Alignment system of evaporator

Abstract

The invention provides an alignment system of an evaporator. The alignment system of the evaporator comprises a cavity defined by cavity walls, a top plate is arranged in the cavity, the cavity is divided into two parts by the top plate, the cavity above the top plate is an atmosphere area, and the cavity below the top plate is a vacuum cavity; the vibration isolation system is located in an atmospheric area and used for isolating external disturbance; the six-axis platform is positioned in the atmospheric area and is used for controlling the position and the posture of the to-be-evaporated substrate placed on the six-axis platform; the alignment device comprises an electrostatic chuck and a mask plate tray which are arranged in the vacuum cavity; and the machine vision system is arranged in the vacuum cavity below the mask plate tray and is used for detecting the alignment result of the substrate to be evaporated and the mask plate in real time. By using the alignment system disclosed by the invention, the alignment with the precision of 0.1 mu m between the substrate and the mask plate can be realized, and the preparation requirement of a Micro OLED (Organic Light Emitting Diode) device with a Real RGB (Red, Green, Blue) structure is met.

Description

Technical Field

[0001] The present application relates to the field of vapor deposition technology, and in particular to an alignment system for a vapor deposition machine. Background Art

[0002] Organic light-emitting diode displays have the advantages of low energy consumption, self-luminescence, wide viewing angle and fast response speed. They are one of the hot spots in the current display research field and are considered to be the next generation of display technology. At present, the production of OLED devices usually uses vacuum thermal evaporation equipment to deposit OLED device films. Fine mask plates are tools used to pattern organic pixels during the evaporation process of OLED device production. The use of fine mask plate routes to produce Real RGB structured silicon-based Micro OLEDs requires that the pixel shadow of the OLED device prepared by the required evaporation equipment is less than 0.5μm, and the alignment accuracy of the mask plate and the silicon substrate is less than 0.1μm. The alignment accuracy of the alignment system of traditional evaporation machines is generally 1.5-3μm, which cannot meet the alignment accuracy requirements of high-precision coating machines of less than 0.1μm. Summary of the invention

[0003] In order to solve the above technical problems, the present invention provides a vapor deposition machine alignment system.

[0004] The present invention provides an alignment system for an evaporation machine, comprising: a chamber surrounded by a cavity wall, wherein a top plate is arranged in the chamber, wherein the top plate divides the chamber into two parts, wherein the chamber above the top plate is an atmospheric zone, and the chamber below the top plate is a vacuum chamber; a vibration isolation system located in the atmospheric zone, wherein the vibration isolation system comprises two active isolators respectively arranged at two ends of an upper surface of the top plate, for isolating external disturbances; a six-axis platform located in the atmospheric zone, wherein the six-axis platform comprises, from bottom to top, a first separate base, a motor and a second separate base, for controlling the position and posture of a substrate to be evaporated and placed thereon; an alignment device, wherein the alignment device comprises an electrostatic chuck and a mask plate tray arranged in the vacuum chamber, wherein the electrostatic chuck is used to fix the substrate to be evaporated during the alignment process, and wherein the mask plate tray is used to place the mask plate during the alignment process; and a machine vision system, wherein the machine vision system is arranged in the vacuum chamber below the mask plate tray, for real-time detection of the alignment results of the substrate to be evaporated and the mask plate.

[0005] Optionally, the alignment system also includes: a magnet plate, which is located in the vacuum chamber and is used to adsorb the mask plate on the substrate to be evaporated; an electrostatic chuck lifting device, which is located in the atmospheric region, connected to the electrostatic chuck at one end, and connected to the second separate base of the six-axis platform at the other end; a magnet plate lifting device, which is located in the atmospheric region, connected to the magnet plate at one end, and connected to the second separate base of the six-axis platform at the other end.

[0006] Optionally, the six-axis platform further includes: a three-axis translation and rotation platform, and the three-axis translation and rotation platform is arranged between the first separate base and the second separate base.

[0007] Optionally, with the Cartesian vertical coordinate system as a reference, the motor includes: a plurality of linear displacement motors and a plurality of lifting and lowering stepper motors; wherein, the plurality of linear displacement motors are arranged on the first separate base, each linear displacement motor is connected to a transmission device at a corresponding position, and the linear displacement motor and the transmission device at the corresponding position are used to move the three-axis translation and rotation platform in the horizontal plane direction formed by the X-axis and the Y-axis; the plurality of lifting and lowering stepper motors are arranged between the three-axis translation and rotation platform and the second separate base, each lifting and lowering stepper motor is connected to the transmission device at a corresponding position, and is used to control the pitch angle change of the second separate base in the horizontal plane direction formed by the X-axis and the Y-axis, and control the second separate base to move in the vertical Z direction.

[0008] Optionally, the displacement accuracy range of the linear displacement motor is 10-200nm.

[0009] Optionally, a spherical universal joint is used between the transmission device of the lifting and lowering adjustment stepping motor and the second separate base.

[0010] Optionally, the six-axis platform has a positioning accuracy range of 10-100 nm, a translation range of 100-5000 μm, and an angular accuracy range of ±10 mrad.

[0011] Optionally, a gap sensor is provided on the mask tray for measuring the distance between the substrate to be evaporated and the mask during the alignment process.

[0012] Optionally, the machine vision system includes an alignment camera, which is arranged at a position below the mask tray corresponding to the mask alignment hole, and the pixel resolution range of the alignment camera is 10-100nm.

[0013] Optionally, the vibration protection level of the active isolator is one of VC-C, VC-D or VC-E.

[0014] Optionally, the magnetic field uniformity range of the magnet plate is less than ±10%.

[0015] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0016] The present invention provides an alignment system for a vapor deposition machine. By adopting a high-precision six-axis platform and a vibration isolation system, the interference of the external environment on the high-precision alignment process is avoided, and high-precision alignment between the mask plate and the substrate can be achieved, and even the mask plate and the substrate can be aligned with an accuracy of 0.1μm.

[0017] Furthermore, the vapor deposition machine alignment system provided by the present invention realizes the function of a six-axis platform through two three-axis platforms, which greatly reduces the cost of the vapor deposition machine alignment system while meeting the high-precision alignment between the substrate and the mask plate and the preparation requirements of the Real RGB structure Micro OLED device. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0019] Figure 1 It is a structural schematic diagram of the vapor deposition machine alignment system of the first embodiment of the present invention;

[0020] Figure 2 It is a schematic diagram of the working principle of the vapor deposition machine alignment system according to the first embodiment of the present invention;

[0021] Figure 3 Schematic diagram of the structure of a six-axis platform according to the second embodiment of the present invention. DETAILED DESCRIPTION

[0022] The preferred embodiments of the present invention will be described in more detail below. Although the preferred embodiments of the present invention are described below, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein.

[0023] In the present invention, unless otherwise specified, the directional words used, such as "upper and lower", generally refer to the upper and lower parts of the device in normal use, and "inside and outside" refer to the outline of the device. In addition, the terms "first, second, third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first, second, third" may explicitly or implicitly include one or more of the features. In the description of the present invention, "multiple" means two or more, unless otherwise clearly and specifically defined. In the present invention, it is an electrical device, so connection and interconnection both refer to conductive interconnection. Since the accompanying drawings are descriptions of the same device, the same numbers in the drawings represent the same components.

[0024] As described in the background, in the prior art, the alignment accuracy of the alignment system of a conventional vapor deposition machine is generally 1.5-3 μm, which cannot meet the alignment accuracy requirement of a high-precision coating machine of less than 0.1 μm. Therefore, the present invention provides an alignment system for a vapor deposition machine to solve the above problem.

[0025] The present invention provides an alignment system for an evaporation machine, comprising: a chamber surrounded by a cavity wall, wherein a top plate is arranged in the chamber, wherein the top plate divides the chamber into two parts, wherein the chamber above the top plate is an atmospheric zone, and the chamber below the top plate is a vacuum chamber; a vibration isolation system located in the atmospheric zone, wherein the vibration isolation system comprises two active isolators respectively arranged at two ends of an upper surface of the top plate, for isolating external disturbances; a six-axis platform located in the atmospheric zone, wherein the six-axis platform comprises, from bottom to top, a first separate base, a motor and a second separate base, for controlling the position and posture of a substrate to be evaporated and placed thereon; an alignment device, wherein the alignment device comprises an electrostatic chuck and a mask plate tray arranged in the vacuum chamber, wherein the electrostatic chuck is used to fix the substrate to be evaporated during the alignment process, and wherein the mask plate tray is used to place the mask plate during the alignment process; and a machine vision system, wherein the machine vision system is arranged in the vacuum chamber below the mask plate tray, for real-time detection of the alignment results of the substrate to be evaporated and the mask plate.

[0026] Figure 1-2 The structure and working principle of the vapor deposition machine alignment system of the first embodiment of the present invention are shown. Figure 3 The structural schematic diagram of the six-axis platform of the second embodiment of the present invention is shown. The specific embodiments of the present invention are described below in conjunction with the accompanying drawings. The devices or materials not listed in detail in the embodiments can be selected as any device or material on the market that can realize the corresponding functions, such as the stepper motor can be selected as any stepper motor on the market, and the VC-D level vibration isolator can be any VC-D level vibration isolation platform on the market.

[0027] The present invention provides an evaporator alignment system. Specifically, the evaporator alignment system includes a chamber surrounded by a cavity wall. A top plate 100 is arranged in the chamber. The top plate 100, as a part of the cavity wall, supports and fixes the entire system and divides the chamber into two areas. The chamber above the top plate 100 is an atmospheric zone 200. The components and systems in the atmospheric zone 200 are located in the air; and are protected by a glass protective cover arranged in the atmospheric zone 200; the chamber below the top plate 100 is a vacuum cavity 300. The components and systems at the lower part of the top plate 100 are located in the vacuum cavity 300.

[0028] In the embodiment of the present disclosure, the vibration isolation system is located in the atmospheric zone 200 above the top plate 100, specifically between the top plate 100 and the six-axis platform 103, and includes two active isolators 101 respectively arranged at both ends of the upper surface of the top plate 100, for isolating external disturbances and preventing external shaking from affecting the alignment of the substrate to be evaporated and the mask.

[0029] In some embodiments, the vibration protection level of the active isolator is one of VC-C, VC-D or VC-E.

[0030] In the first embodiment of the present disclosure, the six-axis platform includes, from bottom to top, a first detachable base 102, a motor 103 and a second detachable base 104, which are used to control the position and posture of the substrate to be evaporated placed thereon.

[0031] In the second embodiment of the present disclosure, Figure 3 As shown, the six-axis platform is formed by combining two three-axis platforms, and the six-axis platform includes, from bottom to top: a first separate base 102, four linear displacement motors 130, a three-axis translation and rotation platform 131, three lifting and lowering stepping motors 132 and a second separate base 104. Among them, with the Cartesian vertical coordinate system as a reference, the three-axis translation and rotation platform 131 is connected to the first separate base 102 through four linear displacement motors 130, and the four linear displacement motors 130 have corresponding transmission structures at their respective positions. The three-axis translation and rotation platform 131 is moved in the horizontal plane direction formed by the X-axis and the Y-axis through the four linear displacement motors 130 and their transmission structures installed on the first separate base 102; three lifting and adjusting stepper motors 132 are arranged between the three-axis translation and rotation platform 131 and the first separate base 103, and each lifting and adjusting stepper motor 132 is provided with a corresponding transmission device. Through the three lifting and adjusting stepper motors 132 and their transmission devices, the pitch angle change of the second separate base 104 on the horizontal plane formed by the X-axis and the Y-axis can be controlled, and the second separate base 104 can be controlled to move in the vertical Z direction.

[0032] The second embodiment of the present disclosure realizes the function of a six-axis platform by combining two three-axis platforms. Since the price of this combined platform is much lower than that of a single high-precision six-axis platform, the cost of the system is greatly reduced while meeting the high-precision alignment of 0.1μm.

[0033] In some embodiments, the displacement accuracy range of the linear displacement motor is 10-200 nm, and the transmission device of the lifting and lowering adjustment stepping motor is connected to the second separate base 104 by a spherical universal joint 133 to ensure that the movement of the second separate base is not hindered.

[0034] In some embodiments, the six-axis platform can be a six-axis nano-piezoelectric platform.

[0035] In some embodiments, the six-axis platform has a positioning accuracy range of 10-100 nm, a translation range of 100-5000 μm, and an angular accuracy range of ±10 mrad.

[0036] In the embodiment of the present disclosure, the alignment device includes an electrostatic chuck 112 and a mask plate tray 115 disposed in the vacuum chamber, wherein the electrostatic chuck is used to fix the substrate 120 to be evaporated during the alignment process, and the mask plate tray 115 is used to place the mask plate 122 during the alignment process. A gap sensor 116 is disposed on the mask plate tray 115. When the substrate 120 and the mask plate 122 are aligned, the gap sensor 116 measures the distance between the substrate 120 to be evaporated and the mask plate 122 to avoid the inability to achieve the purpose of evaporation due to the distance between the substrate 120 to be evaporated and the mask plate 122 being too far. A magnet plate 111 is also disposed above the electrostatic chuck 112 in the vacuum chamber, which is used to adsorb the mask plate 122 on the substrate 120 to be evaporated after the alignment is completed.

[0037] In the embodiment of the present disclosure, the alignment device also includes an electrostatic chuck lifting device 105 and a magnet plate lifting device 106 arranged in the atmosphere zone, one end of the electrostatic chuck lifting device 105 is arranged on the second separate base 104, and the other end is connected to the electrostatic chuck 112 arranged in the vacuum chamber, which is used to adjust the position of the substrate to be evaporated during the alignment process; one end of the magnet plate lifting device 106 is arranged on the second separate base 104, and the other end is connected to the magnet plate 111 arranged in the vacuum chamber, which is used to adjust the position of the magnet plate in the vertical direction during the alignment process, thereby realizing the foundation and separation of the mask and the substrate to be evaporated. The position and posture of the substrate to be evaporated 120, the electrostatic chuck 112 and the magnet plate 111 can be finely controlled by the high-precision six-axis platform.

[0038] In some embodiments, the electrostatic chuck lifting device and the magnet plate lifting device are composed of structures such as a stepper motor, a servo motor, a transmission device, and a stabilizer.

[0039] In some embodiments, the magnetic field uniformity of the magnet plate is less than ±10%.

[0040] In some embodiments, the alignment device of the evaporator alignment system also includes a robot for clamping the substrate to be evaporated and the mask plate, which is used to place the substrate to be evaporated and the mask plate into the evaporator before the alignment begins, and to take the substrate to be evaporated and the mask plate out of the evaporator after the alignment is completed.

[0041] In an embodiment of the present disclosure, the vapor deposition machine alignment system includes: a machine vision system arranged below the mask plate tray in the vacuum chamber, the machine vision system includes an alignment camera 117, the alignment camera 117 is arranged below the mask plate tray 115 at a position corresponding to the mask plate alignment hole 121, the pixel resolution range of the alignment camera 117 is 10-100nm, and it is used to perform real-time detection of the alignment results of the vapor deposition substrate 120 and the mask plate 122.

[0042] In the disclosed embodiment, specifically, when the substrate 120 to be evaporated and the mask 122 are aligned, first, the substrate 120 to be evaporated is transported from the outside or the storage cavity to the position between the electrostatic chuck 112 and the mask tray 115 by the substrate transport robot 113. The electrostatic chuck 112 is driven by the electrostatic chuck lifting device 105 to contact the substrate 120 to be evaporated and the electrostatic generator is turned on, and the substrate 120 to be evaporated is adsorbed on the lower surface of the electrostatic chuck 112 by electrostatic adsorption. The electrostatic chuck rises, and the substrate transport robot 113 is withdrawn. The mask is transported from the outside or the storage cavity to the position between the electrostatic chuck 112 and the mask tray 115 by the mask transport robot 114, and the height of the mask tray 115 is raised to support the mask, and the mask transport robot is withdrawn, and the mask is fixed by the mask clamping device, and then the substrate to be evaporated and the mask are aligned.

[0043] In order to keep the vapor deposition machine alignment system from being affected by external vibrations, the electrostatic suction cup 112 used to adsorb the substrate to be evaporated and the magnet plate 111 used to adsorb the mask are installed on the first separate base 102 through a lifting device. The first separate base 102 is installed on the top plate 100 through an active vibrator with a vibration resistance grade of VC-D.

[0044] Afterwards, the position and parameters of the alignment camera 117 are adjusted so that its field of view is directly opposite to the vapor deposition alignment holes 124 on the mask plate film 122 and the mask plate frame 123. The field of view (FOV) is generally set to 0.5mm×0.5mm, the depth of field is 60μm, and the pixel resolution is 90nm. The electrostatic chuck 112 carrying the substrate to be evaporated 120 is lowered to a distance of about 1μm from the mask plate and stopped by the electrostatic chuck lifting device 105. This distance is measured by the gap sensor 116. At this time, the image of the mask plate alignment hole 124 and the substrate can be clearly presented in the field of view of the alignment camera 117. Under the monitoring of the alignment camera, the three-dimensional position and three-dimensional rotation and inclination parameters of the substrate to be evaporated 120 are adjusted through the six-axis platform so that the alignment mark 121 of the substrate to be evaporated is accurately aligned with the mask plate alignment hole 124. The alignment camera 117 can achieve a positioning accuracy of 1 pixel through machine vision and machine learning algorithms, that is, the alignment system of the present invention can achieve a high-precision alignment of 90nm between the substrate to be evaporated and the mask. After the alignment is completed, the mask tray 115 is lifted to make the mask fit tightly with the substrate to be evaporated. The alignment camera detects the alignment mark of the substrate to be evaporated and the position of the alignment hole of the mask to determine the alignment of the substrate to be evaporated and the mask after bonding. If the alignment of the two is offset after bonding and exceeds the alignment requirement of 0.1μm, the mask is lowered, re-aligned and bonded again until the alignment of the bonded mask and the substrate to be evaporated meets the requirement of 0.1μm.

[0045] In the vapor deposition machine alignment system of the present invention, the mask plate used for vapor deposition is placed in the mask plate tray 115 fixed under the top plate, and the position and posture of the substrate to be vapor deposited 120 adsorbed on the electrostatic chuck 112 are adjusted to achieve the purpose of high-precision alignment between the substrate and the mask plate. Through the above operation steps, the vapor deposition machine alignment system of the present invention can achieve 0.1μm (3σ) precision alignment between the substrate and the mask plate, meeting the preparation requirements of Real RGB structure Micro OLED devices.

[0046] The above descriptions are merely embodiments of the present application and are not intended to limit the patent scope of the present application. Any equivalent structural or equivalent process transformations made using the contents of the specification and drawings of the present application, such as the mutual combination of technical features between the embodiments, or direct or indirect application in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A vapor deposition machine alignment system, characterized in that: include: A chamber surrounded by a cavity wall, wherein a top plate is arranged in the chamber, and the top plate divides the chamber into two parts, the chamber above the top plate is an atmospheric area, and the chamber below the top plate is a vacuum chamber; A vibration isolation system located in the atmospheric zone, the vibration isolation system comprising two active isolators respectively arranged at two ends of the upper surface of the top plate, for isolating external disturbances; A six-axis platform located in the atmosphere zone, the six-axis platform comprising, from bottom to top, a first detachable base, a motor and a second detachable base, for controlling the position and posture of a substrate to be evaporated placed thereon; An alignment device, the alignment device comprising an electrostatic chuck and a mask tray disposed in the vacuum chamber, the electrostatic chuck being used to fix the substrate to be evaporated during the alignment process, and the mask tray being used to place the mask during the alignment process; A machine vision system is arranged in a vacuum chamber below the mask plate tray and is used for real-time detection of the alignment results of the substrate to be evaporated and the mask plate.

2. The vapor deposition machine alignment system according to claim 1, characterized in that: The alignment system also includes: A magnet plate, which is located in the vacuum chamber and is used to adsorb the mask onto the substrate to be evaporated; An electrostatic chuck lifting device, wherein the electrostatic chuck lifting device is located in the atmospheric region, one end of the electrostatic chuck is connected to the electrostatic chuck, and the other end of the electrostatic chuck is connected to the second separate base of the six-axis platform; A magnet plate lifting device is located in the atmospheric region, one end of the magnet plate is connected to the magnet plate, and the other end is connected to the second separate base of the six-axis platform.

3. The vapor deposition machine alignment system according to claim 2, characterized in that: The six-axis platform further includes: a three-axis translation and rotation platform, and the three-axis translation and rotation platform is arranged between the first separate base and the second separate base.

4. The vapor deposition machine alignment system according to claim 3, characterized in that: Taking the Cartesian vertical coordinate system as a reference, the motor includes: a plurality of linear displacement motors and a plurality of lifting and lowering adjustment stepping motors; wherein, A plurality of linear displacement motors are arranged on the first separate base, each of which is connected to a transmission device at a corresponding position, and the linear displacement motors and the transmission device at the corresponding position are used to move the three-axis translation and rotation platform in the horizontal plane direction formed by the X-axis and the Y-axis; a plurality of lifting and lowering stepper motors are arranged between the three-axis translation and rotation platform and the second separate base, each of which is connected to a transmission device at a corresponding position, and is used to control the pitch angle change of the second separate base in the horizontal plane direction formed by the X-axis and the Y-axis, and to control the second separate base to move in the vertical Z direction.

5. The vapor deposition machine alignment system according to claim 4, characterized in that: The displacement accuracy of the linear displacement motor is in the range of 10-200 nm.

6. The vapor deposition machine alignment system according to claim 4, characterized in that: The transmission device of the lifting and lowering regulating stepping motor is connected to the second separate base by a spherical universal joint.

7. The vapor deposition machine alignment system according to any one of claims 1 to 6, characterized in that: The positioning accuracy of the six-axis platform is in the range of 10-100 nm, the translation range is 100-5000 μm, and the angular accuracy range is ±10 mrad.

8. The vapor deposition machine alignment system according to claim 1, characterized in that: The mask plate tray is provided with a gap sensor for measuring the distance between the substrate to be evaporated and the mask plate during the alignment process.

9. The vapor deposition machine alignment system according to claim 1, characterized in that: The machine vision system comprises an alignment camera, which is arranged at a position below the mask plate tray corresponding to the mask plate alignment hole, and the pixel resolution range of the alignment camera is 10-100nm.

10. The vapor deposition machine alignment system according to claim 1, characterized in that: The vibration protection grade of the active isolator is one of VC-C, VC-D or VC-E.

11. The vapor deposition machine alignment system according to claim 2, characterized in that: The magnetic field uniformity range of the magnet plate is less than ±10%.

Images