Wafer positioning groove chamfering grinding head for wafer Notch notch chamfering and manufacturing method

Abstract

According to the wafer positioning groove chamfering grinding head for wafer Notch notch chamfering and the manufacturing method, a conical detachable split mold is adopted for pressing, the conical detachable split mold comprises a sintering protective sleeve, an inner conical mold sleeve, a split outer conical porous mold cavity, an upper pressing head and a lower pressing head, and the split outer conical porous mold cavity is defined by a plurality of split conical bodies; the conical degree of the outer conical surface of the inner conical die sleeve is kept consistent with that of the inner conical die sleeve, a plurality of semi-cylindrical die cavities are further formed between the adjacent sub-cones, and the semi-cylindrical die cavities between the adjacent sub-cones are combined to form a plurality of complete cylindrical die cavities which are used for placing upper and lower pressure heads and grinding material layers, so that the machining of a precise chamfering procedure of a Notch notch is realized. The problems that the wafer Notch notch is poor in surface quality and concentrated in stress are solved, and low-damage and high-efficiency precision machining of the wafer Notch notch is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of wafer processing, and particularly relates to a wafer positioning groove chamfering grinding head for chamfering a wafer Notch cut and a manufacturing method thereof. Background Art

[0002] In order to identify the specific crystal direction on the wafer or chip, which is beneficial to the identification and positioning requirements of the chip in different processes in the IC factory, the X-ray diffraction method is generally used to measure the direction and position the edge of the wafer according to the process requirements after the orientation and cylindrical grinding of the crystal rod are completed.

[0003] As the diameter of the wafer increases, in order to reduce wafer waste, the wafer positioning is changed from the original plane to a V-shaped groove (Notch). In the wafer manufacturing process, the Notch is exactly where the force is most concentrated, so the surface grinding quality of the Notch is particularly important. To solve this problem, efficient and high-quality Notch cut chamfering wafer chamfering grinding heads are urgently needed to ensure the surface quality of the wafer Notch, reduce stress concentration, and improve the wafer yield.

[0004] The main issues at present: 1. The surface quality of wafers processed by traditional wafer chamfering grinding heads is poor, and defects such as deep grooves and scratches are prone to occur; 2. Traditional wafer chamfering grinding heads use single pressing and sintering, which results in low processing efficiency and high cost; 3. During the pressing process of traditional wafer chamfering grinding heads, the abrasive layer is prone to fall off due to the small contact area between the base and the abrasive layer and the low bonding strength. The abrasive layer has a large resistance during the pressing and demolding process, resulting in uneven density and low strength of the abrasive layer, which in turn causes large deviations in the life of each slot or head breakage. The abrasive layer of the wafer chamfering grinding head for notch chamfering has the characteristics of large aspect ratio (blank diameter φ3.8~4.5mm, length 10-15mm, aspect ratio 4), and its diameter is smaller than that of traditional wafer chamfering grinding heads. During the pressing process, the lateral pressure generated by the mold wall and the abrasive layer has a great influence on the distribution of the abrasive layer density during the pressing process. It is necessary to find a way to reduce the uneven density of the abrasive layer caused by the lateral pressure of the mold wall and the abrasive layer.

[0005] The traditional pressing method is cold pressing with a mold. During the pressing process, as the volume of the powder decreases, the matrix and the lower pressure head will move accordingly. During the movement, friction is generated, and a certain lateral pressure is generated laterally on the mold wall, which causes a large amount of internal stress (lateral pressure) to accumulate in the pressed blank, resulting in pressure lines on the blank after pressing (such as Figure 4), resulting in uneven density, especially for powders of different particle sizes in the patent, the side pressures generated by the three types of powders (transition layer, efficiency station layer, quality station layer) and the cross wall of the mold during the compression process are inconsistent, forming a more serious pressure difference in density between the three types of powders, which in turn causes irreversible gradient differences in the density and strength of the green body.

[0006] At the same time, traditional molds (such as Figure 6 ) can only be pressed one at a time, and during the demolding process, the demolding force needs to overcome the static friction (residual side pressure) and dynamic friction between the green compact and the mold wall. The static friction and dynamic friction of the three powder compacts with different properties are different, resulting in problems such as increased volume and rebound of the powder compact. In severe cases, it will cause problems such as green compact falling and delamination.

[0007] During the demoulding process, the demoulding force needs to overcome the static friction and dynamic friction between the green compact and the cross wall to make the green compact come out of the mold cavity, which causes the green compact size to increase and the density to change after demoulding. In severe cases, the abrasive layer may fall off and become loose. At the same time, the traditional pressing process adopts a single pressing method, which is inefficient and not suitable for mass production. Summary of the invention

[0008] The purpose of the present invention is to address the deficiencies of the above-mentioned prior art and to provide a wafer positioning groove chamfering grinding head and a manufacturing method for wafer Notch cut chamfering, so as to achieve uniform density and efficient production of straight shank, wafer chamfering grinding heads with large aspect ratio and solve the problems of poor surface quality and stress concentration of wafer Notch cut.

[0009] In order to solve the above technical problems, the technical solution adopted by the present invention is: A wafer positioning groove chamfering grinding head for wafer Notch cut chamfering comprises a handle, a transition layer, a fine grinding layer and a rough grinding layer, and is pressed by a conical detachable split mold. The conical detachable split mold includes a sintering protective cover, an inner cone mold sleeve, a split outer cone porous mold cavity and upper and lower pressure heads, and the split outer cone porous mold cavity is surrounded by a plurality of sub-conical bodies, and the outer cone surface and the inner cone mold sleeve have the same taper, and a plurality of semi-cylindrical mold cavities are arranged between adjacent sub-cones. The semi-cylindrical mold cavities between adjacent sub-cones are combined to form a plurality of complete cylindrical mold cavities and are used to place the upper and lower pressure heads and the abrasive layer.

[0010] A method for manufacturing a wafer positioning groove chamfering grinding head for wafer Notch cut chamfering comprises the following steps: (1) Prepare the powder to be pressed and divide it into components of corresponding weight according to the needs, including transition layer powder, coarse grinding layer powder, and fine grinding layer powder; (2) Treat the substrate surface, remove oil stains, and evenly apply flux; (3) Clean the conical detachable split mold to remove surface oil and impurities, apply nano-silicon dioxide in the cavity of the split outer cone porous mold cavity, and then assemble the split outer cone porous mold cavity into a complete cone in sequence, and place the cone in the inner cone mold sleeve, and then use a copper rod to evenly vibrate at multiple points to ensure that the cone surface is complete; (4) Place the lower pressure head in the mold cavity, and then evenly load the fine grinding layer powder, coarse grinding layer powder, and transition layer powder into the mold cavity in order. Each layer of powder must be compacted and flattened, and then the substrate is loaded into the mold cavity, and the part with flux is flat with the transition layer; (5) Place the mold on the press, connect the ultrasonic vibrator, set the ultrasonic parameters and the press pressure curve, and perform the pressing work; (6) After the pressing is completed, remove the ultrasonic vibrator, put on the sintering protective cover and place it in a high-temperature furnace for protective gas sintering; (7) After sintering is completed, use a copper rod to gently vibrate and remove the inner cone mold sleeve, separate the outer cone porous mold cavity, take out the pressed blank, and complete the blank firing work.

[0011] A method for manufacturing a wafer positioning groove chamfering grinding head for wafer Notch cut chamfering, wherein the assembly process of a conical detachable split mold comprises the following steps: a. Assemble multiple vertebral bodies with the same taper direction into an outer cone multi-hole mold cavity, and place them in the inner cone mold sleeve; b. Then place the pressure head in the cavity, and throw the abrasive layer and transition layer onto the pressure head in the cavity in sequence. c. Then place the upper pressing head on the transition layer and assemble it, and then press and sinter it; d. After sintering, first remove the inner cone mold sleeve, and the multiple cones will automatically separate, and the pressed blank will be "peeled off" without pressure.

[0012] The sintered protective sleeve is made of high-strength cast iron.

[0013] The inner cone die sleeve is made of special forged high-quality steel with a hardness of ≥65HRC.

[0014] The sub-cones are provided with four parts.

[0015] The size of the super-hard abrasive in the fine grinding layer is smaller than that of the super-hard abrasive in the rough grinding layer.

[0016] The beneficial effects of the present invention are: (1) The present invention discloses a wafer positioning groove chamfering grinding head and a manufacturing method for wafer Notch cut chamfering, which is pressed by a conical detachable split mold, wherein the conical detachable split mold comprises a sintering protective sleeve, an inner cone mold sleeve, a split outer cone multi-porous mold cavity and upper and lower pressing heads, and the split outer cone multi-porous mold cavity is formed by enclosing a plurality of sub-cones, and the taper of the outer cone surface and the inner cone mold sleeve is consistent, and a plurality of semi-cylindrical mold cavities are arranged between adjacent sub-cones, and the semi-cylindrical mold cavities between adjacent sub-cones are combined to form a plurality of complete cylindrical mold cavities and are used for Placing the upper and lower pressure heads and abrasive layers can realize the precision chamfering process of the Notch cut, and solve the problems of uneven density, large strength deviation, uneven life of each groove, grinding breakage, low efficiency of single pressing, low yield and high cost of large aspect ratio, straight shank and wafer chamfer grinding heads. The design, production and manufacturing of large aspect ratio, straight shank and wafer chamfer grinding heads with uniform density and high efficiency are realized, which solves the problems of poor surface quality and stress concentration of wafer Notch cut, and realizes low damage and high efficiency precision processing of wafer Notch mouth.

[0017] (2) The "peanut peeling" demolding method is adopted to "throw away" the demolding force, that is, the blank is thrown away after traditional pressing and the stamping demolding method is adopted. After the blank is pressed and formed, the outer shell of the conical detachable mold is removed, which can create a gap between the blank and the mold contact surface, "peel off" the mold "shell" of the blank, and "throw away" the demolding force, avoiding the problems of abrasive layer falling off, loosening, and secondary changes in the density of the pressed blank. At the same time, the single-time multiple pressing method is adopted to improve the pressing efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the grinding head structure of the present invention; Figure 2 It is a schematic diagram of the structure of multiple stations; Figure 3 It is a schematic diagram of the pressure gradient of conventional pressing; Figure 4 It is a schematic diagram of traditional suppression; Figure 5 Schematic diagram of the distribution of the abrasive layer of the present invention; Figure 6 is a cross-sectional view of a conical detachable split mold; Figure 7 It is a top view of the conical detachable split mold; Figure 8 It is a structural schematic diagram of the inner cone die sleeve; Fig. 9 It is a schematic diagram of the structure of a split outer cone porous mold cavity; Fig.10 is a schematic diagram of an ultrasonic vibration mold; Fig.11 It is a schematic diagram of protective gas sintering; Fig.12 is a schematic diagram of the pressing pressure gradient of the present invention; Fig.13 It is a structural schematic diagram of the upper pressure head; Fig.14 It is a schematic diagram of the structure of the lower pressure head; Fig.15 This is the state diagram of wafer grinding in the traditional process; Fig.16 It is a wafer grinding state diagram of the present invention. DETAILED DESCRIPTION

[0019] The following is a description of the implementation of the present invention by means of specific embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

[0020] The present invention provides a wafer positioning groove chamfering grinding head for wafer Notch cut chamfering and a manufacturing method thereof, such as Figures 1 to 16 shown.

[0021] A wafer positioning groove chamfering grinding head for wafer Notch cut chamfering comprises a handle 11, a transition layer 12, a fine grinding layer 13 and a coarse grinding layer 14, and is pressed by a conical detachable split mold, and the conical detachable split mold comprises a sintering protective cover 21, an inner cone mold sleeve 22, a split outer cone porous mold cavity 23 and upper and lower pressure heads, and the split outer cone porous mold cavity 23 is surrounded by a plurality of sub-cones 231, and the taper of the outer cone surface and the inner cone mold sleeve 22 are consistent, and a plurality of semi-cylindrical mold cavities are arranged between adjacent sub-cones, and the semi-cylindrical mold cavities between adjacent sub-cones are combined to form a plurality of complete cylindrical mold cavities 24 for placing upper and lower pressure heads and an abrasive layer.

[0022] A method for manufacturing a wafer positioning groove chamfering grinding head for wafer Notch cut chamfering comprises the following steps: (1) Prepare the powder to be pressed and divide it into components of corresponding weight according to the needs, including transition layer powder, coarse grinding layer (efficiency layer) powder, and fine grinding layer (quality layer) powder; (2) Treat the substrate surface, remove oil stains, and evenly apply flux 15; (3) Clean the conical detachable split mold to remove surface oil and impurities, apply nano-silicon dioxide in the cavity of the split outer cone porous mold cavity 23, and then assemble the split outer cone porous mold cavity 23 into a complete cone in sequence, and place the cone in the inner cone mold sleeve 22, and then use a copper rod to evenly vibrate at multiple points to ensure that the cone surface is complete; (4) Place the lower pressure head 32 in the mold cavity, and then evenly load the fine grinding layer powder, the coarse grinding layer powder, and the transition layer powder into the mold cavity in sequence. Each layer of powder must be compacted and flattened, and then the substrate is loaded into the mold cavity, and the part with the flux is flat with the transition layer; (5) Place the mold on the press, connect the ultrasonic vibrator 4, set the ultrasonic parameters and the press pressure curve, and perform the pressing work; (6) After the pressing is completed, the ultrasonic vibrator 4 is removed, the sintering protective cover 21 is put on, and the furnace is placed in a high-temperature furnace for sintering with protective gas; (7) After sintering is completed, use a copper rod to gently vibrate and remove the inner cone mold sleeve 22, separate the outer cone porous mold cavity 23, take out the pressed blank, and complete the blank firing work.

[0023] In this embodiment, the sintering protection cover 21 is made of high-strength cast iron, mainly to give a tightening force to the conical mold during the mold sintering process, reduce the effect of the conical mold expansion, and avoid the problem of deformation of the abrasive layer caused by mold expansion; the inner cone mold cover 22 is made of special forged high-quality steel that is pressure-resistant, high-strength, and wear-resistant, with a hardness of ≥65HRC. It has the function of resisting pressing pressure and maintaining the structure of the split outer cone porous mold cavity 23. Its inner cone surface and the outer cone surface of the split outer cone porous mold cavity 23 cooperate to ensure the integrity of the mold combination during the pressing process.

[0024] The split outer cone porous mold cavity 23 is composed of four blocks, each of which is a quarter cone. The taper of the outer cone and the inner cone mold sleeve 22 is consistent to ensure that the volume and shape of the mold cavity remain unchanged during the pressing process. The mold cavity is distributed with several semi-cylindrical mold cavities. When the four mold cavities are combined together, multiple complete cylindrical mold cavities are formed. The cylindrical mold cavity is used to place the upper and lower pressure heads and the abrasive layer.

[0025] The assembly process of the conical removable split mold includes the following steps: a. Assemble four vertebral bodies with the same taper direction to form an outer cone porous mold cavity 23, and place it in the inner cone mold sleeve 22; b. Then place the pressure head 32 in the cavity, and throw the abrasive layer and the transition layer onto the pressure head 32 in the cavity in sequence. c. Then, the upper pressing head 31 is placed on the transition layer and assembled, and then pressed and sintered; d. After sintering and forming, the inner cone mold sleeve 22 is first removed, and the four sub-cones 231 are automatically separated, and the pressed blank is "peeled" without pressure.

[0026] The size of the super-hard abrasive in the fine grinding layer is smaller than that of the super-hard abrasive in the rough grinding layer.

[0027] More specifically, a large aspect ratio, straight shank wafer chamfering grinding head includes a shank, a transition layer, an efficiency station, and a quality station, such as Figure 1 As shown, the shank is used to connect the machine tool and the abrasive layer to ensure that the rotation accuracy of the abrasive layer meets customer requirements; the transition layer is used to connect the shank and the abrasive layer; the efficiency station is used to remove large excesses while ensuring the smallest damaged layer, chipping, shell cracks and other cutting depressions; the quality station is used to repair scratches and other cutting depressions after rough grinding to achieve the required groove accuracy and surface quality.

[0028] The contact area between the abrasive layer and the substrate is about 11~14mm 2 , the contact area is small, and the conventional sintering process cannot meet the conditions for the abrasive layer and the substrate to form a metal bond to form a strong bonding strength.

[0029] The present invention adopts the method of adding a transition layer, and the transition layer adopts fine copper powder, nickel powder, and silver powder. Because the composition of the transition layer is similar to that of the abrasive layer binder, it is easy to form a strong sintering strength during the sintering process. At the same time, there are strong active metal components in the transition layer, which can also form a strong bonding strength with the substrate during sintering. Protective gas sintering is adopted, and the surface treatment does not need oxygen. Nitrogen, hydrogen and other gases are used as protective gases, which can ensure that the bonding between the abrasive layer and the metal substrate reaches a metal bond.

[0030] In addition, a special soldering flux is applied on the surface of the substrate. The main components of the soldering flux are composite fluoroborate, composite borate, activator, etc. During the hot pressing and sintering process of the wafer chamfering grinding head blank, the soldering flux can remove the oxidant on the metal surface, play a role in metal infiltration, assist heat conduction, remove oxides, reduce the surface tension of the welded material, remove oil stains on the surface of the welded material, increase the welding area, and prevent re-oxidation. The metal bond is formed between the substrate and the non-layer during the sintering process, ensuring the bonding strength of the substrate and the abrasive layer. Figure 5 shown.

[0031] In order to achieve maximum efficiency by matching the process of the efficiency station and provide a better surface quality foundation for the quality station, the efficiency station and the quality station adopt a multi-dimensional cross-grain size and cross-crystal composite layout of superhard abrasives according to the characteristics of the station.

[0032] Efficiency station: In view of the requirements of large margin, large feed rate, and fast cutting speed faced by the efficiency station, higher requirements are put forward for the sharpness, cutting edge height and continuous cutting ability of super-hard abrasives. The present invention adopts super-hard abrasive 1 with larger particles, many sharp crystal surfaces, and easy grinding and crushing to produce new cutting edges. The fallen abrasive debris is also involved in the grinding process to improve the surface quality of grinding. At the same time, in order to take into account a better surface quality foundation, the scratch depth of the wafer surface of super-hard abrasive 1 during the grinding process is measured and counted, and super-hard abrasive 2 is preferred. Super-hard abrasive 2 is smaller in size than super-hard abrasive, but has better crystal form and strength. It can repair the rough surface of super-hard abrasive 1 after grinding to a certain extent, remove the high points and deep grooves produced by super-hard abrasive 1 grinding, and then improve the surface quality, providing a surface quality foundation for the processing of the quality station.

[0033] Quality station: The quality station also adopts the form of multi-dimensional cross-particle size and cross-crystal type composite distribution, and quantifies the customer's demand for processing surface quality. First, select suitable superhard abrasive 3 to further repair the rough surface quality after grinding in the efficiency station. Superhard abrasive 3 needs to have a good crystal form and a sharp cutting edge. At the same time, the grinding surface condition and the final surface requirements of the efficiency station are taken into account. The appropriate particle size is selected to ensure the particle size of the superhard abrasive, which can effectively remove the rough surface left by the efficiency station and form a uniform and well-rough surface quality. The introduction of superhard material 4 in the quality station can be used to optimize the surface quality after grinding of superhard abrasive 3 to meet the quality requirements of the workpiece. Superhard material 4 must have a good particle size concentration and suitable particle size and complete crystal form.

[0034] The manufacturing method of the present invention is used to press a wafer chamfering grinding head for wafer Notch chamfering using 800+2000# as main abrasive.

[0035] During the processing, a layer of paste flux is evenly applied to the upper pressure head (substrate), of which the non-layer design thickness is 2mm, the coarse grain size is 800#, of which A crystal type diamond 800# accounts for 90%, B crystal type 1500# diamond accounts for 10%; fine grain C crystal type 2000# diamond accounts for 80%, D crystal type 2500# diamond accounts for 20#.

[0036] Variable power ultrasonic vibrator, set working frequency 15K, time 10S; 18K, 15S; 20K, 30S; after pressing, it is sintered using a 680° special sintering curve.

[0037] A special tensile testing machine was used for comparative testing. The bonding strength of the wafer chamfering grinding head for wafer Notch chamfering after pressing of the present invention is much greater than that of the chamfering grinding head made by the traditional method, as shown in Table 1. After Notch grinding of 8-inch silicon wafer with a thickness of 800 μm, compared with the wafer chamfering grinding head for wafer Notch chamfering commonly used by customers, it was found that the surface quality was improved. Fig.15 and Fig.16 As shown, according to statistics, the life span is increased by about 15% and the efficiency is increased by about 12%.

[0038] If the terms "first" and "second" are used in the present invention to limit components, those skilled in the art should know that the use of "first" and "second" is only to facilitate the description of the present invention and simplify the description, and the above terms have no special meaning.

[0039] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. The present invention may be subject to various changes and improvements without departing from the spirit and scope of the present invention. These changes and improvements fall within the scope of the invention claimed for protection. The scope of protection claimed for the present invention is defined by the attached claims and their equivalents.

[0040] In the description of the present invention, it is necessary to understand that the terms "front", "rear", "left", "right", "center", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the protection content of the present invention.

Claims

1. A wafer positioning groove chamfering grinding head for wafer Notch cut chamfering, characterized in that: It includes a handle, a transition layer, a fine grinding layer and a coarse grinding layer, and is pressed using a conical detachable split mold. The conical detachable split mold includes a sintering protective cover, an inner cone mold sleeve, a split outer cone porous mold cavity and upper and lower pressure heads, and the split outer cone porous mold cavity is surrounded by a plurality of sub-conical bodies, and the outer cone surface and the inner cone mold sleeve have the same taper, and a plurality of semi-cylindrical mold cavities are arranged between adjacent sub-cones. The semi-cylindrical mold cavities between adjacent sub-cones are combined to form a plurality of complete cylindrical mold cavities and are used to place the upper and lower pressure heads and the abrasive layer.

2. The method for manufacturing a wafer positioning groove chamfering grinding head for wafer Notch chamfering according to claim 1, characterized in that: The following steps are involved: (1) Prepare the powder to be pressed and divide it into components of corresponding weight according to the needs, including transition layer powder, coarse grinding layer powder, and fine grinding layer powder; (2) Treat the substrate surface, remove oil stains, and evenly apply flux; (3) Clean the conical detachable split mold to remove surface oil and impurities, apply nano-silicon dioxide in the cavity of the split outer cone porous mold cavity, and then assemble the split outer cone porous mold cavity into a complete cone in sequence, and place the cone in the inner cone mold sleeve, and then use a copper rod to evenly vibrate at multiple points to ensure that the cone surface is complete; (4) Place the lower pressure head in the mold cavity, and then evenly load the fine grinding layer powder, coarse grinding layer powder, and transition layer powder into the mold cavity in order. Each layer of powder must be compacted and flattened, and then the substrate is loaded into the mold cavity, and the part with flux is flat with the transition layer; (5) Place the mold on the press, connect the ultrasonic vibrator, set the ultrasonic parameters and the press pressure curve, and perform the pressing work; (6) After the pressing is completed, remove the ultrasonic vibrator, put on the sintering protective cover and place it in a high-temperature furnace for protective gas sintering; (7) After sintering is completed, use a copper rod to gently vibrate and remove the inner cone mold sleeve, separate the outer cone porous mold cavity, take out the pressed blank, and complete the blank firing work.

3. The method for manufacturing a wafer positioning groove chamfering grinding head for wafer Notch chamfering according to claim 1, characterized in that: The assembly process of the conical removable split mold includes the following steps: a. Assemble multiple vertebral bodies with the same taper direction into an outer cone multi-hole mold cavity, and place them in the inner cone mold sleeve; b. Then place the pressure head in the cavity, and throw the abrasive layer and transition layer onto the pressure head in the cavity in sequence. c. Then place the upper pressing head on the transition layer and assemble it, and then press and sinter it; d. After sintering, first remove the inner cone mold sleeve, and the multiple cones will automatically separate, and the pressed blank will be "peeled" without pressure.

4. A method for manufacturing a wafer positioning groove chamfering grinding head for wafer Notch chamfering according to any one of claims 1 to 3, characterized in that: The sintered protective sleeve is made of high-strength cast iron.

5. The method for manufacturing a wafer positioning groove chamfering grinding head for wafer Notch chamfering according to claim 4, characterized in that: The inner cone die sleeve is made of special forged high-quality steel with a hardness of ≥65HRC.

6. The wafer positioning groove chamfering grinding head for wafer notch chamfering according to claim 4, characterized in that: The sub-cones are provided with four parts.

7. The wafer positioning groove chamfering grinding head for wafer notch chamfering according to claim 4, characterized in that: The size of the super-hard abrasive in the fine grinding layer is smaller than that of the super-hard abrasive in the rough grinding layer.

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