Focused photolithography tuning fork wafer and its preparation process

Abstract

The present invention relates to the field of tuning fork wafer manufacturing technology, and in particular to the intersection of semiconductor manufacturing technology and precision machining technology. The present invention provides a focused photolithography tuning fork wafer and its preparation process, which includes raw material preparation, wafer loading, shape etching, coating treatment, vibration arm groove processing, electrode pattern production, frequency fine-tuning, wafer separation, quality control and traceability. Its core innovation lies in the use of improved laser processing equipment, which has a dual-station motion platform, a precisely adjustable laser generator and a high-precision acquisition camera. This design realizes parallel processing, that is, one workstation performs laser etching while the other workstation performs path scanning, which greatly improves the processing efficiency. The innovation of the process method and equipment not only significantly improves the production efficiency and quality of tuning fork wafers, but also enhances the controllability and flexibility of the manufacturing process, laying the foundation for the further development of tuning fork wafer technology.

Description

Technical Field

[0001] The present invention relates to the field of tuning fork wafer manufacturing technology, in particular to the cross-field of semiconductor manufacturing technology, precision machining technology, automated equipment manufacturing technology, and precision instrument manufacturing technology. Background Art

[0002] Tuning fork chips are an important electronic component, widely used in various electronic devices, such as mobile phones, computers, and audio equipment. Its preparation process involves multiple fields such as semiconductor manufacturing technology, automation equipment manufacturing, and precision instrument manufacturing. The structure and preparation process of tuning fork chips are relatively complex and require multiple steps, including raw material wafer preparation and pretreatment, wafer loading, shape etching, coating treatment, vibration arm and its groove processing, electrode pattern production, frequency fine-tuning, chip separation, final testing and packaging, etc.

[0003] In recent years, laser cutting technology has been widely used in some processes of tuning fork wafer production. This technology uses high-power density laser to quickly vaporize the material to form a narrow slit to complete the cutting. Compared with traditional methods, laser cutting has the advantages of fast speed, high precision and high degree of automation, making it one of the ideal processes for tuning fork wafer processing.

[0004] However, laser cutting technology still faces some challenges in the process of tuning fork wafer production. In miniaturized surface-mounted wafers, the heat interaction between adjacent cut edges may lead to a decrease in processing accuracy. There is also the groove processing link of the vibration arm: since the local area of ​​the groove processing is much larger than the cutting of the rest of the parts, it is easy to cause heat accumulation; at the same time, the groove needs to be processed symmetrically on both sides, which increases the difficulty of the process. During the processing, the local temperature may rise to 400~500℃. At such a high temperature, the thermal expansion effect of the wafer becomes significant and cannot be ignored. More importantly, this high temperature environment may cause irreversible damage to the material structure of the wafer, affecting its performance and reliability. Therefore, temperature control in groove processing becomes a key issue. At present, in order to avoid the negative effects of these thermal effects, the industry still mainly uses traditional chemical wet etching technology in the vibration arm groove processing link. Although this method has a slow processing speed, it can effectively ensure the processing quality and performance stability of the wafer, and at the same time provide development space for the improvement of laser cutting technology in the future. However, although the manufacturing techniques introduced in the patent with authorization announcement number CN100352074C solve some problems, it still does not completely overcome the thermal effect challenges faced by laser cutting technology. Although this method improves the performance by adjusting the vibration arm structure, it does not directly solve the temperature control problem in groove processing.

[0005] Secondly, during the laser cutting process, positioning accuracy directly affects the processing quality. Usually, the laser generator is installed on the Z axis and has a lifting function, while the wafer is fixed on a motion platform with X / Y translation and θ axis steering functions. Every time the wafer enters the motion platform, it needs to be initially positioned with the laser generator (usually using visual guidance technology and the movement of the motion platform). This positioning process is quite time-consuming, but it is necessary in every process.

[0006] In response to the problem of positioning accuracy, the authorization announcement number CN117393482B proposed a fully automatic wafer tuning fork laser frequency modulation device, which includes a coarse positioning mechanism and a positioning test mechanism. The device uses a multi-step positioning process, including coarse positioning photography, precise placement and precise positioning, to ultimately achieve wafer testing and frequency modulation. This method improves positioning accuracy to a certain extent, but requires two transfers for positioning, which is not efficient.

[0007] In summary, although laser cutting technology has shown great potential in the production of tuning fork wafers, it still needs to be optimized in terms of temperature control of groove processing and positioning efficiency between processes. Therefore, developing a fully automated tuning fork wafer preparation process that can effectively solve these problems will be of great significance to improving production efficiency and product quality. Summary of the invention

[0008] In view of this, the present invention provides a fully automated tuning fork wafer preparation process and dedicated equipment thereof, which realizes high-efficiency and high-precision tuning fork wafer production through innovative dual-station parallel processing, intelligent positioning algorithm and full-process parameter optimization, and significantly improves manufacturing efficiency and product quality.

[0009] The technical solution of one of the subjects of the embodiments of the present invention is implemented as follows: a fully automated tuning fork wafer preparation process comprises the following steps:

[0010] a) Raw material preparation and pretreatment, including selection of high-quality quartz wafers and ultrasonic cleaning;

[0011] b) Loading the processed wafers into the wafer box;

[0012] c) Profile etching using improved laser processing equipment, the equipment comprising:

[0013] Dual-station motion platform, with two motion platforms that can move and lock synchronously in the X, Y, and θ axes;

[0014] The laser generator installed above the dual-station motion platform can be precisely adjusted in the Z-axis direction;

[0015] Two high-precision acquisition cameras are symmetrically fixed on one side of the laser generator. The distance between the shooting focus and the beam focus point of the laser generator is consistent with the distance between the centers of the two platforms in the double-station motion platform.

[0016] d) Coating treatment;

[0017] e) Vibration arm groove processing;

[0018] f) Electrode patterning;

[0019] g) Frequency fine-tuning;

[0020] h) Wafer separation;

[0021] i) quality control and traceability;

[0022] Among them, steps c), e), f) and g) use the same workflow: one workstation performs laser etching while another workstation performs path scanning. The processed wafers are returned to the wafer box and new wafers are loaded into the vacant workstation; and only the first wafer is scanned and positioned in all directions. For subsequent wafers, the system uses the motion trajectory of the first wafer to synchronously overlap the motion trajectory in the computer to the real-time scanning status, and quickly calculates the precise X / Y translation and θ-axis rotation positioning adjustment parameters by analyzing the offset. This solution realizes fully automated tuning fork wafer preparation and improves production efficiency and accuracy. In particular, through dual-station parallel processing and intelligent positioning algorithms, the processing speed and accuracy are greatly improved.

[0023] Preferably, in step a), the ultrasonic cleaning adopts a solution of pure water and surfactant. This additional solution can effectively remove dust, oil and other tiny particles on the surface. This cleaning process can completely remove surface pollutants, avoid dust and dirt from absorbing and scattering laser power, thereby ensuring uniform distribution and accurate transmission of energy during laser cutting.

[0024] Preferably, in step c), the shape etching uses a focused infrared or ultraviolet picosecond light source, with a target etching depth of ≥150μm and a line width of 1μm to 8μm. This additional solution uses an infrared picosecond light source to achieve precise etching with a depth of ≥150μm, ensuring the dimensional accuracy and surface flatness of the tuning fork shape.

[0025] Preferably, in step d), the coating treatment adopts sputtering coating technology. The coating structure is a double-layer design: the bottom layer uses chromium or nickel as an adhesion layer; the surface layer uses precious metal materials such as gold or silver as the main conductive layer. The entire coating process lasts 15 to 30 minutes, and the specific time is adjusted according to the required coating thickness and equipment parameters. This additional solution achieves a uniform, dense and highly adhesive tuning fork chip starting electrode through a precisely controlled sputtering process. The chromium or nickel in the bottom layer provides excellent adhesion, while the precious metal in the surface layer ensures good conductivity and oxidation resistance.

[0026] Preferably, in step e), the vibrating arm groove processing adopts a galvanometer-type green light picosecond laser system, with a laser wavelength of 532nm, a pulse width of 10ps, a repetition frequency of 1MHz, an average power of 10W, a scanning speed of 1000mm / s, and a target etching depth of 40μm~100μm. This additional solution uses a green light picosecond laser system to achieve high-precision, low-heat-affected groove processing and improve tuning fork performance.

[0027] Preferably, in step f), the electrode pattern is made using a focused ultraviolet picosecond light source with a laser wavelength of 355 nm, a pulse width of 10 ps, ​​a repetition frequency of 1 MHz, and an average power of 10 W. This additional solution uses an ultraviolet picosecond light source to achieve fine electrode patterns and improve electrode quality.

[0028] Preferably, in step g), the frequency fine-tuning adopts a galvanometer-type green light picosecond laser system, with a laser wavelength of 532nm, a pulse width of 10ps, a repetition frequency of 1MHz, an average power of 10W, a measurement frequency range of 32768Hz-40000Hz, and a step of 1Hz. This additional solution uses a green light picosecond laser system to achieve precise frequency adjustment and ensure the frequency accuracy of the tuning fork.

[0029] Preferably, the material of the dual-station motion platform is marble or quartz, and a channel system is designed inside the platform for filling circulating cooling gas or liquid. This additional solution improves the temperature stability and accuracy of the processing process by using materials with good thermal stability and an active cooling system.

[0030] Preferably, the cooling system adopts closed-loop control to dynamically adjust the flow and temperature of the cooling medium according to the real-time feedback of the multi-point temperature sensors. This additional solution further improves the temperature control accuracy and ensures the processing quality through real-time temperature feedback and dynamic adjustment.

[0031] As a preferred option, it also includes the establishment of a comprehensive data management system to record the full-process production parameters, test data and environmental conditions of each batch, and implement real-time data collection and upload. This additional solution enables full-process data tracking and real-time monitoring, improving quality management and traceability.

[0032] The present invention also provides a laser processing device for preparing a tuning fork wafer, comprising:

[0033] The double-station motion platform has two identical motion platforms, which are spaced at the same plane height and can be synchronously translated and locked in the X and Y axes, and synchronously rotated and locked in the plane on the θ axis;

[0034] A laser generator is arranged above the double-station motion platform and can be precisely adjusted in the Z-axis direction;

[0035] A first high-precision acquisition camera and a second high-precision acquisition camera are symmetrically fixed on one side of the laser generator, and the distance between the shooting focus of each camera and the beam focusing point of the laser generator is consistent with the distance between the two platforms in the double-station motion platform;

[0036] A control system, used to control the laser generator to cut a wafer on a moving platform along a set path, while one of the cameras performs close-range scanning and recording of a wafer on another moving platform along the same path;

[0037] The control system is also used to use the motion trajectory of the first wafer in subsequent processing to synchronously overlap the motion trajectory with the real-time scanning status of the second wafer in the computer, and calculate the precise positioning adjustment parameters of X / Y translation and θ-axis rotation by analyzing the offset between the two. This additional solution achieves efficient parallel processing and precise positioning through a dual-station motion platform, a high-precision acquisition camera and an intelligent control system, greatly improving processing efficiency and accuracy.

[0038] Preferably, the center line of the table rotation points of the two motion platforms of the dual-station motion platform is parallel to one of the X translation axis or the Y translation axis of the dual-station motion platform. This additional solution simplifies the coordinate transformation calculation and improves the positioning accuracy and system stability by making the rotation center line parallel to the translation axis.

[0039] Compared with the existing technology, the beneficial effects of this technical solution are as follows:

[0040] The fully automated tuning fork wafer preparation process and its dedicated equipment of the present invention bring many significant advantages. First, through the innovative dual-station parallel processing technology and intelligent positioning algorithm, the production efficiency is greatly improved, and the processing accuracy is significantly improved. The high-precision acquisition camera combined with the optimized laser parameter setting ensures the high precision and stability of each processing step, thereby improving product quality and consistency.

[0041] In addition, the highly automated design not only reduces production costs, but also enhances production flexibility, enabling the system to quickly adapt to different product requirements. The innovative motion platform design and cooling system improve temperature control capabilities and further ensure processing quality. The introduction of a comprehensive data management system enhances the traceability of the production process, facilitating quality control and process optimization.

[0042] Overall, this innovative process and equipment has achieved a comprehensive breakthrough in improving production efficiency, product quality and manufacturing flexibility, injecting new impetus into the development of the tuning fork wafer manufacturing industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0044] Figure 1 This is a schematic diagram of the structure of the wafer after all etching is completed, showing the arrangement of the tuning fork chips on the wafer and their appearance after etching;

[0045] Figure 2 It is a structural schematic diagram of the improved part of the improved laser processing equipment 100, including the layout of the double-station motion platform 110, the laser generator 120, the first high-precision acquisition camera 130 and the second high-precision acquisition camera 140;

[0046] Figure 3 The numerical analysis diagram for the offset of the laser etching trajectory in the computer and the wafer overlap shows how to use the trajectory of the first wafer to accurately position the subsequent wafers;

[0047] Figure 4 for Figure 3 The enlarged image at A in the middle shows the slight deviation between the motion trajectory and the actual wafer edge;

[0048] Figure 5 A three-dimensional image of a single tuning fork wafer, showing the three-dimensional structure of the finished tuning fork wafer, including the shape, vibration arm grooves, and electrode patterns;

[0049] Figure 6 This is a flowchart of the process, which shows in detail all the process steps from raw material preparation to finished chip separation, including key links such as shape etching, coating treatment, vibration arm groove processing, electrode pattern production and frequency fine-tuning.

[0050] Reference numerals: wafer 01 , shape 011 , groove 012 , electrode pattern 013 , wafer box 02 , loading area 03 , robot arm, improved laser processing equipment 100 , double-station motion platform 110 , laser generator 120 , first high-precision acquisition camera 130 , second high-precision acquisition camera 140 . DETAILED DESCRIPTION

[0051] In the following, only some exemplary embodiments are briefly described. As those skilled in the art will appreciate, the described embodiments may be modified in various ways without departing from the spirit or scope of the present invention. Therefore, the drawings and descriptions are considered to be exemplary and non-restrictive in nature.

[0052] Below are all the attached Figure 1-6 Embodiments of the present invention are described in detail.

[0053] This embodiment provides a fully automated tuning fork wafer preparation process, which integrates advanced laser processing technology, precision positioning system and intelligent control algorithm, and realizes the automation of the whole process from raw material processing to finished product separation. Its core innovation lies in the use of a dual-station parallel processing process, combined with a high-precision acquisition camera and intelligent positioning algorithm, which greatly improves the processing efficiency and accuracy.

[0054] Step 1: Raw material preparation and pretreatment.

[0055] Raw material selection: Choose high-quality quartz wafers as raw materials. Take 4-inch wafer 01 as an example. Its size can be rectangular (side length is about 100mm×76mm) or circular (diameter is about 101.6mm). The thickness of the wafer should be 150um.

[0056] Ultrasonic cleaning: Place the selected quartz wafer 01 into an ultrasonic cleaning machine. Use deionized water as the cleaning fluid to remove dust, grease and other contaminants on the surface of the wafer 01. Set the cleaning time to 15 minutes to ensure that the surface of the wafer 01 is thoroughly cleaned.

[0057] Step 2: Wafer 01 loading.

[0058] Load the processed wafers 01 one by one into the wafer box 02, which is a carrier with multiple spaced slots. Use a wafer positioner to ensure that each wafer is in the same position in the slot. After loading, cover the lid of the wafer box 02 and label it with relevant information. Install the wafer box 02 to the loading area 03 of the automated equipment to ensure that it is correctly docked with the equipment. Perform a system self-check to ensure that the loading mechanism and sensors are working properly. Finally, start the automatic loading program through the control system, monitor the entire loading process, and ensure that the wafers are smoothly and orderly transferred to the subsequent processing equipment.

[0059] Step 3: Etching of the outer shape 011.

[0060] The improved laser processing device 100 is used for profile etching. The device is structurally optimized to improve the temperature control capability and overall positioning efficiency of groove processing. The main improvements include:

[0061] 1. Dual-station motion platform 110: It has two identical motion platforms, which are spaced apart and arranged at the same plane height, and can be synchronously translated and locked in the X and Y axes, and can be synchronously rotated and locked in the plane on the θ axis. This motion platform replaces the traditional single motion platform and allows two wafers to be processed at the same time. When one wafer is laser cut, the other wafer is synchronously scanned along the cutting track.

[0062] 2. Laser generator 120: It is arranged above the dual-station motion platform 110 and can be precisely adjusted in the Z-axis direction to adapt to the selection of different light sources and the cutting of wafers of different depths and thicknesses.

[0063] 3. High-precision acquisition camera: Two high-precision acquisition cameras (a first high-precision acquisition camera 130 and a second high-precision acquisition camera 140) are symmetrically fixed on one side of the laser generator 120. The distance between the shooting focus of each camera and the beam focus point of the laser generator 120 is consistent with the distance between the two platforms in the double-station motion platform 110.

[0064] This design achieves the following purpose: when the laser generator 120 cuts the wafer on one moving platform along a set path, one of the cameras performs close-range scanning and recording of the wafer on another moving platform along the same path. Therefore, when the laser generator 120 completes the path cutting, such as the outline, the camera has completely recorded the actual state of the other wafer under the cutting path.

[0065] The advantages of this innovative design in this step include: a. Early detection: It can detect potential problems on the wafer early, such as tiny cracks, dust particles or other defects; b. Preventive maintenance: By analyzing the scanning data, it is possible to predict possible processing problems and take preventive measures; c. Quality control: Real-time monitoring of the processing process to ensure the consistency of processing quality of each wafer; d. Efficiency improvement: Through parallel processing and early detection, the overall processing efficiency is significantly improved; e. Reduce scrap rate: By detecting and handling problems at an early stage, the scrap rate caused by processing defects can be greatly reduced.

[0066] What's more, this innovative design significantly improves positioning efficiency and accuracy in the back-end process, that is, when the wafer returns to the motion platform for further processing after other processes that require it to leave the motion platform (such as coating). Since the wafer will inevitably produce position deviations in the process of leaving and returning to the motion platform, the traditional method requires re-scanning and positioning each wafer in all directions, which is time-consuming and prone to cumulative errors. This innovative design can quickly and accurately compensate for these position deviations through intelligent algorithms and high-precision scanning, greatly improving the efficiency and accuracy of subsequent processing.

[0067] The specific improvement method is: only the first wafer needs to be scanned and positioned in all directions. For the second wafer, the system uses the motion trajectory of the first wafer and synchronously overlaps the motion trajectory in the computer with the real-time scanning status of the second wafer, that is, the existing shape cutting path. Figure 3 The system can quickly calculate the precise X / Y translation and θ axis rotation positioning adjustment parameters by analyzing the offset between the two and using advanced algorithms. Since there are many numerical points that can be compared between the motion trajectory and the existing contour cutting path, the algorithm can achieve very accurate calculation results.

[0068] The advantages of this method are particularly evident in the processing of circular wafers. Because the circle has symmetry in any plane rotation, the traditional positioning method is more time-consuming when processing circular wafers. The new method can quickly and accurately determine the positioning of the completed circular wafer by utilizing the data of synchronous real-time scanning.

[0069] This innovative positioning method not only improves the efficiency and accuracy of profile etching, but also brings significant time and cost savings to the entire tuning fork wafer manufacturing process, while improving the consistency of product quality. This method is particularly advantageous when processing materials with strong symmetry such as round wafers.

[0070] Continue with the process of etching the outer shape 011 in step three:

[0071] S1. Initial preparation: The laser generator 120 rises to a safe height in the Z-axis direction and is away from the dual-station motion platform 110. The robot arm takes out two wafers 01 from the wafer box 02 in the loading area 03 in sequence and places them on two working positions of the dual-station motion platform 110 of the laser processing equipment 100 respectively.

[0072] S2. Wafer positioning: By controlling the precise movement of the dual-station motion platform 110, the precise position of the wafer 01 to be laser etched is adjusted.

[0073] S3 laser parameter setting: The laser generator 120 uses a focused infrared picosecond light source. Set the optimization parameters: laser wavelength, pulse width, repetition frequency and average power. Target etching depth: ≥150 um.

[0074] S4 etching process: The laser generator 120 descends to the preset working height. At the same time, the first high-precision acquisition camera 130 or the second high-precision acquisition camera 140 (depending on the working position) has synchronously come to the top of the wafer 01 to be scanned. The laser generator 120 is started according to the preset program to etch the outline of all tuning fork crystals on the wafer 01. The acquisition camera also synchronously completes the path scanning of the corresponding wafer 01.

[0075] S5 Post-etching processing: After etching and scanning are completed, the laser generator 120 rises to a safe height. The robot arm returns the processed wafer 01 to the wafer box 02. For the wafer 01 that has completed scanning and is qualified, the system calculates its precise positioning coordinates through image analysis and algorithms.

[0076] S6 cycle processing: The dual-station motion platform 110 moves precisely into position according to the previously recorded coordinate values. The robot arm places the new wafer 01 into the vacant workstation. The laser generator 120 descends to the working height again. The system executes the above steps in a cycle: a) One workstation performs laser etching. b) At the same time, another workstation performs path scanning. c) The processed wafer returns to the wafer box, and the new wafer is loaded into the vacant workstation.

[0077] S7 continuous production: This process is continuously cycled to ensure the continuity and efficiency of production.

[0078] Step 4: Coating treatment.

[0079] The wafer box 02 containing the tuning fork wafer with the contour cut completed is transferred to the vacuum coating chamber. Argon is filled into the coating chamber as the working gas, the working pressure is maintained at 0.5Pa, and the working temperature is set to 200℃. Sputtering coating technology is used to form a uniform metal layer on the surface of the wafer. Gold is selected as the coating material. The entire coating process lasts 20 minutes. After the coating is completed, a high-precision optical microscope is used to test the thickness and uniformity of the coating to ensure that it meets the specification requirements. After passing the test, the wafer box 02 is returned to the loading area 03 of the laser processing equipment to prepare for subsequent processing. The environmental parameters and process indicators are strictly controlled throughout the coating process to ensure the consistency and reliability of the coating quality.

[0080] Step 5: Processing of the vibration arm groove 012.

[0081] The wafers processed in step 4 are returned to the wafer box 02, and the wafer box 02 is installed in the loading area 03 of the automation equipment. This step follows the workflow of step 3: one workstation performs laser etching while another workstation performs path scanning, the processed wafers are returned to the wafer box, and new wafers are loaded into the vacant workstation.

[0082] The advantage of this step is that, as mentioned in step 3, "only the first wafer needs to be scanned and positioned in all directions. For the second wafer, the system uses the motion trajectory of the first wafer and synchronously overlaps the motion trajectory in the computer with the real-time scanning status of the second wafer, that is, the existing shape cutting path. Figure 3 , the system analyzes the offset between the two and uses advanced algorithms to quickly calculate the precise positioning adjustment parameters of X / Y translation and θ axis rotation. Since there are many numerical points that can be compared between the motion trajectory and the existing contour cutting path, the algorithm can achieve very accurate calculation results. "

[0083] The difference lies in the laser parameter settings. This step uses a galvanometer-type green light picosecond laser system, and its main parameter settings are as follows: laser wavelength 532nm, pulse width 10ps, repetition frequency 1MHz, average power 10W. An important advantage of using picosecond lasers is their ultra-short pulse characteristics, which can achieve a "cold processing" effect. This light source produces a very small heat-affected zone on the material surface, and heat accumulates slowly, effectively avoiding material deformation and microstructural changes caused by thermal effects, thereby ensuring processing accuracy and product quality.

[0084] With the galvanometer scanning system, the scanning speed is set to 1000mm / s to accurately etch the grooves on the two vibrating arms on one side. The processing process first removes the metal layer and then etches the wafer. The target etching depth is 50 um and the single-sided etching time is about 5 minutes. The integrated optical detection system verifies the depth and shape of the groove in real time to ensure processing accuracy. In order to further utilize the low thermal effect advantage of picosecond laser, a multiple scanning and low energy density processing strategy can be adopted to further reduce heat accumulation and improve processing quality.

[0085] At the same time, a temperature monitoring system is introduced to track the temperature changes on the workpiece surface in real time to ensure that the temperature is always kept within a safe range. An adaptive cooling system is set up to adjust the cooling intensity in a timely manner according to temperature feedback to maintain a constant working environment.

[0086] After all wafers in a wafer box have completed the groove 012 processing on one side, repeat the groove 012 processing steps to perform the groove 012 processing on the other side. Between the two-side processing, set an appropriate cooling time to make full use of the low heat accumulation characteristics of the picosecond laser to ensure that the wafer temperature is completely restored to the initial state, so as to ensure the consistency and accuracy of the two-side processing.

[0087] Step 6: Making electrode pattern 013.

[0088] Similarly, this step continues the workflow of step three: one workstation performs laser etching while another workstation performs path scanning, the processed wafers are returned to the wafer box, and new wafers are loaded into the vacant workstation.

[0089] Similarly, the advantage brought by this step is that "only the first wafer needs to be scanned and positioned in all directions. For the second wafer, the system uses the motion trajectory of the first wafer and synchronously overlaps the motion trajectory in the computer with the real-time scanning status of the second wafer, that is, the existing shape cutting path. Figure 3 , the system analyzes the offset between the two and uses advanced algorithms to quickly calculate the precise positioning adjustment parameters of X / Y translation and θ axis rotation. Since there are many numerical points that can be compared between the motion trajectory and the existing contour cutting path, the algorithm can achieve very accurate calculation results. "

[0090] The difference lies in the laser parameter settings: this step uses a focused ultraviolet picosecond light source, the laser wavelength is precisely adjusted to 355nm, the pulse width is controlled at 10ps, the repetition frequency is set to 1MHz, and the average power is maintained at 10W. According to the pre-designed electrode model, the system accurately controls the electrode spot spacing and accurately presents the electrode pattern through high-precision laser etching technology. Throughout the process, a high-resolution camera monitors the etching quality in real time to ensure that the processing error is controlled within 10um.

[0091] Step 7: Frequency fine-tuning.

[0092] Similarly, this step continues the workflow of step three: one workstation performs laser etching while another workstation performs path scanning, the processed wafers are returned to the wafer box, and new wafers are loaded into the vacant workstation.

[0093] Similarly, the advantage brought by this step is that "only the first wafer needs to be scanned and positioned in all directions. For the second wafer, the system uses the motion trajectory of the first wafer and synchronously overlaps the motion trajectory in the computer with the real-time scanning status of the second wafer, that is, the existing shape cutting path. Figure 3 , the system analyzes the offset between the two and uses advanced algorithms to quickly calculate the precise positioning adjustment parameters of X / Y translation and θ axis rotation. Since there are many numerical points that can be compared between the motion trajectory and the existing contour cutting path, the algorithm can achieve very accurate calculation results. "

[0094] The difference is that this step uses a galvanometer-type green light picosecond laser system, and the parameters are set as follows: laser wavelength 532nm, pulse width 10ps, repetition frequency 1MHz, average power 10W. Start the integrated frequency measurement system and set the measurement frequency range to 32768Hz-40000Hz, with a step of 1Hz. The system gradually fine-tunes the etching and measures the frequency change synchronously. According to real-time feedback, the laser parameters (such as power, scanning speed, pulse repetition rate, etc.) are automatically adjusted until the target frequency is reached. To ensure etching accuracy and consistency, a temperature control system is set to maintain a constant working environment. An online quality monitoring system is introduced to analyze the frequency change trend in real time and predict the optimal etching termination point. An autofocus mechanism is added to compensate for possible changes in the height of the wafer surface. A safety interlock device is set to automatically stop the laser output under abnormal conditions. Finally, the processing parameters and frequency change curves of each wafer are recorded for subsequent analysis and process optimization.

[0095] Step 8: Chip separation.

[0096] Transfer the wafer box 02 containing the etched tuning fork wafer to the wafer folding machine. Set up a constant temperature and humidity environment, keep the temperature at 25±0.5℃, and control the humidity at 50±2%RH. Use a high-precision visual positioning system to accurately align according to the etched contour. Use low-stress folding to ensure the stability of the wafer during the separation process. Set up an automatic sorting system to store qualified and unqualified products separately.

[0097] Step 9: Quality control and traceability.

[0098] Establish a comprehensive data management system to record the full-process production parameters, test data and environmental conditions of each batch. Implement real-time data collection and upload to ensure the timeliness and accuracy of information. Introduce automated testing equipment, such as atomic force microscopes and high-precision frequency meters, to improve detection efficiency and accuracy. Establish a product life cycle traceability system to assign a unique ID to each wafer and associate its complete production history, raw material batches, equipment usage records and other information. Implement big data analysis to identify potential quality issues and optimization opportunities. Establish a customer feedback mechanism to incorporate market information into the quality improvement cycle. Conduct regular internal audits and external certifications to ensure the effectiveness and continuous improvement of the quality management system.

[0099] In some embodiments, in order to further optimize temperature control, in step 5, the material of the motion platform is selected from marble or quartz. Both marble and quartz have excellent thermal stability and low thermal expansion coefficient, which can effectively reduce the impact of ambient temperature changes on processing accuracy. At the same time, a channel system is designed inside the platform for filling circulating cooling gas or liquid. This active cooling system can accurately adjust the platform temperature to ensure that the working area is always kept within the ideal temperature range.

[0100] The cooling system uses closed-loop control to dynamically adjust the flow and temperature of the cooling medium based on real-time feedback from multi-point temperature sensors. The optional cooling medium includes temperature-controlled nitrogen or deionized water, and the specific choice depends on the process requirements and environmental conditions. In addition, the dehumidification function is integrated in the cooling system to prevent possible condensation problems and ensure the dryness of the processing environment.

[0101] In some embodiments, in order to further optimize the reading and control of the coordinate position, in step 3, the center line connecting the table rotation points of the two motion platforms of the dual-station motion platform 110 is parallel to one of the X translation axis or the Y translation axis of the dual-station motion platform 110. This design has the following advantages:

[0102] Simplified coordinate transformation: When the line connecting the rotation centers of the two platforms is parallel to a translation axis, the computational complexity of the coordinate system transformation can be greatly simplified. This enables the system to perform coordinate transformations more quickly and accurately, especially in position correction after a rotation operation.

[0103] Improved positioning accuracy: By aligning the center of rotation with the translation axis, the cumulative error caused by rotation can be reduced, thereby improving the overall positioning accuracy.

[0104] Ease of Synchronous Control: This configuration makes the synchronized motion of two stages easier to control and predict, especially in complex motions that require coordinated X / Y translation and theta rotation.

[0105] Improved system stability: By reducing unnecessary degrees of freedom and motion complexity, this design can improve the mechanical stability and reliability of the entire system.

[0106] Ease of calibration and maintenance: When the center of rotation is aligned with the translation axis, calibration and routine maintenance of the system becomes simpler and more intuitive, helping to maintain long-term machining accuracy.

[0107] This design not only optimizes coordinate control, but also improves the efficiency, precision and reliability of the entire processing system, providing a solid hardware foundation for the manufacture of high-quality tuning fork wafers.

[0108] Focused photolithography tuning fork wafer embodiment

[0109] This embodiment provides a focused lithography tuning fork wafer, referring to Figure 5 The manufacturing process is based on the fully automated tuning fork wafer preparation process described in the above embodiment, but specific optimization is performed on key steps to meet the needs of high-precision focused lithography.

[0110] Key Features

[0111] Material: X0~+5 degree cut wafer, thickness is 0.07~0.15mm.

[0112] Graphic design: Design the precise tuning fork structure, including the shape, vibrating arm and electrode pattern, using CAD software.

[0113] Electrode fabrication: Magnetron sputtering technology was used to form a chromium (5nm) / gold (100nm) double-layer structure.

[0114] Frequency adjustment: Femtosecond laser system is used for precise frequency fine-tuning, with an adjustment accuracy of up to 50nm per step.

[0115] Performance indicators: operating frequency: 32.768KHz+ / -20ppm, impedance less than 70 kilohms.

[0116] Frequency stability: better than 10ppb / day

[0117] Application areas: high-precision time standard, high-sensitivity sensor, quantum metrology, etc.

[0118] The manufacturing process of the focused lithography tuning fork wafer uses the dual-station parallel processing and intelligent positioning algorithm in the above embodiment, while introducing higher-precision process control in key steps. This optimization enables the product to achieve higher precision and performance while maintaining high-efficiency production, and is particularly suitable for scientific research and industrial applications that require extremely high precision.

[0119] Although the present disclosure has been described in detail in conjunction with only a limited number of embodiments, it should be readily understood that the present disclosure is not limited to these disclosed embodiments. Rather, the present disclosure may be modified to incorporate any number of variations, alterations, substitutions, combinations, sub-combinations, or equivalent arrangements not previously described but commensurate with the scope of the present disclosure. Additionally, although various embodiments of the present disclosure have been described, it should be understood that various aspects of the present disclosure may include only some of the described embodiments.

[0120] Accordingly, the disclosure is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims.

Claims

1. A tuning fork wafer preparation process, characterized in that: The following steps are involved: a) Raw material preparation and pretreatment, including selection of high-quality quartz wafers, ultrasonic cleaning and plasma treatment; b) loading the processed wafers into the wafer box; c) Profile etching using improved laser processing equipment, the equipment comprising: Dual-station motion platform, with two motion platforms that can move and lock synchronously in the X, Y, and θ axes; The laser generator installed above the dual-station motion platform can be precisely adjusted in the Z-axis direction; Two high-precision acquisition cameras are symmetrically fixed on one side of the laser generator. The distance between the shooting focus and the beam focus point of the laser generator is consistent with the distance between the two platforms in the double-station motion platform. d) Coating treatment; e) Vibration arm groove processing; f) electrode patterning; g) Frequency fine-tuning; h) wafer separation; i) quality control and traceability; Among them, steps e), f) and g) adopt the same workflow: one workstation performs laser etching while another workstation performs path scanning. The processed wafers are returned to the wafer box and new wafers are loaded into the vacant workstation; and only the first wafer is subjected to all-round scanning and positioning. For subsequent wafers, the system uses the motion trajectory of the first wafer to synchronously overlap the motion trajectory in the computer to the real-time scanning status, and quickly calculates the precise X / Y translation and θ-axis rotation positioning adjustment parameters by analyzing the offset.

2. The tuning fork wafer preparation process according to claim 1, characterized in that: In the step a), the working gas for plasma treatment is argon, the working pressure is 0.5 Pa, the working temperature is 200° C., and the treatment time is 30 minutes.

3. The tuning fork wafer preparation process according to claim 1, characterized in that: In the step c), the profile etching uses a focused infrared picosecond light source, and the target etching depth is ≥0.15 mm.

4. The tuning fork wafer preparation process according to claim 1, characterized in that: In the step d), the coating process adopts the sputtering coating technology, the coating material is chromium plus gold, and the coating process lasts for 30 minutes.

5. The tuning fork wafer preparation process according to claim 1, characterized in that: In the step e), the vibration arm groove is processed using a galvanometer-type green light picosecond laser system with a laser wavelength of 532nm, a pulse width of 10ps, a repetition frequency of 1MHz, an average power of 10W, a scanning speed of 1000mm / s, and a target etching depth of 0.01-0.05mm.

6. The tuning fork wafer preparation process according to claim 1, characterized in that: In the step f), the electrode pattern is produced using a focused ultraviolet picosecond light source with a laser wavelength of 355 nm, a pulse width of 10 ps, ​​a repetition frequency of 1 MHz, an average power of 10 W, and an electrode line width and spacing of 0.05 mm.

7. The tuning fork wafer preparation process according to claim 1, characterized in that: In the step g), the frequency is fine-tuned using a galvanometer-type green light picosecond laser system with a laser wavelength of 532nm, a pulse width of 10ps, a repetition frequency of 1MHz, an average power of 10W, a measurement frequency range of 32768Hz-40000Hz, and a step of 1Hz.

8. The tuning fork wafer preparation process according to claim 1, characterized in that: The material of the double-station motion platform is marble or quartz, and a channel system is designed inside the platform for filling circulating cooling gas or liquid.

9. The tuning fork wafer preparation process according to claim 8, characterized in that: The duct system adopts closed-loop control to dynamically adjust the flow and temperature of the cooling medium according to real-time feedback from multi-point temperature sensors.

10. The tuning fork wafer preparation process according to claim 1, characterized in that: It also includes establishing a comprehensive data management system to record the full-process production parameters, test data and environmental conditions of each batch, and implement real-time data collection and uploading.

11. A laser processing device for preparing a tuning fork wafer, characterized in that: include: The double-station motion platform has two identical motion platforms, which are spaced at the same plane height and can be synchronously translated and locked in the X and Y axes, and synchronously rotated and locked in the plane on the θ axis; A laser generator is arranged above the double-station motion platform and can be precisely adjusted in the Z-axis direction; A first high-precision acquisition camera and a second high-precision acquisition camera are symmetrically fixed on one side of the laser generator, and the distance between the shooting focus of each camera and the beam focusing point of the laser generator is consistent with the distance between the two platforms in the double-station motion platform; A control system, used to control the laser generator to cut a wafer on a moving platform along a set path, while one of the cameras performs close-range scanning and recording of a wafer on another moving platform along the same path; The control system is also used to utilize the motion trajectory of the first wafer in subsequent processing to synchronously overlap the motion trajectory with the real-time scanning status of the second wafer in the computer, and calculate the precise X / Y translation and θ-axis rotation positioning adjustment parameters by analyzing the offset between the two.

12. The laser processing equipment for preparing tuning fork wafer according to claim 11, characterized in that: The center line connecting the table rotation points of the two motion platforms of the double-station motion platform is parallel to one of the X translation axis or the Y translation axis of the double-station motion platform.

13. A focusing photolithography tuning fork wafer, characterized in that: The tuning fork wafer is manufactured by the tuning fork wafer preparation process described in any one of claims 1 to 10, and has the following characteristics: a ) Using high-purity, low-defect quartz wafers with a thickness of 80~150μm as raw materials; b) The electrode is made by magnetron sputtering technology to form a double-layer structure of chromium and gold; c) The frequency fine-tuning adopts a femtosecond laser system, and the adjustment accuracy can reach 5~50nm per step; d) The operating frequency is 32.768KHz, the impedance is less than 70 kilo-ohms, and the frequency stability is better than 10ppb / day.

14. The focusing photolithography tuning fork wafer according to claim 13, characterized in that: In b), the electrode is made by magnetron sputtering technology to form a chromium and silver double-layer structure.

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