High-precision grinding machine based on laser measurement compensation and use method

Abstract

The application discloses a high-precision grinding machine based on laser measurement compensation and a use method, wherein lasers and four-quadrant photoelectric detectors of the grinding machine are symmetrically distributed on both sides of a cantilever, the lasers emit laser beams to irradiate on a sample surface, the laser beams are reflected by the sample to enter the four-quadrant photoelectric detectors, and electric signals (voltage or current) are output, so that the position of a grinding surface on a Z axis can be accurately measured, and the measurement precision can reach a nanometer level. First, an actual grinding amount after completion of first-round grinding is measured, an actual grinding efficiency is calculated, and then a second-round grinding plan is formulated according to the actual grinding efficiency, so that the difference between the actual grinding amount and a required grinding removal amount is compensated, and the required grinding removal amount can be accurately obtained. Nitrogen blowing is required on the sample surface before laser measurement after grinding, so as to avoid interference of a liquid film on measurement. The application realizes accurate control of the grinding amount in the grinding process, and can effectively improve work efficiency and is convenient to operate.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of micro-electro-mechanical system (MEMS) manufacturing and processing, and particularly relates to a high-precision grinder based on laser measurement compensation and a use method. BACKGROUND

[0002] MEMS is the integration of micro-circuits and micro-machines on a chip according to functional requirements, mainly including micro-sensors, micro-actuators and micro-energy sources, and has a wide application prospect in the fields of machinery, materials, aerospace, chemical industry, medical treatment, automobiles and consumer electronics, etc. due to its small size, light weight, low power consumption and high reliability. The size of a MEMS device is usually in the order of millimeters or micrometers, and therefore the thickness of the processing substrate has strict requirements. Common substrates in the field of MEMS currently include silicon (Si), indium phosphide (InP), silicon carbide (SiC), gallium nitride (GaN), diamond (C) and sapphire (Al2O3), etc. The thickness of a finished wafer or chip of such materials is generally in the range of several hundred micrometers to several millimeters. If a MEMS device is to be manufactured and processed on this basis, the substrate needs to be thinned to the designed size according to actual requirements in many cases, which not only can realize the function of the device, but also can improve the performance and working efficiency of the device per unit volume, and can meet the requirements of environmental adaptability by effectively reducing the size of the device. Grinding is an effective way of thinning.

[0003] A MEMS device is a miniature high-precision intelligent system, and has very high requirements for the thinning precision of the substrate and the surface quality of the thinned sample. The existing various types of grinders mainly have the following problems when grinding and thinning such samples: 1. Although there is a pressure feedback system, the grinding process is a dynamic process, and the control of the pressure is actually a range value, which directly leads to the deviation between the actual grinding thickness and the set grinding feed amount; 2. The optical microscope is generally used to measure the grinding amount of the sample, and the limit resolution of the optical microscope can only reach 0.2 μm, and a smaller working distance is required to achieve a higher resolution. The principle design of the grinder and the structure of the protective cover set to prevent the splashing of the grinding liquid and the grinding dust make it difficult to obtain a smaller working distance, and therefore the smaller grinding amount cannot be accurately measured, and the liquid film layer remaining on the grinding surface also affects the focusing resolution of the microscope on the sample; 3. If the sample is taken out, the grinding amount is measured on other observation instruments, and then further grinding is performed, which is a cycle, greatly reducing the working efficiency of the user, and the position and angle errors are also introduced when the sample is manually loaded. SUMMARY

[0004] The present application provides a high-precision grinder based on laser measurement compensation and a use method to solve the above problems, and realizes accurate control of the grinding amount during grinding and improves the working efficiency.

[0005] A high-precision grinder based on laser measurement compensation, the grinder comprising a base, a grinder switch, a controller, a motor displacement system, a cantilever, a sample clamp, a motor spindle, a grinding tool table, a grinding disc, a feed knob, a spindle rotation switch, a spindle X-axis movement knob, a spindle Y-axis movement knob, a nitrogen generator, a nitrogen generator switch, a nitrogen purge nozzle, a guide rail, a laser, a laser X-axis adjustment knob, a laser Y-axis adjustment knob, a laser angle adjustment knob, a four-quadrant photodetector, a four-quadrant photodetector X-axis adjustment knob, a four-quadrant photodetector Y-axis adjustment knob, and a four-quadrant photodetector angle adjustment knob, a liquid pump, a flow guide pipe, a liquid pool, a microscope, a protective cover, and a pressure-sensitive pad. Among them: the controller, the motor displacement system, the cantilever, the nitrogen generator, the laser, the four-quadrant photodetector, the microscope, the liquid pump, and the liquid pool are all fixed on the base; the base is provided with the grinder switch, the nitrogen generator switch, the spindle rotation switch, and the feed knob; the sample clamp is located at the top of the cantilever to fix the sample, the grinding disc is installed on the grinding tool table at the top of the motor spindle, the motor spindle is part of the motor displacement system, the feed knob controls the movement of the motor spindle in the Z direction, the spindle X-axis movement knob and the spindle Y-axis movement knob control the movement of the motor spindle in the X direction and the Y direction, and the spindle rotation switch controls the rotation of the motor spindle; the nitrogen generator switch controls the nitrogen generator to generate nitrogen; the nitrogen purge nozzle is connected to the nitrogen generator and can move along the guide rail opposite the grinding surface; the laser and the four-quadrant photodetector are symmetrically distributed on both sides of the cantilever and maintain a certain angle with the grinding surface, the laser X-axis adjustment knob and the laser Y-axis adjustment knob can adjust the position of the laser in the X-axis and the Y-axis, the laser angle adjustment knob can adjust the laser incidence angle, the four-quadrant photodetector X-axis adjustment knob and the four-quadrant photodetector Y-axis adjustment knob can adjust the position of the four-quadrant photodetector in the X-axis and the Y-axis, and the four-quadrant photodetector angle adjustment knob can adjust the receiving angle of the four-quadrant photodetector; the flow guide pipe is connected to the liquid pump and can also move along the guide rail, and cooperates with the nitrogen purge nozzle to move without interfering with each other; the protective cover can be completely buckled with the base, and after buckling, the pressure-sensitive pad in the installation groove can be compressed, covering the entire grinding area, including the cantilever, the sample clamp, the motor spindle, the grinding tool table, the grinding disc, the nitrogen purge nozzle, the guide rail, and the flow guide pipe, and the upper part has a through hole for microscope observation, the lower part is open, and below is the liquid pool for containing the liquid and grinding dust during processing; the microscope is arranged above the protective cover and opposite the observation through hole.

[0006] The laser and the four-quadrant photodetector are symmetrically distributed on both sides of the cantilever, the laser emitted by the laser irradiates on the sample grinding surface, and is reflected into the four-quadrant photodetector via the sample surface to generate an electrical signal (voltage or current) output, and the position of the grinding surface in the Z direction is measured.

[0007] Nitrogen blowing nozzle is located in the upper position of the grinding surface, inside the protective cover when the protective cover is closed, from top to bottom at a certain angle to the grinding surface, can move left and right, liquid and grinding film layer of the grinding surface blowing, can be repeated until the liquid film residue.

[0008] Pressure sensitive pad is located in the installation groove: when the protective cover is closed, the pressure sensitive pad is compressed, the motor spindle can rotate at high speed for grinding, at this time the laser cannot be started; when the protective cover is removed, the pressure sensitive pad cannot sense the pressure, the motor spindle cannot rotate, while the laser can be started for accurate measurement.

[0009] When the protective cover is closed, the laser and the four-quadrant photodetector are located outside the protective cover and are not affected by the splashing of liquid and grinding.

[0010] When the protective cover is closed, the nitrogen blowing nozzle and the flow guide pipe are located inside the protective cover, and can move left and right along the guide rail, and move in cooperation with each other, and are functionally interlocked, so that only one of the nitrogen blowing nozzle and the flow guide pipe can work at a time.

[0011] The positions of the motor spindle, the nitrogen blowing nozzle, the flow guide pipe, the laser, the four-quadrant photodetector, the protective cover and the microscope relative to the sample grinding surface need to be coordinated, and the grinding surface can be blown by nitrogen and measured by laser under any condition of the motor spindle retraction.

[0012] A use method of the high-precision grinder based on the above, comprising the following operation steps:

[0013] Step one, open the grinder, load the sample clamp with the sample fixed thereon to the cantilever, observe and adjust the angle and position of the sample by using the microscope, load the polishing plate with appropriate particle size on the motor spindle, and control the Y-axis movement knob of the spindle to align the center positions of the polishing plate and the sample in the Y direction;

[0014] Step two, turn on the laser, first adjust the angles of the laser and the four-quadrant photodetector by using the angle adjustment knobs of the laser and the four-quadrant photodetector, then adjust the position of the laser by using the X-axis and Y-axis adjustment knobs of the laser, and finally adjust the position of the four-quadrant photodetector by using the X-axis and Y-axis adjustment knobs of the four-quadrant photodetector, so that the laser reflection spot enters the center of the four-quadrant photodetector, and the electrical signal output by the photodetector corresponds to the position of the grinding surface in the Z axis, and it is considered that the grinding surface is located at the position with a grinding amount of 0 at this time;

[0015] Step three, turn off the laser, close the protective cover, adjust the position of the flow guide pipe, and turn on the liquid pump switch to make the grinding liquid flow to the grinding surface through the flow guide pipe;

[0016] Step four, set the step size on the controller, rotate the feed knob, each rotation of the motor spindle drives the grinding disc to feed a step size on the Z axis, and controls the spindle X axis movement knob to move towards the sample in the X direction, coarse grinding position, when the grinding disc contacts the sample, retreat the motor spindle, set a smaller step size, turn on the spindle rotation switch, and slowly move the grinding disc using the feed knob to fine the grinding position;

[0017] Step five, when the pressure display value on the controller reaches the required value, start grinding, control the spindle X axis movement knob to reciprocate several times, and then continue grinding with the corresponding step size each time;

[0018] Step six, the mirror surface grinding plan needs to be formulated according to the required grinding removal amount, the pre-set grinding amount of this round should be slightly smaller than the grinding removal amount, the step size is set from large to small, and different step sizes need to replace grinding discs with different particle sizes;

[0019] Step seven, after the grinding is completed, turn off the spindle rotation switch, retreat the motor spindle, turn off the liquid pump, move the flow guide pipe along the guide rail, turn on the nitrogen generator, and move the nitrogen gas to the left and right of the spray head to repeatedly blow the grinding surface until there is no residual liquid film, and then turn off the nitrogen generator;

[0020] Step eight, remove the protective cover, turn on the laser, and the laser is reflected from the ground sample surface into the four-quadrant photodetector, at this time the position of the grinding surface on the Z axis displayed on the controller is the actual grinding amount, turn off the laser, and buckle the protective cover;

[0021] Step nine, calculate the actual grinding efficiency, which is the ratio of the actual grinding amount obtained by laser measurement to the pre-set grinding amount, compare the actual grinding amount with the required grinding removal amount to obtain the grinding amount difference that needs to be compensated, formulate a second round of mirror surface grinding plan according to the actual grinding efficiency, compensate for the grinding amount difference, and repeat steps four to eight to accurately obtain the required grinding removal amount.

[0022] Advantages of the present application:

[0023] 1. The laser and four-quadrant photodetector in the present application are symmetrically distributed on both sides of the cantilever, the laser emitted by the laser irradiates the sample surface, is reflected from the sample into the four-quadrant photodetector, generates an electrical signal (voltage or current) output, and can accurately measure the position of the grinding surface on the Z axis, with a measurement accuracy of nanometer level. First, the actual grinding amount after the completion of the first round of grinding is measured, the actual grinding efficiency is calculated, then a second round of grinding plan is formulated according to the actual grinding efficiency, the difference between the actual grinding amount and the required grinding removal amount is compensated, and the required grinding removal amount is accurately obtained.

[0024] 2. Nitrogen blowing head is located in the upper position of the grinding surface, and is located in the protective cover when the protective cover is closed, and can move left and right to blow the liquid and grinding dust film layer of the grinding surface, which can be repeated multiple times until the liquid film is residual-free, preventing it from interfering with the laser and other measurements.

[0025] 3. The present application has high safety, and the pressure-sensitive pad is located in the base mounting groove: when the protective cover is closed and the pressure-sensitive pad is compressed, the motor spindle can rotate at high speed for grinding, at which time the laser cannot be started; when the protective cover is opened and the pressure-sensitive pad cannot sense the pressure, the motor spindle cannot rotate, and the laser can be started for accurate measurement.

[0026] 4. The present application is easy to operate, has a delicate structure design, and has strong practicality. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 is a top view of the present application;

[0028] Figure 2 is a rear view of the present application;

[0029] Figure 3 is an enlarged view of A of Figure 2 ; is a B-B sectional view of ; is a B-B sectional view of

[0030] ; is a B-B sectional view of Figure 4 ; is a B-B sectional view of Figure 2 ; is a B-B sectional view of ; is a B-B sectional view of

[0031] ; is a B-B sectional view of Figure 5 ; is a B-B sectional view of ; is a B-B sectional view of

[0032] ; is a B-B sectional view of Figure 6 ; is a B-B sectional view of ; is a B-B sectional view of

[0033] ; is a B-B sectional view of Figure 7 ; is a B-B sectional view of DETAILED DESCRIPTION

[0034] The following will explain the content of the present application in combination with the accompanying drawings, and changes in the structure position, size, etc. of the application, or changes in "grinding" to "polishing" without affecting the function of the application should be considered as the technical scope that can be covered by the present application. Figures 1-7

[0035] A high precision grinder based on laser measurement compensation, the grinder comprising a base 1, a grinder switch 2, a controller 3, a motor displacement system 4, a cantilever 5, a sample clamp 6, a motor spindle 8, a grinding tool table 9, a grinding wheel 10, a feed knob 11, a spindle rotation switch 12, a spindle X-axis movement knob 13, a spindle Y-axis movement knob 14, a nitrogen generator 15, a nitrogen generator switch 16, a nitrogen purge nozzle 17, a guide rail 18, a laser 19, a laser X-axis adjustment knob 20, a laser Y-axis adjustment knob 21, a laser angle adjustment knob 22, a four-quadrant photodetector 23, a four-quadrant photodetector X-axis adjustment knob 24, a four-quadrant photodetector Y-axis adjustment knob 25, and a four-quadrant photodetector angle adjustment knob 26, a liquid pump 27, a flow guide 28, a liquid pool 29, a microscope 30, a protective cover 31, a pressure-sensitive pad 32.Wherein: the controller 3, motor displacement system 4, cantilever 5, nitrogen generator 15, laser 19, four quadrant photodetector 23, microscope 30, liquid pump 27 and liquid pool 29 are fixed on the base 1; the base 1 is provided with a grinder switch 2, a nitrogen generator switch 16, a spindle rotation switch 12, and a feed knob 11; the sample clamp 6 is located at the top of the cantilever 5 to fix the sample 7, the grinding disc 10 is installed on the grinding tool table 9 at the top of the motor spindle 8, the motor spindle 8 is part of the motor displacement system 4, the feed knob 11 controls the motor spindle 8 to move along the Z direction, the spindle X-axis movement knob 13 and the spindle Y-axis movement knob 14 control the motor spindle 8 to move along the X direction and the Y direction, and the spindle rotation switch 12 controls the rotation of the motor spindle 8; the nitrogen generator switch 16 controls the nitrogen generator 15 to generate nitrogen; the nitrogen blowing nozzle 17 is connected to the nitrogen generator 15 and can move along the guide rail 18 against the grinding surface; the laser 19 and the four-quadrant photodetector 23 are symmetrically distributed on both sides of the cantilever 5 and maintain a certain angle with the grinding surface, the laser X-axis adjustment knob 20 and the laser Y-axis adjustment knob 21 can adjust the position of the laser 19 on the X-axis and the Y-axis, the laser angle adjustment knob 22 can adjust the laser incidence angle, the four-quadrant photodetector X-axis adjustment knob 24 and the four-quadrant photodetector Y-axis adjustment knob 25 can adjust the position of the four-quadrant photodetector 23 on the X-axis and the Y-axis, and the four-quadrant photodetector angle adjustment knob 26 can adjust the receiving angle of the four-quadrant photodetector 23; the flow guide pipe 28 is connected to the liquid pump 27 and can also move along the guide rail 18, and cooperates with the nitrogen blowing nozzle 17 to move without interference; the protective cover 31 can be completely buckled with the base 1, and after buckling, the pressure-sensitive pad 32 in the installation groove 33 can be pressed tightly, covering the entire grinding area, including the cantilever 5, the sample clamp 6, the motor spindle 8, the grinding tool table 9, the grinding disc 10, the nitrogen blowing nozzle 17, the guide rail 18 and the flow guide pipe 28, the upper part has an observation through hole 34 for the microscope 30, and the lower part is open, below which is the liquid pool 29, which is used to contain the liquid and grinding dust during processing; the microscope 30 is arranged above the protective cover 31 and opposite the observation through hole 34.

[0036] The laser 19 and the four-quadrant photodetector 23 are symmetrically distributed on both sides of the cantilever 5, the laser emitted by the laser 19 irradiates on the grinding surface of the sample 7, and is reflected into the four-quadrant photodetector 23 via the surface of the sample 7, generating an electrical signal (voltage or current) output, and measuring the position of the grinding surface in the Z direction.

[0037] The nitrogen blowing nozzle 17 is located at the upper position of the grinding surface and is located in the protective cover 31 when the protective cover 31 is closed, and is against the grinding surface at a certain angle from top to bottom, and can move left and right, and can blow the liquid and grinding dust film layer on the grinding surface, and can be repeated multiple times until there is no residual liquid film.

[0038] The pressure sensitive pad 32 is located in the installation groove 33: when the protective cover 31 is buckled, the pressure sensitive pad 32 is compressed, the motor spindle 8 can rotate at high speed for grinding, at this time the laser 19 cannot be started; when the protective cover 31 is removed, the pressure sensitive pad 32 cannot sense the pressure, the motor spindle 8 cannot rotate, and the laser 19 can be started for accurate measurement.

[0039] When the protective cover 31 is buckled, the laser 19 and the four-quadrant photodetector 23 are located outside the protective cover 31 and are not affected by the splashing of liquid and grinding chips.

[0040] When the protective cover 31 is buckled, the nitrogen blowing nozzle 17 and the flow guide pipe 28 are located in the protective cover 31 and can move left and right along the guide rail 18 and cooperate with each other, and the function is interlocked design, only one mechanism of the nitrogen blowing nozzle 17 and the flow guide pipe 28 can work at a time.

[0041] The position distribution of the motor spindle 8, the nitrogen blowing nozzle 17, the flow guide pipe 28, the laser 19, the four-quadrant photodetector 23, the protective cover 31 and the microscope 30 relative to the grinding surface of the sample 7 needs to be coordinated, and the nitrogen blowing and laser measurement operations can be performed on the grinding surface under any condition of the motor spindle 8 retreat.

[0042] A use method of the high-precision grinder based on the above, comprising the following operation steps:

[0043] Step one, open the grinder, load the sample clamp 6 fixed with the sample 7 to the cantilever 5, observe and adjust the angle and position of the sample 7 by using the microscope 30, load the grinding sheet 10 with appropriate particle size on the grinding tool table 9, and control the spindle Y-axis movement knob 14 to align the center positions of the grinding sheet 10 and the sample 7 in the Y direction;

[0044] Step two, open the laser 19, first adjust the angles of the laser 19 and the four-quadrant photodetector 23 by using the laser angle adjusting knob 22 and the four-quadrant photodetector angle adjusting knob 26, then adjust the position of the laser 19 by using the laser X-axis adjusting knob 20 and the laser Y-axis adjusting knob 21, and finally adjust the position of the four-quadrant photodetector 23 by using the four-quadrant photodetector X-axis adjusting knob 24 and the four-quadrant photodetector Y-axis adjusting knob 25, so that the laser reflection spot enters the center of the four-quadrant photodetector 23, and the electric signal output by the four-quadrant photodetector 23 corresponds to the position of the grinding surface on the Z axis, considering that the grinding surface is located at the position with a grinding amount of 0 at this time;

[0045] Step three, close the laser 19, buckle the protective cover 31, adjust the position of the flow guide pipe 28, and open the liquid pump 27 to make the grinding liquid flow to the grinding surface through the flow guide pipe 28;

[0046] Step four, set the step size on the controller 3, turn the feed knob 11, each turn of the motor spindle 8 drives the grinding plate 10 to feed a step size on the Z axis, while the control spindle X-axis movement knob 13 to make it in the X direction to the sample 7 close, coarse grinding position, when the grinding plate 10 and the sample 7 contact, back motor spindle 8, set a smaller step size, open the spindle rotation switch 12, using the feed knob 11 slowly move the grinding plate 10, fine grinding position;

[0047] Step five, when the controller 3 pressure display value reaches the desired value, start grinding, control spindle X-axis movement knob 13 to make it reciprocating motion several times, then each feed corresponding step size continue to grind;

[0048] Step six, according to the required grinding removal amount to formulate the corresponding mirror polishing plan, this round of pre-set grinding amount should be slightly less than the grinding removal amount, set the step size from large to small, different step size need to change different granularity of grinding plate 10;

[0049] Step seven, after the completion of the grinding, close the spindle rotation switch 12, back motor spindle 8, close the liquid pump 27, along the guide rail 18 away from the flow guide tube 28, open the nitrogen generator 15, nitrogen purge jet 17 left and right movement on the grinding surface repeatedly purging, until the liquid film no residue, close the nitrogen generator 15;

[0050] Step eight, remove the protective cover 31, open the laser 19, laser after the sample 7 surface reflection of the grinding into four quadrant photodetector 23, at this time the controller 3 display on the grinding surface in the Z axis position is the actual grinding amount, close the laser 19, buckle the protective cover 31;

[0051] Step nine, calculate the actual grinding efficiency, the ratio of the actual grinding amount and the pre-set grinding amount obtained by laser measurement, compare the actual grinding amount and the required grinding removal amount, obtain the grinding amount difference value need to be compensated, according to the actual grinding efficiency to formulate the second round of mirror polishing plan, compensate the grinding amount difference value, repeat step four ~ step eight, can accurately obtain the required grinding removal amount. Embodiment:

[0052] A 1cm*1cm sapphire substrate with GaN structure on the surface is thinned from 340μm to 240μm, and the required grinding removal amount is 100μm. The preset grinding amount of the first round of grinding is 90μm. After the sample surface is ground according to the grinding plan of this round, the mirror effect is achieved, nitrogen is blown, and then laser measurement is performed. The actual grinding amount measured is 83.286μm, the actual grinding efficiency is the ratio of the actual grinding amount and the preset grinding amount, which is 92.54%, and the grinding amount difference to be compensated is 16.714μm. Based on the actual grinding efficiency of 92.54%, the grinding plan of the second round of grinding is made as the grinding amount of 16.714μm. After grinding, the sample is blown again with nitrogen and measured by laser. The total grinding removal amount measured is 99.985nm.

[0053] The above merely describes the preferred embodiments of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art can make equivalent replacements or changes to the technical solutions and the inventive concept of the present application within the technical range disclosed by the present application, which should be covered within the protection scope of the present application.

Claims

1. A method of using a high-precision grinding machine based on laser measurement compensation, characterized by, The grinder comprises a base, a controller, a motor displacement system, a cantilever, a nitrogen generator, a laser, a four-quadrant photodetector, a microscope, a liquid pump and a liquid pool, which are all fixed on the base; the base is provided with a grinder switch, a nitrogen generator switch, a spindle rotation switch and a feeding knob; a sample clamp is located at the top end of the cantilever, and a polishing piece is installed on a polishing tool table at the top end of a motor spindle; the feeding knob controls the motor spindle to move along the Z direction; the spindle X-axis movement knob and the spindle Y-axis movement knob control the motor spindle to move along the X direction and the Y direction; the spindle rotation switch controls the rotation of the motor spindle; the nitrogen generator switch controls the nitrogen generator to generate nitrogen; a nitrogen blowing nozzle connected with the nitrogen generator is movable along a guide rail and faces the polishing surface; the laser and the four-quadrant photodetector are symmetrically distributed on both sides of the cantilever and are kept at a certain angle with the polishing surface; the laser X-axis adjustment knob and the laser Y-axis adjustment knob can adjust the position of the laser on the X axis and the Y axis; the laser angle adjustment knob can adjust the laser incidence angle; the four-quadrant photodetector X-axis adjustment knob and the four-quadrant photodetector Y-axis adjustment knob can adjust the position of the four-quadrant photodetector on the X axis and the Y axis; and the four-quadrant photodetector angle adjustment knob can adjust the receiving angle of the four-quadrant photodetector; a flow guide pipe connected with the liquid pump is also movable along the guide rail and moves in cooperation with the nitrogen blowing nozzle without interference; After the protective cover is buckled with the base, the pressure-sensitive pad in the installation groove can be compressed and the entire polishing area, including the cantilever, the sample clamp, the motor spindle, the polishing tool table, the polishing piece, the nitrogen blowing nozzle, the guide rail and the flow guide pipe, is covered; the upper part of the protective cover has a through hole for microscope observation, and the lower part is open, below which is the liquid pool used for containing the liquid and polishing chips flowing during the processing; The grinder comprises the following operation steps: Step one: open the grinder, load the sample clamp with the sample fixed thereon to the cantilever, observe and adjust the angle and position of the sample by using the microscope, load the polishing piece with a suitable particle size on the motor spindle, and control the spindle Y-axis movement knob to align the center positions of the polishing piece and the sample in the Y direction; Step two: open the laser, first adjust the angles of the laser and the four-quadrant photodetector by using the laser angle adjustment knob and the four-quadrant photodetector angle adjustment knob, then adjust the position of the laser by using the laser X-axis adjustment knob and the laser Y-axis adjustment knob, and finally adjust the position of the four-quadrant photodetector by using the four-quadrant photodetector X-axis adjustment knob and the four-quadrant photodetector Y-axis adjustment knob, so that the laser reflection spot enters the center of the four-quadrant photodetector; the electric signal output by the four-quadrant photodetector corresponds to the position of the polishing surface on the Z axis, and it is considered that the polishing surface is located at the position with a polishing amount of 0 at this time; Step three: close the laser, buckle the protective cover, adjust the position of the flow guide pipe, and open the liquid pump switch to make the polishing liquid flow to the polishing surface through the flow guide pipe; Step four, set the step size on the controller, turn the feed knob, each turn of the motor spindle drives the grinding plate to feed a step size on the Z axis, while the control spindle X axis movement knob makes it close to the sample in the X direction, coarse grinding position, when the grinding plate is in contact with the sample, the motor spindle is set back, a smaller step size is set, the spindle rotation switch is turned on, and the grinding plate is slowly moved using the feed knob to fine the grinding position; Step five, when the pressure display value on the controller reaches the required value, start grinding, control the spindle X axis movement knob to reciprocate several times, then continue to grind with the corresponding step size each time; Step six, according to the required grinding removal amount, formulate the corresponding mirror surface grinding plan, the pre-set grinding amount of this round should be slightly less than the grinding removal amount, and the step size is set from large to small, and different step sizes require different particle size grinding plates; Step seven, after the grinding is completed, turn off the spindle rotation switch, set back the motor spindle, turn off the liquid pump, move the flow guide pipe along the guide rail, turn on the nitrogen generator, and move the nitrogen blowing nozzle left and right to repeatedly blow the grinding surface until there is no residual liquid film, and then turn off the nitrogen generator; Step eight, remove the protective cover, turn on the laser, and the laser reflected from the ground sample surface enters the four-quadrant photodetector, at this time the position of the grinding surface on the Z axis displayed on the controller is the actual grinding amount, turn off the laser, and buckle the protective cover; Step nine, calculate the actual grinding efficiency, which is the ratio of the actual grinding amount obtained by laser measurement to the pre-set grinding amount, compare the actual grinding amount with the required grinding removal amount to obtain the grinding amount difference that needs to be compensated, formulate a second round of mirror surface grinding plan according to the actual grinding efficiency, compensate for the grinding amount difference, and repeat steps four to eight to accurately obtain the required grinding removal amount.

2. The method of using a high precision lapping machine based on laser measurement compensation according to claim 1, wherein, The laser emitted by the laser irradiates the sample grinding surface, is reflected from the sample surface into the four-quadrant photodetector, and generates an electrical signal output, and the position of the grinding surface in the Z direction is measured.

3. The method of using a high precision lapping machine based on laser measurement compensation of claim 1, wherein, The nitrogen blowing nozzle is located at the upper position of the grinding surface and is located in the protective cover when the protective cover is closed, and is movable left and right, and can blow the liquid and grinding dust film layer on the grinding surface.

4. The method of using a high precision lapping machine based on laser measurement compensation of claim 1, wherein, The pressure sensitive pad is located in the mounting groove, and when the protective cover is buckled, the pressure sensitive pad is compressed, the motor spindle can rotate at high speed for grinding, and at this time the laser cannot be started; when the protective cover is removed, the pressure sensitive pad cannot sense the pressure, the motor spindle cannot rotate, and the laser can be started for accurate measurement.

5. The method of using a high precision lapping machine based on laser measurement compensation according to claim 1, wherein, When the protective cover is buckled, the laser and the four-quadrant photodetector are located outside the protective cover and are not affected by the splashing of liquid and grinding dust.

6. The method of using a high precision lapping machine based on laser measurement compensation of claim 1, wherein, When the protective cover is buckled, the nitrogen blowing nozzle and the flow guide pipe are located in the protective cover and can move left and right along the guide rail and cooperate with each other, and the function is interlocked design, and only one mechanism of the nitrogen blowing nozzle and the flow guide pipe can work at a time.

7. The method of using a high precision lapping machine based on laser measurement compensation of claim 1, wherein, Relative to the sample grinding surface, the positions of the motor spindle, the nitrogen blowing nozzle, the flow guide pipe, the laser, the four-quadrant photodetector, the protective cover and the microscope are distributed and cooperate with each other, and the grinding surface can be nitrogen blown and laser measured under the condition that the motor spindle is set back.

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