Full-system cooling device and method for multi-wire cutting of silicon carbide wafer

Abstract

The invention provides a full-system cooling device and method for multi-wire cutting of silicon carbide wafers. A full-system cooling network of motor water cooling, cooling liquid purification, constant temperature of an electric appliance cabinet and compressor cooling is adopted; a motor adopts a double-path cooling design with flow control of a main shaft water-cooling shaft, cooling liquid is integrated with a multi-stage filtering and constant temperature module, an electric appliance cabinet is additionally provided with a precise air conditioner, and a compressor is provided with a special water-cooled jacket; meanwhile, the wire body state is monitored in real time through stress sensors at the two ends of the take-up and pay-off wheel, and a roller microgroove restrains the diamond wire track. The device solves the problems that in traditional cutting, a wire body is prone to snap, cooling is uneven, and the service life of equipment is short, the snap rate of the diamond wire is reduced by 85%, the cutting precision of 12-inch and 8-inch wafers reaches + / -4 microns, the motor power attenuation rate is smaller than 5%, the equipment maintenance cost is reduced by 40%, and the device is suitable for mass production scenes of large-size silicon carbide wafers and has remarkable technical and economic values.

Description

Technical Field

[0001] This invention relates to the field of silicon carbide wafer processing technology, specifically to a complete cooling device and method for multi-wire cutting of silicon carbide wafers, which is particularly suitable for high-efficiency and high-precision cutting of large-size silicon carbide wafers. Background Technology

[0002] Silicon carbide, as a core material for third-generation semiconductors, boasts a high melting point of 3480℃, a hardness of HV2800, and excellent high-temperature breakdown resistance, making it an essential material in high-end manufacturing fields such as power modules for new energy vehicles, RF devices for 5G base stations, and high-temperature resistant components for aerospace. Multi-wire dicing, a crucial processing step in the silicon carbide wafer transformation from ingot to substrate, requires achieving ultra-thin dicing precision of 600-800μm for 12-inch and 8-inch large-size wafers. It also necessitates ensuring low loss of four-layer square micro-powder diamond wire with a diameter of 0.37-0.45mm and continuous, stable 24-hour operation of the equipment. The overall system cooling efficiency directly determines dicing precision, equipment uptime, and production cost control, making it a core technological pillar for overcoming the bottleneck of large-size wafer mass production.

[0003] In the silicon carbide multi-wire cutting process, the heat dissipation requirements of core components such as motors, electrical cabinets, coolants, and compressors exhibit characteristics of "high load and strong correlation": the motor drives the take-up and untake-up reels and rollers to achieve a linear speed of 1800-2000 m / min, and the frictional heat power generated by the high-speed rotation of the spindle can reach more than 5kW; the grinding action of the diamond wire and the wafer causes the instantaneous temperature of the cutting area to rise to more than 150℃, requiring the coolant to continuously remove the heat; the electrical cabinet integrates precision electronic components such as PLC control systems and servo drives, with a heat dissipation density per unit volume exceeding 100W / dm. 3 The compressor provides power to the cooling system, and its exhaust temperature can reach over 85℃ during operation. Cooling failure in any part of the system can trigger a chain reaction: motor overheating leads to power output fluctuations, and a linear speed deviation of ±50m / min causes sudden changes in diamond wire tension; coolant temperature imbalance exacerbates wire wear, and impurity accumulation causes scratches on the cutting surface; high temperatures in the electrical cabinet cause control signal delays, resulting in delayed response to wire breakage braking; insufficient compressor cooling shortens equipment lifespan, creating a vicious cycle of "cooling failure - process fluctuations - downtime."

[0004] However, the cooling systems of existing silicon carbide wafer multi-wire dicing equipment suffer from three major defects: isolated design, crude control, and lack of coordination, which are far from meeting the demands of high-precision mass production. Regarding motor cooling, traditional equipment uses only a single-layer peripheral water-cooling jacket with a gap of >2mm between the jacket and the motor housing. The cooling channel has a straight cylindrical structure, preventing the rapid dissipation of heat from the spindle. After long-term operation, the spindle temperature rises above 60℃, and the motor power attenuation rate reaches as high as 15%. This not only leads to unstable line speed but also causes instantaneous changes in diamond wire tension exceeding ±20N, increasing the wire breakage probability to 5 times per thousand hours. A single wire breakage requires a shutdown of more than 30 minutes to replace the wire, reducing equipment uptime to below 80%.

[0005] The shortcomings of the coolant cooling and filtration system are even more prominent: existing equipment mostly adopts a "single-stage coarse filtration + natural heat dissipation" mode, with a filtration accuracy of only 50μm, which cannot intercept micron-sized abrasive impurities generated during cutting. These impurities repeatedly scratch the wafer surface with the coolant circulation, resulting in a surface roughness Ra > 0.5μm; and there is a lack of constant temperature control module, with the temperature in the cutting area fluctuating by more than ±5℃ with the processing time. The thickness deviation of silicon carbide wafers due to thermal expansion and contraction exceeds ±10μm, and the yield of 12-inch wafers is less than 70%. Although some equipment is equipped with simple cooling devices, the coolant flow rate is not linked to the cutting load. The thermal load for cutting 8-inch and 12-inch wafers differs by 30%, but the same cooling parameters are used, resulting in a 30% waste of energy in cutting small-size wafers and insufficient cooling for cutting large-size wafers, causing edge chipping.

[0006] The cooling and protection of electrical cabinets and compressors have long been neglected: As the "brain" of the equipment, traditional designs of electrical cabinets rely solely on natural ventilation, lacking precision air conditioning and anti-corrosion filtration devices. In coastal high-salt-spray environments, salt spray particles entering the cabinet increase circuit board corrosion rates by five times. In high-temperature and high-humidity environments, electronic component failure rates are more than three times higher than in normal-temperature environments. A single repair requires disassembling the cabinet and replacing components, taking over two hours and severely impacting production continuity. As the "power source" of the cooling system, existing equipment lacks dedicated cooling jackets, relying solely on natural air cooling. Operating at temperatures above 85℃ for extended periods accelerates the aging of internal rubber seals, shortening their lifespan to 800 hours, only 50% of the designed lifespan. Furthermore, the risk of refrigerant leakage increases to 10% per year. Leaks not only pollute the environment but also necessitate production shutdowns for refrigerant replacement, resulting in tens of thousands of yuan in economic losses.

[0007] More critically, the existing cooling system is completely disconnected from the line control and process parameters, creating a "lone wolf" technical pain point. When insufficient motor cooling causes power fluctuations, although the stress sensor can detect sudden changes in diamond wire tension, the cooling system cannot automatically respond and adjust the flow rate, requiring manual valve adjustment with a response lag of more than 1 minute, during which time the line may have already deviated or derailed. When coolant temperature imbalance leads to increased cutting resistance, although the roller anti-derailment structure can provide some restraint, the cooling system is not linked to the oscillating cutting parameters and cannot reduce frictional heat by adjusting the wafer oscillation frequency (1-3 times / second), further aggravating line wear. During equipment operation, the cooling system parameters (such as flow rate and temperature) lack data correlation with line parameters (tension and linear speed) and process parameters (wafer size and thickness), failing to form a closed-loop mechanism of "heat load monitoring - adaptive adjustment of cooling parameters - line status feedback," resulting in frequent manual calibration by operators, which relies on experience and is prone to human error.

[0008] As silicon carbide wafers evolve towards larger sizes, thinner profiles, and higher precision, the technological shortcomings of traditional cooling systems are becoming increasingly apparent, posing a key bottleneck to the industrialization of third-generation semiconductors. There is an urgent need to develop a comprehensive cooling solution integrating "multi-component collaborative cooling, intelligent parameter control, and line control linkage" to overcome existing technological limitations and meet the stringent requirements of high-end silicon carbide wafer mass production. Summary of the Invention

[0009] To address the aforementioned technical shortcomings, the purpose of this invention is to provide a complete cooling device and method for multi-wire dicing of silicon carbide wafers, thereby controlling dicing trajectory deviation and improving wafer yield.

[0010] To achieve the above objectives, the present invention adopts the following technical solution:

[0011] A complete cooling system for multi-wire dicing of silicon carbide wafers, comprising:

[0012] There are two line control modules, symmetrically arranged on both sides of the silicon carbide wafer; the line control modules are used to monitor and constrain the diamond wire running status in real time.

[0013] The wafer dicing adjustment module is located above the silicon carbide wafer. It is used to control the feed of the silicon carbide wafer, drive the silicon carbide wafer to swing left and right within a certain range, and optimize the dicing mode to reduce the heat load.

[0014] A system-wide cooling module is used to achieve coordinated heat dissipation for multiple components;

[0015] The execution control module acts as the central hub of the device, handling signal processing and command execution. The line control module, wafer dicing adjustment module, and system cooling module interact and operate collaboratively through the execution control module. The line control module controls the operation of the diamond wire, the wafer dicing adjustment module controls the dicing mode of the diamond wire on the silicon carbide wafer, and the system cooling module dissipates heat.

[0016] Preferably, the wire control module includes a take-up and release reel and a roller; the take-up and release reel is mounted on a bracket; the take-up and release reel is used to retrieve and release the diamond wire; a stress sensor is installed on the bracket, and the stress sensor contacts the tangential direction of the diamond wire at a set angle to collect real-time data on the tension change of the diamond wire; the roller is a composite material roller with arc-shaped microgrooves on its surface, used to constrain the trajectory of the diamond wire to prevent it from derailing.

[0017] Preferably, the wafer dicing adjustment module includes a suspended feed structure and a wafer swaying drive assembly; the suspended feed structure is disposed above the silicon carbide wafer and is used to control the wafer feed; the wafer swaying drive assembly includes a servo motor and a transmission mechanism; the wafer swaying drive assembly is connected to the execution control module through a bus interface, and can drive the wafer to sway left and right within a certain range, reducing the continuous friction between the dicing line and the wafer.

[0018] Preferably, the system-wide cooling module includes:

[0019] The motor water cooling subsystem includes a main spindle water cooling shaft and an outer cooling sleeve; the main spindle water cooling shaft has a built-in spiral cooling channel; the outer cooling sleeve is tightly fitted to the housing of the servo motor and is equipped with a flow control unit and a temperature sensor to automatically adjust the flow rate according to the temperature of the servo motor.

[0020] The electrical cabinet air conditioning subsystem is an industrial air conditioner with integrated temperature and humidity control, used to maintain a stable temperature and humidity environment within the electrical cabinet contained in the unit, and is equipped with a high-efficiency filter.

[0021] The compressor cooling subsystem is a finned water-cooled jacket equipped with a temperature sensor, which can automatically adjust the flow rate according to the exhaust temperature of the compressor included in the unit.

[0022] The coolant filtration module includes a multi-stage filtration unit and a temperature control module. The multi-stage filtration unit is used to intercept various impurities generated during cutting, and the temperature control module is used to control the coolant temperature. It is also equipped with a high-pressure injection component to deliver the coolant to the cutting area.

[0023] Preferably, the execution control module includes a guide wheel and an audible and visual alarm unit; the guide wheel is located around the roller and is used to precisely guide the diamond wire trajectory; the audible and visual alarm unit triggers an alarm when the diamond wire tension is abnormal, and links the take-up and release wheels to perform protective actions; at the same time, the execution control module adopts a PLC controller, which is electrically connected to other components through circuits, has data storage and export functions, and has a built-in control algorithm that can dynamically adjust cooling parameters and wire parameters according to sensor feedback.

[0024] Preferably, the servo motor is connected to the execution control module via a bus interface.

[0025] Preferably, the PLC controller has data processing and instruction generation functions.

[0026] Preferably, it also includes a safety braking unit; the safety braking unit is disposed between the take-up and release reel and the guide reel, and is used to apply emergency braking to the diamond wire.

[0027] A method for using a full-system cooling device for multi-wire dicing of silicon carbide wafers includes the following steps:

[0028] S1. Device Initialization and Parameter Configuration

[0029] Input the parameters of the wafer to be cut and select the appropriate diamond wire specifications; the execution control module automatically calls the preset parameter library to generate initial operating parameters, including line speed, diamond wire tension, cooling flow rate, coolant temperature and wafer swing parameters;

[0030] S2, Preprocessing and System Startup

[0031] Manually inspect the device's operating status, replace components that have reached their service life limit, and confirm that the roller's arc-shaped microgroove is normal; start the entire system's cooling module and coolant filtration module, execute the control module to monitor the status of each key component, and after all indicators reach the preset standards, start the drive motor to enter standby mode;

[0032] S3, Line Dynamic Monitoring and Adjustment

[0033] The stress sensor collects diamond wire tension data in real time and uploads it to the execution control module. When a sudden tension change is detected that exceeds the threshold, an audible and visual warning is immediately triggered, the take-up and untake-up reels are driven to perform protective actions, and the parameters are adjusted through the wafer dicing adjustment module until the tension is restored to the set range. If a derailment signal is detected, the equipment immediately stops and locks the wafer dicing adjustment module, and at the same time issues a fault alarm.

[0034] S4, Coordinated Control of Cutting Process

[0035] The wafer dicing adjustment module drives the wafer to move and dice according to preset parameters, while the whole system cooling module continuously delivers constant-temperature filtered coolant to the dicing area; the execution control module monitors the motor temperature, compressor status and coolant quality in real time, and dynamically adjusts the parameters of each cooling subsystem based on the monitoring data; when the dicing depth reaches the set value, the wafer swaying parameters are automatically adjusted.

[0036] S5, Emergency Handling and Shutdown Completion

[0037] If a wire breakage fault is detected, the safety braking unit is immediately triggered to fix the diamond wire, and the entire system cooling module enters a pressure-holding standby state. After manual handling, historical parameters can be recalled to quickly resume operation. After cutting is completed, the equipment automatically stops running, shuts down each module in sequence, and records and stores the cutting parameters and finished product data.

[0038] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0039] 1. Significantly improved line control precision: Through the combined design of stress sensing and anti-derailment structure, instantaneous tension changes can be captured in real time, greatly reducing the wire breakage rate; physical constraints make the diamond wire derailment rate approach zero, and the cutting trajectory deviation is controlled within a high-precision range, significantly improving the wafer yield.

[0040] 2. Significantly optimized cooling efficiency across the entire system: The heat dissipation efficiency of the motor water cooling system is improved, and power attenuation is effectively controlled; the electrical cabinet protection system can effectively isolate contaminants and reduce the failure rate of circuit boards; the compressor cooling system extends equipment life and significantly reduces the risk of leakage.

[0041] 3. Reduced operational complexity and reliance on manual labor: The control unit enables automatic parameter configuration, real-time status monitoring, and automatic fault response, shortening equipment preprocessing time, eliminating the need for manual troubleshooting, and significantly reducing downtime; it also eliminates the need to rely on operator experience to adjust parameters, reducing the requirements for professional skills.

[0042] 4. Improved process adaptability and production efficiency: Through a multi-parameter collaborative adaptation mechanism, the cutting parameters of wafers of different specifications can be quickly switched, shortening the specification changeover time; the closed-loop control mechanism improves equipment utilization, increases production capacity per unit time, and significantly reduces the overall cost of large-scale production. Attached Figure Description

[0043] Figure 1 This is a schematic diagram of the structure of the present invention.

[0044] Figure 2 A schematic diagram of the structure of adding a water-cooling subsystem to a servo motor.

[0045] Figure 3 A schematic diagram of the structure for adding an electrical cabinet air conditioning subsystem to an electrical cabinet.

[0046] Figure 4 This is a schematic diagram of compressor cooling.

[0047] Figure 5 This is a schematic diagram of a coolant filtration system.

[0048] in:

[0049] 1-1. Wire take-up and take-out system; 1-2. Roller; 1-3. Safety braking unit; 2-1. Suspension feed structure; 2-2. Wafer swing drive assembly; 3-1. Motor water cooling subsystem; 3-2. Electrical cabinet air conditioning subsystem; 3-3. Compressor cooling subsystem; 3-4. Coolant filter module; 4-1. Guide wheel; 4-2. Audible and visual alarm unit. Detailed Implementation

[0050] The invention will now be further described with reference to the accompanying drawings.

[0051] like Figures 1 to 5 As shown, a complete system cooling device for multi-wire dicing of silicon carbide wafers includes a line control module, a wafer dicing adjustment module, a complete system cooling module, and an execution control module. Each module achieves data interaction and coordinated operation through the execution control module.

[0052] The wire control module is used to monitor and constrain the diamond wire's operating status in real time. It includes take-up and release reels and rollers 1-2 (anti-derailment structure). The take-up and release reels are arranged in pairs on the left and right sides of the device to realize the retrieval and release of the diamond wire. Stress sensors are installed at the rim supports of the reels. The stress sensors are in contact with the tangent direction of the diamond wire at a set angle, which can collect the diamond wire tension change data in real time. Rollers 1-2 (anti-derailment structure) are composite material rollers with arc-shaped microgrooves on the surface, which can effectively constrain the diamond wire trajectory to prevent derailment.

[0053] Wafer dicing adjustment module: used to optimize the dicing mode to reduce heat load, including a suspended feed structure 2-1 and a wafer swaying drive assembly 2-2; the suspended feed structure 2-1 is set above the material and is used to control the wafer feed; the wafer swaying drive assembly 2-2 includes a servo motor and a transmission mechanism, which is connected to the execution control module through a bus interface, and can drive the wafer to sway left and right within a certain range, reducing the continuous friction between the dicing line and the wafer.

[0054] The whole system cooling module realizes the coordinated heat dissipation of multiple components, including the motor water cooling subsystem 3-1, the electrical cabinet air conditioning subsystem 3-2, the compressor cooling subsystem 3-3, and the coolant filtration module 3-4.

[0055] The motor water cooling subsystem 3-1 includes a spindle water-cooled shaft and an outer cooling jacket. The spindle water-cooled shaft has a built-in spiral cooling channel, and the outer cooling jacket fits tightly against the motor housing. It is equipped with a flow control unit and a temperature sensor, which can automatically adjust the flow rate according to the motor temperature. The electrical cabinet air conditioning subsystem 3-2 is an industrial air conditioner with integrated temperature and humidity control, used to maintain a stable temperature and humidity environment inside the electrical cabinet, and is equipped with a high-efficiency filter. The compressor cooling subsystem 3-3 is a finned water cooling jacket, equipped with a temperature sensor, which can automatically adjust the flow rate according to the compressor exhaust temperature. The coolant filtration module 3-4 includes a multi-stage filtration unit and a constant temperature module. The multi-stage filtration unit is used to intercept various impurities generated during cutting, and the constant temperature module is used to control the coolant temperature. It is also equipped with a high-pressure injection component to deliver the coolant to the cutting area.

[0056] The execution control module, serving as the central hub of the device, handles signal processing and command execution. It includes guide wheels 4-1 and an audible and visual alarm unit 4-2. Guide wheels 4-1 are positioned around rollers 1-2 to precisely guide the diamond wire trajectory. The audible and visual alarm unit 4-2 triggers an alarm in case of abnormal conditions such as sudden changes in diamond wire tension, and coordinates with components such as the take-up and untake-down reels to perform protective actions. The execution control module employs a PLC controller, which is electrically connected to sensors and execution components of other modules via wiring. It has data storage and export functions, and a built-in control algorithm that can dynamically adjust cooling parameters and wire parameters based on sensor feedback.

[0057] Furthermore, stress sensors are installed in pairs on brackets on the rims of the take-up and pay-off reels.

[0058] Furthermore, the servo motor is connected to the execution control module via a bus interface.

[0059] Furthermore, the PLC controller has data processing and instruction generation capabilities.

[0060] The method for using a complete cooling system for multi-wire dicing of silicon carbide wafers includes the following steps:

[0061] (1) Equipment initialization and parameter configuration: Input the parameters of the wafer to be cut and select the appropriate diamond wire specification; the control unit automatically calls the preset parameter library to generate initial operating parameters, including linear speed, diamond wire tension, cooling flow rate, coolant temperature and wafer swing parameters, etc.

[0062] (2) Pre-treatment and system startup: Manually check the condition of the guide wheels, replace the guide wheels that have reached the service life, and confirm that there are no abnormalities in the roller 1-2 micro grooves; start the whole system cooling module and coolant filtration module 3-4, and the control unit monitors the status of each key part. After all indicators reach the preset standards, start the drive motor to enter the standby state.

[0063] (3) Dynamic monitoring and adjustment of the wire: The stress sensing unit collects the tension data of the diamond wire in real time and uploads it to the control unit; when a sudden change in tension is detected that exceeds the threshold, an audible and visual warning is immediately triggered, the take-up and unwinding wheels are driven to perform protective actions, and the parameters are adjusted through the tension adjustment device until the tension is restored to the set range; if a derailment signal is detected, the equipment immediately stops and locks the drive unit, and at the same time issues a fault alarm.

[0064] (4) Coordinated control of the cutting process: The wafer swing drive assembly 2-2 drives the wafer to move and cut according to the preset parameters. The high-pressure jet assembly continuously delivers the constant temperature filtered coolant to the cutting area. The control unit monitors the motor temperature, compressor status and coolant quality in real time, and dynamically adjusts the parameters of each cooling subsystem according to the monitoring data. When the cutting depth reaches the set value, the wafer swing parameters are automatically adjusted.

[0065] (5) Emergency handling and shutdown: If a wire breakage fault is detected, the safety braking unit 1-3 is immediately triggered to fix the diamond wire, and the entire system cooling module enters the pressure holding standby state; after manual handling, historical parameters can be called to quickly resume operation; after the cutting is completed, the equipment automatically stops running, shuts down each module in sequence, records the cutting parameters and finished product data and stores them.

[0066] The wafer dicing adjustment module is used to optimize the dicing mode to reduce heat load, including a suspended feed structure 2-1 and a wafer sway drive assembly 2-2; the suspended feed structure 2-1 is set above the material and is used to control the wafer feed; the wafer sway drive assembly 2-2 is used to drive the wafer to sway left and right to reduce the continuous friction between the line and the wafer.

[0067] The overall system cooling module is used to achieve coordinated heat dissipation of multiple components, including the motor water cooling subsystem 3-1, the electrical cabinet air conditioning subsystem 3-2, the compressor cooling subsystem 3-3, and the coolant filtration module 3-4; the motor water cooling subsystem 3-1 is used to cool and dissipate heat from the motor; the electrical cabinet air conditioning subsystem 3-2 is used to maintain the temperature and humidity environment inside the electrical cabinet; the compressor cooling subsystem 3-3 is used to cool the compressor; and the coolant filtration module 3-4 is used to filter and control the temperature of the coolant.

[0068] The execution control module is used to realize signal processing and command execution, including guide wheel 4-1 and audible and visual alarm unit 4-2; guide wheel 4-1 is set around roller 1-2 to guide the diamond wire trajectory; audible and visual alarm unit 4-2 is used to trigger an alarm and link related components to perform protective actions in abnormal situations.

[0069] The entire system cooling module includes a motor water cooling subsystem 3-1, an electrical cabinet air conditioning subsystem 3-2, a compressor cooling subsystem 3-3, and a coolant filtration module 3-4. The motor water cooling subsystem 3-1 uses a water-cooled shaft with a built-in spiral flow channel and a cooling jacket that fits tightly to the outside. It is connected to the cooling circulation device through pipelines, which can quickly remove the heat generated by the motor operation. The electrical cabinet air conditioning subsystem 3-2 maintains a stable temperature and humidity environment inside the cabinet and is equipped with a high-efficiency filter to block dust and impurities. The compressor cooling subsystem 3-3 expands the heat dissipation area and improves heat dissipation efficiency through a finned water cooling jacket. The coolant filtration module 3-4 intercepts impurities in a step-by-step manner in the order of coarse filtration, fine filtration, magnetic filtration, and ultrafiltration. It is equipped with a constant temperature unit to control the coolant temperature. Each subsystem is connected to the control center through a bus to achieve coordinated operation by dynamically adjusting the cooling parameters according to the equipment operating status.

[0070] Invention principle:

[0071] This invention, based on traditional multi-component heat dissipation and line control technologies, integrates intelligent closed-loop regulation, multi-field collaborative heat dissipation, and dynamic parameter adaptation design to construct a comprehensive "sensing-decision-execution-feedback" collaborative control system. This achieves dual optimization of cooling efficiency and line stability in silicon carbide wafer multi-wire dicing equipment, precisely adapting to high-precision mass production scenarios for large-size wafers. It primarily achieves dynamic control of cooling parameters by establishing real-time communication between the system's cooling module and execution control module; intelligent optimization of cooling strategies by analyzing line status and thermal load data, combined with PID algorithms and correlation models; and coordinated adjustment of multi-component heat dissipation, line tension, and dicing mode through a hierarchical heat dissipation structure and automated execution components.

[0072] I. System Cooling Principle

[0073] (I) Gradient heat dissipation adaptation principle

[0074] The thermal load characteristics of different core components vary significantly, requiring differentiated heat dissipation solutions for precise adaptation.

[0075] 1. Due to the high-speed rotation of the motor spindle, a high power density heat load is generated. A composite structure of "spiral flow channel water-cooled shaft + tightly fitting cooling jacket" is adopted. The spiral flow channel design increases the contact area between the cooling medium and the spindle, and the cooling jacket with a fitting gap of ≤1mm reduces thermal resistance, improving the heat dissipation efficiency by more than 40% compared with traditional straight-channel water cooling. It can quickly dissipate the heat generated by spindle friction and avoid power attenuation.

[0076] 2. The electrical cabinet integrates precision electronic components and needs to maintain a stable temperature and humidity environment rather than simply providing powerful heat dissipation. It adopts a precision air conditioner with dual temperature and humidity control, and uses HEPA H13 grade filters to isolate salt spray and dust. The temperature control range is 20±2℃ and the humidity is 40%-60%, which reduces the risk of electronic component failure from an environmental perspective.

[0077] 3. As the power source of the cooling system, the compressor has a high exhaust temperature and operates continuously. A finned water-cooled jacket is used to increase the heat dissipation area. The design of a fin pitch of 3 mm balances the heat transfer efficiency and fluid resistance, and can control the exhaust temperature within 80°C, delaying the aging of the seals.

[0078] (II) Principle of dynamic heat flow matching

[0079] A real-time response relationship needs to be established between the flow rate of the cooling medium and the heat load, and dynamic balance is achieved through the closed-loop linkage of temperature sensing and flow regulation: Let the temperature of the core component be T and the flow rate of the cooling medium be Q. The two satisfy the linear correlation model:

[0080] Q = k·(T - T0) + Q0

[0081] In the formula, T0 is the target temperature, Q0 is the basic flow rate, and k is the proportionality coefficient (set according to the thermal resistance characteristics of the component). When the motor temperature T > T0 (such as 45°C), the flow rate automatically increases to Q max ; when T < T0 (such as 30°C), the flow rate drops to Q min , avoiding energy waste while ensuring the heat dissipation effect, and achieving precise matching of heat flow and heat load.

[0082] (III) Principle of constant temperature purification of the coolant

[0083] Thermal deformation and impurity scratching in the cutting area are the key factors affecting the accuracy. The performance of the coolant is optimized through "multi-stage filtration + closed-loop temperature control":

[0084] 1. Designed according to the precision gradient of "50μm coarse filtration → 10μm fine filtration → magnetic filtration → 3μm ultrafiltration", abrasive particles, metal chips and colloidal impurities are intercepted in turn. After filtration, the impurity content of the coolant is ≤5 ppm, reducing scratches on the wafer surface.

[0085] 2. A semiconductor refrigeration / heating sheet is used to regulate the temperature of the coolant based on the PID algorithm, with a control accuracy of ±0.5°C. By correcting the temperature deviation in real time, the thermal deformation of the wafer caused by the temperature fluctuation of the coolant is avoided, ensuring the stability of the cutting trajectory.

[0086] II. Principle of dynamic stability control of the line body

[0087] (I) Principle of tension self-adaptive balance

[0088] The instantaneous fluctuation of the tension of the diamond wire is the main cause of wire breakage and trajectory deviation. Stable control is achieved through the closed-loop mechanism of "real-time perception - dynamic regulation":

[0089] 1. The stress sensor is in elastic contact with the diamond wire at a 30° angle, which avoids wear on the wire due to rigid contact and can capture tension fluctuations of ±0.1N. The 2Hz sampling frequency design can capture instantaneous change signals in real time.

[0090] 2. Adopting a "coarse adjustment + fine adjustment" strategy, the initial stage is coarsely adjusted according to the preset value; during the cutting process, based on sensor feedback, the tension adjustment cylinder is dynamically corrected, and the adjustment step size changes dynamically with the deviation (0.5N when the deviation is >10N, and 0.1N when the deviation is ≤10N), to ensure that the tension is stable within the set range of ±2N.

[0091] (II) Physical Trajectory Constraint Principle

[0092] As a core component for guiding the production line, the roller achieves precise trajectory constraints through structural design:

[0093] The roller's surface features arc-shaped microgrooves precisely matched to the diamond wire specifications. The radius of the groove bottom arc is equal to the wire radius, and the 0.02mm radius arc transition of the groove wall reduces wire wear. When the diamond wire experiences lateral displacement due to vibration, the lateral restraint force F generated by the groove wall... N Proportional to the offset Δx:

[0094] F N =Δx·K s

[0095] In the formula, K s To constrain stiffness (determined by the elastic modulus of the roller material), the lateral displacement of the line is restricted by a mechanical structure, so that the derailment rate approaches zero.

[0096] III. Cutting Mode Optimization and Thermal Overload Principle

[0097] To reduce heat accumulation during multi-wire dicing of silicon carbide wafers from the source and achieve a precise balance between heat load and dicing efficiency, this invention constructs a heat load suppression system through process mode innovation and dynamic parameter adaptation. Addressing the problem of concentrated heat load in the dicing area caused by continuous friction in traditional wire contact, a wafer oscillation drive component is used to periodically oscillate the wafer within a preset angle range. This transforms the contact mode between the diamond wire and the wafer from "continuous wire contact" to "intermittent point contact," reducing frictional energy input per unit time and fundamentally lowering the instantaneous temperature and heat accumulation in the dicing area. Simultaneously, a correlation model is established between "dicing depth - oscillation parameters" and "wafer size - heat load." When the dicing depth increases, the oscillation angle is automatically reduced to balance wire wear and heat load. When the wafer size changes, the oscillation frequency and cooling intensity are adapted synchronously, achieving dynamic control of heat load under different dicing conditions and effectively avoiding the impact of thermal deformation on dicing accuracy.

[0098] IV. Intelligent Closed-Loop Control and Fault Response Principles

[0099] To achieve precise control and rapid risk management throughout the multi-wire dicing process of silicon carbide wafers, this invention constructs an intelligent closed-loop system of "perception-decision-execution-feedback" and establishes a hierarchical fault response mechanism: A monitoring network is formed by sensors distributed across various modules to collect multi-dimensional data such as tension, temperature, position, and impurity content in real time. This data is then aggregated and processed by the PLC control unit. Intelligent decision-making is based on a PID algorithm and a "wafer specification-thermal load-cooling parameter" correlation model, automatically generating commands for cooling flow adjustment, tension correction, and sway parameter optimization, driving the execution components to achieve dynamic parameter adaptation and stable control. Differentiated response strategies are set for different abnormal scenarios. For minor anomalies, the algorithm automatically adjusts parameters to eliminate deviations. For moderate anomalies (such as tension exceeding a threshold), an audible and visual alarm is triggered, and the take-up and undo reels perform a protective retraction action. For severe faults (such as wire breakage or derailment), the braking unit is activated within milliseconds to clamp the wire and lock the drive system. Simultaneously, fault data is recorded and troubleshooting directions are indicated. After fault resolution, historical parameters can be directly retrieved for rapid resumption of work, minimizing downtime losses and manual intervention costs.

[0100] Implementation results:

[0101] 1. Significantly improved line control precision:

[0102] By utilizing real-time tension monitoring from stress sensors in the line control module and the physical constraints of the roller anti-derailment structure, diamond wire tension fluctuations can be accurately captured and trajectory deviations limited, effectively reducing wire breakage rates and derailment risks. Compared to traditional equipment, the frequency of diamond wire breakage is significantly reduced, cutting trajectory deviation is controlled within a high-precision range, and the yield of large-size silicon carbide wafers such as 8-inch and 12-inch wafers is significantly improved.

[0103] 2. Optimized overall system heat dissipation performance:

[0104] The entire system cooling module achieves coordinated heat dissipation of the motor, electrical cabinet, compressor, and coolant. Heat from the motor spindle is quickly discharged through the spiral flow channel, effectively suppressing power attenuation. The temperature and humidity inside the electrical cabinet are kept stable, reducing the failure rate of circuit boards in high salt spray and high dust environments. The compressor operating temperature is controllable, the aging rate of seals is slowed down, the overall heat dissipation efficiency of the equipment is improved, and the lifespan of cooling-related components is extended by more than 50%.

[0105] 3. Effective suppression of cutting heat load:

[0106] The wafer dicing adjustment module, through precise control of the suspended feed structure and dynamic oscillating motion of the oscillating drive component, changes the contact mode between the diamond wire and the wafer from continuous line contact to intermittent point contact. Combined with the constant temperature purification and precise spraying of the coolant filtration module, the heat accumulation in the dicing area is significantly reduced, and the impact of thermal deformation on dicing accuracy is minimized. The surface roughness and thickness uniformity of the wafer dicing surface are superior to those of traditional processes.

Claims

1. A complete cooling system for multi-wire dicing of silicon carbide wafers, characterized in that, include: There are two line control modules, symmetrically arranged on both sides of the silicon carbide wafer; The wire control module is used to monitor and constrain the running status of the diamond wire in real time; The wafer dicing adjustment module is located above the silicon carbide wafer. It is used to control the feed of the silicon carbide wafer, drive the silicon carbide wafer to swing left and right within a certain range, and optimize the dicing mode to reduce the heat load. A system-wide cooling module is used to achieve coordinated heat dissipation for multiple components; The execution control module acts as the central hub of the device, handling signal processing and command execution. The line control module, wafer dicing adjustment module, and system cooling module interact and operate collaboratively through the execution control module. The line control module controls the operation of the diamond wire, the wafer dicing adjustment module controls the dicing mode of the diamond wire on the silicon carbide wafer, and the system cooling module dissipates heat.

2. The complete system cooling device for multi-wire dicing of silicon carbide wafers as described in claim 1, characterized in that, The wire control module includes a take-up and release reel and a roller (1-2); the take-up and release reel is mounted on a bracket; the take-up and release reel is used to retrieve and release the diamond wire; a stress sensor is installed on the bracket, and the stress sensor contacts the tangential direction of the diamond wire at a set angle to collect the tension change data of the diamond wire in real time; the roller (1-2) is a composite material roller (1-2) with arc-shaped microgrooves processed on its surface, which is used to constrain the trajectory of the diamond wire to prevent it from derailing.

3. The complete system cooling device for multi-wire dicing of silicon carbide wafers as described in claim 1, characterized in that, The wafer dicing adjustment module includes a suspended feed structure (2-1) and a wafer swing drive assembly (2-2); the suspended feed structure (2-1) is disposed above the silicon carbide wafer and is used to control the wafer feed. The wafer swing drive assembly (2-2) includes a servo motor and a transmission mechanism. The wafer swing drive assembly (2-2) is connected to the execution control module through a bus interface, which can drive the wafer to swing left and right within a certain range, reducing the continuous friction between the production line and the wafer.

4. The complete system cooling device for multi-wire dicing of silicon carbide wafers as described in claim 3, characterized in that, The system-wide cooling module includes: The motor water cooling subsystem (3-1) includes a spindle water cooling shaft and an outer cooling sleeve; the spindle water cooling shaft has a built-in spiral cooling channel; the outer cooling sleeve is tightly fitted to the housing of the servo motor and is equipped with a flow control unit and a temperature sensor to automatically adjust the flow rate according to the temperature of the servo motor; The electrical cabinet air conditioning subsystem (3-2) is an industrial air conditioner with integrated temperature and humidity control, used to maintain a stable temperature and humidity environment inside the electrical cabinet contained in the device, and is equipped with a high-efficiency filter; The compressor cooling subsystem (3-3) is a finned water-cooled jacket equipped with a temperature sensor, which can automatically adjust the flow rate according to the exhaust temperature of the compressor included in the device; The coolant filtration module (3-4) includes a multi-stage filtration unit and a temperature control module. The multi-stage filtration unit is used to intercept various impurities generated during cutting, and the temperature control module is used to control the coolant temperature. It is also equipped with a high-pressure injection component to deliver the coolant to the cutting area.

5. The complete system cooling device for multi-wire dicing of silicon carbide wafers as described in claim 1, characterized in that, The execution control module includes a guide wheel (4-1) and an audible and visual alarm unit (4-2). The guide wheel (4-1) is located around the roller (1-2) and is used to precisely guide the diamond wire trajectory. The audible and visual alarm unit (4-2) triggers an alarm when the diamond wire tension is abnormal and links the take-up and unwinding wheels to perform protective actions. At the same time, the execution control module adopts a PLC controller, which is electrically connected to other components through circuits. It has data storage and export functions, and has a built-in control algorithm that can dynamically adjust cooling parameters and wire parameters based on sensor feedback.

6. The complete system cooling device for multi-wire dicing of silicon carbide wafers as described in claim 3, characterized in that, The servo motor is connected to the execution control module via a bus interface.

7. The complete system cooling device for multi-wire dicing of silicon carbide wafers as described in claim 5, characterized in that, The PLC controller has data processing and instruction generation functions.

8. The complete system cooling device for multi-wire dicing of silicon carbide wafers as described in claim 5, characterized in that, It also includes a safety braking unit (1-3); the safety braking unit (1-3) is located between the take-up and take-out reel and the guide reel (4-1) and is used to brake the diamond wire in an emergency.

9. A method for using a complete system cooling device for multi-wire dicing of silicon carbide wafers, characterized in that, Includes the following steps: S1. Device Initialization and Parameter Configuration Input the parameters of the wafer to be cut and select the appropriate diamond wire specifications; the execution control module automatically calls the preset parameter library to generate initial operating parameters, including line speed, diamond wire tension, cooling flow rate, coolant temperature and wafer swing parameters; S2, Preprocessing and System Startup Manually inspect the device's operating status, replace parts that have reached their service life, and confirm that the arc-shaped microgrooves of rollers (1-2) are normal; Start the entire system cooling module and coolant filtration module (3-4), execute the control module to monitor the status of each key component, and start the drive motor to enter standby mode after all indicators reach the preset standards; S3, Line Dynamic Monitoring and Adjustment The stress sensor collects diamond wire tension data in real time and uploads it to the execution control module. When a sudden tension change is detected that exceeds the threshold, an audible and visual warning is immediately triggered, the take-up and untake-up reels are driven to perform protective actions, and the parameters are adjusted through the wafer dicing adjustment module until the tension is restored to the set range. If a derailment signal is detected, the equipment immediately stops and locks the wafer dicing adjustment module, and at the same time issues a fault alarm. S4, Coordinated Control of Cutting Process The wafer dicing adjustment module drives the wafer to move and dice according to preset parameters, while the whole system cooling module continuously delivers constant-temperature filtered coolant to the dicing area; the execution control module monitors the motor temperature, compressor status and coolant quality in real time, and dynamically adjusts the parameters of each cooling subsystem based on the monitoring data; when the dicing depth reaches the set value, the wafer swaying parameters are automatically adjusted. S5, Emergency Handling and Shutdown Completion If a broken wire fault is detected, the safety braking unit (1-3) is immediately triggered to fix the diamond wire, and the entire system cooling module enters the pressure holding standby state; After manual processing, historical parameters can be recalled to quickly resume the operation; after the cutting is completed, the equipment will automatically stop running, shut down each module in sequence, record the cutting parameters and finished product data and store them.

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