Semiconductor ultra-thin dicing blade with micro-chip-out structure and manufacturing method thereof

Abstract

The application discloses a semiconductor ultra-thin scribing blade with a micro-chip removal structure and a manufacturing method thereof, and belongs to the technical field of semiconductor wafer cutting processing. The scribing blade comprises a blade body, the thickness of the blade body is 0.02-0.03 mm, and micro-chip removal grooves are arranged on both sides of the blade body and are inclined along the cutting direction; the blade body is provided with a first transition section and a second transition section, the first transition section is provided with a concave arc, the second transition section is provided with a convex arc, the ratio of the radius of the concave arc of the first transition section to the thickness of the blade body is 106.7-160, and the ratio of the radius of the convex arc of the second transition section to the thickness of the blade body is 0.5-0.75; the blade edge has a cross-section profile in the shape of a whole parabola, and the offset amount d1 / d2 of the highest point of the cross-section profile is 0.04-0.07. Through the collaborative design of the micro-chip removal groove structure, the parameter ratio relationship of the transition section and the offset amount of the blade edge, the technical problems of poor chip removal, insufficient rigidity and serious edge collapse of an ultra-thin blade when cutting a third-generation semiconductor material are solved.

Description

Technical Field

[0001] This invention relates to the field of semiconductor wafer dicing technology, specifically to a semiconductor ultrathin dicing blade with a micro-chip removal structure and its manufacturing method. Background Technology

[0002] Third-generation semiconductor materials, represented by silicon carbide and gallium nitride, are widely used in high-end fields such as new energy vehicles, 5G communications, and aerospace due to their excellent properties such as high breakdown voltage, high thermal conductivity, and high temperature resistance. However, these materials have high hardness and brittleness with a Mohs scale of 9 or higher, resulting in severe tool wear during wafer dicing and dicing, making processing extremely difficult. Traditional mechanical cutting easily generates a mechanical stress zone of 40-50μm, leading to a high edge chipping rate and low material utilization. Although laser cutting technology has improved the edge chipping problem to some extent, it has limitations such as high equipment cost, difficulty in completely eliminating the heat-affected zone, and the need for additional wet cleaning after cutting. Therefore, developing high-performance dicing blades is the key to improving the quality and efficiency of third-generation semiconductor wafer dicing.

[0003] Regarding the structural design of dicing blades, existing technologies have proposed various improvement schemes. For example, Chinese invention patent CN117841057B discloses an ultra-thin passivated blade for processing semiconductor materials, which includes a substrate, a first transition portion, a second transition portion, and a cutting edge. The first transition portion is concave and connected between the substrate and the second transition portion, and the second transition portion is convex and connected between the first transition portion and the cutting edge. The cutting edge is parabolic and connected to both ends of the first transition line, and the semiconductor material is cut at the highest point of the parabola. This scheme aims to solve the problems of blade chipping and bending deformation through the passivation design of the parabolic cutting edge. The patent further discloses that the offset ratio of the highest point of the second parabola, d1 / d2, satisfies 0.05≤d1 / d2≤0.1, the radius of the concave arc is 5.5mm, and the radius of the convex arc is 0.03mm. Among them, d1 / d2=0.08 is the preferred value disclosed in the embodiment of the patent.

[0004] However, the aforementioned existing technologies still have the following shortcomings in practical applications: First, the cutting edge of this blade is a smooth surface without a chip removal structure. When cutting ultra-hard and brittle materials, a large number of micron-sized chips cannot be effectively removed, easily accumulating in the cutting area. This leads to increased blade temperature, scratches on the machined surface, and further accelerates tool wear, affecting cutting quality and tool life.

[0005] Secondly, the blade design was not specifically optimized for ultra-thin applications with a thickness of 0.02~0.03mm. As semiconductor devices become increasingly thinner and lighter, the demand for cutting ultra-thin wafers is growing. At such extremely thin thicknesses, the blade's bending rigidity decreases dramatically. Directly using the transition section curvature parameters of thicker blades would fail to effectively distribute stress and provide sufficient structural support, easily leading to warping, cracking, and other problems, thus failing to meet the high-precision cutting requirements of ultra-thin wafers.

[0006] Third, although the patent discloses the offset ratio range of 0.05 to 0.1 for the parabolic cutting edge, it does not disclose the optimal value of this offset and its synergistic relationship with the transition section parameters in the case of ultra-thin cutting blades with integrated chip removal structure, thus failing to achieve the comprehensive effect of controlling the chipping amount at the micron level.

[0007] Chinese invention patent CN117484288B discloses an ultra-thin sharpening blade for processing semiconductor materials. It also employs a transition structure with concave and convex arcs, with a concave arc radius of 5.5 mm and a convex arc radius of 0.03 mm. However, this blade also lacks a chip removal structure, and its cutting edge is a sharpening design of an isosceles triangle, aimed at improving sharpness, which is the opposite of the technical direction of the aforementioned blunting blade.

[0008] Chinese invention patent CN106182475B discloses an ultra-hard blade for cutting wafers and light guide plates. The blade's cutting edge is defined by angular parameters to define symmetrical and asymmetrical portions, aiming to prevent oblique cutting of wafers. This blade does not disclose a micro-chip groove structure, nor does it disclose the radius parameters of the transition section between the concave and convex arcs. Its blade thickness ranges from 0.1 to 0.4 mm, making it unsuitable for cutting ultra-thin wafers with a thickness below 0.03 mm.

[0009] In summary, the existing technology lacks a dicing blade and its manufacturing method that can simultaneously solve the three major technical problems of poor chip removal leading to heat accumulation and surface scratches, stress concentration leading to micro-chipping, and insufficient bending rigidity due to the ultra-thin structure, all within an ultra-thin thickness of 0.02~0.03mm. Summary of the Invention

[0010] The present invention aims to solve the technical problems of existing dicing blades when cutting third-generation semiconductor materials, such as poor chip removal leading to heat accumulation and surface scratches, stress concentration causing micro-chipping, and insufficient bending rigidity of the ultra-thin structure. The invention provides an ultra-thin dicing blade and its manufacturing method that can control the chipping amount at the micron level.

[0011] To solve the above technical problems, the present invention provides a semiconductor ultrathin dicing blade with a micro-chip removal structure, comprising a substrate and a cutting body. The thickness of the cutting body is 0.02~0.03mm. The cutting body is provided with a first transition section and a second transition section. The first transition section is provided with a concave arc, and the second transition section is provided with a convex arc. The ratio of the radius of the concave arc of the first transition section to the thickness of the cutting body is 106.7~160, and the ratio of the radius of the convex arc of the second transition section to the thickness of the cutting body is 0.5~0.75. Micro-chip removal grooves inclined along the cutting direction are provided on both sides of the cutting body. The inclination angle of the micro-chip removal grooves along the cutting direction is 1°~7°. The cutting body has a cutting edge with opposing first and second side surfaces. The cross-sectional profile of the cutting edge is parabolic. The distance from the highest point of the cross-sectional profile to the first side surface is d1, and the distance from the highest point to the second side surface is d2, and d1 / d2 = 0.04~0.07.

[0012] Furthermore, the concave radius of the first transition section is 3.2 mm, and the convex radius of the second transition section is 0.015 mm.

[0013] Furthermore, the depth of the micro chip removal groove is 2~3μm, the width is 1.5~2μm, and the cross-section of the micro chip removal groove is parabolic. By designing the cross-section of the micro chip removal groove as parabolic, stress concentration at the root of the groove can be reduced, providing a chip removal channel while also ensuring the strength of the cutting edge.

[0014] Furthermore, the inclination angle of the micro chip removal groove along the cutting direction is preferably 3°. The 3° inclination angle design can form a directional chip guide channel, allowing the chips to be quickly discharged along the preset direction during the cutting process. At the same time, it forms an effective stress relief channel, guiding the chips to produce controllable curling deformation, thereby reducing the stress concentrated on the cutting edge.

[0015] Furthermore, the depth of the cross-sectional profile is 0.5~1μm, and the surface roughness Ra of the cutting edge is <0.1μm.

[0016] Furthermore, the spacing between adjacent micro chip removal grooves is 50~100μm. This spacing range ensures sufficient chip removal channel density while maintaining the overall structural strength of the cutting edge.

[0017] The present invention also provides a method for manufacturing an ultrathin semiconductor dicing blade with a micro-chip removal structure, comprising the following steps: S1. providing a blade body with a thickness of 0.02~0.03mm; S2. machining micro-chip removal grooves inclined along the cutting direction on both sides of the blade body, wherein the inclination angle of the micro-chip removal grooves along the cutting direction is 1°~7°; S3. machining a concave arc of a first transition section and a convex arc of a second transition section on the blade body, wherein the ratio of the radius of the concave arc of the first transition section to the thickness of the blade body is 106.7~160, and the ratio of the radius of the convex arc of the second transition section to the thickness of the blade body is 0.5~0.75; S4. machining a cross-sectional profile with an overall parabolic shape on the cutting edge of the blade body, wherein the cutting edge has a first side surface and a second side surface opposite to each other, and the distance from the highest point of the cross-sectional profile to the first side surface is d1, the distance from the highest point to the second side surface is d2, and d1 / d2=0.04~0.07.

[0018] Further, in step S3, the radius of the concave arc is 3.2 mm, and the radius of the convex arc is 0.015 mm.

[0019] Furthermore, in step S2, the micro chip removal groove is processed using laser micromachining technology. Laser micromachining can process chip removal groove structures at the micrometer scale with high precision and low thermal impact, avoiding stress damage to the ultra-thin cutting edge caused by traditional machining.

[0020] Furthermore, in step S3, the concave arc and the convex arc are machined using electrical discharge machining (EDM). EDM is suitable for the precision forming of superhard tool materials and can achieve precise machining of concave and convex arcs.

[0021] Furthermore, in step S4, the cross-sectional contour is machined using a CNC grinding machine, and the machining accuracy of the CNC grinding machine is ±0.1μm.

[0022] Compared with the prior art, the semiconductor ultrathin dicing blade with micro-chip removal structure and its manufacturing method provided by the present invention have the following beneficial effects: I. By incorporating micro-chip-removal grooves inclined along the cutting direction on both sides of the cutting edge, the problems of heat accumulation and surface scratches caused by poor chip removal in existing technologies are effectively solved. The micro-chip-removal grooves form a directional chip-guiding channel, allowing micron-sized chips to be rapidly discharged along a preset path. Compared to existing smooth-faced cutting inserts, the cutting temperature can be reduced by more than 20% (approximately 30% in actual measurements). This effect is the result of the synergistic effect of the micro-chip-removal grooves, transition section parameters, and cutting edge offset. The test conditions for the cutting temperature reduction of more than 20% (approximately 30% in actual measurements) mentioned in this specification, which is the result of the synergistic effect of the micro-chip-removal grooves, transition section parameters, and cutting edge offset, are: cutting a 6-inch SiC wafer at a cutting speed of 80 mm / s without external coolant, measured using an infrared thermal imager at a distance of 2 mm from the contact point between the cutting edge and the workpiece. Simultaneously, the micro-chip-removal grooves act as stress-relieving channels, guiding the chips to produce controllable curling deformation, effectively reducing stress concentrated on the cutting edge and minimizing the risk of micro-chipping. The micro chip removal groove adopts a parabolic cross-section design, which further reduces stress concentration at the root of the groove, balancing chip removal efficiency and cutting body strength.

[0023] Second, by establishing a specific ratio relationship between the transition section parameters and the blade thickness, the ratio of the concave radius of the first transition section to the blade thickness reaches 106.7~160, and the ratio of the convex radius of the second transition section to the blade thickness reaches 0.5~0.75, thus precisely matching the transition section parameters with the ultra-thin blade thickness of 0.02~0.03mm. In a preferred embodiment of the present invention, the concave radius is 3.2mm, and the convex radius is 0.015mm. In comparison, if the blade thickness is scaled proportionally from the commonly used 0.4mm to 0.03mm in the prior art, the concave radius should be approximately 0.42mm. However, the concave radius of 3.2mm in the present invention is much larger than this proportionally scaled value. This is not a simple linear scaling result, but rather the optimal parameter determined after specialized mechanical analysis and experimental verification. Finite element analysis results show that when using this parameter combination, the maximum stress value of the blade under load is reduced by approximately 30% compared to the traditional design. The boundary conditions for the finite element analysis described in this specification are as follows: the root of the cutting edge (the connection between the base and the first transition section) is set as a fixed constraint; a uniformly distributed load perpendicular to the tangent direction of the cutting edge is applied at the highest point of the cutting edge, with a load magnitude of 50 N / mm; hexahedral elements are used for the mesh, with a global mesh size of 0.005 mm; and the material parameters are taken as an ultrafine-grained cemented carbide with an elastic modulus of 600 GPa and a Poisson's ratio of 0.22. Three-point bending test results show that the bending resistance is improved by 22% compared to existing inserts of the same thickness, and the vibration amplitude is reduced by 25%. The test conditions for the three-point bending test described in this specification are: the specimen size is a cutting edge thickness of 0.02 mm, a width of 5 mm, and a span of 10 mm; the loading speed is 0.5 mm / min; and the reference is an insert of the same thickness with a concave radius of 5.5 mm and a convex radius of 0.03 mm. This parameter combination provides a reliable mechanical basis for the stable operation of the micro-chip groove structure and the cutting edge.

[0024] Third, by setting the offset of the highest point of the cutting edge profile to d1 / d2 = 0.04~0.07 (preferably 0.06), under the synergistic conditions of the micro-chip groove and specific transition section parameters, a uniform distribution of cutting force along the length of the cutting edge is achieved, effectively balancing cutting efficiency and tool life. This offset range allows the cutting edge to maintain sharpness while enhancing structural strength, avoiding the problems of increased cutting resistance due to excessive offset or insufficient rigidity due to insufficient offset in existing technologies.

[0025] IV. Through the synergistic effect of the three core technologies mentioned above, the dicing blade of this invention can control the chipping amount to ≤3μm when dicing 6-inch SiC wafers, achieving a cutting accuracy of ±0.5μm, controlling the heat-affected zone within the range of 10~15μm, and achieving a cutting speed of up to 80mm / s. Tool life is increased by 35% compared to existing passivated blades, and chip yield is increased to 99.2%. The chipping amount measurement method described in this specification is as follows: using an optical microscope at 500x magnification, 20 measurement points are taken at equal intervals along the dicing path to measure the chipping width, and the maximum value is taken as the chipping amount. The heat-affected zone is determined by observing the width of the material lattice distortion region using cross-sectional SEM. The tool life criterion is that the edge wear reaches 20% of the initial edge width. The statistical caliber of chip yield is the percentage of chips that pass cleaning and visual inspection after dicing (no chipping exceeding 5μm, no cracks) out of the total number of diced chips. The benchmark for improving the chip yield to 99.2% is 85% under the conditions of cutting a 6-inch SiC wafer with a traditional diamond grinding wheel blade at a cutting speed of 80mm / s and a chipping amount of >30μm.

[0026] V. The manufacturing method of this invention uses laser micromachining technology to prepare micro chip grooves, and utilizes the cold working characteristics of laser to avoid the generation of heat-affected zones and microcracks, thus ensuring the machining accuracy of micron-level structures. Electrical discharge machining and CNC grinding are used to achieve precise forming of transition sections and cutting edges. The process is mature and reliable, has good compatibility with existing production equipment, and is easy to realize industrial application. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the radial cross-section of the present invention; Figure 3 yes Figure 2 A magnified view of a portion of point A in the middle; Figure 4 This is a schematic diagram of the cross-sectional profile of the cutting edge of the present invention; Figure 5 This is a schematic diagram showing the distribution and cross-section of the micro chip removal grooves of the present invention; Figure 6 This is a process flow diagram of the method for manufacturing an ultrathin semiconductor dicing blade with a micro-chip removal structure according to an embodiment of the present invention.

[0028] Explanation of reference numerals in the attached figures: 1-Base; 2-Cutting body; 3-First transition section; 4-Second transition section; 5-Cutting edge; 6-Concave arc; 7-Convex arc; 8-First transition line; 9-Second transition line; 10-First side of cutting edge; 11-Second side of cutting edge; 12-Micro chip removal groove. Detailed Implementation

[0029] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention. The embodiments are only used to explain the present invention and do not constitute a limitation on the scope of protection of the present invention.

[0030] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0031] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "setting" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0032] The "dicing blade" mentioned in this invention refers to a rotary cutting tool used in the dicing process of semiconductor wafers. It is usually mounted on the spindle of a dicing machine and performs dicing on the wafer by high-speed rotation.

[0033] The "third-generation semiconductor material" mentioned in this invention refers to wide bandgap semiconductor materials represented by silicon carbide and gallium nitride. These materials have physical properties of high hardness and high brittleness, which puts forward high requirements for the performance of cutting tools.

[0034] Example 1 Please see Figures 1 to 5 This invention provides a semiconductor ultrathin dicing blade with a micro-chip removal structure. The dicing blade includes a substrate 1, a cutting edge 2, a first transition section 3, a second transition section 4, and a cutting edge 5.

[0035] like Figure 1As shown, the substrate 1 is located in the upper region of the dicing blade, providing overall structural support and a mounting base for the blade. The substrate 1 is preferably made of ultrafine-grained cemented carbide with a grain size ≤0.5μm, providing structural support for the blade due to its high hardness and good wear resistance. To meet the cutting requirements of ultra-hard and brittle semiconductor materials such as silicon carbide and gallium nitride, a diamond coating can be further applied to the surface of the cutting body 2. This diamond coating is prepared using chemical vapor deposition (CVD) and has a thickness of 2~5μm to improve the surface hardness and wear resistance of the cutting body, extending the tool's service life.

[0036] The cutting edge 2 is connected to the base 1 below. The thickness of the cutting edge 2 is 0.02~0.03mm, and the width is 5~10mm. This thickness range is specifically designed for the cutting requirements of ultra-thin wafers with a thickness of less than 30μm, and can match the width requirements of extremely narrow kerfs, reducing material loss during the cutting process. However, such an extremely thin thickness causes a sharp decrease in the bending rigidity of the cutting edge 2, placing higher demands on the structural design of the transition section and the cutting edge.

[0037] like Figures 1 to 2 As shown, the cutting edge 2 is provided with a first transition section 3 and a second transition section 4. One end of the first transition section 3 is connected to the base 1, and the other end of the first transition section 3 is connected to one end of the second transition section 4. The other end of the second transition section 4 is connected to the cutting edge 2. The first transition section 3 is connected between the base 1 and the second transition section 4 by a bilaterally symmetrical concave arc 6, and the second transition section 4 is connected between the first transition section 3 and the cutting edge 2 by a bilaterally symmetrical convex arc 7. A first transition line 8 is formed at the connection between the cutting edge 2 and the second transition section 4, and a second transition line 9 is formed at the connection between the first transition section 3 and the base 1. Through this transition section structure design, during the cutting process, only the cutting edge 5 abuts against the semiconductor material, and the cut semiconductor material deviates from the base 1 between the first transition line 8 and the second transition line 9, thereby avoiding contact between the base 1 and the processed surface and causing scratches.

[0038] like Figure 2As shown, there is a specific ratio between the radius R1 of the concave arc 6 of the first transition section 3 and the thickness of the cutting body 2, that is, the ratio of the concave arc radius to the cutting body thickness is 106.7~160. In a preferred embodiment of the present invention, the radius R1 of the concave arc 6 is 3.2mm. This concave arc radius value is specifically adjusted compared to the 5.5mm commonly used in the prior art. Compared with the prior art, the 3.2mm concave arc radius makes the stress dispersion area more concentrated, achieving a more effective stress uniformity distribution within the limited transition section length of the ultra-thin blade. Finite element analysis results show that when using this concave arc radius, the maximum stress value of the blade under stress is reduced by about 30% compared with the traditional design. The boundary conditions of the finite element analysis are: the root of the cutting body is set as a fixed constraint, a uniformly distributed load perpendicular to the tangent direction of the cutting edge is applied at the highest point of the cutting edge, the load magnitude is 50N / mm, the mesh uses hexahedral elements, the global mesh size is 0.005mm, and the material parameters are taken as the elastic modulus of ultrafine grain cemented carbide of 600GPa and Poisson's ratio of 0.22. The traditional design refers to a blade of the same thickness with a concave radius of 5.5 mm and a convex radius of 0.03 mm.

[0039] There is also a specific ratio between the radius R2 of the convex arc 7 of the second transition section 4 and the thickness of the cutting body 2, namely, the ratio of the convex arc radius to the cutting body thickness is 0.5~0.75. In a preferred embodiment of the present invention, the radius R2 of the convex arc 7 is 0.015mm. This convex arc radius value is 50% smaller than the commonly used 0.03mm in the prior art. In the design of ultra-thin inserts, the precise control of the convex arc radius is particularly critical: an excessively large convex arc radius will increase cutting resistance, leading to increased cutting temperature and accelerated tool wear; an excessively small convex arc radius may not be able to effectively disperse stress, increasing the risk of chipping. The convex arc radius of 0.015mm has been verified through extensive experiments to achieve the best balance between stress dispersion and cutting resistance in ultra-thin insert applications.

[0040] It should be noted that the preferred parameter combination of the concave radius of 3.2 mm and the convex radius of 0.015 mm is not a simple proportional scaling of existing technical parameters. If calculated based on a proportional scaling from the commonly used 0.4 mm to 0.03 mm in the prior art, the concave radius should be approximately 0.42 mm. However, the concave radius of 3.2 mm in this invention is much larger than this proportionally scaled value; the proportionally scaled value of the convex radius is approximately 0.002 mm, and the 0.015 mm in this invention also far exceeds this value. This indicates that the transition parameters of this invention are the result of a redesign specifically for a blade thickness of 0.02~0.03 mm after mechanical analysis and experimental verification, and are not a simple linear scaling.

[0041] The three-point bending test results show that this parameter combination improves the bending resistance by 22% and reduces the vibration amplitude by 25% compared to existing inserts of the same thickness. The test conditions for the three-point bending test were: sample dimensions of 0.02 mm thickness, 5 mm width, and 10 mm span; and a loading speed of 0.5 mm / min. Existing inserts of the same thickness refer to inserts with a concave radius of 5.5 mm and a convex radius of 0.03 mm. This parameter combination provides a reliable mechanical basis for the stable operation of the micro-chip groove structure and the cutting edge.

[0042] like Figures 2 to 4 As shown, the cutting edge 5 has a parabolic cross-sectional profile. In this invention, "a parabolic cross-sectional profile" means that the cutting edge 5, along the thickness direction of the blade, presents a smooth curve shape that is parabolic or approximately parabolic, with its two ends connected to the two side surfaces of the blade body 2. The highest point of the curve constitutes the cutting contact point. When d1=d2 (i.e., the highest point is located on the center line of symmetry), the cross-sectional profile is a standard single parabola; when d1≠d2 (i.e., the highest point deviates from the center line of symmetry), the cross-sectional profile is a composite curve formed by smoothly splicing two parabolas with different parameters at the highest point, still presenting an overall parabolic shape. The parabolic shape enables the cutting force to be evenly distributed along the length of the cutting edge, avoiding the local stress concentration problem present in traditional straight or arc-shaped cutting edges.

[0043] like Figure 4 As shown, the highest point of the cross-sectional profile deviates from the symmetrical center line of the cutting edge 2, forming an asymmetrical cutting edge configuration. The two sides of the cutting edge 5 are defined as the first side surface 10 and the second side surface 11, respectively. Let d1 be the distance from the highest point of the cross-sectional profile to the first side surface 10, and d2 be the distance from the highest point of the cross-sectional profile to the second side surface 11. The offset ratio d1 / d2 is 0.04~0.07, preferably 0.06. This offset ratio is the optimal parameter obtained through extensive experimental data optimization: when the offset is too small, the cutting edge rigidity is insufficient, and bending deformation is easily generated in the case of extremely thin inserts; when the offset is too large, it will increase cutting resistance, leading to increased cutting temperature and accelerated tool wear. An offset ratio of 0.06 achieves the best balance between cutting efficiency and tool life, while a range of 0.04~0.07 can achieve better edge chipping control than existing technologies.

[0044] In one specific embodiment of the present invention, the cross-sectional profile can be a symmetrical parabola, that is, its highest point is located on the center line of symmetry of the cutting edge 2, d1=d2. The symmetrical parabolic cutting edge is suitable for application scenarios with high requirements for the quality of the cutting surface and specific requirements for the self-centering performance of the cutting edge.

[0045] In another specific embodiment of the invention, the cross-sectional profile can be a parabola with different opening coefficients. For example, the opening coefficient of the cross-sectional profile is 0.8. This opening coefficient controls the widening of the parabola shape and affects the distribution characteristics of the cutting force on the cutting edge. The larger the opening coefficient, the flatter the parabola and the wider the cutting edge contact area; the smaller the opening coefficient, the sharper the parabola and the closer the cutting edge is to a triangle.

[0046] The depth of the cross-sectional profile, i.e., the vertical distance from the highest point of the cutting edge to the junction of the cutting edge and the cutting body, is preferably 0.5~1μm. This depth range ensures that the cutting edge has sufficient strength to resist cutting impact while maintaining the necessary sharpness for efficient cutting. The surface roughness Ra of the cutting edge 5 is preferably less than 0.1μm to reduce frictional resistance during cutting, lower cutting temperature, and prevent the rough cutting edge surface from causing microscopic scratches on the processed wafer surface.

[0047] like Figure 5 As shown, micro-chip removal grooves 12 inclined along the cutting direction are provided on both sides of the cutting body 2. Micro-chip removal grooves refer to microscopic groove structures machined on the surface of the cutting body to guide micron-sized chips generated during cutting out along a predetermined direction. The micro-chip removal grooves 12 are fabricated using laser micromachining technology and are symmetrically distributed on both sides of the cutting body 2. Each micro-chip removal groove 12 extends continuously along its own extension direction, that is, a single groove is uninterrupted from its starting end to its ending end; while there is a certain groove spacing between adjacent micro-chip removal grooves 12 to meet the strength requirements of the cutting body.

[0048] like Figure 5 As shown, the micro-chip removal groove 12 is inclined along the cutting direction, with an inclination angle preferably between 1° and 7°, and more preferably 3°. The design principle of the 3° inclination angle is that the micro-chip removal groove 12 forms a directional chip-guiding channel that is wider at the front and narrower at the back, and deeper at the front and shallower at the back, allowing the chips to be discharged quickly along a preset direction during the cutting process. This design causes the chips to first contact the anti-chip surface of the chip removal groove and bend with a small bending radius, and then contact the anti-chip surface later in the area of ​​lower cutting speed and form a larger bending radius. The different degrees of deformation at both ends cause the chips to flow towards the cutting surface, where they break upon contact, forming controllable C-shaped chips. At the same time, this inclination angle forms an effective stress relief channel. By guiding the chips to produce controllable curling deformation, the chips produce a composite curling of upward and transverse curling, forming a stress gradient in the cutting area, effectively releasing the stress concentrated on the cutting edge 5, and reducing the risk of micro-chipping of the cutting edge.

[0049] In one specific embodiment of the present invention, the cross-sectional shape of the micro chip removal groove 12 is parabolic. For example... Figure 5As shown, the parabolic cross-section micro-chip groove can reduce stress concentration at the groove root. Compared with rectangular or V-shaped cross-section grooves, it minimizes the weakening of the strength of the cutting body 2 while providing the same chip removal channel area, thus balancing chip removal efficiency and the structural integrity of the cutting body 2. The geometric characteristics of the parabolic cross-section are: the ratio of the cross-section opening width to the groove depth is 0.5~1.5, the radius of curvature of the groove bottom is not less than 50% of the groove depth, the overall cross-section profile is smooth without sharp edges, and the groove edge and the cutting body surface are smoothly transitioned.

[0050] In another specific embodiment of the present invention, the cross-sectional shape of the micro chip removal groove 12 can also be arc-shaped, V-shaped or trapezoidal, as long as it can provide an effective chip removal channel and stress relief function.

[0051] like Figure 5 As shown, the depth of the micro-chip removal groove 12 is 2~3μm, and the width is 1.5~2μm. This size range is specifically designed for the size characteristics of micron-sized chips generated during the cutting of third-generation semiconductor materials. The depth and width provide sufficient chip-carrying space while ensuring that the structural strength of the cutting edge 5 is not excessively weakened. If the groove depth is too large, it will excessively weaken the strength of the ultra-thin cutting body 2; if the groove depth is too small, it will not be able to accommodate and guide the chips out.

[0052] like Figure 5 As shown, the spacing between adjacent micro-chip removal grooves 12 is 50~100μm. This spacing range ensures sufficient chip removal channel density while maintaining the overall structural strength of the cutting body 2 along its length. The selection of the groove spacing needs to comprehensively consider both chip removal efficiency and structural strength: overly dense chip removal grooves will reduce the rigidity of the cutting body, while overly sparse grooves will result in insufficient chip removal effect.

[0053] The aforementioned cross-sectional profile offset d1 / d2 of the cutting edge 5 (preferably 0.06), the structural parameters of the micro chip groove 12, and the transition section parameters create a synergistic effect. The micro chip groove 12 improves chip removal efficiency and releases cutting edge stress, creating mild working conditions for the transition section and the cutting edge. The bending rigidity and uniform stress distribution provided by the transition section parameters provide a mechanical basis for the stable existence of the micro chip groove 12 and the precise operation of the cutting edge 5. The specific offset range of 0.04 to 0.07 of the cross-sectional profile, under the combined conditions of the first two factors, further optimizes the cutting force distribution, achieving the best balance between cutting efficiency and tool life.

[0054] Practical application tests show that the semiconductor ultrathin dicing blade with micro-chip removal structure of this embodiment, when dicing 6-inch silicon carbide wafers, controls the chipping amount to ≤3μm, achieves a cutting accuracy of ±0.5μm, controls the heat-affected zone within the range of 10~15μm, and achieves a cutting speed of up to 80mm / s. Tool life is improved by 35% compared to existing passivated blades, and chip yield is increased to 99.2%. The chipping amount is measured using an optical microscope at 500x magnification, taking 20 equally spaced measurement points along the dicing path to measure the chipping width, and taking the maximum value as the chipping amount. The heat-affected zone is determined by observing the width of the material lattice distortion region using cross-sectional SEM. The tool life is judged when the edge wear reaches 20% of the initial edge width. The benchmark for improving the chip yield to 99.2% is 85% under the conditions of cutting 6-inch silicon carbide wafers with traditional diamond grinding wheels at a cutting speed of 80mm / s and a chipping amount >30μm.

[0055] The following analyzes the force on the cutting edge of the blade in this embodiment when cutting semiconductor materials. The cutting edge 5 is subjected to a reverse cutting force F from the semiconductor material, with the direction of F along the normal to the tangent at the highest point of the cross-sectional profile. The torque on one side of the blade body 2 and the second transition section 4 is M1, and the torque on one side of the base body 1 and the first transition section 3 is M2. The bending strength of the blade material is M. The relationships M1=F×S1 / 4 and M2=F×S2 / 4 are satisfied, where S1 is the length of the first transition line 8, S2 is the length of the second transition line 9, and M1<M2<M. This torque relationship shows that the torque generated by the cutting force in each structural part of the blade decreases step by step and is all less than the bending strength limit of the material, ensuring the structural safety of the blade under normal cutting conditions.

[0056] As can be seen from the above analysis, the semiconductor ultrathin dicing blade with micro-chip removal structure in this embodiment effectively solves the problems of heat accumulation and surface scratches caused by poor chip removal during ultrathin blade cutting by setting micro-chip removal grooves 12 on both sides of the blade body 2; through the targeted design of the ratio of the concave arc radius of the first transition section to the blade body thickness and the ratio of the convex arc radius of the second transition section to the blade body thickness, sufficient bending rigidity is provided for the ultrathin blade; through the precise selection of the cross-sectional profile offset d1 / d2 = 0.04~0.07, the cutting force distribution is optimized under the synergistic conditions of the micro-chip removal grooves 12 and the transition section parameters. The synergistic effect of the above three core technologies achieves micron-level cutting accuracy with edge chipping ≤3μm.

[0057] To further demonstrate the synergistic effect and inventiveness of the technical solution of this invention, the applicant conducted comparative experiments under the same experimental conditions. The experimental conditions were: 6-inch silicon carbide wafer, cutting speed 80 mm / s, and no external coolant. The results of the comparative experiments are shown in Table 1. Table 1

[0058] Table 2 Comparison of cutting effects with different offsets d1 / d2

[0059] Table 2 shows that within the range of d1 / d2 = 0.04 to 0.07, the chipping amount can be controlled below 4 μm, significantly better than the effects of 0.08 (5 μm) and 0.10 (6.5 μm) in the range disclosed in D1. Among these, the chipping amount is lowest (≤3 μm) and the tool life is improved the most (35%) when d1 / d2 = 0.06, confirming that 0.06 is the optimal value. This optimal value could not have been reasonably predicted within the range of 0.05 to 0.1 disclosed in D1, fully demonstrating the synergistic inventiveness and unexpected technical effects of the present invention.

[0060] In particular, the D1 implementation scheme corresponds to the dicing blade disclosed in Chinese invention patent CN117841057B mentioned in the background art. The above-mentioned tool life benchmark value (100%) corresponds to a cumulative cutting length of 5000m for cutting SiC wafers, and the tool life percentage increase is calculated based on this benchmark value.

[0061] The comparative experimental results above show that neither introducing a micro-chip removal groove alone (Comparative Scheme B) nor adjusting the transition section parameters alone (Comparative Scheme A) can achieve the edge chipping effect of ≤3μm as described in this invention. Simultaneously using a micro-chip removal groove and the adjusted transition section parameters (Comparative Scheme C), the edge chipping is improved to 5μm, but still does not reach the ≤3μm level of this invention. Only after adjusting the offset from the preferred value of D1 (0.08) to the range of 0.04~0.07 as described in this invention does the edge chipping significantly decrease. The above results fully demonstrate the synergistic effect of the micro-chip removal groove and the transition section parameters. To further explore the optimal value and predictability of the offset d1 / d2 under this synergistic system, the applicant systematically tested the cutting effect of different d1 / d2 values ​​under the same experimental conditions. The results are shown in Table 2. Example 2 Please see Figure 6 This invention also provides a method for manufacturing an ultrathin semiconductor dicing blade with a micro-chip removal structure. This method is used to manufacture the ultrathin semiconductor dicing blade with a micro-chip removal structure described in Embodiment 1 above. The manufacturing method includes the following steps: Step S1: Provide a blade body 2 with a thickness of 0.02~0.03mm.

[0062] In this step, firstly, an ultrafine-grained cemented carbide is selected as the base material, wherein the grain size of the ultrafine-grained cemented carbide is ≤0.5μm. For the cutting body made of ultrafine-grained cemented carbide, deep cryogenic treatment can be performed first to eliminate internal stress in the material and obtain a more stable tool material matrix. The specific process of deep cryogenic treatment can be as follows: the ultrafine-grained cemented carbide base material, which has been sintered at high temperature, is subjected to temperature profile treatment at -200℃ for 72 hours. Afterwards, through slicing and precision grinding processes, the thickness of the cutting body 2 is precisely controlled within the range of 0.02~0.03mm, and the flatness and parallelism of the two sides of the cutting body 2 are ensured to meet the accuracy requirements of subsequent processing.

[0063] Step S2: Micro chip removal grooves 12 inclined along the cutting direction are machined on both sides of the cutting body 2.

[0064] This step preferably employs laser micromachining. Laser micromachining technology utilizes high-energy photon beams to remove or modify materials, and is particularly suitable for machining micron-scale structures on the surface of ultrathin blades.

[0065] In one specific embodiment of the present invention, a picosecond laser is used to process the micro-chip groove 12. The processing parameters of the picosecond laser are: wavelength 355nm, pulse width 10ps, laser power 5W, scanning speed 1000mm / s, and pulse frequency 100kHz. The ultraviolet picosecond laser directly breaks the molecular bonds of the material using the cold processing principle. The processed structure has no molten zone, no recast layer, and no microcracks. It has high processing precision and is not limited by the diffraction limit of light. It is particularly suitable for processing micron-level precision structures on the surface of a cutting tool with a thickness of only 0.02~0.03mm.

[0066] In another specific embodiment of the present invention, a femtosecond laser can also be used to process the micro chip groove 12. Femtosecond lasers have shorter pulse widths and smaller heat-affected zones, making them suitable for processing ultra-thin materials that are more sensitive to thermal damage.

[0067] During the processing, the laser beam's trajectory is controlled by a galvanometer scanning system to precisely form micro-chip removal grooves 12 with a depth of 2-3 μm and a width of 1.5-2 μm. The grooves are tilted at a set angle along the cutting direction, with a parabolic cross-sectional shape, and the spacing between adjacent grooves is 50-100 μm. The processing quality of the micro-chip removal grooves 12 is monitored in real time by an online detection system to ensure process stability and product consistency.

[0068] Step S3: A concave arc 6 of the first transition section 3 and a convex arc 7 of the second transition section 4 are machined on the cutting edge 2. The ratio of the radius of the concave arc of the first transition section 3 to the thickness of the cutting edge 2 is 106.7~160, and the ratio of the radius of the convex arc of the second transition section 4 to the thickness of the cutting edge 2 is 0.5~0.75. In a preferred embodiment, the radius R1 of the concave arc 6 is 3.2 mm, and the radius R2 of the convex arc 7 is 0.015 mm.

[0069] Electrical discharge machining (EDM) is the preferred process for this step. EDM uses pulsed discharge between an electrode and the workpiece to remove material, and it features high machining accuracy and no macroscopic cutting force, making it particularly suitable for precision forming of superhard tool materials.

[0070] In one specific embodiment of the present invention, a precision electrical discharge machining (EDM) device is used, and the machining accuracy is controlled within ±0.002mm. First, the concave arc 6 of the first transition section 3 is machined to ensure that its radius accurately reaches the design value; then, the convex arc 7 of the second transition section 4 is machined to ensure that its radius accurately reaches the design value.

[0071] In another specific embodiment of the present invention, a precision forming grinding process can also be used, using a forming grinding wheel with a corresponding arc-shaped profile for grinding.

[0072] Step S4: A parabolic cross-sectional profile is machined on the cutting edge 5 of the blade body 2. The cutting edge 5 has a first side 10 and a second side 11 with opposite sides. The distance from the highest point of the cross-sectional profile to the first side 10 is d1, and the distance from the highest point to the second side 11 is d2, and d1 / d2 = 0.04~0.07.

[0073] This step is preferably performed using a CNC grinding machine for precision grinding.

[0074] In one specific embodiment of the present invention, the machining accuracy of the CNC grinding machine is ±0.1μm. By precisely programming and controlling the grinding path, grinding is performed according to the defined contour curve to ensure the cross-sectional contour accuracy and surface quality of the cutting edge 5.

[0075] After machining, the cutting edge 5 can be precision ground and polished to achieve a surface roughness Ra of less than 0.1 μm. The quality and shape accuracy of the cutting edge can be detected by a microhardness tester and a profilometer to ensure that the offset d1 / d2 falls precisely within the design range of 0.04~0.07, preferably reaching 0.06.

[0076] In one specific embodiment of the present invention, step S2 is performed before step S3, that is, the micro chip removal groove 12 is first machined on the cutting body 2, and then the concave arc 6 and convex arc 7 of the transition section are machined.

[0077] In another specific embodiment of the present invention, step S3 can also be performed before step S2, that is, the concave arc 6 and convex arc 7 of the transition section are processed first, and then the micro chip removal groove 12 is processed on the cutting body 2.

[0078] The choice between the two processing sequences depends mainly on the specific equipment configuration and process route arrangement, as long as the final formed cutting body 2 has a complete micro chip removal groove 12, transition section parameters and cutting edge 5 cross-sectional profile.

[0079] Variant Example Description In the above embodiment, the concave radius R1 is illustrated using 3.2 mm as an example. In practical applications, the ratio of the concave radius R1 to the blade thickness ranges from 106.7 to 160. When the blade thickness is 0.02 mm, the concave radius can be selected within the range of 2.134 to 3.2 mm (corresponding to a ratio of 106.7 to 160), and the convex radius can be selected within the range of 0.010 to 0.015 mm (corresponding to a ratio of 0.5 to 0.75); when the blade thickness is 0.03 mm, the concave radius can be selected within the range of 3.2 to 4.8 mm (corresponding to a ratio of 106.7 to 160), and the convex radius can be selected within the range of 0.015 to 0.0225 mm (corresponding to a ratio of 0.5 to 0.75). Finite element analysis shows that, within the above parameter range, the maximum stress value of the blade under stress is reduced by 25% to 30% compared with the traditional design, and the bending resistance is improved by 18% to 22%, indicating that the parameters within this ratio range can achieve the technical effects of the present invention.

[0080] The specific dimensions of the micro chip removal groove 12 can be adjusted within a certain range according to the cutting characteristics of different semiconductor materials. As long as its micron-scale and directional chip removal function are maintained, they are all within the scope of the micro chip removal groove.

[0081] The tilt angle of the micro chip removal groove 12 can be optimized within the range of 1° to 7° according to the specific cutting speed range and chip flow characteristics, so as to adapt to different wafer materials and cutting process parameters.

[0082] The specific shape of the parabolic cross-sectional profile of the cutting edge 5 can be adjusted according to the requirements of cutting force distribution, for example, by using quadratic function curves with different parameters or an approximate parabolic shape formed by multi-point fitting. When the offset d1≠d2, the cross-sectional profile is formed by smoothly splicing two parabolic segments with different parameters at the highest point, and the overall shape still remains a smooth parabolic curve.

[0083] The technical solution of this invention is not only applicable to wafer dicing of third-generation semiconductor materials such as silicon carbide and gallium nitride, but also applicable to precision dicing of other ultra-hard and brittle materials such as sapphire and quartz glass.

[0084] The processing methods in each step of the manufacturing method of the present invention are not limited to the specific processes listed in the above embodiments, and equivalent or better alternative processes can be adopted as micro-nano fabrication technology advances.

[0085] Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention shall be included within the scope of protection of the claims of this invention.

Claims

1. A semiconductor ultrathin dicing blade with a micro-chip removal structure, comprising a substrate and a cutting edge, wherein the thickness of the cutting edge is 0.02~0.03 mm, characterized in that, The blade body is provided with a first transition section and a second transition section. The first transition section is provided with a concave arc, and the second transition section is provided with a convex arc. One end of the concave arc is connected to the base body, and the other end is connected to the second transition section. The ratio of the radius of the concave arc of the first transition section to the thickness of the blade body is 106.7~160, and the ratio of the radius of the convex arc of the second transition section to the thickness of the blade body is 0.5~0.

75. Micro chip removal grooves inclined along the cutting direction are provided on both sides of the cutting body, and the inclination angle of the micro chip removal grooves along the cutting direction is 1°~7°; The blade has a cutting edge, the cutting edge has a first side and a second side opposite to each other, the cross-sectional profile of the cutting edge is parabolic in shape, the distance from the highest point of the cross-sectional profile to the first side is d1, the distance from the highest point to the second side is d2, and d1 / d2 = 0.04~0.

07.

2. The semiconductor ultrathin dicing blade with a micro-chip removal structure according to claim 1, characterized in that, The concave radius of the first transition section is 3.2 mm, and the convex radius of the second transition section is 0.015 mm.

3. The semiconductor ultrathin dicing blade with a micro-chip removal structure according to claim 1, characterized in that, The depth of the micro chip removal groove is 2~3μm, the width is 1.5~2μm, the cross-section of the micro chip removal groove is parabolic, the ratio of the opening width to the groove depth of the parabolic cross-section is 0.5~1.5, the radius of curvature of the groove bottom is not less than 50% of the groove depth, and the groove spacing between adjacent micro chip removal grooves is 50~100μm.

4. The semiconductor ultrathin dicing blade with a micro-chip removal structure according to claim 1, characterized in that, The micro chip removal groove has an inclination angle of 3° along the cutting direction, the depth of the cross-sectional profile is 0.5~1μm, and the surface roughness Ra of the cutting edge is <0.1μm.

5. The semiconductor ultrathin dicing blade with a micro-chip removal structure according to claim 1, characterized in that, The ratio d1 / d2 is 0.

06.

6. A method for manufacturing a semiconductor ultrathin dicing blade with a micro-chip removal structure, characterized in that, Includes the following steps: S1. A blade with a thickness of 0.02~0.03mm is provided; S2. Micro chip removal grooves inclined along the cutting direction are machined on both sides of the cutting body, and the inclination angle of the micro chip removal grooves along the cutting direction is 1°~7°; S3. A concave arc of a first transition section and a convex arc of a second transition section are machined on the blade body. The ratio of the radius of the concave arc of the first transition section to the thickness of the blade body is 106.7~160, and the ratio of the radius of the convex arc of the second transition section to the thickness of the blade body is 0.5~0.

75. S4. A parabolic cross-sectional profile is machined on the cutting edge of the blade body. The cutting edge has a first side and a second side opposite to each other. The distance from the highest point of the cross-sectional profile to the first side is d1, and the distance from the highest point to the second side is d2, and d1 / d2 = 0.04~0.

07.

7. The method for manufacturing a semiconductor ultrathin dicing blade with a micro-chip removal structure according to claim 6, characterized in that, In step S3, the radius of the concave arc is 3.2 mm, and the radius of the convex arc is 0.015 mm.

8. The method for manufacturing a semiconductor ultrathin dicing blade with a micro-chip removal structure according to claim 6, characterized in that, In step S2, the micro chip groove is processed using laser micromachining technology; in step S3, the concave arc and the convex arc are processed using electrical discharge machining technology.

9. The method for manufacturing a semiconductor ultrathin dicing blade with a micro-chip removal structure according to claim 6, characterized in that, In step S4, the cross-sectional contour is machined using a CNC grinding machine, and the machining accuracy of the CNC grinding machine is ±0.1μm.

10. The method for manufacturing a semiconductor ultrathin dicing blade with a micro-chip removal structure according to claim 8, characterized in that, The micro chip removal groove has a depth of 2~3μm, a width of 1.5~2μm, and a parabolic cross-section; the depth of the cross-sectional profile is 0.5~1μm, and d1 / d2=0.06.

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