Wafer cleaning machine and fan filter unit fault detection circuit

Abstract

The invention discloses a wafer cleaning machine and a fan filter unit fault detection circuit. The fan filter unit fault detection circuit is applied to the cleaning machine. The cleaning machine comprises an anemograph, a fan filter unit, an exhaust control circuit and a first alarm unit. The fan filtering unit is used for generating air, the anemograph is used for detecting the air outlet speed of the fan filtering unit, and the air exhaust control circuit is used for controlling whether the first alarm unit gives an alarm or not according to the air outlet speed of the fan filtering unit; the fan filter unit fault detection circuit is connected with the anemograph and the air exhaust control circuit, and is used for obtaining a detection result of the anemograph, determining whether the fan filter unit has a fault based on the detection result, and sending the fan filter unit fault detection circuit to the air exhaust control circuit when the fan filter unit has the fault. And the air exhaust control circuit triggers the first alarm unit to give an alarm. By adopting the scheme, fault monitoring can be carried out on the fan filter unit in the cleaning machine, so that the influence on the wafer quality and a machine table is reduced.

Description

Technical Field

[0001] This invention relates to the field of cleaning machines, specifically to a wafer cleaning machine and a fault detection circuit for the fan filter unit. Background Technology

[0002] Throughout the manufacturing process, wafers undergo repeated photolithography, etching, ion implantation, deposition, and polishing. Each step leaves behind particles, metallic impurities, organic matter, oxide layers, or polymer residues. If these contaminants are not removed in time, subsequent processes will experience a sharp drop in yield, device failure, or even the scrapping of the entire batch. Therefore, during wafer manufacturing, it is necessary to clean the wafer surface to remove contaminants.

[0003] A wet cleaning machine is a type of wafer cleaning machine that performs wet cleaning on the surface of wafers. The machine sprays cleaning fluid onto the wafer surface, which evaporates upwards, potentially contaminating the top of the machine. To reduce contamination of the top of the machine, wet cleaning machines typically include a fan filter unit (FFU). This unit draws air from the top of the machine, filters the air, and then blows it downwards evenly, creating effective positive air pressure. This positive air pressure forces the evaporating cleaning fluid to the bottom of the machine, where it can be discharged through the exhaust duct.

[0004] However, the existing wet cleaning machine's internal fan filter unit does not alarm when it trips or stops running, which prevents users from taking timely measures, ultimately affecting wafer quality and corroding the machine. Summary of the Invention

[0005] The problem this invention aims to solve is: how to monitor the faults of the blower filter unit inside the cleaning machine in order to reduce the impact on wafer quality and the machine itself.

[0006] To address the aforementioned problems, this invention provides a fan filter unit fault detection circuit. This circuit is applied within a cleaning machine, which includes an anemometer, a fan filter unit, an exhaust control circuit, and a first alarm unit. The fan filter unit generates airflow, the anemometer detects the outlet airflow speed of the fan filter unit, and the exhaust control circuit controls whether the first alarm unit sounds an alarm based on the outlet airflow speed of the fan filter unit.

[0007] The fan filter unit fault detection circuit is connected to the anemometer and the exhaust control circuit. It is used to obtain the detection result of the anemometer, determine whether the fan filter unit is faulty based on the detection result, and trigger the first alarm unit through the exhaust control circuit when the fan filter unit is faulty.

[0008] In one possible embodiment, the fan filter unit fault detection circuit includes:

[0009] A fault detection unit is used to acquire the detection results of the anemometer and determine whether the fan filter unit is faulty based on the detection results.

[0010] And a first triggering unit, connected to the fault detection unit and the exhaust control circuit, is used to trigger the first alarm unit to sound an alarm through the exhaust control circuit when the fan filter unit fails.

[0011] In one possible embodiment, the fault detection unit includes:

[0012] The first data receiving subunit is connected to the anemometer and is used to receive the detection results of the anemometer.

[0013] And a comparison subunit, connected to the first data receiving subunit, is used to compare the detection result of the anemometer with the lower limit threshold of the outlet wind speed to determine whether the fan filter unit is faulty.

[0014] In one possible embodiment, the first triggering unit includes a first relay; the first relay includes a first coil, a first diode, and a first switch; the first coil and the first diode are connected in parallel; one end of the first coil is connected to the fault detection unit; and the first switch is connected to the exhaust control circuit.

[0015] In one possible embodiment, the exhaust control circuit includes: an exhaust control unit, a first switching unit, a second switching unit, and a second triggering unit; wherein:

[0016] The exhaust control unit is connected to the first switch unit and the second switch unit, and is used to acquire the exhaust wind speed and control the alarm triggering unit through the first switch unit or the second switch unit.

[0017] The second triggering unit is connected to the first switch unit and the second switch unit, and is used to control the first alarm unit to sound an alarm when the corresponding conditions are met.

[0018] In one possible embodiment, the exhaust control unit includes:

[0019] The second data receiving subunit is used to obtain the exhaust air velocity;

[0020] The first control subunit is connected to the second data receiving subunit and the first switch unit, and is used to connect the second trigger unit through the first switch unit when the exhaust wind speed reaches the upper limit threshold of the outlet wind speed.

[0021] The second control subunit, connected to the second data receiving subunit and the second switch unit, is used to connect the second trigger unit through the second switch unit when the anemometer's detection result reaches the lower limit threshold of the exhaust wind speed.

[0022] In one possible embodiment, the first switching unit is implemented using a second relay; the second relay includes: a second coil, a second diode, and a second switch; the second coil and the second diode are connected in parallel; one end of the second coil is connected to the exhaust control unit, and the other end is connected to the second switch; the other end of the second switch is connected to the second trigger unit.

[0023] In one possible embodiment, the second switching unit is implemented using a third relay; the third relay includes: a third coil, a third diode, and a third switch; the third coil and the third diode are connected in parallel; one end of the third coil is connected to the exhaust control unit, and the other end is connected to the third switch; the other end of the third switch is connected to the second triggering unit.

[0024] In one possible embodiment, the second triggering unit is implemented using a fourth relay; the fourth relay includes: a fourth coil, a fourth diode, and a fourth switch; the fourth diode is connected in parallel with the fourth coil; one end of the fourth coil is connected to the first alarm unit.

[0025] In one possible embodiment, the fourth relay further includes: a timer for timing the duration of the low wind speed of the fan filter unit; and a fourth coil for controlling the fourth switch to operate when the duration of the low wind speed of the fan filter unit reaches a preset duration.

[0026] In one possible embodiment, the fan filter unit fault detection circuit further includes a second alarm unit connected to the fault detection unit, used to issue an alarm when the fan filter unit malfunctions.

[0027] This invention also provides a wafer cleaning machine, which includes: a fan filter unit fault detection circuit of any of the above-mentioned types.

[0028] Compared with the prior art, the technical solution of the embodiments of the present invention has the following advantages:

[0029] By applying the solution of this invention, a fault detection circuit for the fan filter unit is set up. Since this circuit is connected to the anemometer and exhaust control circuit, it can determine whether the fan filter unit is faulty based on the anemometer's detection results. When a fault occurs, the exhaust control circuit triggers the first alarm unit, thus enabling timely alarms when the fan filter unit trips or stops operating. This allows users to take immediate measures to avoid affecting wafer quality and corroding the equipment. Furthermore, this fault detection circuit is connected to the existing anemometer and exhaust control circuit inside the cleaning machine. By utilizing existing components in the cleaning machine to implement the fan alarm, the cost of the fan alarm can be reduced, and modifications to the cleaning machine structure can be minimized, achieving maximum compatibility with existing cleaning machine structures. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the structure of a cleaning machine according to an embodiment of the present invention;

[0031] Figure 2 This is a schematic diagram of the structure of a fan filter unit fault detection circuit in an embodiment of the present invention;

[0032] Figure 3 This is a schematic diagram of the circuit structure of a fan filter unit fault detection circuit and an exhaust control circuit in an embodiment of the present invention;

[0033] Figure 4 This is a schematic diagram of the structure of an exhaust control circuit in an embodiment of the present invention. Detailed Implementation

[0034] The existing wet cleaning machine's internal fan filter unit does not alarm when it trips or stops running, which results in the lack of effective positive air pressure inside the machine. Consequently, the gas generated by the evaporation of the cleaning fluid inside the machine cannot be discharged through the exhaust channel in time, leading to excessive levels of the gas generated by the evaporation of the cleaning fluid inside the machine.

[0035] Taking the cleaning solution as an example, when the acid gas generated by the evaporation of the acidic liquid exceeds the standard, it will cause the aluminum layer on the front side of the wafer to oxidize and produce white acid spots, affecting the quality of the wafer. On the other hand, it will corrode the top of the machine and shorten the life of the machine.

[0036] To address this problem, the present invention provides a fault detection circuit for a fan filter unit. This circuit not only provides timely alarms when the fan filter unit trips or stops operating, but also reduces the cost of fan alarms and minimizes modifications to the cleaning machine structure, achieving maximum compatibility with existing cleaning machine structures.

[0037] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0038] Reference Figure 1 This invention provides a wafer cleaning machine 10, which may include: an anemometer 11, a fan filter unit 12, an exhaust control circuit 13, a first alarm unit 14, and a fan filter unit fault detection circuit 15. Wherein:

[0039] The fan filter unit 11 is used to generate air;

[0040] The anemometer 12 is used to detect the outlet air velocity of the fan filter unit 11;

[0041] The exhaust control circuit 13 is used to control whether the first alarm unit 14 alarms based on the exhaust air speed of the fan filter unit 11.

[0042] The fan filter unit fault detection circuit 15 is connected to the anemometer 12 and the exhaust control circuit 13. It is used to obtain the detection result of the anemometer 12, determine whether the fan filter unit 11 is faulty based on the detection result, and trigger the first alarm unit 14 to alarm when the fan filter unit 11 is faulty through the exhaust control circuit 13.

[0043] Specifically, the fan filter unit 11 can be located above the wafer cleaning machine 10. The fan filter unit 11 can draw in air from above the wafer cleaning machine 10, filter the drawn-in air, and then blow it evenly into the machine 10. The anemometer 12 can be located near the air outlet of the fan filter unit 11, thereby detecting the air velocity at the outlet of the fan filter unit 11 and outputting an electrical signal characterizing the air velocity detection result.

[0044] The exhaust control circuit 13 is electrically connected to the wind speed sensor in the exhaust duct, which can obtain the detection result of the exhaust wind speed in the exhaust duct, and control whether the first alarm unit 14 alarms based on the detection result of the exhaust wind speed. For example, when the exhaust wind speed is too high or too low, the first alarm unit 14 can be triggered to alarm, and the alarm can promptly notify the user to adjust the exhaust power, etc.

[0045] Unlike existing wafer cleaning machines, the wafer cleaning machine in this embodiment of the invention also includes a fan filter unit fault detection circuit 15. This circuit can be connected to an anemometer 12 and an exhaust control circuit 13, thereby determining whether the fan filter unit 11 is faulty based on the anemometer 12's detection results, thus achieving fault detection of the fan filter unit 11. Furthermore, when the fan filter unit 11 malfunctions, the existing exhaust control circuit 13 triggers the first alarm unit 14. The fan filter unit fault detection circuit 15 mainly utilizes the existing wafer cleaning machine structure to achieve fan fault detection and alarm, effectively reducing implementation costs and providing better compatibility with existing cleaning machine structures.

[0046] In specific implementations, the fault detection circuit 15 of the fan filter unit can be implemented in various structures, and no restrictions are imposed here.

[0047] In one embodiment of the present invention, reference is made to... Figure 2 The fan filter unit fault detection circuit 15 may include: a fault detection unit 151 and a first trigger unit 152. Wherein:

[0048] The fault detection unit 151 is used to acquire the detection result of the anemometer 12 and determine whether the fan filter unit 11 is faulty based on the detection result.

[0049] The first triggering unit 152 is connected to the fault detection unit 151 and the exhaust control circuit 13, and is used to trigger the first alarm unit 14 to alarm through the exhaust control circuit 13 when the fan filter unit 11 fails.

[0050] In a specific implementation, the fault detection unit 151 can determine whether the fan filter unit 11 is faulty by comparing the outlet air speed with a preset air speed threshold.

[0051] In practical applications, before the fan filter unit 11 trips or stops operating, the air velocity of the fan filter unit 11 is usually low, or even zero. Therefore, for the fault detection of the fan filter unit 11 tripping or stopping operating, the air velocity can be determined by comparing it with the lower limit threshold of the air velocity.

[0052] Specifically, in one embodiment of the present invention, the fault detection unit 151 may include: a first data receiving subunit 1511 and a comparison subunit 1512. Wherein:

[0053] The first data receiving subunit 1511 is connected to the anemometer 12 and is used to receive the detection results of the anemometer 12;

[0054] The comparison subunit 1512 is connected to the first data receiving subunit 1511 and is used to compare the detection result of the anemometer 12 with the lower limit threshold of the outlet wind speed to determine whether the fan filter unit 11 is faulty.

[0055] Specifically, when the outlet air velocity of the fan filter unit 11 is lower than the lower limit threshold, it can be determined that the fan filter unit 11 is faulty, i.e., a power outage or shutdown has occurred. At this time, the comparison subunit 1512 can output a high-level signal representing the first lower limit comparison result. When the outlet air velocity of the fan filter unit 11 is higher than the lower limit threshold, it can be determined that the fan filter unit 11 has not experienced a power outage or shutdown. At this time, the comparison subunit 1512 can output a high-level signal representing the second lower limit comparison result. The lower limit threshold can be set according to actual conditions.

[0056] In specific implementation, refer to Figure 3 The fault detection unit 151 can be implemented using an integrated circuit chip. In this case, the chip corresponding to the fault detection unit 151 may include: a power supply voltage pin VCC, differential input pins IN- and IN+, differential output pins S1+ and S1- for the first lower limit comparison result, and a ground pin GND.

[0057] The first input pin IN- and the second input pin IN+ are connected to the anemometer 12, thereby receiving the detection results of the anemometer 12. The comparison subunit 1512 compares the detection results of the anemometer 12 with the lower limit threshold of the outlet wind speed, and outputs the differential signal representing the first lower limit comparison result through the differential output pins S1+ and S1-.

[0058] In a specific implementation, the first triggering unit 152 may include a first relay. (Refer to...) Figure 3 Specifically, the first relay may include: a first coil T1, a first diode D1, and a first switch K1; the first coil T1 and the first diode D1 are connected in parallel; one end of the first coil T1 is connected to the fault detection unit 151; and the first switch K1 is connected to the exhaust control circuit 13.

[0059] Specifically, the first diode D1 is connected in reverse parallel across the first coil T1 to absorb reverse high voltage and protect the circuit. When the first coil T1 is energized, it generates a magnetic field that controls the operation of the first switch K1. If the first switch K1 is a normally open switch, the magnetic field generated by the energized coil T1 can close the first switch K1. If the first switch K1 is a normally closed switch, the magnetic field generated by the energized coil T1 can open the first switch K1. When the first coil T1 is de-energized, the magnetic field disappears, and the first switch K1 resets.

[0060] In specific implementation, refer to Figure 3 The a terminal of the first coil T1 can be connected to the S1+ pin in the differential output pin of the first lower limit comparison result, and the b terminal is grounded. In this way, when the pin S1+ outputs a high-level signal representing the first lower limit comparison result, the first coil T1 will be energized, thereby controlling the first switch K1 to operate.

[0061] In other embodiments, refer to Figure 3 The b terminal of the first coil T1 can also be connected to pin S1- in the differential output pin of the first lower limit comparison result, and the a terminal is grounded. In this way, when the pin S1- outputs a high-level signal representing the first lower limit comparison result, the first coil T1 will also be energized, thereby controlling the first switch K1 to operate.

[0062] In an embodiment of the present invention, the first switch K1 can be a normally open switch. When the first coil T1 is energized, the first switch K1 will be closed. When the first coil T1 is de-energized, the first switch K1 will be open.

[0063] Figure 4 This is a schematic diagram of the exhaust control circuit 13 in one embodiment of the present invention. (Refer to...) Figure 4 The exhaust control circuit 13 includes: an exhaust control unit 131, a first switch unit 132, a second switch unit 133, and a second trigger unit 134; wherein:

[0064] The exhaust control unit 131 is connected to the first switch unit 132 and the second switch unit 133, and is used to acquire the exhaust wind speed and control the second trigger unit 134 through the first switch unit 132 or the second switch unit 133.

[0065] The second triggering unit 134 is connected to the first switch unit 132 and the second switch unit 133, and is used to control the first alarm unit 14 to sound an alarm when the corresponding conditions are met.

[0066] In a specific implementation, the exhaust control unit 131 can determine whether the fan filter unit 11 is faulty by comparing the exhaust air speed with a preset air speed threshold.

[0067] Specifically, the exhaust control unit 131 may include: a second data receiving subunit 1311, a first control subunit 1312, and a second control subunit 1313. Wherein:

[0068] The second data receiving subunit 1311 is used to obtain the exhaust air velocity;

[0069] The first control subunit 1312 is connected to the second data receiving subunit 1311 and the first switch unit 132, and is used to connect the second trigger unit 134 through the first switch unit 132 when the exhaust wind speed reaches the upper limit threshold of the outlet wind speed.

[0070] The second control subunit 1313 is connected to the second data receiving subunit 1311 and the second switch unit, and is used to connect the second trigger unit 134 through the second switch unit 132 when the exhaust wind speed reaches the lower limit threshold of the exhaust wind speed.

[0071] The lower limit threshold for exhaust air velocity is used to determine whether the outlet air velocity of the fan filter unit 11 reaches the exhaust alarm level. The lower limit threshold for outlet air velocity is used to determine whether the outlet air velocity of the fan filter unit 11 reaches the alarm level that would cause the fan filter unit 11 to trip or stop operating.

[0072] In a specific implementation, the exhaust control unit 131 can be implemented using an integrated circuit chip. Specifically, refer to... Figure 3 The chip housing the exhaust control unit 131 may have an input pin (not shown), a power supply voltage pin VCC, a first control pin SP1, a second control pin SP2, and a ground pin GND. Among these:

[0073] The anemometer 12 can be connected via the input pin, allowing the reception of its output results. The power supply voltage pin VCC can be connected to the power supply voltage output terminal VDD, providing the necessary power. The first control pin SP1 can be connected to the first switching unit 132, outputting a high-level signal when the exhaust air velocity reaches the upper limit threshold of the outlet air velocity. The first control pin SP1 can also be connected to the second switching unit 133, outputting a high-level signal when the exhaust air velocity reaches the lower limit threshold of the exhaust air velocity.

[0074] In a specific implementation, the first switching unit 132 can be implemented using a second relay. Specifically, refer to... Figure 3 The second relay includes: a second coil T2, a second diode D2, and a second switch K2; the second coil T2 and the second diode D2 are connected in parallel; one end of the second coil T2 is connected to the exhaust control unit 131, and the other end is connected to the second switch K2; the other end of the second switch K2 is connected to the second trigger unit 134.

[0075] The second diode D2 is connected in reverse parallel across the second coil T2 to absorb reverse high voltage and protect the circuit. When energized, the second coil T2 generates a magnetic field that controls the operation of the second switch K2. If the second switch K2 is normally open, the magnetic field generated by the energized coil T2 will close it. If the second switch K2 is normally closed, the magnetic field will open it. When the second coil T2 is de-energized, the magnetic field disappears, and the second switch K2 resets.

[0076] In specific implementation, refer to Figure 3 One end of the second coil T2 can be connected to the first control pin SP1 of the exhaust control unit 131, and the other end can be connected to the power supply voltage pin VCC of the exhaust control unit 131, and is powered by the power supply voltage output terminal VDD. When the first control pin SP1 outputs a high-level signal, it will energize the second coil T2, thereby controlling the operation of the second switch K2.

[0077] In one embodiment, the second switch K2 can be a normally closed switch, so when the second coil T2 is energized, the second switch K2 will open. When the second coil T2 is de-energized, the second switch K2 will close again.

[0078] In a specific implementation, the second switching unit 133 can be implemented using a third relay. Specifically, the third relay includes: a third coil T3, a third diode D3, and a third switch K3; the third coil T3 and the third diode D3 are connected in parallel; one end of the third coil T3 is connected to the exhaust control unit 131, and the other end is connected to the third switch K3; the other end of the third switch K3 is connected to the second triggering unit 134.

[0079] The third diode D3 is connected in reverse parallel across the third coil T3 to absorb reverse high voltage and protect the circuit. When energized, the third coil T3 generates a magnetic field that controls the operation of the third switch K3. If the third switch K3 is normally open, the magnetic field generated by the energized coil T3 will close it. If the third switch K3 is normally closed, the magnetic field generated by the energized coil T3 will open it. When the third coil T3 is de-energized, the magnetic field disappears, and the third switch K3 resets.

[0080] In specific implementation, refer to Figure 3One end of the third coil T3 can be connected to the second control pin SP2 of the exhaust control unit 131, and the other end can be connected to the power supply voltage pin VCC of the exhaust control unit 131, and is powered by the power supply voltage output terminal VDD. When the second control pin SP2 outputs a high-level signal, it will energize the third coil T3, thereby controlling the third switch K3 to operate.

[0081] In one embodiment, the third switch K3 can be a normally closed switch, so when the third coil T3 is energized, the third switch K3 will open. When the third coil T3 is de-energized, the third switch K3 will close again.

[0082] In a specific implementation, the second triggering unit 134 is implemented using a fourth relay; the fourth relay includes: a fourth coil T4, a fourth diode D4, and a fourth switch K4; the fourth diode D4 is connected in parallel with the fourth coil T4; one end of the fourth coil T4 is connected to the first alarm unit 14.

[0083] Specifically, the fourth diode D4 is connected in reverse parallel across the fourth coil T4 to absorb reverse high voltage and protect the circuit. When energized, the fourth coil T4 generates a magnetic field, which controls the operation of the fourth switch K4. If the fourth switch K4 is a normally open switch, the magnetic field generated by the energized coil T4 will close it. If the fourth switch K4 is a normally closed switch, the magnetic field will open it. When the fourth coil T4 is de-energized, the magnetic field disappears, and the fourth switch K4 resets.

[0084] In one embodiment of the present invention, reference is made to... Figure 3 The first switch K1, the second switch K2, and the third switch K3 can be connected in series and connected to one end of the fourth coil T4, while the other end of the fourth coil T4 is grounded. One end of the fourth switch K4 is connected to the power supply voltage output terminal VDD, and the other end is grounded.

[0085] In a specific implementation, the fourth switch K4 can be a normally open switch, which closes when the fourth coil T4 is energized and opens when the fourth coil T4 is de-energized.

[0086] In one embodiment of the present invention, to improve the accuracy of the alarm, the fourth relay may further include a timer. This timer can time the duration of energization of the fourth coil T4, that is, the duration of the low wind speed in the fan filter unit 11. The fourth coil T4 can only control the fourth switch K4 to activate when the low wind speed in the fan filter unit 11 has reached a preset duration, thereby reducing alarms for situations where the power has tripped or stopped and then automatically recovered, thus reducing the false alarm rate.

[0087] In a specific implementation, the first alarm unit 14 may include an alarm switch 141 and an alarm device 142. The alarm switch 141 can control the alarm device 142 to sound when the fourth switch K4 is open, i.e., when there is no signal input. When the fourth switch K4 is closed, it controls the alarm device 142 to not sound.

[0088] In other embodiments, the alarm switch 141 may be omitted, and the alarm 142 may be directly connected to the fourth switch K4, thereby enabling an alarm to be triggered directly based on whether the fourth switch K4 is closed.

[0089] In specific implementation, the first alarm unit 14 can use a variety of methods to trigger an alarm. For example, the alarm 142 can be a buzzer, which can trigger an alarm by emitting a buzzing sound.

[0090] In one embodiment of the present invention, reference is made to... Figure 3 The fan filter unit fault detection circuit further includes a second alarm unit 16. The second alarm unit 16 can be connected to the fault detection unit 15 and is used to issue an alarm when the fan filter unit 11 malfunctions.

[0091] Specifically, the second alarm unit 16 can be connected to the differential output pins S1+ and S1- of the first lower limit comparison result of the fault detection unit 15, thereby enabling direct alarm based on the output of the differential output pins S1+ and S1- of the first lower limit comparison result.

[0092] In some embodiments, the fault detection unit 15 may also be provided with first upper limit comparison result differential output pins S2+ and S2-. The fault detection unit 15 can compare the detection result of the anemometer 12 with the exhaust air velocity upper limit threshold to determine whether the air velocity of the fan filter unit 11 is too high, causing the fan filter unit 11 to be prone to failure. The comparison result of the anemometer 12 detection result and the exhaust air velocity upper limit threshold can be output through the first upper limit comparison result differential output pins S2+ and S2-, and an alarm can be triggered by the second alarm unit 16. The exhaust air velocity upper limit threshold is greater than the outlet air velocity upper limit threshold.

[0093] In practice, the second alarm unit 16 can use various methods to trigger an alarm, such as outputting text alarm information or voice alarm information.

[0094] by Figure 3Taking the circuit structure shown as an example, when the current exhaust wind speed is lower than the lower limit threshold of the exhaust wind speed, the exhaust control unit 131 will output a high-level control signal through the second control pin SP2, which will energize the third coil T3, disconnect the third switch K3, de-energize the fourth coil T4, disconnect the fourth switch K4, and the alarm switch 141 will control the first alarm 142 to sound the alarm because there is no input signal.

[0095] When the current exhaust air velocity is higher than the upper limit threshold of the exhaust air velocity, the exhaust control unit 131 will output a high-level control signal through the first control pin SP1, which will energize the second coil T2, open the second switch K2, de-energize the fourth coil T4, open the fourth switch K4, and the alarm switch 141 will control the first alarm 142 to sound the alarm because there is no input signal.

[0096] Assuming that the second switch K2 and the third switch K3 are both closed, when the current airflow speed of the fan filter unit 11 reaches the lower limit threshold of the airflow speed, the first coil T1 is energized, the first switch K1 is opened, the fourth coil T4 is de-energized, the fourth switch K4 is opened, and the alarm switch 141 controls the first alarm 142 to sound an alarm because there is no input signal.

[0097] Assuming that the second switch K2 and the third switch K3 are both closed, when the current airflow speed of the fan filter unit 11 reaches the upper limit threshold of the airflow speed, the first coil T1 is energized, the first switch K1 is opened, the fourth coil T4 is de-energized, the fourth switch K4 is opened, and the alarm switch 141 controls the first alarm 142 to sound an alarm because there is no input signal.

[0098] The fault detection circuit for the fan filter unit in this embodiment of the invention can not only promptly issue an alarm when the exhaust air velocity reaches the corresponding threshold, but also promptly issue an alarm when the fan filter unit trips or stops operating, reducing the impact on wafer quality and the machine. Furthermore, this fault detection circuit for the fan filter unit is connected to the existing anemometer and exhaust control circuit inside the wafer cleaning machine, utilizing existing components to implement fan alarms. This reduces the cost of fan alarms and minimizes modifications to the cleaning machine structure, achieving maximum compatibility with existing cleaning machine structures.

[0099] While the present invention has been disclosed above, it is not limited thereto. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. A fan filter unit fault detection circuit, comprising: The application is applied to a cleaning machine, which comprises an anemograph, a fan filter unit, an exhaust control circuit and a first alarm unit; the fan filter unit is used to generate wind; the anemograph is used to detect the exhaust wind speed of the fan filter unit; the exhaust control circuit is used to control whether the first alarm unit alarms according to the exhaust wind speed of the fan filter unit; The fan filter unit fault detection circuit is connected with the anemograph and the exhaust control circuit, is used to acquire the detection result of the anemograph, and determines whether the fan filter unit is faulty based on the detection result; and when the fan filter unit is faulty, triggers the first alarm unit to alarm through the exhaust control circuit.

2. The fan filter unit fault detection circuit of claim 1, wherein, The fan filter unit fault detection circuit comprises: A fault detection unit is used to acquire the detection result of the anemograph, and determine whether the fan filter unit is faulty based on the detection result; And a first trigger unit is connected with the fault detection unit and the exhaust control circuit, and is used to trigger the first alarm unit to alarm through the exhaust control circuit when the fan filter unit is faulty.

3. The fan filter unit fault detection circuit of claim 2, wherein, The fault detection unit comprises: A first data receiving subunit is connected with the anemograph, and is used to receive the detection result of the anemograph; And a comparison subunit is connected with the first data receiving subunit, and is used to compare the detection result of the anemograph with the lower threshold of the exhaust wind speed to determine whether the fan filter unit is faulty.

4. The fan filter unit fault detection circuit of claim 2, wherein, The first trigger unit comprises a first relay; the first relay comprises a first coil, a first diode and a first switch; the first coil is connected with the first diode in parallel; one end of the first coil is connected with the fault detection unit; the first switch is connected with the exhaust control circuit.

5. The fan filter unit fault detection circuit of claim 4, wherein, The exhaust control circuit comprises an exhaust control unit, a first switch unit, a second switch unit and a second trigger unit; wherein: The exhaust control unit is connected with the first switch unit and the second switch unit, and is used to acquire the exhaust wind speed and control the alarm trigger unit through the first switch unit or the second switch unit; The second trigger unit is connected with the first switch unit and the second switch unit, and is used to control the first alarm unit to alarm when the corresponding condition is met.

6. The fan filter unit fault detection circuit of claim 5, wherein, The exhaust control unit comprises: A second data receiving subunit is used to acquire the exhaust wind speed; A first control subunit is connected with the second data receiving subunit and the first switch unit, and is used to connect the second trigger unit through the first switch unit when the exhaust wind speed reaches the upper threshold of the exhaust wind speed; A second control subunit is connected with the second data receiving subunit and the second switch unit, and is used to connect the second trigger unit through the second switch unit when the detection result of the anemograph reaches the lower threshold of the exhaust wind speed.

7. The fan filter unit fault detection circuit of claim 5, wherein, The first switch unit is implemented by a second relay; the second relay comprises a second coil, a second diode and a second switch; the second coil is connected with the second diode in parallel; one end of the second coil is connected with the exhaust control unit, and the other end is connected with the second switch; the other end of the second switch is connected with the second trigger unit.

8. The fan filter unit fault detection circuit of claim 5, wherein, The second switch unit is implemented by a third relay; the third relay comprises a third coil, a third diode and a third switch; the third coil is connected with the third diode in parallel; one end of the third coil is connected with the exhaust control unit, and the other end is connected with the third switch; the other end of the third switch is connected with the second trigger unit.

9. The fan filter unit fault detection circuit of claim 5, wherein, The second trigger unit is implemented by a fourth relay; the fourth relay comprises a fourth coil, a fourth diode and a fourth switch; the fourth diode is connected with the fourth coil in parallel; one end of the fourth coil is connected with the first alarm unit.

10. The fan filter unit fault detection circuit of claim 9, wherein, The fourth relay further comprises a timer, which is used for timing the duration of the low wind speed of the fan filter unit; the fourth coil is used for controlling the fourth switch to act when the duration of the low wind speed of the fan filter unit reaches a preset duration.

11. The fan filter unit fault detection circuit of claim 2, wherein, The fan filter unit fault detection circuit further comprises a second alarm unit connected with the fault detection unit, which is used for alarming when the fan filter unit is faulty.

12. A wafer cleaning machine characterized by comprising: The fan filter unit fault detection circuit comprises: The fan filter unit fault detection circuit according to any one of claims 1 to 11.

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