Method for lossless scribing of bismuth telluride particles in ultra-miniature refrigeration device

Abstract

The invention discloses a lossless scribing method for bismuth telluride particles in an ultra-miniature refrigeration device. The lossless scribing method comprises the following steps: carrying out early-stage pretreatment on a bismuth telluride sheet; stably loading the pretreated bismuth telluride sheet on a carrier film; setting proper scribing parameters, and cutting the bismuth telluride sheet to form required ultra-small bismuth telluride particles; and taking down the particles from the loading film, cleaning, and drying to obtain the ultra-micro bismuth telluride particles. Due to the adoption of the technical scheme, lossless scribing of the bismuth telluride wafer with the submicron thickness can be achieved, micron-sized bismuth telluride particles needed by a Micro-TEC device are obtained, the yield is high, the flying belt rate is low, the quality is stable, the process is short, and industrial popularization is easy.

Description

Technical Field

[0001] The invention belongs to the field of thermoelectrics, and in particular relates to a method for non-destructive slicing of bismuth telluride particles in ultra-micro refrigeration devices. Background Art

[0002] Thermoelectric materials are a type of clean energy material that can directly realize the mutual conversion between thermal energy and electrical energy. Devices that work mainly based on thermoelectric materials are called thermoelectric devices.

[0003] When current is passed through a thermoelectric device (module), a temperature difference will be generated at both ends, which can be used directly for cooling. At this time, the thermoelectric device (module) is called a thermoelectric cooler (TEC), which has the advantages of small size, no noise, no pollution, high reliability, and temperature control accuracy of up to 0.1°C. It has huge application space in consumer electronics, communications, medical and other fields. The current research on the heat dissipation problem of electronic chips has reached a bottleneck, and micro-thermoelectric coolers (Micro-TEC) have great development potential in solving this problem.

[0004] Micro-TEC is an ultra-micro heat dissipation and cooling device made based on the thermoelectric Peltier effect. It is generally composed of dozens of ultra-micro grains. At present, its composition is generally selected from bismuth telluride-based thermoelectric materials with excellent performance at room temperature. It is a difficult problem to cut the brittle material bismuth telluride into the ultra-micro grains required by Micro-TEC, that is, less than 0.35mm in length and width and less than 0.4mm in height. When using a dicing machine to operate and process it, it is easy to cause material cracking and flying bands, resulting in unstable quality, low efficiency, low output rate and other problems. Summary of the invention

[0005] To solve the above problems, the present application provides a non-destructive slicing method for ultra-fine particles of brittle materials such as bismuth telluride. The method realizes the non-destructive slicing operation of ultra-fine grains of bismuth telluride-based materials through the pre-treatment of material slices, setting of slicing parameters and methods, and adjustment of material selection, thereby improving product stability and yield rate. According to the proposed scheme, the flying band rate is the number of flying bands divided by the number of samples on the final film, and the yield rate is the number of samples with complete edges divided by the final number of samples. After slicing according to the scheme, the flying band rate of the bismuth telluride sample is less than 0.3%, and the yield rate is greater than 99%.

[0006] The present application is mainly implemented by the following scheme: a method for non-destructive slicing of bismuth telluride particles in ultra-micro refrigeration devices, the method specifically comprising the following steps:

[0007] S1) pretreating the bismuth telluride flakes;

[0008] S2) firmly loading the bismuth telluride flakes pretreated in S1) on the carrier film;

[0009] S3) setting appropriate scribing parameters to cut the bismuth telluride sheet into desired ultra-fine bismuth telluride particles;

[0010] S4) removing the tiny bismuth telluride particles obtained in S3) from the carrier film, cleaning and drying them to obtain ultra-micro bismuth telluride particles.

[0011] Further, the pre-processing steps in S1) are:

[0012] S1.1) Use acetone, anhydrous ethanol and deionized water to ultrasonically clean for 5 to 15 minutes at an ultrasonic power of 20 kHz to 70 kHz. After cleaning, dry at a temperature of 45°C to 55°C in an argon atmosphere;

[0013] S1.2) Place the bismuth telluride sheet treated in S1.1) on a heating table at 80-100°C for 3 min, apply a layer of paraffin wax on one side, and then attach a laboratory glass slide to it, remove the whole piece and cool it down;

[0014] S1.3) The bismuth telluride sheet is ground in an alternating vertical grinding manner using sandpaper of 2000 mesh or above. When the scratches on the sample are in the same direction, the sample is ground in the vertical direction on the same plane. The thickness of the sample thinned in a single direction is 1% to 5% of the original sample thickness, and the overall thinning thickness does not exceed 15% of the original sample. After polishing, the bismuth telluride sheet with a thickness of 0.1 mm to 1 mm is obtained.

[0015] Furthermore, the specific process of polishing is: using a polishing cloth and a polishing agent to grind and polish the bismuth telluride sheet counterclockwise, and after the grinding and polishing is completed, the sample glass slide carrying the sample is placed on a heating table at 80-100°C and heated for 3 minutes. After the sample is separated from the slide, the sample is gently removed and placed in acetone for cleaning, so that the smoothness of the bismuth telluride sheet is obtained to be ≤Ra0.2.

[0016] Furthermore, the polishing cloth is velvet, silk, woolen cloth or cashmere; the polishing agent is a diamond aqueous solution suspension with a particle size of 0.1 μm to 3 μm.

[0017] Furthermore, the bismuth telluride sheet pasting step in S2) is: the sheet is pasted to the center of the carrier film, gently pressed from the four corners to the edges and then to the center, and moved to a heating table for heating, the temperature is set to 80°C to 140°C, and the heating time is 20min to 40min.

[0018] Furthermore, the carrier film is a blue film.

[0019] Further, the operation of determining the cutting range in S3) is: by selecting a long side x of the sample, taking the two outermost points on the side, determining the cutting position and the total cutting length in the y direction, and similarly rotating 0 to 90 degrees to determine the two outermost points on the other side y, determining the cutting position and the total cutting length in the x direction;

[0020] The dicing machine blade is a hard blade, the dicing machine blade height is -10 to 50 μm of the carrier film thickness, the dicing machine spindle speed is 20000 rpm to 35000 rpm, and the feed speed is 3 mm / s to 30 mm / s.

[0021] Furthermore, during the cutting process in S3), deionized water is used to cool the blade at a rate of 2.0 to 3.0 L / min.

[0022] Furthermore, the specific steps of S4) are: heating the carrier film, removing the ultra-fine bismuth telluride particles, and ultrasonically cleaning them with acetone, anhydrous ethanol, and deionized water for 5 to 15 minutes at a power of 20KHz to 70KHz. After cleaning, drying them in an argon atmosphere at a temperature of 45-55°C.

[0023] The beneficial effects achieved by the present invention are:

[0024] The method of the present invention adopts an alternating vertical grinding method to grind and polish bismuth telluride thin slices with a thickness of 0.1 mm to 1 mm, and simply but creatively places it on a glass slide for grinding and polishing, thereby solving the problem that the thin slice is difficult to hold and the grinding and polishing effect is poor. The single-direction grinding and thinning thickness is 1% to 5% of the original sample thickness, and the overall thinning thickness does not exceed 15% of the original sample, which can improve the surface finish of the thin slice, optimize its bonding with the carrier film, and does not damage the thin slice;

[0025] By adopting the method of the present invention to select the carrier film and pre-treat the sample carried by the carrier film, high-quality bonding of the bismuth telluride sheet and the carrier film can be achieved, and the occurrence of problems such as flying strips during the cutting process can be reduced;

[0026] By adopting the method of the present invention to slice brittle thin sheets such as bismuth telluride, within the range of its process parameters, efficiency and yield rate can be well balanced to obtain micron-sized bismuth telluride particles required for Micro-TEC devices, and the yield rate is high, the flying band rate is low, the quality is stable, the process is short, and it is easy to promote industrialization. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 The present invention is a flow chart of a method for non-destructive slicing of ultra-small bismuth telluride particles in Micro-TEC devices.

[0028] Figure 2 This is a simplified schematic diagram of dicing.

[0029] FIG. 3( a ) and FIG. 3( b ) are the dicing results without using the method of the present invention.

[0030] Figure 4 This is the dicing result of Example 1.

[0031] Figure 5 This is the dicing result of Example 2.

[0032] Figure 6 This is the dicing result of Example 3. DETAILED DESCRIPTION

[0033] The technical solution of the present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0034] like Figure 1 As shown, the present invention provides a method for non-destructive slicing of ultra-micro bismuth telluride particles in a Micro-TEC device, which comprises the following steps:

[0035] Step 1, cleaning the bismuth telluride sheet, and grinding and polishing the bismuth telluride sheet;

[0036] Step 2, loading the bismuth telluride flakes prepared in step 1 onto a carrier film after certain treatment;

[0037] Step 3, setting scribing parameters to cut the bismuth telluride sheet into required ultra-fine bismuth telluride particles;

[0038] Step 4: remove the particles from the carrier film, clean them, and dry them in an oven to obtain ultra-fine bismuth telluride particles.

[0039] The bismuth telluride flakes in this application refer to bismuth telluride-based doped or undoped bismuth telluride materials, which are obtained by multi-wire cutting with a thickness of 0.1 mm to 1 mm and have a certain shape. The surface roughness is improved by polishing to be less than or equal to Ra0.2, which is conducive to the loading of the carrier film, and the impurities carried on the flakes during multi-wire cutting can be removed by polishing and cleaning.

[0040] Preferably, the step 1 specifically includes the following operations:

[0041] 1.1, cleaning, the bismuth telluride sheet is placed in a beaker and ultrasonically cleaned with acetone, anhydrous ethanol, and deionized water respectively, and finally rinsed with deionized water in the same direction and then dried in an oven in an argon atmosphere.

[0042] 1.2. Grind the sample. Use an alternating vertical grinding method. Use sandpaper with a mesh size of 2000 or above to grind the bismuth telluride slice. When the scratches on the sample are in the same direction, you can continue grinding the sample in the vertical direction of the same plane. The thinning thickness of the sample in a single direction is 1% to 5% of the original sample thickness, and the overall thinning thickness does not exceed 15% of the original sample. According to the thickness of the bismuth telluride slice, flexibly select the initial mesh. Considering that the slice is thin and difficult to hold, it can be placed on a heating table at 80 to 100°C for 3 minutes, coated with a layer of paraffin on one side, and then affixed with a laboratory glass slide. Remove the whole thing and cool it down, and the bismuth telluride slice can be easily ground and thinned. Appropriate control of the thinning thickness is one of the important factors that affect the surface and thickness requirements while ensuring that the sample is not damaged or brittle. The heating temperature must be appropriate to ensure that the sample is not invariant while facilitating the experiment;

[0043] 1.3, polishing, polish the bismuth telluride slice that has been ground. The polishing cloth used can be made of velvet, silk, woolen cloth, cashmere, etc. The polishing agent used is a water-based diamond suspension with a particle size of 0.1μm to 3μm. Polish in a counterclockwise direction. After polishing, place the sample-carrying glass slide on a heating table at 80 to 100°C and heat for 3 minutes. After the sample is separated from the slide, gently remove the sample. After the operation is completed, repeat step 1.1 for cleaning.

[0044] Preferably, the carrier film is recommended to be a blue film with an adhesive peeling degree of 1000-3000Nm / 20mm and a thickness of 50-100μm, such as SPV224.

[0045] In the present application, a blue film is used as a thin carrier film, which can ensure that a certain adhesive force is provided to load the sample without damaging the blade during sample cutting, and can also make it convenient and quick to remove ultra-fine particles after cutting.

[0046] Preferably, the step 2 specifically includes the following operations:

[0047] 2.1: Paste the bismuth telluride sheet on the center of the carrier film covering the positioning plate and press it gently to stick it tightly;

[0048] 2.2: Move the carrier film loaded with the sample to the heating table for heating, with the sample facing upwards, so that the sample and the carrier film fit tightly. If this step is not taken, the sample flying rate will change.

[0049] Preferably, the heating temperature of the carrier film is 80℃~140℃. Heating temperatures outside this range will affect the adhesion between the sample and the carrier film. Too high a temperature will affect the performance of the carrier film. Figure 2 shown.

[0050] Preferably, the heating time of the carrier film is 20 min to 40 min.

[0051] Preferably, a suitable model is selected according to the size of the bismuth telluride particles to be cut.

[0052] Preferably, the step three specifically includes the following operations:

[0053] 3.1: The precision dicing machine performs preparation work such as sharpening the blade, measuring the height, and determining the cutting range;

[0054] 3.2: Set the appropriate spindle speed, blade height and travel speed;

[0055] 3.3: Set the cutting plan and start cutting to obtain ultra-fine bismuth telluride particles.

[0056] Preferably, according to the size of the cut bismuth telluride particles of 0.20mm to 0.60mm, the spindle speed of the dicing machine can be set to 20000rpm to 35000rpm, and the feed speed can be set to 3mm / s to 30mm / s. Too fast or too slow feed speed will have a negative impact on the cutting yield and flying tape rate.

[0057] Preferably, the operation of determining the cutting range in step three is mainly performed by selecting one long side x of the sample, taking the two outermost points on the side, determining the cutting position and the total cutting length in the y direction, and similarly rotating 0 to 90 degrees to determine the two outermost points on the other side y, determining the cutting position and the total cutting length in the x direction, and finally setting the feed spacing.

[0058] Preferably, the dicing machine blade is a hard blade. The appropriate model is selected according to the size of the bismuth telluride particles to be cut. Blades of non-corresponding materials will affect the sample's yield and flying rate.

[0059] Preferably, the height of the dicing machine blade is -10 to 50 μm of the substrate film thickness.

[0060] Preferably, a dicing machine's feed speed that is too fast or too slow will have a negative impact on the cutting yield and flying tape rate.

[0061] Preferably, the deionized water is used to cool the blade at a rate of 2.0 to 3.0 L / min. Too much water flow will affect the cutting accuracy of the blade and aggravate the flying of the sample.

[0062] Preferably, by adjusting the interval step length of each feed, and after cutting in one direction, the working disk is rotated 0° to 90° to complete the cutting of bismuth telluride particles of different shapes, such as rectangles.

[0063] Preferably, the step 4 specifically includes the following operations:

[0064] 4.1: Move the carrier film carrying bismuth telluride particles after slicing to a heating table for heating, and remove the bismuth telluride particles after softening;

[0065] 4.2: Move the removed bismuth telluride particles to a beaker, add anhydrous ethanol and ultrasonically clean them before taking them out. In this process, the residual colloid in the carrier film and other impurities such as oil stains brought by the cutting process can be better removed;

[0066] 4.3: Rinse the bismuth telluride particles with deionized water and dry them.

[0067] Preferably, the ultrasonic cleaning power of steps 1 and 4 is 20KHz to 70KHz, and the corresponding cleaning time is 30min to 10min.

[0068] Preferably, the deionized water rinsing time in steps one and four is 5 minutes to 15 minutes.

[0069] Example 1

[0070] 1) Clean the 30×30×0.35 mm bismuth telluride sheet. The specific cleaning process is: use acetone, anhydrous ethanol, and deionized water for ultrasonic cleaning for 10 minutes in sequence, with an ultrasonic power of 50 KHz. After cleaning, dry it in an oven in an argon atmosphere at a temperature of 50°C.

[0071] 2) Use the alternating vertical grinding method, select 5000 mesh sandpaper, and grind the bismuth telluride slice. When the scratches on the sample are in the same direction, you can switch to the vertical direction of the same plane and continue grinding. Alternate directions 3 times, and reduce the thickness by 3% each time.

[0072] 3) Polishing the bismuth telluride flakes by grinding the sample, the polishing cloth used is made of real velvet, the polishing agent used is a water-based diamond suspension, the particle size is 0.5 μm, and the polishing is counterclockwise. After polishing, cleaning and drying are performed as in step 1).

[0073] 4) Paste the dried sheet to the center of the 70μm thick blue film, press it tightly, move it to the heating table for heating, set the temperature to 120℃, and the heating time is 30min.

[0074] 5) The height of the dicing machine blade is 50μm.

[0075] 6) The blade is a hard blade. Depending on the size of the bismuth telluride particles being cut, the model can be SC-15-E-50-DD.

[0076] 7) Set the spindle speed of the dicing machine to 20000rpm and the feed speed to 10mm / s.

[0077] 8) Cool the blade with deionized water at a rate of 2.0 to 3.0 L / min.

[0078] 9) To determine the cutting range, select the long side x of the sample, take the two outermost points on the side, determine the cutting position and total cutting length in the y direction, and similarly rotate 0 to 90 degrees to determine the two outermost points on the other side y, determine the cutting position and total cutting length in the x direction, set the feed spacing in the x and y directions to 0.35 mm, and start cutting. Figure 4 shown.

[0079] 10) After the cutting is completed, the carrier plate is removed, the blue film is heated, and the ultra-fine bismuth telluride particles are removed. Acetone, anhydrous ethanol, and deionized water are used for ultrasonic cleaning for 10 minutes in sequence at a power of 50KHz. After the cleaning is completed, the particles are dried in an oven under argon protection at a temperature of 50°C to obtain ultra-fine bismuth telluride particles. Sampling inspection shows that the yield rate is greater than 99.2% and the flying tape rate is less than 0.01%.

[0080] Example 2

[0081] 1) Clean the 30×30×0.4 mm bismuth telluride sheet. The specific cleaning process is: use acetone, anhydrous ethanol, and deionized water for ultrasonic cleaning for 10 minutes in sequence, with an ultrasonic power of 70 KHz. After cleaning, dry it in an oven in an argon atmosphere at a temperature of 50°C.

[0082] 2) Use the alternating vertical grinding method, select 5000 mesh sandpaper, and grind the bismuth telluride slice. When the scratches on the sample are in the same direction, you can switch to the vertical direction of the same plane and continue grinding. Alternate directions 4 times, and thin the thickness by 3% each time.

[0083] 3) Polishing the bismuth telluride flakes by grinding the sample, the polishing cloth used is made of real velvet, the polishing agent used is a water-based diamond suspension, the particle size is 0.5 μm, and the polishing is counterclockwise. After polishing, cleaning and drying are performed as in step 1).

[0084] 4) Paste the dried sheet to the center of the 70μm thick blue film, press it tightly, move it to the heating table for heating, set the temperature to 120℃, and the heating time is 30min.

[0085] 5) The height of the dicing machine blade is 40μm.

[0086] 6) The dicing machine blade is a hard blade. Depending on the size of the bismuth telluride particles being cut, the model can be SC-15-E-50-DD.

[0087] 7) Set the spindle speed of the dicing machine to 20000rpm and the feed speed to 15mm / s.

[0088] 8) Cool the blade with deionized water at a rate of 2.0 to 3.0 L / min.

[0089] 9) To determine the cutting range, select the long side x of the sample, take the two outermost points on the side, determine the cutting position and total cutting length in the y direction, and similarly rotate 0 to 90 degrees to determine the two outermost points on the other side y, determine the cutting position and total cutting length in the x direction, set the feed spacing in the x and y directions to 0.35 mm, and start cutting. Figure 5 shown.

[0090] 10) After the cutting is completed, the carrier plate is removed, the blue film is heated, the ultra-fine bismuth telluride particles are removed, and ultrasonic cleaning is performed with acetone, anhydrous ethanol, and deionized water for 10 minutes at a power of 50KHz. After the cleaning is completed, the particles are dried in an oven under argon protection at a temperature of 50°C to obtain ultra-fine bismuth telluride particles. Sampling inspection shows that the yield rate is greater than 99.3% and the flying tape rate is less than 0.01%.

[0091] Example 3

[0092] 1) Clean the 30×30×0.25 mm bismuth telluride sheet. The specific cleaning process is: use acetone, anhydrous ethanol, and deionized water for ultrasonic cleaning for 15 minutes in sequence, with an ultrasonic power of 30 KHz. After cleaning, dry it in an oven in an argon atmosphere at a temperature of 50°C.

[0093] 2) Use the alternating vertical grinding method, select 5000 mesh sandpaper, and grind the bismuth telluride slice. When the sample scratches are in the same direction, you can switch to the vertical direction of the same plane and continue grinding. Alternate directions twice, and thin the thickness by 5% each time.

[0094] 3) Polishing the bismuth telluride flakes by grinding the sample, the polishing cloth used is made of real velvet, the polishing agent used is a water-based diamond suspension, the particle size is 0.1 μm, and the polishing is counterclockwise. After polishing, cleaning and drying are performed as in step 1).

[0095] 4) Paste the dried sheet to the center of the 70μm thick blue film, press it tightly, move it to the heating table for heating, set the temperature to 100℃, and the heating time is 35min.

[0096] 5) The height of the dicing machine blade is 60μm.

[0097] 6) The blade is a hard blade. Depending on the size of the bismuth telluride particles being cut, the model can be SC-15-E-50-DD.

[0098] 7) Set the spindle speed of the dicing machine to 20000rpm and the feed speed to 5mm / s.

[0099] 8) Cool the blade with deionized water at a rate of 2.0 to 3.0 L / min.

[0100] 9) To determine the cutting range, select the long side x of the sample, take the two outermost points on the side, determine the cutting position and total cutting length in the y direction, and similarly rotate 0 to 90 degrees to determine the two outermost points on the other side y, determine the cutting position and total cutting length in the x direction, set the feed spacing in the x and y directions to 0.25 mm, and start cutting. Figure 6 shown.

[0101] 10) After the cutting is completed, the carrier plate is removed, the blue film is heated, and the ultra-fine bismuth telluride particles are removed. Acetone, anhydrous ethanol, and deionized water are used for ultrasonic cleaning for 10 minutes in sequence at a power of 50KHz. After the cleaning is completed, the particles are dried in an oven under argon protection at a temperature of 50°C to obtain ultra-fine bismuth telluride particles. Sampling inspection shows that the yield rate is greater than 99% and the flying tape rate is less than 0.1%.

[0102] Matters not covered by the present invention are known technologies.

[0103] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for non-destructive slicing of bismuth telluride particles in ultra-micro refrigeration devices, characterized in that: The method specifically comprises the following steps: S1) pretreating the bismuth telluride flakes; S2) firmly loading the bismuth telluride flakes pretreated in S1) on the carrier film; S3) setting appropriate scribing parameters to cut the bismuth telluride sheet into desired ultra-fine bismuth telluride particles; S4) removing the tiny bismuth telluride particles obtained in S3) from the carrier film, cleaning and drying them to obtain ultra-micro bismuth telluride particles.

2. The method according to claim 1, characterized in that The pre-processing steps in S1) are: S1.1) ultrasonic cleaning was performed using acetone, anhydrous ethanol and deionized water for 5 to 15 minutes at an ultrasonic power of 20 kHz to 70 kHz. After cleaning, the cleaning was performed at a temperature of 45°C to 55°C and an argon atmosphere for drying; S1.2) Place the bismuth telluride sheet treated in S1.1) on a heating table at 80-100°C for 3 min, apply a layer of paraffin wax on one side, and then attach a laboratory glass slide to it, remove the whole piece and cool it; S1.3) The bismuth telluride sheet is ground in an alternating vertical grinding manner using sandpaper of 2000 mesh or above. When the scratches on the sample are in the same direction, the sample is ground in the vertical direction on the same plane. The thickness of the sample thinned in a single direction is 1% to 5% of the original sample thickness, and the overall thinning thickness does not exceed 15% of the original sample. After polishing, the bismuth telluride sheet with a thickness of 0.1 mm to 1 mm is obtained.

3. The method according to claim 2, characterized in that The specific polishing process is as follows: the bismuth telluride sheet is counterclockwise ground and polished with a polishing cloth and a polishing agent, and after the grinding and polishing is completed, the sample-carrying glass sheet is placed on a heating table at 80 to 100° C. and heated for 3 minutes, and after the sample is separated from the sample sheet, the sample is gently removed and placed in acetone for cleaning, so that the smoothness of the bismuth telluride sheet is obtained to be ≤Ra0.

2.

4. The method according to claim 3, characterized in that The polishing cloth is real velvet, silk, woolen cloth or cashmere; the polishing agent is a diamond aqueous solution suspension with a particle size of 0.1 μm to 3 μm.

5. The method according to claim 1, characterized in that: The bismuth telluride sheet pasting step in S2) is as follows: the sheet is pasted to the center of the carrier film, gently pressed from the four corners to the edges and then to the center, and moved to a heating table for heating, the temperature is set to 80°C to 140°C, and the heating time is 20min to 40min.

6. The method according to claim 5, characterized in that The carrier film is a blue film.

7. The method according to claim 1, characterized in that The operation of determining the cutting range in S3) is as follows: by selecting a long side x of the sample, taking the two outermost points on the side, determining the cutting position and the total cutting length in the y direction, and similarly rotating 0 to 90 degrees to determine the two outermost points on the other side y, determining the cutting position and the total cutting length in the x direction; The dicing machine blade is a hard blade, the dicing machine blade height is -10 to 50 μm of the carrier film thickness, the dicing machine spindle speed is 20000 rpm to 35000 rpm, and the feed speed is 3 mm / s to 30 mm / s.

8. The method according to claim 7, characterized in that During the cutting process in S3), deionized water is used to cool the blade at a rate of 2.0 to 3.0 L / min.

9. The method according to claim 1, characterized in that: The specific steps of S4) are: heating the carrier film, removing the ultra-fine bismuth telluride particles, and ultrasonically cleaning them with acetone, anhydrous ethanol, and deionized water for 5 to 15 minutes at a power of 20KHz to 70KHz. After cleaning, drying them in an argon atmosphere at a temperature of 45-55°C.

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