阅读说明：本技术 液位检测方法、研磨液调和桶以及研磨液调和系统 (Liquid level detection method, grinding fluid mixing barrel and grinding fluid mixing system ) 是由 杨钰 赵正元 李虎 于 2020-06-29 设计创作，主要内容包括：本发明提供了一种液位检测方法、研磨液调和桶以及研磨液调和系统,所述液位检测方法用于检测调和液中的液位信息,所述液位检测方法包括以下步骤：提供一参考物,所述参考物具有上表面；将所述参考物放置于所述调和液中,所述参考物被配置为随所述调和液的液面变化而改变竖向位置,且所述上表面保持高于所述调和液的液面；利用液位传感器检测所述参考物的上表面的位置信息；基于所述上表面的位置信息获取所述调和液的液位信息。如此配置,有效的避免了气泡或者其他变量的影响,从而可以精准的确定调和液的液位高度,准确掌控调和配比,减少了调和液在调和桶中调和时的误差,进而增加了良品率。(The invention provides a liquid level detection method, a grinding fluid mixing barrel and a grinding fluid mixing system, wherein the liquid level detection method is used for detecting liquid level information in a mixed fluid and comprises the following steps: providing a reference object, wherein the reference object is provided with an upper surface; placing the reference in the prepared liquid, the reference being configured to change vertical position as the liquid level of the prepared liquid changes, and the upper surface remaining above the liquid level of the prepared liquid; detecting position information of an upper surface of the reference object by using a liquid level sensor; and acquiring the liquid level information of the mixed liquid based on the position information of the upper surface. So dispose, the effectual influence of having avoided bubble or other variables to the liquid level height of definite blend liquid that can be accurate, the accurate mediation ratio of controlling has reduced the error of blend liquid when mediation in the blending barrel, and then has increased the yields.)

1. A liquid level detection method is used for detecting liquid level information in a mixed liquid, and is characterized by comprising the following steps:

providing a reference object, wherein the reference object is provided with an upper surface;

placing the reference in the prepared liquid, the reference being configured to change vertical position as the liquid level of the prepared liquid changes, and the upper surface remaining above the liquid level of the prepared liquid;

detecting position information of an upper surface of the reference object by using a liquid level sensor;

and acquiring the liquid level information of the mixed liquid based on the position information of the upper surface.

2. The liquid level detection method according to claim 1, wherein the step of obtaining the liquid level information of the blending liquid based on the position information of the upper surface includes:

and determining the liquid level information of the mixed liquid according to the position information of the upper surface and the distance difference between the upper surface and the liquid level of the mixed liquid.

3. The method of claim 2, further comprising:

setting a target liquid level of the mixed liquid, and determining the distance difference between the upper surface and the liquid level of the mixed liquid;

setting the sum of the target liquid level and the distance difference as a reference liquid level;

and when the upper surface is not lower than the reference liquid level, the liquid level sensor acquires a position signal.

4. A method as claimed in claim 3, wherein the height of the reference level is less than twice the height of the target level.

5. A grinding fluid blending barrel is characterized by comprising: the device comprises a blending barrel body, a liquid level sensor and a reference object;

the blending barrel body is used for containing blending liquid;

the liquid level sensor is used for acquiring liquid level information of the blending liquid, the reference object is arranged in the blending barrel body and is configured to change the vertical position along with the change of the liquid level of the blending liquid, and the upper surface of the reference object is kept higher than the liquid level of the blending liquid.

6. The lapping liquid tempering tank of claim 5, wherein said reference is a solid reference having a density less than a density of said tempering liquid.

7. The slurry tempering tank of claim 6, wherein a target level of said tempering liquid is set, and a difference in distance of said upper surface from said level of said tempering liquid is determined; setting the sum of the target liquid level and the distance difference as a reference liquid level; the height of the solid reference is less than the height of the reference level.

8. The slurry tempering tank according to claim 5, further comprising a slide bar vertically disposed inside said tempering tank body, said reference being movably disposed on said slide bar along an extension direction of said slide bar, said slide bar limiting said reference to have only a vertical degree of freedom.

9. The slurry tempering tank of claim 8, wherein said slurry tempering tank comprises two slide bars spaced radially of said tempering tank body, said reference being simultaneously slidably connected to said two slide bars.

10. A slurry conditioning system comprising a slurry conditioning tank according to any one of claims 5 to 9, a controller and an inlet means;

the liquid level sensor of the grinding liquid mixing barrel is in communication connection with the controller, and when the liquid level height detected by the liquid level sensor is not lower than a set reference height, the liquid level sensor is configured to: acquiring a in-place signal and sending the in-place signal to the controller;

the controller with inlet means communication connection, after the controller received information in place, inlet means closed.

Technical Field

The invention relates to the technical field of liquid level blending control, in particular to a liquid level detection method, a grinding fluid blending barrel and a grinding fluid blending system.

Background

Integrated circuit chips are formed by building multiple stacks of materials and components on a semiconductor substrate. The grinding fluid is used as an important material in the integrated circuit manufacturing process, and the blending ratio of the grinding fluid in the blending barrel has an important influence on the subsequent process of the product.

At present, a liquid level sensor commonly used in a grinding liquid mixing barrel is an infrared liquid level controller, and the infrared liquid level controller utilizes the refraction and reflection principles of light rays to enable the light rays to be reflected or refracted on an interface of two different media, and utilizes light with different intensities to determine whether the grinding liquid reaches a set liquid level height, namely a target liquid level, so as to control a photoelectric switch of the infrared liquid level controller and further control the switch of a liquid inlet valve of the mixing barrel. Specifically, as shown in fig. 1, fig. 1 is a schematic diagram of a grinding fluid mixing barrel in the prior art. When the liquid level 10 of the grinding liquid is higher than the photoelectric switch 20, the grinding liquid and the photoelectric switch 20 form one interface, when the liquid level 10 of the grinding liquid is lower than the photoelectric switch 20, the air and the photoelectric switch 20 form another interface, and the two interfaces enable the light received by the light inside the photoelectric switch to have different reflected light intensities, namely correspond to two different switch states, so that the switch of the liquid inlet valve is controlled.

However, when a plurality of solutions in the grinding fluid mixing barrel are mixed according to the volume ratio, when the liquid level is lower than the target liquid level controlled by the infrared ray, the liquid inlet valve is always opened; when the liquid level reaches the target liquid level controlled by the infrared ray, the liquid inlet valve can be automatically closed. If there is the bubble to produce when the feed liquor, float the bubble on liquid and can produce the mistake interference to the accurate judgement of liquid level, especially when liquid viscosity is great, float bubble on the liquid level probably can be many, the feed liquor valve is just closed when the infrared ray detects the bubble, can lead to the mediation ratio of different solutions to change in the lapping liquid tempering tank like this, and then lead to the process grinding rate that relies on these solutions, the sculpture is than etc. and change, light then lead to the product yield to reduce, heavy then probably leads to the product directly to scrap.

Therefore, it is a problem to be solved to develop a method for precisely controlling the liquid level height by avoiding the interference of bubbles generated during the liquid blending process, and reducing the error of the blending liquid in the blending tank.

Disclosure of Invention

The invention aims to provide a liquid level detection method, a grinding fluid mixing barrel and a grinding fluid mixing system, and aims to solve the problem that mixing proportion has errors due to bubble interference when liquid is mixed in the conventional mixing barrel.

In order to solve the technical problem, the invention provides a liquid level detection method for detecting liquid level information in a mixed liquid, which comprises the following steps: providing a reference object, wherein the reference object is provided with an upper surface; placing the reference in the prepared liquid, the reference being configured to change vertical position as the liquid level of the prepared liquid changes, and the upper surface remaining above the liquid level of the prepared liquid; detecting position information of an upper surface of the reference object by using a liquid level sensor; and acquiring the liquid level information of the mixed liquid based on the position information of the upper surface.

Optionally, the step of obtaining the liquid level information of the blending liquid based on the position information of the upper surface includes: and determining the liquid level information of the mixed liquid according to the position information of the upper surface and the distance difference between the upper surface and the liquid level of the mixed liquid.

Optionally, the liquid level detection method further includes: setting a target liquid level of the mixed liquid, and determining the distance difference between the upper surface and the liquid level of the mixed liquid; setting the sum of the target liquid level and the distance difference as a reference liquid level; and when the upper surface is not lower than the reference liquid level, the liquid level sensor acquires a position signal.

Optionally, the height of the reference liquid level is less than twice the height of the target liquid level.

In order to solve the above technical problem, the present invention further provides a grinding fluid blending tank, comprising: the device comprises a blending barrel body, a liquid level sensor and a reference object; the blending barrel body is used for containing blending liquid; the liquid level sensor is used for acquiring liquid level information of the mixed liquid; the reference object is arranged in the blending barrel body and is configured to change the vertical position along with the change of the liquid level of the blending liquid, and the upper surface of the reference object is kept higher than the liquid level of the blending liquid.

Optionally, the reference is a solid reference, and the density of the solid reference is less than that of the concoction liquid.

Optionally, a target liquid level of the mixed liquid is set, and a distance difference between the upper surface and the liquid level of the mixed liquid is determined; setting the sum of the target liquid level and the distance difference as a reference liquid level; the height of the solid reference is less than the height of the reference level.

Optionally, the grinding fluid blending barrel further comprises a slide bar, the slide bar is vertically arranged inside the blending barrel body, the reference object is movably arranged on the slide bar along the extending direction of the slide bar, and the slide bar limits that the reference object only has a degree of freedom along the vertical direction.

Optionally, the grinding fluid mixing barrel comprises two slide bars, the two slide bars are arranged along the radial direction of the mixing barrel body at intervals, and the reference object is connected with the two slide bars in a sliding manner.

In order to solve the technical problem, the invention also provides a grinding fluid mixing system, which comprises the grinding fluid mixing barrel, a controller and a liquid inlet device; the liquid level sensor of the grinding liquid mixing barrel is in communication connection with the controller, and when the liquid level height detected by the liquid level sensor is not lower than a set reference height, the liquid level sensor is configured to: acquiring a in-place signal and sending the in-place signal to the controller; the controller with inlet means communication connection, after the controller received information in place, inlet means closed.

In the liquid level detection method, the grinding fluid mixing barrel and the grinding fluid mixing system provided by the invention, the liquid level detection method is used for detecting liquid level information in the mixing fluid, and the liquid level detection method comprises the following steps: providing a reference object, wherein the reference object is provided with an upper surface; placing the reference in the prepared liquid, the reference being configured to change vertical position as the liquid level of the prepared liquid changes, and the upper surface remaining above the liquid level of the prepared liquid; detecting position information of an upper surface of the reference object by using a liquid level sensor; and acquiring the liquid level information of the mixed liquid based on the position information of the upper surface. With this configuration, the liquid level of the mixed liquid is estimated by detecting the position information of the upper surface of the reference object in the mixed liquid by the liquid level sensor. The effectual influence of avoiding bubble or other variables, and then make the positional information that detects the upper surface that level sensor can be accurate to the liquid level height of definite blend liquid that can be accurate, the accurate mediation ratio of controlling has reduced the error of blend liquid when mediating in the blending barrel, and then has increased the yields.

Drawings

It will be appreciated by those skilled in the art that the drawings are provided for a better understanding of the invention and do not constitute any limitation to the scope of the invention. Wherein:

FIG. 1 is a schematic view of a prior art slurry conditioner bowl;

FIG. 2 is a schematic diagram of a liquid level detection method according to an embodiment of the invention;

fig. 3 is a schematic view of a slurry mixing barrel according to an embodiment of the invention.

In the drawings:

10-grinding liquid level, 20-photoelectric switch;

100-reference, 110-upper surface;

200-concoction liquid, 210-bubble;

300-a liquid level sensor; 400-a blending barrel body; 500-a slide bar; 600-stirring rod.

Detailed Description

To further clarify the objects, advantages and features of the present invention, a more particular description of the invention will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. It is to be noted that the drawings are in greatly simplified form and are not to scale, but are merely intended to facilitate and clarify the explanation of the embodiments of the present invention. Further, the structures illustrated in the drawings are often part of actual structures. In particular, the drawings may have different emphasis points and may sometimes be scaled differently.

As used in this specification, the singular forms "a," "an," and "the" include plural referents unless the content clearly dictates otherwise. As used in this specification, the term "or" is generally employed in its sense including "and/or" unless the content clearly dictates otherwise.

The embodiment of the invention provides a liquid level detection method, a grinding fluid mixing barrel and a grinding fluid mixing system, which is characterized in that: the liquid level detection method comprises the steps of detecting position information of the upper surface of a reference object in the mixed liquid by using a liquid level sensor so as to calculate the liquid level height of the mixed liquid; the effectual bubble of having avoided disturbs, and the liquid level height of accurate control concoction liquid has reduced the error of concoction liquid when concocting in the blending barrel.

The embodiment of the invention provides a liquid level detection method, a grinding fluid mixing barrel and a grinding fluid mixing system, wherein the liquid level detection method is used for detecting liquid level information in a mixed fluid and comprises the following steps: providing a reference object, wherein the reference object is provided with an upper surface; placing the reference in the prepared liquid, the reference being configured to change vertical position as the liquid level of the prepared liquid changes, and the upper surface remaining above the liquid level of the prepared liquid; detecting position information of an upper surface of the reference object by using a liquid level sensor; and acquiring the liquid level information of the mixed liquid based on the position information of the upper surface. Further, the grinding fluid blending barrel comprises: the device comprises a blending barrel body, a liquid level sensor and a reference object; the blending barrel body is used for containing blending liquid; the liquid level sensor is arranged inside the blending barrel body; the reference object is arranged in the blending barrel body and is configured to change the vertical position along with the change of the liquid level of the blending liquid, and the upper surface of the reference object is kept higher than the liquid level of the blending liquid; the liquid level sensor is used for acquiring liquid level information of the blending liquid. The liquid level sensor is used for detecting the position information of the upper surface of the reference object in the mixed liquid so as to calculate the liquid level height of the mixed liquid; the effectual influence of avoiding bubble or other variables, and then make the positional information that detects the upper surface that level sensor can be accurate to the liquid level height of definite blend liquid that can be accurate, the accurate mediation ratio of controlling has reduced the error of blend liquid when mediating in the blending barrel, and then has increased the yields. Further, the grinding fluid mixing barrel further comprises a sliding rod, and resistance when the reference object rises is reduced by the sliding rod. The grinding fluid blending system further comprises a controller, wherein a liquid level sensor of the grinding fluid blending barrel is electrically connected with the controller, and when the liquid level height detected by the liquid level sensor is not lower than a set reference height, the liquid level sensor sends a signal of liquid level information to the controller; the controller with the inlet means electricity is connected for control inlet means's switch, and then the feed liquor of control blend liquid that can be nimble has improved the mediation precision.

The following description refers to the accompanying drawings.

FIG. 2 is a schematic diagram of a liquid level detection method according to an embodiment of the present invention; fig. 3 is a schematic view of a polishing slurry mixing barrel according to an embodiment of the invention.

Referring to fig. 2 to 3, the liquid level detection method is used to detect the liquid level information in the blending liquid. The liquid level detection method comprises the following steps:

s1: a reference 100 is provided, the reference 100 having an upper surface 110. In this embodiment, the reference object 100 is, for example, a block with a rectangular structure, and may also be a trapezoidal block, a cylinder, a truncated cone, etc., and the upper surface 110 is, for example, a flat surface. In other embodiments, the reference 100 may also be a sphere, and the upper vertex of the sphere is set as the upper surface 110 of the reference 100.

S2: placing the reference 100 in the prepared liquid 200, wherein the reference 100 is configured to change vertical position with the liquid level of the prepared liquid 200, and the upper surface 110 is kept higher than the liquid level of the prepared liquid 200. In the embodiment, the density of the reference object 100 is less than that of the blending liquid 200, for example, and the reference object 100 floats or descends vertically in the blending liquid 200 along with the rise or the fall of the liquid level. When the reference object 100 is placed in the prepared liquid 200, the upper surface 110 is kept facing the direction of the liquid surface rise of the prepared liquid 200, and when the prepared liquid 200 rises, the upper surface 100 is higher than the liquid surface of the prepared liquid 200. One skilled in the art can determine the density of the reference 200 by combining the density of the solution 200 and the physical knowledge related to the density. In other embodiments, the reference 200 may also be a combination of two or more different density masses. For example, when the reference 100 is a rectangular block, the rectangular block is combined by two blocks with different densities, as shown in fig. 3, the rectangular block is divided into two parts along the horizontal direction, i.e., an upper part and a lower part, and the density of the upper part block is smaller than that of the lower part block (the upper and lower directions refer to the upper and lower directions in fig. 3). At this time, when the reference 100 is placed in the prepared liquid 200, the surface of the block having a relatively low density in the reference 100 may be used as the upper surface 110. Of course, the rectangular block can also be a block with three different densities, and the person skilled in the art sets the overall density of the rectangular block to be less than the density of the blending liquid by combining the physical knowledge related to the densities, and judges and determines the floating condition of the block in the blending liquid according to the internal density condition of the rectangular block to determine the upper surface 110 of the rectangular block. The volume of the reference 100 can be flexibly selected by those skilled in the art according to physicochemical properties such as viscosity, density, and degree of easy bubble generation of the solution 200. By selecting the density and volume of the reference 100, the reference 100 can float upwards in the blending liquid 200.

S3: the position information of the upper surface 110 of the reference 100 is detected using the level sensor 300. Because the blending liquid 200 can generate the bubbles 210 in the blending process, the bubbles 210 can affect the detection precision of the liquid level sensor 300, and further affect the blending proportion of the blending liquid 200, and further cause the process grinding rate, the etching ratio and the like depending on the solutions to change, so that the product yield is reduced if the process grinding rate, the etching ratio and the like are reduced, and the product is possibly directly scrapped if the process grinding rate, the etching ratio and the like are high. Adopt level sensor 300 to detect upper surface 110, upper surface 110 is a fixed structural plane, the structural plane can not change along with the change of concoction liquid 200, the effectual influence of avoiding bubble or other variables to avoided the mistake of concoction liquid 200 surface bubble to disturb effectively, improved level sensor 300's detection precision, and then make level sensor 300 can be accurate detect the positional information of upper surface 110. The liquid level sensor 300 is, for example, an infrared liquid level controller, and detects position information of the upper surface 100 by using the principle of refraction and reflection of light. In other embodiments, the liquid level sensor 300 is another detecting sensor for detecting the position information of the object, and those skilled in the art can set the detecting sensor according to actual requirements.

S4: the liquid level information of the prepared liquid 200 is acquired based on the position information of the upper surface 110. Preferably, the liquid level information of the mixed liquid 200 is determined according to the position information of the upper surface 110 and the distance difference between the upper surface 110 and the liquid level of the mixed liquid 200. In this embodiment, after the position information of the upper surface 110 is detected by the liquid level sensor 300, the liquid level height of the blending liquid 200 can be accurately determined according to the position relationship between the reference object 100 and the liquid level of the blending liquid 200, the blending ratio can be controlled, the blending error of the blending liquid in the blending barrel is reduced, and the yield is increased. For example, the liquid level sensor 300 detects that the position information of the upper surface 110 is H1, and the liquid level difference between the upper surface 110 and the prepared liquid 200 is H2, so that the liquid level of the prepared liquid 200 is H1-H2. Wherein, the liquid level difference H2 between the upper surface 100 and the mixed liquid 200 can be determined by those skilled in the art according to physical knowledge.

In the liquid level detection method provided in the present embodiment, the liquid level of the prepared liquid 200 is calculated by detecting the position information of the upper surface 110 of the reference object 100 in the prepared liquid 200 by the liquid level sensor 300. The effectual influence of avoiding bubble or other variables, and then make level sensor 300 can be accurate detect the positional information of upper surface 110 to the liquid level height of definite blend liquid 200 that can be accurate, the accurate control is transferred the ratio, has reduced the error of blend liquid when mediating in the mediation bucket, and then has increased the yields.

Further, during blending, the blended liquid 200 includes different types of blended liquids, and different volumes of the blended liquids need to be set according to different ratios, so that the liquid level height of each blended liquid 200 needs to be determined (it is understood that the liquid level height is in a proportional relationship with the volume of the liquid), and when different blended liquids 200 are added, a target liquid level (i.e., a target volume, i.e., L1) of each blended liquid 200 needs to be set. In order to determine the target level information of the prepared liquid 200 (in the prior art, the target level is set to be at the lower surface of the liquid level sensor 300), the reference level (L) of the upper surface may be determined according to the distance difference (H2) of the upper surface 110 from the liquid level of the prepared liquid 200, as described above, and the liquid level detection method further includes: setting a target liquid level of the mixed liquid 200 (L1), and determining a distance difference of the upper surface 110 from the liquid level of the mixed liquid 200 (H2); setting the sum of the target liquid level (L1) and the distance difference (H2) as a reference liquid level (L), i.e., L1+ H2.

It should be noted that, preferably, when the upper surface 110 is not lower than the reference level (L), the level sensor 300 obtains a position signal to indicate that the upper surface 110 has reached the reference level, and thus that the blended liquid 200 has reached the target level. Further, when the upper surface 110 is not lower than the reference liquid level, the liquid level sensor 300 acquires in-place information, and can also avoid the phenomenon of false detection when the reference object 100 is not vertically displaced when the mixed liquid 200 is at a low liquid level, so that the target liquid level (L1) of the mixed liquid 200 can be accurately judged.

Furthermore, in order to improve the detection sensitivity of the liquid level sensor 300, the height of the reference liquid level is preferably less than twice the height of the target liquid level, that is, the distance from the upper surface 110 of the reference object 100 to the target liquid level is less than the height of the target liquid level, so as to prevent the upper surface 110 of the reference object 100 from shaking in the mixed liquid 200 to cause detection errors. The height of the reference liquid level is 1.2 times of the height of the target liquid level, and the distance from the upper surface 110 to the target liquid level is 0.2 times of the height of the target liquid level, so that the reference object 100 is more stable in the blending liquid 200, the upper surface 110 is prevented from deviating from the target liquid level too much to cause error detection, and the detection sensitivity of the liquid level sensor 300 is effectively improved.

The present invention also provides a slurry mixing barrel, as shown in fig. 3, comprising: a tempering tank 400, a level sensor 300, and a reference 100.

The blending barrel 400 is, for example, a cylindrical barrel, and is used for accommodating the blending liquid 200; in other embodiments, the shape of the tempering tank body 400 is not limited as long as the tempering liquid 200 can be accommodated.

The liquid level sensor 300 is disposed inside the tempering tub 400, for example, and is used for detecting liquid level information of the upper surface 110; preferably, the liquid level sensor 300 is disposed on a side wall inside the blending barrel 400, and in other embodiments, the liquid level sensor 300 may further dispose the liquid level sensor 400 at an intermediate position inside the blending barrel 400 through the erection of a bracket so as to detect the position of the upper surface 110. Of course, the specific position of the liquid level sensor 300 may also be other positions, and those skilled in the art can set the position according to actual needs, which is not limited herein.

The reference 100 is disposed in the blending tub body 400 and configured to change a vertical position according to a change in a liquid level of the blending liquid 200, and an upper surface 110 of the reference 100 is maintained to be higher than the liquid level of the blending liquid 200. The liquid level sensor 300 is used for acquiring the liquid level information of the mixed liquid 200. Please refer to the above description for the selection of the reference 100 and the position of the reference 100 in the prepared liquid 200; for the specific situation that the liquid level sensor 100 obtains the liquid level information of the blending liquid 200, please refer to the above description, which is not repeated herein.

In the polishing slurry mixing barrel provided by the embodiment, the mixing barrel body 400, the liquid level sensor 300 and the reference 100 are arranged; the blending barrel body 400 is used for accommodating a blending liquid 200; the liquid level sensor 300 is disposed inside the blending barrel 400; the reference 100 is arranged in the blending barrel body 400 and is configured to change the vertical position along with the change of the liquid level of the blending liquid 200, and the upper surface 110 of the reference 100 is kept higher than the liquid level of the blending liquid 200; the liquid level sensor 300 is used for acquiring the liquid level information of the mixed liquid 200. The liquid level of the prepared liquid 200 is calculated by detecting the position information of the upper surface 110 of the reference object 100 in the prepared liquid 200 by the liquid level sensor 300. The effectual influence of avoiding bubble or other variables, and then make level sensor 300 can be accurate detect the positional information of upper surface 110 to the liquid level height of definite blend liquid 200 that can be accurate, the accurate control is transferred the ratio, has reduced the error of blend liquid when mediating in the mediation bucket, and then has increased the yields.

Preferably, the reference 100 is a solid reference having a density less than the density of the blended liquid 200. In this embodiment, the reference object 100 is a rectangular block with one density, and in other embodiments, the reference object 100 may be an object with two densities, or a combination of objects with multiple densities.

Further, setting a target liquid level of the mixed liquid 200, and determining the distance difference between the upper surface 110 and the liquid level of the mixed liquid 200; setting the sum of the target liquid level and the distance difference as a reference liquid level. Reference liquid level promptly is target liquid level + distance difference, the information of the judgement reference liquid level that can be accurate, and then control target liquid level that can be accurate, has improved the precision of mediation ratio, improves the yields. It should be noted that, in order to avoid measurement errors caused by the fact that the height of the solid reference object is already higher than the height of the reference liquid level when the solid reference object is placed at the bottom of the blending barrel body, the height of the solid reference object is preferably lower than the height of the reference liquid level.

Preferably, as shown in fig. 3, the grinding fluid blending barrel further includes a slide bar 500, the slide bar 500 is vertically disposed inside the blending barrel body 400, the reference is movably disposed on the slide bar 500 along an extending direction of the slide bar 500, and the slide bar 500 limits the reference 100 to have only a vertical degree of freedom. In this embodiment, the sliding rod 500 has two ends, one end of which is connected to the bottom of the blending barrel 400, and the other end of which extends vertically toward the direction in which the liquid level rises. The reference 100 is movable along an extending direction of the slide bar 500, i.e., a vertical direction. Specifically, the sliding bar 500 is, for example, a pulley bar. The arrangement of the reference 100 and the pulley lever can be set by a person skilled in the art according to a conventional arrangement method. At this time, under the action of the sliding rod 500, on one hand, the reference object 100 only has vertical degree of freedom, and on the other hand, when the reference object 100 rises along with the liquid level, the resistance of other directions to the reference object 100 is greatly reduced, so that the reference object 100 can rise sensitively, and the detection accuracy is improved. More preferably, the slurry mixing barrel includes two sliding rods 500, the two sliding rods 500 are spaced apart from each other in a radial direction of the mixing barrel 400, and the reference 100 is simultaneously slidably connected to the two sliding rods 500. In some embodiments, the slide bar 500 may be in other forms, such as a vertical arrangement of three slide bars, which together control the vertical position of the reference 100, or may be in other forms that limit the vertical displacement of the reference 100. Further, the grinding fluid blending barrel further comprises a stirring rod 600 for stirring the blending fluid 200, and the stirring rod can be set by the skilled person according to actual requirements.

The invention also provides a grinding fluid mixing system, which comprises the grinding fluid mixing barrel, a controller (not shown) and a liquid inlet device (not shown) as described above. The liquid level sensor 300 of the grinding fluid mixing barrel is in communication connection with the controller, and when the liquid level detected by the liquid level sensor 300 is not lower than the set reference height, the liquid level sensor 300 is configured to: acquiring a in-place signal and sending the in-place signal to the controller; the controller is in communication connection with the liquid inlet device and is used for controlling the switch of the liquid inlet device. And when the controller receives the in-place information, the liquid inlet device is closed. Those skilled in the art can be according to prior art, will level sensor 300 with the controller carries out the electricity and connects, is connected controller and inlet means electricity, and is concrete, when the liquid level height equals or is higher than the reference height of settlement (the reference height can be the height of reference liquid level above), level sensor 300 conveys the information that detects to the controller, and level sensor 300's information is received to the controller to information to receiving is through comprehensive judgement, for example, through comprehensive judgement, stop inlet means feed liquor, and then close inlet means's switch. When the liquid level sensor 300 detects that the upper surface 110 of the reference object 100 reaches the reference height, the liquid inlet device is automatically closed, so that the false interference of bubbles on the surface of the mixed liquid 200 is effectively avoided. The grinding fluid mixing system has the beneficial effects brought by the grinding fluid mixing barrel, and the details are not repeated herein. The structure and principle of other components of the slurry conditioning system can be referred to in the prior art and will not be described herein.

In summary, in the liquid level detection method, the polishing solution blending tank and the polishing solution blending system provided by the present invention, the liquid level detection method is used for detecting liquid level information in the blending solution, and the liquid level detection method includes the following steps: providing a reference object, wherein the reference object is provided with an upper surface; placing the reference in the prepared liquid, the reference being configured to change vertical position as the liquid level of the prepared liquid changes, and the upper surface remaining above the liquid level of the prepared liquid; detecting position information of an upper surface of the reference object by using a liquid level sensor; and acquiring the liquid level information of the mixed liquid based on the position information of the upper surface. With this configuration, the liquid level of the mixed liquid is estimated by detecting the position information of the upper surface of the reference object in the mixed liquid by the liquid level sensor. The effectual influence of avoiding bubble or other variables, and then make the positional information that detects the upper surface that level sensor can be accurate to the liquid level height of definite blend liquid that can be accurate, the accurate mediation ratio of controlling has reduced the error of blend liquid when mediating in the blending barrel, and then has increased the yields.

The above description is only for the purpose of describing the preferred embodiments of the present invention, and is not intended to limit the scope of the present invention, and any variations and modifications made by those skilled in the art based on the above disclosure are within the scope of the appended claims.