnetic adsorption unit when the metal plate is not attracted to the contact surface by the magnetic force of the magnetic adsorption unit is the non-adsorption position. Preferably, the amount of movement of the magnetic adsorption unit when the lifting unit moves the magnetic adsorption unit from the adsorption position to the non-adsorption position is 2 mm or more. With the above configuration, by moving the magnetic adsorption unit located in the adsorption position by 2 mm or more, the magnetic force acting on the metal plate in contact with the contact surface can be sufficiently reduced.

[0013] In the metal plate transfer device described above, it is preferable that the magnetic adsorption part alternately applies a first magnetic force and a second magnetic force weaker than the first magnetic force in a one-dimensional direction along the contact surface. With this configuration, even if the metal plate is magnetically adsorbed while it is wavy, the portion of the waviness that is acted upon by the first magnetic force is preferentially adsorbed, causing the waviness to shrink as if being compressed. At the same time, the peaks of the waviness on the metal plate move to a position where the first magnetic force does not act and the second magnetic force acts, that is, a position where the magnetic force is relatively weaker. As a result, excessive compression of the waviness is suppressed, and the formation of creases at the peaks of the waviness is suppressed.

[0014] In the metal plate transfer device described above, the porous sheet may have openings that penetrate in the thickness direction, and when the metal plate and the porous sheet are brought into contact, the through-holes in the metal plate may be located inside the openings in the planar direction of the metal plate. With this configuration, the portion of the metal plate that defines the through-holes will not be in contact with the porous sheet. This makes it possible to suppress the application of external force to the portion of the metal plate that defines the through-holes due to foreign matter interposed between the contact surface of the metal plate and the porous sheet.

[0015] A method for transferring a metal plate to solve the above problems includes: bringing a sheet-like metal plate that is attracted to a magnet into contact with a contact surface of a porous sheet supported by a support surface of a non-magnetic plate, which is opposite to the surface in contact with the non-magnetic plate and has a lower hardness than the support surface; applying the magnetic force of a magnetic adsorption part that attracts the metal plate to the contact surface to the metal plate from the side opposite to the side where the porous sheet is located relative to the non-magnetic plate; and changing the distance between the non-magnetic plate and the magnetic adsorption part.

[0016] A metal plate transfer method to solve the above problem involves bringing a first surface of a sheet-like metal plate that is attracted to a magnet into contact with a first contact surface, which is one of the surfaces of a first porous sheet supported by a first support surface of a first non-magnetic plate, the surface opposite to the surface in contact with the first non-magnetic plate, and having a lower hardness than the first support surface; applying the magnetic force of a first magnetic adsorption part that attracts the metal plate to the first contact surface to the metal plate from the side opposite to the side where the first porous sheet is located relative to the first non-magnetic plate; and maintaining the state in which the first surface is in contact with the first porous sheet. The present invention includes bringing into contact with a second contact surface of the metal plate, which is the surface of the second porous sheet supported by a second support surface of the second non-magnetic plate, that is opposite to the surface in contact with the second non-magnetic plate and has a lower hardness than the second support surface; applying the magnetic force of the second magnetic adsorption portion that attracts the metal plate to the second contact surface to the metal plate from the side opposite to the side of the second porous sheet that is located relative to the second non-magnetic plate; and increasing the distance between the first non-magnetic plate and the first magnetic adsorption portion.

[0017] According to the above method, the state in which the metal plate is attracted changes from a state where the first surface of the metal plate is attracted to the first contact surface to a state where the second surface of the metal plate is attracted to the second contact surface, thus allowing the surface to be attracted to the metal plate to be reversed. Furthermore, since the posture of the metal plate is kept constant during the reversal operation, deformation of the metal plate can be suppressed. The first surface of the metal plate is then attracted to the first contact surface, which has a lower hardness than the first support surface. As a result, compared to the case in which the metal plate is attracted to a surface with a higher hardness than the first contact surface, such as the first support surface, deformation of the metal plate due to contact with foreign matter can be suppressed even if foreign matter is interposed between the first contact surface and the first surface of the metal plate. Similarly, compared to the case in which the metal plate is attracted to a surface with a higher hardness than the second contact surface, such as the second support surface, deformation of the metal plate due to contact with foreign matter can be suppressed even if foreign matter is interposed between the second contact surface and the second surface of the metal plate. [Effects of the Invention]

[0018] According to the present invention, in the manufacturing process of a metal plate, deformation accompanying the transfer of the metal plate can be suppressed. [BRIEF DESCRIPTION OF THE DRAWINGS]

[0019] [Figure 1] Figure 1 is a schematic diagram illustrating the configuration of the metal plate transfer device according to the first embodiment. [Figure 2] Figure 2 is a schematic diagram showing the metal plate transfer device in a state where the magnetic attraction unit is located at the non-attraction position and the contact surface of the porous sheet is in contact with the metal mask. [Figure 3] Figure 3 is a schematic diagram showing the metal plate transfer device in a state where the magnetic attraction unit is moved from the state shown in Figure 2 to the attraction position. [Figure 4] Figure 4 is a schematic diagram showing a state where the metal plate transfer device that has attracted the metal mask is lifted from the state shown in Figure 3. [Figure 5] Figure 5 is a schematic diagram showing a first magnetic force and a second magnetic force acting on the metal mask from the magnetic attraction unit. [Figure 6] Figure 6 is a schematic diagram showing a state where a wavy deformed metal mask is placed on a stage. [Figure 7] Figure 7 is a schematic diagram showing a state where the metal mask in the state shown in Figure 6 is attracted by the metal plate transfer device. [Figure 8] Figure 8 is a schematic diagram showing the metal mask in a state where the waviness generated in the metal mask has moved from a position where the first magnetic force acts to a position where the second magnetic force acts. [Figure 9] Figure 9 is an exploded perspective view illustrating a modified example of the metal plate transfer device according to the first embodiment. [Figure 10] Figure 10 is a schematic diagram illustrating the configuration of the metal plate transfer device according to the second embodiment. [Figure 11] Figure 11 is a schematic diagram showing a first metal plate transfer device and a second metal plate transfer device used in the third embodiment. [Figure 12] Figure 12 is a schematic diagram showing the step of transferring the metal mask attracted by the first metal plate transfer device to the second metal plate transfer device. [Figure 13]Figure 13 is a schematic diagram showing the state in which the metal mask is adsorbed onto the second metal plate transfer device. [Figure 14] Figure 14 is a schematic diagram showing the configuration of the metal plate transfer device of Comparative Example 1. [Figure 15] Figure 15 is a schematic diagram showing the configuration of the metal plate transfer device of Comparative Example 2. [Figure 16] Figure 16 is a schematic diagram showing the configuration of the metal plate transfer device of Comparative Example 3. [Figure 17] Figure 17 is a schematic diagram showing the configuration of the metal plate transfer device of Comparative Example 4. [Figure 18] Figure 18 is a schematic diagram showing the first metal plate transfer device and the second metal plate transfer device used in Comparative Example 5. [Modes for carrying out the invention]

[0020] [First Embodiment] The first embodiment of the metal plate transfer device will be described below with reference to Figures 1 to 9. [Metal Mask] As shown in Figure 1, a metal mask M, which is an example of a metal plate, is placed on the flat surface of the stage S. The metal mask M is a rectangular, sheet-like metal that is attracted to magnets. For example, the metal mask M has a length of 300 mm to 3000 mm, a width of 50 mm to 400 mm, and a thickness of 10 μm to 50 μm. Multiple through holes of a predetermined shape are arranged in the center of the metal mask M. The through holes in the metal mask M may be circular, square, or elliptical. The maximum width of the opening of the through holes is, for example, 20 μm to 100 μm. The metal mask M is used, for example, in the manufacture of organic EL displays. However, the metal mask M may also be used for depositing materials other than organic EL materials.

[0021] The material constituting the metal mask M includes a ferromagnetic metal that is attracted to magnets. The ferromagnetic metal is selected from the group consisting of, for example, iron, cobalt, nickel, and alloys containing any of these. An example of an alloy is Invar material containing iron and nickel. The Vickers hardness of the metal mask M made of Invar material is, for example, approximately 165 HV to 175 HV.

[0022] [Metal plate transfer device] The metal plate transfer device 1 of the first embodiment is a device for moving a metal plate placed in an arbitrary location to another location during the manufacturing, inspection, or storage of metal plates that are attracted to magnets. The metal plate transferred by the metal plate transfer device 1 is, for example, a metal mask M, but any sheet-like metal plate that is attracted to magnets can be transferred by the metal plate transfer device 1. Examples of metal plates transferred by the metal plate transfer device 1 include lead frames and shadow masks.

[0023] The metal plate transfer device 1 is configured to be portable by an operator, for example, but it may also be configured to be moved by a mechanical moving mechanism such as a robotic arm or an electric slider. The metal plate transfer device 1 comprises a porous sheet 10, a non-magnetic plate 20, a magnetic adsorption unit 30, and a lifting unit 40.

[0024] [Porous Sheet] The porous sheet 10 is a sheet-like member having pores (voids) inside. The porous sheet 10 has a contact surface 10S. The contact surface 10S is the surface of the porous sheet 10 that is in contact with the metal mask M. The porous sheet 10 is supported on the side opposite to the contact surface 10S by a support surface 20S provided by the non-magnetic plate 20. The contact surface 10S is larger than the metal mask M. That is, when the contact surface 10S and the metal mask M are in contact, the outer edge of the metal mask M is located inside the outer edge of the contact surface 10S. In Figure 1, the porous sheet 10 is shown with dots.

[0025] The porous sheet 10 is, for example, a porous body made of an organic material. The material constituting the porous sheet 10 includes, for example, at least one of the following: a copolymer foam of acrylic, urethane, and rubber, and a polyurethane foam. As an example, the porous sheet 10 is a polyurethane foam (urethane foam). The thickness of the porous sheet 10 is, for example, 0.5 mm or more and 1.0 mm or less. The porosity of the porous sheet 10 is, for example, 60% or more. The porosity of the porous sheet 10 is the ratio of the volume of pores contained in the porous sheet 10 to the apparent volume of the entire porous sheet 10. The apparent volume of the entire porous sheet 10 is the sum of the volume of the material constituting the porous sheet 10 and the volume of pores contained in the porous sheet 10.

[0026] Preferably, at least a portion of the pores in the porous sheet 10 are open cells. The porous sheet 10 has breathability due to having open cell pores. That is, the porous sheet 10 has pores that communicate from one surface of the porous sheet 10 through the interior of the porous sheet 10 to another surface or the same surface.

[0027] An example of a material constituting the contact surface 10S of the porous sheet 10 is one that has a lower hardness than the Invar material constituting the metal mask M and the material constituting the support surface 20S of the non-magnetic plate 20. The fact that the contact surface 10S has a lower hardness than the metal mask M means that any point on the contact surface 10S that contacts the metal mask M has a lower hardness than any point on the metal mask M. The repulsive force at the contact surface 10S is weaker than that at the support surface 20S of the non-magnetic plate 20. The shock absorption at the contact surface 10S is higher than that at the support surface 20S of the non-magnetic plate 20. It is preferable that the Asker C hardness (hereinafter simply referred to as Asker C hardness) of the contact surface 10S of the porous sheet 10, measured by the Type C test method in the spring hardness test compliant with JIS K7312-1996, is C20 or less.

[0028] In the manufacturing process of the metal mask M, residue from the resist mask used to process through holes in the substrate of the metal mask M, and processing residue from the substrate generated by wet etching, are foreign matter that may adhere to the metal mask M. In the inspection process of the metal mask M, dust or dirt in the manufacturing or inspection environment is also foreign matter that may adhere to the metal mask M.

[0029] Since the contact surface 10S has a lower hardness than the support surface 20S, the contact surface 10S can absorb irregularities caused by foreign matter interposed between the contact surface 10S and the metal mask M, compared to the case where the metal mask M is adsorbed to the support surface 20S. Therefore, even if foreign matter is interposed between the contact surface 10S and the metal mask M, deformation of the metal mask M due to contact with the foreign matter can be suppressed. In particular, if the Asker C hardness of the contact surface 10S of the porous sheet 10 is C20 or less, deformation of the metal mask M due to contact with foreign matter can be suppressed more reliably.

[0030] [Non-magnetic plate] The non-magnetic plate 20 is a rectangular plate-shaped member made of a material that does not attract magnets. The material constituting the non-magnetic plate 20 is a non-magnetic metal or a non-magnetic inorganic compound. Examples of non-magnetic metals include aluminum, stainless steel, or copper. Examples of non-magnetic inorganic compounds include silicon oxide or aluminum oxide. From the viewpoint of reducing the weight of the metal plate transfer device 1, aluminum, which has high deformation resistance per unit weight, is preferred as the material constituting the non-magnetic plate 20. The thickness of the non-magnetic plate 20 is, for example, 0.5 mm or more and 1.0 mm or less.

[0031] The non-magnetic plate 20 is provided with a flat support surface 20S that supports the porous sheet 10. The support surface 20S is larger than the metal mask M and has an area equal to or larger than that of the porous sheet 10. For example, if the non-magnetic plate 20 is made of anodized aluminum, the Vickers hardness of the support surface 20S of the non-magnetic plate 20, measured in accordance with JIS Z2244-1:2020, is approximately 200 HV to 300 HV.

[0032] [Magnetic adsorption part] The magnetic adsorption section 30 is positioned on the side opposite to the side of the non-magnetic plate 20 where the porous sheet 10 is located. The magnetic adsorption section 30 comprises a plurality of permanent magnet sheets 31 and a support plate 32. The permanent magnet sheets 31 are sheet-shaped permanent magnets composed of, for example, Alnico magnets, ferrite magnets, or neodymium magnets. The permanent magnet sheets 31 have a width that is sufficiently smaller than the length (longitudinal dimension) of the metal mask M. In the magnetic adsorption section 30, the plurality of permanent magnet sheets 31 are arranged in a line with predetermined intervals relative to the support plate 32 along the longitudinal direction of the metal mask M. The plurality of permanent magnet sheets 31 are arranged intermittently with gaps along the longitudinal direction of the metal mask M. Note that the longitudinal direction of the metal mask M is an example of a one-dimensional direction along the contact surface 10S. Also, in Figure 1, the permanent magnet sheets 31 are shown with hatching.

[0033] The support plate 32 is made of a non-magnetic metal such as aluminum or stainless steel, or a non-magnetic inorganic compound. The support plate 32 is, for example, a rectangular plate. The support plate 32 may also have cutouts for weight reduction, such as those found in perforated metal. The support plate 32 is attached to the lifting section 40.

[0034] The magnetic adsorption unit 30 applies the magnetic force of the permanent magnet sheet 31 to the metal mask M from the side opposite to the side where the porous sheet 10 is located relative to the non-magnetic plate 20, through the non-magnetic plate 20 and the porous sheet 10. The magnetic force of the permanent magnet sheet 31 acts on the metal mask M, causing the metal mask M to be attracted toward the contact surface 10S of the porous sheet 10. As a result, the metal mask M is adsorbed and held by the metal plate transfer device 1.

[0035] The surface magnetic flux density of the permanent magnet sheet 31 is preferably 50 mT or more and 200 mT or less. A surface magnetic flux density of 50 mT or more allows sufficient magnetic force to be applied to attract the metal mask M to the contact surface 10S. A surface magnetic flux density of 200 mT or less prevents the magnetic force of the permanent magnet sheet 31 from acting over an excessively long distance. This shortens the distance traveled from the adsorption position to the non-adsorption position, thereby reducing the time required to switch between the adsorption and non-adsorption positions. The surface magnetic flux density of the permanent magnet sheet 31 can be appropriately determined according to the size and weight of the metal mask M, the thickness of the porous sheet 10 and the non-magnetic plate 20, and the size and number of permanent magnet sheets 31.

[0036] [Lifting section] The lifting unit 40 is positioned on the non-magnetic plate 20 on the side opposite to the support surface 20S. The lifting unit 40 moves the magnetic adsorption unit 30 relative to the non-magnetic plate 20 so as to change the distance between the non-magnetic plate 20 and the magnetic adsorption unit 30. When the lifting unit 40 brings the magnetic adsorption unit 30 closer to the non-magnetic plate 20, the magnetic force of the permanent magnet sheet 31 acting on the metal mask M is strengthened. Conversely, when the lifting unit 40 moves the magnetic adsorption unit 30 further away from the non-magnetic plate 20, the magnetic force of the permanent magnet sheet 31 acting on the metal mask M is weakened. Preferably, the direction in which the lifting unit 40 moves the magnetic adsorption unit 30 is in a direction in which the change in magnetic force acting on the metal mask M is uniform at the edge of the metal mask M, for example, in the direction normal to the support surface 20S.

[0037] The mechanism by which the lifting unit 40 moves the magnetic adsorption unit 30 is configured to move the support plate 32 by means of an electric actuator equipped with a motor or an air actuator equipped with a cylinder. The mechanism by which the lifting unit 40 moves the magnetic adsorption unit 30 may also be configured to move the support plate 32 by manual operation, or it may be configured to have a compression spring to assist in the movement of the support plate 32. From the viewpoint of suppressing the increase in size of the metal plate transfer device 1 and from the viewpoint of reducing the weight of the metal plate transfer device 1, a configuration in which the support plate 32 is moved by manual operation is preferred for the lifting unit 40.

[0038] The position of the magnetic adsorption part 30 when the metal mask M is in contact with the contact surface 10S of the porous sheet 10 and a magnetic force acts on the metal mask M to such an extent that it is attracted to the contact surface 10S against its own weight is the adsorption position. The position of the magnetic adsorption part 30 when the metal mask M is in contact with the contact surface 10S of the porous sheet 10 and the metal mask M is not attracted to the contact surface 10S by the magnetic force of the permanent magnet sheet 31 is the non-adsorption position. The lifting and lowering unit 40 switches between the state in which the metal mask M is attracted to the contact surface 10S and the state in which the metal mask M is not attracted to the contact surface 10S by moving the magnetic adsorption part 30 between the adsorption position and the non-adsorption position. Note that Figure 1 illustrates the state in which the magnetic adsorption part 30 is in the adsorption position.

[0039] At the adsorption position, it is preferable that the permanent magnet sheet 31 and the non-magnetic plate 20 are in contact with each other, from the viewpoint of further strengthening the magnetic force acting on the metal mask M. However, at the adsorption position, the permanent magnet sheet 31 and the non-magnetic plate 20 may be separated, as long as a magnetic force acts on the metal mask M to such an extent that it is attracted to the contact surface 10S against its own weight.

[0040] When the lifting unit 40 moves the magnetic adsorption unit 30 from the adsorption position to the non-adsorption position, the amount of movement of the magnetic adsorption unit 30 is preferably 2 mm or more, from the viewpoint of further weakening the magnetic force acting on the metal mask M. That is, it is preferable that the distance between the non-magnetic plate 20 and the magnetic adsorption unit 30 is 2 mm or more in the non-adsorption position. By moving the magnetic adsorption unit 30 relative to the non-magnetic plate 20 such that the distance between the non-magnetic plate 20 and the magnetic adsorption unit 30 is 2 mm or more in the non-adsorption position, the magnetic force acting on the metal mask M in contact with the contact surface 10S can be sufficiently reduced. Furthermore, when the lifting unit 40 moves the magnetic adsorption unit 30 from the adsorption position to the non-adsorption position, the amount of movement of the magnetic adsorption unit 30 is preferably 50 mm or less. By making the amount of movement of the magnetic adsorption unit 30 50 mm or less, the amount of movement between the adsorption position and the non-adsorption position can be shortened, thereby shortening the time required to switch between the adsorption position and the non-adsorption position, and also suppressing the increase in size of the metal plate transfer device 1.

[0041] [Method for transferring metal plates] The procedure for transferring the metal mask M, which is installed on stage S, will be explained below with reference to Figures 2 to 4.

[0042] As shown in Figure 2, when transferring the metal mask M using the metal plate transfer device 1, first, the magnetic adsorption part 30 is moved away from the non-magnetic plate 20 by the lifting part 40, thereby moving the magnetic adsorption part 30 to a non-adsorption position. In this state, the metal plate transfer device 1 is moved so that the contact surface 10S of the porous sheet 10 comes into contact with the metal mask M placed on the stage S. By bringing the contact surface 10S into contact with the metal mask M while the magnetic adsorption part 30 is in a non-adsorption position, it is possible to prevent the metal mask M from being unintentionally adsorbed during the process of bringing the contact surface 10S closer to the metal mask M. Alternatively, the contact surface 10S may be brought into contact with the metal mask M while the magnetic adsorption part 30 is in an adsorption position.

[0043] As shown in Figure 3, the magnetic adsorption part 30 is then moved to the adsorption position by the lifting part 40 bringing it closer to the non-magnetic plate 20. As a result, the metal mask M placed on the stage S is attracted to the contact surface 10S of the porous sheet 10. Therefore, the metal mask M is adsorbed onto the metal plate transfer device 1.

[0044] As shown in Figure 4, with the metal mask M attached to the metal plate transfer device 1, the metal plate transfer device 1 is lifted and then moved to an arbitrary location where the metal mask M will be transferred. Then, with the metal mask M, which is attached to the metal plate transfer device 1, placed in the new location, the magnetic adsorption part 30 is moved away from the non-magnetic plate 20 by the lifting part 40, thereby moving the magnetic adsorption part 30 to a non-adsorption position. This releases the metal mask M from adsorption. Then, by moving the metal plate transfer device 1, the metal mask M is detached from the contact surface 10S. The metal mask M is transferred through the above procedure.

[0045] When the metal mask M and the contact surface 10S are in contact, some of the pores in the porous sheet 10 are blocked by the metal mask M at the openings located on the contact surface 10S. Because the porous sheet 10 has open-cell pores, the pores blocked by the metal mask M are able to communicate with the atmosphere through the inside of the porous sheet 10. In the first embodiment, at least some of the pores blocked by the metal mask M are able to communicate with the atmosphere through, for example, openings located on the part of the contact surface 10S that is not blocked by the metal mask M. Also in the first embodiment, at least some of the pores blocked by the metal mask M are able to communicate with the atmosphere through, for example, openings located on the side surface of the porous sheet 10 that is not in contact with the non-magnetic plate 20.

[0046] Therefore, because the porous sheet 10 has open-cell pores, the formation of a sealed space between the metal mask M and the contact surface 10S is suppressed. As a result, when peeling the metal mask M from the contact surface 10S, the force that would otherwise act on the metal mask M to pull it towards the contact surface 10S due to the difference in air pressure between the space between the metal mask M and the contact surface 10S and atmospheric pressure is suppressed. Consequently, when peeling the metal mask M from the contact surface 10S, the external force applied to the metal mask M can be reduced, and the metal mask M can be easily peeled from the contact surface 10S. Furthermore, the above effects can be suitably achieved if the porosity of the porous sheet 10 is 60% or more.

[0047] [Placement of permanent magnet sheets] The effects of the arrangement of the permanent magnet sheet 31 will be explained below with reference to Figures 5 to 8. As shown in Figure 5, the multiple permanent magnet sheets 31 are intermittently arranged along the longitudinal direction of the metal mask M, so that a first magnetic force MF1 and a second magnetic force MF2, which is weaker than the first magnetic force MF1, act alternately on the metal mask M along the longitudinal direction of the metal mask M.

[0048] For example, a first magnetic force MF1 acts on the portion of the metal mask M that faces the permanent magnet sheet 31 via the porous sheet 10 and the non-magnetic plate 20. A second magnetic force MF2 acts on the portion of the metal mask M that does not face the permanent magnet sheet 31 via the porous sheet 10 and the non-magnetic plate 20. The portion of the metal mask M on which the first magnetic force MF1 acts is preferentially attracted toward the contact surface 10S than the portion on which the second magnetic force MF2 acts.

[0049] As shown in Figure 6, for example, a metal mask M placed on a stage S may develop undulations W (wrinkles). When undulations W occur in a metal mask M, the undulations W tend to take on a shape that extends in a one-dimensional direction intersecting the longitudinal direction of the metal mask M. When a contact surface 10S is brought into contact with a metal mask M that has undulations W, the position of the peak of the undulation W may shift, or the undulation W may separate into two. For example, the undulations W may disappear when they move to the edge of the metal mask M. In addition, the metal mask M may be magnetically attracted with some of the undulations W remaining.

[0050] As shown in Figure 7, in a metal mask M where undulation W occurs, when the first magnetic force MF1 of the permanent magnet sheet 31 acts on the undulation W, its height and width are reduced as if the undulation W were being compressed. At the same time, the peak of the undulation W moves to a position where the first magnetic force MF1 does not act and the second magnetic force MF2 acts.

[0051] As shown in Figure 8, when the peak of the wave W moves to the position where the second magnetic force MF2 acts, the width of the wave W increases as the magnetic constriction on the wave W weakens. If excessive magnetic force acts on the wave W, the wave W may be excessively constricted, causing a crease to form at the peak of the wave W. In this regard, the alternating action of the first magnetic force MF1 and the second magnetic force MF2 on the metal mask M causes the peak of the wave W to move due to the first magnetic force MF1 to the position where the second magnetic force MF2, which is weaker than the first magnetic force MF1, acts, i.e., a position with relatively weaker magnetic force. This suppresses the formation of a crease at the peak of the wave W due to excessive magnetic force acting on the wave W.

[0052] [Effects of the First Embodiment] According to the first embodiment described above, the following effects can be obtained. (1-1) The strength of the magnetic force acting on the metal mask M in contact with the contact surface 10S changes as the magnetic adsorption part 30 moves relative to the non-magnetic plate 20 by the lifting part 40. This makes it possible to adsorb and release the metal mask M without changing the relative position between the metal mask M and the contact surface 10S. As a result, local stress acting on the metal mask M during the adsorption and release of the metal mask M is suppressed.

[0053] (1-2) When the magnetic force of the magnetic adsorption part 30 acts on the metal mask M, the metal mask M is adsorbed onto the contact surface 10S of the porous sheet 10. As a result, compared to the case where the metal mask M is adsorbed onto a surface having a higher hardness than the contact surface 10S, such as the support surface 20S, deformation of the metal mask M due to contact with foreign matter can be suppressed even if foreign matter is interposed between the contact surface 10S and the metal mask M.

[0054] (1-3) By using the metal plate transfer device 1, if the metal mask M is smaller than the contact surface 10S, the entire surface of the metal mask M can be adsorbed and held regardless of the size of the metal mask M.

[0055] (1-4) Because the porous sheet 10 has open-cell pores, the force that attracts the metal mask M to the contact surface 10S when peeling the metal mask M from the contact surface 10S can be suppressed. As a result, the external force applied to the metal mask M when peeling the metal mask M from the contact surface 10S can be reduced, and the metal mask M can be easily peeled from the contact surface 10S. Furthermore, the above effects can be suitably exhibited if the porosity of the porous sheet 10 is 60% or more.

[0056] (1-5) The Asker C hardness of the contact surface 10S of the porous sheet 10 is C20 or less, so that even if foreign matter is interposed between the contact surface 10S and the metal mask M, deformation of the metal mask M due to contact with the foreign matter can be suppressed more reliably.

[0057] (1-6) When the lifting unit 40 moves the magnetic adsorption unit 30 from the adsorption position to the non-adsorption position, the amount of movement of the magnetic adsorption unit 30 is 2 mm or more, which sufficiently reduces the magnetic force acting on the metal mask M when it is in contact with the contact surface 10S.

[0058] (1-7) By arranging multiple permanent magnet sheets 31 intermittently, a first magnetic force MF1 and a second magnetic force MF2, which is weaker than the first magnetic force MF1, act alternately on the metal mask M along the longitudinal direction of the metal mask M. As a result, even if waviness W occurs in the metal mask M, excessive compression of the waviness W is suppressed. Therefore, the formation of folds at the peaks of the waviness W can be suppressed.

[0059] [Example of modification of the first embodiment] Furthermore, the first embodiment described above can be implemented with the following modifications. - If the configuration makes it difficult for the metal mask M, which is attracted by the metal plate transfer device 1, to undulate W, then instead of a configuration in which the first magnetic force MF1 and the second magnetic force MF2 are applied alternately to the metal mask M, a configuration in which a uniform magnetic force is applied to the metal mask M may be used. Also, in order to prevent the longitudinal center of the metal mask M from sagging, the magnetic force acting on the longitudinal center of the metal mask M may be stronger than the magnetic force acting on the longitudinal ends of the metal mask M. Furthermore, in order to more reliably attract the longitudinal ends of the metal mask M, the magnetic force acting on the longitudinal ends of the metal mask M may be stronger than the magnetic force acting on the longitudinal center of the metal mask M.

[0060] The configuration for alternately applying the first magnetic force MF1 and the second magnetic force MF2 to the metal mask M is not limited to a configuration in which multiple permanent magnet sheets 31 are arranged intermittently. For example, a single permanent magnet sheet 31 having a larger area than the metal mask M may have multiple intermittently arranged recesses extending in a direction intersecting the longitudinal direction of the metal mask M. In this case, the distance between the portion of the permanent magnet sheet 31 with recesses and the metal mask M becomes greater than the distance between the portion without recesses and the metal mask M. Therefore, the first magnetic force MF1 and the second magnetic force MF2 act alternately due to the difference in distance of the permanent magnet sheet 31 relative to the metal mask M.

[0061] The direction in which the first magnetic force MF1 and the second magnetic force MF2 alternately act on the metal mask M may be any one-dimensional direction along the contact surface 10S, for example, a one-dimensional direction along the contact surface 10S that intersects with the longitudinal direction of the metal mask M.

[0062] The amount of movement of the magnetic adsorption part 30 when the lifting unit 40 moves the magnetic adsorption part 30 from the adsorption position to the non-adsorption position may be less than 2 mm, provided that the magnetic force acting on the metal mask M in contact with the contact surface 10S is sufficiently reduced. The amount of movement of the magnetic adsorption part 30 when moving the magnetic adsorption part 30 from the adsorption position to the non-adsorption position can be appropriately determined according to, for example, the surface magnetic flux density of the permanent magnet sheet 31, the number of permanent magnet sheets 31, the size and weight of the metal mask M, etc.

[0063] Even if foreign matter is interposed between the contact surface 10S and the metal mask M, the Asker C hardness of the contact surface 10S may be greater than C20 if the contact surface 10S can absorb the irregularities caused by the foreign matter.

[0064] The pores of the porous sheet 10 may be closed cells. In this case, the contact surface 10S may have an uneven shape so that a sealed space is not formed between the metal mask M and the contact surface 10S. The pores of the porous sheet 10 may also have both open-cell and closed-cell pores. Furthermore, the porosity of the porous sheet 10 may be less than 60% as long as no excessive external force is applied to the metal mask M when peeling it from the contact surface 10S.

[0065] Instead of the lifting unit 40 moving the magnetic adsorption unit 30 relative to the non-magnetic plate 20, the lifting unit 40 may be configured to move the non-magnetic plate 20 relative to the magnetic adsorption unit 30. Alternatively, the lifting unit 40 may be configured to move both the non-magnetic plate 20 and the magnetic adsorption unit 30 in such a way that the distance between the non-magnetic plate 20 and the magnetic adsorption unit 30 is changed. In other words, the lifting unit 40 can be configured to change the distance between the non-magnetic plate 20 and the magnetic adsorption unit 30 by moving at least one of the non-magnetic plate 20 and the magnetic adsorption unit 30.

[0066] As shown in Figure 9, the porous sheet 10 may have openings 11. The openings 11 are portions that penetrate the porous sheet 10 in the thickness direction and do not come into contact with the metal mask M when the porous sheet 10 is brought into contact with the metal mask M. The openings 11 are sufficiently larger than the holes created by foaming during the manufacturing of the porous sheet 10. The openings 11 are larger than, for example, the area in the metal mask M where multiple through-holes MH are arranged. The shape of the openings 11 is not limited and may be rectangular, circular, or elliptical, for example. In Figure 9, the area where multiple through-holes MH are arranged is indicated by dots.

[0067] The porous sheet 10, which has openings 11, does not come into contact with the portion of the metal mask M that demarcates the through-holes MH, but comes into contact with other portions of the metal mask M. For example, when the metal mask M and the porous sheet 10 are brought into contact, the multiple through-holes MH of the metal mask M are located inside the openings 11 in the planar direction of the metal mask M. The planar direction of the metal mask M is a two-dimensional direction perpendicular to the thickness direction of the metal mask M.

[0068] In the metal mask M, the portion that demarcates the through-hole MH is a portion that is easily deformed by external forces. By providing openings 11 in the porous sheet 10, for example, it is possible to suppress the application of external forces caused by foreign matter interposed between the metal mask M and the contact surface 10S of the porous sheet 10 to the portion that demarcates the through-hole MH in the metal mask M. If openings 11 are not provided in the porous sheet 10, the entire surface of the metal mask M can be supported by the porous sheet 10. This allows the metal mask M to be held and moved in a stable state.

[0069] The size of the opening 11 may be such that, for example, when the metal mask M and the porous sheet 10 are in contact, some of the multiple through-holes MH in the metal mask M are located inside the opening 11 in the planar direction of the metal mask M. Alternatively, the size of the opening 11 may be such that a portion of at least one of the multiple through-holes MH in the metal mask M is located inside the opening 11. In this case, when the metal mask M and the porous sheet 10 are in contact, it is possible to suppress the application of external force due to foreign matter interposed between the contact surface 10S of the metal mask M and the porous sheet 10 to the portion of the metal mask M located inside the opening 11.

[0070] As shown in Figure 9, if the porous sheet 10 has an opening 11, the magnetic force acting on the portion of the metal mask M that does not come into contact with the porous sheet 10 may be weakened in order to suppress deformation due to magnetic force in that portion. For example, the permanent magnet sheet 31 may be arranged so that the opening 11 and the permanent magnet sheet 31 do not overlap in the direction in which the porous sheet 10, the non-magnetic plate 20, and the magnetic adsorption portion 30 are aligned. By arranging the permanent magnet sheet 31 in the magnetic adsorption portion 30 so as not to correspond to the opening 11, the magnetic force acting on the portion of the metal mask M that does not come into contact with the porous sheet 10 can be weakened. Even if the porous sheet 10 has an opening 11, the permanent magnet sheet 31 may be placed at a position corresponding to the opening 11 so that the portion of the metal mask M that does not come into contact with the porous sheet 10 does not become excessively loose.

[0071] [Second Embodiment] A second embodiment of the metal plate transfer device will be described below with reference to Figure 10. As shown in Figure 10, the metal plate transfer device 2 of the second embodiment has the same configuration as the metal plate transfer device 1 of the first embodiment, except that the non-magnetic plate 20 is provided with ventilation holes 20H.

[0072] The non-magnetic plate 20 is provided with a plurality of ventilation holes 20H. The ventilation holes 20H extend from the support surface 20S. The ventilation holes 20H penetrate in the thickness direction of the non-magnetic plate 20. The shape of the ventilation holes 20H can be any shape, for example, square holes including round holes, oval holes, elliptical holes, square holes, and hexagonal holes. The arrangement of the ventilation holes 20H may be random, for example, or one or more rows of ventilation holes 20H arranged intermittently at predetermined intervals. The non-magnetic plate 20 may be, for example, a perforated metal in which ventilation holes 20H of a predetermined shape are regularly arranged.

[0073] [Operation of the second embodiment] Because the non-magnetic plate 20 is equipped with ventilation holes 20H, a portion of the holes in the porous sheet 10 that face the non-magnetic plate 20 are made accessible to the atmosphere through the ventilation holes 20H. In other words, the ventilation holes 20H function as ventilation channels that allow the holes in the porous sheet 10 to communicate with the atmosphere. As a result, compared to the configuration of the first embodiment, the formation of a sealed space between the metal mask M and the contact surface 10S of the porous sheet 10 can be suppressed more reliably.

[0074] The aperture ratio of the non-magnetic plate 20 is preferably 20% or more and 50% or less. The aperture ratio of the non-magnetic plate 20 is the ratio of the total area of ​​the multiple ventilation holes 20H to the area of ​​the shape demarcated by the outer edge of the support surface 20S when viewed from a viewpoint facing the support surface 20S. If the aperture ratio of the non-magnetic plate 20 is 20% or more, the ventilation holes 20H function as ventilation channels, effectively suppressing the formation of a sealed space between the metal mask M and the contact surface 10S of the porous sheet 10. If the aperture ratio of the non-magnetic plate 20 is 50% or less, it is possible to suppress an excessive decrease in the mechanical strength of the non-magnetic plate 20 due to the formation of ventilation holes 20H.

[0075] [Effects of the second embodiment] (2-1) The ventilation holes 20H in the non-magnetic plate 20 allow the pores in the porous sheet 10 to communicate with the atmosphere, thereby more reliably suppressing the formation of a sealed space between the metal mask M and the contact surface 10S of the porous sheet 10. As a result, the external force applied to the metal mask M when peeling it from the contact surface 10S can be reduced more reliably, and the metal mask M can be peeled from the contact surface 10S more easily. The effects of (1-1) to (1-7) described above can also be obtained in the metal plate transfer device 2 of the second embodiment.

[0076] [Example of modification of the second embodiment] Furthermore, the second embodiment described above can be implemented with the following modifications. • The same modifications as in the first embodiment can be applied to the metal plate transfer device 2 of the second embodiment. Furthermore, even if the non-magnetic plate 20 has ventilation holes 20H, the holes in the porous sheet 10 may be closed cells. In this case, for example, holes that penetrate the porous sheet 10 in the thickness direction may be formed separately from the holes formed by foaming during the manufacturing of the porous sheet 10. In this case, the ventilation holes 20H of the non-magnetic plate 20 allow the holes that penetrate the porous sheet 10 in the thickness direction to communicate with the atmosphere, thereby preventing the formation of a sealed space between the metal mask M and the contact surface 10S of the porous sheet 10.

[0077] [Third Embodiment] The third embodiment of the metal plate transfer device will be described below with reference to Figures 11 to 13. In the third embodiment, as an example of a method for transferring the metal mask M, a method of reversing the front and back sides of the metal mask M, which is held by suction on the metal plate transfer devices 2, will be described using two metal plate transfer devices 2.

[0078] As shown in Figure 11, the two metal plate transfer devices 2 are the first metal plate transfer device 2A and the second metal plate transfer device 2B. In the following, the porous sheet 10, non-magnetic plate 20, magnetic adsorption part 30, and lifting part 40 of the first metal plate transfer device 2A will be referred to as the first porous sheet 10A, the first non-magnetic plate 20A, the first magnetic adsorption part 30A, and the first lifting part 40A. The contact surface 10S of the first porous sheet 10A will be referred to as the first contact surface 10SA. The support surface 20S of the first non-magnetic plate 20A will be referred to as the first support surface 20SA. The porous sheet 10, non-magnetic plate 20, magnetic adsorption part 30, and lifting part 40 of the second metal plate transfer device 2B will be referred to as the second porous sheet 10B, the second non-magnetic plate 20B, the second magnetic adsorption part 30B, and the second lifting part 40B. The contact surface 10S of the second porous sheet 10B is designated as the second contact surface 10SB. The support surface 20S of the second nonmagnetic plate 20B is designated as the second support surface 20SB.

[0079] The first metal plate transfer device 2A holds the metal mask M by suction. The metal mask M comprises a first surface MS1 and a second surface MS2. The first surface MS1 and the second surface MS2 are two surfaces facing in opposite directions. The metal mask M is placed on the stage S, for example, with the second surface MS2 in contact with the stage S, and then, by a procedure similar to that of the first embodiment, the first metal plate transfer device 2A holds the metal mask M by suction with the first surface MS1 in contact with the first contact surface 10SA. That is, the first metal plate transfer device 2A brings the first contact surface 10SA into contact with the first surface MS1 of the metal mask M with the first magnetic adsorption part 30A in a non-adsorption position, and then moves the first magnetic adsorption part 30A to the adsorption position. As a result, the magnetic force of the first magnetic adsorption part 30A acts on the metal mask M, causing the metal mask M to be adsorbed and held by the first metal plate transfer device 2A with the first surface MS1 in contact with the first contact surface 10SA. Alternatively, the first contact surface 10SA may be brought into contact with the metal mask M while the first magnetic adsorption part 30A is in the adsorption position.

[0080] From this state, the second metal plate transfer device 2B is positioned so that the second contact surface 10SB of the second porous sheet 10B provided by the second metal plate transfer device 2B faces the second surface MS2 of the metal mask M. At this time, the second magnetic adsorption part 30B of the second metal plate transfer device 2B is in a non-adsorption position. Then, as shown by the arrow in Figure 11, the second metal plate transfer device 2B is moved so that the second contact surface 10SB comes into contact with the second surface MS2 of the metal mask M. Alternatively, instead of moving the second metal plate transfer device 2B, the second contact surface 10SB and the second surface MS2 of the metal mask M may be brought into contact by moving the first metal plate transfer device 2A that has the metal mask M adsorbed.

[0081] As shown in Figure 12, next, in the second metal plate transfer device 2B, the second lifting unit 40B moves the second magnetic adsorption unit 30B, which is in the non-adsorption position, to the adsorption position. As a result, the magnetic force of the second magnetic adsorption unit 30B acts on the metal mask M, attracting the second surface MS2 of the metal mask M to the second contact surface 10SB. Then, in the first metal plate transfer device 2A, the first lifting unit 40A moves the first magnetic adsorption unit 30A relative to the first non-magnetic plate 20A so as to increase the distance between the first non-magnetic plate 20A and the first magnetic adsorption unit 30A. That is, in the first metal plate transfer device 2A, the first magnetic adsorption unit 30A, which is in the adsorption position, is moved to the non-adsorption position. As a result, the magnetic adsorption of the first magnetic adsorption unit 30A to the metal mask M is released. In addition, in the first metal plate transfer device 2A, the first magnetic adsorption unit 30A, which is located in the adsorption position, may be moved to the non-adsorption position, and then in the second metal plate transfer device 2B, the second magnetic adsorption unit 30B, which is located in the non-adsorption position, may be moved to the adsorption position.

[0082] As shown in Figure 13, the first metal plate transfer device 2A, with its magnetic adsorption to the metal mask M released, is moved to separate the first surface MS1 of the metal mask M from the first contact surface 10SA. Alternatively, instead of moving the first metal plate transfer device 2A, the first surface MS1 of the metal mask M may be separated from the first contact surface 10SA by moving the second metal plate transfer device 2B, which is still adsorbing the metal mask M. After that, the second metal plate transfer device 2B, which is still adsorbing the metal mask M, is inverted.

[0083] Through the above procedure, the state changes from one where the first surface MS1 of the metal mask M is attracted to the first contact surface 10SA by the first magnetic adsorption part 30A, to a state where the second surface MS2 of the metal mask M is attracted to the second contact surface 10SB by the second magnetic adsorption part 30B. Therefore, the surface of the metal mask M that is adsorbed by the metal plate transfer device 2 can be reversed. The reversed metal mask M is then moved while being adsorbed by, for example, the second metal plate transfer device 2B, and then placed in any desired location when the second metal plate transfer device 2B releases the magnetic adsorption.

[0084] [Effects of the third embodiment] (3-1) By transferring the metal mask M, which is held by the first metal plate transfer device 2A, to the second metal plate transfer device 2B, the side of the metal mask M that is held by the metal plate transfer device 2 can be reversed. With such a front-to-back reversal operation, the orientation of the metal mask M is kept constant during the reversal operation, so deformation of the metal mask M associated with the front-to-back reversal operation can be suppressed. The effects of (1-1) to (1-7) and (2-1) described above can also be obtained in the metal mask transfer method of the third embodiment.

[0085] [Example of modification of the third embodiment] Furthermore, the third embodiment described above can be implemented with the following modifications. • Although the method of reversing the front and back sides of the metal mask M using two metal plate transfer devices 2 in the second embodiment has been illustrated, the same method can be applied when using the metal plate transfer device 1 in the first embodiment. Alternatively, the metal plate transfer device 1 in the first embodiment may be used instead of one of the two metal plate transfer devices 2. Furthermore, the two metal plate transfer devices 2 do not need to have the same configuration; for example, the above-mentioned modifications may be applied to only one of the metal plate transfer devices 2, or different modifications may be applied to each of the two metal plate transfer devices 2.

[0086] The two metal plate transfer devices 2 may be moved by being carried by an operator. At least one of the two metal plate transfer devices 2 may be connected to a moving mechanism such as a robotic arm or electric slider that moves the metal plate transfer devices 2 electrically. Alternatively, the two metal plate transfer devices 2 may be integrated together via a moving mechanism. For example, in a metal plate transfer system comprising multiple metal plate transfer devices 2 and multiple moving mechanisms, the first metal plate transfer device 2A may be connected to one moving mechanism, and the second metal plate transfer device 2B may be connected to another moving mechanism.

[0087] [Examples] Examples 1 to 3 and Comparative Examples 1 to 5 of the metal plate transfer device are described below. Note that each example is merely an example of the above embodiment and does not limit the embodiments, and each comparative example is a specific example that serves as a reference for explaining the effects of the example.

[0088] [Example 1] In Example 1, a transfer device having the same configuration as the metal plate transfer device 1 of the first embodiment was used to transfer the metal mask M, which was placed on the stage S, to another location using the same procedure as in the first embodiment.

[0089] [Example 2] In Example 2, a metal mask M placed on the stage S was transferred to another location using a transfer device having the same configuration as the metal plate transfer device 2 of the second embodiment, following the same procedure as in the first embodiment. The transfer device used in Example 2 has the same configuration as the transfer device used in Example 1, except that the non-magnetic plate 20 is equipped with ventilation holes 20H.

[0090] [Example 3] In Example 3, two transfer devices having the same configuration as the metal plate transfer device 2 of the second embodiment were used. Then, following the same procedure as in the third embodiment, the metal mask M placed on the stage S was adsorbed by one of the transfer devices, and then transferred to the other transfer device, thereby reversing the front and back sides of the metal mask M and transferring it to another location.

[0091] [Comparative Example 1] As shown in Figure 14, Comparative Example 1 used a metal plate transfer device 100 having the same configuration as the metal plate transfer device 1 of the first embodiment, except that it did not have a porous sheet 10. Then, the metal mask M placed on the stage S was transferred to another location using the same procedure as in the first embodiment. At this time, the metal mask M was supported by suction on the metal plate transfer device 100 while in contact with the support surface 20S.

[0092] [Comparative Example 2] As shown in Figure 15, Comparative Example 2 used a metal plate transfer device 101 having the same configuration as the metal plate transfer device 2 of the second embodiment, except that it did not have a porous sheet 10. Then, the metal mask M placed on the stage S was transferred to another location using the same procedure as in the first embodiment. At this time, the metal mask M was supported by suction on the metal plate transfer device 101 while in contact with the support surface 20S.

[0093] [Comparative Example 3] As shown in Figure 16, Comparative Example 3 used a metal plate transfer device 102 having the same configuration as the metal plate transfer device 1 of the first embodiment, except that a cushion 110 was provided instead of the porous sheet 10. The cushion 110 was made of a rubber sheet material mainly composed of acrylonitrile butadiene rubber (NBR). The cushion 110 has a contact surface 110S that comes into contact with the metal mask M. The metal mask M, which was placed on the stage S, was then transferred to another location using the same procedure as in the first embodiment. At this time, the metal mask M was supported by suction on the metal plate transfer device 102 while in contact with the contact surface 110S.

[0094] [Comparative Example 4] As shown in Figure 17, in Comparative Example 4, a metal plate transfer device 103 equipped with a plurality of vacuum suction pads 120, a tensioning mechanism 130, and a pad position adjustment mechanism 140 was used to transfer a metal mask M placed on a stage S to another location. The vacuum suction pads 120 are connected to, for example, a vacuum pump (not shown). The plurality of vacuum suction pads 120 hold both ends of the metal mask M in the longitudinal direction by vacuum suction. The plurality of vacuum suction pads 120 include a first vacuum suction pad 121 that holds one end of the metal mask M in the longitudinal direction by vacuum suction, and a second vacuum suction pad 122 that holds the other end of the metal mask M in the longitudinal direction by vacuum suction.

[0095] The tension-applying mechanism 130 applies tension to the metal mask M by increasing the distance between the first vacuum suction pad 121 and the second vacuum suction pad 122 while the multiple vacuum suction pads 120 are holding both ends of the metal mask M in the longitudinal direction. The tension-applying mechanism 130 moves at least one of the first vacuum suction pad 121 and the second vacuum suction pad 122 so that the distance between them increases. By applying tension to the metal mask M, the longitudinal central part of the metal mask M held by the multiple vacuum suction pads 120 is prevented from sagging. The pad position adjustment mechanism 140 is configured to change the relative position of the first vacuum suction pad 121 and the second vacuum suction pad 122 in the metal plate transfer device 103 according to the size of the metal mask M.

[0096] In Comparative Example 4, the method for transferring the metal mask M using the metal plate transfer device 103 involves first adjusting the relative positions of the first vacuum suction pad 121 and the second vacuum suction pad 122 according to the size of the metal mask M using the pad position adjustment mechanism 140. Then, the first vacuum suction pad 121 and the second vacuum suction pad 122 are brought into contact with the metal mask M, and the metal mask M is vacuum-suctioned by the first vacuum suction pad 121 and the second vacuum suction pad 122. Next, tension is applied to the metal mask M using the tension application mechanism 130 to prevent it from becoming loose. In this state, the metal plate transfer device 103 is moved, and then the vacuum suction by the first vacuum suction pad 121 and the second vacuum suction pad 122 is released at another transfer location. The metal mask M was transferred using the metal plate transfer device 103 by following these steps.

[0097] [Comparative Example 5] As shown in Figure 18, in Comparative Example 5, two metal plate transfer devices 103 were used. One transfer device adsorbed the metal mask M placed on the stage S, and then transferred it to the other transfer device, thereby reversing the front and back sides of the metal mask M and transferring it to another location.

[0098] The inversion operation of the metal mask M begins by using the first metal plate transfer device 103A, one of the two metal plate transfer devices 103, to adsorb the first surface MS1 of the metal mask M in the same procedure as in Comparative Example 4. From this state, the vacuum suction pad 120 of the second metal plate transfer device 103B, the other of the two metal plate transfer devices 103, is brought into contact with the second surface MS2 of the metal mask M. Then, the vacuum suction pad 120 of the second metal plate transfer device 103B adsorbs the second surface MS2 of the metal mask M. Furthermore, the suction holding of the metal mask M by the first metal plate transfer device 103A is released. After that, the second metal plate transfer device 103B is moved, and then the vacuum suction by the vacuum suction pad 120 of the second metal plate transfer device 103B is released at another transfer location. Following the above procedure, the metal mask M was transferred using two metal plate transfer devices 103, while simultaneously performing a front-to-back reversal operation of the metal mask M.

[0099] [evaluation] In Examples 1-3 and Comparative Examples 1-5, the presence or absence of deformation of the metal mask M after transfer was visually confirmed. In Examples 1-3, no deformation of the metal mask M was observed during transfer. In contrast, deformation of the metal mask M was observed during transfer in Comparative Examples 1-5. The mechanism of the deformation of the metal mask M that occurred in Comparative Examples 1-5 will be explained below.

[0100] In Comparative Example 1, since the metal plate transfer device 100 does not have a porous sheet 10, the metal mask M is magnetically attracted to the support surface 20S of the non-magnetic plate 20 in contact with it. At this time, because the metal mask M and the support surface 20S are in close contact, a sealed space is easily formed between the metal mask M and the support surface 20S when the metal mask M is peeled off from the support surface 20S. If magnetic attraction is released in this state and the metal mask M is peeled off from the support surface 20S, deformation occurs because a part of the metal mask M is lifted without being peeled off from the support surface 20S. Furthermore, compared to the case in which a porous sheet 10 is provided, if foreign matter is interposed between the metal mask M and the support surface 20S, the metal mask M is more likely to deform due to the unevenness caused by the foreign matter.

[0101] In Comparative Example 2, although the metal plate transfer device 101 does not have a porous sheet 10, the non-magnetic plate 20 has ventilation holes 20H, making it easier for the metal mask M to detach from the support surface 20S than in Comparative Example 1. However, the portion of the metal mask M that is positioned to block the ventilation holes 20H is not in contact with the support surface 20S of the non-magnetic plate 20, so deformation occurs in which it bends inward toward the ventilation holes 20H due to the magnetic force of the magnetic adsorption portion 30. Also, similar to Comparative Example 1, compared to the case with a porous sheet 10, if foreign matter is interposed between the metal mask M and the support surface 20S, the metal mask M is more prone to deformation due to the unevenness caused by the foreign matter.

[0102] In Comparative Example 3, even when foreign matter is interposed between the metal mask M and the support surface 20S, the cushion 110 absorbs the irregularities caused by the foreign matter, thereby suppressing deformation of the metal mask M. However, in Comparative Example 3, as in Comparative Example 1, the metal mask M and the contact surface 110S are in close contact, so when peeling the metal mask M from the contact surface 110S, a sealed space is easily formed between the metal mask M and the contact surface 110S. If magnetic adsorption is released in this state and the metal mask M is peeled from the contact surface 110S, deformation occurs because a part of the metal mask M is lifted without being peeled from the contact surface 110S.

[0103] In Comparative Examples 4 and 5, the metal mask M is held by vacuum suction using the vacuum suction pad 120. Therefore, while the configurations of Examples 1 to 3 allow the magnetic force required to hold the weight of the metal mask M to be distributed across the entire metal mask M, in Comparative Examples 4 and 5, localized forces act on the metal mask M. Consequently, deformation occurs in the portion of the metal mask M that is held in place by the vacuum suction pad 120. In addition, since both ends of the metal mask M in the longitudinal direction are held in place by vacuum suction, the central part of the metal mask M in the longitudinal direction becomes more susceptible to deformation due to its own weight. Therefore, it is necessary to apply tension using the tension-applying mechanism 130, but this leads to an increase in the size and complexity of the device. Depending on the shape of the through-holes MH in the metal mask M, it may be difficult for the tension applied by the tension-applying mechanism 130 to act locally, and even with the tension-applying mechanism 130, the aforementioned deflection of the metal mask M may still occur.

[0104] Furthermore, in the case of vacuum suction using the vacuum suction pad 120, it is necessary to suction both ends of the metal mask M to prevent the edges of the metal mask M from becoming loose. Therefore, it is necessary to change the position of the vacuum suction pad 120 according to the size of the metal mask M using the pad position adjustment mechanism 140, but this leads to an increase in the size and complexity of the device.

[0105] Based on the above, the configurations of Examples 1 to 3 can suppress deformation of the metal mask M that occurs in Comparative Examples 1 to 5. Furthermore, the configurations of Examples 1 to 3 can suppress deformation of the metal mask M without the need for the tension-applying mechanism 130, compared to the configurations of Comparative Examples 4 and 5, thus allowing for a smaller device. Moreover, the configurations of Examples 1 to 3 can transfer any metal mask M smaller than the porous sheet 10, regardless of its size, without the need for the pad position adjustment mechanism 140, thus allowing for a smaller device. [Explanation of Symbols]

[0106] M... Metal Mask MH…Through hole MF1…first magnetic force MF2...Second magnetic field MS1...Page 1 MS2...Page 2 S... Stage 1,2...Metal plate transfer device 2A…First metal plate transfer device 2B…Second metal plate transfer device 10…Porous sheet 10S…Contact surface 11…Opening 20...Nonmagnetic plate 20H... Ventilation holes 20S…support surface 30…Magnetic adsorption part 31…Permanent magnet sheet 32...Support plate 40... Lifting section

Claims

1. A metal plate transfer device for transferring sheet-shaped metal plates that are attracted to magnets, A porous sheet having a contact surface that is in contact with the metal plate, A non-magnetic plate having a support surface that supports the surface of the porous sheet opposite to the contact surface, A magnetic adsorption unit that applies a magnetic force to the metal plate from the side opposite to the side where the porous sheet is located relative to the non-magnetic plate, It comprises a lifting mechanism that changes the distance between the non-magnetic plate and the magnetic adsorption part, The hardness of the contact surface is lower than the hardness of the support surface. Metal plate transfer device.

2. The porous sheet has open-cell pores and a porosity of 60% or more. The metal plate transfer device according to claim 1.

3. The non-magnetic plate is provided with ventilation holes extending from the support surface. The metal plate transfer device according to claim 2.

4. The contact surface has an Asker C hardness of 20 or less. The metal plate transfer device according to claim 1.

5. The lifting mechanism changes the distance between the non-magnetic plate and the magnetic adsorption part by moving the magnetic adsorption part relative to the non-magnetic plate. The position of the magnetic adsorption part when the metal plate is adsorbed to the contact surface by the magnetic force of the magnetic adsorption part is the adsorption position. When the metal plate is not attracted to the contact surface by the magnetic force of the magnetic adsorption part, the position of the magnetic adsorption part is the non-adsorption position. When the lifting mechanism moves the magnetic adsorption part from the adsorption position to the non-adsorption position, the amount of movement of the magnetic adsorption part is 2 mm or more. The metal plate transfer device according to claim 1.

6. The magnetic adsorption portion alternately applies a first magnetic force and a second magnetic force weaker than the first magnetic force in a one-dimensional direction along the contact surface. The metal plate transfer device according to claim 1.

7. The porous sheet has openings that penetrate in the thickness direction, When the metal plate and the porous sheet are brought into contact, the through holes in the metal plate are located inside the opening in the planar direction of the metal plate. The metal plate transfer device according to claim 1.

8. A sheet-like metal plate that is attracted to a magnet is brought into contact with a contact surface of a porous sheet, which is supported by a support surface of a non-magnetic plate, that is opposite to the surface in contact with the non-magnetic plate and has a lower hardness than the support surface. The magnetic force of the magnetic adsorption part that attracts the metal plate to the contact surface is applied to the metal plate from the side opposite to the side where the porous sheet is located relative to the non-magnetic plate, This includes changing the distance between the non-magnetic plate and the magnetic adsorption part. Metal plate transfer method.

9. The first surface of a sheet-like metal plate that is attracted to a magnet is brought into contact with a first contact surface of a first porous sheet, which is supported by a first support surface of the first non-magnetic plate, and which is opposite to the surface in contact with the first non-magnetic plate and has a lower hardness than the first support surface. The magnetic force of the first magnetic adsorption part that attracts the metal plate to the first contact surface is applied to the metal plate from the side opposite to the side where the first porous sheet is located relative to the first non-magnetic plate, In a state in which the first surface is in contact with the first porous sheet, the second contact surface of the metal plate, which is opposite to the surface in contact with the second nonmagnetic plate and has a lower hardness than the second support surface, is brought into contact with the second contact surface of the second porous sheet, which is supported by the second support surface of the second nonmagnetic plate. The magnetic force of the second magnetic adsorption part that attracts the metal plate to the second contact surface is applied to the metal plate from the side opposite to the side where the second porous sheet is located relative to the second non-magnetic plate, This includes increasing the distance between the first non-magnetic plate and the first magnetic adsorption portion. Metal plate transfer method.

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