A leak detection method for FFU device after clean room is built

Abstract

The present invention discloses a leak detection method for an FFU device after a clean room is built, wherein the FFU device is located on the ceiling of the clean room; the method comprises the following steps: (1) using at least one set of detection equipment, in conjunction with a positioning system and a data transmission system, to perform a leak detection test on a high-efficiency filter in the FFU device; collecting the detection data; and (2) analyzing and judging the detection data obtained in the above step (1). The present invention realizes an automated leak detection test operation through detection equipment, in conjunction with a positioning system and a data transmission system, and solves the problems of low efficiency and low precision of manual detection in the prior art.

Description

Technical Field

[0001] The invention relates to the field of semiconductor technology, and in particular to a leak detection method for an FFU device after a clean room is built. Background Art

[0002] In the prior art, the semiconductor integrated circuit (IC) industry has experienced exponential growth, and technological advances in IC materials and design have produced multiple generations of ICs, each with smaller and more complex circuits than the previous generation. During the development of ICs, functional density has increased significantly while geometric dimensions have decreased. Generally, this scaling down process provides many benefits by improving production efficiency and reducing related costs. This scaling down increases the complexity of processing and producing ICs, and also places increasingly higher requirements on the production environment (clean room).

[0003] A clean room is a well-sealed space that controls air cleanliness, temperature, humidity, pressure, noise and other parameters as required. According to statistics in China, the qualified rate of MOS circuit dies produced in an environment without clean level requirements is only 10% to 15%, and the qualified rate of 64-bit storage is only 2%. Therefore, the application of clean rooms in industries such as precision machinery, semiconductors, aerospace, and atomic energy is already a basic equipment.

[0004] The clean room in the prior art includes a clean space, a ceiling and a raised floor. The ceiling is provided with a plurality of air supply areas, each of which includes at least one air supply mechanism, which is usually an FFU device. The function of the FFU device is to supply air and filter larger particulate pollutants. In the actual construction process, after the construction of the traditional clean room is completed, the FFU device on the ceiling must be tested for high-efficiency filter leakage (HEPA filter leakage test) to ensure that all FFU devices are intact and prevent leakage caused by damage to the high-efficiency filter.

[0005] In response to the above-mentioned HEPA filter leakage test requirements, the existing practice is to perform the test manually, that is, to use a particle counter and a probe to scan the entire surface of the HEPA.

[0006] However, this method has the following problems: (1) As the area of ​​existing clean rooms is generally large, the number of high-efficiency filters installed in the clean rooms is in the tens of thousands, so the speed of manual inspection cannot keep up and the efficiency is too low; (2) As the height of existing clean rooms is getting higher and higher, the general height is about 4 to 6 meters, and there are also many clean rooms above 10 meters. Therefore, workers need to rely on elevators when conducting inspections. On the one hand, there are safety hazards, and on the other hand, the elevators also affect the inspection work, resulting in reduced test accuracy; (3) When workers use probes for inspection, the probe moves too fast, or the scanning path does not overlap partially, which may result in missing leakage points, that is, missing detection, which has a fatal impact on the inspection results; (4) Manual inspection will be affected by human subjectivity, and the test results will also be affected by human subjectivity.

[0007] Therefore, it is obviously of positive practical significance to develop a leak detection method for the FFU device located on the ceiling after the clean room is built to quickly and accurately complete the leak detection test of the high-efficiency filter. Summary of the invention

[0008] The object of the present invention is to provide a leak detection method for an FFU device after a clean room is built.

[0009] To achieve the above object, the technical solution adopted by the present invention is: a leak detection method for an FFU device after the clean room is built, wherein the FFU device is located on the ceiling of the clean room; comprising the following steps:

[0010] (1) using at least one set of detection equipment, in conjunction with a positioning system and a data transmission system, to perform a leak test on the high efficiency filter in the FFU device; and collecting the detection data;

[0011] Each group of the detection equipment includes an upper carrier, a detection light source, a lower carrier and a receiver; the upper carrier is used to carry the detection light source and has three-dimensional freedom of movement of x, y and z; the detection light source is annular and has at least one group of colored lamp beads, and each group of colored lamp beads is composed of red lamp beads, orange lamp beads, yellow lamp beads, green lamp beads, blue lamp beads, cyan lamp beads and purple lamp beads in sequence; the light emitted by the detection light source is in a truncated cone shape; the lower carrier is used to carry the receiver and has three-dimensional freedom of movement of x, y and z; the detection light source and the receiver of each group of the detection equipment are arranged one by one up and down, and the receiver is used to receive the light signal of the detection light source; during detection, the detection light source is in a rotating state;

[0012] (2) Analyze the detection data obtained in step (1) above. If there are light spots of different colors at a certain location, it is necessary to make a judgment:

[0013] (a) If the color of the leaking light spot contains a light spot color with a long wavelength, it is determined that there is a leak at that location;

[0014] (b) If the light spots of the leak are all short-wavelength light spots, a single-color long-wavelength light source is used to retest according to the method of step (1). If the long-wavelength light source appears, it is determined that there is a leak. Otherwise, manual re-inspection is performed;

[0015] The colors of the short-wavelength light spots are blue, cyan, and purple; the colors of the long-wavelength light spots are red, orange, yellow, and green.

[0016] In the above, in (a) and (b) of step (2), the leaked light spot color is synthetic light in most cases. This is because when there is a long-wavelength light spot color, short-wavelength light will also leak out. Therefore, when detecting the leaked light spot color, the leaked light needs to be decomposed. When the decomposed light contains long-wavelength light spot colors (such as red, orange, yellow, and green), it is determined to be a leak. If the decomposed light contains only short-wavelength light spot colors (such as blue, cyan, and purple), retesting is required.

[0017] In the above, the detection equipment can be a group or multiple groups at the same time. The detection operation can be uniformly controlled by a control system. The positioning system is used to locate the detection equipment, so as to control it to move and detect according to the set route. The data transmission system is used to transmit the detection data to a designated system or device so as to conduct further research and judgment on these data.

[0018] The upper carrier and the lower carrier are arranged in a matching manner, the upper carrier is used to carry the detection light source, and the lower carrier is used to carry the receiver. At the same time, the detection light source and the receiver are also arranged in a matching manner, the detection light source is used to emit light, and the receiver is used to receive light signals.

[0019] The detection light source is annular, and has at least one group of colored lamp beads, each group of colored lamp beads is composed of red lamp beads, orange lamp beads, yellow lamp beads, green lamp beads, blue lamp beads, cyan lamp beads, and purple lamp beads in sequence, and a group of colored lamp beads is in a rotating state during detection, and in the rotating state, these colored lamp beads can be mixed to form white light. The light emitted by the detection light source is in a truncated cone shape, that is, the lamp beads are arranged obliquely downward, and the angle between them and the longitudinal axis is the inclination angle θ.

[0020] The present invention innovatively adopts seven colors of light for detection, and regards the leakage holes on the high-efficiency filter as sieve holes. When the sieve holes are small, long wavelengths cannot pass through, and only short wavelengths can pass through; therefore, if the color of the leaking light spot contains a long-wavelength light spot color (or simply synthetic white light), it means that the hole is already larger, and it is necessary to determine that there is a leak at that location, and manual review must be carried out (basically there is a leak); on the contrary, if the color of the leaking light spot is all short-wavelength light spot color, the hole may be very small, or it may be a gap between the filter material fibers, so manual review and manual confirmation are required.

[0021] Preferably, in step (1), the detection equipment includes at least two groups, one group is used for leak testing of the high-efficiency filter; and the other group is used for leak testing between the high-efficiency filter and the ceiling keel;

[0022] The other set of detection equipment for leak detection test between the high-efficiency filter and the ceiling keel includes a second upper carrier, a second detection light source, a second lower carrier and a second receiver; the second detection light source is rectangular and is composed of a plurality of LED point light sources.

[0023] The second detection light source is rectangular, which can be a rectangle or a square, as long as it matches the HEPA.

[0024] Preferably, in step (1), the upper vehicle is a drone, and the lower vehicle is a drone.

[0025] Preferably, in step (1), the receiver is a CMOS Image Sensor.

[0026] Preferably, in step (1), the positioning system is based on a BIM software system and is used to detect the addressing and positioning of the upper and lower vehicles of the equipment. The BIM software system is a prior art. BIM provides a three-dimensional map for navigation. The present invention is based on a three-dimensional building model and provides a positioning system as a reference mark for the movement of the upper and lower vehicles and the addressing of measurement data.

[0027] Preferably, in step (1), the distance H between the FFU device and the detection light source needs to be calibrated first to avoid the shielding effect caused by the fan and its blades in the FFU device, as follows:

[0028] The detection light source is in a circular shape, with a diameter of d, and the inclination angle of the colored lamp beads thereon is θ; the diameter of the bell mouth entrance of the FFU device is D, and the distance between the top of the fan blade of the FFU device and the edge of the bell mouth is h; then: H = (Dd) / 2tanθ-h.

[0029] Since there are many models of FFU devices and their specifications vary greatly, in addition to the calibration method described above, manual calibration is preferred: first, set the upper carrier above the FFU fan without installing HEPA, irradiate with a detection light source, and set a receiver under the FFU fan to determine the distance between the upper carrier and the FFU (this step can be done outside the clean room or in the FFU factory).

[0030] Preferably, in step (1), the detection equipment detects the FFU devices on the ceiling in sequence according to the positioning system.

[0031] Preferably, in step (1), during detection, the detection light source is in a rotating state; its rotation speed is 100 to 600 revolutions / min, preferably 150 to 500 revolutions / min, more preferably 250 to 400 revolutions / min, and more preferably 300 to 350 revolutions / min.

[0032] Preferably, before step (1), the clean room is fully cleaned; then the FFU device is turned on to detect whether it is operating normally: if the FFU device is operating normally, proceed to step (1); otherwise, the FFU device needs to be repaired or replaced.

[0033] Preferably, step (1) is performed at night, and more preferably, in a dark and unmanned environment.

[0034] The mechanism of the present invention is as follows: the detection light source is annular and is directed toward the FFU suction port at an inclined angle (truncated cone shape), and irradiates the blades of the impeller, flashes through the motor head of the impeller, forms a reflection and enters the air box chamber of the FFU, and then the air box chamber forms a reflection to form a light field; different color light sources are used to mix light, so as to use different light wavelengths to screen the filter holes.

[0035] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art:

[0036] 1. The present invention develops a new leak detection method for FFU devices after the clean room is built. The automatic leak detection test operation is realized through the detection equipment, the positioning system and the data transmission system, which solves the problems of low efficiency and low precision of manual detection in the prior art; it solves the technical problems that have long been urgently needed to be solved in the industry but have never been solved, and has significant progress and positive practical significance;

[0037] 2. Since the present invention adopts the light source detection method, but the fan and its blades in the FFU device will shield the high-efficiency filter located below, therefore, in view of this new technical problem, the present invention designs the detection light source to be annular, and is composed of red lamp beads, orange lamp beads, yellow lamp beads, green lamp beads, blue lamp beads, cyan lamp beads, and purple lamp beads in sequence, and makes the detection light source in a rotating state during detection, so that when the light is irradiated to the hole on the high-efficiency filter, the light is diffracted, so that light spots of different colors are obtained in the receiver sent down; thereby perfectly solving the above new technical problems and improving the detection accuracy;

[0038] 3. When judging whether there is a leak, the present invention can first detect the wavelength of the color of the leaking light spot. When the color of the leaking light spot is a short wavelength, a single color long wavelength light source can be used for retesting, thereby more accurately determining the leak point, reducing the possibility of misjudgment, and greatly reducing the workload;

[0039] 4. Previously, in the actual operation process, even if the leak test of the high-efficiency filter was completed manually, there was still a leakage problem in the actual production process. For this special problem, the inventor found through years of work experience that: in addition to the leak test of the high-efficiency filter itself, there is another overlooked leakage point: that is, the gap between the high-efficiency filter and the keel on which it is assembled; and for this new technical problem, if the previous manual inspection is adopted, even if the gap is inspected, it is difficult to carry out: because once the gap is found, it needs to be reinstalled later, and when it is manually inspected again after installation, it is often a matter of a few days later, which leads to the inability to connect the front and the back; and the present invention adopts another set of detection equipment, through the rectangular detection light source, and the upper and lower height adjustment of the upper vehicle (drone), it can quickly detect on the spot, even if the FFU is reinstalled, it can also quickly perform a second inspection, so that the detection operation can be completed efficiently;

[0040] 5. The detection method of the present invention is simple and easy to implement, will not be affected by human subjective influence, and has a high accuracy rate; in addition, it can be operated at night without affecting the normal operation of personnel, has low cost and high efficiency, and is therefore suitable for promotion and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 is a schematic diagram of the structure of the first group of detection equipment in Embodiment 1 of the present invention;

[0042] Figure 2 is a schematic diagram of the structure of the detection light source in the first embodiment of the present invention;

[0043] Figure 3 It is a partial connection diagram of the high efficiency filter and the ceiling keel in the first embodiment of the present invention;

[0044] Figure 4 is a schematic structural diagram of the second detection light source in the first embodiment of the present invention;

[0045] Figure 5 is a three-dimensional diagram of the FFU device in the first embodiment of the present invention;

[0046] Figure 6 yes Figure 5 A partial front view of

[0047] Figure 7 yes Figure 6 The structural diagram of the fan;

[0048] Figure 8 yes Figure 6 Schematic diagram of the distance relationship between the fan and the detection light source.

[0049] Among them: 1. Upper carrier; 2. Detection light source; 3. Lower carrier; 4. Receiver; 5. High efficiency filter; 6. Ceiling keel; 7. LED point light source; 8. Fan; 21. Colored lamp beads. DETAILED DESCRIPTION

[0050] The present invention will be further described with reference to the accompanying drawings and embodiments:

[0051] Embodiment 1

[0052] See also Figures 1 to 7 As shown, a leak detection method for an FFU device after a clean room is built, wherein the FFU device is located on the ceiling of the clean room; the method comprises the following steps:

[0053] (1) First, perform full-area cleaning of the clean room; then, turn on the FFU device to check whether it is operating normally: if the FFU device is operating normally, proceed to the next step; otherwise, the FFU device needs to be repaired or replaced;

[0054] (2) using two sets of detection equipment, in conjunction with a positioning system and a data transmission system, to perform a leak test on the high-efficiency filter in the FFU device; and collecting the detection data;

[0055] See also Figure 1 The first set of detection equipment is used for leak detection of high efficiency filter 5; it includes an upper carrier 1, a detection light source 2, a lower carrier 3 and a receiver 4; the upper carrier is used to carry the detection light source and has x, y, z three-dimensional freedom of movement (the upper carrier is located above the fan 8 of FFU); the detection light source is annular, see Figure 2, it has 2 groups of colored lamp beads 21, each group of colored lamp beads is composed of red lamp beads, orange lamp beads, yellow lamp beads, green lamp beads, blue lamp beads, cyan lamp beads, and purple lamp beads in sequence; the light emitted by the detection light source is in a truncated cone shape; the carrier is used to carry the receiver and has x, y, z three-dimensional freedom of movement; the detection light source and the receiver of each group of the detection equipment are arranged one by one, and the receiver is used to receive the light signal of the detection light source; during detection, the detection light source is in a rotating state;

[0056] See also Figure 3 The second set of detection equipment is used for leak detection between the high efficiency filter 5 and the ceiling keel 6, which includes a second upper carrier, a second detection light source, a second lower carrier and a second receiver (similar to the first set of detection equipment, no additional drawings are provided); the second detection light source is rectangular, see Figure 4 , which is composed of a plurality of LED point light sources 7;

[0057] The testing operations of the first and second groups of testing equipment can be carried out separately, in no particular order;

[0058] (3) Analyze the detection data obtained in step (2) above. If there are light spots of different colors at a certain location, it is necessary to make a judgment:

[0059] (a) If the color of the leaking light spot contains a light spot color with a long wavelength, it is determined that there is a leak at that location;

[0060] (b) If the colors of the light spots of the leakage are all short-wavelength light spots, a single-color long-wavelength light source is used to retest according to the method of the above step (2). If the long-wavelength light source appears, it is determined that there is a leakage. Otherwise, manual re-inspection is performed;

[0061] The colors of the short-wavelength light spots are blue, cyan, and purple; the colors of the long-wavelength light spots are red, orange, yellow, and green.

[0062] The detection operation can be uniformly controlled by a control system. The positioning system is used to locate the detection equipment, so as to control it to move and detect according to the set route. The data transmission system is used to transmit the detection data to a designated system or device so as to conduct further research and judgment on these data.

[0063] The upper carrier and the lower carrier are arranged in a matching manner, the upper carrier is used to carry the detection light source, and the lower carrier is used to carry the receiver. At the same time, the detection light source and the receiver are also arranged in a matching manner, the detection light source is used to emit light, and the receiver is used to receive light signals.

[0064] The detection light source is in the shape of a ring, and has two groups of colored lamp beads. It is in a rotating state during detection (its rotation speed is 400-450 revolutions / min). In the rotating state, these colored lamp beads can be mixed to become white light. The light emitted by the detection light source is in the shape of a truncated cone, that is, the lamp beads are arranged obliquely downward, and the angle between them and the longitudinal axis is the inclination angle θ; see Figure 8 .

[0065] The present invention innovatively adopts seven colors of light for detection, and regards the leakage holes on the high-efficiency filter as sieve holes. When the sieve holes are small, long wavelengths cannot pass through, and only short wavelengths can pass through; therefore, if the color of the leaking light spot contains a long-wavelength light spot color (or simply synthetic white light), it means that the hole is already larger, and it is necessary to determine that there is a leak at that location, and manual review must be carried out (basically there is a leak); on the contrary, if the color of the leaking light spot is all short-wavelength light spot color, the hole may be very small, or it may be a gap between the filter material fibers, so manual review and manual confirmation are required.

[0066] In this embodiment, the upper vehicle and the lower vehicle are both drones, and the second upper vehicle and the second lower vehicle are both drones. The receiver is a CMOS Image Sensor.

[0067] In this embodiment, the positioning system is based on the BIM software system and is used to detect the addressing and positioning of the upper and lower vehicles of the equipment. The BIM software system is a prior art. BIM provides a three-dimensional map for navigation. The present invention is based on the three-dimensional model of the building and provides a positioning system as a reference mark for the movement of the upper and lower vehicles and the addressing of the measurement data.

[0068] In this embodiment, the distance H between the FFU device and the detection light source needs to be calibrated first to avoid the shielding effect caused by the fan and its blades in the FFU device, as follows:

[0069] See also Figure 2 , 5 ~8, the detection light source is in a circular shape, with a diameter of d, and the inclination angle of the colored lamp beads thereon is θ; the diameter of the bell-mouth entrance of the FFU device is D, and the distance between the top of the fan blade of the FFU device and the edge of the bell-mouth is h; then: H = (Dd) / 2tanθ-h.

[0070] Since there are many models of FFU devices and their specifications vary greatly, in addition to the calibration method described above, this embodiment adopts manual calibration: first, the upper carrier is set above the FFU fan without installing HEPA, and irradiated with a detection light source, and a receiver is set below the FFU fan to determine the distance between the upper carrier and the FFU (this step can be done outside the clean room and can also be done in the FFU factory).

[0071] In this embodiment, the detection device detects the FFU devices on the ceiling in sequence according to the positioning system. The step (2) is performed at night.

[0072] Comparative Example

[0073] The same sequence and steps as those in the embodiment are used, but manual detection is performed entirely using a particle counter and a probe.

[0074] For the same Class 100 clean room, using 1.2m×1.2m FFU (assuming an area of ​​15,000 square meters, about 4,200 FFUs, a height of 7.8 meters, and a scaffold must be used for scanning), the detection time of Example 1 is 70 hours, while that of the comparative example is 4,200 units×8 minutes / unit=560 hours. It can be seen that the efficiency of the present invention has been substantially improved.

[0075] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A leak detection method for a FFU device after a clean room is built, wherein the FFU device is located on the ceiling of the clean room; characterized in that: The steps include: (1) using at least one set of detection equipment, in conjunction with a positioning system and a data transmission system, to perform a leak test on the high efficiency filter in the FFU device; and collecting the detection data; Each group of the detection equipment includes an upper carrier, a detection light source, a lower carrier and a receiver; the upper carrier is used to carry the detection light source and has three-dimensional freedom of movement of x, y and z; the detection light source is annular and has at least one group of colored lamp beads, and each group of colored lamp beads is composed of red lamp beads, orange lamp beads, yellow lamp beads, green lamp beads, blue lamp beads, cyan lamp beads and purple lamp beads in sequence; the light emitted by the detection light source is in a truncated cone shape; the lower carrier is used to carry the receiver and has three-dimensional freedom of movement of x, y and z; the detection light source and the receiver of each group of the detection equipment are arranged one by one up and down, and the receiver is used to receive the light signal of the detection light source; during detection, the detection light source is in a rotating state; (2) Analyze the detection data obtained in step (1) above. If there are light spots of different colors at a certain location, it is necessary to make a judgment: (a) If the color of the leaking light spot contains a light spot color with a long wavelength, it is determined that there is a leak at that location; (b) If the light spots of the leak are all short-wavelength light spots, a single-color long-wavelength light source is used to retest according to the method of step (1). If the long-wavelength light source appears, it is determined that there is a leak. Otherwise, manual re-inspection is performed; The colors of the short-wavelength light spots are blue, cyan, and purple; the colors of the long-wavelength light spots are red, orange, yellow, and green.

2. The leak detection method according to claim 1, characterized in that: In the step (1), the detection equipment includes at least two groups, one group is used for leak testing of the high-efficiency filter; and the other group is used for leak testing between the high-efficiency filter and the ceiling keel; The other set of detection equipment for leak detection test between the high-efficiency filter and the ceiling keel includes a second upper carrier, a second detection light source, a second lower carrier and a second receiver; the second detection light source is rectangular and is composed of a plurality of LED point light sources.

3. The leak detection method according to claim 1, characterized in that: In the step (1), the upper vehicle is a drone, and the lower vehicle is a drone.

4. The leak detection method according to claim 1, characterized in that: In the step (1), the receiver is a CMOS Image Sensor.

5. The leak detection method according to claim 1, characterized in that: In the step (1), the positioning system is based on a BIM software system and is used to detect the addressing and positioning of the upper and lower carriers of the equipment.

6. The leak detection method according to claim 1, characterized in that: In step (1), the distance H between the FFU device and the detection light source needs to be calibrated first to avoid the shielding effect caused by the fan and its blades in the FFU device, as follows: The detection light source is in a circular shape, with a diameter of d, and the inclination angle of the colored lamp beads thereon is θ; the diameter of the bell mouth entrance of the FFU device is D, and the distance between the top of the fan blade of the FFU device and the edge of the bell mouth is h; then: H = (Dd) / 2tanθ-h.

7. The leak detection method according to claim 1, characterized in that: In the step (1), the detection equipment detects the FFU devices on the ceiling in sequence according to the positioning system.

8. The leak detection method according to claim 1, characterized in that: In the step (1), during detection, the detection light source is in a rotating state; The rotation speed is 100 to 600 revolutions / min.

9. The leak detection method according to claim 1, characterized in that: Before step (1), the clean room is fully cleaned; then the FFU device is turned on to detect whether it is operating normally: if the FFU device is operating normally, proceed to step (1); otherwise, the FFU device needs to be repaired or replaced.

10. The leak detection method according to claim 1, characterized in that: The step (1) is performed at night.

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