Grinding fluid titration device and liquid level detection method

Abstract

The invention discloses a grinding fluid titration device, which comprises: a first container for accommodating a grinding fluid; the at least two monitoring devices are arranged in the first container and / or on the side wall of the first container and used for monitoring the liquid level of the grinding liquid in the first container; the mounting height of the monitoring device is correspondingly set according to at least two liquid level preset heights of the grinding liquid, so that when the liquid level of the grinding liquid in the first container is at the mounting height, the corresponding monitoring device is triggered; the light blocking device floats on the surface of the grinding liquid; wherein at least one monitoring device monitors the liquid level of the grinding liquid based on the light blocking device; when one of the monitoring devices goes wrong, other monitoring devices work normally, so that the working accuracy and stability of the grinding fluid titration device are ensured.

Description

Technical Field

[0001] The present invention relates to the field of wafer grinding, and particularly to a grinding fluid titration device and a liquid level detection method. Background Art

[0002] Since the second half of the 20th century, electronic technology has developed rapidly, and many products supported by traditional technologies have gradually been supported by electronic technologies. With the development of semiconductor technology, the size of electronic devices has gradually shrunk, and the surface flatness of wafers is required to reach the nanometer level. High-integration electronic components require three-dimensional wiring or multi-layer wiring to connect transistors. Unevenness between layers will cause them not to be superimposed, so global planarization must be carried out. There are many common traditional planarization technologies, which can only achieve local planarization and cannot meet the process requirements of global planarization. Subsequently, the chemical mechanical polishing (CMP) technology emerged.

[0003] CMP is one of the key technologies for the surface processing of semiconductor substrates. It can make the substrate surface more flat, and also has the advantages of low processing cost and simple processing method. Therefore, it has become the most common semiconductor material surface planarization technology at present.

[0004] The grinding fluid plays a crucial role in CMP. The grinding fluid is a mixture composed of grinding particles and chemical agents. During the substrate polishing process, the grinding fluid is provided to the substrate through a grinding fluid delivery system. The chemical substances in the grinding fluid react with the layer to be ground on the substrate to form a compound that can be removed by abrasive particles, and then the abrasive provides mechanical grinding force to remove the compound, thereby completing the grinding and polishing.

[0005] The grinding fluid delivery system includes a grinding fluid titration device for providing the grinding fluid for titration ratio. The current grinding fluid titration device adopts a single-determination forward liquid-taking method. There is a liquid level sensor on the grinding fluid titration device. The liquid level sensor can be set inside the titration device. However, after long-term and multiple uses, the liquid level sensor may be corroded by the grinding fluid, thus affecting its monitoring and alarm functions. There is also a liquid level sensor set outside the titration device. However, this setting is prone to looseness when replacing the titration device, resulting in false alarm phenomena.

[0006] The stability and correctness of the grinding fluid liquid level monitoring directly affect the time of the grinding fluid titration ratio. If the liquid level monitoring is unstable or incorrect, it will lead to false alarms in the volume measurement of the detected grinding fluid. Furthermore, the machine determines that the grinding fluid in the grinding fluid titration device is empty and stops titration, halting the titration ratio, thereby affecting the supply of the grinding fluid to the substrate at the machine end and increasing the instability of the machine process. Summary of the Invention

[0007] The object of the present invention is to solve the problem that the liquid level monitoring of the current abrasive titration device is unstable, resulting in false alarms in the volume measurement of the abrasive liquid.

[0008] To achieve the above object, a first aspect of the present invention provides an abrasive titration device, including: a first container for containing the abrasive liquid; at least two monitoring devices arranged inside and / or on the side wall of the first container for monitoring the liquid level of the abrasive liquid in the first container; the installation height of the monitoring devices is set corresponding to at least two preset liquid level heights of the abrasive liquid, so that when the liquid level of the abrasive liquid in the first container is at the installation height, the corresponding monitoring device is triggered; a light-blocking device floating on the surface of the abrasive liquid; wherein, at least one of the monitoring devices monitors the liquid level of the abrasive liquid based on the light-blocking device.

[0009] Optionally, when there are at least three monitoring devices, two of the monitoring devices correspond to the same preset liquid level height and are arranged at the same height.

[0010] Optionally, the monitoring device at least includes any one or more of a pressure sensor, a liquid level sensor or an optical sensor; if the monitoring device is a pressure sensor, when the light-blocking device reaches the height of the pressure sensor, the pressure sensor is triggered; if the monitoring device is a liquid level sensor, when the liquid level of the abrasive liquid reaches the height of the liquid level sensor, the liquid level sensor is triggered; if the monitoring device is an optical sensor, when the light-blocking device reaches the height of the optical sensor, the optical sensor is triggered.

[0011] Optionally, a liquid inlet is provided at the top of the first container for adding the abrasive liquid into the first container; a liquid supply port is provided at the bottom of the first container for supplying the abrasive liquid to the outside.

[0012] Optionally, the side wall of the first container includes an inner side wall and an outer side wall.

[0013] Optionally, a drainage component is vertically arranged inside the first container for guiding the abrasive liquid to flow into the first container, the first end of the drainage component is located at the liquid inlet, and the second end of the drainage component is fixed at the bottom of the first container.

[0014] Optionally, at least one of the monitoring devices is arranged on the drainage component.

[0015] Optionally, a pressure sensor is arranged as the monitoring device at the second end of the drainage component.

[0016] Optionally, the monitoring device is arranged on the side wall of the first container or on the drainage component.

[0017] Optionally, the abrasive liquid titration device further includes: an isolation cover, which is inverted in the first container, the bottom of the isolation cover communicates with the first container, the drainage component passes through the top of the isolation cover, and the first end of the drainage component is connected to the top of the isolation cover, so that after the abrasive liquid enters from the liquid inlet, it flows through the first end of the drainage component and the outer side wall of the isolation cover in sequence and then flows to the bottom of the first container.

[0018] Optionally, the light-blocking device is disposed in the isolation cover around the drainage component.

[0019] Optionally, a filter layer is provided between the outer wall of the isolation cover and the inner wall of the first container.

[0020] Optionally, the liquid inlet of the first container is funnel-shaped.

[0021] Optionally, the density of the light-blocking device is less than the density of the abrasive liquid and the density of the light-blocking device is uniform.

[0022] In a second aspect of the present invention, a liquid level detection method is proposed, which uses the above-mentioned abrasive liquid titration device, and includes the steps of: setting the installation height of the monitoring device according to at least two preset liquid level heights of the abrasive liquid on the inside and / or side wall of the first container; adding the abrasive liquid into the first container so that the abrasive liquid flows to the bottom of the first container; controlling the abrasive liquid to flow out from the bottom of the first container, and when the abrasive liquid in the first container is reduced to the preset liquid level height, the monitoring device corresponding to the height is triggered; wherein, before the abrasive liquid flows out from the bottom of the first container, the liquid level height of the abrasive liquid in the first container is greater than the maximum preset liquid level height.

[0023] Optionally, when the monitoring devices with the same installation height are not triggered simultaneously, check the monitoring devices that are not triggered.

[0024] Optionally, when the monitoring device corresponding to the smaller preset liquid level height is triggered, while the monitoring devices corresponding to the larger preset liquid level heights are not all triggered, check the monitoring devices corresponding to the larger preset liquid level heights that are not triggered.

[0025] Compared with the prior art, the present invention has at least the following advantages and beneficial effects:

[0026] In this solution, at least two monitoring devices are provided on the inside and / or side wall of the first container to jointly monitor the liquid level of the abrasive liquid in the first container, and the installation height of the monitoring device is correspondingly set according to at least two preset liquid level heights, so that when one of the monitoring devices fails, other monitoring devices can still work normally, thereby ensuring the accuracy and stability of the operation of the abrasive liquid titration device;

[0027] This solution sets at least one monitoring device to monitor the liquid level of the grinding fluid based on the light-blocking device, and uses more than one detection principle to monitor the liquid level, reducing the dependence of the liquid level monitoring device on the liquid level sensor and reducing the possibility of simultaneous errors in the monitoring device;

[0028] This solution sets two monitoring devices in multiple monitoring devices to correspond to the same preset liquid level height, thereby strengthening the monitoring of the grinding fluid liquid level and ensuring the normal progress of the liquid level monitoring work. Description of the Drawings

[0029] Figure 1 It is a schematic structural diagram of the grinding fluid titration device according to an embodiment of the present invention;

[0030] Figure 2 It is a schematic diagram when the grinding fluid liquid level reaches the first preset liquid level height in an embodiment of the present invention;

[0031] Figure 3 It is a schematic diagram when the grinding fluid liquid level reaches the second preset liquid level height in an embodiment of the present invention. Detailed Embodiments

[0032] The following will combine the drawings in the embodiments of the present invention to elaborate in detail on the technical solutions, structural features, achieved objectives, and effects in the embodiments of the present invention.

[0033] It should be noted that the drawings adopt a very simplified form and all use non-precise scales, only for the purpose of conveniently and clearly assisting in explaining the purpose of the embodiments of the present invention, and are not used to limit the limiting conditions for the implementation of the present invention. Therefore, they do not have technical substance significance. Any modification of the structure, change of the proportional relationship, or adjustment of the size, without affecting the effects that the present invention can produce and the objectives that can be achieved, should still fall within the scope covered by the technical content disclosed by the present invention.

[0034] It should be noted that in the present invention, the terms "include", "comprise", or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device including a series of elements not only includes the clearly listed elements, but also includes other elements not clearly listed, or further includes elements inherent to such a process, method, article, or device.

[0035] As described in the background art, the current abrasive liquid titration device has the problem of unstable liquid level monitoring by the liquid level sensor, resulting in false alarms for the volume measurement of the abrasive liquid, thus affecting the titration ratio of the abrasive liquid and indirectly affecting the liquid supply to the machine end. To solve this problem, the present invention proposes an abrasive liquid titration device, which monitors the liquid level of the abrasive liquid by providing at least two liquid level monitoring devices with different heights on the inside and / or side walls of the abrasive liquid titration container, so that when a certain liquid level monitoring device fails, the liquid level of the abrasive liquid in the abrasive liquid titration device can still be stably monitored.

[0036] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings.

[0037] As Figure 1 shown, an abrasive liquid titration device provided in this embodiment includes: a first container 10, and a plurality of monitoring devices provided on the inside and side walls of the first container 10; the first container 10 is used to hold the abrasive liquid and provide the abrasive liquid for subsequent titration ratio, and a liquid inlet 11 is provided at the top of the first container 10, and the liquid inlet 11 is used to add the abrasive liquid into the first container 10, and the liquid inlet 11 is in the shape of a funnel with a larger top and a smaller bottom, so as to facilitate adding liquid into the first container 10 and the funnel-shaped design can also play a role in guiding the flow, avoiding the splashing of the abrasive liquid outward and improving the safety of the operation; a liquid supply port 15 is further provided at the bottom of the first container 10, which is used to provide the abrasive liquid to the outside for titration ratio; the abrasive liquid titration device of this embodiment includes three such monitoring devices, namely a first monitoring device, a second monitoring device and a third monitoring device, the first monitoring device and the second monitoring device are respectively a liquid level sensor 12 and an optical sensor 13, which are provided at the same first installation height, and the third monitoring device is a pressure sensor 14, which is provided at a second installation height, and the second installation height is less than the first installation height, that is, the third monitoring device is closer to the bottom of the first container than the first monitoring device and the second monitoring device.

[0038] The abrasive liquid titration device further includes a guiding component 16, which is vertically arranged in the first container 10 and is used to guide the abrasive liquid to flow into the first container 10 from the liquid inlet 11 at the top of the first container 10. The first end of the guiding component 16 is located at the liquid inlet 11, and the second end of the guiding component 16 is fixed at the bottom of the first container 10. When the abrasive liquid is introduced from the liquid inlet 11 at the top of the first container 10, the abrasive liquid flows along the guiding component 16 into the first container 10 and accumulates at its bottom. The guiding component 16 plays a role in guiding the abrasive liquid and can prevent the abrasive liquid from splashing when flowing into the first container 10.

[0039] The grinding fluid titration device further includes a light-blocking device 17 floating on the surface of the grinding fluid. Both the optical sensor 13 and the pressure sensor 14 in the monitoring device monitor the liquid level of the grinding fluid based on this light-blocking device 17, enabling the grinding fluid titration device of this solution to monitor the liquid level based on more than one detection principle, reducing the dependence on the liquid level sensor and lowering the possibility of the monitoring device malfunctioning simultaneously. The light-blocking device 17 is arranged around the drainage component 16, so that the height of the light-blocking device 17 can change with the change in the height of the surface of the grinding fluid, and the drainage component 16 functions to limit the horizontal position of the light-blocking device 17 to prevent the light-blocking device 17 from undergoing an obvious change in horizontal position and affecting the liquid level monitoring functions of the optical sensor 13 and the pressure sensor 14.

[0040] In other embodiments, the drainage component 16 may not be used, but it is necessary to ensure that the light-blocking device 17 does not move significantly horizontally within the first container 10.

[0041] Furthermore, to ensure that the light-blocking device 17 can float on the surface of the grinding fluid, a material with a density less than that of the grinding fluid is selected to make the light-blocking device 17, and the density of the light-blocking device 17 is controlled to be uniform to keep the light-blocking device 17 as stable as possible on the surface of the grinding fluid.

[0042] The first installation height is set according to the preset height of the first liquid level of the grinding fluid, and the second installation height is set according to the preset height of the second liquid level of the grinding fluid. When the liquid level of the grinding fluid in the first container 10 is at the preset height of the first liquid level, the first monitoring device and the second monitoring device at the first installation height are triggered. When the liquid level of the grinding fluid in the first container 10 is at the preset height of the second liquid level, the third monitoring device at the second installation height is triggered.

[0043] Specifically, the first monitoring device is a liquid level sensor 12, such as Figure 2As shown, when the liquid level of the abrasive liquid in the first container 10 reaches the first installation height of the liquid level sensor 12, the liquid level sensor 12 is triggered. At this time, the liquid level of the abrasive liquid in the first container 10 should be the first preset liquid level height; the second monitoring device is the optical sensor 13. The optical sensor 13 monitors the liquid level of the abrasive liquid in the first container 10 based on the light blocking device 17. When the liquid level of the abrasive liquid is higher than the first installation height of the optical sensor 13, the light blocking device 17 is higher than the optical sensor 13 and does not block the optical path and the reception of the optical signal of the optical sensor 13. When the liquid level of the abrasive liquid reaches the first installation height of the optical sensor 13, the light blocking device 17 is also at the height of the optical sensor 13, blocking the optical path and the reception of the optical signal of the optical sensor 13, so that the optical sensor 13 is triggered. At this time, the liquid level of the abrasive liquid in the first container 10 should also be the first preset liquid level height; the third monitoring device is the pressure sensor 14, which is arranged inside the first container 10. In this embodiment, the pressure sensor 14 is arranged on the drainage component 16, such as Figure 3 As shown, when the liquid level of the abrasive liquid in the first container 10 reaches the second installation height of the pressure sensor 14, the light blocking device 17 is also at the height of the pressure sensor 14 to apply a pressure to the pressure sensor 14. Thus, the pressure sensor 14 monitors the pressure change caused by the light blocking device 17 (the pressure change means that when the light blocking device 17 is at the height of the pressure sensor 14, the pressure detected by the pressure sensor 14 is necessarily different from the pressure when the light blocking device 17 is higher than the pressure sensor 14). Thus, the pressure sensor 14 is triggered. At this time, the liquid level of the abrasive liquid in the first container 10 is the second preset liquid level height.

[0044] It should be noted that although there is a difference in height between the liquid level sensor 12 and the optical sensor 13 in the attached Figures 1 to 3 This is only for facilitating the display that the abrasive liquid titration device includes two monitoring devices at the first installation height, and does not mean that the heights of the first monitoring device and the second monitoring device are different. In practice, the first monitoring device and the second monitoring device are arranged at two positions at the same height. Further, the first monitoring device and the second monitoring device can be arranged on the inner side wall or the outer side wall of the first container 10 or on the drainage component 16.

[0045] In this embodiment, the second installation height is lower than the first installation height, that is, the pressure sensor 14 is closer to the bottom of the first container 10 than the liquid level sensor 12 and the optical sensor 13. The first preset liquid level height and the second preset liquid level height are both the alarm heights of the abrasive liquid level in the first container 10, and the first preset liquid level height and the second preset liquid level height can be set according to the different bottom areas of the first container 10 and different titration ratios. For example, it can be set that the amount of abrasive liquid in the first container 10 required for five titrations is the first alarm amount, and the amount of abrasive liquid in the first container 10 required for two titrations is the second alarm amount. Then, according to the set first alarm amount, second alarm amount and the bottom area of the first container 10, the corresponding first preset liquid level height and second preset liquid level height are calculated and monitoring devices at the corresponding heights are installed. Subsequently, when the monitoring device at the first installation height is triggered, it can be considered that the amount of abrasive liquid in the first container 10 is the first alarm amount, that is, the abrasive liquid in the first container 10 is empty after five more titrations. When the monitoring device at the second installation height is triggered, it can be considered that the amount of abrasive liquid in the first container 10 is the second alarm amount, that is, the abrasive liquid in the first container 10 is empty after two more titrations.

[0046] Since a relatively large first preset liquid level height and a relatively small second preset liquid level height are set in this embodiment, and two monitoring devices are set at the first preset liquid level height. Therefore, when the abrasive liquid reaches the first preset liquid level height, as Figure 2 shown, under normal circumstances, the first monitoring device and the second monitoring device at the first installation height should be triggered simultaneously to indicate that the amount of abrasive liquid in the first container 10 is the set first alarm amount. If only one monitoring device is triggered, check the other monitoring device at the first installation height. When the abrasive liquid reaches the second preset liquid level height, as Figure 3 shown, under normal circumstances, the third monitoring device at the second installation height should be triggered to indicate that the amount of abrasive liquid in the first container 10 is the set second alarm amount. If it is not triggered, since the liquid level of the abrasive liquid first passes through the first installation height and then passes through the second installation height, the remaining amount of the abrasive liquid can be monitored according to the triggering results of the two monitoring devices at the first installation height, and the triggering timing of the third monitoring device at the second installation height can be roughly estimated according to the triggering results of the two monitoring devices at the first installation height. If it is not triggered for a long time, check the third monitoring device. In addition, if the third monitoring device at the second installation height has been triggered, while the two monitoring devices at the first installation height have not been triggered or not all triggered, check these untriggered monitoring devices.

[0047] In this embodiment, when the monitoring device is triggered to indicate that the amount of abrasive liquid in the first container 10 is the alarm amount, its corresponding meaning generally means that the abrasive liquid is too little and a liquid addition is prompted. In other embodiments, the alarm amount can also be set to correspond to different meanings and operations.

[0048] The abrasive liquid titration device of this embodiment further includes: an isolation cover 19, which is cup-shaped and buckled in the first container 10. The bottom of the isolation cover 19 communicates with the first container 10. The drainage component 16 passes through the top of the isolation cover 19, and the first end of the drainage component 16 is connected to the top of the isolation cover 19 without a gap. When the abrasive liquid enters the first container 10 from the liquid inlet 11 at the top of the first container 10, it flows to the top of the isolation cover 19 through the first end of the drainage component 16, and then flows to the bottom of the first container 10 through the outer wall of the isolation cover 19. The isolation cover 19 further buffers the abrasive liquid to prevent splashing. Also, since the isolation cover 19 blocks most of the bottom of the first container 10, it prevents the abrasive liquid from splashing upward out of the first container 10 after flowing into the bottom of the first container 10. And because the bottom of the first container 10 and the bottom of the isolation cover 19 are communicated, based on the principle of the communicating vessel, the liquid level of the abrasive liquid in the isolation cover 19 is kept consistent with the liquid level of the abrasive liquid in the first container 1.

[0049] Further, the light-blocking device 17 is arranged in the isolation cover 19 and surrounds the drainage component 16, so as not to affect the normal operation of the monitoring device for monitoring the liquid level of the abrasive liquid based on the light-blocking device 17.

[0050] As Figures 1 to 3 shown, a filter layer 18 is further provided between the outer wall of the isolation cover 19 and the inner wall of the first container 10. Thus, the abrasive liquid entering the first container 10 can flow into the bottom of the first container 10 only after passing through the filter layer 18. On the one hand, the filter layer 18 can filter impurities in the abrasive liquid entering the bottom of the first container 10. On the other hand, it can effectively prevent particles from falling into the abrasive liquid from the top of the first container 10 during the liquid adding process, thereby preventing the phenomenon that the liquid supply port 15 at the bottom of the first container 10 and the subsequent liquid pipeline are blocked.

[0051] In this embodiment, three monitoring devices are provided, namely a liquid level sensor 12, an optical sensor 13, and a pressure sensor 14. However, the number and types of the monitoring devices provided are not limitations to the present invention. In other embodiments, two monitoring devices with different installation heights can be provided, or the types of the monitoring devices can be the same or different. And in order to minimize the probability of errors occurring in the monitoring devices simultaneously, at least one monitoring device is selected to monitor the liquid level of the abrasive liquid based on the light-blocking device 17. For example, one liquid level sensor and one optical sensor are selected and set at different installation heights according to different preset liquid level heights, or one liquid level sensor and one pressure sensor are selected, or one optical sensor and one pressure sensor are selected, or two optical sensors or two pressure sensors are selected. Or sensors based on other principles can also be selected, but it is necessary to ensure that at least one monitoring device monitors the liquid level of the abrasive liquid based on the light-blocking device 17.

[0052] Furthermore, in another embodiment, multiple monitoring devices can also be provided. When the number of the monitoring devices is at least three, more preset liquid level heights can be set, but the number of the preset liquid level heights should be less than the number of the monitoring devices, so that at least two of the monitoring devices can be set at the same installation height corresponding to the same preset liquid level height.

[0053] In yet another embodiment, at least one monitoring device is provided on the drainage component 16, and other monitoring devices can be provided on the inner sidewall or the outer sidewall of the first container 10, or can also be provided on the drainage component 16.

[0054] The present invention also provides a liquid level detection method, which uses the above-mentioned abrasive liquid titration device. The method includes the following steps:

[0055] S1. Set the installation heights of the three monitoring devices on the inner part and the sidewall of the first container 10 according to two preset liquid level heights of the abrasive liquid;

[0056] In this embodiment, two preset liquid level heights and three monitoring devices are set. The first preset liquid level height corresponds to the first installation height, and two monitoring devices are installed at the first installation height, namely the liquid level sensor 12 and the optical sensor 13, and the liquid level sensor 12 and the optical sensor 13 are installed on the inner sidewall or the outer sidewall of the first container 10; the second preset liquid level height corresponds to the second installation height, and one monitoring device is installed at the second installation height, namely the pressure sensor 14, and the pressure sensor 14 is installed on the drainage component 16 inside the first container 10.

[0057] In other embodiments, at least two monitoring devices may be provided, and the installation heights of these monitoring devices are set according to at least two preset liquid level heights. These monitoring devices may be provided on the inner and outer side walls of the first container 10 or inside the first container 10.

[0058] S2. Add the grinding liquid into the first container 10 from the liquid inlet 11 of the first container 10, so that the grinding liquid flows through the first end of the drainage member 16 and the outer side wall of the isolation cover 19 to the bottom of the first container 10 until the liquid level height of the grinding liquid in the first container 10 is greater than the maximum preset liquid level height.

[0059] S3. Control the grinding liquid to flow out from the liquid supply port 15 at the bottom of the first container 10. When the grinding liquid in the first container 10 decreases to the preset liquid level height, the monitoring device at the corresponding height is triggered.

[0060] In this embodiment, as the grinding liquid decreases, when the liquid level of the grinding liquid in the first container 10 reaches the first preset liquid level height, the liquid level sensor 12 and the optical sensor 13 at the first installation height are triggered, indicating that the liquid level of the grinding liquid reaches the first preset liquid level height. At this time, if the liquid level sensor 12 and the optical sensor 13 are not triggered simultaneously, check the untriggered monitoring device.

[0061] As the grinding liquid continues to decrease, when the liquid level of the grinding liquid in the first container 10 reaches the second preset liquid level height, the pressure sensor 14 at the second installation height is triggered, indicating that the liquid level of the grinding liquid reaches the second preset liquid level height. If the pressure sensor 14 at the second preset liquid level height is triggered and the liquid level sensor 12 and the optical sensor 13 at the first preset liquid level height have not been triggered, check the liquid level sensor 12 and the optical sensor 13.

[0062] In other embodiments, when there are multiple monitoring devices and multiple preset liquid level heights, if there is more than one monitoring device at the same installation height (preset liquid level height), if the monitoring devices with the same installation height are not triggered simultaneously, check the untriggered monitoring device. If the monitoring device corresponding to the smaller preset liquid level height is triggered while the monitoring devices corresponding to the larger preset liquid level height are not all triggered, check the untriggered monitoring devices corresponding to the larger preset liquid level height.

[0063] Although the content of the present invention has been described in detail through the above optional embodiments, it should be understood that the above description should not be construed as a limitation of the present invention. After those skilled in the art have read the above content, various modifications and substitutions to the present invention will be obvious. Therefore, the protection scope of the present invention should be defined by the appended claims.

Claims

1. A grinding fluid titration device, characterized in that, it includes: A first container for containing grinding fluid; At least two monitoring devices are arranged inside and / or on the side wall of the first container for monitoring the liquid level of the grinding fluid in the first container; the installation height of the monitoring devices is set corresponding to at least two preset heights of the liquid level of the grinding fluid, so that when the liquid level of the grinding fluid in the first container is at the installation height, the corresponding monitoring device is triggered; A light-blocking device floating on the surface of the grinding fluid; wherein, at least one of the monitoring devices monitors the liquid level of the grinding fluid based on the light-blocking device.

2. The grinding fluid titration device according to claim 1, characterized in that, when there are at least three monitoring devices, two of the monitoring devices correspond to the same preset liquid level height and are arranged at the same height.

3. The grinding fluid titration device according to claim 1, characterized in that, the monitoring device at least includes any one or more of a pressure sensor, a liquid level sensor or an optical sensor; if the monitoring device is a pressure sensor, when the light-blocking device reaches the height of the pressure sensor, the pressure sensor is triggered; if the monitoring device is a liquid level sensor, when the liquid level of the grinding fluid reaches the height of the liquid level sensor, the liquid level sensor is triggered; if the monitoring device is an optical sensor, when the light-blocking device reaches the height of the optical sensor, the optical sensor is triggered.

4. The grinding fluid titration device according to claim 1, characterized in that, the top of the first container is provided with a liquid inlet for adding grinding fluid into the first container; the bottom of the first container is provided with a liquid supply port for supplying grinding fluid to the outside.

5. The grinding fluid titration device according to claim 1, characterized in that, the side wall of the first container includes an inner side wall and an outer side wall.

6. The grinding fluid titration device according to claim 4, characterized in that, a drainage component is vertically arranged in the first container for guiding the grinding fluid to flow into the first container, the first end of the drainage component is located at the liquid inlet, and the second end of the drainage component is fixed at the bottom of the first container.

7. The grinding fluid titration device according to claim 6, characterized in that, at least one of the monitoring devices is arranged on the drainage component.

8. The grinding fluid titration device according to claim 7, characterized in that, a pressure sensor is arranged as the monitoring device at the second end of the drainage component.

9. The grinding fluid titration device according to claim 6, characterized in that, the monitoring device is arranged on the side wall of the first container or on the drainage component.

10. The grinding fluid titration device according to claim 6, characterized in that, it further includes: An isolation cover is buckled inside the first container, the bottom of the isolation cover is communicated with the first container, the drainage component passes through the top of the isolation cover, and the first end of the drainage component is connected to the top of the isolation cover, so that after the grinding fluid enters from the liquid inlet, it sequentially passes through the first end of the drainage component and the outer side wall of the isolation cover and flows to the bottom of the first container.

11. The abrasive liquid titration device according to claim 10, characterized in that, the light-blocking device is arranged around the drainage component and is arranged in the isolation cover.

12. The abrasive liquid titration device according to claim 10, characterized in that, a filter layer is arranged between the outer wall of the isolation cover and the inner wall of the first container.

13. The abrasive liquid titration device according to claim 1, characterized in that, the liquid inlet of the first container is funnel-shaped.

14. The abrasive liquid titration device according to claim 1, characterized in that, the density of the light-blocking device is less than the density of the abrasive liquid and the density of the light-blocking device is uniform.

15. A liquid level detection method, using the abrasive liquid titration device according to any one of claims 1-14, characterized in that, comprising the steps of: setting the installation height of the monitoring device according to at least two liquid level preset heights of the abrasive liquid on the inside and / or side wall of the first container; adding the abrasive liquid into the first container so that the abrasive liquid flows to the bottom of the first container; controlling the abrasive liquid to flow out from the bottom of the first container, and when the abrasive liquid in the first container is reduced to the liquid level preset height, the monitoring device at the corresponding height is triggered; wherein, before the abrasive liquid flows out from the bottom of the first container, the liquid level height of the abrasive liquid in the first container is greater than the maximum liquid level preset height.

16. The liquid level detection method according to claim 15, characterized in that, when the monitoring devices with the same installation height are not triggered simultaneously, check the untriggered monitoring devices.

17. The liquid level detection method according to claim 15, characterized in that, when the monitoring device corresponding to the smaller liquid level preset height is triggered, while the monitoring devices corresponding to the larger liquid level preset heights are not all triggered, check the untriggered monitoring devices corresponding to the larger liquid level preset heights.

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