Force control device for calibrating stress through micro-area confocal Raman spectroscopy and use method of force control device

Abstract

The invention belongs to the field of acting force control, and particularly relates to a force control device for calibrating stress through a micro-area confocal Raman spectroscopy and a use method of the force control device. The device comprises a supporting unit, a linear loading unit and a fixing frame, the supporting unit and the linear loading unit are nested in the fixing frame, the fixing frame is provided with a supporting vertical plate and a scale plate, the supporting vertical plate is of a T-shaped frame structure, the supporting unit is installed on the transverse part of the T-shaped frame structure in the transverse direction, and the scale plate is installed on the supporting unit. The linear loading unit is longitudinally mounted at the longitudinal part of the T-shaped frame structure, so that the supporting unit is perpendicular to the linear loading unit, a supporting rod of the supporting unit corresponds to a pressure rod of the linear loading unit, and a test material is arranged between the supporting rod and the pressure rod. In the Raman signal acquisition process, the acting force borne by the test material is kept constant, so that the corresponding relation between the stress of the test material and the Raman peak displacement of the test material is accurately established, further stress calibration is performed, and the problems that the acting force is easy to return and the calibration precision is insufficient in the prior art are solved.

Description

Technical Field

[0001] The present invention belongs to the field of force control, and specifically relates to a force control device for calibrating stress using micro-area confocal Raman spectroscopy and a method for using the device. The device is particularly suitable for analyzing the thermal stress distribution of substrates and coatings of high-purity silicon carbide precision ceramic components (such as wafer boats and furnace tubes) that are indispensable in semiconductor manufacturing processes. Background Art

[0002] The semiconductor industry is a strategic, fundamental, and pioneering industry that supports the sustainable development of my country's economy and safeguards national security. Due to their excellent overall performance, precision ceramic components are widely used in semiconductor manufacturing processes, including but not limited to wafer oxidation, diffusion, epitaxy, ion implantation, and thin film deposition. They are an indispensable and important consumable component in the semiconductor industry.

[0003] Silicon carbide (SiC) boats and furnace tubes are core ceramic components used in the high-temperature oxidation and diffusion processes of wafers. To prevent contamination by impurities, high purity is required for these ceramic components. In actual production, 6N (purity greater than 99.9999%) is an acceptable component purity for the diffusion process. However, due to process limitations for large-scale SiC ceramic components, SiC boats and furnace tubes used worldwide utilize a sintered 4N (purity greater than 99.99%) SiC substrate and a chemical vapor deposition (CVD) 6N SiC protective coating. Because the coating is composed of β-phase SiC and the substrate is a composite of α-phase SiC and silicon, the difference in thermal expansion coefficients between the coating and substrate inevitably results in thermal stress. However, reliable equipment is lacking to accurately assess the distribution of thermal stress within the substrate and near the interface, as well as the stress values.

[0004] Patent publication number CN109342402A proposes a method for measuring stress in ceramic materials based on Raman spectroscopy. This method generates different Raman spectra generated by applying varying pressures to multiple ceramic specimens, determines the peak positions of the Raman spectra, and then uses a graph showing the relationship between stress and the frequency shift of the Raman spectra peaks to determine the Raman stress coefficient of the ceramic material. The internal stress of a ceramic specimen with unknown internal stress can be calculated using the Raman stress coefficient and the frequency shift of the main peak of the Raman spectrum corresponding to the specimen. However, this method does not involve a dynamic force compensation mechanism, and the applied force during loading can be easily unstable due to mechanical setbacks or temperature fluctuations, affecting calibration accuracy.

[0005] Patent publication number CN116678866A proposes a multi-polarization-state incident micro-Raman spectroscopy stress detection method and device for microscale triaxial principal stress detection in silicon and gallium arsenide semiconductor devices. This method utilizes radially polarized light incident through a high numerical aperture (NA) objective lens in combination with a polarizer to simultaneously excite and capture longitudinal optical (LO) and transverse optical (TO) phonons. It also utilizes azimuthally polarized light incident through a high NA objective lens in combination with a polarizer to independently excite and capture LO phonons. Because the device relies on complex optical polarization modulation techniques to separate TO / LO peaks, it is highly integrated and complex to operate. It also fails to address the stability issues of force-controlled loading and cannot be directly applied to stress calibration scenarios requiring mechanical loading.

[0006] Patent publication number CN105547543A proposes a Raman spectrometer and method for measuring surface stress in tempered glass. The Raman spectrometer includes a light source, a Raman signal acquisition device, and a Raman spectrum analyzer. The Raman signal scattered by the sample is reflected by a semi-transparent mirror before passing through an imaging lens and an exit slit into the spectrometer for spectral analysis. However, the Z-axis scanning method, which focuses on detecting stress on the glass surface, does not involve an external force loading mechanism, making it impossible to establish a quantitative relationship between active force and Raman frequency shift. Summary of the Invention

[0007] The purpose of the present invention is to provide a force control device for calibrating stress using micro-area confocal Raman spectroscopy and its use method. Dynamic constant force loading is achieved through a spring compensation mechanism and a sliding block linkage structure, which solves the problems of easy force retreat and insufficient calibration accuracy in the prior art. It is used to calibrate the relationship between material stress and Raman peak displacement.

[0008] The above-mentioned purpose of the present invention is achieved through the following technical solutions:

[0009] A force control device for calibrating stress using micro-area confocal Raman spectroscopy is disclosed. The device comprises a support unit, a linear loading unit, and a fixed frame. The support unit and the linear loading unit are nested within the fixed frame. The specific structure is as follows:

[0010] The support unit is provided with a handwheel, a pointer, a guide rail, a support rod, a slider pair, and a lifting screw. The handwheel is installed at one end of the lifting screw. The two sliders of the slider pair are symmetrically installed on the lifting screw. The guide rail is arranged in parallel on one side of the lifting screw. One side of the two sliders of the slider pair is in sliding cooperation with the guide rail. The pointers are respectively fixed to the top of the two sliders of the slider pair. The other sides of the two sliders of the slider pair are respectively provided with vertical semicircular grooves. The support rod is embedded in the semicircular groove. The axis of the semicircular groove is on the extension line of the center line of the pointer, so as to support the test material.

[0011] The linear loading unit is provided with a pressure rod, a replaceable pressure block, a transition plate, a force sensor, a second sliding block, a first sliding block, a linear guide rail, a thrust screw, a handle, and a spring. A handle is installed at one end of the thrust screw, and the other end of the thrust screw is connected to the first sliding block by a thread. The first sliding block is driven by the thrust screw to perform linear motion; the second sliding block corresponds to the first sliding block and is provided with two parallel springs. One side of the second sliding block is connected to the first sliding block through the spring. The second sliding block and the first sliding block are installed on two parallel linear guide rails and are slidably matched with the linear guide rails; a force sensor, a transition plate, and a replaceable pressure block are sequentially arranged on the other side of the second sliding block, and the force sensor and the second sliding block are locked with screws. One side of the replaceable pressure block is movably connected to the transition plate. One or more vertical semicircular grooves are opened on the other side of the replaceable pressure block, and the pressure rod is embedded in the semicircular groove to compress the test material.

[0012] The force control device for calibrating stress using micro-area confocal Raman spectroscopy has a fixed frame provided with a supporting plate and a scale plate. The supporting plate is a T-shaped frame structure, and the middle of the side of the horizontal part of the supporting plate is opened. The scale plate is provided at the opening, and the upper end surface of the scale plate is provided with scale lines.

[0013] The force control device for calibrating stress using micro-area confocal Raman spectroscopy is characterized in that the support unit is installed horizontally on the horizontal part of the T-shaped frame structure, and the linear loading unit is installed vertically on the longitudinal part of the T-shaped frame structure, so that the support unit and the linear loading unit are perpendicular to each other, the support rod of the support unit corresponds to the pressure rod of the linear loading unit, and the test material is arranged between the support rod and the pressure rod.

[0014] In the force control device for calibrating stress using micro-area confocal Raman spectroscopy, the support unit corresponds to the scale lines on the scale plate through the pointer on the slider pair, the pointer direction is perpendicular to the moving direction of the slider pair, and the span is indicated by the scale lines.

[0015] The force control device for calibrating stress using micro-area confocal Raman spectroscopy is provided with a left-handed thread segment and a right-handed thread segment with opposite rotation directions on the lifting screw. One slider is threadedly connected to the left-handed thread segment, and the other slider is threadedly connected to the right-handed thread segment. When the lifting screw rotates, the left-handed thread segment drives one slider to move, and the right-handed thread segment drives the other slider to move, thereby achieving a symmetrical opening and closing motion trajectory.

[0016] The method for using the force control device for calibrating stress using micro-area confocal Raman spectroscopy is as follows: the force applied by the thrust screw to the first sliding block drives the spring in the second sliding block to produce compressive deformation. At this time, the spring applies a force to the second sliding block. The force acts on the center of the pressure surface of the test material through the second sliding block, the transition plate, the replaceable pressure block and the pressure rod in sequence. The stress generated by the test material under the force acts on the force sensor, and the stress causes the Raman peak to shift. Therefore, by collecting the Raman signal, the relationship between stress and offset is established, and the stress of the material can be calibrated using Raman spectroscopy.

[0017] In the method for using the force control device for calibrating stress using micro-area confocal Raman spectroscopy, the stress is stabilized by the spring in the second sliding block, thereby achieving constant force loading.

[0018] The method for using the force control device for calibrating stress using micro-area confocal Raman spectroscopy is as follows: in the support unit, rotating the handwheel drives the jacking screw to rotate. At this time, the slider pair performs synchronous and symmetrical opening and closing movements driven by the jacking screw. The distance between the two pointers is the center span of the two support rods, which is adjusted to the span required by the test material as needed.

[0019] The method for using the force control device for calibrating stress using the micro-area confocal Raman spectroscopy method is as follows: in the linear loading unit, the rotating handle drives the thrust screw to perform reciprocating motion. When moving to the left, the thrust screw presses against the first sliding block, pushing it to continue moving to the left; at the same time, the spring located at the connection is pushed to the left by the first sliding block to press against the second sliding block, causing it to move to the left. The force sensor, transition plate and replaceable pressure block connected by screws at the left end of the second sliding block move to the left under the force of the second sliding block. Finally, the pressure rod on the replaceable pressure block presses against the pressure surface of the test material, and works together with the support rod of the support unit to clamp and fix the test material. The force is adjustable within the range of 0 to 600N and remains stable.

[0020] The method for using the force control device for calibrating stress using micro-area confocal Raman spectroscopy maintains a constant force on the test material during Raman signal acquisition, thereby accurately establishing the corresponding relationship between the stress of the test material and its Raman peak displacement, and then performing stress calibration.

[0021] The design concept of the present invention is:

[0022] On the platform constructed by the present invention, a quantitative relationship between the Raman characteristic spectrum and the magnitude of thermal stress is first established, and then the distribution of thermal stress in the matrix and near the interface is described based on this quantitative relationship. In the present invention, the compressive force applied to the first sliding block by the thrust screw drives the spring in the second sliding block to produce compressive deformation. At this time, the spring generates a force on the second sliding block, which then acts on the center of the pressure surface of the material through the second sliding block, the transition plate, the replaceable pressure block and the pressure rod in sequence. The stress generated by the force on the material acts on the force sensor. During the test process, when the linear loading unit produces a slight change, the spring in the second sliding block compensates for the force, thereby significantly enhancing the stability of the force and improving the accuracy of the Raman peak displacement calibration.

[0023] The dynamic linkage between the sliding block and the spring of the present invention realizes dynamic force compensation when the thrust screw has a small displacement change through the spring connection design between the first sliding block and the second sliding block. The thrust screw pushes the first sliding block to compress the spring, and the spring deformation is converted into a constant force (adjustable within the range of 0 to 600N) through Hooke's law. The second sliding block transmits the force to the pressure rod to avoid the influence of mechanical backoff, solves the calibration error problem caused by mechanical backoff in the prior art, and realizes dynamic constant force loading.

[0024] The advantages and beneficial effects of the present invention are:

[0025] 1. Existing technologies mostly rely on external constant pressure devices or hydraulic systems, which cannot dynamically compensate for force values ​​when there are small displacement changes. The force control device of the present invention uses the coordinated cooperation of a fixed frame, a support unit, and a linear loading unit, and uses the compensation effect of the spring to achieve constant force loading. The spring connection structure (the spring between the first and second sliding blocks) adjusts the applied force in real time through compression deformation. Combined with replaceable pressure blocks, it adapts to test materials of various sizes and shapes (such as silicon carbide wafer boats, furnace tubes, etc.), significantly improving the calibration accuracy of the relationship between Raman peak displacement and stress.

[0026] 2. The present invention uses the spring in the second sliding block to compensate for the acting force so as to achieve constant force loading. At the same time, the device and method are simple and effective, with flexible operation process, wide applicability and strong practicality.

[0027] 3. The sliding block opening and closing design and pointer span adjustment function of the support unit of the present invention further enhance the applicability and operational flexibility of the device.

[0028] 4. The present invention provides a calibration device and method for testing residual stress of materials using Raman spectroscopy, and can be extended to other testing methods, with a wide range of applications and strong practicality. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The drawings described herein are used to provide further understanding of the present invention and constitute a part of this application. The illustrative examples of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0030] Figure 1 The figure is a schematic structural diagram of a force control device for calibrating stress using Raman spectroscopy according to the present invention.

[0031] Figure 2 It is a top cross-sectional view of the linear loading unit of the present invention.

[0032] Figure 3 It is a schematic diagram of the support unit structure of the present invention.

[0033] Figure 4 It is a schematic structural diagram of the linear loading unit of the present invention.

[0034] In the figure: 1. Support unit, 11. Handwheel, 12. Pointer, 13. Guide rail, 14. Support rod, 15. Slider pair, 16. Lifting screw; 2. Linear loading unit, 21. Pressure rod, 22. Replaceable pressure block, 23. Transition plate, 24. Force sensor, 25. Second sliding block, 26. First sliding block, 27. Linear guide rail, 28. Thrust screw, 29. Handle, 210. Spring; 3. Fixed frame, 31. Support vertical plate; 32. Scale plate; 4. Test material. DETAILED DESCRIPTION

[0035] It should be understood that in the description of this application, the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "lateral", "longitudinal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application. The terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated, that is, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In addition, unless otherwise specified, "multiple" means two or more.

[0036] The details and specific implementation methods of the present invention are further described below with reference to the accompanying drawings.

[0037] like Figures 1-4As shown, a force control device for calibrating stress using Raman spectroscopy according to the present invention mainly comprises: a support unit 1, a linear loading unit 2 and a fixed frame 3. The support unit 1 and the linear loading unit 2 are nested in the fixed frame 3. The specific structure is as follows:

[0038] Fixed frame 3 is provided with support uprights 31 and a scale plate 32. Support uprights 31 are T-shaped structures, with a central opening on the side of the transverse portion of support uprights 31. Scale plate 32 is disposed at the opening, and scale lines are provided on the upper end surface of scale plate 32. Support unit 1 is mounted transversely to the transverse portion of the T-shaped frame structure, and linear loading unit 2 is mounted longitudinally to the longitudinal portion of the T-shaped frame structure, such that support unit 1 and linear loading unit 2 are perpendicular. Support rod 14 of support unit 1 corresponds to pressure rod 21 of linear loading unit 2, and test material 4 is positioned between support rod 14 and pressure rod 21. Support unit 1 indicates span by aligning pointer 12 on slider pair 15 with scale lines on scale plate 32.

[0039] like Figure 3 As shown, the support unit 1 is provided with a handwheel 11, a pointer 12, a guide rail 13, a support rod 14, a slider pair 15, and a lifting screw 16. The lifting screw 16 is passed through the transverse part of the support vertical plate 31 and is transmission-connected to the support vertical plate 31 through a bearing. The handwheel 11 is installed at one end of the lifting screw 16 on the outside of the transverse part of the support vertical plate 31; the two sliders of the slider pair 15 are symmetrically installed on the lifting screw 16, and the lifting screw 16 is provided with a left-handed thread segment and a right-handed thread segment with opposite rotation directions. One slider is threadedly connected to the left-handed thread segment, and the other slider is threadedly connected to the right-handed thread segment. In this way, when the lifting screw 16 rotates, the left-handed thread segment drives one slider to move, and the right-handed thread segment drives the other slider to move, so as to achieve a symmetrical opening and closing motion trajectory. A guide rail 13 is provided parallel to one side of the lifting screw 16. The two sliders of the slider pair 15 slide in contact with the guide rail 13. Pointers 12 are fixed to the top ends of the two sliders of the slider pair 15. Pointers 12 are non-rotatable and their direction is perpendicular to the direction of movement of the slider pair 15. Vertical semicircular grooves are defined on the other sides of the two sliders of the slider pair 15. Support rods 14 are embedded in these semicircular grooves, with their axes extending from the centerlines of pointers 12 to support the test material 4. In the support unit, rotating the handwheel 11 drives the lifting screw 16. At this point, the slider pair 15, driven by the lifting screw 16, performs a synchronous and symmetrical opening and closing motion. The distance between the two pointers 12 corresponds to the center-to-center span of the two support rods 14, which can be adjusted to the required span of the test material 4 as needed.

[0040] like Figure 2 、 Figure 4As shown, the linear loading unit 2 is provided with a pressure bar 21, a replaceable pressure block 22, a transition plate 23, a force sensor 24, a second sliding block 25, a first sliding block 26, a linear guide 27, a thrust screw 28, a handle 29, and a spring 210. The thrust screw 28 is passed through the longitudinal part of the support vertical plate 31 and is transmission-connected to the support vertical plate 31 through a bearing. A handle 29 is installed at one end of the thrust screw 28 on the outer side of the longitudinal part of the support vertical plate 31. The other end of the thrust screw 28 is threadedly connected to the first sliding block 26. The first sliding block 26 is driven by the thrust screw 28 to perform linear motion; the second sliding block 25 corresponds to the first sliding block 26. Two parallel springs 210 are provided in the second sliding block 25. One side of the second sliding block 25 is connected to the first sliding block 26 through the spring 210. The second sliding block 25 and the first sliding block 26 are installed on two parallel linear guides 27 and are in sliding fit with the linear guides 27. A force sensor 24, a transition plate 23, and a replaceable pressure block 22 are sequentially arranged on the other side of the second sliding block 25. The force sensor 24 and the second sliding block 25 are fastened with screws. One side of the replaceable pressure block 22 is movably connected to the transition plate 23. One or more vertical semicircular grooves are provided on the other side of the replaceable pressure block 22. The axis of a single semicircular groove is located on the symmetry axis of the two pointers 12 in the support unit 1. The pressure rod 21 is embedded in the semicircular groove to compress the test material 4.

[0041] In the linear loading unit 2, rotating the handle 29 drives the thrust screw 28 to reciprocate. When moving leftward, the thrust screw 28 presses against the first sliding block 26, pushing it further leftward. Simultaneously, the spring at the joint is pushed leftward by the first sliding block 26 against the second sliding block 25, causing it to move leftward. The force of the second sliding block 25 acts on the force sensor 24, transition plate 23, and replaceable pressure block 22, which are screwed together at the left end of the second sliding block 25. Finally, the pressure rod 21 on the replaceable pressure block 25 presses against the pressure surface of the test material 4, working together with the support rod 14 of the support unit 1 to clamp and secure the test material 4. The applied force is adjustable within a range of 0 to 200 N and remains stable. During Raman signal acquisition, the force acting on the test material 4 can be maintained constant, thereby accurately establishing the corresponding relationship between the stress of the test material and its Raman peak shift, thereby performing stress calibration.

[0042] The force control device of the present invention has the advantages of a horizontal loading force direction and a simple transmission structure. However, over long periods of operation, the force may show a phenomenon of force retreat. To address this, the present invention uses a spring connecting the first and second sliding blocks to compensate for the force retreat, thereby improving the stability of the force.

[0043] like Figures 1-4As shown, the force control device of the present invention implements a method for calibrating material stress using micro-area confocal Raman spectroscopy. Based on the influence of residual stress on Raman spectroscopy, residual stress changes the atomic spacing and lattice constant within the material, thereby affecting the lattice vibration mode (phonon energy), which manifests as a Raman peak shift. The force applied by the thrust screw 28 to the first sliding block 26 drives the spring 210 in the second sliding block 25 to compress and deform. At this time, the spring 210 applies a force to the second sliding block 25. The force acts sequentially through the second sliding block 25, the transition plate 23, the replaceable pressure block 22, and the pressure rod 21, acting on the center of the pressure-bearing surface of the test material 4. The stress generated by the test material 4 acts on the force sensor 24, causing the stress to cause a Raman peak shift, thereby establishing a relationship between stress and offset, and realizing the stress calibration of the material using Raman spectroscopy. The stress is stabilized by the spring 210 in the second sliding block 25, thereby achieving constant force loading.

[0044] Implementation results show that the present invention significantly improves the accuracy and applicability of stress calibration using Raman spectroscopy through the adaptive design of the spring compensation structure, the slider opening and closing mechanism, and the replaceable pressure block.

[0045] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. A person skilled in the art will readily appreciate that the present invention is susceptible to numerous modifications and variations. Any modifications, equivalent substitutions, or improvements to the present invention are intended to fall within the scope of protection of the present invention.

Claims

1. A force control device for calibrating stress using micro-area confocal Raman spectroscopy, characterized in that: The device includes a support unit, a linear loading unit and a fixed frame. The support unit and the linear loading unit are nested in the fixed frame. The specific structure is as follows: The support unit is provided with a handwheel, a pointer, a guide rail, a support rod, a slider pair, and a lifting screw. The handwheel is installed at one end of the lifting screw. The two sliders of the slider pair are symmetrically installed on the lifting screw. The guide rail is arranged in parallel on one side of the lifting screw. One side of the two sliders of the slider pair is in sliding cooperation with the guide rail. The pointers are respectively fixed to the top of the two sliders of the slider pair. The other sides of the two sliders of the slider pair are respectively provided with vertical semicircular grooves. The support rod is embedded in the semicircular groove. The axis of the semicircular groove is on the extension line of the center line of the pointer, so as to support the test material. The linear loading unit is provided with a pressure rod, a replaceable pressure block, a transition plate, a force sensor, a second sliding block, a first sliding block, a linear guide rail, a thrust screw, a handle, and a spring. A handle is installed at one end of the thrust screw, and the other end of the thrust screw is connected to the first sliding block by a thread. The first sliding block is driven by the thrust screw to perform linear motion; the second sliding block corresponds to the first sliding block and is provided with two parallel springs. One side of the second sliding block is connected to the first sliding block through the spring. The second sliding block and the first sliding block are installed on two parallel linear guide rails and are slidably matched with the linear guide rails; a force sensor, a transition plate, and a replaceable pressure block are sequentially arranged on the other side of the second sliding block, and the force sensor and the second sliding block are locked with screws. One side of the replaceable pressure block is movably connected to the transition plate. One or more vertical semicircular grooves are opened on the other side of the replaceable pressure block, and the pressure rod is embedded in the semicircular groove to compress the test material.

2. The force control device for calibrating stress using micro-area confocal Raman spectroscopy according to claim 1, characterized in that: The fixed frame is provided with a supporting plate and a scale plate. The supporting plate is a T-shaped frame structure. The middle side of the horizontal part of the supporting plate is open. The scale plate is provided at the opening, and the upper end surface of the scale plate is provided with scale lines.

3. The force control device for calibrating stress using micro-area confocal Raman spectroscopy according to claim 2, characterized in that: The support unit is installed in the transverse direction on the transverse part of the T-shaped frame structure, and the linear loading unit is installed in the longitudinal direction on the longitudinal part of the T-shaped frame structure, so that the support unit is perpendicular to the linear loading unit, the support rod of the support unit corresponds to the pressure rod of the linear loading unit, and the test material is set between the support rod and the pressure rod.

4. The force control device for calibrating stress using micro-area confocal Raman spectroscopy according to claim 1, characterized in that: The support unit corresponds to the scale line on the scale plate through the pointer on the slider pair, the pointer direction is perpendicular to the moving direction of the slider pair, and the span is indicated by the scale line.

5. The force control device for calibrating stress using micro-area confocal Raman spectroscopy according to claim 1, characterized in that: The lifting screw is provided with a left-handed thread section and a right-handed thread section with opposite rotation directions. One slider is connected to the left-handed thread section by a thread, and the other slider is connected to the right-handed thread section by a thread. When the lifting screw rotates, the left-handed thread section drives one slider to move, and the right-handed thread section drives the other slider to move, so as to achieve a symmetrical opening and closing motion trajectory.

6. A method for using the force control device for calibrating stress using micro-area confocal Raman spectroscopy according to any one of claims 1 to 5, characterized in that: The force applied to the first sliding block by the thrust screw drives the spring in the second sliding block to produce compression deformation. At this time, the spring applies a force to the second sliding block. The force passes through the second sliding block, the transition plate, the replaceable pressure block and the pressure rod in sequence, and acts on the center of the pressure surface of the test material. The stress generated by the test material under the force acts on the force sensor. The stress causes the Raman peak to shift. By collecting the Raman signal, the relationship between stress and offset is established, and the stress of the material can be calibrated using Raman spectroscopy.

7. The method for using the force control device for calibrating stress using micro-area confocal Raman spectroscopy according to claim 6, characterized in that: The stress is stabilized by the spring in the second sliding block to achieve constant force loading.

8. The method for using the force control device for calibrating stress using micro-area confocal Raman spectroscopy according to claim 6, characterized in that: In the support unit, rotating the handwheel drives the jacking screw to rotate. At this time, the slider pair opens and closes synchronously and symmetrically under the drive of the jacking screw. The distance between the two pointers is the center span of the two support rods, which can be adjusted to the span required by the test material as needed.

9. The method for using the force control device for calibrating stress using micro-area confocal Raman spectroscopy according to claim 6, characterized in that: In the linear loading unit, the rotating handle drives the thrust screw to perform reciprocating motion. When moving to the left, the thrust screw presses against the first sliding block, pushing it to continue moving to the left. At the same time, the spring located at the connection is pushed to the left by the first sliding block to press against the second sliding block, causing it to move to the left. The force sensor, transition plate and replaceable pressure block connected by screws at the left end of the second sliding block move to the left under the force of the second sliding block. Finally, the pressure rod on the replaceable pressure block presses against the pressure surface of the test material, and works together with the support rod of the support unit to clamp and fix the test material. The force is adjustable within the range of 0 to 600N and remains stable.

10. The method for using the force control device for calibrating stress using micro-area confocal Raman spectroscopy according to claim 6, characterized in that: During the Raman signal acquisition process, the force acting on the test material remains constant, so that the corresponding relationship between the stress of the test material and its Raman peak displacement can be accurately established, and then stress calibration can be performed.

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