Wafer cleaning system

Abstract

The utility model discloses a wafer cleaning system, which is characterized in that a PLC (Programmable Logic Controller) control system calculates the planeness of a wafer according to position values measured by a first distance sensor, a second distance sensor and a third distance sensor, so that the planeness of the wafer is monitored in real time, and the risk that the wafer rotates at a high speed and flies out is effectively prevented; the PLC control system is matched with the top cleaning rod and the bottom cleaning pipe to perform rapid centrifugal cleaning and centrifugal drying on two sides of the wafer, so that the wafer is effectively prevented from inclining to fly out fragments, and the problems that the wafer inclines due to high-speed centrifugal cleaning on two sides of the wafer in the wafer cleaning process and the wafer is damaged are solved. And because the wafer is not horizontal, the wafer is thrown out, and the wafer is broken.

Description

Technical Field

[0001] The utility model relates to the technical field of wafer process, in particular to a wafer cleaning system. Background Art

[0002] In the chip manufacturing process, after cutting the wafer (wafer for short), the grinding process begins. The wafer is ground to reduce saw marks and surface damage on the front and back sides, while thinning the wafer and helping to release the stress accumulated during the cutting process. After grinding, the etching and cleaning process begins. A mixed cleaning solution of sodium hydroxide, acetic acid and nitric acid is used to reduce damage and cracks caused during the grinding process. The key cleaning process is to perform high-speed centrifugal double-sided cleaning on the polished wafer. During the cleaning process, due to centrifugal force and the bottom spraying of cleaning solution, the wafer may not be level, hit the wafer fixing column, deviate, or even fly out, resulting in the risk of wafer fragmentation. Therefore, in the wafer cleaning process, it is a technical problem that technicians in this field need to solve urgently to prevent the wafer from tilting due to high-speed centrifugal double-sided cleaning of the wafer, and the wafer from being thrown out due to the non-level wafer, resulting in wafer fragmentation. Utility Model Content

[0003] The utility model provides a wafer cleaning system for solving the technical problems that wafer tilting is caused by high-speed centrifugal double-sided cleaning of wafers during wafer cleaning, and wafer fragments are caused by wafer being thrown out due to non-level wafers.

[0004] In view of this, the utility model provides a wafer cleaning system, including a wafer mounting plate, a wafer mounting column, a rotating table, a sensor support, a first distance sensor, a second distance sensor, a third distance sensor, a top cleaning rod, a cleaning rod support, a bottom cleaning pipe and a PLC control system;

[0005] The wafer mounting column is a convex column, and there are multiple wafer mounting columns, which are fixed on the wafer mounting plate at equal intervals;

[0006] The wafer mounting plate is mounted on the top of the rotating table, and the wafer mounting plate is movably connected to the rotating table;

[0007] One end of the bottom cleaning pipe passes through the rotating table and the bottom of the wafer mounting plate in a vertical direction, and the other end of the bottom cleaning pipe is connected to a cleaning liquid container;

[0008] The top cleaning rod is an L-shaped structure, the top cleaning rod is installed on the cleaning rod support, the height of the top cleaning rod is higher than the wafer mounting column, and the top cleaning rod is provided with a nozzle;

[0009] The sensor support is an L-shaped structure, the end of the top crossbar of the sensor support is a three-claw end, the three-claw ends are distributed at 120-degree intervals, the center point of the three-claw end is aligned with the center point of the wafer mounting plate, and the length of the three-claw end is the radius of the wafer mounting plate;

[0010] The first distance sensor, the second distance sensor and the third distance sensor are movably mounted on the ends of the three claws respectively;

[0011] The PLC control system is respectively connected with the rotating platform, the first distance sensor, the second distance sensor, the third distance sensor, the top cleaning rod and the bottom cleaning pipe.

[0012] Optionally, the top cleaning rod is movably connected to the cleaning rod support.

[0013] Optionally, a sliding mechanism is provided on the cleaning rod support, the top cleaning rod is mounted on the sliding mechanism, and the sliding mechanism is connected to the PLC control system.

[0014] Optionally, the sliding mechanism includes a slide rail and a slider, the slide rail is mounted on the cleaning rod support, the slider is mounted on the slide rail, and the top cleaning rod is mounted on the slider.

[0015] Optionally, a human-computer interaction interface is also included, and the human-computer interaction interface is connected to the PLC control system.

[0016] Optionally, the human-computer interaction interface is a touch screen.

[0017] Optionally, a manipulator is also included, and the manipulator is connected to a PLC control system.

[0018] Optionally, the top cleaning rod and the bottom cleaning pipe are respectively provided with electric control valves, and the electric control valves are connected to the PLC control system.

[0019] Optionally, the electrically controlled valve is a suck-back valve.

[0020] Optionally, the number of wafer mounting posts is 6.

[0021] It can be seen from the above technical solutions that the wafer cleaning system provided by the utility model has the following advantages:

[0022] The utility model provides a wafer cleaning system, in which a PLC control system calculates the wafer flatness according to the position values ​​measured by the first distance sensor, the second distance sensor and the third distance sensor, thereby monitoring the wafer flatness in real time, effectively preventing the risk of the wafer flying out during high-speed rotation; the PLC control system cooperates with the top cleaning rod and the bottom cleaning pipe to perform rapid centrifugal cleaning and centrifugal drying on both sides of the wafer, effectively preventing the wafer from tilting and flying out fragments, and solving the technical problems of wafer tilting caused by high-speed centrifugal double-sided cleaning of the wafer during the wafer cleaning process, and wafer fragments caused by the wafer being thrown out due to the non-level wafer.

[0023] At the same time, the wafer cleaning system provided by the utility model has a top cleaning rod slidably installed on a cleaning rod support, which can adapt to the cleaning range of wafers of different sizes and specifications and can adapt to different application scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 This is a structural schematic diagram of a wafer cleaning system provided in the utility model;

[0026] Wherein, the accompanying drawings are marked as follows:

[0027] 1. First distance sensor; 2. Second distance sensor; 3. Third distance sensor; 4. Sensor support; 5. Top cleaning rod; 6. Cleaning rod support; 7. Rotating table; 8. Bottom cleaning pipe; 9. PLC control system; 10. Human-computer interaction interface; 11. Chip; 12. Chip mounting plate; 13. Chip mounting column. DETAILED DESCRIPTION

[0028] In order to enable those skilled in the art to better understand the solution of the utility model, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is only a part of the embodiment of the utility model, not all of the embodiments. Based on the embodiment of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0029] For easier understanding, see Figure 1 The utility model provides an embodiment of a wafer cleaning system, including a wafer mounting plate 12, a wafer mounting column 13, a rotating table 7, a sensor support 4, a first distance sensor 1, a second distance sensor 2, a third distance sensor 3, a top cleaning rod 5, a cleaning rod support 6, a bottom cleaning pipe 8 and a PLC control system 9;

[0030] The wafer mounting column 13 is a convex column, and there are multiple wafer mounting columns 13, which are fixed on the wafer mounting plate 12 at equal intervals.

[0031] The wafer mounting plate 12 is mounted on the top of the rotating platform 7, and the wafer mounting plate 12 is movably connected to the rotating platform 7;

[0032] One end of the bottom cleaning pipe 8 passes through the rotating table 7 and the bottom of the wafer mounting plate 12 in the vertical direction, and the other end of the bottom cleaning pipe 8 is connected to the cleaning liquid container;

[0033] The top cleaning rod 5 is an L-shaped structure, and the top cleaning rod 5 is installed on the cleaning rod support 6. The height of the top cleaning rod 5 is higher than the wafer mounting column 13, and the top cleaning rod 5 is provided with a nozzle;

[0034] The sensor support 4 is an L-shaped structure, the top crossbar end of the sensor support 4 is a three-claw end, the three-claw ends are distributed at 120-degree intervals, the center point of the three-claw end is aligned with the center point of the wafer mounting plate 12, and the length of the three-claw end is the radius of the wafer mounting plate 12;

[0035] The first distance sensor 1, the second distance sensor 2 and the third distance sensor 3 are movably mounted on the ends of the three claws respectively;

[0036] The PLC control system 9 is connected to the rotating table 7, the first distance sensor 1, the second distance sensor 2, the third distance sensor 3, the top cleaning rod 5 and the bottom cleaning pipe 8 respectively.

[0037] It should be noted that the wafer mounting column 13 is a convex column. Under the action of multiple wafer mounting columns 13, the wafer can be clamped on the wafer mounting plate 12. The number of wafer mounting columns 13 is preferably 6, which can achieve the best fixation of the wafer 11 at a relatively low cost. One end of the bottom cleaning pipe 8 passes through the rotating table 7 and the bottom of the wafer mounting plate 12 in the vertical direction, and the other end of the bottom cleaning pipe 8 is connected to the cleaning liquid container. Under the control of the PLC control system 9, the cleaning liquid flow rate and cleaning time of the bottom cleaning pipe 8 can be controlled in real time according to the cleaning process formula, and the rotation of the rotating table 7 is also controlled by the PLC control system 9. The top cleaning rod 5 is an L-shaped structure, and the top cleaning rod 5 is provided with a nozzle. Under the control of the PLC control system 9, the cleaning liquid flow rate and cleaning time of the top cleaning rod 5 can be controlled in real time according to the cleaning process formula. Therefore, the cooperation of the bottom cleaning pipe 8, the top cleaning rod 5 and the PLC system realizes the double-sided cleaning of the wafer 11. The first distance sensor 1, the second distance sensor 2 and the third distance sensor 3 are used to detect the flatness of the wafer 11, and the first distance sensor 1, the second distance sensor 2 and the third distance sensor 3 can be moved on the three-claw end, and with the cooperation of the rotating table 7, the flatness detection of the wafer 11 in the whole range is realized, which effectively prevents the risk of the wafer 11 tilting and flying out under high-speed rotation to cause fragments. The three-claw end is distributed at intervals of 120 degrees, the center point of the three-claw end is aligned with the center point of the wafer mounting plate 12, and the length of the three-claw end is the radius of the wafer mounting plate 12, so that the full range of the wafer 11 is covered.

[0038] The wafer cleaning system provided by the utility model has a PLC control system 9 that calculates the flatness of the wafer 11 according to the position values ​​measured by the first distance sensor 1, the second distance sensor 2 and the third distance sensor 3, thereby monitoring the flatness of the wafer 11 in real time, and effectively preventing the risk of the wafer 11 flying out due to high-speed rotation. The PLC control system 9 cooperates with the top cleaning rod 5 and the bottom cleaning tube 8 to perform rapid centrifugal cleaning and centrifugal drying on both sides of the wafer 11, effectively preventing the wafer 11 from tilting and flying out fragments, and solving the technical problems of the wafer tilting caused by high-speed centrifugal double-sided cleaning of the wafer during the wafer cleaning process, and the wafer being thrown out due to the non-level wafer causing wafer fragments.

[0039] In one embodiment, the top cleaning rod 5 is movably connected to the cleaning rod support 6. The top cleaning rod 5 is set to be movable, which can adapt to the cleaning process of wafers 11 of different sizes and specifications, and has flexibility. Specifically, a sliding mechanism can be set on the cleaning rod support 6, and the top cleaning rod 5 is installed on the sliding mechanism, and the sliding mechanism is connected to the PLC control system 9. The sliding mechanism includes a slide rail and a slider, the slide rail is installed on the cleaning rod support 6, the slider is installed on the slide rail, and the top cleaning rod 5 is installed on the slider. The sliding mechanism mainly drives the top cleaning rod 5 to move left and right on the cleaning rod support 6 to ensure that the top cleaning rod 5 can pass the rotation center of the wafer 11, and the telescopic position and speed of the top cleaning rod 5 can be adjusted in real time according to the cleaning formula parameters.

[0040] In one embodiment, the wafer cleaning system further includes a human-machine interaction interface 10, which is connected to the PLC control system 9. The user can input control instructions through the human-machine interaction interface 10, and the PLC control system 9 executes the instructions to control the corresponding terminal to perform corresponding actions, thereby improving the human-machine interaction capability of the wafer cleaning system. The human-machine interaction interface 10 is preferably a touch screen.

[0041] In one embodiment, the wafer cleaning system further includes a manipulator connected to the PLC control system 9. The manipulator is used to clamp the wafer 11 to be cleaned and install it on the wafer mounting plate 12, and clamp it through the wafer mounting posts 13 on the wafer mounting plate 12. The manipulator is also used to remove the cleaned wafer 11 from the wafer mounting plate 12 and place it at a designated location after the wafer 11 is cleaned, thereby avoiding contamination and damage to the wafer 11 caused by manual loading and unloading.

[0042] In one embodiment, the top cleaning rod 5 and the bottom cleaning pipe 8 are respectively provided with an electric control valve, which is connected to the PLC control system 9 and is a back-sucking valve. The PLC control system 9 controls the circulation of the cleaning liquid in the top cleaning rod 5 and the bottom cleaning pipe 8 by controlling the opening and closing of the electric control valve. Configuring the electric control valve as a back-sucking valve can prevent the liquid from dripping after the valve is closed, causing secondary contamination of the wafer 11.

[0043] The working principle of the wafer cleaning system provided in the utility model can be described as follows:

[0044] After the wafer 11 is moved to the wafer mounting plate 12 by the robot, the first distance sensor 1, the second distance sensor 2 and the third distance sensor 3 simultaneously measure the distance from the upper surface of the wafer 11 to the distance sensor. When the values ​​of the three groups of sensors are equal, it is determined that the wafer 11 is level to prevent the lens from being thrown out of the spin-drying plate due to the unevenness of the wafer 11. Then, the fitting center of the circle of the three points on the edge of the wafer 11 is measured, and the PLC control system 9 is used to calculate whether the center position of the wafer 11 coincides with the center of the wafer mounting plate 12, which effectively prevents vibration and impact during high-speed rotation from causing fragments. If the wafer 11 is offset or uneven, the distance sensor will transmit the offset value to the PLC control system 9. After the algorithm calculation of the PLC control system 9, the deviation position is transmitted to the robot to adjust the position of the wafer 11, and the wafer can be placed again. When the measurement is completed, the cleaning process begins. Cleaning begins according to the time, speed, rotation speed, flow rate and other parameters set in the process. The PLC control system 9 controls the top cleaning rod 5 and the bottom medicine tube to start spraying the cleaning liquid. Various cleaning liquids are circulated for cleaning. After various cleaning liquids are cleaned according to the process formula, the PLC controls the rotating table 7 to high-speed centrifugal drying. After the drying is completed, the distance sensor will measure the position and horizontal situation of the chip 11 again to prevent the robot from taking the chip out of position and causing the chip to be placed offset. After the measurement is completed, the robot will remove the chip and then install the next chip to be washed, and repeat this cycle.

[0045] The terms "first", "second", "third", "fourth", etc. (if any) in the specification of the utility model are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the utility model described here can be implemented in an order other than those illustrated or described here, for example. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0046] As described above, the above embodiments are only used to illustrate the technical solutions of the utility model, rather than to limit it. Although the utility model has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments can still be modified, or some of the technical features can be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the utility model.

Claims

1. A wafer cleaning system, characterized in that: It includes a wafer mounting plate, a wafer mounting column, a rotating table, a sensor support, a first distance sensor, a second distance sensor, a third distance sensor, a top cleaning rod, a cleaning rod support, a bottom cleaning pipe and a PLC control system; The wafer mounting column is a convex column, and there are multiple wafer mounting columns, which are fixed on the wafer mounting plate at equal intervals; The wafer mounting plate is mounted on the top of the rotating table, and the wafer mounting plate is movably connected to the rotating table; One end of the bottom cleaning pipe passes through the rotating table and the bottom of the wafer mounting plate in a vertical direction, and the other end of the bottom cleaning pipe is connected to a cleaning liquid container; The top cleaning rod is an L-shaped structure, the top cleaning rod is installed on the cleaning rod support, the height of the top cleaning rod is higher than the wafer mounting column, and the top cleaning rod is provided with a nozzle; The sensor support is an L-shaped structure, the end of the top crossbar of the sensor support is a three-claw end, the three-claw ends are distributed at 120-degree intervals, the center point of the three-claw ends is aligned with the center point of the wafer mounting plate, and the length of the three-claw ends is the radius of the wafer mounting plate; The first distance sensor, the second distance sensor and the third distance sensor are movably mounted on the ends of the three claws respectively; The PLC control system is respectively connected with the rotating platform, the first distance sensor, the second distance sensor, the third distance sensor, the top cleaning rod and the bottom cleaning pipe.

2. The wafer cleaning system according to claim 1, characterized in that: The top cleaning rod is movably connected to the cleaning rod support.

3. The wafer cleaning system according to claim 2, characterized in that: A sliding mechanism is arranged on the cleaning rod support, the top cleaning rod is installed on the sliding mechanism, and the sliding mechanism is connected with the PLC control system.

4. The wafer cleaning system according to claim 3, characterized in that: The sliding mechanism comprises a sliding rail and a sliding block, the sliding rail is mounted on the cleaning rod support, the sliding block is mounted on the sliding rail, and the top cleaning rod is mounted on the sliding block.

5. The wafer cleaning system according to claim 1, characterized in that: It also includes a human-machine interaction interface, which is connected with the PLC control system.

6. The wafer cleaning system according to claim 5, characterized in that: The human-computer interaction interface is a touch screen.

7. The wafer cleaning system according to claim 1, characterized in that: It also includes a manipulator, which is connected to a PLC control system.

8. The wafer cleaning system according to claim 1, characterized in that: The top cleaning rod and the bottom cleaning pipe are respectively provided with electric control valves, which are connected to the PLC control system.

9. The wafer cleaning system according to claim 8, characterized in that: The electrically controlled valve is a suck-back valve.

10. The wafer cleaning system according to claim 1, characterized in that: The number of wafer mounting posts is 6.

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