A diamond laser slicing method and system for heat sink material and a diamond heat diffusion sheet

Abstract

The application provides a diamond laser slicing method and system for heat sink materials and a diamond heat diffusion sheet, and the method comprises the following steps: S1, detecting a diamond blank to be sliced and determining a target slicing surface position; S2, forming an edge release slot around the target slicing surface position; S3, using a first laser beam to perform buried layer scanning on the inside of the diamond blank to be sliced along the target slicing surface position, forming a continuous or quasi-continuous buried layer modification zone; S4, using a second laser beam to perform auxiliary irradiation on the edge release slot, so that the buried layer modification zone and the edge release slot are connected and separated to form a controllable separation interface; and S5, applying low load separation to the diamond blank, so that the diamond blank is separated into a heat sink sheet and a mother body residual material along the controllable separation interface. The application realizes slicing through internal buried layer modification and subsequent low load separation, instead of relying on mechanical grinding of the whole thickness, so that the slicing loss is significantly lower than that of traditional wire cutting.

Description

Technical Field

[0001] This invention relates to the field of diamond laser slicing technology, and particularly to a diamond laser slicing method, system, and diamond heat diffusion sheet for heat sink materials. Background Technology

[0002] With the rapid expansion of AI training, inference, and high-performance computing applications, the heat flux density of GPUs, HBMs, Chiplet packages, and high-density server nodes continues to rise. Chip power consumption, localized hotspots, and insufficient heat dissipation efficiency have become significant constraints for further improving computing power density and system energy efficiency. Public industry data shows that innovation in heat sink materials is becoming one of the important technological paths to solve this problem, and diamond, due to its extremely high thermal conductivity and excellent electrical insulation properties, is extending from high-end optoelectronic and radio frequency applications to high-performance chip thermal management.

[0003] Public data shows that synthetic diamond has a significantly higher thermal conductivity than traditional materials such as copper, silicon, and silicon carbide. For high heat flux density chips, diamond heat sinks not only "conduct heat faster," but more importantly, they can reduce local junction temperature, lower package thermal resistance, and create conditions for higher frequency and higher power density operation. Therefore, diamond heat sink materials have been considered an important candidate solution for heat dissipation in next-generation high-performance chips and servers. However, the industrialization of diamond into the heat sink field has long been constrained by three types of problems: first, the difficulty in large-size and high-yield fabrication; second, the high processing cost; and third, as an extremely hard and brittle material, its cutting, thinning, and surface finishing are extremely difficult.

[0004] Traditional cutting processes for diamond materials have the following drawbacks: 1) Low mechanical removal efficiency, long cutting time, large kerf loss, and severe tool wear, resulting in poor cutting consistency and process stability, making it difficult to meet the needs of mass production of heat sink materials; 2) Laser direct ablation cutting methods have relatively simple equipment, but are often accompanied by a large heat-affected zone and insufficient edge quality; 3) Local processing methods using laser-induced graphitization or phase transformation can form non-diamond layers in diamond, but are mostly used for local channels, microstructures, or thin-layer peeling; 4) Local processing methods using laser-induced graphitization or phase transformation can form non-diamond layers in diamond, but are mostly used for local channels, microstructures, or thin-layer peeling.

[0005] While existing laser processing methods for diamond have proven capable of cutting, grooving, cleaving, or localized ablation, they are primarily focused on jewelry, cutting tools, optical components, quantum devices, or localized microstructure processing. They cannot directly meet the comprehensive requirements of low loss, low damage, thickness uniformity, and subsequent bonding interface quality in the mass production of heat sink sheets. Existing laser technologies suffer from the following shortcomings: 1) Many schemes emphasize direct ablation, resulting in a large heat-affected zone and significant edge taper and redeposition issues; 2) Many schemes lack matching designs for differences in diamond crystal orientation, texture, cleavage behavior, and graphitization threshold, leading to insufficient slice consistency; 3) They easily introduce deep surface and subsurface damage, increasing the cost of subsequent polishing and interface preparation; 4) There is a lack of a complete process solution specifically designed for heat sink sheet manufacturing that balances high efficiency, low loss, low subsurface damage, and large-size adaptability.

[0006] Therefore, there is an urgent need to propose a new method for diamond laser slicing suitable for heat sink material preparation, to replace the shortcomings of traditional wire cutting in terms of efficiency, loss and yield, and to enable the prepared diamond heat diffusion sheet to meet the requirements of chip heat sink, packaged heat diffusion sheet and composite thermal management components for thickness, flatness, interface cleanliness and thermal conductivity. Summary of the Invention

[0007] The purpose of this invention is to provide a method, system, and diamond thermal diffusion sheet for diamond laser slicing of heat sink materials, in order to solve the problems of low efficiency, large kerf loss, high processing cost, severe tool wear, and large subsurface damage in existing mechanical cutting, while also solving the problems of many random cracks, poor thickness uniformity, and difficulty in subsequent interface preparation when laser processing diamond.

[0008] This invention focuses on the manufacturing goals of diamond heat sinks and constructs a complete process chain consisting of crystal orientation / texture identification, internal buried layer modification, edge crack release control, low-load separation, removal of residual non-diamond layers, and double-sided finishing. The main features of this solution are: 1. Determine the scanning direction and energy deposition strategy based on single-crystal orientation or polycrystalline texture; 2. First, establish a controllable separation interface inside the material, rather than directly cutting through the entire thickness; 3. The modified layer is connected by an edge release groove and a second laser beam, allowing the crack to propagate under controlled conditions; 4. The removal of the residual non-diamond layer after separation and the preparation of the heat sink interface are incorporated into the same technical solution; 5. The target product is a diamond heat diffusion sheet that meets the requirements of heat sink applications, rather than a diamond machining part in the general sense.

[0009] Specifically, the diamond laser slicing method for heat sink materials provided by this invention includes the following steps: S1. Inspect the diamond blank to be sliced ​​and determine the location of the target slicing surface; S2. An edge release groove is formed around the target slice surface. S3. The first laser beam is used to scan the interior of the diamond billet to be sliced ​​along the target slice surface to form a continuous or quasi-continuous embedded layer modification zone. S4. A second laser beam is used to irradiate the edge crack release groove, so that the buried layer modification zone and the edge crack release groove are connected and a controllable separation interface is formed. S5. Apply a low-load separation to the diamond billet, causing it to separate into a heat sink sheet and residual parent material along the controllable separation interface. The low-load separation includes one or more of the following: tension, bending, differential pressure adsorption, thermal stress, or ultrasonic vibration.

[0010] The target slice location is the theoretically predetermined imaginary plane on which you wish to bisect the diamond billet. For example, based on the required heat sink thickness (e.g., 300 μm), a virtual geometric plane is predetermined inside the billet. The embedded layer modification zone is a physical modification layer (containing microcracks, graphitized phases, etc.) formed internally by the first laser beam, which coincides with the "target slice location." The first laser beam is precisely focused on this virtual plane for scanning, visualizing the theoretical target as a thin-layer damage zone (approximately 2-40 μm thick) inside.

[0011] The edge release groove is a physical groove machined around the area to be sliced, located on the surface of the billet (top or bottom), extending downwards, with its bottom reaching or slightly penetrating the depth of the buried modification zone. It surrounds the area to be sliced ​​in the top view (essentially drawing an "outer frame"), serving as a trigger boundary for separation, preventing crack propagation to non-target areas, and providing stress concentration points for subsequent external forces. The controllable separation interface is a complete, continuous fracture guiding surface formed after being connected by the second laser beam. It is composed of the "buried modification zone" and the "edge release groove," which are perpendicularly intersecting and connected. At this point, a complete weak zone, open to the outside, has formed inside the billet along the target slicing surface, ready to be completely separated along this interface upon the application of external force.

[0012] For diamond / SiC composite preforms used in liquid-cooled cold plates or composite thermal diffusers, the buried layer modification and crack release slicing of the present invention are performed only on one side of the diamond layer to obtain a diamond surface layer of a predetermined thickness, and then it is subsequently composited with SiC, metal or ceramic substrates.

[0013] Preferably, the thickness of the diamond blank to be sliced ​​is measured, and the position of the target slicing surface is determined based on the thickness of the target heat sink sheet. Preferably, S1 further includes: measuring the thickness, flatness, warpage, surface roughness, and thermal conductivity of the diamond blank to be processed; for single-crystal diamond, further identifying its surface crystal orientation, cleavage plane projection direction, and deflection angle; for polycrystalline CVD diamond, obtaining its texture direction, grain size distribution, and grain boundary density distribution.

[0014] Preferably, the depth of the edge release groove is 20-300 μm and the groove width is 10-80 μm. One or more rings of edge release grooves are formed around the area to be sliced ​​to define the subsequent separation boundary and reduce the probability of random cracks propagating into non-target areas.

[0015] Preferably, the depth of the embedded modified layer from the surface of the diamond billet to be sliced ​​is 30-1500 μm, and the thickness of the modified layer is 2-40 μm. A first laser beam is used to perform surface scanning, layer scanning, or partition scanning at a predetermined depth from the billet surface to form a continuous or quasi-continuous embedded modified layer inside the diamond. The buried layer modification zone includes graphitized phase, amorphous carbon phase, micropores, microcracks or combinations thereof; The scanning direction is matched and controlled according to the single crystal cleavage direction or the polycrystalline texture direction.

[0016] Preferably, the first laser beam is a femtosecond or picosecond laser with a wavelength of 343nm, 515nm, 532nm, 1030nm or 1064nm and a pulse width of 100fs-20ps; the first laser beam adopts a pulse train mode, each train contains 2-20 sub-pulses, and the energy of a single train is 1-50 μJ.

[0017] Preferably, the second laser beam is a nanosecond laser or a continuous laser with a wavelength of 355nm, 532nm, 808nm, 980nm, or 1064nm. The second laser beam is used to perform auxiliary heating, auxiliary graphitization, auxiliary crack connection, or stress-induced treatment along the edge crack release groove, the end of the buried layer, and / or the predetermined connection area, so that a controllable separation interface is gradually formed in the modified buried layer area.

[0018] Preferably, the diamond blank is a single-crystal diamond, and the main scanning direction of the first laser beam is aligned with the single-crystal diamond. <110> The included angle of the projection direction is 10°-60°; the diamond billet is polycrystalline CVD diamond, and different laser energies, line spacings or scanning speeds are set according to the texture partition to achieve regional compensation scanning. The single-string energy of the coarse grain region is 3-15μJ, and the single-string energy of the high grain boundary density region is 5-25μJ.

[0019] Preferably, the diamond laser slicing method further includes: S6, removing the non-diamond residual layer on the surface of the heat sink sheet and performing double-sided finishing. Double-sided finishing includes: performing double-sided thinning, ultra-precision grinding, CMP polishing, ion beam assisted finishing or a combination thereof on the heat sink sheet to obtain a diamond heat diffusion sheet that meets the requirements for thickness tolerance, TTV, surface roughness and interface cleanliness.

[0020] Preferably, the removal method of the non-diamond residual layer includes one or more of oxygen plasma treatment, low-temperature oxidation, ozone treatment, and electrochemical removal; the removal depth is 0.1 to 20 μm, removing the residual graphitized layer, amorphous carbon layer, and resolidified residual layer.

[0021] Preferably, the depth of removal of the residual non-diamond layer is 0.1-20 μm, and the thickness of the heat sink sheet is preferably 50-1000 μm.

[0022] The present invention also provides a system for implementing the above-described diamond laser slicing method, comprising: The detection unit is used to detect the diamond blank to be sliced ​​and determine the position of the target slicing surface; Edge crack release processing unit, used to form edge crack release grooves around the area to be sliced; The first laser processing unit is used to perform embedded layer scanning along the target slicing surface to form a continuous or quasi-continuous embedded layer modification zone inside the diamond billet to be sliced. The second laser processing unit is used to assist in irradiating the edge crack release groove, so that the buried layer modification zone and the edge crack release groove are connected and form a controllable separation interface. A low-load separation unit is used to apply a low-load separation to the diamond billet, causing it to separate into heat sink sheet and mother body residue along the controllable separation interface.

[0023] The present invention also provides a diamond thermal diffusion sheet, which is prepared by the above method.

[0024] The present invention has the following beneficial effects: This invention achieves slicing through internal embedded layer modification and subsequent low-load separation, rather than relying on full-thickness mechanical grinding. Therefore, the kerf loss is significantly lower than traditional wire cutting, making it particularly suitable for high-value diamond heat sink materials. This invention establishes a controllable internal separation interface through second laser beam assisted irradiation, combined with assisted fracture release for rapid separation, achieving an overall efficiency several times that of traditional wire cutting, preferably more than five times. Localized laser energy deposition facilitates the formation of a narrow and controllable modification band internally. Combined with residual non-diamond layer removal and double-sided finishing, the thickness of the subsurface damage layer can be significantly reduced.

[0025] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description and the accompanying drawings.

[0026] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0027] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings: Figure 1 This is a schematic flowchart illustrating a diamond laser slicing method for heat sink materials, as proposed in this invention. Detailed Implementation

[0028] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0029] like Figure 1 As shown, the present invention provides a diamond laser slicing method for heat sink materials, which includes the following steps: S1. Inspect the diamond blank to be sliced ​​and determine the location of the target slicing surface; S2. An edge release groove is formed around the target slice surface. S3. The first laser beam is used to scan the interior of the diamond billet to be sliced ​​along the target slice surface to form a continuous or quasi-continuous embedded layer modification zone. S4. A second laser beam is used to irradiate the edge crack release groove, so that the buried layer modification zone and the edge crack release groove are connected and a controllable separation interface is formed. S5. Apply a low load to the diamond billet to separate it into heat sink sheet and mother body residue along the controllable separation interface.

[0030] The above method employs a composite separation structure of "edge crack release groove + internal buried layer modification zone + second laser beam connection" rather than simple thick-layer ablation or single modification; it incorporates the removal of the non-diamond residual layer after separation and the control of the cleanliness of the heat sink interface into the same technical solution; applying the above process to heat sink manufacturing scenarios emphasizes thickness uniformity, TTV, low-damage layer, and the quality of subsequent bonding interfaces; it covers the application of diamond layer slicing in single-crystal, polycrystalline CVD, and composite heat sink preforms.

[0031] The present invention will be further described below with reference to embodiments. Example 1

[0032] A single-crystal CVD diamond blank with a thickness of 1.2 mm and a size of 20 mm × 20 mm was selected as the raw material, and the target heat sink thickness was 300 μm.

[0033] First, X-ray orientation and polarized Raman spectroscopy were used to identify the principal crystal orientation of its surface as (100), and then determined... <110> Projection direction.

[0034] A 355 nm ultraviolet picosecond laser was used to prefabricate edge crack release grooves with a width of 30 μm and a depth of 80 μm around the workpiece.

[0035] Then, a 515 nm femtosecond pulse train laser was used to perform buried layer scanning at a distance of 300 μm from the upper surface. The pulse width was 400 fs, the repetition frequency was 500 kHz, each train consisted of 4 sub-pulses, the energy of a single train was 8 μJ, the line spacing was 4 μm, and the scanning speed was 80 mm / s. The main scanning direction was parallel to... <110> The angle between the projection directions is 30°.

[0036] After the buried layer scanning is completed, a 1064 nm nanosecond laser is used to perform four auxiliary interconnection scans along the edge crack release groove to connect the microcracks at the end of the buried layer with the edge groove.

[0037] Then, a controlled bending load is applied to complete the separation of the heat sink sheet.

[0038] After separation, the residual graphitization layer was removed by oxygen plasma treatment for 8 min, and then subjected to double-sided CMP treatment to obtain a diamond heat sink sheet with a thickness of 300±8 μm, TTV≤12 μm, and surface roughness Ra≤20 nm.

[0039] Example 2

[0040] A polycrystalline MPCVD diamond substrate with a thickness of 2.0 mm and a size of 50 mm × 50 mm was selected, with a target substrate thickness of 500 μm.

[0041] First, perform EBSD texture statistics and Raman mapping on the plate to identify grain coarsening regions and high grain boundary density regions.

[0042] Different energy compensation values ​​were set for different regions: 6 μJ per pulse in the coarse grain region and 8 μJ per pulse in the high grain boundary density region; a 1030 nm femtosecond laser was used uniformly with a pulse width of 700 fs, a repetition frequency of 1 MHz, and a scanning speed of 120 mm / s.

[0043] To reduce warping, a double-layer modified material zone was formed by symmetrical mirror scanning of the upper and lower surfaces, with each layer having a thickness of approximately 12 μm.

[0044] Then, an 808 nm continuous laser was used for edge thermal-induced release cracking, which was combined with vacuum adsorption differential pressure to achieve separation.

[0045] After separation, the graphitized layer was removed by low-temperature oxidation treatment at 400℃, followed by double-sided fine grinding and polishing to obtain a heat sink sheet with a thickness of 500±12 μm, TTV≤12 μm, and surface roughness Ra≤20 nm.

[0046] Example 3

[0047] A single-crystal CVD diamond blank with a thickness of 0.8 mm and a size of 10 mm × 10 mm was selected as the raw material, and the target heat sink thickness was 100 μm.

[0048] First, X-ray orientation and polarized Raman spectroscopy were used to identify the principal crystal orientation of its surface as (100), and then determined... <110> Projection direction.

[0049] A 355 nm ultraviolet picosecond laser was used to pre-fabricate edge crack release grooves 10 μm wide and 20 μm deep around the workpiece.

[0050] Then, a 343 nm femtosecond pulse train laser was used to perform buried layer scanning at a distance of 100 μm from the upper surface. The pulse width was 100 fs, the repetition frequency was 5 MHz, each train consisted of 2 sub-pulses, the energy of a single train was 1 μJ, the line spacing was 1 μm, the scanning speed was 50 mm / s, and the main scanning direction was parallel to... <110> The angle between the projection directions is 10°.

[0051] After the buried layer scanning is completed, a 355 nm nanosecond laser is used to perform one auxiliary connection scan along the edge crack release groove to connect the microcrack at the end of the buried layer with the edge groove.

[0052] Subsequently, differential pressure adsorption separation (pressure difference ΔP = 0.1 MPa) was applied to complete the separation of the heat sink sheet.

[0053] After separation, the residual graphitization layer was removed by ozone treatment, and then double-sided CMP treatment was performed to obtain a diamond heat sink sheet with a thickness of 100±5 μm, TTV≤10 μm, and surface roughness Ra≤10 nm.

[0054] Example 4

[0055] A single-crystal CVD diamond blank with a thickness of 3.0 mm and a size of 80 mm × 80 mm was selected as the raw material, and the target heat sink thickness was 1000 μm.

[0056] First, X-ray orientation and polarized Raman spectroscopy were used to identify the principal crystal orientation of its surface as (100), and then determined... <110> Projection direction.

[0057] A 355 nm ultraviolet picosecond laser was used to prefabricate edge crack release grooves with a width of 80 μm and a depth of 300 μm around the workpiece.

[0058] Then, a 1064 nm femtosecond pulse train laser was used to perform buried layer scanning at a distance of 1000 μm from the upper surface. The pulse width was 20 ps, ​​the repetition frequency was 10 kHz, each train consisted of 20 sub-pulses, the energy of a single train was 50 μJ, the line spacing was 20 μm, the scanning speed was 500 mm / s, and the main scanning direction was... <110> The angle between the projection directions is 60°.

[0059] After the buried layer scanning is completed, a 1064 nm nanosecond laser is used to perform 10 auxiliary interconnection scans along the edge crack release groove to connect the microcracks at the end of the buried layer with the edge groove.

[0060] Subsequently, a bending load was applied for separation (bending radius R = 500 mm) to complete the separation of the heat sink sheet.

[0061] After separation, the residual graphitization layer was removed by oxygen plasma treatment for 20 min, and then subjected to double-sided CMP treatment to obtain a diamond heat sink sheet with a thickness of 1000±15 μm, TTV≤15 μm, and surface roughness Ra≤25 nm.

[0062] Example 5

[0063] A single-crystal CVD diamond blank with a thickness of 1.5 mm and a size of 30 mm × 30 mm was selected as the raw material, and the target heat sink thickness was 400 μm.

[0064] First, X-ray orientation and polarized Raman spectroscopy were used to identify the principal crystal orientation of its surface as (100), and then the orientation was determined. <110> Determine the projection direction and confirm that there is a 5° deflection angle on the surface.

[0065] A 355 nm ultraviolet picosecond laser was used to prefabricate edge crack release grooves with a width of 50 μm and a depth of 150 μm around the workpiece.

[0066] Then, a 532 nm femtosecond pulse train laser was used to perform buried layer scanning at a distance of 400 μm from the upper surface. The pulse width was 800 fs, the repetition frequency was 200 kHz, each train consisted of 10 sub-pulses, the energy of a single train was 25 μJ, the line spacing was 10 μm, the scanning speed was 200 mm / s, and the main scanning direction was parallel to... <110> The angle between the projection directions is 45°.

[0067] To verify the feasibility of different separation methods, after the buried layer scanning was completed, a 1064 nm nanosecond laser was used to perform three auxiliary interconnection scans along the edge crack release groove to connect the microcracks at the end of the buried layer with the edge groove.

[0068] Subsequently, thermal stress separation is applied (a temperature difference of 110°C is applied to the billet), and the interface is separated by thermal stress generated by the difference in thermal expansion coefficients.

[0069] After separation, the residual graphitization layer was removed by oxygen plasma treatment for 12 min, followed by double-sided CMP treatment to obtain a diamond heat sink sheet with a thickness of 400±10 μm, TTV≤12 μm, and surface roughness Ra≤15 nm.

[0070] Example 6

[0071] Polycrystalline MPCVD diamond plates with a thickness of 2.5 mm and a size of 60 mm × 60 mm were selected as raw materials, with a target sheet thickness of 800 μm.

[0072] First, EBSD texture statistics and Raman mapping are performed on the plate to identify grain coarsening regions, high grain boundary density regions, and transition regions with large differences in texture orientation.

[0073] Differential energy compensation is then applied to different regions: 3 μJ per string in the fine-grained region, 15 μJ per string in the coarse-grained region, 25 μJ per string in the high grain boundary density region, and 10 μJ per string in the transition region.

[0074] A 1030 nm femtosecond laser was used uniformly, with a pulse width of 500 fs, a repetition rate of 800 kHz, and a scanning speed of 80 mm / s.

[0075] To reduce warping, a double-layer modified material zone was formed by symmetrical mirror scanning of the upper and lower surfaces, with each layer having a thickness of approximately 15 μm.

[0076] Then, a 980 nm continuous laser was used for edge thermal-induced release cracking, which was combined with vacuum adsorption differential pressure (ΔP=0.5MPa) to achieve separation.

[0077] After separation, the graphitized layer is removed by low-temperature oxidation treatment at 450℃, followed by double-sided fine grinding and polishing to obtain a heat sink sheet with a thickness of 800±15 μm, TTV≤15 μm, and surface roughness Ra≤25 nm.

[0078] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A method for diamond laser slicing for heat sink materials, characterized in that, Includes the following steps: S1. Inspect the diamond blank to be sliced ​​and determine the location of the target slicing surface; S2. An edge release groove is formed around the target slice surface. S3. The first laser beam is used to scan the interior of the diamond billet to be sliced ​​along the target slice surface to form a continuous or quasi-continuous embedded layer modification zone. S4. A second laser beam is used to irradiate the edge crack release groove, so that the buried layer modification zone and the edge crack release groove are connected and a controllable separation interface is formed. S5. Apply a low load to the diamond billet to separate it into heat sink sheet and mother body residue along the controllable separation interface.

2. The diamond laser slicing method according to claim 1, characterized in that, The thickness of the diamond blank to be sliced ​​is measured, and the position of the target slicing surface is determined based on the thickness of the target heat sink sheet.

3. The diamond laser slicing method according to claim 1, characterized in that, The depth of the edge crack release groove is 20-300μm, and the groove width is 10-80μm.

4. The diamond laser slicing method according to claim 1, characterized in that, The depth of the embedded modified layer from the surface of the diamond billet to be sliced ​​is 30-1500 μm, and the thickness of the modified layer is 2-40 μm.

5. The diamond laser slicing method according to claim 1, characterized in that, The first laser beam is a femtosecond or picosecond laser with a wavelength of 343nm, 515nm, 532nm, 1030nm or 1064nm and a pulse width of 100fs-20ps. The first laser beam adopts a pulse train mode, with each train containing 2-20 sub-pulses and a single train energy of 1-50 μJ.

6. The diamond laser slicing method according to claim 1, characterized in that, The second laser beam is a nanosecond laser or a continuous laser with a wavelength of 355nm, 532nm, 808nm, 980nm or 1064nm.

7. The diamond laser slicing method according to claim 1, characterized in that, The diamond laser slicing method further includes: S6, removing the non-diamond residual layer on the surface of the heat sink and performing double-sided finishing.

8. The diamond laser slicing method according to claim 7, characterized in that, The depth of residual non-diamond layer removal is 0.1-20 μm, and the thickness of the heat sink sheet is preferably 50-1000 μm.

9. A system for implementing the diamond laser slicing method according to any one of claims 1-8, characterized in that, include: The detection unit is used to detect the diamond blank to be sliced ​​and determine the position of the target slicing surface; An edge-release processing unit is used to form edge-release grooves around the area to be sliced. The first laser processing unit is used to perform embedded layer scanning along the target slicing surface to form a continuous or quasi-continuous embedded layer modification zone inside the diamond blank to be sliced. The second laser processing unit is used to assist in irradiating the edge crack release groove, so that the buried layer modification zone and the edge crack release groove are connected and form a controllable separation interface. The low-load separation unit is used to apply a low-load separation to the diamond billet, causing it to separate into heat sink sheet and mother body residue along the controllable separation interface.

10. A diamond heat diffuser sheet, characterized in that, It is prepared by the method described in any one of claims 1 to 7.

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