Wafer Transfer Device and Method

Abstract

The present application discloses a wafer transfer device and method. The wafer transfer device includes: a manipulator, a controller, at least one set of pressure sensors, and a calibration platform; the manipulator includes a carrier plate, and a plurality of grooves are provided on the surface of the carrier plate. Each groove is axially symmetric about the center of the carrier plate, and the grooves are used to form an adsorption space when the carrier plate carries a wafer; each set of pressure sensors includes two sensor units, and the two sensor units are respectively arranged at the top of the same side wall of the same groove and are axially symmetric about the center, and are used to measure the pressure information borne by the wafer at the corresponding measurement points when the manipulator carries the wafer, and transmit the pressure information to the controller; the controller is used to control the manipulator to return the carried wafer to the calibration platform when the pressure information measured by at least one set of pressure sensors does not match, and after adjusting the relative position of the wafer on the calibration platform, control the manipulator to re-adsorb the wafer. The present application can stably transfer wafers.

Description

Technical Field

[0001] This application relates to the technical field of semiconductor process control, and particularly relates to a wafer transfer device and method. Background Art

[0002] When a wafer is taken out from a front opening unified pod (FOUP) and transferred to a corresponding vacuum pre-pumping chamber (LoadLock) by a manipulator, if abnormal working conditions such as the transfer position and transfer speed of the wafer occur, it will seriously affect the stability of automatic transfer. Therefore, a manipulator that can accurately control the transfer stability of the wafer is the guarantee for stable wafer transfer. However, in the process of using a manipulator to transfer wafers in traditional solutions, it is difficult to monitor and / or adjust the parameters that affect stable transfer, which easily affects the transfer effect of the wafers. Summary of the Invention

[0003] In view of this, this application provides a wafer transfer device and method to solve the problem that in the process of using a manipulator to transfer wafers in traditional solutions, it is difficult to monitor and / or adjust the parameters that affect stable transfer, which easily affects the transfer effect of the wafers.

[0004] A wafer transfer device provided by this application includes: a manipulator, a controller, at least one group of pressure sensors, and a calibration platform;

[0005] The manipulator includes a carrier plate, and a plurality of grooves are provided on the surface of the carrier plate. Each groove is axially symmetric about the center of the carrier plate, and the groove is used to form an adsorption space when the carrier plate carries the wafer;

[0006] The calibration platform is used to calibrate the relative position between the wafer and the carrier plate;

[0007] Each group of pressure sensors includes two sensor units. The two sensor units are respectively arranged at the top of the same side wall of the same groove and are axially symmetric about the center. When the manipulator carries the wafer, they are used to measure the pressure information borne by the wafer at the corresponding measurement points and transmit the pressure information to the controller;

[0008] The controller is used to control the manipulator to return the carried wafer to the calibration platform when the pressure information measured by at least one group of pressure sensors does not match, and after the calibration platform adjusts the relative position of the wafer, control the manipulator to re-adsorb the wafer.

[0009] Optionally, the wafer transfer device includes multiple sets of the pressure sensors; the wafer transfer device further includes a pulse width modulation module, which is connected to the controller and the manipulator, and is configured to output control pulses to the manipulator, and the pulse width of the control pulse is proportional to the transfer speed of the manipulator; the controller is further configured to, when the manipulator transfers the wafer and the pressure information measured by any one of the sensor units is greater than or equal to a preset pressure value, obtain a pressure average value according to the pressure information measured by each of the sensor units, calculate the motor speed corresponding to the manipulator according to the pressure average value, and output a pulse width control signal corresponding to the motor speed to the pulse width modulation module, so that the pulse width modulation module outputs corresponding control pulses to the manipulator according to the pulse width control signal.

[0010] Optionally, the controller is further configured to obtain a pressure range difference between a maximum value and a minimum value in the pressure information on either side of the central axis of the carrier plate, and when the pressure range difference is greater than or equal to a preset range difference threshold, control the manipulator to transfer the wafer back to the calibration platform.

[0011] Optionally, through holes penetrating the carrier plate are formed in the carrier plate; the grooves are parallel to each other and are all communicated with the through holes.

[0012] Optionally, the two ends of the carrier plate in the direction of the central axis are respectively a front end and a rear end, and the front end has an arc-shaped edge protruding towards the center of the carrier plate, the groove is arc-shaped, and the two ends of the groove are located on both sides of the central axis and extend to the arc-shaped edge.

[0013] Optionally, all the sensor units are arranged in the area between the front end of the carrier plate and the through hole.

[0014] Optionally, the wafer transfer device further includes a vacuum adsorption mechanism; the vacuum adsorption mechanism is arranged at the bottom of the carrier plate and communicated with the through hole.

[0015] Optionally, all the sensor units are distributed on the same straight line, and the straight line is perpendicular to the central axis.

[0016] The present application further provides a wafer transfer method, which is applied to any one of the above wafer transfer devices, and the wafer transfer method includes:

[0017] When the carrier plate carries the wafer, obtain the pressure information measured by at least one set of the sensor units;

[0018] When the pressure information measured by at least one group of the sensor units does not match, control the manipulator to return the carried wafer to the calibration platform, so that after the position of the wafer relative to the carrier plate is adjusted on the calibration platform, the manipulator adsorbs the wafer again for transmission.

[0019] Optionally, the wafer transfer device includes multiple groups of the pressure sensors; the wafer transfer method further includes: when the manipulator transfers the wafer and the pressure information measured by any one of the sensor units is greater than or equal to a preset pressure value, obtaining a pressure average value according to the pressure information measured by each of the sensor units, calculating the motor rotation speed corresponding to the manipulator according to the pressure average value, and outputting a pulse width control signal corresponding to the motor rotation speed to the pulse width modulation module, so that the pulse width modulation module outputs corresponding control pulses to the manipulator according to the pulse width control signal.

[0020] Optionally, the wafer transfer method further includes: obtaining a pressure range between a maximum value and a minimum value in the pressure information on any one side of the central axis of the carrier plate, and when the pressure range is greater than or equal to a preset range threshold, controlling the manipulator to return the wafer to the calibration platform.

[0021] Optionally, the calculation formula of the motor rotation speed includes: Fx = k * n + 1, where Fx represents the pressure average value, n represents the motor rotation speed, k represents an adjustment coefficient, and the symbol * represents multiplication.

[0022] In the above wafer transfer device and method, a plurality of grooves are provided on the surface of the carrier plate of the manipulator. These grooves can form an adsorption space when the carrier plate carries the wafer, increasing the suction force between the carrier plate and the wafer and improving the stability during the wafer carrying process; a group of pressure sensors are arranged at the top of the same side wall of the same groove. When the manipulator adsorbs the wafer, each group of pressure sensors measures the pressure information borne by the wafer at the corresponding measurement points and transmits the pressure information to the controller. In this way, when the pressure information measured by at least one group of pressure sensors does not match, the controller can control the manipulator to return the wafer to the calibration platform, so that after the position of the wafer relative to the carrier plate is adjusted on the calibration platform, the manipulator adsorbs the wafer again, which can timely adjust the relative position between the wafer and the carrier plate when it is found that the wafer has a position offset, and can avoid situations such as the wafer slipping and / or being damaged during subsequent transmission, ensuring the uniformity and stability of the pressure information received by the wafer.

[0023] When the above wafer transfer device and method transfer a wafer with a manipulator and the pressure information measured by any sensor unit is greater than or equal to a preset pressure value, the average pressure is obtained, the motor speed corresponding to the manipulator is calculated, and a pulse width control signal corresponding to the motor speed is output to a pulse width modulation module, so that the pulse width modulation module outputs corresponding control pulses to the manipulator according to the pulse width control signal, and the transfer speed of the manipulator is adjusted to a speed matching the average pressure, so as to reduce the risk of problems such as uneven stress, deformation, and / or position offset caused by excessive pressure on the wafer, and further improve the reliability of the wafer transfer process. It is also possible to obtain the pressure difference between the maximum value and the minimum value of the pressure information on either side of the central axis of the carrier, and when the pressure difference is greater than or equal to a preset difference threshold, control the manipulator to return the wafer to the calibration platform, so that the calibration platform can timely adjust the position of the wafer relative to the carrier and reduce the probability of the wafer sliding.

[0024] It can be seen that the above wafer transfer device and method can timely adjust the position of the wafer relative to the carrier, reasonably control the transfer speed, and improve the stability of the wafer transfer process in multiple aspects. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present application. For those skilled in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0026] Figure 1 is a schematic diagram of the manipulator trajectory planning of the existing solution;

[0027] Figure 2 is a schematic structural diagram of a wafer transfer device according to an embodiment of the present application;

[0028] Figure 3a 、 Figure 3b 、 Figure 3c and Figure 3d is a schematic diagram of the finger structure according to an embodiment of the present application;

[0029] Figure 4 is a schematic diagram of the force analysis of the wafer according to an embodiment of the present application;

[0030] Figure 5 is a schematic structural diagram of a wafer transfer device according to another embodiment of the present application;

[0031] Figure 6 is a schematic diagram of the working process of the wafer transfer device according to an embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0032] In the process of using a manipulator to transfer wafers in the traditional solution described in the background art, it is difficult to monitor and / or adjust the parameters that affect stable transfer, which easily affects the wafer transfer effect. In the traditional solution, the wafer transfer process often has a manipulator movement path as shown in Figure 1 The manipulator takes the wafer out of the cassette, transfers it to the calibration platform, and then transfers it to the subsequent processing equipment after calibration. There are very clear requirements for the shape and accuracy of the corresponding motion trajectory throughout the process. The motion path of the end of the transfer robot in space can be obtained through the teaching method, or the positions of the end of the robot can be calculated in the path planner first to obtain the motion path. As shown in Figure 1 The manipulator first picks up the wafer from the cassette (FOUP), transfers it to the correction platform, and then transfers it to the vacuum pre-pumping chamber (LoadLock) after correction by the correction platform. The inventor found that this manipulator trajectory planning emphasizes the coordinate values of each path point and can only transfer at a pre-set speed to ensure the accuracy of the path.

[0033] During the wafer transfer process, the wafer is extremely likely to slip or collide with the equipment, resulting in damage to the manipulator fingers and the wafer. In addition, during the wafer transfer process, the uncontrollable transfer speed will cause vibration of the manipulator fingers, which may cause the wafer to fall, generate contaminated dust, or cause the wafer to fall off, affecting its cleanliness and flatness, resulting in economic losses.

[0034] Based on the above analysis, the inventor proposes to introduce control over working conditions such as the transfer position and transfer speed of the wafer during the wafer transfer process to ensure the stable and reliable wafer transfer process, thereby improving the smoothness of the production of the corresponding semiconductor equipment.

[0035] Based on this idea, the present application provides a new wafer transfer device and method, which can detect the pressure information of the manipulator when carrying the wafer in real time during the wafer transfer process, and adjust the position of the wafer relative to the carrier plate and the wafer transfer speed in a timely manner according to the pressure information, so as to improve the stability of the wafer transfer process, thereby reducing the risk of wafer dropping and / or falling off, and ensuring the cleanliness and flatness of the wafer during the corresponding transfer process.

[0036] Next, in conjunction with the accompanying drawings, the technical solutions in the embodiments of the present application will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present application. Without conflict, the following various embodiments and their technical features can be combined with each other.

[0037] The first aspect of the present application provides a wafer transfer device. Refer to Figure 2As shown, the above-mentioned wafer transfer device includes: a robot 100, a controller 200, at least one group of pressure sensors 110, and a calibration platform (not shown in the figure).

[0038] The robot 100 includes a carrier plate. The surface of the carrier plate is provided with a plurality of grooves, and each groove is axially symmetric about the center of the carrier plate. The grooves are used to form an adsorption space when the carrier plate carries the wafer, so as to increase the suction force between the carrier plate and the wafer and improve the stability during the wafer carrying process;

[0039] The calibration platform is used to calibrate the relative position between the wafer and the carrier plate.

[0040] Each group of pressure sensors 110 includes two sensor units. The two sensor units are respectively arranged at the top of the same side wall of the same groove and are axially symmetric about the center. When the robot 100 carries a wafer, they are used to measure the pressure information borne by the wafer at the corresponding measurement points and transmit the pressure information to the controller 200; among them, each sensor unit has a corresponding measurement point, and the measurement point is located at the contact position between the corresponding sensor unit and the wafer.

[0041] When the pressure information measured by at least one group of pressure sensors 110 does not match, the controller 200 is used to control the robot 100 to send the carried wafer back to the calibration platform, and after the calibration platform adjusts the relative position of the wafer, control the robot to re-adsorb the wafer, so that the carrier plate of the robot can carry the wafer more stably and improve the reliability of the subsequent transfer process.

[0042] Specifically, the side wall of each groove can form a rib relative to the groove. Each side wall is axially symmetric about the center of the carrier plate. The top of the side wall is aligned with the surface of the carrier plate and contacts the wafer when the carrier plate carries the wafer, so that the acting force between the contact surfaces of the wafer and the carrier plate is more uniform. The sensor unit is arranged at the top of the side wall, so that when the carrier plate of the robot 100 carries the wafer, the sensor unit contacts the surface of the carrier plate and the wafer at the same time, so that the sensor unit can more accurately measure the acting force exerted by the carrier plate on the wafer. Optionally, the size of the sensor unit is small enough, so that after the sensor unit is arranged at the top of the side wall, when the carrier plate adsorbs the wafer, the sensor unit will not interfere with the adsorption process.

[0043] For the above wafer transfer device, a plurality of grooves are provided on the surface of the carrier plate of the manipulator 100. When the carrier plate holds the wafer, these grooves can form an adsorption space, increasing the suction force between the carrier plate and the wafer and enhancing the stability during the wafer holding process. At the top of the same side wall of the same groove, a set of pressure sensors 110 is provided. When the manipulator 100 adsorbs the wafer, each set of pressure sensors 110 measures the pressure information borne by the wafer at the corresponding measurement points and transmits the pressure information to the controller 200. In this way, when the pressure information measured by at least one set of pressure sensors does not match, the controller 200 can control the manipulator 100 to send the wafer back to the calibration platform. After adjusting the position of the wafer relative to the carrier plate on the calibration platform, the manipulator adsorbs the wafer again, enabling timely adjustment of the relative position between the wafer and the carrier plate when it is found that the wafer has a position offset, and can avoid situations such as the wafer slipping and / or being damaged during subsequent transfer, ensuring the uniformity and stability of the pressure information received by the wafer.

[0044] In one embodiment, the carrier plate has through holes penetrating the carrier plate; the grooves are arranged parallel to each other and are all communicated with the through holes; in this way, when the carrier plate holds the wafer, the vacuum adsorption mechanism and other adsorption devices can suck the gas in each groove through the through holes, causing the grooves to form an adsorption space.

[0045] In one example, the two ends of the carrier plate in the central axis direction are the front end and the rear end respectively, and the front end has an arc-shaped edge protruding towards the center of the carrier plate. The groove is arc-shaped to facilitate the flow of air and other gases, ensuring the stability of the air flow in the groove when the vacuum adsorption mechanism and other adsorption devices extract gas, and thus ensuring the stability of the air flow and the corresponding pressure when adsorbing the corresponding wafer; the two ends of the groove are located on both sides of the central axis and extend to the arc-shaped edge, so that the space of the groove is large enough to provide a large enough adsorption space, thereby enhancing the adsorption force corresponding to the corresponding adsorption space.

[0046] Specifically, all sensor units are arranged in the area between the front end of the carrier plate and the through hole, so that all sensor units are located at the front end of the carrier plate. Since the wafer part at the front end of the carrier plate is more likely to shake, the sensor units placed at these positions are more sensitive to the change in the force on the wafer. Therefore, by arranging all sensor units at the front end of the carrier plate, the change characteristics of the pressure information measured by each sensor unit can be obtained more accurately during the measurement process.

[0047] In one example, the wafer transfer device further includes a vacuum adsorption mechanism for extracting gas; the vacuum adsorption mechanism is disposed at the bottom of the carrier plate and communicated with the through hole; it is used to establish the vacuum degree between the carrier plate and the wafer to adsorb the wafer on the surface of the carrier plate and ensure the stability when adsorbing the wafer. The vacuum adsorption mechanism may include a vacuum tube, and the vacuum tube may be connected to the through hole to extract the gas between the surface of the carrier plate and the wafer through the through hole, so as to form a negative pressure between the carrier plate and the wafer.

[0048] In one embodiment, the wafer transfer device includes multiple groups of pressure sensors 110 to respectively measure the pressure information received by the wafer at the corresponding measurement points at the top of the corresponding side wall, ensuring the integrity and effectiveness of the measured pressure information. All the sensor units are distributed on the same straight line, and the straight line is perpendicular to the central axis; in this way, the change trends of the pressure information measured by the sensor units on both sides of the central axis are the same, which is more convenient for the controller 200 to compare and analyze all the pressure information, and can simplify the corresponding comparison and analysis process.

[0049] Optionally, the carrier plate of the manipulator 100 can also be referred to as a finger, and the finger structure can refer to Figures 3a to 3d as shown, where Figure 3a and Figure 3c are top views, Figure 3b and Figure 3d are side views. As Figure 3a and 3b shown, the finger 16 is divided into two sides by the central axis, and the respective structural parts on both sides are symmetric about the central axis. The finger 16 adopts an arc design for placing the wafer. The finger 16 internally includes multiple grooves. If the central axis is taken as the inner side, both sides of the central axis are the outer sides. Figures 3a to 3d The first groove 11, the second groove 12, the third groove 13, and the fourth groove 14 are successively shown from the outside to the inside. Each groove includes two parts symmetric about the central axis. For example, the first groove 11 includes 11A and 11B, the second groove 12 includes 12A and 12B, the third groove 13 includes 13A and 13B, and the fourth groove 14 includes 14A and 14B; each groove shown in the figure has a hollow annular structure to facilitate the gas flow inside the groove and ensure the uniformity and stability of the air flow generated when the gas is extracted.

[0050] In this embodiment, two sensor units in each group of pressure sensors 110 are disposed at the top of the same side wall and are symmetric about the central axis; for example, refer to Figure 3b and Figure 3cAs shown, the pressure sensor 110 includes a first group of pressure sensors, a second group of pressure sensors, a third group of pressure sensors, a fourth group of pressure sensors, and a fifth group of pressure sensors. On the top of the side wall outside the first groove 11, there is a sensor unit 18A and another sensor unit 18J in the first group of pressure sensors (for example, on the top of the side wall outside 11A, there is a sensor unit 18A, and on the top of the side wall outside 11B, there is another sensor unit 18J); on the top of the side wall outside the second groove 12, there is a sensor unit 18B and another sensor unit 18I in the second group of pressure sensors; on the top of the side wall outside the third groove 13, there is a sensor unit 18C and another sensor unit 18H in the third group of pressure sensors; on the top of the side wall outside the fourth groove 14, there is a sensor unit 18D and another sensor unit 18G in the fourth group of pressure sensors; on the top of the side wall inside the fourth groove 14, there is a sensor unit 18E and another sensor unit 18F in the fifth group of pressure sensors.

[0051] Furthermore, the two ends of the finger 16 in the central axis direction are the front end and the rear end respectively. The front end has an arc-shaped edge protruding towards the center of the finger 16, and the rear end can be connected to structures such as a robotic arm that controls the movement of the finger 16. A through hole 15 is provided in the area of the finger 16 near the rear end, and a vacuum adsorption mechanism is installed on the back of the finger 16. The vacuum adsorption mechanism extracts the gas between the surface of the finger 16 and the wafer 19 through the above through hole 15, so that the surface of the finger 16 can adsorb the wafer 19.

[0052] Reference Figure 3c and Figure 3d As shown, after the surface of the finger 16 adsorbs the wafer 19, the top surfaces of each side wall contact the wafer 19, and each sensor unit is located between the top of the side wall and the wafer 19, and can sensitively measure the pressure information received by the wafer at the corresponding measurement points. Specifically, the above vacuum adsorption mechanism extracts the gas between the surface of the finger 16 and the wafer 19 through the through hole 15 to establish the vacuum degree between the finger 16 and the wafer 19. Optionally, the through hole 15 communicates with each groove. After the wafer 19 fits on the surface of the finger 16, the vacuum adsorption mechanism can continuously extract the gas in each groove, so that each groove forms a corresponding adsorption space respectively, and adsorbs the wafer 19 on the surface of the finger 16.

[0053] Further, the controller 200 is respectively connected to each sensor unit and the control components of the manipulator 100 (such as the robotic arm or the pulse width modulation module that controls the movement of the manipulator 100, etc.) to receive the pressure information measured by each sensor unit, and output control information to the adjustment component according to the pressure information to control the transfer process of the manipulator 100. Specifically, the controller 200 can compare and analyze the pressure information measured by each sensor unit in each group of pressure sensors 110 to monitor the real-time state of the wafer and the manipulator 100, and output control information based on its real-time state, so that the manipulator 100 can stably transfer the wafer; for example, the controller 200 can compare the pressure information measured by two sensor units in at least one group of pressure sensors 110. When the pressure information measured by the two sensor units in the same group of pressure sensors does not match, the controller 200 controls the manipulator 100 to return the wafer carried thereon to the calibration platform, etc. The controller 200 may include a control chip such as a single-chip microcomputer with high speed and low cost, and a μCOS-III real-time system can be loaded thereon to ensure the real-time performance of the corresponding control process.

[0054] Specifically, the matching of the pressure information measured by two sensor units in a group of pressure sensors 110 includes: the horizontal component forces of the two pressure information are equal in magnitude and opposite in direction, and the vertical component forces are equal in magnitude and the same in direction; if in a group of pressure information, the two pressures do not meet the condition that the horizontal component forces are equal in magnitude and opposite in direction, and the vertical component forces are equal in magnitude and the same in direction, it can be determined that the group of pressure information does not match. Among them, the horizontal direction may include the direction perpendicular to the central axis of the carrier plate on the surface of the carrier plate, and the vertical direction may include the direction perpendicular to the surface of the carrier plate. Taking Figure 3c the pressure information measured by the two sensor units 18A and 18J in the first group of pressure sensors shown as an example to analyze the force state of the wafer, refer to Figure 4As shown, if the pressure values (pressure information of the wafer) measured by these two sensor units are P1 and N1 respectively, P1 is decomposed into a horizontal force P2 and a vertical force P3, and N1 is decomposed into a horizontal force N2 and a vertical force N3. If the wafer is in the correct position, according to the principle of force balance, it can be known that the horizontal component forces P2 and N2 are equal in magnitude and opposite in direction, and the vertical component forces P3 and N3 are equal in magnitude and in the same direction. This force-bearing state of the two sensor units in the same group of pressure sensors is a matching state. For the pressure values measured by the two sensor units in each group of pressure sensors or the overall forces respectively corresponding to both sides of the wafer to be in a matching state, the position of the wafer is non-offset. If the pressure values measured by the two sensor units of any group of pressure sensors do not match, there may be a position offset, resulting in situations such as the wafer slipping. Therefore, when the pressure information measured by the two sensor units of at least one group of pressure sensors does not match, the controller 200 controls the manipulator 100 to send the carried wafer back to the calibration platform. After the calibration platform receives the wafer, it adjusts the relative position between the wafer and the carrier plate. After the controller 200 adjusts the relative position of the wafer on the calibration platform, it controls the manipulator 100 to re-adsorb the wafer. In this way, when the relative position between the wafer and the carrier plate is correct, the wafer can be re-adsorbed by the carrier plate and transmitted by the manipulator 100. Specifically, after the carrier plate re-adsorbs the wafer, each sensor unit can continue to measure the pressure information that the wafer bears at the corresponding measurement points and send the corresponding pressure information to the controller 200. The controller 200 can also return to execute the process of controlling the manipulator 100 to send the carried wafer back to the calibration platform when the pressure information measured by at least one group of pressure sensors 110 does not match, until the controller detects that the pressure information measured by each group of pressure sensors 110 matches, and the carrier plate can stably adsorb the wafer, which can avoid situations such as the wafer slipping and / or being damaged during subsequent transmission, and ensure the uniformity and stability of the pressure information received by the wafer.

[0055] In one embodiment, after the carrier plate of the manipulator 100 adsorbs the wafer, if the pressure information measured by each group of pressure sensors 110 matches, the controller 200 determines that the relative position between the wafer and the carrier plate is non-offset, starts the motor corresponding to the manipulator 100 at the initial transmission speed, and controls the manipulator 100 to start transmitting the adsorbed wafer at the initial transmission speed. During the process of transmitting the wafer, the controller 200 continues to obtain the pressure information measured by the two sensor units in each group of pressure sensors 110 respectively to control the wafer transmission process according to each pressure information. The initial transmission speed can be determined according to factors such as the type of wafer to be transmitted. For example, it can be the speed used for transmitting the same type of wafer last time, or the average transmission speed within a set time period, or the speed set by relevant staff, etc.

[0056] In one example, the wafer transfer device further includes a pulse width modulation module; the pulse width modulation module is connected to the controller 200 and the manipulator 100, and is configured to output control pulses to the manipulator 100, and the pulse width of the control pulses is proportional to the transfer speed of the manipulator. Among them, the pulse width modulation module may include a PWM pulse width modulation module, which can output control pulses with corresponding pulse widths under the control of the controller 200 to control the transfer speed of the manipulator 100. Optionally, the control pulses may include square wave signals, the pulse width of which is proportional to the transfer speed of the manipulator 100. When the pulse width modulation module increases the pulse width of the output control pulses, the transfer speed of the manipulator 100 can be decreased; when the pulse width modulation module increases the pulse width of the output control pulses, the transfer speed of the manipulator 100 can be increased. Optionally, each rotation speed of the motor has a corresponding pulse width parameter. After the controller 200 calculates the motor rotation speed matching the average pressure, it can determine the pulse width control signal according to the pulse width parameter corresponding to the motor rotation speed, so that the pulse width modulation module can output the control pulses corresponding to the above motor rotation speed according to the pulse width control signal.

[0057] The above-mentioned controller 200 is further configured to, when the manipulator 100 transfers the wafer and the pressure information measured by any one of the sensor units is greater than or equal to the preset pressure value, obtain the average pressure according to the pressure information measured by each sensor unit, calculate the motor rotation speed corresponding to the manipulator 100 according to the average pressure, and output the pulse width control signal corresponding to the motor rotation speed to the pulse width modulation module, so that the pulse width modulation module outputs the corresponding control pulses to the manipulator according to the pulse width control signal, and adjusts the transfer speed of the manipulator 100 to the speed matching the average pressure.

[0058] The above-mentioned preset pressure value can be set according to factors such as the wafer type. If the pressure information measured by any one of the sensor units is greater than or equal to the preset pressure value, it indicates that during the process of the manipulator transferring the wafer at the corresponding speed, the pressure on the wafer is too large, and problems such as uneven stress, deformation, and / or position offset are likely to occur. It is necessary to adjust the speed in time so that the transfer speed matches the force-bearing characteristics of the wafer. At this time, the controller 200 calculates the motor rotation speed corresponding to the manipulator 100 according to the average pressure, and outputs the pulse width control signal corresponding to the motor rotation speed to the pulse width modulation module, so that the pulse width modulation module outputs the corresponding control pulses to the manipulator 100 according to the pulse width control signal. At this time, the manipulator 100 can transfer the wafer at the transfer speed corresponding to the control pulses, so that the transfer speed matches the force-bearing characteristics of the wafer, and the risk of problems such as uneven stress, deformation, and / or position offset caused by excessive pressure on the wafer can be reduced, and the reliability of the wafer transfer process can be improved. If the pressure information measured by each sensor unit is less than the preset pressure value, it indicates that the force-bearing characteristics of the wafer match the transfer speed currently adopted by the manipulator 100. Relatively speaking, during the current transfer process, the manipulator 100 can continue to transfer the wafer at the corresponding transfer speed.

[0059] Optionally, the controller 200 may pre-store formulas characterizing the corresponding relationship between the average pressure and the motor speed, such as the calculation formula of the motor speed, so that when it is necessary to adjust the transmission speed of the manipulator 100, the motor speed corresponding to the average pressure can be calculated in a timely manner according to the formula, and the transmission speed can be adjusted to ensure the real-time nature of the adjustment process. Optionally, the calculation formula of the motor speed is: Fx = k * n + 1, where Fx represents the average pressure, n represents the motor speed, k represents the adjustment coefficient, and the symbol * represents multiplication; the value of the adjustment coefficient k can be set according to factors such as the motor type and / or configuration corresponding to the manipulator 100, and can take values such as 0.066.

[0060] In one example, the controller 200 is further configured to obtain the pressure range between the maximum value and the minimum value in the pressure information on either side of the central axis of the carrier plate. When the pressure range is greater than or equal to a preset range threshold, the controller 200 controls the manipulator 100 to return the wafer to the calibration platform. The above range threshold can be set according to the force characteristics of the wafer at each measurement point. If the pressure range is less than the range threshold, it indicates that the current force on the wafer is relatively uniform, and the possibility of the wafer slipping during the transmission process by the manipulator 100 is relatively low, and the risk is relatively small. Here, the controller 200 can control the manipulator 100 to continue transmitting the wafer in the current state; when the pressure range is greater than or equal to the range threshold, it indicates that the current force on the wafer has uneven characteristics, and the possibility of slipping is relatively large, and the risk is relatively large. Here, the controller 200 controls the manipulator 100 to return the wafer to the calibration platform, so that the calibration platform adjusts the position of the wafer relative to the carrier plate, and the carrier plate re-adsorbs the wafer after the position adjustment to reduce the risk of the wafer slipping during the subsequent transmission process.

[0061] Optionally, after the carrier plate of the manipulator 100 re-adsorbs the wafer, each sensor unit continues to detect the pressure information of the corresponding measurement point and sends the corresponding pressure information to the controller 200. The controller can also return to execute the process of obtaining the pressure range between the maximum value and the minimum value in the pressure information on either side of the central axis of the carrier plate, and when the pressure range is greater than or equal to the preset range threshold, control the manipulator 100 to return the wafer to the calibration platform until the controller 200 detects that the pressure range is stably less than the range threshold. This can avoid situations such as wafer dropping and / or loss during the transmission process of the manipulator, and further ensure the stability of the wafer during transmission.

[0062] In one embodiment, the above wafer transfer device further includes an AD conversion module; the AD conversion module is connected between each sensor unit and the controller 200 to convert the analog signal output by the sensor unit into a digital signal and then send the pressure information represented by the digital signal to the controller 200. In this way, the controller 200 can directly read and process the pressure information represented by the digital signal, which can improve the processing efficiency.

[0063] In one example, the wafer transfer device may further include other components such as a speed measurement module, so that the controller can obtain more accurate and comprehensive transfer parameters and improve the effect of transfer control based on these transfer parameters.

[0064] In one example, each group of pressure sensors 110 may form a pressure detection system, and the structure of the wafer transfer device may refer to Figure 5 as shown, including a manipulator 100, a controller 200, a pressure detection system 120, an AD conversion module 221, a speed measurement module 222, a pulse width modulation module 223, a vacuum adsorption mechanism 224, and so on. Optionally, the speed measurement module 222 may be based on the speed measurement scheme of the vacuum hand motor, and use the rotor position detection based on the switch-type Hall sensor to correspond to the rotor speed, so as to send the rotor speed to the controller 200, so that the controller 200 further monitors and / or controls the transfer process of the manipulator 100 according to the rotor speed; among them, the three-phase Hall sensors in the above switch-type Hall sensors are mutually 120° apart, which can provide the position signals of six motor rotors and have high measurement accuracy.

[0065] For the above wafer transfer device, when the pressure information measured by at least one group of pressure sensors does not match, the controller 200 can control the manipulator 100 to return the wafer to the calibration platform, so that the calibration platform adjusts the position of the wafer relative to the carrier plate to ensure the uniformity and stability of the pressure information received by the wafer during the subsequent wafer transfer process; when transferring the wafer, the controller 200 can also adjust the transfer speed of the manipulator 100 to the speed matching the pressure average value when the pressure information measured by any sensor unit is greater than or equal to the preset pressure value, which can reduce the risk of problems such as uneven force, deformation, and / or position offset caused by excessive pressure on the wafer, and further improve the reliability of the wafer transfer process; in addition, the controller 200 can also control the manipulator 100 to return the wafer to the calibration platform when the pressure range difference is greater than or equal to the range difference threshold, so that the calibration platform can timely adjust the position of the wafer relative to the carrier plate and reduce the probability of the wafer sliding. It can be seen that the above wafer transfer device can timely adjust the position of the wafer relative to the carrier plate, reasonably control the wafer transfer speed, and improve the stability of the wafer transfer process in many aspects.

[0066] The present application provides a wafer transfer method in a second aspect, which is applied to the wafer transfer device described in any of the above embodiments. The wafer transfer method includes:

[0067] When the carrier plate holds the wafer, obtain the pressure information measured by at least one group of sensor units;

[0068] When the pressure information measured by at least one group of sensor units does not match, control the manipulator to transfer the held wafer back to the calibration platform. After adjusting the position of the wafer relative to the carrier plate on the calibration platform, the manipulator adsorbs the wafer again for transfer.

[0069] In one embodiment, the wafer transfer device includes multiple groups of pressure sensors; the wafer transfer method further includes: when the manipulator transfers the wafer and the pressure information measured by any one sensor unit is greater than or equal to a preset pressure value, obtain the pressure average value according to the pressure information measured by each sensor unit, calculate the motor speed corresponding to the manipulator according to the pressure average value, and output a pulse width control signal corresponding to the motor speed to the pulse width modulation module, so that the pulse width modulation module outputs corresponding control pulses to the manipulator according to the pulse width control signal.

[0070] Optionally, the above wafer transfer method further includes: obtaining the pressure range between the maximum value and the minimum value of the pressure information on either side of the central axis of the carrier plate, and when the pressure range is greater than or equal to a preset range threshold, controlling the manipulator to transfer the wafer back to the calibration platform.

[0071] Optionally, the calculation formula of the above motor speed includes: Fx = k * n + 1, where Fx represents the pressure average value, n represents the motor speed, k represents the adjustment coefficient, and the symbol * represents multiplication.

[0072] In one example, apply the above wafer transfer method to Figure 5 the wafer transfer device shown in Figure 6 shown. The working process of the wafer transfer device can be referred to

[0073] S511, the vacuum adsorption mechanism 224 adsorbs the wafer on the surface of the carrier plate;

[0074] S512, the controller 200 obtains the pressure information measured by each group of pressure sensors 110 in the pressure detection system 120 through the AD conversion module 221;

[0075] S513, the controller 200 determines whether the pressure information measured by each sensor unit in each group of pressure sensors 110 matches. If so, execute step S514; if not, execute step S519;

[0076] S514, the controller 200 determines that the relative position of the wafer relative to the carrier plate has no offset;

[0077] In S515, the controller 200 starts the motor corresponding to the manipulator 100 at a set transmission speed, and controls the manipulator 100 to transfer the adsorbed wafer; wherein the initial speed of the set transmission speed is the initial transmission speed;

[0078] In S516, the controller 200 determines whether the pressure information measured by the sensor unit is less than a preset pressure value. If not, it executes step S521; if so, it executes step S517;

[0079] In S517, the controller 200 determines whether the pressure difference on either side of the central axis of the carrier plate is less than the difference threshold. If so, it executes step S518; if not, it executes step S519;

[0080] In S518, the controller 200 determines that the current transmission is risk-free and continues to transfer the wafer;

[0081] In S519, the controller 200 determines that the position of the wafer has shifted and executes step S520;

[0082] In S520, the controller 200 controls the manipulator 100 to return the wafer to the calibration platform for calibration, and returns to execute step S511;

[0083] In S521, the controller 200 determines that the current transmission speed is inappropriate, obtains the pressure mean value according to the pressure information measured by each sensor unit, calculates the motor speed corresponding to the manipulator 100 according to the pressure mean value, updates the set transmission speed according to the motor speed, returns to execute step S515, so that the controller 200 outputs a pulse width control signal corresponding to the motor speed to the pulse width modulation module 223, so that the pulse width modulation module 223 outputs corresponding control pulses to the manipulator 100 according to the pulse width control signal, and adjusts the transmission speed of the manipulator 100 to the speed matching the pressure mean value.

[0084] In the wafer transfer method provided in this example, before the robot 100 transfers the wafer, when the pressure information measured by at least one set of pressure sensors does not match, the controller 200 can control the robot 100 to return the wafer to the calibration platform, enabling the calibration platform to adjust the relative position between the wafer and the carrier plate in a timely manner, and ensuring the uniformity and stability of the pressure information when the wafer is adsorbed on the surface of the carrier plate. After the robot 100 transfers the wafer, when the pressure information measured by any one of the sensor units is greater than or equal to a preset pressure value, the controller 200 can also adjust the transfer speed of the robot 100 to a speed that matches the average pressure, reducing the risk of problems such as uneven stress, deformation, and / or position offset caused by excessive pressure on the wafer, and further improving the reliability of the wafer transfer process. In addition, when the pressure range is greater than or equal to a preset range threshold, the controller 200 can also control the robot 100 to return the wafer to the calibration platform, enabling the calibration platform to adjust the position of the wafer relative to the carrier plate in a timely manner and reducing the probability of the wafer sliding.

[0085] The above wafer transfer method is applied to the wafer transfer device provided in any of the above embodiments, and has all the beneficial effects of the wafer transfer device provided in any of the above embodiments, which will not be elaborated here.

[0086] Although the present application has been shown and described with respect to one or more implementations, those skilled in the art will envision equivalent variations and modifications based on a reading and understanding of this specification and the drawings. The present application includes all such modifications and variations and is limited only by the scope of the appended claims. In particular, with respect to the various functions performed by the above components, the terms used to describe such components are intended to correspond to any component (unless otherwise indicated) that performs the specified function of the component (i.e., it is functionally equivalent), even if it is not structurally equivalent to the disclosed structure that performs the function in the exemplary implementations of the present specification shown herein.

[0087] That is, the above description is only an embodiment of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the content of the specification and drawings of the present application, such as the mutual combination of technical features between various embodiments, or direct or indirect application in other related technical fields, is equally included in the patent protection scope of the present application.

[0088] In addition, in the description of the present application, it should be understood that the orientation or positional relationship indicated by terms such as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present application. In addition, for structural elements with the same or similar characteristics, the present application may use the same or different reference numerals for identification. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more features. In the description of the present application, "a plurality of" means two or more, unless otherwise specifically defined.

[0089] The above description is given so that any person skilled in the art can make and use the present application. In the above description, various details are set forth for purposes of explanation. It should be understood that those of ordinary skill in the art can recognize that the present application can be implemented without the use of these specific details. In other embodiments, well-known structures and processes are not elaborated in detail so as not to obscure the description of the present application with unnecessary details. Therefore, the present application is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features disclosed herein.

Claims

1. A wafer transfer device, characterized in that, The wafer transfer device includes: a manipulator, a controller, at least one set of pressure sensors, and a calibration platform; The manipulator includes a carrier plate, and the surface of the carrier plate is provided with a plurality of grooves. Each groove is axially symmetric about the center of the carrier plate, and the grooves are used to form an adsorption space when the carrier plate carries the wafer; The calibration platform is used to calibrate the relative position between the wafer and the carrier plate; Each set of pressure sensors includes two sensor units. The two sensor units are respectively arranged at the top of the same side wall of the same groove and are axially symmetric about the center axis. When the manipulator carries the wafer, they are used to measure the pressure information received by the wafer at the corresponding measurement points and transmit the pressure information to the controller; The controller is used to control the manipulator to return the carried wafer to the calibration platform when the pressure information measured by at least one set of pressure sensors does not match, and after the calibration platform adjusts the relative position of the wafer, control the manipulator to re-adsorb the wafer.

2. The wafer transfer device according to claim 1, wherein The wafer transfer device includes multiple sets of the pressure sensors; the wafer transfer device further includes a pulse width modulation module. The pulse width modulation module is connected to the controller and the manipulator and is used to output control pulses to the manipulator. The pulse width of the control pulse is proportional to the transfer speed of the manipulator; The controller is further used to, when the manipulator transfers the wafer and the pressure information measured by any one of the sensor units is greater than or equal to a preset pressure value, obtain a pressure average value according to the pressure information measured by each sensor unit, calculate the motor speed corresponding to the manipulator according to the pressure average value, and output a pulse width control signal corresponding to the motor speed to the pulse width modulation module, so that the pulse width modulation module outputs corresponding control pulses to the manipulator according to the pulse width control signal.

3. The wafer transfer device according to claim 1, characterized in that, The controller is further used to obtain the pressure range between the maximum value and the minimum value of the pressure information on any side of the central axis of the carrier plate. When the pressure range is greater than or equal to a preset range threshold, control the manipulator to return the wafer to the calibration platform.

4. The wafer transfer device according to claim 1, wherein The carrier plate has a through hole penetrating the carrier plate; the grooves are parallel to each other and are all communicated with the through hole.

5. The wafer transfer device according to claim 4, characterized in that, The two ends of the carrier plate in the direction of the central axis are respectively a front end and a rear end, and the front end has an arc-shaped edge protruding towards the center of the carrier plate. The groove is arc-shaped, and the two ends of the groove extend to the arc-shaped edge on both sides of the central axis.

6. The wafer transfer device according to claim 5, wherein All the sensor units are arranged in the area between the front end of the carrier plate and the through hole.

7. The wafer transfer device according to claim 4, wherein The wafer transfer device further includes a vacuum adsorption mechanism; the vacuum adsorption mechanism is arranged at the bottom of the carrier plate and is communicated with the through hole.

8. The wafer transfer device according to claim 1, wherein All the sensor units are distributed on the same straight line, and the straight line is perpendicular to the central axis.

9. A wafer transfer method, characterized in that, Applied to the wafer transfer device according to any one of claims 1 to 8, the wafer transfer method includes: When the carrier plate carries the wafer, obtain the pressure information measured by at least one set of the sensor units; When the pressure information measured by at least one group of the sensor units does not match, control the manipulator to send the carried wafer back to the calibration platform, so that after the position of the wafer relative to the carrier plate is adjusted on the calibration platform, the manipulator re-adsorbs the wafer for transmission.

10. The wafer transfer method according to claim 9, wherein The wafer transfer device includes multiple groups of the pressure sensors; the wafer transfer device further includes a pulse width modulation module, the pulse width modulation module is connected to the controller and the manipulator, and is configured to output control pulses to the manipulator, and the pulse width of the control pulses is proportional to the transfer speed of the manipulator; The wafer transfer method further includes: When the manipulator transfers the wafer and the pressure information measured by any one of the sensor units is greater than or equal to a preset pressure value, obtain a pressure average value according to the pressure information measured by each of the sensor units, calculate the motor rotation speed corresponding to the manipulator according to the pressure average value, and output a pulse width control signal corresponding to the motor rotation speed to the pulse width modulation module, so that the pulse width modulation module outputs corresponding control pulses to the manipulator according to the pulse width control signal; And / or, obtain the pressure range between the maximum value and the minimum value of the pressure information on either side of the central axis of the carrier plate, and when the pressure range is greater than or equal to the preset range threshold, control the manipulator to send the wafer back to the calibration platform.

11. The wafer transfer method according to claim 10, wherein, The calculation formula of the motor rotation speed includes: Fx = k * n + 1, wherein, Fx represents the pressure average value, n represents the motor rotation speed, k represents the adjustment coefficient, and the symbol * represents multiplication.

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