Electrostatic discharge apparatus and method for metal mask

Abstract

The application provides an electrostatic discharge device of a metal mask, which directly discharges the electric charge on the surface of a product through an electrostatic discharge assembly, thereby reducing the electrostatic adsorption component on the surface of the product. The electrostatic discharge assembly in the electrostatic discharge device can be in contact with the surface to be discharged with electrostatic in a bufferable manner, and can achieve buffering of a first buffer height, so that the position deviation is dynamically compensated while the electrostatic charge is discharged. The electrostatic discharge assembly is in contact with the surface to be discharged with electrostatic in a bufferable manner, so that hard collision and mechanical contact are avoided during the contact process, thereby avoiding scratching and contamination of the surface of the product, and further improving the yield of the product.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of precision machining equipment for semiconductor or display panel manufacturing, and in particular to an electrostatic discharge device and method for a metal mask. BACKGROUND

[0002] In the prior art, a laser processing station usually uses electrostatic adsorption to fix a product. Specifically, when the product is loaded onto a glass platform, a positive voltage of 150V-200V is applied to the platform to fix the product on the surface of the platform by using electrostatic adsorption force. This process has the following technical defects:

[0003] 1. In the electrostatic open state, the product is subjected to the downward electrostatic force, which causes the air between the product and the glass platform to be forced out, forming a local negative pressure environment. 2. Due to the charge induction effect, after the electrostatic is turned off, some electrostatic charges remain between the glass platform and the product, and at this time the negative pressure environment still exists. Experiments show that this negative pressure adsorption and electrostatic residual state needs 10-30 minutes to dissipate naturally. When unloading, under the combined action of the negative pressure adsorption force and the electrostatic residual adsorption force, the product and the platform will generate excessive adhesion, causing the product to be excessively adsorbed by the platform in the local area. At this time, if the product is forcibly unloaded, the adsorbed part of the product will be subjected to uneven pulling force, which is prone to plastic deformation or even structural damage, seriously affecting the yield of the product.

[0004] Especially for precision components such as ultra-thin flexible substrates, this problem is more prominent. The method of simply relying on prolonging the standing time to eliminate the adsorption force in the prior art not only greatly reduces the utilization rate of the equipment, but also cannot fundamentally solve the mechanical damage problem during unloading. Therefore, it is urgent to develop a technical solution that can effectively eliminate the residual adsorption force to solve this long-standing industry problem. SUMMARY

[0005] The purpose of the present application is to provide an electrostatic discharge device and method for a metal mask, which can effectively eliminate the residual adsorption force after electrostatic adsorption and fundamentally solve the mechanical damage problem of the product during unloading.

[0006] The present application provides an electrostatic discharge device for a metal mask, which is connected with a product taking and placing device, and the product taking and placing device comprises:

[0007] A driving assembly is used to realize the lifting of the product taking and placing device in the Z-axis direction;

[0008] A connecting assembly is fixedly connected with the driving assembly;

[0009] The electrostatic discharge device comprises:

[0010] The electrostatic discharge assembly is fixedly arranged on the connecting assembly and can be in contact with the surface to be discharged electrostatically in a buffering manner, and a first buffering height h1 can be achieved.

[0011] The electrostatic discharge assembly comprises:

[0012] The telescopic member has a fixed housing and a telescopic shaft which can be elongated or shortened along the Z axis in the fixed housing, and the telescopic member passes through the through hole of the connecting assembly;

[0013] The fixed member is used for fixedly arranging the telescopic member on the connecting assembly; and

[0014] The releasing member is fixedly arranged on the end of the telescopic shaft, and when the releasing member is in contact with the surface to be discharged electrostatically, the telescopic shaft is elongated or shortened along the Z axis in the fixed housing to buffer the contact force between the releasing member and the surface to be discharged electrostatically.

[0015] In one embodiment, the electrostatic discharge device further comprises a grounding assembly fixedly arranged on the electrostatic discharge assembly, one end of the grounding assembly is electrically connected with the electrostatic discharge assembly, and the other end of the grounding assembly is electrically connected with the outer shell of the product taking and placing device.

[0016] In one embodiment, the releasing member comprises a releasing unit, and the electrostatic contact surface of the releasing unit has a plating layer which is a gold plating layer or a rhodium plating layer.

[0017] In one embodiment, the connecting assembly comprises:

[0018] The first connecting member has a bending angle of 90°.

[0019] The second connecting member is fixedly connected with the other end of the first connecting member, is arranged in extension along the Z axis and is closer to the surface to be discharged electrostatically; and

[0020] The third connecting member is fixedly connected with the second connecting member, has a bending angle of 90° and has an extension surface in the X-Y plane, one end of the third connecting member is fixedly connected with the end of the second connecting member arranged in extension along the Z axis, and the other end of the third connecting member is fixedly connected with the electrostatic discharge assembly.

[0021] In one embodiment, the third connecting member further comprises a bearing plate arranged in extension along the X axis.

[0022] The bearing plate has a plurality of through holes arranged at intervals, and each through hole is provided with a releasing member.

[0023] The release member further comprises:

[0024] The release assembly is formed by combining the red copper block and the high-density copper wire; the size of the release assembly in the Z-axis direction is the same as the size of the release monomer in the Z-axis direction.

[0025] In one embodiment, the third connecting member further comprises a bearing plate arranged along the X-axis direction;

[0026] The bearing plate is provided with a plurality of through holes arranged at intervals, and each through hole is provided with a release member;

[0027] The release member comprises:

[0028] at least one release monomer; and,

[0029] at least one release assembly formed by combining a red copper block and a high-density copper wire;

[0030] The contact area between the release monomer and the surface to be released static electricity is located in the product edge area, and the contact area between the release assembly and the surface to be released static electricity is located in the product pattern area.

[0031] In one embodiment, the connecting assembly comprises:

[0032] A fourth connecting member, one end of the fourth connecting member is fixedly connected with the driving assembly; the fourth connecting member has a bending angle of 90°; and,

[0033] A fifth connecting member, fixedly connected with the other end of the fourth connecting member;

[0034] The release member comprises:

[0035] A first release element, fixedly arranged on the fifth connecting member; and,

[0036] A second release element, connected with the first release element, the second release element has a third buffer height h3 in the Z-axis direction.

[0037] In one embodiment, the fifth connecting member comprises:

[0038] A connecting body, arranged along the X-axis direction;

[0039] A plurality of connecting columns, integrally formed with the connecting body, and each connecting column is fixedly connected with a first release element.

[0040] In one embodiment, each electrostatic discharge assembly is connected with a grounding assembly;

[0041] The grounding assembly comprises: independent multi-strand tinned copper braid connected to a common grounding busbar; and the resistance of the grounding loop is less than 1Ω.

[0042] The application also includes an electrostatic discharge method of a metal mask, using the electrostatic discharge device of the metal mask according to any one of the preceding aspects,

[0043] The method comprises:

[0044] S01, driving the electrostatic discharge assembly to move downward along the Z-axis direction at a first speed to the surface of the metal mask product, and detecting and feeding back the height value of the electrostatic discharge assembly in real time; when the lower end of the electrostatic discharge assembly is at a first distance from the surface of the metal mask product, automatically switching to a second speed, wherein the second speed is less than the first speed;

[0045] S02, detecting the pressure value borne by the electrostatic discharge assembly at multiple positions, and switching to a pressure closed-loop mode when the pressure value at any position reaches a first pressure value;

[0046] S03, the pressure closed-loop mode comprises: setting a target pressure as a standard pressure value, dynamically adjusting the output force of the driving assembly in the Z-axis direction, so that the pressure values borne by the multiple positions are uniform; and when the pressure values borne by the multiple positions are uniform, it is determined that the electrostatic discharge assembly is in stable contact with the surface of the metal mask product;

[0047] S04, continuously monitoring the surface voltage of the metal mask product, the cumulative release time, and the voltage decay slope; and when any one of the three parameters meets a constraint condition, controlling the electrostatic discharge assembly to lift along the Z-axis at a third speed, wherein the third speed is greater than the first speed.

[0048] The electrostatic discharge device and method of the metal mask provided by the application have at least the following advantages or beneficial effects:

[0049] 1. The electrostatic discharge device of the metal mask provided by the application directly discharges the charges on the surface of the product through the electrostatic discharge assembly, thereby reducing the static adsorption component on the surface of the product. The electrostatic discharge assembly in the electrostatic discharge device can be in buffer contact with the surface to be discharged, and can achieve the buffering of the first buffer height, so that the position deviation is dynamically compensated while the electrostatic charges are discharged. The electrostatic discharge assembly can be in buffer contact with the surface to be discharged, which can avoid hard collision and mechanical contact during the contact process, thereby avoiding scratching / pollution of the product surface, and further improving the product yield.

[0050] 2、The electrostatic discharge device of the metal mask provided in the application can stably discharge the charge through the stable buffering contact of the electrostatic discharge assembly and the surface to be discharged, and has zero damage (the electrostatic discharge assembly can realize the buffering of the first buffering height h1) when physically contacting the metal mask product. The shell of the product taking and placing device is electrically connected through the grounding assembly, a millisecond-level charge direct current path is formed, and thus the electrostatic adsorption of the metal mask product is eliminated (the electrostatic residue is cancelled). Without roughening the surface of the glass stage, the flatness precision of the glass stage can be ensured to be in the nanometer level. The electrostatic discharge device provided in the embodiment provides a bottom technology guarantee for the manufacturing of metal masks such as Micro LED and OLED, improves the yield of the metal mask, and directly reduces the cost of a single metal mask.

[0051] 3、The electrostatic discharge device of the metal mask provided in the application has the first buffering height in the Z-axis direction, which can ensure that when the release member is lowered or the product is raised to produce surface contact, even if the product surface or the glass stage is slightly uneven, each release member can uniformly contact the product surface under the elastic pressure. In addition, in the embodiment, a pressure detection module and / or a voltage detection module can be further arranged to monitor the relationship between the buffering height of the release member in the Z-axis direction, the pressure value of the product, and the charge of the product surface. On the one hand, the height of the release member in the Z-axis direction can be accurately controlled, the charge amount of the product surface can be monitored, and it can be determined whether the residual static electricity is completely released. On the other hand, by monitoring the pressure value between the release member and the product surface and the charge amount of the product surface in real time, the dynamic relationship between the height value of the release member on the product surface and the charge amount of the product surface can be balanced, so that the residual static electricity can be completely released, and the product surface can be prevented from being damaged. In the embodiment, the displacement, the pressure value, and the residual charge amount can be realized through the automatic control system, and the three parameters are closed-loop controlled, so that the process can be traced and the abnormality can be warned. Further, the electrostatic discharge assembly completes a single lifting action in the Z-axis direction, synchronously completes the electrostatic discharge of the product surface and the weakening of the adsorption force between the glass stage and the product surface, and the electrostatic removal efficiency is greatly improved. BRIEF DESCRIPTION OF DRAWINGS

[0052] In order to more clearly illustrate the technical solutions in the specific embodiments of the present application or the prior art, the drawings needed in the description of the specific embodiments or the prior art will be briefly introduced. Obviously, the drawings in the following description are some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creative labor.

[0053] Figure 1a The front view of the electrostatic discharge device provided in an embodiment of the present application;

[0054] Figure 1b A side view of an electrostatic discharge device according to an embodiment of the present application;

[0055] Figure 2 A structural schematic diagram of an electrostatic discharge assembly and a grounding assembly according to an embodiment of the present application;

[0056] Figure 3 A structural schematic diagram of an electrostatic discharge assembly arranged on a carrier plate according to an embodiment of the present application;

[0057] Figure 4 A structural schematic diagram of an electrostatic discharge assembly arranged on a carrier plate according to another embodiment of the present application;

[0058] Figure 5 A structural schematic diagram of an electrostatic discharge assembly arranged on a carrier plate according to yet another embodiment of the present application;

[0059] Figure 6a A partial structural schematic diagram of an electrostatic discharge device according to another embodiment of the present application;

[0060] Figure 6b A structural front view of an electrostatic discharge device according to another embodiment of the present application;

[0061] Figure 7 A structural schematic diagram of a connecting assembly in an electrostatic discharge device according to another embodiment of the present application;

[0062] Figure 8 A structural side view of an electrostatic discharge device according to another embodiment of the present application;

[0063] Figure 9 A top view of a product taking and placing device when picking up or placing down a metal mask product according to an embodiment of the present application;

[0064] Figure 10 A top view of an electrostatic discharge device when performing electrostatic discharge on a metal mask product according to an embodiment of the present application.

[0065] Explanation of reference numerals:

[0066] Product taking and placing device 100, suction cup 101, electrostatic discharge device 200, glass carrier 301, electrostatic buffer film 302, metal mask 303;

[0067] Driving assembly 10;

[0068] Connecting assembly 20:

[0069] First connecting member 21, second connecting member 22, third connecting member 23: carrier plate 231;

[0070] Fourth connecting member 24, fifth connecting member 25: connecting body 251, connecting column 252;

[0071] Electrostatic discharge assembly 30: telescopic member 31, fixing member 32, discharge member 33:

[0072] Discharge monomer 331,

[0073] Discharge assembly 332: red copper block 332-1, copper wire 332-2;

[0074] First discharge element 34: main body copper band 341, cladding copper band 342, second discharge element 35;

[0075] Grounding assembly 40: grounding member 41, grounding connecting body 42. DETAILED DESCRIPTION

[0076] To make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the following will be a clear and complete description of the technical solutions in the embodiments of the present application in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings can be arranged and designed in various different configurations.

[0077] Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without making creative efforts fall within the scope of protection of the present application.

[0078] It should be noted that: similar reference numbers and letters represent similar items in the following drawings, therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0079] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship when the product of the present application is usually placed, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third" and the like are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0080] In addition, the terms "horizontal", "vertical", and the like do not mean that the components must be absolutely horizontal or vertical, but can be slightly inclined. For example, "horizontal" only means that it is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly inclined.

[0081] In the description of the present application, it should be further pointed out that unless otherwise explicitly specified and limited, the terms "arrangement", "installation", "connection", "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integral connection; it can be mechanical connection, or electrical connection; it can be direct connection, or indirect connection through intermediate medium, or internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0082] For the first problem involved in the background art: the problem of negative pressure between the product and the glass platform surface, the existing solution usually roughens the surface of the glass platform by physical or chemical roughening to increase the surface roughness, so as to promote the faster entry of air into the gap between the product and the glass platform after static electricity is turned off, thereby reducing the negative pressure adsorption force. However, this method has obvious limitations: surface roughening may affect the flatness of the glass platform, resulting in uneven product adhesion, and thus affecting the processing precision. At the same time, the roughness is limited, the air permeation speed is still slow, and the negative pressure adsorption effect cannot be completely eliminated, and there is still a risk of local product deformation caused by pulling during unloading.

[0083] For the second problem involved in the background art: the problem of static electricity residue, some existing technical solutions in the prior art include adding a contact type static electricity removal mechanism to the laser equipment, such as using a hard conductor to remove residual charge by directly contacting the product. However, this method has the following disadvantages: contact type static electricity removal may cause scratches or contamination on the surface of the product due to mechanical contact. The hard conductor needs to be accurately aligned, otherwise the static electricity removal may not be complete due to poor contact. It can only eliminate static electricity residue, but cannot solve the problem of negative pressure adsorption at the same time, and the product may still be damaged due to the combined adsorption force during unloading.

[0084] In summary, the existing technology cannot efficiently solve the problems of negative pressure adsorption and static electricity residue at the same time, and there is a risk of decreased processing precision and secondary damage to the product, so a more reliable and non-contact solution is needed. In the embodiments of the present application, the paradox that "surface treatment precision and static electricity removal efficiency cannot be considered together" is solved: the traditional solution sacrifices platform flatness (roughening) or increases the risk of contact damage (hard contact) to improve the static electricity removal effect. The static electricity release device provided in the embodiments of the present application achieves nanometer-level processing precision guarantee while zeroing damage through non-invasive charge conduction and adaptive buffering.

[0085] Please refer toFigure 1a and Figure 1b The application provides an electrostatic discharge device 200 of a metal mask. The electrostatic discharge device 200 is integrated on a product taking and placing device 100. The product taking and placing device 100 comprises a driving assembly 10 and a connecting assembly 20. The electrostatic discharge device 200 comprises an electrostatic discharge assembly 30.

[0086] The driving assembly 10 is used to realize the lifting of the product taking and placing device in the Z-axis direction. The driving assembly is also used to control the lifting of the electrostatic discharge assembly 30 in the Z-axis direction in the electrostatic discharge device 200. The driving assembly 10 can be provided as a driving cylinder, and the driving assembly 10 is fixedly connected to the product taking and placing device 100, and is used to control the lifting of the copper block of the electrostatic discharge assembly 30 in the Z-axis direction. The driving assembly 10 is controlled by a controller, and the repeated positioning accuracy of the driving assembly 10 is ±0.01 mm. The driving assembly 10 can realize nanoscale action control, and the Z-axis lifting period is ≤0.5 s, which can be combined with the production line of the metal mask. The abnormal response speed of the driving assembly 10 is <10 ms.

[0087] The connecting assembly 20 is fixedly connected with the driving assembly 10. The connecting assembly 20 is also fixedly connected with the electrostatic discharge assembly 30 in the electrostatic discharge device 200. The connecting assembly 20 is fixedly connected with the driving assembly 10 (such as a driving cylinder) and the electrostatic discharge assembly 30 (such as a copper block) respectively. The electrostatic discharge assembly 30 is fixedly arranged on the connecting assembly 20, and the electrostatic discharge assembly 30 can be in contact with the surface to be discharged electrostatically in a buffering manner, and the first buffering height h1 can be realized.

[0088] Please further refer to Figure 2 and Figure 3 The electrostatic discharge assembly 30 comprises a telescopic part 31, a fixing part 32 and a discharging part 33.

[0089] The telescopic part 31 has a fixed shell and a telescopic shaft. The telescopic shaft can be elongated or shortened in the fixed shell. As shown in Figure 2 The fixed shell has an external thread, which is used to be fixedly connected with the fixing part 32. The telescopic part 31 passes through the through hole of the connecting assembly 20. The telescopic shaft can comprise a precision spring. The fixing part 32 can be provided as a fixing screw, and the fixing part 32 is used to fix the telescopic part 31 on the connecting assembly 20. The discharging part 33 is fixedly arranged on the end of the telescopic shaft. When the discharging part 33 is in contact with the surface to be discharged electrostatically, the telescopic shaft is elongated or shortened in the fixed shell, so as to buffer the contact force between the discharging part 33 and the surface to be discharged electrostatically. As shown in Figure 2As shown, the release member 33 can be driven by the telescopic shaft to achieve a first buffer height h1. In some embodiments, the first buffer height h1 is 1-5 mm. That is, the release member 33 has an independent buffer stroke of 1-5 mm in the direction perpendicular to the product surface (Z-axis direction). The release member 33 can be selected as a high-purity red copper block, and the red copper has a low resistivity of 1.68 x 10 -8 Ω·m, so as to achieve millisecond-level charge release (<0.2 s).

[0090] In this embodiment, the electrostatic discharge assembly 30 in the electrostatic discharge device 200 can be in buffer contact with the surface to be discharged of static electricity, and can achieve a first buffer height of buffer, so as to dynamically compensate for the position deviation while releasing the electrostatic charge. The electrostatic discharge assembly 30 can be in buffer contact with the surface to be discharged of static electricity, which can avoid hard collision and mechanical contact during contact, thereby avoiding scratching / pollution of the product surface, and further improving the product yield.

[0091] In one embodiment, the electrostatic discharge device 200 further includes a grounding assembly 40. The grounding assembly 40 is fixedly arranged on the electrostatic discharge assembly 30. One end of the grounding assembly 40 is electrically connected with the electrostatic discharge assembly 30, and the other end of the grounding assembly 40 is electrically connected with the outer shell of the product pick-and-place device 100, so as to avoid breakdown of electronic devices, damage to the performance of electronic devices, or electromagnetic interference (EMI) of the metal mask during production / testing, thereby causing the production line to stop. The grounding assembly 40 directly conducts the residual charge to the equipment shell, synchronously collapses the electrostatic adsorption force, so that the product is no longer pulled by the combined force of "static electricity + negative pressure" when it is separated, thereby eliminating the risk of product deformation from the root.

[0092] The electrostatic discharge device 200 provided in this embodiment can maintain the original flatness of the glass stage 301, without the need for roughening treatment of the glass stage 301, and 100% preserves the optical-grade flat surface, so as to ensure the uniformity of the product and the glass stage 301, and avoid micron-level processing deviation caused by rough surface of the glass stage 301.

[0093] The electrostatic discharge device 200 provided in the embodiment directly discharges the charge on the product surface through the electrostatic discharge assembly 30, thereby reducing the static adsorption component of the product surface. The grounding path is formed by the grounding assembly 40, and the accumulation of charge near the electrostatic discharge assembly 30 / near the grounding assembly 40 is cut off, so that the adsorption voltage of the product surface loses the electrostatic synergistic effect. That is, through the synergistic cooperation of the electrostatic discharge assembly 30 and the grounding assembly 40, the electrostatic adsorption force on the product surface is simultaneously eliminated. The electrostatic discharge assembly 30 in the electrostatic discharge device 200 can be in buffer contact with the surface to be discharged, and can achieve the first buffer height h1 of the buffer, so as to dynamically compensate the position deviation while discharging the electrostatic charge. The electrostatic discharge assembly 30 can be in buffer contact with the surface to be discharged, which can avoid hard collision and mechanical contact during contact, thereby avoiding scratching / pollution of the product surface, and further improving the product yield.

[0094] In the embodiment, the electrostatic discharge assembly 30 is in stable buffer contact with the surface to be discharged to stably discharge the charge, and has zero damage when physically contacting the metal mask product (the electrostatic discharge assembly 30 can achieve the first buffer height h1 of the buffer). The grounding assembly 40 is electrically connected with the housing of the product taking and placing device 100, and forms a millisecond-level charge direct current path, thereby eliminating the static adsorption of the metal mask product (cancelling the electrostatic residue). Without roughening the surface of the glass stage 301, the flatness accuracy of the glass stage can be ensured to be in the nanometer level. The electrostatic discharge device 200 provided in the embodiment provides a bottom technology guarantee for the manufacturing of Micro LED, OLED and other metal masks, so as to improve the yield of the metal mask, and directly reduce the single-piece cost of the metal mask.

[0095] In one embodiment, the electrostatic discharge assembly 30 (which can include a plurality of release elements 33 and / or a plurality of second release elements 35) forms a large-area equipotential contact with the product surface, and the charge release efficiency is greatly improved. The electrostatic discharge is completed within the lifting cycle of the driving assembly 10 (usually <0.5s), and seamlessly connects the production line beat. The grounding path of the grounding assembly 40 is directly coupled with the equipment housing of the product taking and placing device 100, thereby preventing electromagnetic interference (EMI) from being conducted to sensitive electronic elements, and reducing the shutdown rate of the production line caused by electrostatic breakdown to near zero.

[0096] In the embodiment, the electrostatic discharge assembly 30 has a first buffer height h1 in the Z-axis direction (perpendicular to the product surface direction), which can ensure that when the release piece 33 is lowered or the product is raised to produce surface contact, even if the product surface or glass platform 301 has a slight unevenness, each release piece 33 can uniformly contact the product surface under elastic pressure. In addition, in the embodiment, a pressure detection module and / or a voltage detection module can be further provided to monitor the relationship between the buffer height of the release piece 33 in the Z-axis direction, the pressure value of the product, and the charge of the product surface. On the one hand, the height of the release piece 33 in the Z-axis direction can be accurately controlled, the charge of the product surface can be monitored, and it can be determined whether the residual static electricity is completely discharged. On the other hand, by monitoring the pressure value between the release piece 33 and the product surface in real time, and the charge of the product surface, the dynamic relationship between the height value of the release piece 33 on the product surface and the charge of the product surface can be balanced, so that the residual static electricity can be completely discharged, and the product surface can be prevented from being crushed. In the embodiment, the displacement, pressure value, and residual charge can be automatically controlled by an automatic control system, and closed-loop control of the three parameters can be realized, and process traceability and abnormal early warning can be realized. Further, the electrostatic discharge assembly 30 completes a single lifting action in the Z-axis direction, synchronously completes the electrostatic discharge of the product surface, and weakens the adsorption force between the glass platform 301 and the product surface, and the electrostatic removal efficiency is greatly improved.

[0097] In some embodiments, the release piece 33 is a hollow cylindrical structure, and the hollow position in the middle allows the telescopic piece 31 to be arranged therein. The telescopic piece 31 further includes a limiting piece arranged at one end close to the release piece. The grounding assembly 40 includes a grounding piece 41, a grounding connecting body 42, and a grounding wire (not shown in the figure). The grounding piece 41 has a bending angle of 90° and a through hole in a first extension plane perpendicular to the Z-axis direction, and the limiting piece of the telescopic piece 31 is located in the through hole for limiting the continuous extension of the telescopic piece 31 in the Z-axis direction. The grounding piece 41 has a mounting hole of the grounding connecting body 42 in a second extension plane perpendicular to the first extension plane, and the grounding connecting body 42 can be arranged as a screw (hexagonal screw) for fixing the grounding wire. Each release piece 33 can be independently connected to a grounding wire with a sufficient cross-sectional area (such as a cross-sectional area ≥4mm 2The plurality of release pieces 33 can be connected in parallel to the low-resistance copper bus bar. In one embodiment, a high-purity red copper block with a hollow cylindrical structure having only one top surface is used as a release piece 33. The connection point between a release piece 33 and the grounding piece 41 can be obtained by drilling a hole in the center of the top surface of the release piece 33 and then using a stainless steel screw, a star washer, and a conductive gasket to press the braided grounding wire terminal, thereby ensuring firm and low-resistance connection. If multiple release pieces 33 are provided, it is necessary to absolutely avoid connecting the high-purity red copper block in series with a wire and then grounding it, which will result in a long release path, large resistance, and poor effect for the copper block far from the grounding point.

[0098] In the present embodiment, the electrostatic discharge assembly 30 includes a retractable piece 31, a fixed piece 32, and a release piece 33. The grounding assembly 40 includes a grounding piece 41, a grounding connector 42, and a grounding wire (not shown). The connection between the electrostatic discharge assembly 30 and the grounding assembly 40 makes the connection between the electrostatic discharge assembly 30 and the grounding assembly 40 more firm, the connection resistance lower, the path for discharging electrostatic current via the electrostatic discharge assembly 30 shorter, and the electrostatic discharge effect better.

[0099] A plating layer can be provided on the surface of the release piece 33 that directly contacts the metal mask product, which can prevent copper oxidation from causing an increase in contact resistance and ensure long-term stable and reliable contact. An insulating ceramic coating is provided on the area of the release piece 33 that does not directly contact the metal mask product, so that the release piece 33 has an anti-interference shielding effect. On the one hand, it can block high-frequency interference and suppress electromagnetic pulses during discharge. On the other hand, the insulating ceramic coating has a voltage resistance > 15 kV, which can prevent high-voltage equipment from being triggered by mistake.

[0100] Please refer to Figure 2 , Figure 3 , Figure 4 and Figure 5 . In one embodiment, as shown in Figure 2 , the electrostatic discharge assembly 30 includes one release piece 33 (the release piece 33 is provided as a release monomer 331). In some embodiments, as shown in Figure 3 , Figure 4 and Figure 5 , the electrostatic discharge assembly 30 includes a plurality of release pieces 33 arranged at intervals. Figure 3 In the embodiment shown in Figure 4 , the plurality of release pieces 33 arranged at intervals are each provided as a release monomer 331. Figure 5 In the embodiment shown in Figure 2 and Figure 3 , the electrostatic discharge assembly 30 includes both a release piece 33 composed of a plurality of release monomers 331 and a release piece 33 composed of a plurality of release combination bodies 332.In the embodiment shown, the release monomer 331 can be provided as a cylindrical hollow block of red copper or high-purity oxygen-free copper structure to ensure optimal electrical conductivity. The static contact surface of the release monomer 331 (the surface of the release monomer 331 directly contacting the metal mask product) is provided with a plating layer, which is a gold plating layer or a rhodium plating layer. In one embodiment, a cylindrical hollow block structure of red copper with a diameter of 15 mm to 25 mm can be provided as the release monomer 331. The static contact surface of the release monomer 331 can be finely polished. In some embodiments, the thickness of the gold plating layer or the rhodium plating layer is greater than 1 μm.

[0101] In the embodiment shown, the surface of the release monomer 331 directly contacting the metal mask product is provided with a plating layer, which can prevent copper oxidation from causing an increase in contact resistance and ensure long-term stable and reliable contact. The gold plating layer or the rhodium plating layer needs to have a certain wear resistance, which can prolong the service life of the release monomer 331.

[0102] Please refer to Figure 1a and Figure 1b In one embodiment, the connecting assembly 20 includes a first connecting piece 21, a second connecting piece 22, and a third connecting piece 23. One end of the first connecting piece 21 is fixedly connected to the cylinder of the driving assembly 10. The first connecting piece 21 has a bending angle of 90°. The other end of the first connecting piece 21 is fixedly connected to the second connecting piece 22. The second connecting piece 22 is arranged to extend along the Z-axis direction and is closer to the surface to be released of static electricity. The third connecting piece 23 is fixedly connected to the second connecting piece 22. The third connecting piece 23 also has a bending angle of 90°. The third connecting piece 23 has an extension surface in the plane of X-Y. One end of the third connecting piece 23 is fixedly connected to the end of the second connecting piece 22 arranged to extend along the Z-axis, and the other end of the third connecting piece 23 is fixedly connected to the static electricity release assembly 30 arranged to extend along the Z-axis direction.

[0103] Specifically, as shown in Figure 1b The first connecting piece 21 and the third connecting piece 23 each have a portion arranged to extend along the Y-axis direction. The third connecting piece 23 also has a portion arranged to extend along the X direction. The first connecting piece 21 and the second connecting piece 22 can be made of high-resistance alloy or resistance alloy (such as nickel-chromium alloy, copper-nickel alloy, iron-chromium-aluminum alloy, etc.). The third connecting piece 23 can be made of copper, copper alloy (such as beryllium copper alloy, copper-nickel-silicon alloy, copper-chromium-zirconium alloy), nickel, nickel alloy (such as nickel-titanium alloy or palladium-nickel alloy), tungsten, tungsten alloy (such as copper-tungsten alloy), or other metal or alloy materials with good electrical conductivity. The above-mentioned portion of the connecting assembly 20 can be in contact with or arranged side by side with the product taking and placing device 100, so as to save space of the static electricity release device 200 and the product taking and placing device 100.

[0104] Please refer to Figure 3 , Figure 4 andFigure 5 In one embodiment, the third connecting member 23 further comprises a bearing plate 231 extending along the X direction (positive X-axis direction and negative X-axis direction). The bearing plate 231 has a plurality of through holes arranged at intervals, and each through hole is provided with a release member 33. In this embodiment, a plurality of arrayed release members 33 can be included. The extension length of the third connecting member 23 along the X direction can be designed according to the product size. In this embodiment, the structure of the third connecting member 23 can be provided with a larger number of different forms of release members 33, which can improve the static discharge efficiency. Figure 1a

[0105] The release member 33 further comprises a release combination body 332 of a red copper block 332-1 and a high-density copper wire 332-2. The solid red copper block 332-1 can be welded with the high-density copper wire 332-2. The high-density copper wire 332-2 can be set as a brass wire with a wire diameter of 0.1, and the length is 10mm-80mm which can be selected according to actual needs. The density of the high-density copper wire 332-2 is 90 roots / mm 2 -150 roots / mm 2 , such as 120 roots / mm 2 . The high-density copper wire 332-2 can achieve a second buffer height h2 in the Z-axis direction, wherein the second buffer height can reach 0.5mm-1.5mm. The size of the release combination body 332 in the Z-axis direction is the same as the size of the release monomer 331 in the Z-axis direction. The red copper block 332-1 can be set as a cylindrical shape, a cubic shape or other shapes. The red copper block 332-1 can be set as a hollow red copper block or a solid red copper block. As shown in Figure 3 A plurality of release members 33 are arranged at intervals on the bearing plate 231. As shown in Figure 4 A plurality of release combination bodies 332 are arranged at intervals on the bearing plate 231. As shown in Figure 5 A plurality of release monomers 331 and a plurality of release combination bodies 332 are arranged at intervals on the bearing plate 231, wherein the positions of the release monomers 331 and the release combination bodies 332 can be interchanged.

[0106] In this embodiment, the bearing plate 231 included in the third connecting member 23 can be set as a long strip-shaped base, for example, the length is slightly less than 1200mm, such as 1150mm, and a plurality of independent release monomers 331 or release combination bodies 332 including a cylindrical solid red copper block 332-1 and a high-density copper wire 332-2 are vertically fixed at intervals of 150mm-250mm. The overall contact area of the release member 33 with the static surface to be released is in the range of 100mm 2 -180mm 2 . In one specific embodiment, the overall contact area of the release member 33 with the static surface to be released is 150mm 2 ​The thickness of the releasing member 33 can be set to 10 mm. The thickness of the releasing member 33 can ensure the rigidity and heat dissipation of the static electricity releasing assembly 30. The contact area of the releasing member 33 with the surface to be released of static electricity ensures that the static electricity releasing assembly 30 has sufficient releasing current density. In the embodiment, the releasing member 33 is provided in combination of the releasing single body 331 and the releasing combination body 332, which on one hand facilitates observation or detection of the displacement of the releasing member 33 when the releasing member 33 is in contact with the surface to be released of static electricity (which can be reflected by whether the releasing combination body 332 is deformed or not), and on the other hand facilitates sufficient releasing of static electricity by the combination of the releasing single body 331 and the releasing combination body 332.

[0107] Please refer to Figure 6a 、 Figure 6b 、 Figure 7 and Figure 8 In one embodiment, the connecting assembly 20 comprises a fourth connecting member 24 and a fifth connecting member 25. One end of the fourth connecting member 24 is fixedly connected with the cylinder of the driving assembly 10. The fourth connecting member 24 has a bending angle of 90°. The fifth connecting member 25 is fixedly connected with the other end of the fourth connecting member 24.

[0108] The static electricity releasing assembly 30 comprises a first releasing element 34 and a second releasing element 35. The first releasing element 34 is fixedly arranged on the fifth connecting member 25. The second releasing element 35 is connected with the first releasing element 34. The second releasing element 35 has a third buffer height h3 in the Z-axis direction, wherein the second buffer height can be 2 mm-10 mm. The contact area of the second releasing element 35 with the surface to be released of static electricity is 40 mm 2 -80 mm 2 In one specific embodiment, the contact area of the second releasing element 35 with the surface to be released of static electricity is 70 mm 2 . Specifically, the first releasing element 34 and the second releasing element 35 can both be made of copper. The second releasing element 35 can be provided as a copper strip with a certain width, which is wound into a hollow ring with a hollow in the middle. Figure 6b As shown in the figure, the first releasing element 34 can comprise a main copper strip 341 and a cladding copper strip 342. The main copper strip 341 is directly fixedly connected with the fifth connecting member 25. The cladding copper strip 342 is arranged outside the main copper strip 341 and wraps the main copper strip 341 and part of the fifth connecting member 25. The cladding copper strip 342 is used to reinforce the connection between the main copper strip 341 and the fifth connecting member 25.

[0109] In the embodiment, another detailed structure of the static electricity releasing device 200 is provided, which has simpler specific structures of the connecting assembly 20 and the static electricity releasing assembly 30 and can also achieve high-efficiency static electricity releasing. In the embodiment, the third buffer height h3 in the Z-axis direction is achieved by the second releasing element 35.

[0110] Referring to Figure 7 and Figure 8 In one embodiment, the fifth connecting member 25 comprises a connecting body 251 and a plurality of connecting columns 252. The connecting body 251 extends along the X-axis direction. The plurality of connecting columns 252 are integrally formed with the connecting body 251, and each connecting column 252 is fixedly connected with one first release element 34. The plurality of connecting columns 252 are arranged at intervals, and each connecting column 252 is further provided with a grounding assembly 40. Specifically, the grounding assembly 40 can be wound on the connecting column 252, and the grounding assembly 40 is further fixed by the copper cladding band 342.

[0111] In this embodiment, the specific structure of the fifth connecting member 25 is provided, and the connection mode between the grounding assembly 40 and the fifth connecting member 25 is clarified. In this embodiment, the structure design of the fifth connecting member 25 makes it easier to install the first release element 34 and the second release element 35, and thus it is easier to achieve electrostatic discharge of the metal mask product.

[0112] Referring to Figure 6a , Figure 6b and Figure 8 In one embodiment, each electrostatic discharge assembly 30 is connected with one grounding assembly 40. The grounding assembly 40 comprises an independent multi-strand tinned copper braided band with an impedance <0.1Ω. The cross-sectional area of the grounding assembly 40 is ≥4mm 2 . The grounding assembly 40 can be connected to a common grounding bus copper bar. The grounding assembly 40 can also be connected to the product taking and placing device 100. The grounding loop formed by the grounding assembly 40 has an electrical resistance of less than 1Ω, and more desirably, the grounding resistance value is <0.5Ω. The grounding resistance can be monitored at all times during the process of removing static electricity. For example, a real-time monitoring module can be integrated in the grounding loop, and when the grounding resistance abnormally rises, such as >1.5Ω, an audible and visual alarm is issued. In this embodiment, through the optimized arrangement of the grounding assembly 40, an ultra-low impedance grounding path can be formed, and after being led out through the grounding assembly 40, the residual voltage on the surface of the metal mask product is reduced to <0.03kV, and the false triggering caused by electromagnetic interference is eliminated. The fatigue life of the grounding assembly 40 is long, and specifically, the bending life is greater than 1 million times, and the maintenance period is long. After installation of the grounding assembly 40, a grounding resistance tester is used for measurement and recording, and periodic review is performed, such as monthly review.

[0113] Table 1: Comparison of technical effects of traditional scheme and scheme of the present application.

[0114]

[0115] In the above table 1, the scheme of the present application adopts the embodiment shown in the present application Figures 1a-5 , and Figures 6a-8The illustrated embodiment shows that, compared to conventional solutions, the static electricity removal time in this application is significantly reduced, the product damage rate is greatly decreased, and the frequency of production line downtime is significantly reduced. In a single production line downtime incident using the conventional solution, the production line for metal photomasks was shut down for 8 hours, resulting in a large number of defective products, extended product delivery time, and reduced production efficiency. After adopting the solution in this application, the production line for metal photomasks has not experienced any downtime, the static electricity removal time for each product is significantly shortened, and the product damage rate is also reduced, fully meeting current production needs.

[0116] In this embodiment, a multi-point contact design is used to cover a long-sized metal mask product, thereby increasing the contact area of ​​the antistatic contact surface (e.g., Figures 1a-5 In the embodiment shown, the contact area between the electrostatic discharge component 30 and the surface to be discharged is 100 mm². 2 -180mm 2 ,like Figures 6a-8 In the embodiment shown, the contact area between the electrostatic discharge component 30 and the surface to be discharged is 40 mm². 2 -80mm 2 Gold plating on the surface of the release monomer 331 ensures low contact resistance and improves electrostatic discharge efficiency, while also enhancing oxidation resistance and allowing for regular maintenance to maintain electrostatic discharge performance.

[0117] In several embodiments of this application, the electrostatic discharge assembly 30 has a first buffer height h1 of 1mm-5mm in some embodiments. In other embodiments, the electrostatic discharge assembly 30 has a buffer height of 1mm-6.5mm (first buffer height h1 + second buffer height h2). In still other embodiments, the electrostatic discharge assembly 30 has a third buffer height h3 of 2mm-10mm. This buffer design enables more uniform surface contact, ensuring uniform pressure at all points on the surface of the metal mask product. It also facilitates gradual release of static electricity, avoids sparks, and allows for monitoring and standardized operation during the electrostatic discharge process.

[0118] This application also provides a method for electrostatic discharge of a metal mask, including:

[0119] The product handling device 100 places the product to be tested onto the glass stage 301. (See also...) Figure 9, glass stage 301 is used to place the metal mask product (metal mask 303 in the figure). The static buffer film 302 is located above the glass stage 301, and the static buffer film 302 uses a PET glue-free static frosted film, and the frosted surface directly contacts the metal mask 303, which is used to improve the negative pressure problem between the metal mask 303 and the glass stage 301. When the metal mask 303 is placed on the glass stage 301, the static buffer film 302 is located between the metal mask 303 and the glass stage 301 in the stacking direction. The metal mask 303 includes a product area and an edge support area, wherein the edge support area is located above the static buffer film 302 to avoid damage to the product area caused by the frosted surface of the static buffer film 302. Correspondingly, when the product taking and placing device 100 acts on the metal mask 303, it also acts on the product area to avoid damage to the product area caused by the suction cup 101 of the product taking and placing device 100.

[0120] The controller controls the application of a positive voltage to the product to be tested to electrostatically attract the product to be tested and perform various tests.

[0121] After the test is completed, the controller controls the working environment humidity to be adjusted to 40%-60%RH. In this step, the working environment humidity at 40%-60%RH can effectively suppress the generation of static electricity and accelerate the weak release of electric charge through the air as a supplement to the static electricity release assembly 30 to release static electricity.

[0122] After the test is completed, the controller controls the ion wind to blow the metal mask product. In this step, an ion wind machine can be installed near the taking station to realize blowing on the taking area of the metal mask product. In this step, the ion wind machine is set to blow the product, which can neutralize the static electricity that may be left on the product or the surrounding insulating material after the static electricity release assembly 30 contacts the product (such as the surface of the glass, the non-conductive part of the product), which is difficult to release by the static electricity release assembly 30, and the friction charge that may be regenerated during the operation. In this step, the ion wind machine is set to blow the product, which can provide double protection.

[0123] The glass stage 301 is located at the first position, and the controller controls the static electricity release device 200 to contact the product to be released for a first time (which can be set to 1s-2s). The static electricity release device 200 is lifted. The glass stage 301 moves to the second position, and the controller controls the static electricity release device 200 to contact the product to be released for a second time (which can be set to 1s-2s). After the static electricity of the metal mask is released, the product taking and placing device 100 takes away the product.

[0124] Please refer to Figure 10 Corresponding to Figure 5Figure 2 is a top view of the electrostatic discharge device 200 in use. The surface of the electrostatic discharge assembly 30 in contact with the metal mask product 303 is either the surface of the release element 331 or the surface of the release assembly 332. Figure 10 In the embodiment shown in Figure 2, the electrostatic discharge assembly 30 with a certain buffer height is used to fully discharge the static electricity of the metal mask product 303, thereby solving the problem of negative pressure and static electricity residue between the product and the surface of the glass platform.

[0125] In one embodiment, the electrostatic discharge device 200 further comprises a pressure sensor and a displacement sensor integrated in the electrostatic discharge assembly 30. The pressure sensor is integrated in the lowermost end of the release element 33 or the second release element 35 in the Z-axis direction, i.e. the surface or the vicinity of the surface in contact with the product. The displacement sensor is integrated in the lowermost end of the third connecting element 23 or the fifth connecting element 25 in the Z-axis direction, to accurately measure the displacement of the electrostatic discharge assembly 30. The electrostatic discharge device 200 further comprises a voltage detector arranged between the glass stage 301 and the metal mask product 303, to detect the static voltage at all times. Alternatively, the electrostatic discharge device 200 further comprises a non-contact electrostatic voltmeter, which quickly scans the surface of the metal mask product before and after the electrostatic discharge by the electrostatic discharge device 200, especially the two ends and the middle of the product, to verify the effect of the electrostatic discharge, i.e. whether the residual voltage on the surface of the metal mask product after being discharged by the grounding assembly 40 is reduced to 0.03 kV or below.

[0126] In this embodiment, the driving assembly 10 is precisely programmed and controlled by the controller, in combination with the real-time feedback of the contact state between the electrostatic discharge assembly 30 and the surface of the product by the pressure sensor, to form a three-parameter closed-loop control of "displacement-pressure-charge", thereby realizing process traceability and abnormal early warning. The displacement-pressure-charge control method comprises:

[0127] The electrostatic discharge method for the metal mask product comprises:

[0128] S01, the controller drives the electrostatic discharge assembly 30 to vertically (in the Z-axis direction) downwardly move towards the surface of the metal mask product at a first speed (which can be set to 0.3 mm / s), and the displacement sensor detects and feeds back the height value of the electrostatic discharge assembly 30 in real time at a frequency of ≥100 Hz. When the lower end of the electrostatic discharge assembly 30 is at a first distance (which can be set to 2.0 mm) from the surface of the product, the micro-motion mode at a second speed (which is smaller than the first speed, and which can be set to 0.1 mm / s) is automatically switched.

[0129] S02, detecting the pressure values borne by the plurality of positions of the electrostatic discharge assembly 30, and switching to the pressure closed-loop mode when the pressure value at any position is detected to reach a first pressure value. Since the electrostatic discharge assembly 30 can include a plurality of release elements 33 or second release elements 35, a pressure sensor can be arranged on each release element 33 or second release element 35. Therefore, when any pressure sensor detects that the pressure value reaches the first pressure value (which can be set to 0.1 N / cm 2 ), it is determined that the initial contact time is reached, and the pressure closed-loop mode is immediately executed.

[0130] The pressure closed-loop mode includes setting the target pressure as a standard pressure value, and dynamically adjusting the output force of the driving assembly 10 in the Z-axis direction to make the pressure values borne by the plurality of positions uniform. The specific implementation method includes: the controller switches to the pressure closed-loop mode, and the target pressure is set as a standard pressure value (the standard pressure value can be set to 4.0±0.3 N / cm 2 -4.8±0.3 N / cm 2 ).

[0131] The controller dynamically adjusts the output force of the driving assembly 10 in the Z-axis direction to make the pressure values of the plurality of pressure detection points uniform (the maximum pressure difference of the plurality of pressure detection points can be set to be ≤1.0 N / cm 2 ). The uniformity of the pressure values borne by the plurality of positions can be understood as the pressure values borne by the plurality of positions tending to the standard pressure value, or as the maximum pressure difference between the pressure values borne by the plurality of positions being less than or equal to 1.0 N / cm 2 .

[0132] If the standard deviation of the pressure of the plurality of pressure detection points continues to be >0.8 N / cm 2 for more than 3 seconds, the tilt compensation algorithm is activated to automatically balance the pressure distribution. The tilt compensation algorithm includes: reading the pressure sensor data of all electrostatic discharge assemblies 30, and performing moving average filtering (window width 0.2 seconds) on each electrostatic discharge assembly 30 to eliminate mechanical vibration noise; calculating the key indicators of the pressure distribution: average pressure, pressure range, and standard deviation; when it is judged that the pressure distribution is significantly uneven through the above key indicators, compensation is started; calculating the pressure deviation of each 30, generating compensation instructions, and performing pressure compensation step by step (first compensating low-pressure points, and then compensating high-pressure points); after the compensation is completed, the effect is verified and iterated, and the single-point pressure value and the pressure oscillation amplitude are monitored in real time during each compensation process. The above tilt compensation algorithm can be integrated in the controller, and when it needs to be activated and executed, the corresponding tilt compensation algorithm module in the controller can be directly called.

[0133] S03, when the pressure values at multiple positions (pressure detection points) are uniform, it is determined that the electrostatic discharge assembly 30 is in stable contact with the surface of the metal mask product, voltage monitoring is performed, and the voltage discharge strategy is adjusted.

[0134] Voltage monitoring and adjustment of the voltage discharge strategy include:

[0135] S031, based on the detection data of the voltage detector, the voltage decay slope S (S = AV / At) is calculated every 0.1 seconds.

[0136] S032, the voltage discharge strategy is dynamically adjusted according to the voltage decay slope:

[0137] When S <-100V / s, the current state is maintained;

[0138] When -100V / s≤S<-50V / s, the electrostatic discharge time is extended by 1 second;

[0139] When S≥-50V / s, the electrostatic discharge assembly 30 is started to vibrate slightly (the micro-vibration can be set to an amplitude of 10μm and a frequency of 50Hz) to accelerate the electrostatic discharge;

[0140] S04, continuously monitor the surface voltage of the metal mask product, the cumulative discharge time, and the voltage decay slope, and when any one of the above three parameters (the surface voltage of the metal mask product, the cumulative discharge time, and the voltage decay slope) meets the constraint condition, the electrostatic discharge assembly 30 is separated from the surface of the metal mask product.

[0141] The constraint condition includes: the surface voltage of the metal mask product is ≤0.03kV; the cumulative discharge time is greater than 10 seconds; and the voltage decay slope |S|<10V / s for more than 3 seconds.

[0142] The specific steps of triggering the separation of the electrostatic discharge assembly 30 from the surface of the metal mask product include: the controller controls the electrostatic discharge assembly 30 to lift along the Z-axis at a third speed (the third speed can be set to 0.5mm / s), and synchronously monitors the voltage rebound value AV_sep at the moment of separation; if |AV_sep|>10V, immediately pause and alarm, and the third speed is greater than the first speed.

[0143] Within a preset time (which can be set to 5 seconds) after the separation is completed, the surface voltage of the metal mask product is detected (which can be achieved by scanning the voltage values of the center and four corners of the product surface with a non-contact electrostatic voltmeter). If the surface voltage of all points |V_residual|≤0.03kV, the electrostatic discharge is completed. If any point exceeds the standard, the secondary discharge process is automatically started (the pressure can be increased by 10%-20%).

[0144] In this embodiment, the electrostatic discharge method of the metal mask uses a "displacement-pressure-charge" three-parameter closed-loop control method. The pressure control can eliminate the scratch of micron-level products. Different displacement amounts in the Z-axis direction use three speeds to avoid the risk of secondary discharge generating electric sparks. The voltage is discharged quickly, and the single operation time is shortened to 1-2 seconds, and the longest is not more than 8.5 seconds. The electrostatic discharge method involved in this application has high integration, and the control process is embedded in the picking action, which is convenient to operate.

[0145] The electrostatic discharge method of the metal mask also includes, after each batch of electrostatic discharge is completed, binding the product ID to store all parameters (displacement / pressure / voltage time sequence data). Automatically generate a process report and mark abnormal events. Trigger an early warning based on rules (such as alarm when residual voltage > 0.03kV for 3 consecutive times).

[0146] In the embodiments of this application, the abnormal event is associated with the original sensor data segment (such as 10s of data before pressure imbalance), which can realize early warning tracing, find the alarm reason, and solve the problem in time.

[0147] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. An electrostatic discharge device for a metal photomask, connected to a product pick-and-place device, the product pick-and-place device comprising: A drive assembly (10) is used to realize the lifting and lowering of the product picking and placing device in the Z-axis direction; and, The connecting component (20) is fixedly connected to the driving component (10); The electrostatic discharge device (200) is characterized in that it comprises: An electrostatic discharge assembly (30) is fixedly disposed on the connecting assembly (20), and the electrostatic discharge assembly (30) can be buffered to contact the surface to be discharged static electricity; The electrostatic discharge assembly (30) includes: The telescopic member (31) has a fixed housing and a telescopic shaft, the telescopic shaft being able to extend or shorten along the Z-axis in the fixed housing, the telescopic member (31) passing through the through hole of the connecting assembly (20); Fastener (32) for securing the telescopic member (31) to the connecting assembly (20); and, The release element (33) is fixedly disposed at the end of the telescopic shaft. When the release element (33) comes into contact with the surface to be released static electricity, the telescopic shaft extends or shortens along the Z-axis in the fixed housing to buffer the magnitude of the contact force between the release element (33) and the surface to be released static electricity. The release element (33) includes two types: a release monomer (331) and a release assembly (332); The connecting component (20) includes: a first connector (21), a second connector (22) and a third connector (23); The third connector (23) includes a support plate (231) extending along the X-axis direction; The support plate (231) has a plurality of through holes spaced apart, and each through hole is provided with a release unit (331) or a release assembly (332); the release assembly (332) is formed by combining a copper block (332-1) and a high-density copper wire (332-2); the size of the release assembly (332) in the Z-axis direction is the same as the size of the release unit (331) in the Z-axis direction.

2. An electrostatic discharge device for a metal photomask, connected to a product pick-and-place device, the product pick-and-place device comprising: A drive assembly (10) is used to realize the lifting and lowering of the product picking and placing device in the Z-axis direction; and, The connecting component (20) is fixedly connected to the driving component (10); The electrostatic discharge device (200) is characterized in that it comprises: An electrostatic discharge assembly (30) is fixedly disposed on the connecting assembly (20), and the electrostatic discharge assembly (30) can be buffered to contact the surface to be discharged static electricity; The electrostatic discharge assembly (30) includes: The telescopic member (31) has a fixed housing and a telescopic shaft, the telescopic shaft being able to extend or shorten along the Z-axis in the fixed housing, the telescopic member (31) passing through the through hole of the connecting assembly (20); Fastener (32) for securing the telescopic member (31) to the connecting assembly (20); and, The release element (33) is fixedly disposed at the end of the telescopic shaft. When the release element (33) comes into contact with the surface to be released static electricity, the telescopic shaft extends or shortens along the Z-axis in the fixed housing to buffer the magnitude of the contact force between the release element (33) and the surface to be released static electricity. The release element (33) includes two types: a release monomer (331) and a release assembly (332); The connecting component (20) includes: a first connector (21), a second connector (22) and a third connector (23); The third connector (23) includes a support plate (231) extending along the X-axis direction; The support plate (231) has a plurality of through holes spaced apart, and each through hole is provided with a release unit (331) or a release assembly (332); at least one release unit (331) and one release assembly (332) are provided; the release assembly (332) is formed by combining a copper block (332-1) and a high-density copper wire (332-2); The contact area between the releasing monomer (331) and the surface to which static electricity is to be released is located in the product edge area, and the contact area between the releasing assembly (332) and the surface to which static electricity is to be released is located in the product pattern area.

3. The electrostatic discharge device for a metal mask according to claim 1 or 2, characterized in that, The electrostatic contact surface of the release monomer (331) has a coating, which is a gold plating or a rhodium plating.

4. The electrostatic discharge device for a metal mask according to claim 1 or 2, characterized in that, One end of the first connector (21) is fixedly connected to the drive assembly (10); the first connector (21) has a bending angle of 90°; The second connector (22) is fixedly connected to the other end of the first connector (21), the second connector (22) extends along the Z-axis and is closer to the surface to be released static electricity; and, The third connector (23) is fixedly connected to the second connector (22). The third connector (23) has a bending angle of 90° and an extension surface in the XY plane. One end of the third connector (23) is fixedly connected to the end of the second connector (22) that extends along the Z-axis. The other end of the third connector (23) is fixedly connected to the electrostatic discharge assembly (30).

5. The electrostatic discharge device for a metal mask according to claim 1 or 2, characterized in that, The electrostatic discharge device (200) further includes: a grounding component (40) fixedly disposed on the electrostatic discharge component (30), one end of the grounding component (40) being electrically connected to the electrostatic discharge component (30), and the other end of the grounding component (40) being electrically connected to the outer shell of the product pick-up and place device.

6. The electrostatic discharge device for a metal mask according to claim 5, characterized in that, Each of the electrostatic discharge components (30) is connected to one of the grounding components (40). The grounding assembly (40) includes: an independent multi-strand tin-plated copper braided strip connected to a common grounding busbar.

7. The electrostatic discharge device for a metal mask according to claim 1 or 2, characterized in that, The contact area between the electrostatic discharge component (30) and the surface to which static electricity is to be discharged is 100 mm². 2 -180mm 2 .

8. The electrostatic discharge device for a metal mask according to claim 1 or 2, characterized in that, The release component (33) achieves a first buffer height h1 under the drive of the telescopic shaft, and the first buffer height h1 is 1mm-5mm.

9. The electrostatic discharge device for a metal mask according to claim 1 or 2, characterized in that, The high-density copper wire (332-2) can achieve a second buffer height h2 in the Z-axis direction, and the second buffer height h2 is 0.5mm-1.5mm.

10. The electrostatic discharge device for a metal mask according to claim 1 or 2, characterized in that, The electrostatic discharge assembly (30) has a buffer height of 1mm-6.5mm.

11. A method for electrostatic discharge of a metal photomask, characterized in that, The electrostatic discharge device using the metal mask according to any one of claims 1-10, the method comprising: S01, drive the electrostatic discharge component (30) to move downward along the Z-axis towards the surface of the metal mask product at a first speed, and detect and feedback the height value of the electrostatic discharge component (30) in real time; when the lower end of the electrostatic discharge component (30) is at a first distance from the surface of the metal mask product, automatically switch to the second speed, the second speed being less than the first speed; S02, detect the pressure value of the electrostatic discharge component (30) at multiple locations. When the pressure value at any location reaches the first pressure value, switch to the pressure closed-loop mode. The pressure closed-loop mode includes: setting the target pressure to the standard pressure value and dynamically adjusting the output force of the drive component (10) in the Z-axis direction to make the pressure value at multiple locations uniform. S03, once the pressure values ​​at multiple locations are uniform, it is determined that the electrostatic discharge component (30) is in stable contact with the surface of the metal mask product, voltage monitoring is performed, and the voltage discharge strategy is adjusted. S04, continuously monitor the surface voltage, cumulative release time, and voltage decay slope of the metal mask product. When any one of the above three parameters meets the constraint conditions, control the electrostatic release component (30) to lift along the Z-axis at a third speed, the third speed being greater than the first speed.

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