A mask plate, a mask plate net-stretching device and a net-stretching method

Abstract

The present invention discloses a mask plate, a mask plate net stretching device and a net stretching method. The mask plate net stretching device comprises a support platform and a support magnet. The support platform comprises a support frame and a support opening. The support magnet is arranged on the support frame. The support magnet can interact with a positioning magnet on the mask plate to make the mask plate float above the support opening. In the above manner, the present invention can improve the net stretching accuracy of the mask plate.

Description

Technical Field

[0001] The present invention relates to the field of optoelectronic display technology, and in particular to a mask plate, a mask plate meshing device and a meshing method. Background Art

[0002] Masks are widely used in photolithography, evaporation and other process fields due to their precise positioning performance of functional graphics. For example, they can be used for the evaporation of luminescent materials of organic light-emitting diode (OLED) display panels. With the improvement of the display effect requirements, the higher the resolution of the display panel, the higher the precision requirements of the evaporation mask. For example, a fine metal mask (FMM) can be used. Before using the FMM, the mask sheet needs to be welded to the mask frame. However, the fine metal mask is prone to uneven tension when stretching the net, resulting in different degrees of deviation of the mask opening on the mask net after stretching the net, which makes the pixel position accuracy (PPA) of the produced pixels low, and is prone to color cast, color mixing and other problems. Summary of the invention

[0003] The main technical problem solved by the present invention is to provide a mask plate, a mask plate meshing device and a meshing method, which can improve the meshing accuracy of the mask plate.

[0004] In order to solve the above technical problems, a technical solution adopted by the present invention is: to provide a mask plate net stretching device, the mask plate net stretching device includes a supporting platform and a supporting magnet, the supporting platform includes a supporting frame and a supporting opening; the supporting magnet is arranged on the supporting frame, and the supporting magnet can interact with the positioning magnet on the mask plate to make the mask plate float above the supporting opening.

[0005] In one embodiment, there are multiple groups of supporting magnets, each group of supporting magnets includes a first supporting magnet, a second supporting magnet and a third supporting magnet. The first supporting magnet is used to interact with the positioning magnet to apply a force perpendicular to the direction of the supporting platform to the mask plate, and the second supporting magnet and the third supporting magnet are used to interact with the positioning magnet to apply a force parallel to the direction of the supporting platform to the mask plate.

[0006] In one embodiment, the plurality of groups of support magnets are evenly distributed around the support opening.

[0007] In one embodiment, the support frame has a first surface and a second surface relative to each other, the first surface is used to support the mask plate, and a plurality of storage grooves are provided on the first surface, and a plurality of groups of support magnets are respectively accommodated in the plurality of storage grooves; a driving member is provided in the storage groove to drive the support magnet to move in the storage groove.

[0008] In one embodiment, the supporting magnet is an electromagnet, and the mask stretching device further includes a magnetic control unit, which is used to adjust the magnetism and / or magnetic force of the supporting magnet.

[0009] In one embodiment, the mask plate stretching device further includes a distance sensor, which is disposed on the surface of the supporting magnet and is used to detect the distance between the supporting magnet and the mask plate.

[0010] In order to solve the above technical problems, another technical solution adopted by the present invention is: providing a mask plate, the mask plate includes a mask frame and a positioning magnet, the mask frame has an opening area; the positioning magnet is arranged on the mask frame, and the positioning magnet can interact with the supporting magnet on the net stretching device to make the mask plate float above the supporting platform of the net stretching device.

[0011] In one embodiment, there are multiple groups of positioning magnets, each group of positioning magnets includes a first positioning magnet, a second positioning magnet and a third positioning magnet, the first positioning magnet is used to interact with the supporting magnet to apply a force perpendicular to the direction of the supporting platform to the mask plate, and the second positioning magnet and the third positioning magnet are used to interact with the supporting magnet to apply a force parallel to the direction of the supporting platform to the mask plate.

[0012] In one embodiment, the mask frame includes a first surface and a second surface that are arranged opposite to each other, the first surface is used to place the mask net, and the second surface is the side of the mask frame facing the supporting platform. The second surface is provided with multiple positioning grooves, and multiple groups of positioning magnets are respectively arranged in the multiple positioning grooves.

[0013] In order to solve the above technical problems, another technical solution adopted by the present invention is: to provide a mask plate stretching method, the mask plate stretching method includes placing a mask plate with a positioning magnet on a supporting platform with a supporting magnet; regulating the force between the positioning magnet and the supporting magnet to make the mask plate float on the supporting platform; adjusting the force between the positioning magnet and the supporting magnet to align the mask plate with the supporting opening of the supporting platform; applying a stretching resistance force to the mask plate; regulating the force between the positioning magnet and the supporting magnet to make the mask plate remain stationary on the supporting platform; providing a mask net and fixing the mask net on the mask plate.

[0014] The beneficial effect of the present invention is that, different from the prior art, in the scheme of the present invention, by respectively setting magnets on the support platform and the mask frame, the interaction between the support magnets and the positioning magnets can be used to make the mask plate suspended above the support platform. By suspending the mask plate above the support platform, the friction between the mask frame and the support platform can be eliminated, so as to prevent the mask frame from being deformed when adjusting the alignment relationship between the mask frame and the support platform, and to be more accurate when applying the net stretching resistance force to the mask frame, thereby improving the net stretching accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a schematic structural diagram of a mask plate in an embodiment of the present application;

[0016] Figure 2 It is a structural schematic diagram of the support platform of the net-stretching device in the embodiment of the present application;

[0017] Figure 3 is a schematic diagram of the assembly structure of the mask plate and the support platform in an embodiment of the present application;

[0018] Figure 4 is a schematic cross-sectional structure diagram of a support control system in an embodiment of the present application;

[0019] Figure 5 is a side view of a mask plate in an embodiment of the present application;

[0020] Figure 6 is a schematic cross-sectional structure diagram of a support control system in an embodiment of the present application;

[0021] Figure 7 It is a side view of the support platform in the embodiment of the present application. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solution and effect of the present application clearer and more specific, the present application is further described in detail below with reference to the accompanying drawings and examples.

[0023] See also Figure 1 , Figure 1 1 is a schematic diagram of the structure of the mask plate in the embodiment of the present application. In this embodiment, the mask plate 10 includes a mask frame 11 and a mask net 12, and the mask net 12 has a mask opening 13, which can be used to evaporate the light-emitting material to make pixels. The mask net 12 is installed on the mask frame 11, and the mask frame 11 plays a role in supporting the mask net 12. The mask plate 10 can be a fine metal mask plate (FMM), and correspondingly, the mask net 12 can be a strip mask net (FMM sheet) of the fine metal mask plate.

[0024] Specifically, the mask net 12 is generally stretched by a stretching device and then welded to the mask frame 11. After the stretched mask net 12 is welded to the mask frame 11, the mask net 12 will apply a tensile force (SF) to the mask frame 11, causing the mask frame 11 to deform, which will further cause the mask net 12 to sag and deform, resulting in an inaccurate position of the mask opening 13. Therefore, during the stretching process of the mask plate, a counter force (CF) needs to be applied to the mask frame to cause the mask frame to deform in advance and generate a prestress, which has a tendency to recover to an undeformed state, and is used to offset the tensile force of the mask net after welding.

[0025] Please refer to Figure 2 and Figure 3 , Figure 2 This is a schematic diagram of the structure of the support platform of the net-stretching device in the embodiment of the present application. Figure 3 It is a schematic diagram of the assembly structure of the mask plate and the support platform in the embodiment of the present application. In this embodiment, the support platform 20 includes a support frame 21 and a support opening 22. The support frame 21 is used to support the mask frame 11. The support opening 22 corresponds to the opening area of ​​the mask frame 11, that is, the mask area of ​​the mask plate. During the net stretching process, it is generally necessary to place the mask frame 11 on the support platform 20 of the net stretching device, apply a resistance force (CF) to the mask frame 11, and then stretch the mask net 12 and weld it to the mask frame 11.

[0026] Among them, when placing the mask frame 11, it is necessary to align the mask frame 11 with the support platform 20 so that the mask frame 11 corresponds to the support frame 21 to play a supporting role; the opening area of ​​the mask frame 11 corresponds to the support opening 22 to facilitate the stretching of the mask net 12. The alignment accuracy of the mask frame 11 and the support frame 21 should be controlled so that the mask opening 13 on the mask net 12 can be more accurate during the subsequent stretching. During the alignment process, it is necessary to apply force to different positions of the mask frame 11 to adjust the position of the mask frame 11 to achieve the alignment effect. However, due to the presence of a certain friction between the mask frame 11 and the support platform 20, the mask frame 11 is easily deformed when the mask frame 11 is positioned, which affects the stretching accuracy. Furthermore, the friction between the mask frame 11 and the support platform 20 will also cause the resistance force (CF) applied to the mask frame 11 during the stretching process to be unable to balance the force according to the design value, so that the mask opening 13 on the mask net 12 cannot be fixed according to the design position, thereby further reducing the PPA of the mask opening 13 on the mask net 12.

[0027] Based on this, the present application provides a mask plate and a net stretching device, which cooperate with each other to allow the mask frame 11 to float above the support platform 20, thereby reducing the influence of the friction between the mask frame 11 and the support platform 20 on the net stretching accuracy.

[0028] Please continue reading Figure 3 The present application provides a support control system 30, which includes a support magnet arranged on a support platform 20 and a positioning magnet arranged on a mask plate. By controlling the magnetism and magnetic force of the support magnet and / or the positioning magnet, the repulsive magnetic force between the magnets is utilized to make the mask frame 11 float above the support platform 20.

[0029] See also Figure 4 , Figure 4 It is a schematic diagram of the cross-sectional structure of the support control system in the embodiment of the present application. In this embodiment, the support magnet 31 of the support control system 30 is arranged on the support frame 21 of the support platform 20, and the positioning magnet 32 ​​of the support control system 30 is arranged on the mask frame 11 of the mask plate. The positioning magnet 32 ​​is at least arranged on the side of the mask frame 11 facing the support platform 20, and correspondingly, the support magnet 31 is at least arranged on the side of the support frame 21 facing the mask frame 11, and the setting positions of the support magnet 31 and the positioning magnet 32 ​​correspond to each other, so that when the mask frame 11 is aligned with the support platform 21, the support magnet 31 and the positioning magnet 32 ​​can interact with each other to generate magnetic force.

[0030] In one embodiment, the positioning magnet 32 ​​is a permanent magnet that retains a certain magnetic property for a long time and has an N pole and an S pole with fixed polarity. The supporting magnet 31 is an electromagnet. The magnetic strength and polarity of the supporting magnet 31 can be adjusted by controlling the magnitude and direction of the current, so as to adjust the magnitude and direction of the magnetic force between the supporting magnet 31 and the positioning magnet 32. Figure 4 As shown, the positioning magnet 32 ​​faces the N pole outward, so it is necessary to adjust the magnetism of the supporting magnet 31 to the N pole, so as to generate a repulsive magnetic force between the supporting magnet 31 and the positioning magnet 32, and suspend the mask frame 11 above the supporting platform 20. In other embodiments, the supporting magnet 31 may be a permanent magnet, and the positioning magnet 32 ​​may be an electromagnet. Alternatively, both the supporting magnet 31 and the positioning magnet 32 ​​may be electromagnets, which is not limited here, as long as the magnetic force and magnetic regulation can be achieved.

[0031] Furthermore, the support control system 30 includes a magnetic control unit 33, which is electrically connected to the support magnet 31 to control the magnitude and direction of the current flowing through the support magnet 31. The magnetic control unit 33 can be disposed on the support platform 20 or can be independent of the support platform 20, and the location of the magnetic control unit 33 is not limited herein.

[0032] Please refer to Figure 4 and Figure 5 , Figure 5 It is a side view of the mask plate in the embodiment of the present application. In one embodiment, the mask frame 11 includes a first surface 101 and a second surface 102 arranged opposite to each other, the first surface 101 is used to place the mask net 12, the second surface 102 is the surface of the mask frame 11 facing the support platform 20, and the second surface 102 is provided with at least one positioning groove 111, and the positioning magnet 32 ​​is arranged in the positioning groove 111. The positioning groove 111 can be used to accommodate the positioning magnet 32 ​​on the one hand, and can also reduce the weight of the mask frame 11 on the other hand, so as to reduce the weight, so that the mask frame 11 is easier to suspend.

[0033] In one embodiment, the positioning magnet 32 ​​is disposed on the top wall of the positioning groove 111 and can interact with the supporting magnet 31 to generate a force perpendicular to the supporting platform 20 to regulate the mask frame 11 to move in a direction (Z direction) perpendicular to the supporting platform 20 .

[0034] See also Figure 6 , Figure 6 In one embodiment, the positioning magnet 32 ​​can also be disposed on the side wall of the positioning groove 111, and can interact with the supporting magnet 31 to generate a force parallel to the supporting platform 20, thereby regulating the mask frame 11 to move in a direction (X, Y direction) parallel to the supporting platform 20.

[0035] By providing positioning magnets 32 on the top wall and side walls of the positioning groove 111, the position of the mask frame 11 can be adjusted in the vertical and horizontal directions (X, Y, Z directions), thereby achieving alignment between the mask frame 11 and the support frame 21. When a plurality of positioning magnets 32 are provided in the positioning groove 111, the magnetic poles of each positioning magnet 32 ​​facing outward are the same. In other embodiments, the magnetic poles of each positioning magnet 32 ​​facing outward may also be partially the same.

[0036] The positioning magnet 32 ​​may be adhered to the groove wall of the positioning groove 111 by adhesive, so that the positioning magnet 32 ​​is fixed to the mask frame 11. Alternatively, an iron / magnetic adsorption member may be provided on the groove wall of the positioning groove 111, and the positioning magnet 32 ​​may be adsorbed and fixed to the mask frame 11 by utilizing the adsorption force of the positioning magnet 32 ​​on the iron / magnetic adsorption member.

[0037] Please continue reading Figure 3, there are multiple support control systems 30, and there are multiple corresponding positioning magnets 32. The multiple positioning magnets 32 can be divided into multiple groups, and the multiple groups of positioning magnets 32 are respectively arranged in multiple positioning grooves 111, that is, the positioning magnets 32 arranged in the same positioning groove 111 are divided into one group. Among them, the mask frame 11 includes a first side 13 and a second side 14 with relatively short lengths, and the positioning grooves 111 are preferably arranged on the first side 13 and the second side 14. This is because the shorter side has a smaller deformation amount when the same external force is applied to the longer side. The setting of the positioning grooves 111 will affect the strength of the mask frame 11 to a certain extent. By setting the positioning grooves 111 on the shorter first side 13 and the second side 14, it is ensured that when a preset force is applied to the mask frame 11, the mask frame 11 can have a smaller deformation amount. Furthermore, by setting the positioning grooves 111 on two parallel sides, the deformation distribution of the entire mask frame 11 is relatively uniform, and it is avoided that the positioning grooves are set on a certain side so that the stress is concentrated on the side, resulting in a large deformation of the side, which affects the fixing accuracy of the mask plate. More preferably, the number of positioning grooves 111 on the first side 13 and the second side 14 is the same, so as to avoid that when the number of positioning grooves 111 on the first side 13 and the second side 14 differs too much, the structural strength of the first side 13 and the second side 14 differs too much, resulting in the side with a large number of positioning grooves 111 being prone to large deformation. Furthermore, by setting the number of positioning grooves 111 on the first side 13 and the second side 14 to be the same, it is also conducive to more precise adjustment of the position of the mask frame 11. In other embodiments, positioning grooves can also be set on the two sides of the mask frame 11 with relatively long lengths. Preferably, a plurality of positioning grooves 111 are evenly distributed along the periphery of the mask frame 11.

[0038] Please refer to Figure 4 and Figure 7 , Figure 7 In one embodiment, the support frame 21 includes a first surface 201 and a second surface 202 that are arranged opposite to each other, the first surface 201 is used to place the mask frame 11, the second surface 202 is fixed on the base, and the support magnet 31 is arranged on the first surface 201.

[0039] Among them, the supporting magnet 31 can be directly arranged on the first surface 201, that is, the supporting magnet 31 protrudes from the surface of the supporting frame 21 to correspond to the positioning groove 111 of the mask frame 11. In other embodiments, a receiving groove 211 can also be arranged on the first surface 201, and a driving member 212 can be arranged in the receiving groove 211. When the supporting magnet 31 is needed, the supporting magnet 31 is driven to extend out of the receiving groove 211 to interact with the positioning magnet 32, and when the supporting magnet 31 is not needed, the supporting magnet 31 is retracted into the receiving groove 211. By setting the receiving groove 211, the supporting magnet 31 can be protected from being damaged. If the supporting magnet 31 is always in a protruding state, it may be damaged by collision, especially during the handling and transportation of the supporting platform 20. On the other hand, it can prevent dust and prevent the supporting magnet 31 from being damaged by dust and humid air, resulting in a shortened life.

[0040] The positions and number of the supporting magnets 31 correspond to the positioning magnets 32. Specifically, the supporting magnets 31 are multiple groups, corresponding to each group of positioning magnets 32. When there are multiple groups of positioning magnets 32, the corresponding group of supporting magnets is also multiple. Figure 4 and Figure 6 shown.

[0041] Please continue reading Figure 6 , the support control system 30 includes a corresponding group of positioning magnets 32 and a group of supporting magnets 31. Each group of positioning magnets 32 includes a first positioning magnet 321, a second positioning magnet 322 and a third positioning magnet 323, the first positioning magnet 321 is arranged on the top wall of the positioning groove 111, and the second positioning magnet 322 and the third positioning magnet 323 are respectively arranged on the side walls of the receiving groove 111. Correspondingly, each group of supporting magnets 31 includes a first supporting magnet 311, a second supporting magnet 312 and a third supporting magnet 313, the first supporting magnet 311 is arranged in alignment with the first positioning magnet 321, and the second supporting magnet 312 and the third supporting magnet 313 are arranged in alignment with the second positioning magnet 322 and the third positioning magnet 323, respectively. The magnitude and direction of the magnetic force between the first positioning magnet 321 and the first supporting magnet 311, the second positioning magnet 322 and the second supporting magnet 312, and the third supporting magnet 313 and the third positioning magnet 323 can be individually regulated to finely adjust the position of the mask frame 11. Further, when there are multiple support control systems 30, the magnitude and direction of the magnetic force between the supporting magnets 31 and the positioning magnets 32 in each support control system 30 can be individually regulated to be able to regulate the position of the mask frame 11 as a whole, so that the force on each part of the mask frame 11 is uniform, and thus the second surface 102 of the mask frame 11 is on a horizontal plane.

[0042] When the mask plate needs to be stretched, a mask frame 11 provided with a positioning magnet 32 ​​is provided, and the mask frame 11 is placed on the support platform 20 so that the opening area of ​​the mask frame 11 corresponds to the support opening 22 of the support platform 20. The second support magnets 312 of the plurality of support control systems 30 are energized respectively to generate magnetism, and the polarity of the second support magnets 312 should be controlled to be opposite to the polarity of the corresponding second positioning magnet 322 to generate a repulsive force, and the mask frame 11 is suspended above the support platform 20 by using the force generated by the plurality of support control systems 30.

[0043] It is determined whether the distances from different positions of the second surface 102 of the mask frame 11 to the supporting platform 20 are the same, so as to determine whether the mask frame 11 is flat in the Z direction.

[0044] Specifically, the support control system 30 further includes a distance sensor 34, which can be disposed on the first surface 201 of the support platform 20. Furthermore, the distance sensor 34 can be disposed on the surface of the support magnet 31 facing the mask frame 11, so as to detect the distance between the mask frame 11 and the support platform 20. The distance sensor 34 can be a light detector, and the specific detector type is not limited, as long as it can realize distance detection.

[0045] If the distance at a certain position is too large, the current of the second supporting magnet 312 can be reduced to reduce the magnetic force between the second supporting magnet 312 and the corresponding second positioning magnet 322, so as to reduce the height of the mask frame 11 at that position. If the distance at a certain position is too small, the current of the second supporting magnet 312 can be increased to increase the magnetic force between the second supporting magnet 312 and the corresponding second positioning magnet 322, so as to increase the height of the mask frame 11 at that position, and then adjust the second surface 102 of the mask frame 11 to a horizontal plane. If necessary, the polarity of the supporting magnet 31 can also be adjusted, and the distance between the mask frame 11 and the supporting platform 20 can be adjusted by using the attraction between the supporting magnet 31 and the positioning magnet 32.

[0046] Furthermore, it is also necessary to determine whether the opening area of ​​the mask frame 11 is aligned with the support opening 22 in the X and Y directions. If the position is offset, the magnetic force and polarity of the second support magnet 312 and the third support magnet 313 can be adjusted to adjust the position of the mask frame 11 in the X and Y directions.

[0047] In this embodiment, when adjusting the position, the mask frame 11 is in a suspended state, there is no friction resistance, and the shape of the mask frame is not affected. After adjusting to the target position, the magnetic force of the supporting magnet 31 is controlled to slowly lower the mask frame 11 and return it to the supporting platform 20, that is, the mask frame 11 is placed on the supporting platform 20 to perform the net stretching work.

[0048] Specifically, after the position of the mask frame 11 is confirmed, the power supply of each supporting magnet 31 is removed to eliminate the force between the supporting magnet 31 and the positioning magnet 32, so that the mask frame 11 falls back onto the supporting platform 20. The power supply current of the supporting magnet 31 can be gradually reduced to gradually reduce the magnetic force, so that the mask frame 11 falls slowly.

[0049] When stretching the net, the second support magnets 312 of the plurality of support control systems 30 are energized to generate magnetism, and the mask frame 11 is suspended above the support platform 20, and a tensioning resistance force (CF) is applied to the mask frame 11. After the force is applied, the power supply current of the support magnets 31 is slowly reduced, so that the mask frame 11 slowly falls onto the support platform 20. The mask net 12 is stretched and fixed on the mask frame 11, and the stretching of a mask net is completed. When the next mask net is stretched, the mask frame 11 is suspended again, a tensioning resistance force (CF) is applied, and the mask frame 11 is placed back on the support platform to fix the mask net 12, and the cycle is repeated until all the mask nets are fixed.

[0050] In the above implementation, by designing a non-contact support control system and a magnetic control unit, the mask plate can be completely suspended during the stretching process to eliminate the influence of friction; at the same time, the deformation of the mask frame during the positioning process can be reduced, thereby improving the stretching accuracy, increasing the evaporation yield, and improving the product display effect.

[0051] Furthermore, the distance between the mask frame and the support platform is monitored by the distance measuring sensor and the non-contact control component, and the support effect of the non-contact support component is adjusted by changing the current size to ensure that the mask plate is in a suspended state, so that the mask frame is not affected by friction during the subsequent net stretching process, thereby improving the net stretching accuracy, improving the evaporation yield, and improving the product display effect. The distance measuring sensor and the magnetic control unit can monitor the suspension state of the mask frame and the relative position of the mask frame in real time, and control the size and direction of the current to control the size of the magnetic force and the polarity of the electromagnet, thereby adjusting the position of the mask frame, reducing the deformation of the mask frame during the whole positioning process, and improving the net stretching accuracy.

[0052] The above description is only an implementation method of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A mask plate stretching device, characterized in that: include: a support platform, including a support frame and a support opening; A supporting magnet is disposed on the supporting frame, and the supporting magnet can interact with the positioning magnet on the mask plate to make the mask plate float above the supporting opening; The support frame has a first surface and a second surface opposite to each other, the first surface is used to carry the mask plate, a plurality of receiving grooves are arranged on the first surface, and a plurality of groups of the support magnets are respectively received in the plurality of receiving grooves; A driving member is arranged in the receiving groove to drive the supporting magnet to move in the receiving groove.

2. The mask plate stretching device according to claim 1, characterized in that: The supporting magnets are multiple groups, each group of supporting magnets includes a first supporting magnet, a second supporting magnet and a third supporting magnet, the first supporting magnet is used to interact with the positioning magnet to apply a force perpendicular to the direction of the supporting platform to the mask plate, and the second supporting magnet and the third supporting magnet are used to interact with the positioning magnet to apply a force parallel to the direction of the supporting platform to the mask plate.

3. The mask plate stretching device according to claim 2, characterized in that: A plurality of groups of the supporting magnets are evenly distributed around the supporting opening.

4. The mask plate stretching device according to claim 2, characterized in that: When the supporting magnet is needed, the supporting magnet is driven to extend out of the receiving slot to interact with the positioning magnet. When the supporting magnet is not needed, the supporting magnet is retracted into the receiving slot.

5. The mask plate stretching device according to claim 1, characterized in that: The supporting magnet is an electromagnet, and the mask plate stretching device also includes a magnetic control unit, which is used to adjust the magnetism and / or magnetic force of the supporting magnet.

6. The mask plate stretching device according to claim 1, characterized in that: The mask plate stretching device also includes: The distance sensor is arranged on the surface of the supporting magnet and is used to detect the distance between the supporting magnet and the mask plate.

7. A method for stretching a mask plate, characterized in that: include: placing the mask plate with the positioning magnet on a supporting platform with the supporting magnet; Regulating the acting force between the positioning magnet and the supporting magnet so that the mask plate is suspended on the supporting platform; Adjusting the acting force between the positioning magnet and the supporting magnet so that the mask plate is aligned with the supporting opening of the supporting platform; Applying a tensioning resistance force to the mask plate; Regulating the acting force between the positioning magnet and the supporting magnet so that the mask plate is stationary on the supporting platform; Providing a mask net, and fixing the mask net on the mask plate; The supporting magnet is arranged on a supporting frame, the supporting frame has a first surface and a second surface opposite to each other, the first surface is used to carry the mask plate, a plurality of receiving grooves are arranged on the first surface, and a plurality of groups of the supporting magnets are respectively received in the plurality of receiving grooves; A driving member is provided in the receiving groove to drive the supporting magnet to move in the receiving groove; When the supporting magnet is needed, the supporting magnet is driven to extend out of the receiving slot to interact with the positioning magnet. When the supporting magnet is not needed, the supporting magnet is retracted into the receiving slot.

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