CN-122008423-A - Concentration feedback-based diamond wire cutting cooling liquid proportioning control method and system

CN122008423ACN 122008423 ACN122008423 ACN 122008423ACN-122008423-A

Abstract

The invention belongs to the technical field of diamond wire cutting, and provides a method and a system for controlling the proportion of diamond wire cutting cooling liquid based on concentration feedback, wherein the method comprises the steps of pre-storing target viscosity intervals of different wire diameters and wire speed combinations, constructing a multi-working-condition viscosity library, and obtaining a current working-condition corresponding interval; the method comprises the steps of collecting real-time viscosity and temperature of cooling liquid, converting the viscosity and temperature into a calibrated viscosity value at a standard temperature through a viscosity-temperature curve, calculating the ratio of the calibrated viscosity to the real-time concentration to obtain a functional decline evaluation value, judging whether the functional decline evaluation value is lower than an early warning threshold value, judging that a high polymer chain is in shearing failure if the calibrated viscosity is lower than a lower limit and the evaluation value touches an alarm, calculating the viscosity deviation amount and a compensation increment, regulating the concentration threshold value to obtain a corrected target concentration, increasing the power/duty ratio of a stock solution supply pump, improving the stock solution ratio to compensate the strength of a fluid lubricating film, and adapting to the working condition requirement of high-speed superfine diamond wire cutting.

Inventors

YANG CHANGJIAN
CHEN SIQI
LIU JINGCAI
WANG XUEQIN
Tian Bianbian

Assignees

嘉兴昇望科技有限公司

Dates

Publication Date: 20260512
Application Date: 20260414

Claims (10)

1. The diamond wire cutting cooling liquid proportioning control method based on concentration feedback is characterized by comprising the following steps: s10, pre-storing target viscosity intervals under the combination of different diamond wire diameters and wire speeds, constructing a multi-station target viscosity library, wherein the target viscosity intervals comprise a lower viscosity limit value and an upper viscosity limit value, and acquiring a target viscosity interval corresponding to the current cutting process parameters; s20, collecting a real-time viscosity value and a real-time temperature signal of the cooling liquid in the circulation loop in real time, and converting the real-time viscosity value into a calibrated viscosity value at a standard temperature by utilizing a preset viscosity-temperature characteristic curve; Step S30, calculating the ratio of the calibrated viscosity value to the real-time concentration reading fed back by the online concentration meter to obtain a functional decline evaluation value; Step S40, judging that the cooling liquid polymer chain is in shear failure if the calibrated viscosity value is lower than the viscosity lower limit value and the functional decline evaluation value is lower than the decline early warning threshold value; And S50, increasing the output power or the duty ratio of the stock solution supply pump according to the corrected target concentration value, increasing the proportion of the stock solution in the circulation loop, and improving the physical strength of the compensation fluid lubricating film through solute concentration.
2. The concentration feedback-based diamond wire cutting coolant proportioning control method of claim 1, wherein the specific process of pre-storing target viscosity intervals under the combination of different diamond wire diameters and wire speeds and constructing a multi-station target viscosity library is as follows: And under a standard cutting environment, carrying out a plurality of groups of cutting experiments on different diamond wire diameters, recording viscosity values of the cooling liquid when the total thickness deviation TTV, the wire mark depth and the wire breakage rate of the silicon wafer are all in an optimal range, forming a basic viscosity sample, carrying out gradient weighted correction on the basic viscosity sample by taking the diamond wire speed as a variable, correspondingly increasing a lower viscosity limit value when the wire speed is increased by a preset gradient, establishing a corresponding relation between the diamond wire diameter, the wire speed and the viscosity of the cooling liquid, setting a target viscosity interval for each combination of the wire diameter and the wire speed according to the corresponding relation, integrating the target viscosity interval corresponding to each combination, and constructing and storing a multi-working-condition target viscosity library.
3. The concentration feedback-based diamond wire cutting coolant proportioning control method according to claim 2, wherein the lower viscosity limit value and the upper viscosity limit value are specifically: the lower limit value of the viscosity is the lowest dynamic viscosity which can maintain the lubricating liquid film and avoid the hard friction between diamond particles and the silicon wafer under the corresponding working condition, and the upper limit value of the viscosity is the maximum dynamic viscosity which can ensure that the cooling liquid enters the kerf under the corresponding working condition and does not generate excessive bubbles and silicon powder sedimentation.
4. The method for controlling the proportion of the diamond wire cutting cooling liquid based on concentration feedback according to claim 1, wherein the specific process of obtaining the target viscosity interval corresponding to the current cutting process parameter is as follows: Acquiring currently executing cutting process parameters, wherein the cutting process parameters comprise current diamond wire diameter values and real-time running wire speeds, matching the obtained diamond wire diameter values and the real-time running wire speeds in a multi-working-condition target viscosity library, and calculating a target viscosity interval of the current cutting process parameters by adopting a linear interpolation method when the acquired cutting process parameters are between two preset gradients in the multi-working-condition target viscosity library.
5. The concentration feedback-based diamond wire cutting cooling liquid proportioning control method according to claim 1, wherein the specific process of acquiring the real-time viscosity value and the real-time temperature signal of the cooling liquid in the circulation loop in real time is as follows: The method comprises the steps that an online viscosity detection device and a temperature detection device are installed at a pipeline position, close to a cutting station, of a cooling liquid circulation loop, and real-time viscosity values are collected through the online viscosity detection device; and acquiring real-time temperature signals through a temperature detection device.
6. The concentration feedback-based diamond wire cutting coolant proportioning control method according to claim 1, wherein the specific process of converting the real-time viscosity value into a calibrated viscosity value at a standard temperature by using a preset viscosity-temperature characteristic curve is as follows: Presetting a viscosity-temperature characteristic curve, substituting a temperature signal acquired by a temperature detection device and a real-time viscosity value acquired by a viscosity detection device into the viscosity-temperature characteristic curve to perform numerical conversion to obtain a corresponding viscosity value, and taking the viscosity value as a calibrated viscosity value; the specific process for constructing the viscosity-temperature characteristic curve is as follows: And selecting pure cooling liquid which is in the same batch and does not participate in cutting operation as an experimental sample, detecting the dynamic viscosity value of the cooling liquid at the corresponding experimental temperature at a plurality of set different experimental temperature points, and fitting the acquired multiple groups of temperature and dynamic viscosity data to obtain a viscosity-temperature characteristic curve.
7. The concentration feedback-based diamond wire cutting coolant proportioning control method according to claim 1, wherein the specific process of judging whether the functional degradation evaluation value is lower than a preset degradation early warning threshold value is as follows: Performing ratio operation on the real-time concentration reading and the calibrated viscosity value, taking the calibrated viscosity value as a molecule, taking the real-time concentration reading as a denominator, and dividing the real-time concentration reading and the calibrated viscosity value to obtain a calculation result as a functional decline evaluation value; Comparing the functional decay evaluation value with a preset decay early-warning threshold value, judging that the lubricating function of the cooling liquid is normal if the functional decay evaluation value is larger than or equal to the preset decay early-warning threshold value, and judging that the lubricating function of the cooling liquid is abnormally attenuated if the functional decay evaluation value is lower than the preset decay early-warning threshold value.
8. The concentration feedback-based diamond wire cutting coolant proportioning control method according to claim 1, wherein the specific process of obtaining the corrected target concentration value is as follows: Subtracting the calibrated viscosity value from the lower viscosity value to obtain a viscosity deviation between the calibrated viscosity value and the lower viscosity value, and calculating according to the viscosity deviation by using the formula Calculating to obtain the corresponding viscosity compensation increment to be supplemented, In order to compensate for the increase in viscosity, For the compensation coefficient of the experimental calibration, As the amount of the viscosity deviation, there is provided, And (3) taking the viscosity compensation increment as a basic compensation constant, and performing superposition operation on the viscosity compensation increment and a preset concentration threshold value to obtain a target concentration value.
9. The concentration feedback-based diamond wire cutting coolant proportioning control method according to claim 1, wherein the specific process of improving the physical strength of the compensation fluid lubricating film through solute concentration is as follows: And taking the corrected target concentration value as a target, increasing the output power of the stock solution replenishing pump or the duty ratio of the stock solution replenishing pump, and increasing the proportion of the stock solution in the cooling liquid circulation loop, so that the actual concentration of the cooling liquid in the circulation loop approaches to the corrected target concentration value, and compensating the physical strength of the fluid lubricating film through the increase of the solute concentration.
10. A concentration feedback-based diamond wire cutting coolant proportioning control system for executing the method of any one of the preceding claims 1-9, comprising: The viscosity library construction module is used for pre-storing target viscosity intervals under the combination of different diamond wire diameters and wire speeds, constructing a multi-station target viscosity library, wherein the target viscosity intervals comprise a lower viscosity limit value and an upper viscosity limit value, and acquiring a target viscosity interval corresponding to the current cutting process parameters; The viscosity calibration module is used for collecting a real-time viscosity value and a real-time temperature signal of the cooling liquid in the circulation loop in real time and converting the real-time viscosity value into a calibrated viscosity value at a standard temperature by utilizing a preset viscosity-temperature characteristic curve; The decay evaluation module is used for calculating the ratio of the calibrated viscosity value to the real-time concentration reading fed back by the online concentration meter to obtain a functional decay evaluation value; The failure judgment and compensation calculation module judges that the cooling liquid polymer chain is in shearing failure if the calibrated viscosity value is lower than the viscosity lower limit value and the functional decline evaluation value is lower than the decline early warning threshold value; And the concentration adjustment execution module increases the output power or the duty ratio of the stock solution supply pump according to the corrected target concentration value, improves the proportion of the stock solution in the circulation loop, and improves the physical strength of the compensation fluid lubricating film through solute concentration.

Description

Concentration feedback-based diamond wire cutting cooling liquid proportioning control method and system Technical Field The invention belongs to the technical field of diamond wire cutting, and particularly relates to a concentration feedback-based diamond wire cutting cooling liquid proportioning control method and system. Background With the extremely pursuit of cost reduction and efficiency enhancement of silicon wafers in the photovoltaic industry, the diamond wire cutting technology rapidly evolves towards the directions of extremely fine (wire diameter is less than or equal to 20 mu m) and high wire speed (wire speed is more than or equal to 40 m/s), the core function of the cooling liquid is upgraded to form a stable fluid lubrication film between the diamond wire moving at high speed and the kerf of the silicon wafers, and the performance stability of the cooling liquid directly determines the cutting precision and the quality of the silicon wafers. At present, an electric conductivity type or refractive index type concentration sensor is commonly adopted in industry to monitor and automatically control the concentration of cooling liquid on line. However, under the working condition of cutting the extremely fine wire diameter, the prior art has two main core defects: After the superfine silicon powder generated by cutting enters the cooling liquid, weak hydrolysis or complexation reaction is carried out at a specific temperature and a pH value, silicate ions are released, and the ion composition of the cooling liquid is changed. The conductivity type sensor can only detect the overall conductivity, cannot distinguish the additional ionic conductivity generated by the reaction of the basic conductivity of the stock solution and the silicon powder, and is easy to misjudge the overall conductivity with higher concentration as too high, so that the cooling liquid is excessively supplemented with water to dilute the cooling liquid, and the lubrication performance and the cooling performance are attenuated. The high molecular polymer used for improving the lubricating performance in the cooling liquid is subjected to mechanical chain breakage under the strong shearing action of high-speed circulation, so that the dynamic viscosity is obviously reduced. The existing concentration sensor can only feed back the total solid content, cannot identify the integrity of a high molecular chain, and can generate false stability that the concentration value reaches the standard but the lubricating function is lost, the ultra-thin wire diameter diamond wire is highly sensitive to the integrity of a liquid film, and the defect of insufficient viscosity can easily cause the occurrence of burn-out wire, broken wire or exceeding of TTV of a silicon wafer. In summary, the existing control method based on concentration feedback cannot eliminate the interference of silicon powder hydrolysis on concentration detection, cannot sense the functional decline of the cooling liquid caused by polymer chain breakage, and is difficult to meet the dual requirements of superfine wire diameter cutting on fluid dynamics performance and concentration detection precision, so that a technical scheme for controlling the cooling liquid capable of accurately distinguishing conductivity sources and sensing the decline of lubricating function is needed. Therefore, the invention provides a concentration feedback-based diamond wire cutting cooling liquid proportioning control method and a concentration feedback-based diamond wire cutting cooling liquid proportioning control system. Disclosure of Invention In order to overcome the deficiencies of the prior art, at least one technical problem presented in the background art is solved. The technical scheme adopted for solving the technical problems is as follows: in one aspect, the invention provides a concentration feedback-based diamond wire cutting cooling liquid proportioning control method, which comprises the following steps: s10, pre-storing target viscosity intervals under the combination of different diamond wire diameters and wire speeds, constructing a multi-station target viscosity library, wherein the target viscosity intervals comprise a lower viscosity limit value and an upper viscosity limit value, and acquiring a target viscosity interval corresponding to the current cutting process parameters; s20, collecting a real-time viscosity value and a real-time temperature signal of the cooling liquid in the circulation loop in real time, and converting the real-time viscosity value into a calibrated viscosity value at a standard temperature by utilizing a preset viscosity-temperature characteristic curve; Step S30, calculating the ratio of the calibrated viscosity value to the real-time concentration reading fed back by the online concentration meter to obtain a functional decline evaluation value; Step S40, judging that the cooling liquid polymer chain is in shear failure if the calibrate