Alignment system and method

Abstract

The invention discloses an alignment system and method which can be applied to the technical field of semiconductors, and the system comprises an equipment front-end module and a processing module. The equipment front-end module comprises a mechanical arm, a first pre-alignment device and a second pre-alignment device; during wafer taking, the mechanical arm is used for carrying the wafer from the wafer box to the first pre-alignment device and carrying the tray from the tray box to the second pre-alignment device; the first pre-alignment device is used for pre-aligning the wafer; the second pre-alignment device is used for pre-aligning the tray; the mechanical arm is further used for carrying the pre-aligned wafer to the position above the pre-aligned tray, and the wafer is placed into the tray through the second pre-alignment device; the mechanical arm is also used for carrying the tray carrying the wafer to the processing module; the processing module is used for receiving the tray and processing the wafer carried by the tray. Therefore, the wafer and the tray are pre-aligned through the two pre-alignment devices respectively, the carrying frequency is reduced, and the pre-alignment precision is improved.

Description

Technical Field

[0001] The present application relates to the field of semiconductor technology, and in particular to an alignment system and method. Background Art

[0002] In high-temperature processes such as wafer CVD (chemical vapor deposition) and annealing, the discontinuity between the wafer edge and the surrounding medium can easily lead to inconsistent heating between the wafer edge and the inside of the wafer, which in turn causes the wafer to warp and reduce product yield. Therefore, the industry often uses trays to carry wafers, and places the trays and wafers together in the process chamber for high-temperature processes.

[0003] If wafers are manually loaded into trays and then the trays carrying the wafers are placed into the process chamber, it is difficult to ensure cleanliness and production efficiency. Therefore, an automatic alignment system is introduced, but the existing automatic alignment system usually uses a pre-alignment device combined with a buffer area structure. The alignment process involves multiple wafer and tray handling, which can easily cause the pre-aligned wafers or trays to shift again, resulting in low pre-alignment accuracy.

[0004] Therefore, how to improve the accuracy of pre-alignment is a problem that technical personnel in this field need to solve urgently. Summary of the invention

[0005] Based on the above problems, the present application provides an alignment system and method, which pre-aligns the wafer and the tray respectively through two pre-alignment devices, thereby reducing the number of transport times and improving the pre-alignment accuracy.

[0006] In a first aspect, an embodiment of the present application provides an alignment system, including: a device front-end module and a process module;

[0007] The equipment front-end module includes a mechanical arm, a first pre-alignment device and a second pre-alignment device;

[0008] When taking out a wafer, the robot arm is used to move the wafer from the wafer box to the first pre-alignment device, and move the tray from the tray box to the second pre-alignment device;

[0009] The first pre-alignment device is used to pre-align the wafer;

[0010] The second pre-alignment device is used to pre-align the tray;

[0011] The robot arm is also used to carry the pre-aligned wafer to the top of the pre-aligned tray, and the second pre-alignment device places the wafer into the tray;

[0012] The robot arm is also used to transport the tray carrying the wafer to the process module; the process module is used to receive the tray and perform processing on the wafer carried by the tray.

[0013] Optionally, the first pre-alignment device includes: a first linear sensor, a first lifting assembly and a first rotating platform;

[0014] The first lifting assembly is used to dock with the robotic arm when it is lifted, and receive the wafer carried by the robotic arm;

[0015] The first lifting assembly is used to dock with the first rotating platform when it is lowered, so as to place the wafer on the first rotating platform;

[0016] The first rotating platform is used to fix the wafer and drive the wafer to rotate;

[0017] The first linear sensor includes a first receiving end and a first transmitting end, the first transmitting end is used to generate a first linear light emitted to the first receiving end; the first receiving end is used to receive the first linear light blocked by the rotating wafer, and determine the center of the wafer based on photoelectric conversion;

[0018] The first lifting assembly is also used to move the wafer after centering, and to align the center of the wafer with the first rotating platform;

[0019] The first rotating platform is also used to perform flat edge alignment on the center-aligned wafer.

[0020] Optionally, the first linear light has a specific length, is partially blocked by the wafer fixed on the first rotating platform, and the first linear light is perpendicular to both the wafer and the first receiving end.

[0021] Optionally, the first lifting assembly includes at least three first lifting columns, and each of the first lifting columns is connected in sequence as a vertex to form a polygon.

[0022] Optionally, all of the first lifting columns are connected to the same movement control assembly;

[0023] The movement control assembly is used to control each of the first lifting columns to move in the same direction.

[0024] Optionally, the second pre-alignment device comprises: a second linear sensor, a second lifting assembly and a second rotating platform;

[0025] During the pre-alignment process of the pallet, the second lifting assembly is used to dock with the robotic arm when it is raised, and receive the pallet carried by the robotic arm;

[0026] The second lifting assembly is used to dock with the second rotating platform when it is lowered, so as to place the tray on the second rotating platform;

[0027] The second rotating platform is used to fix the tray and drive the tray to rotate;

[0028] The second linear sensor includes a second receiving end and a second transmitting end, the second transmitting end is used to generate a second linear light emitted to the second receiving end; the second receiving end is used to receive the second linear light blocked by the rotating tray, and determine the center of the tray based on photoelectric conversion;

[0029] The second lifting assembly is also used to move the tray after the center is determined, and to align the center of the tray with the second rotating platform;

[0030] The second rotating platform is also used to align the center-aligned tray with flat edges.

[0031] Optionally, the second linear light has a specific length, is partially blocked by the tray fixed on the second rotating platform, and the second linear light is perpendicular to both the tray and the second receiving end.

[0032] Optionally, the second lifting assembly includes at least three second lifting columns, and each of the second lifting columns is connected in sequence as a vertex to form a polygon.

[0033] Optionally, all of the second lifting columns are connected to the same movement control assembly;

[0034] The movement control assembly is used to control each of the second lifting columns to move in the same direction.

[0035] Optionally, a groove for placing the wafer is provided on the upper surface of the tray, and the depth of the groove is the same as the thickness of the wafer;

[0036] The inner surface of the tray is provided with a limiting block corresponding to the flat edge of the wafer, so as to limit the rotation of the wafer relative to the tray.

[0037] Optionally, the tray is provided with through holes whose number matches the number of the second lifting columns, and a figure formed by sequentially connecting the through holes is consistent with a polygon formed by sequentially connecting the second lifting columns as vertices;

[0038] When the tray is placed on the second rotating platform by the second lifting column, a figure formed by sequentially connecting the through holes and a polygon formed by sequentially connecting the through holes with the second lifting column as a vertex form a specific angle;

[0039] When the pre-alignment of the pallet is completed, the second rotating platform rotates the pallet counterclockwise by a specific angle to align the through hole of the pallet with the second lifting column so that the second lifting column can pass through the through hole when it is raised without lifting the pallet.

[0040] Optionally, the number of the second lifting components and the number of the through holes are both four;

[0041] The figure formed by the four through holes connected in sequence and the polygon formed by the four second lifting columns as vertices connected in sequence are both rectangles; when the tray is placed on the second rotating platform by the second lifting columns, the long sides of the rectangle formed by the through holes connected in sequence and the long sides of the rectangle formed by the second lifting columns as vertices connected in sequence are perpendicular to each other;

[0042] When the pre-alignment of the pallet is completed, the second rotating platform rotates the pallet counterclockwise by 90° to align the through hole of the pallet with the second lifting column so that the second lifting column can pass through the through hole when it is raised without lifting the pallet.

[0043] Optionally, after the tray is rotated counterclockwise by 90°, the flat edge of the tray is consistent with the flat edge angle of the wafer after pre-alignment.

[0044] Optionally, when placing the wafer, the robot arm is used to move the tray carrying the wafer from the process module to the second pre-alignment device;

[0045] The second pre-alignment device is used to pre-align the tray carrying the wafer;

[0046] The robot arm is also used to transport the wafer on the pre-aligned tray to the wafer box, and to transport the tray to the tray box.

[0047] In a second aspect, an embodiment of the present application provides an alignment method in a film picking process, the method being applied to the alignment system as described above, comprising:

[0048] Using a robotic arm to obtain a wafer from a wafer box and transport it to a first pre-alignment device for pre-alignment;

[0049] Using a robotic arm to obtain a tray from a tray box, and transporting it to a second pre-alignment device for pre-alignment; the flat edge of the wafer after pre-alignment and the flat edge of the tray after pre-alignment have the same angle;

[0050] Using a robot arm to move the pre-aligned wafer to above the tray, and using the second pre-alignment device to place the wafer into the tray;

[0051] The tray loaded with the wafers is transported to a process module by a robotic arm and processed.

[0052] In a third aspect, an embodiment of the present application provides an alignment method during a wafer placement process, the method being applied to the alignment system as described above, comprising:

[0053] Using a robotic arm to obtain the tray carrying the wafer after the process is completed from the process module, and transport it to the second pre-alignment device;

[0054] Pre-aligning the tray carrying the wafer using a second pre-alignment device;

[0055] The wafer on the pre-aligned tray is transported to a wafer box by a robot arm, and the tray is transported to a tray box.

[0056] It can be seen from the above technical solutions that compared with the prior art, the present application has the following advantages:

[0057] The present application provides an alignment system and method, the system includes: a device front-end module and a process module; the device front-end module includes a robotic arm, a first pre-alignment device and a second pre-alignment device; when taking a wafer, the robotic arm is used to transport the wafer from the wafer box to the first pre-alignment device, and transport the tray from the tray box to the second pre-alignment device; the first pre-alignment device is used to pre-align the wafer; the second pre-alignment device is used to pre-align the tray; the robotic arm is also used to transport the pre-aligned wafer to the top of the pre-aligned tray, and the second pre-alignment device puts the wafer into the tray; the robotic arm is also used to transport the tray carrying the wafer to the process module; the process module is used to receive the tray and process the wafer carried by the tray. Thus, the wafer and the tray are pre-aligned respectively by two pre-alignment devices, which reduces the number of transports and improves the pre-alignment accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Figure 1 A schematic diagram of the structure of an alignment system provided in an embodiment of the present application;

[0059] Figure 2 A schematic structural diagram of a first pre-alignment device provided in an embodiment of the present application;

[0060] Figure 3 A schematic diagram of the structure of a first lifting assembly provided in an embodiment of the present application;

[0061] Figure 4 A schematic diagram of a loading port arrangement provided in this application;

[0062] Figure 5 A schematic diagram of the structure of an end effector provided in this application;

[0063] Figure 6 A schematic structural diagram of a second pre-alignment device provided in the present application;

[0064] Figure 7 A structural schematic diagram of a second lifting assembly provided in this application;

[0065] Figure 8 A schematic diagram of the structure of a tray provided in an embodiment of the present application;

[0066] Fig. 9 A schematic diagram of a through-hole alignment method provided in an embodiment of the present application;

[0067] Fig.10 A flowchart of an alignment method in a film taking process provided by an embodiment of the present application;

[0068] Fig.11 A schematic diagram of a wafer pre-alignment process provided in an embodiment of the present application;

[0069] Fig.12 A schematic diagram of a tray pre-alignment process provided in an embodiment of the present application;

[0070] Fig.13 A flowchart of a combination method provided for an embodiment of the present application;

[0071] Fig.14 A schematic diagram of a process for transporting a tray carrying wafers to a process module provided in an embodiment of the present application;

[0072] Fig.15 A flowchart of an alignment method during a film placement process provided in an embodiment of the present application. DETAILED DESCRIPTION

[0073] As mentioned above, the existing alignment system has the problem of low pre-alignment accuracy. Specifically, the existing automatic alignment system usually adopts a pre-alignment device combined with a buffer area structure. Generally, the tray is first pre-aligned on the pre-alignment device, and then the tray is moved to the buffer area after completion. The wafer is then transported to the pre-alignment device for pre-alignment, and after completion, the wafer is moved to the tray in the buffer area for assembly. Finally, the tray carrying the wafer is moved from the buffer area to the process chamber. The entire alignment process involves multiple wafer and tray transports. Since the robotic arm mostly uses vacuum suction to transport wafers and trays, it is easy for the pre-aligned wafers or trays to shift again during the process of taking and placing, resulting in the problem of low pre-alignment accuracy.

[0074] To solve the above problems, an embodiment of the present application provides an alignment system, including: an equipment front-end module and a process module; the equipment front-end module includes a robotic arm, a first pre-alignment device and a second pre-alignment device; when taking a wafer, the robotic arm is used to transport the wafer from the wafer box to the first pre-alignment device, and transport the tray from the tray box to the second pre-alignment device; the first pre-alignment device is used to pre-align the wafer; the second pre-alignment device is used to pre-align the tray; the robotic arm is also used to transport the pre-aligned wafer to the top of the pre-aligned tray, and the second pre-alignment device places the wafer into the tray; the robotic arm is also used to transport the tray carrying the wafer to the process module; the process module is used to receive the tray and perform processes on the wafer carried by the tray.

[0075] Thus, the wafer and the tray are pre-aligned respectively by two pre-alignment devices, which reduces the number of transports and improves the pre-alignment accuracy.

[0076] It should be noted that the alignment system and method provided by the present application can be applied to the field of semiconductor technology. The above is only an example and does not limit the application field of the alignment system and method provided by the present application.

[0077] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0078] Figure 1 A schematic diagram of the structure of an alignment system provided in an embodiment of the present application. Figure 1 As shown, an alignment system provided by an embodiment of the present application includes: a device front-end module 101 and a process module 102;

[0079] The equipment front-end module 101 includes a mechanical arm 201, a first pre-alignment device 202 and a second pre-alignment device 203;

[0080] When taking out a wafer, the robot arm 201 is used to move the wafer from the wafer box to the first pre-alignment device 202, and to move the tray from the tray box to the second pre-alignment device 203;

[0081] The first pre-alignment device 202 is used to pre-align the wafer;

[0082] The second pre-alignment device 203 is used to pre-align the tray;

[0083] The robot arm 201 is also used to carry the pre-aligned wafer to the top of the pre-aligned tray, and the second pre-alignment device 203 places the wafer into the tray;

[0084] The robot arm 201 is further used to transport the tray carrying the wafers to the process module 102; the process module 102 is used to receive the tray and perform processes on the wafers carried by the tray.

[0085] The present application provides an alignment system, which is composed of an equipment front-end module 101 (Equipment Front-End Module, EFEM) and a process module 102PM. The equipment front-end module 101 is used to perform preparatory work before the process, such as wafer alignment, tray alignment, and the combination of wafer and tray, and the process module 102 is used to receive the tray carrying the wafer and perform processes, such as annealing and high-temperature operations such as CVD. In the equipment front-end module 101, the embodiment of the present application provides a structure in which a robotic arm 201 cooperates with a dual pre-alignment device (a first pre-alignment device 202 and a second pre-alignment device 203), and pre-aligns the wafer and the tray respectively through independent devices, thereby reducing the number of transports and improving the alignment accuracy. Specifically, a first pre-alignment device 202 corresponding to the wafer and a second pre-alignment device 203 corresponding to the tray can be set on the right side of the EFEM, and the robotic arm 201 is set in the cavity of the EFEM. When taking out the wafer for processing, the robot arm 201 first moves the wafer from the wafer box to the first pre-alignment device 202, and the first pre-alignment device 202 pre-aligns the wafer. Then the robot arm 201 moves the tray from the tray box to the second pre-alignment device 203, and the second pre-alignment device 203 pre-aligns the tray. It should be noted that the pre-aligned wafer and tray need to meet two points, one is the center alignment, and the other is that the angle of the wafer is consistent with the flat edge or notch (notch / flat) of the tray. Then, the robot arm 201 moves the pre-aligned wafer to the pre-aligned tray, combines it through the second pre-alignment device 203, and moves the assembled tray carrying the wafer to the process module 102 for processing.

[0086] As an implementation manner, regarding how to set the first pre-alignment device 202, correspondingly, the first pre-alignment device 202 includes: a first linear sensor 301, a first lifting assembly 302 and a first rotating platform 303;

[0087] The first lifting assembly 302 is used to dock with the robotic arm 201 when it is lifted, and receive the wafer carried by the robotic arm 201;

[0088] The first lifting assembly 302 is used to dock with the first rotating platform 303 when it is lowered, so as to place the wafer on the first rotating platform 303;

[0089] The first rotating platform 303 is used to fix the wafer and drive the wafer to rotate;

[0090] The first linear sensor 301 includes a first receiving end and a first transmitting end, wherein the first transmitting end is used to generate a first linear light directed toward the first receiving end; the first receiving end is used to receive the first linear light blocked by the rotating wafer, and determine the center of the wafer based on photoelectric conversion;

[0091] The first lifting assembly 302 is also used to move the wafer after centering, and to align the wafer with the first rotating platform 303;

[0092] The first rotating platform 303 is also used to perform flat edge alignment on the center-aligned wafer.

[0093] Figure 2 A schematic diagram of the structure of a first pre-alignment device provided in an embodiment of the present application. Figure 2 As shown, (a) is a side view, and (b) is a top view. The first lifting assembly 302 has a lifting function. When taking a wafer, it rises and docks with the robot arm 201 (the docking height of the first lifting assembly 302 is higher than the upper surface height of the first rotating platform 303). The robot arm 201 transports the wafer to the top of the first pre-alignment device 202 and slowly lowers it to the raised first lifting assembly 302. Then, the first lifting assembly 302 descends and docks with the first rotating platform 303, placing the wafer on the first rotating platform 303. After receiving the wafer, the first rotating platform 303 performs a vacuum suction action to fix the wafer and drive the wafer to rotate. The first linear sensor 301 includes a first receiving end and a first transmitting end, wherein the first transmitting end can generate a first linear light 301A directed to the first receiving end. When the wafer is placed on the first rotating platform 303, the first linear light 301A will be partially blocked, and the blocking area will change as the wafer rotates. The first receiving end is located directly below the first linear light 301A, and can receive the first linear light 301A blocked by the rotating wafer, and based on photoelectric conversion, a voltage waveform similar to a sine wave is formed, and the center and flat edge position of the wafer can be determined by calculation. In addition, the first lifting assembly 302 also has a moving function. After determining the center of the wafer, the first rotating platform 303 breaks the vacuum, and the first lifting assembly 302 lifts and moves the wafer, aligns the center of the wafer with the center of the first rotating platform 303, and then puts it down to achieve center alignment of the wafer. Then, the first rotating platform 303 fixes the wafer and rotates the flat edge of the wafer to a preset angle.

[0094] It should be noted that the first linear light 301A in the embodiment of the present application is set to have a specific length (generally 0-10 mm, which can be linearly converted into an analog voltage of 0-5 V), so that the wafer fixed on the first rotating platform 303 can partially block the first linear light 301A (generally, the wafer after center alignment can block half of the length of the first linear light 301A), and the first linear light 301A is perpendicular to the wafer and the first receiving end. It can be understood that in order to facilitate calculation, the first linear light 301A is set to irradiate the wafer surface and the first receiving end surface vertically.

[0095] As an implementation manner, regarding how to set the first lifting assembly 302, the first lifting assembly 302 includes at least three first lifting columns 401, and the first lifting columns 401 are sequentially connected as vertices to form a polygon.

[0096] Specifically, the area of ​​the upper surface of a single first lifting column 401 is very small. When placing a wafer on the first lifting column 401, if it is not possible to ensure that the center of the upper surface of the first lifting column 401 corresponds to the center of the wafer, the wafer cannot be placed successfully. Even if the centers of the two are placed successfully, the wafer can easily fall off when the first lifting column 401 drives the wafer to move up and down. It is understandable that only two first lifting columns 401 are set, because the line connecting their vertices is a straight line, so there is also such a problem. For this reason, the embodiment of the present application requires that at least three first lifting columns 401 be set, and their connecting lines cannot be on the same straight line, that is, each first lifting column 401 is connected in sequence as a vertex to form a triangle, so as to improve the stability of the wafer when it is placed on the first lifting column 401, so that it is not easy to fall.

[0097] In addition, as an implementation manner, with respect to how to set the number of the first lifting columns 401 , the first lifting assembly 302 accordingly includes four first lifting columns 401 , and the four first lifting columns 401 are sequentially connected as vertices to form a rectangle.

[0098] Figure 3 A schematic diagram of the structure of a first lifting assembly provided in an embodiment of the present application. Figure 3 As shown, the first lifting assembly 302 provided in the embodiment of the present application is composed of four first lifting pins 401, and a rectangle can be obtained by connecting the four first lifting pins 401 as vertices in sequence.

[0099] It should be noted that if the long side of the rectangle is defined as the X-axis and the short side is defined as the Y-axis, combined with Figure 3As shown, the first lifting assembly 302 in the embodiment of the present application is also provided with a limit groove, and the four first lifting columns 401 are connected to the same movement control assembly, and the movement control assembly can control the four first lifting columns 401 to move in the X-axis (long side of the rectangle) direction at the same time. It can be understood that the upper limit of the moving distance will be higher when moving along the long side than when moving along the short side, thereby being able to better achieve the center alignment of the wafer. Specifically, Figure 3 Take the provided limiting groove as an example, which limits the up and down displacement of the first lifting column 401, and leaves space on the left and right sides, so that the first lifting column 401 can move along the X-axis direction, and by increasing the space left on both sides of the limiting groove, the upper limit of the movement value of the first lifting column 401 can be increased, until the two limiting grooves overlap and reach the maximum critical value. Similarly, the limiting groove can be rotated 90° clockwise to set the first lifting column 401 to move up and down. The difference is that since the long side of the rectangle is longer than the short side, in order to avoid the overlap of the two limiting grooves, the upper limit of the space left on both sides of the limiting groove set on the long side must be greater than the limiting groove set on the short side. Therefore, the embodiment of the present application controls the four first lifting columns 401 to move in the X-axis (long side of the rectangle) direction at the same time, so that the limiting groove is more convenient to set, and the success rate of the center alignment of the wafer is improved.

[0100] As an implementation method, with respect to how to set the components of the alignment system, the alignment system accordingly further includes: a wafer loading port 204 and a tray loading port 205;

[0101] The wafer loading port 204 is used to place the wafer box and to open the wafer box when taking wafers;

[0102] The tray loading port 205 is used to place the tray box and to open the tray box when taking out the sheets.

[0103] Figure 4 A schematic diagram of a loading port configuration provided in an embodiment of the present application. Figure 4 As shown, two types of loading ports are set at the front end of the EFEM, the left side of the front end is a wafer loading port 204, and the right side of the front end is a tray loading port 205. The wafer loading port 204 is provided with a slot, which is used in conjunction with the slot at the bottom of the wafer box 206. The wafer box 206 can be fixed on the wafer loading port 204 through the slot, and the wafer box 206 is placed with wafers with adjusted flat edges; the tray loading port is also provided with a slot, which is used in conjunction with the slot at the bottom of the tray box 207. The tray box 207 can be fixed on the tray loading port 205 through the slot, and the tray box 207 is placed with trays with adjusted flat edges and the number corresponding to the wafers. When taking out the wafers, the wafer loading port 204 and the tray loading port 205 can open the wafer box 206 and the tray box 207 respectively.

[0104] As an implementation method, regarding how to set the robot arm 201, the robot arm 201 includes a central axis 208 and an end effector 209;

[0105] The central shaft 208 is used to drive the end effector 209 to move;

[0106] The end effector 209 is used to carry and transport the wafer and / or the tray.

[0107] Continue to combine Figure 4 As shown, the robot arm 201 provided in the embodiment of the present application includes a central axis 208 and an end effector 209. The carrying capacity of the end effector 209 is set to be compatible with carrying wafers, trays, and a combination of wafers and trays. Figure 5 A schematic diagram of the structure of an end effector provided in an embodiment of the present application. Figure 5 As shown, (a) is a top view, and (b) is a side view. The width of the end effector 209 is set to be able to extend from the middle of the two first lifting columns 401 on the short side, and the thickness is set to be able to extend into the space between the bottom of the wafer and the top of the first rotating platform 303 when the first lifting columns 401 lift the wafer to the highest point, and a certain safety margin space is maintained between the end effector 209 and the bottom of the wafer and the top of the first rotating platform 303.

[0108] As an implementation manner, regarding how to set the second pre-alignment device 203, correspondingly, the second pre-alignment device 203 includes: a second linear sensor 304, a second lifting assembly 305 and a second rotating platform 306;

[0109] During the pre-alignment process of the pallet, the second lifting assembly 305 is used to dock with the robotic arm 201 when it is raised, and receive the pallet carried by the robotic arm 201;

[0110] The second lifting assembly 305 is used to dock with the second rotating platform 306 when it is lowered, so as to place the tray on the second rotating platform 306;

[0111] The second rotating platform 306 is used to fix the tray and drive the tray to rotate;

[0112] The second linear sensor 304 includes a second receiving end and a second transmitting end, wherein the second transmitting end is used to generate a second linear light emitted to the second receiving end; the second receiving end is used to receive the second linear light blocked by the rotating tray and determine the center of the tray based on photoelectric conversion;

[0113] The second lifting assembly 305 is also used to move the tray after the center is determined, and to align the center of the tray with the second rotating platform 306;

[0114] The second rotating platform 306 is also used to align the center-aligned tray for flat edges.

[0115] Figure 6 A schematic diagram of the structure of a second pre-alignment device provided in an embodiment of the present application. Figure 6 As shown, (a) is a side view, and (b) is a top view. The second pre-alignment device 203 is set in the same manner as the first pre-alignment device 202. The second lifting assembly 305 has a lifting function. When taking a wafer, it rises and docks with the robot arm 201 (the docking height of the second lifting assembly 305 is higher than the upper surface height of the second rotating platform 306). The robot arm 201 first transports the tray to the top of the second pre-alignment device 203 and slowly lowers it to the raised second lifting assembly 305. Then, the second lifting assembly 305 descends and docks with the second rotating platform 306, placing the tray on the second rotating platform 306. After receiving the tray, the second rotating platform 306 performs a vacuum suction action to fix the tray and drive the tray to rotate. The second linear sensor 304 includes a second receiving end and a second transmitting end, wherein the second transmitting end can generate a second linear light 304A directed to the second receiving end. When the tray is placed on the second rotating platform 306, the second linear light 304A will be partially blocked, and the blocking area will change as the wafer rotates. The second receiving end is located directly below the second linear light 304A, and can receive the second linear light 304A blocked by the rotating tray, and based on photoelectric conversion, a voltage waveform similar to a sine type is formed, and the center and flat edge position of the tray can be determined by calculation. In addition, the second lifting component 305 also has a moving function. After determining the center of the tray, the second rotating platform 306 breaks the vacuum, and the second lifting component 305 lifts and moves the tray, aligns the center of the tray with the center of the second rotating platform 306, and then puts it down to achieve the center alignment of the tray. Then, the second rotating platform 306 fixes the tray and rotates the flat edge of the tray to a preset angle.

[0116] It should be noted that the second linear light 304A in the embodiment of the present application is the same as the first linear light 301A, and is set to have a specific length (generally 0-10 mm, which can correspond to the linear conversion of 0-5V analog voltage), and also satisfies that the tray fixed on the second rotating platform 306 can partially block the second linear light 304A (generally, the tray after center alignment can block half of the length of the second linear light 304A), and the second linear light 304A is perpendicular to both the tray and the second receiving end. It can be understood that for the convenience of calculation, the second linear light 304A is set to irradiate the tray surface and the second receiving end surface perpendicularly.

[0117] As an implementation manner, regarding how to set the second lifting assembly 305, correspondingly, the second lifting assembly 305 includes at least three second lifting columns 402, and each of the second lifting columns 402 is sequentially connected as a vertex to form a polygon.

[0118] Specifically, the purpose of setting the first lifting column 401 is the same as that of the upper surface of a single second lifting column 402. The area of ​​the upper surface of a single second lifting column 402 is very small. When placing a tray / or wafer on the second lifting column 402, if it is not possible to ensure that the center of the upper surface of the second lifting column 402 corresponds to the center of the tray, the placement cannot be successful. Even if the centers of the two are placed successfully, the second lifting column 402 can easily cause the wafer to fall off when the tray / or wafer is driven up and down. It is understandable that only two second lifting columns 402 are set, because the line connecting their vertices is a straight line, so there is also such a problem. For this reason, the embodiment of the present application requires that at least three second lifting columns 402 be set, and their connecting lines cannot be on the same straight line, that is, each second lifting column 402 is connected in sequence as a vertex to form a triangle, so as to improve the stability of the tray / or wafer when it is placed on the second lifting column 402, so that it is not easy to fall. As an implementation manner, with respect to how to set the number of the second lifting columns 402 , the second lifting assembly 305 accordingly includes four second lifting columns 402 , and the four second lifting columns 402 are sequentially connected as vertices to form a rectangle.

[0119] Figure 7 A schematic diagram of the structure of a second lifting assembly provided in an embodiment of the present application. Figure 7 As shown, the second lifting assembly 305 is arranged in the same manner as the first lifting assembly 302, and is composed of four second lifting pins 402. The four second lifting pins 402 are connected in sequence as vertices to form a rectangle.

[0120] It should be noted that if the long side of the rectangle is defined as the X-axis and the short side is defined as the Y-axis, combined with Figure 7 As shown, the second lifting assembly 305 in the embodiment of the present application is also provided with a limit groove, and the four second lifting columns 402 are connected to the same mobile control assembly. The mobile control assembly can control the four second lifting columns 402 to move in the X-axis (the long side of the rectangle) direction at the same time, so as to more conveniently set the limit groove and improve the success rate of the center alignment of the wafer.

[0121] As an example, four second lifting columns 402 are provided to illustrate how to design a tray. Accordingly, the tray is made of silicon carbide or alumina ceramics.

[0122] The upper surface of the tray is provided with a groove for placing the wafer, and the depth of the groove is the same as the thickness of the wafer;

[0123] A limit block corresponding to the flat edge of the wafer is provided on the inner surface of the tray, so as to limit the rotation of the wafer relative to the tray;

[0124] The tray is provided with four through holes matching the second lifting columns 402 .

[0125] Figure 8 A schematic diagram of the structure of a tray provided in an embodiment of the present application. Figure 8 As shown, in order to meet the process requirements, the tray can be made of silicon carbide (SIC) or alumina ceramics, and a groove slightly larger than the outer diameter of the wafer is set on its upper surface. The depth can achieve that after the wafer is placed in the groove, the upper surface of the wafer is flush with the upper edge of the tray. In addition, a limit block matching the wafer notch / flat is set on the inner surface of the tray. When the wafer is placed on the tray, the limit block can limit the rotation of the wafer relative to the tray. In addition, four through holes 403 matching the second lifting column 402 are set in the center of the tray.

[0126] Continue to combine Figure 8 As shown, it should be noted that the through holes 403 of the tray provided in the embodiment of the present application, if connected in sequence as vertices, can form a rectangle, and the size of the rectangle is the same as the rectangle formed by connecting four second lifting columns 402 in sequence as vertices.

[0127] Fig. 9 A schematic diagram of a through-hole alignment method provided in an embodiment of the present application. Fig. 9 As shown in (a), the tray is placed on the raised second lifting column 402 by the robot arm 201, and in the process of the second lifting column 402 placing the tray on the second rotating platform 306, since the tray in the tray box is adjusted over the flat edge, the long side of the rectangle formed by the through holes 403 connected in sequence is perpendicular to the long side of the rectangle formed by the second lifting column 402 as the vertex (the figure formed by the through holes connected in sequence and the polygon formed by the second lifting column as the vertex are at a specific angle). The pre-alignment program can be set to that after the center alignment is completed, the second rotating platform 306 rotates the flat edge of the tray to an angle that is perpendicular to the long side of the rectangle formed by the second lifting column 402 as the vertex. In this way, when the pre-alignment of the tray is completed, the second rotating platform 306 rotates the tray counterclockwise by 90° (specific angle), and rotates the through hole 403 of the tray to correspond to the second lifting column 402, so that the second lifting column 304 can pass through the through hole 403 when it is raised, and does not lift the tray, so that it can receive the wafer and put it down for assembly.

[0128] It should be noted that in the embodiment of the present application, after the tray is rotated counterclockwise by 90°, the long sides of the rectangle formed by the flat side of the tray and the second lifting column 402 as vertices are connected in sequence are parallel to each other. In order to accurately place the wafer in the tray, the flat side angle of the pre-aligned wafer should be consistent with the flat side angle of the tray at this time (flat side facing up). Of course, the flat sides of the wafer and the tray are both facing downward, which can also enable the second lifting column 402 to pass through the through hole 403 when it is raised, and accurately combine the wafer and the tray. The specific setting method can be flexibly adjusted by the staff.

[0129] As an implementation manner, regarding how to perform alignment, when placing the wafer, the robot arm 201 is used to move the tray carrying the wafer from the process module 102 to the second pre-alignment device 203;

[0130] The second pre-alignment device 203 is used to pre-align the tray carrying the wafer;

[0131] The robot arm 201 is further used to move the wafer on the pre-aligned tray to the wafer box, and move the tray to the tray box.

[0132] During the wafer retrieval process, the tray carrying the wafer is transported from the second pre-alignment device 203 to the process module 102 by the robot arm 201 and the process is carried out. When the process is completed, the process module 102 unloads the wafer, and the alignment system continues the wafer placement process. Specifically, during the wafer placement process, the robot arm 201 first transports the tray carrying the wafer from the process module 102 to the second pre-alignment device 203. Then, the second pre-alignment device 203 pre-aligns the tray carrying the wafer. When the center alignment is completed, the second rotating platform 306 rotates the through hole 403 of the tray to correspond to the second lifting column 402, so that the second lifting column 402 can pass through the through hole 403 when it is raised, and the tray is not lifted, and then the wafer is lifted alone, and the wafer is transported to the wafer box by the robot arm 201. Finally, the second rotating platform 306 rotates the flat edge of the pallet to an angle perpendicular to the long sides of the rectangle formed by connecting the second lifting columns 402 as vertices in sequence, and the second lifting columns 402 lift the pallet and connect it to the robotic arm 201. The robotic arm 201 moves the pallet to the pallet box, completing the entire film placement process.

[0133] In summary, the present application provides an alignment system and method, the system comprising: a device front-end module and a process module; the device front-end module comprises a robotic arm, a first pre-alignment device and a second pre-alignment device; when taking a wafer, the robotic arm is used to transport the wafer from the wafer box to the first pre-alignment device, and transport the tray from the tray box to the second pre-alignment device; the first pre-alignment device is used to pre-align the wafer; the second pre-alignment device is used to pre-align the tray; the robotic arm is also used to transport the pre-aligned wafer to the top of the pre-aligned tray, and the second pre-alignment device places the wafer into the tray; the robotic arm is also used to transport the tray carrying the wafer to the process module; the process module is used to receive the tray and process the wafer carried by the tray. Thus, the wafer and the tray are pre-aligned respectively by two pre-alignment devices, which reduces the number of transports and improves the pre-alignment accuracy.

[0134] Fig.10 A flowchart of an alignment method in a film picking process provided by an embodiment of the present application. Fig.10 As shown, an embodiment of the present application provides an alignment method in a film taking process, comprising:

[0135] S1001: Using a robotic arm to obtain a wafer from a wafer box and transport it to a first pre-alignment device for pre-alignment.

[0136] In the actual wafer removal process, the wafer loading port first opens the wafer box, and then the robotic arm takes the wafer from the wafer box and transports it to the first pre-alignment device for pre-alignment. Specifically, Fig.11 A schematic diagram of a wafer pre-alignment process provided in an embodiment of the present application. Fig.11As shown, the first lifting column first rises to the handover height and receives the wafer from the robot arm. Then the first lifting column is lowered and docked with the first rotating platform, and the wafer is placed on the first rotating platform for fixing. As can be seen from (a), the center of the wafer is not aligned at this time, and there is an eccentricity e between the center of the wafer and the center of the first rotating platform. Then, the wafer is driven by the first rotating platform to rotate, and its edge will partially block the first linear light. Based on photoelectric conversion, the wafer can form a sine-like voltage waveform during the rotation process. The center point of the wafer is calculated through the waveform and the direction of the notch / flat of the wafer is determined. After determination, the first rotating platform drives the wafer to rotate and rotates the eccentricity e (the line connecting the center of the wafer and the center of the first rotating platform) to a direction parallel to the X-axis. Then, as shown in (b), the first lifting column rises and lifts the wafer. Then, as shown in (c), the first lifting column moves the distance of the eccentricity e along the X-axis direction toward the center of the first rotating platform to achieve center alignment of the wafer. Finally, the first lifting column is lowered, and the wafer is placed on the first rotating platform. The first rotating platform rotates the flat edge of the wafer to a preset angle and stops, and then the first lifting column is raised to lift the wafer to complete the wafer pre-alignment process. As shown in (d), the first lifting column is raised to the wafer handover height, waiting for the robotic arm to take the wafer away.

[0137] S1002: Using a robotic arm to obtain a tray from a tray box, and transporting the tray to a second pre-alignment device for pre-alignment; the flat edge of the wafer after pre-alignment has the same angle as the flat edge of the tray after pre-alignment.

[0138] In the actual wafer removal process, the pre-alignment process of the tray is the same as the pre-alignment process of the wafer. First, the tray box is opened by the tray loading port, and then the robot arm takes the tray from the tray box and moves it to the second pre-alignment device for pre-alignment. Specifically, Fig.12 A schematic diagram of a tray pre-alignment process provided in an embodiment of the present application. Fig.12As shown, the second lifting column receives the tray and places it on the second rotating platform. At this time, the center of the tray is not aligned with the center of the second rotating platform, as shown in (a). Then, the second rotating platform drives the tray to rotate. Based on photoelectric conversion, the tray can form a sine-like voltage waveform during the rotation process. The center point of the tray is calculated through the waveform and the direction of the notch / flat of the tray is determined. After determination, the eccentricity e is rotated to a direction parallel to the X-axis. Then, as shown in (b), the second lifting column rises and lifts the tray. Then, as shown in (c), the second lifting column moves the distance of the eccentricity e along the X-axis direction toward the center of the second rotating platform to achieve the center alignment of the tray. Finally, the second rotating platform drives the tray to rotate so that the four through holes on the tray correspond to the four second lifting columns, so that the second lifting column can pass through the through holes when it is lifted, and the tray is not lifted, completing the pre-alignment process of the tray. It should be noted that the flat edge of the pre-aligned wafer and the flat edge of the pre-aligned tray are consistent in angle, thereby ensuring that the wafer and the tray can be aligned and combined.

[0139] S1003: Use a robotic arm to move the pre-aligned wafer to above the tray, and use the second pre-alignment device to place the wafer into the tray.

[0140] Fig.13 A flowchart of a combination method provided in an embodiment of the present application. Fig.13 As shown, the second lifting column corresponds to the through hole of the tray, so that the second lifting column can pass through the through hole when it is raised without lifting the tray, thereby completing the pre-alignment process of the tray. As shown in (a), in the assembly stage, the second lifting column rises and passes through the through hole of the tray to reach the wafer handover height. As shown in (b), the robotic arm moves the pre-aligned wafer to the top of the tray and places it on the second lifting column. It should be noted that at this time, the flat edge angle of the tray is consistent with the flat edge angle of the wafer. As shown in (c), the second lifting column is lowered, and the wafer falls into the tray, completing the wafer loading action, and the wafer and tray are combined.

[0141] S1004: Use a robot arm to move the tray loaded with the wafers to a process module and perform a process.

[0142] Fig.14 A schematic diagram of a process for transporting a tray carrying wafers to a process module is provided in an embodiment of the present application. Fig.14As shown, the second rotating platform drives the tray carrying the wafers to rotate so that the through holes of the tray do not correspond to the second lifting columns (generally, the tray is rotated 90° counterclockwise so that the long sides of the rectangle formed by the through holes connected in sequence and the long sides of the rectangle formed by the second lifting columns as vertices are perpendicular to each other). At this time, the second lifting column rises, lifts the tray carrying the wafers to the handover height, and the robot arm moves the tray carrying the wafers to the process module for processing.

[0143] In summary, an alignment method in a wafer picking process provided by an embodiment of the present application first uses a robotic arm to obtain a wafer from a wafer box and transport it to a first pre-alignment device for pre-alignment. Then, a tray is obtained from a tray box by a robotic arm and transported to a second pre-alignment device for pre-alignment. Among them, the flat edge of the pre-aligned wafer and the flat edge of the pre-aligned tray have the same angle. Then, the pre-aligned wafer is transported to the top of the tray by a robotic arm, and the wafer is placed in the tray by a second pre-alignment device. Finally, the tray loaded with the wafer is transported to the process module by a robotic arm, and the process is performed. In this way, the wafer and the tray are pre-aligned respectively by two pre-alignment devices, which reduces the number of transports and improves the pre-alignment accuracy.

[0144] Fig.15 A flowchart of an alignment method in a film placement process provided by an embodiment of the present application. Fig.15 As shown, the embodiment of the present application provides an alignment method during the film placement process, including:

[0145] S1501: using a robot arm to obtain a tray carrying wafers after the process is completed from a process module, and transporting it to a second pre-alignment device;

[0146] S1502: Pre-aligning the tray carrying the wafer using a second pre-alignment device;

[0147] S1503: Use a robotic arm to move the wafer on the pre-aligned tray to a wafer box, and move the tray to a tray box.

[0148] In actual applications, wafer placement is required after the process is completed. The robotic arm takes out the tray carrying the wafer from the process module and places it on the second lifting column in the second pre-alignment device and lifts it to the handover height. Then the second lifting column is lowered and the tray is placed on the second rotating platform, which drives the tray to rotate and pre-align in the same way as when taking the wafer. After the center alignment is completed, the second rotating platform drives the tray to continue rotating so that the through hole of the tray corresponds to the second lifting column. In this way, when the second lifting column is raised, it can lift the wafer alone through the through hole and hand it over to the robotic arm, so that the robotic arm can move the wafer back to the wafer box. Then the second lifting column is lowered, and the second rotating platform continues to drive the tray to rotate until the through hole of the tray does not correspond to the second lifting column. At this time, the second lifting column is raised again to lift the tray to the handover height, and the robotic arm moves the tray back to the tray box and completes the wafer placement action.

[0149] In summary, the embodiment of the present application provides an alignment method during the wafer placement process, firstly, a tray carrying wafers after the process is completed is obtained from the process module by a robotic arm, and is transported to a second pre-alignment device. Then, the tray carrying the wafers is pre-aligned by the second pre-alignment device. Finally, the wafers on the pre-aligned tray are transported to a wafer box by a robotic arm, and the tray is transported to a tray box. In this way, the wafer placement is performed by relying on a single pre-alignment device, thereby improving the efficiency of wafer placement.

[0150] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An alignment system, characterized in that: include: Equipment front-end module and process module; The equipment front-end module includes a mechanical arm, a first pre-alignment device and a second pre-alignment device; When taking out a wafer, the robot arm is used to move the wafer from the wafer box to the first pre-alignment device, and move the tray from the tray box to the second pre-alignment device; The first pre-alignment device is used to pre-align the wafer; The second pre-alignment device is used to pre-align the tray; The robot arm is also used to carry the pre-aligned wafer to the top of the pre-aligned tray, and the second pre-alignment device places the wafer into the tray; The robot arm is also used to transport the tray carrying the wafer to the process module; the process module is used to receive the tray and perform processing on the wafer carried by the tray.

2. The system according to claim 1, characterized in that The first pre-alignment device comprises: a first linear sensor, a first lifting assembly and a first rotating platform; The first lifting assembly is used to dock with the robotic arm when it is lifted, and receive the wafer carried by the robotic arm; The first lifting assembly is used to dock with the first rotating platform when it is lowered, so as to place the wafer on the first rotating platform; The first rotating platform is used to fix the wafer and drive the wafer to rotate; The first linear sensor includes a first receiving end and a first transmitting end, the first transmitting end is used to generate a first linear light emitted to the first receiving end; the first receiving end is used to receive the first linear light blocked by the rotating wafer, and determine the center of the wafer based on photoelectric conversion; The first lifting assembly is also used to move the wafer after centering, and to align the center of the wafer with the first rotating platform; The first rotating platform is also used to perform flat edge alignment on the center-aligned wafer.

3. The system according to claim 2, characterized in that The first linear light has a specific length, is partially blocked by the wafer fixed on the first rotating platform, and is perpendicular to both the wafer and the first receiving end.

4. The system according to claim 2, characterized in that The first lifting assembly includes at least three first lifting columns, and the first lifting columns are connected in sequence as vertices to form a polygon.

5. The system according to claim 4, characterized in that All of the first lifting columns are connected to the same movement control assembly; The movement control assembly is used to control each of the first lifting columns to move in the same direction.

6. The system according to claim 1, characterized in that The second pre-alignment device comprises: a second linear sensor, a second lifting assembly and a second rotating platform; During the pre-alignment process of the pallet, the second lifting assembly is used to dock with the robotic arm when it is raised, and receive the pallet carried by the robotic arm; The second lifting assembly is used to dock with the second rotating platform when it is lowered, so as to place the tray on the second rotating platform; The second rotating platform is used to fix the tray and drive the tray to rotate; The second linear sensor includes a second receiving end and a second transmitting end, the second transmitting end is used to generate a second linear light emitted to the second receiving end; the second receiving end is used to receive the second linear light blocked by the rotating tray, and determine the center of the tray based on photoelectric conversion; The second lifting assembly is also used to move the tray after the center is determined, and to align the center of the tray with the second rotating platform; The second rotating platform is also used to align the center-aligned tray with flat edges.

7. The system according to claim 6, characterized in that The second linear light has a specific length, is partially blocked by the tray fixed on the second rotating platform, and is perpendicular to both the tray and the second receiving end.

8. The system according to claim 6, characterized in that The second lifting assembly includes at least three second lifting columns, and each of the second lifting columns is connected in sequence as a vertex to form a polygon.

9. The system according to claim 8, characterized in that All of the second lifting columns are connected to the same movement control assembly; The movement control assembly is used to control each of the second lifting columns to move in the same direction.

10. The system according to claim 6, characterized in that The upper surface of the tray is provided with a groove for placing the wafer, and the depth of the groove is the same as the thickness of the wafer; The inner surface of the tray is provided with a limiting block corresponding to the flat edge of the wafer, so as to limit the rotation of the wafer relative to the tray.

11. The system according to claim 8, characterized in that The tray is provided with through holes whose number matches the number of the second lifting columns, and the figure formed by sequentially connecting the through holes is consistent with the polygon formed by sequentially connecting the second lifting columns as vertices; When the tray is placed on the second rotating platform by the second lifting column, a figure formed by sequentially connecting the through holes and a polygon formed by sequentially connecting the through holes with the second lifting column as a vertex form a specific angle; When the pre-alignment of the pallet is completed, the second rotating platform rotates the pallet counterclockwise by a specific angle to align the through hole of the pallet with the second lifting column so that the second lifting column can pass through the through hole when it is raised without lifting the pallet.

12. The system according to claim 11, characterized in that The number of the second lifting components and the number of the through holes are both four; The figure formed by the four through holes connected in sequence and the polygon formed by the four second lifting columns as vertices connected in sequence are both rectangles; when the tray is placed on the second rotating platform by the second lifting columns, the long sides of the rectangle formed by the through holes connected in sequence and the long sides of the rectangle formed by the second lifting columns as vertices connected in sequence are perpendicular to each other; When the pre-alignment of the pallet is completed, the second rotating platform rotates the pallet counterclockwise by 90° to align the through hole of the pallet with the second lifting column so that the second lifting column can pass through the through hole when it is raised without lifting the pallet.

13. The system according to claim 12, characterized in that After the tray is rotated 90° counterclockwise, the flat edge of the tray is consistent with the flat edge angle of the wafer after pre-alignment.

14. The system according to claim 1, characterized in that When placing the wafer, the robot arm is used to move the tray carrying the wafer from the process module to the second pre-alignment device; The second pre-alignment device is used to pre-align the tray carrying the wafer; The robot arm is also used to transport the wafer on the pre-aligned tray to the wafer box, and to transport the tray to the tray box.

15. An alignment method in a film taking process, characterized in that: The method is applied to the alignment system according to any one of claims 1 to 14, and the method comprises: Using a robotic arm to obtain a wafer from a wafer box and transport it to a first pre-alignment device for pre-alignment; Using a robotic arm to obtain a tray from a tray box, and transporting it to a second pre-alignment device for pre-alignment; the flat edge of the wafer after pre-alignment and the flat edge of the tray after pre-alignment have the same angle; Using a robot arm to move the pre-aligned wafer to above the tray, and using the second pre-alignment device to place the wafer into the tray; The tray loaded with the wafers is transported to a process module by a robotic arm and processed.

16. An alignment method during film placement, characterized in that: The method is applied to the alignment system according to any one of claims 1 to 14, and the method comprises: Using a robotic arm to obtain the tray carrying the wafer after the process is completed from the process module, and transport it to the second pre-alignment device; Pre-aligning the tray carrying the wafer using a second pre-alignment device; The wafer on the pre-aligned tray is transported to a wafer box by a robot arm, and the tray is transported to a tray box.

Images