CN112621551B

CN112621551B - Ultra-precise wafer grinding equipment capable of being positioned quickly

Info

Publication number: CN112621551B
Application number: CN202011512291.4A
Authority: CN
Inventors: 许剑锋; 张建国; 郑正鼎; 汪凯; 刘明川; 陈肖; 肖峻峰
Original assignee: Huazhong University of Science and Technology
Current assignee: Huazhong University of Science and Technology
Priority date: 2020-12-19
Filing date: 2020-12-19
Publication date: 2021-10-08
Anticipated expiration: 2040-12-19
Also published as: CN112621551A

Abstract

The invention belongs to the field of ultra-precision machining, and particularly discloses ultra-precision wafer grinding equipment capable of quickly positioning, which comprises a quick positioning device and a grinding device, wherein the quick positioning device is used for quickly positioning a wafer and comprises a rotary power unit, a vacuum adsorption unit and a positioning ring, the vacuum adsorption unit is arranged on the rotary power unit and is driven to rotate by the rotary power unit, the vacuum adsorption unit comprises a vacuum chuck and a vacuum generator connected with the vacuum chuck, and the vacuum chuck is provided with a plurality of adsorption holes which are uniformly distributed; the positioning ring is sleeved outside the vacuum chuck and covers a part of the adsorption hole so as to be adsorbed on the vacuum chuck under the action of the vacuum generator, and the inner diameter of the positioning ring is matched with the outer diameter of the wafer to be positioned; the grinding device is arranged beside the quick positioning device and is used for grinding the positioned wafer. The invention can realize the ultra-precise grinding of the wafer and has the advantages of high positioning precision, high grinding precision, good grinding quality and the like.

Description

Ultra-precise wafer grinding equipment capable of being positioned quickly

Technical Field

The invention belongs to the field of ultra-precision machining, and particularly relates to ultra-precision wafer grinding equipment capable of being positioned quickly.

Background

The wafer is a silicon wafer used for manufacturing a silicon semiconductor integrated circuit, the requirement is high, the requirement on cutting precision is high, and in order to improve the processing speed and precision of the wafer in the processing process, the wafer needs to be positioned quickly and accurately, so that the quick and accurate positioning of the wafer is very important for improving the processing efficiency of the wafer, and the wafer is subjected to subsequent grinding processing after being positioned.

For wafer positioning, the wafer is not easy to take and place because the wafer is thin, and the wafer is easy to crack after collision. In the traditional wafer positioning method and device, the conditions that the positioning time is too long, the positioning accuracy is difficult to ensure or the wafer is damaged in the positioning process often occur, so that the high-accuracy processing efficiency of the wafer is low. Therefore, further research is needed in wafer positioning to achieve fast and accurate wafer positioning.

For the grinding process, there are mainly ultrasonic auxiliary grinding and laser auxiliary grinding at present, and in the ultrasonic grinding aspect, for example, patent CN206998465U discloses a two-dimensional ultrasonic vibration abrasive belt grinding device for grinding hard and brittle materials, patent CN110653668A discloses a three-dimensional variable parameter rotation ultrasonic grinding device for hard and brittle materials for automobiles, and patent CN108637802A discloses an ultrasonic auxiliary grinding device. However, the conventional ultrasonic grinding apparatuses cannot be applied to grinding of wafers, mainly because of the following reasons: 1) the grinding tool is coaxially arranged with the transmission shaft, the ultrasonic vibration is along the axial direction of the transmission shaft, the ultrasonic vibration grinding only can be realized in the axial direction, when the wafer is subjected to the cutting, edging and other grinding processes, the grinding wheel is generally vertical to the surface of the wafer, the radial ultrasonic vibration needs to be applied, and the conventional axial ultrasonic vibration cannot meet the requirement of wafer grinding; 2) the grinding device is generally large in size, cannot meet the requirement of high-speed (generally 20000rpm-30000rpm) grinding of the wafer, and during high-speed grinding, the large-size grinding device is difficult to keep dynamic balance, has poor grinding quality and even can cause adverse consequences such as wafer breakage. In the aspect of laser-assisted grinding, CN110449995A discloses a laser-assisted grinding device and method for free-form surface grinding, however, the grinding needle of the grinding device is often used for processing free-form surface micro-disc and blade parts, and the grinding needle only has a local area interacting with the workpiece for processing, so it is not suitable for processing large-caliber wafers efficiently and in large quantities for a long time; CN109605138A discloses an embedded laser-assisted ultra-precise cylindrical grinding device and a working method thereof, however, the device can only realize intermittent laser irradiation, the laser utilization efficiency is very low, and the intermittent laser irradiation can cause the grinding edge of the grinding wheel to have inconsistent grinding of a laser area and a non-laser area to a workpiece, which causes uneven grinding, greatly affects the grinding quality, and is therefore difficult to be applied to ultra-precise grinding of wafers.

Therefore, for wafer processing, the existing positioning and grinding devices are not suitable for wafers or have some defects, so that certain research and design needs to be carried out in the field to obtain a set of equipment capable of realizing rapid and accurate positioning of wafers and ultra-precise grinding of wafers.

Disclosure of Invention

Aiming at the defects or the improvement requirements of the prior art, the invention provides the ultra-precise wafer grinding equipment capable of quickly positioning, which can realize the quick and precise positioning of the wafer and the ultra-precise grinding processing of the wafer after the wafer is positioned through the design of the positioning device and the grinding device, and has the advantages of high grinding efficiency, good quality, high precision and the like.

In order to achieve the purpose, the invention provides ultra-precise wafer grinding equipment capable of quickly positioning, which comprises a quick positioning device and a grinding device, wherein the quick positioning device is used for quickly positioning a wafer and comprises a rotary power unit, a vacuum adsorption unit and a positioning ring, the vacuum adsorption unit is arranged on the rotary power unit and can be driven to rotate by the rotary power unit, the vacuum adsorption unit comprises a vacuum chuck and a vacuum generator connected with the vacuum chuck, and the vacuum chuck is provided with a plurality of adsorption holes uniformly distributed; the positioning ring is sleeved outside the vacuum chuck and covers a part of the adsorption hole, so that the positioning ring is adsorbed on the vacuum chuck under the action of the vacuum generator, and the inner diameter of the positioning ring is adapted to the outer diameter of the wafer to be positioned; the grinding device is arranged beside the quick positioning device and used for grinding the positioned wafer.

Preferably, the grinding device is a laser in-situ auxiliary grinding device, which comprises a grinding module and a laser generation module, wherein the grinding module is used for grinding a wafer and comprises a grinding spindle, a transparent grinding wheel and a spindle motor, the transparent grinding wheel and the spindle motor are arranged at two ends of the grinding spindle, and the spindle motor is used for driving the grinding spindle and the transparent grinding wheel thereon to rotate so as to grind the wafer by using the circumference of the transparent grinding wheel; the laser generating module is arranged in the middle of the grinding module and used for emitting laser which is superposed with the axis of the grinding spindle, enabling the laser to penetrate through the transparent grinding wheel to be emitted along the radial direction of the transparent grinding wheel and then focused on a part to be ground of the wafer, and therefore laser in-situ auxiliary grinding processing of the wafer is achieved.

Preferably, the laser generation module includes a laser, a laser path and a reflector, the laser is mounted on the spindle motor, the laser path passes through the spindle motor and the grinding spindle and extends into the transparent grinding wheel, one end of the laser path located at the spindle motor is connected to the laser, one end of the laser path extending to the transparent grinding wheel is connected to the reflector, and the laser emitted by the laser irradiates the reflector through the laser path and is reflected by the reflector and then is emitted along the radial direction of the transparent grinding wheel.

Preferably, the laser passage is a slender light glass tube, and a hole is formed in the tube wall of the glass tube at a position corresponding to the laser emitting position; preferably, the wafer grinding device further comprises a clamping module, the clamping module comprises a transparent locking bolt and an end cover, the transparent locking bolt is sleeved outside one end of the laser channel, the end cover extends to the outside of one end of the transparent grinding wheel, the transparent locking bolt is connected with the grinding spindle, the transparent grinding wheel is sleeved outside the transparent locking bolt, and the end cover is located between the transparent locking bolt and the transparent grinding wheel and used for tightly pressing the transparent grinding wheel.

As a further preferred, the transparent locking bolt is made of a transparent matrix resin doped with a high-strength resin, wherein the mass percentage of the transparent matrix resin is more than 98%, and the mass percentage of the high-strength resin is less than 2%; preferably, the transparent grinding wheel is made of transparent matrix resin, the transparent matrix resin is doped with high-strength resin, and the mass ratio of the transparent matrix resin to the high-strength resin is (95% -98%): (5% -2%), the transparent abrasive grain is also evenly distributed in the circumferential surface of the transparent grinding wheel.

Further preferably, the transparent matrix resin is one or more of polymethyl methacrylate, allyl diglycol carbonate and polycarbonate, and the high-strength resin is one or more of polyvinyl alcohol fiber resin and epoxy resin; preferably, the distribution thickness of the light-transmitting abrasive particles in the circumferential surface of the transparent grinding wheel is 2 mm-3 mm, and the light-transmitting abrasive particles are made of artificial diamond.

Preferably, the grinding device is an ultrasonic vibration auxiliary grinding device, which comprises a fixing unit, a grinding unit, a vibration unit and a spindle motor for driving the three units to rotate together, wherein the fixing unit is mounted on an output shaft of the spindle motor and used for mounting and fixing the grinding unit and the vibration unit; the grinding unit is arranged at one end of the fixing unit, which is far away from the spindle motor, and comprises an ultrasonic grinding wheel, the ultrasonic grinding wheel is arranged on a vibration transmission disc, and is clamped by a grinding wheel clamp, and the vibration transmission disc is arranged on the fixing unit; the vibration unit comprises a piezoelectric driving module and a non-contact type electric energy transmission module, wherein the non-contact type electric energy transmission module is arranged in one end, close to the spindle motor, of the fixing unit and connected with the piezoelectric driving module to provide an alternating electric field for the piezoelectric driving module; the piezoelectric driving module is arranged in the vibration transmission disc and used for converting an alternating current signal into a vibration signal and transmitting the vibration to the vibration transmission disc, and the vibration transmission disc and the piezoelectric driving module generate resonance, so that the ultrasonic grinding wheel generates high-frequency vibration along the radial direction while rotating.

Preferably, the fixing unit includes a spindle end plate and a base, the spindle end plate is sleeved on an output shaft of the spindle motor and locked by a locking bolt, and the base is sleeved outside the spindle end plate and fixed on the spindle motor.

Preferably, the non-contact power transmission module includes a power transmitting mechanism and a power receiving mechanism, and the power transmitting mechanism and the power receiving mechanism are respectively embedded in the base and the spindle end disk.

Preferably, the electric energy transmitting mechanism and the electric energy receiving mechanism are both composed of a coil winding and a fixed magnetic core, and an ultrasonic frequency oscillation electric signal is generated by an ultrasonic power supply connected to the electric energy transmitting mechanism, so that the fixed magnetic core on the electric energy transmitting mechanism generates a high-frequency alternating magnetic field, and further the coil winding on the electric energy receiving mechanism generates a same-frequency induced electromotive force acting on the piezoelectric driving module.

Preferably, a round nut is further mounted on the spindle end disc and used for pressing the grinding wheel clamp.

Preferably, the vibration transmission disc is provided with annular grooves at intervals; preferably, the piezoelectric driving module is a circular ring piezoelectric ceramic, which is polarized in the radial direction, and electrodes are laid on the inner hole surface and the outer ring surface, and under the continuous power supply of the non-contact power transmission module, a radial electric field is generated between the electrodes on the inner hole surface and the outer ring surface of the piezoelectric driving module, and high-frequency vibration in the radial direction is generated through the periodic change of the electric field frequency.

Preferably, the ultrasonic grinding wheel is a diamond abrasive wheel, and the spindle motor is an air spindle motor.

Preferably, the vacuum chuck is in a stepped cylindrical shape, a large end of the vacuum chuck is connected with the rotary power unit and communicated with the vacuum generator through a pipeline, the adsorption holes are formed in a small end of the vacuum chuck and communicated with the pipeline, and a hole for mounting the mass block is further formed in the large end of the vacuum chuck.

As further preferred, the holding ring is split type structure, and it is formed by two ring structure combinations that the structure is the same, the inner wall of ring structure and the lateral wall interference fit of vacuum chuck tip, this ring structure still is provided with along its radial extension's annular boss, and this annular boss is laminated with the upper surface of vacuum chuck tip, and its internal diameter equals with the external diameter of wafer.

Preferably, the suction holes are annularly distributed around the center of the vacuum chuck, and the suction holes are designed to satisfy the following conditions: the radius of the wafer is larger than that of the adsorption hole area covered by the wafer by more than 0.5mm, and the diameter of the adsorption is designed to be 2-3 mm.

As a further preference, the vacuum chuck is made of stainless steel and the positioning ring is made of a titanium alloy.

As a further preferred, the rotary power unit includes a spindle motor and a rotary spindle connected thereto, the vacuum generator is mounted on the spindle motor, and the vacuum chuck is mounted on the rotary spindle.

Generally, compared with the prior art, the above technical solution conceived by the present invention mainly has the following technical advantages:

1. according to the invention, through the design of the whole structure of the grinding equipment, the wafer workpiece can be quickly and accurately positioned, and the ultra-precise grinding of the wafer can be realized, so that the grinding machine has the advantages of high positioning precision, high grinding precision, good grinding quality and the like.

2. According to the invention, through the design of the whole structure of the positioning device, the wafer can be quickly and accurately positioned, the time of the wafer centering step in the traditional installation process is shortened, the damage caused by the wafer installation is avoided, meanwhile, the dynamic balance adjustment of the subsequent wafer workpiece is facilitated, the early preparation link of the wafer processing is greatly optimized, and the wafer processing efficiency is improved.

3. According to the invention, through the structural design of the vacuum chuck, effective adsorption of the positioning ring and the wafer can be realized, and through designing the vacuum chuck into a stepped cylindrical shape, interference of a processing tool such as a grinding wheel and the like with the processing tool can be prevented, and effective proceeding of subsequent grinding processing of the wafer is ensured.

4. The positioning ring is designed into a split structure, so that the positioning ring is conveniently and rapidly and accurately assembled on the vacuum chuck on one hand, and the wafer is conveniently taken down along the direction vertical to the rotating main shaft after being positioned on the other hand, the friction between the positioning ring and the wafer is avoided, and the wafer is prevented from being worn and cracked.

5. The invention also researches the specific design requirement and size of the adsorption hole, can effectively avoid the phenomenon that the edge of the wafer is damaged in the processing process due to the adsorption force of the adsorption hole, and ensures the quality of the wafer.

6. According to the invention, through the design of the integral structure of the laser auxiliary grinding device, laser emitted along the radial direction of the grinding wheel can be generated to focus on a grinding area to form laser in-situ auxiliary grinding, and the laser beam can not change along with the rotation of the grinding spindle and always irradiates on a specified position, so that the laser energy can be efficiently utilized, and the high-quality grinding of the wafer can be realized.

7. The laser irradiation device can enable laser to be emitted according to a specified path through the design of the laser generation module and irradiate at a specified position all the time, and can realize the adjustment of a laser irradiation area through the adjustment of the installation angle of the reflector.

8. The laser passage is designed into a slender light glass tube, the weight is light, the dynamic force generated during high-speed rotation is small, and the small holes are formed in the tube wall, so that laser can be directly emitted conveniently without loss.

9. Through the design of the clamping module, the grinding wheel can be conveniently and effectively assembled, and meanwhile, the grinding wheel can be conveniently replaced.

10. According to the invention, the grinding wheel is a transparent grinding wheel, the locking bolt is a transparent bolt, and through the design, laser from the laser generation module can penetrate through the transparent bolt and the transparent grinding wheel and focus on the grinding area of the grinding wheel to heat workpiece materials, so that laser in-situ auxiliary grinding processing is formed, diamond abrasive particle grinding of the workpiece is promoted, the grinding force is greatly reduced, the material removal rate is improved, and the grinding quality is improved.

11. The invention also researches and designs the preparation material and the material proportion of the grinding wheel, and the grinding wheel has high transparency, low laser loss and good strength, thereby realizing the effective grinding of the wafer.

12. The invention also researches and designs the preparation material and the material proportion of the locking bolt, and the locking bolt has higher transmittance, reduces the laser loss, improves the toughness and prolongs the service life through the design.

13. The laser auxiliary grinding device has the characteristics of small whole volume, miniaturization and light weight, can keep dynamic balance under the high-speed rotation of 20000rpm-30000rpm, and is very suitable for the ultra-precise grinding processing of hard and brittle wafers.

14. According to the invention, through the design of the whole structure of the ultrasonic vibration grinding device, the ultrasonic vibration direction of the grinding device can be distributed along the radial direction of the grinding wheel, so that the circumference of the ultrasonic grinding wheel is utilized to carry out ultra-precision processing on the wafer, and high-precision scribing and edge grinding processing of the wafer can be realized.

15. According to the invention, through the structural design of the fixing unit, the grinding unit and the vibration unit can be effectively assembled on the spindle motor, and the rotation of the output shaft of the spindle motor is utilized to realize the high-speed rotation of the grinding unit, the vibration unit and the spindle motor.

16. According to the invention, through the structural design of the vibration unit, the ultrasonic vibration can be effectively generated, and the ultrasonic vibration is ensured to be distributed along the radial direction of the grinding wheel, so that the high-frequency vibration is generated on the wafer while the grinding wheel rotates at a high speed.

17. According to the invention, through the design of the grinding wheel clamp and the vibration transmission disc, the grinding wheel can be effectively clamped, so that the axis of the grinding wheel is superposed with the axis of the spindle motor, the grinding action of the wafer is carried out by utilizing the circumferential surface of the grinding wheel during grinding, and the ultrasonic vibration direction is distributed along the radial direction of the grinding wheel, namely is vertical to the surface of the wafer, so that the processes of scribing, edging and the like of the wafer are realized.

18. According to the invention, through the design of the non-contact type electric energy transmission module, electric energy can be better transmitted to the piezoelectric driving module, so that the ultrasonic grinding wheel generates radial vibration, the ultrasonic vibration auxiliary grinding of a wafer is realized, the grinding force in the wafer grinding process is effectively reduced, the cooling effect of abrasive particles on the grinding wheel is improved, the wafer processing quality is further improved, and the service life of the grinding wheel is prolonged.

19. According to the invention, through polarization treatment of the piezoelectric driving module, a radial electric field can be generated in the piezoelectric driving module, and high-frequency vibration in the radial direction is generated through periodic change of the frequency of the electric field, so that the grinding wheel generates ultrasonic vibration in the radial direction.

20. The ultrasonic grinding wheel is connected with the vibration transmission disc and forms a resonance body with the piezoelectric driving module, so that the ultrasonic grinding wheel is not interfered by a spindle motor, the size and the structure of the spindle motor do not need to be considered in the design, the adaptability is strong, the manufacturing and the assembly are simple, and a common spindle motor can be transformed into an ultrasonic vibration grinding spindle.

21. The ultrasonic grinding device has the characteristics of small overall volume, miniaturization and light weight, can keep dynamic balance under the high-speed rotation of 20000rpm-30000rpm, and is very suitable for ultra-precise grinding processing of hard and brittle wafers.

Drawings

Fig. 1 is a schematic structural diagram of a first fast positioning ultra-precision wafer grinding apparatus according to an embodiment of the present invention;

FIG. 2 is a schematic structural diagram of a fast positioning apparatus provided in an embodiment of the present invention;

FIG. 3 is a cross-sectional view of a quick positioning device provided by an embodiment of the present invention;

FIG. 4 is a schematic structural diagram of a vacuum chuck provided in an embodiment of the present invention;

FIG. 5 is a schematic view of wafer workpiece positioning according to an embodiment of the present invention;

FIG. 6 is a schematic view of a wafer after positioning of the wafer workpiece is completed according to an embodiment of the invention;

FIG. 7 is a schematic view of a wafer workpiece of different dimensions after positioning is completed according to an embodiment of the present invention;

fig. 8 is an enlarged view of fig. 7 at a.

FIG. 9 is a schematic structural diagram of a laser in-situ auxiliary grinding apparatus provided in an embodiment of the present invention;

FIG. 10 is a schematic structural diagram of a laser in-situ auxiliary grinding device (for removing a transparent grinding wheel) provided by an embodiment of the invention;

FIG. 11 is a cross-sectional view of a laser in-situ assisted grinding apparatus provided in accordance with an embodiment of the present invention;

FIG. 12 is a cross-sectional view of a laser generating module provided by an embodiment of the present invention;

FIG. 13 is a cross-sectional view of a first rapidly positionable apparatus for grinding ultra-precise wafers according to an embodiment of the present invention;

fig. 14 is an assembly diagram of the wafer grinding apparatus and the ultra-precision machine tool according to the embodiment of the present invention.

Fig. 15 is a sectional view (spindle motor not cut) of an ultrasonic vibration assisted grinding apparatus provided in an embodiment of the present invention;

FIG. 16 is a schematic view of the assembly of a piezoelectric drive module, a vibration transmission disk and an ultrasonic grinding wheel provided in an embodiment of the present invention;

FIG. 17 is a schematic diagram of the vibration of the piezoelectric driving module and the ultrasonic grinding wheel provided in the embodiment of the present invention;

FIG. 18 is a schematic structural diagram of a second fast positioning ultra-precision wafer grinding apparatus according to an embodiment of the present invention;

FIG. 19 is a cross-sectional view of a second rapidly positionable apparatus for grinding ultra-precise wafers according to an embodiment of the present invention;

fig. 20 is a schematic diagram of wafer edge grinding and dicing by using a grinding wheel according to an embodiment of the present invention, in which (a) is a schematic diagram of edge grinding, and (b) is a schematic diagram of dicing.

The same reference numbers will be used throughout the drawings to refer to the same or like elements or structures, wherein:

1-vacuum generator, 2-rotary power unit, 3-vacuum chuck, 4-positioning ring, 5-disc-shaped wafer workpiece, 6-suction hole, 201-mounting base, 202-rotary spindle, 203-spindle motor iii, a 101-transparent locking bolt, a 102-end cap, a 103-grinding spindle, a 104-fixed base, a 105-spindle motor i, a 106-laser generating module, a106 a-laser, a 106B-laser channel, a106 c-mirror, a 2-transparent grinding wheel, M-ultra-precision machine tool, L-laser, B1-locking bolt, B2-spindle end disk, B3-round nut, B4-wheel clamp, B5-ultrasonic grinding wheel, B6-vibration transmission disk, B7-piezoelectric driving module, b9-a base, B10-a spindle motor II, B11-a carrying platform, B13-a grinding wheel vibration direction, B601-a ring groove, B701-an inner hole surface, B702-an outer annular surface, B801-an electric energy transmitting mechanism and B802-an electric energy receiving mechanism.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. In addition, the technical features involved in the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

As shown in fig. 1, an embodiment of the present invention provides a fast-positioning ultra-precision wafer grinding apparatus, which includes a fast positioning device and a grinding device, wherein the fast positioning device is used to realize fast positioning of a wafer, and the grinding device is disposed beside the fast positioning device and is used to grind the positioned wafer. Through the cooperation of the device, the accurate positioning and the ultra-precise and high-quality grinding of the wafer can be realized.

Each device is described in more detail below.

As shown in fig. 2, the wafer fast positioning apparatus of the present invention includes a rotary power unit, a vacuum adsorption unit and a positioning ring 4, wherein the positioning ring 4 is used for installing and positioning a wafer to be processed and is installed on the vacuum adsorption unit, the vacuum adsorption unit is installed on the rotary power unit, and the rotary power unit is used for driving the vacuum adsorption unit, the positioning ring thereon and the wafer on the positioning ring to rotate. Through the cooperation of the parts, the wafer can be quickly and accurately positioned, the probability of the wafer being cracked due to collision with foreign objects can be reduced, and the precision and the efficiency of wafer processing are improved.

Referring to fig. 2-4, the vacuum suction unit is mounted on the rotary power unit and can be driven by the rotary power unit to rotate, the vacuum suction unit specifically includes a vacuum chuck 3 and a vacuum generator 1 connected to the vacuum chuck 3, and the vacuum chuck 3 is provided with a plurality of suction holes 6.

Specifically, the rotary power unit comprises a spindle motor iii 203 and a rotary spindle 202 connected with the spindle motor iii 203, the vacuum generator 1 is mounted on the spindle motor iii 203, and the vacuum chuck 3 is mounted on the rotary spindle 202. Further, vacuum chuck's material is the stainless steel, and it is the ladder cylindrical, and adsorption hole 6 is seted up on the columniform tip of ladder, can realize through the adsorption hole that the negative pressure adsorbs, and vacuum chuck's main aspects can be connected with the high axiality of rotatory main shaft is perfect with along with the rotation of rotation main shaft is fast to effectively communicate through pipeline and vacuum generator, the pipeline can be rotatory for vacuum generator. The big end of the vacuum chuck is also provided with a hole for installing the mass block, the hole is preferably arranged on the side surface of the big end of the vacuum chuck, and the mass blocks with different masses can be installed in the hole as required, so that the subsequent dynamic balance test is facilitated. The adsorption holes are uniformly distributed on the boss at the small end of the vacuum chuck, the adsorption holes uniformly distributed on the boss of the vacuum chuck form small-hole negative pressure, reliable negative pressure adsorption force is provided, the wafer and the positioning ring are firmly adsorbed on the vacuum chuck, the depth of the large-hole is about 5mm less than the height of the boss of the vacuum chuck, the positioning ring is prevented from being axially positioned on the vacuum chuck, and the boss with a certain height of the vacuum chuck can prevent a processing cutter such as a grinding wheel and the like from interfering with the vacuum chuck. The vacuum chuck 3 is provided with a threaded hole, and the vacuum chuck 3 can be installed on the rotating spindle by penetrating the threaded hole through a bolt.

More specifically, the adsorption holes 6 on the vacuum chuck are designed according to the size of a conventional wafer and are suitable for wafers of different specifications, and according to the size of the wafer, the designed adsorption hole distribution meets the condition that the radius of a wafer workpiece is more than 0.5mm larger than the radius of a distribution area of the adsorption holes covered by the wafer workpiece, and the aperture is 2-3mm, so that the edge of the wafer cannot be positioned on the adsorption holes after the wafer is correctly positioned, and the wafer edge is prevented from being damaged in the machining process due to the adsorption force of the adsorption holes.

As shown in fig. 7 and 8, the edge of the wafer is covered on the suction hole of the vacuum chuck, and the radius of the workpiece is larger than the radius of the distribution area of the suction holes covered by the edge of the wafer by more than 0.5mm, i.e. the distance between the edge of the wafer and the nearest suction hole covered by the edge of the wafer is larger than 0.5mm, so the design is such that the inventors of the present invention found in practical tests that the suction holes cannot be freely opened, the wafer is easily damaged during grinding when the edge of the wafer is covered on the suction holes, and the wafer is still easily damaged during grinding when the wafer is covered on the vacuum chuck (i.e. the suction holes are not opened) and the distance between the edge of the wafer and the suction holes is below 0.5mm, so through many improvements and designs, the present invention proposes that the suction holes are distributed in a ring shape, and the radius of the workpiece is larger than the radius of the distribution area of the suction holes covered by the workpiece (i.e. the center of the vacuum chuck is distributed to the wall of the suction holes near the edge of the wafer The distance) is larger than 0.5mm, and at the moment, the damage of the edge of the wafer due to the adsorption force of the adsorption hole in the processing process can be effectively avoided.

Further, the vacuum generator 1 can provide enough vacuum negative pressure, and has three modes of no vacuum, low vacuum and high vacuum, and the adsorption force of the low vacuum adsorption and the high vacuum adsorption can be adjusted according to the requirement. Wherein, the pressure in the low vacuum adsorption is-12 psi to-20 psi, preferably-16 psi, and the pressure in the high vacuum adsorption is-25 psi to-30 psi, preferably-27 psi.

Referring to fig. 5, the positioning ring 4 is sleeved outside the vacuum chuck 3 and covers a part of the suction hole 6, and is specifically assembled on the small end boss of the vacuum chuck, so that the positioning ring 4 is sucked on the vacuum chuck 3 through the action of the vacuum generator 1, wherein the vacuum generator 1 provides negative pressure to form negative pressure suction force at the suction hole 6, and the positioning ring 4 is sucked on the vacuum chuck 3. The inner diameter of the positioning ring 4 is matched with the outer diameter of a wafer to be positioned, the clamping and positioning of the wafer are realized through the positioning ring, and meanwhile, the wafer is adsorbed on the vacuum chuck 3 through negative pressure provided by the vacuum generator, so that the rapid and accurate positioning of the wafer is realized through the matching of the positioning ring, the vacuum generator and the adsorption hole.

Specifically, the positioning ring is made of titanium alloy, has the characteristics of high strength, good mechanical property and the like, is not easy to wear and deform, can be used for a long time, and is stable and reliable. The locating ring adopts a split structure, is obtained by ultraprecision machining a complete cylindrical structure into two parts, belongs to a thin-walled part, is provided with a stepped hole inside a cylinder, the diameter of a large hole of the stepped hole and the outer diameter of a boss at the small end of the vacuum chuck form interference fit, can be closely attached to the boss at the small end of the vacuum chuck, ensures the coaxiality of the large hole and the small end of the vacuum chuck, can be used for placing a circular plate-shaped wafer workpiece, and has the size equal to the outer diameter of the wafer workpiece. The two parts of the positioning ring can be quickly installed on the vacuum chuck, the wafer can be quickly and accurately positioned through the synergistic effect of the two parts, the high coaxiality of the wafer and the vacuum chuck is obtained, compared with an integrated structure, the split structure is simple to manufacture and convenient to replace, and the interchangeability is strong. The locating ring 4 is split type structure promptly, is formed by two ring structure combinations that the structure is the same, and the inner wall of ring structure and the lateral wall interference fit of vacuum chuck tip are provided with along its radial annular boss of extending in the ring structure, and the laminating of the upper surface of annular boss and vacuum chuck tip, and its internal diameter equals with the external diameter of wafer.

The positioning ring is divided into two parts, and the positioning ring is obtained by processing a cylindrical part with a stepped hole into two parts in a mode of not influencing the precision of the cylindrical part, so that the positioning ring can be taken down from the direction vertical to the main shaft after a wafer is adsorbed on the vacuum chuck, the friction between the positioning ring and the wafer can be effectively avoided, and the wafer is prevented from being worn and cracked

In order to facilitate the installation and fixation of the positioning device and the assembly with external components, an installation base 201 is arranged outside the rotary power unit, that is, the rotary power unit is installed in the installation base 201, the vacuum generator 1 and the vacuum chuck 3 are respectively arranged at two ends of the installation base 201, the positioning device of the present invention can be assembled on any equipment, for example, a numerical control machine tool, through the installation base 201, and at this time, the vacuum generator 1 can also be installed on the installation base 201.

Referring to fig. 5 and 6, the circular plate-shaped wafer workpiece 5 is constrained by the positioning ring 4, the circular plate-shaped wafer workpiece 5 is installed in the small hole area of the positioning ring 4, the area of the circular plate-shaped wafer workpiece is larger than the area of the distribution area of the adsorption holes on the covered vacuum chuck boss, namely, the outer circle contour of the circular plate-shaped wafer workpiece falls outside the small hole, the diameter of the wafer is larger than the diameter of the adsorption hole area covered, and the edge of the wafer exceeds the small hole area by more than 0.5mm, so that the edge of the workpiece is attached to the solid surface of the vacuum chuck 3 during processing, and can bear larger processing force. The round plate-shaped wafer workpiece is in close contact with the upper surface of the small end of the vacuum chuck, can form close fit with the small hole of the positioning ring, and can be quickly placed into the small hole of the positioning ring so as to be quickly installed on the vacuum chuck and realize quick and accurate positioning.

The vacuum adsorption unit and the positioning ring are arranged on a rotating main shaft of a common numerical control machine tool, so that the common numerical control machine tool can quickly position the wafer. The positioning device provided by the invention has the advantages that the vacuum adsorption unit is modularly designed, the whole body formed by the vacuum adsorption unit and the positioning ring is directly assembled on the rotating main shaft of the existing numerical control machine tool, the machine tool is not required to be modified and specially designed, the wafer can be quickly and accurately positioned relative to the rotating main shaft of the machine tool, and the high-precision grinding processing of the wafer is realized.

The positioning device is a device for positioning a disc-shaped wafer workpiece on a vacuum chuck by combining the vacuum chuck and a positioning ring, the vacuum chuck is connected with a rotating main shaft and a vacuum generator, the positioning ring is installed and fixed on the vacuum chuck, the vacuum chuck and the positioning ring can be manufactured with high precision by adopting the existing high-precision manufacturing process, wherein the excircle precision of the vacuum chuck and the positioning ring can reach 0.01mm, the cylindricity can reach 0.01mm/100mm, the end surface flatness can reach 0.02mm/200mm, the coaxiality between the vacuum chuck and the positioning ring can reach 0.005mm, the positioning ring with high manufacturing precision can be quickly installed on the vacuum chuck, and the positioning ring, the vacuum chuck and the rotating main shaft can be very high in coaxiality. During positioning, the circular plate-shaped wafer workpiece is placed into the small hole of the positioning ring, and due to the high-precision roundness of the hole in the positioning ring and the high-surface-shape precision of the boss plane of the vacuum chuck, the circular plate-shaped wafer workpiece can be quickly positioned on the vacuum chuck and is adsorbed on the boss of the vacuum chuck through low-pressure negative pressure suction. The invention can realize the quick and accurate positioning of the wafer on the ultra-precise machine tool of the power component, shorten the time of the wafer centering step in the traditional installation process, avoid the damage caused by the wafer installation, simultaneously facilitate the dynamic balance adjustment of the subsequent wafer workpiece, greatly optimize the early preparation link of the wafer processing and improve the processing efficiency of the wafer.

The following explains a specific working process of the positioning device of the present invention, which specifically includes the following steps:

firstly, keeping a vacuum generator 1 in a closed state, installing a positioning ring 4 on a boss of a vacuum chuck 3, wherein the inner diameter of a large hole of the positioning ring 4 is in interference fit with the outer diameter of the boss of the vacuum chuck 3, and tightly abutting the positioning ring 4 on the boss of the vacuum chuck 3, so that the positioning ring can be accurately positioned, and the small hole of the positioning ring is also accurately positioned;

then, the round plate-shaped wafer workpiece 5 is placed into the small hole of the positioning ring, so that the round plate-shaped wafer workpiece 5 is quickly and accurately positioned, at the moment, the vacuum emitter 1 is enabled to work in a low vacuum adsorption state, so that the wafer workpiece is adsorbed on the small end surface of the vacuum chuck 3, and the pressure intensity during low vacuum adsorption is-12 psi to-20 psi, preferably-16 psi;

and finally, taking off the two parts of the positioning ring 4 from the direction vertical to the main shaft, so that the friction collision between the positioning ring 4 and the circular plate-shaped wafer workpiece 5 can be avoided, the possibility of wafer breakage is reduced, meanwhile, the vacuum emitter 1 is enabled to work in a high vacuum adsorption state, the circular plate-shaped wafer workpiece 5 is accurately positioned on the vacuum chuck 3, the high coaxiality required by processing is realized, and the pressure intensity during high vacuum adsorption is-25 psi to-30 psi, preferably-27 psi.

The positioning device is used for positioning the wafer, the positioning precision is high, the wafer workpiece can be always positioned in the middle of the vacuum chuck and keeps high coaxiality with the vacuum chuck, the centering operation of the wafer is not needed, the time is saved, and the subsequent dynamic balance test and grinding processing can be carried out after the wafer is positioned. During dynamic balance testing, the spindle motor drives the rotating spindle to rotate, the vacuum chuck arranged on the rotating spindle and the wafer workpiece adsorbed on the vacuum chuck rotate at high speed along with the spindle, and the wafer workpiece is adsorbed on the vacuum chuck by high vacuum, so that the wafer workpiece cannot fall off during dynamic balance testing, and the time required by the dynamic balance debugging process is greatly shortened based on the high positioning precision of the wafer workpiece.

During dynamic balance test, the accessible ultra-precision machine tool tests from dynamic balance test software of taking, it is prior art, it is not repeated here, if the dynamic balance test result is not up to standard, the quality piece on the accessible adjustment vacuum chuck, until satisfying the requirement, and its positioning accuracy of current positioner is low, not only need carry out the centering operation, low positioning accuracy still can influence the dynamic balance test simultaneously, after a dynamic balance test, when changing next wafer, still need carry out the dynamic balance test to neutralization again because the location is inaccurate, the debugging process is complicated, consuming time and wasting force. After one dynamic balance test, the wafer can be directly positioned on the vacuum chuck and then subjected to subsequent grinding processing without dynamic balance debugging due to high positioning precision of the wafer. During grinding, the rotating main shaft drives the wafer to rotate at high speed, and the grinding device is used for grinding the wafer.

The positioning device can realize the quick and accurate positioning of the wafer workpiece on the vacuum chuck and the machine tool rotating main shaft, is suitable for the quick positioning of the wafer workpiece and the circular plate-shaped workpieces made of other materials, greatly shortens the positioning time of the workpiece, has high positioning precision, does not need to repeatedly carry out dynamic balance debugging on the rotating main shaft in the subsequent processing process, shortens the process time for the subsequent processing, further improves the processing efficiency of the circular plate-shaped workpieces such as wafers and the like, and reduces the possibility of damage of the wafers due to friction and collision by taking the positioning ring down from the direction vertical to the main shaft, thereby taking the processing quality and the time cost into consideration.

The grinding device is a laser in-situ auxiliary grinding device or an ultrasonic auxiliary grinding device. As shown in fig. 9, the laser in-situ auxiliary grinding device of the present invention includes a grinding module and a laser generating module, wherein the grinding module is used for grinding a wafer, and the laser generating module is used for emitting laser and emitting the laser along the radial direction of a grinding wheel. Through the mutual cooperation of the modules, the surface quality of the wafer can be improved in the wafer grinding process, the laser in-situ auxiliary grinding processing of the wafer can be realized, the material removal can be efficiently realized, the grinding force is greatly reduced, and the grinding quality is improved.

Referring to fig. 9-11, the grinding module includes a grinding spindle a103, and a transparent grinding wheel a2 and a spindle motor ia 105 disposed at two ends of the grinding spindle a103, wherein the spindle motor ia 105 is configured to rotate the grinding spindle a103 and the transparent grinding wheel a2 thereon to grind the wafer by using the circumference of the transparent grinding wheel a2, such as ultra-precision grinding, such as scribing, edging, etc. Specifically, the output shaft of the spindle motor ia 105 is connected to the grinding spindle a103 to drive the grinding spindle a103 to rotate. The grinding spindle is the core of the whole wafer grinding device, can rotate at a high speed under the drive of a spindle motor, generates laser emitted along the radial direction of the transparent grinding wheel through a laser generating module, focuses on a grinding area to form laser in-situ auxiliary grinding, and laser beams cannot change along with the rotation of the spindle, so that the laser energy can be efficiently utilized, and the high-quality grinding of workpieces is realized.

Specifically, the spindle motor is a high-performance motor suitable for high-speed rotation, the grinding spindle can be driven to rotate at a high speed, and a through hole is formed in the motor so that laser emitted by the laser module can penetrate through the through hole. Furthermore, the middle part of the grinding module is used for installing a laser generation module, so a through hole is formed in the middle part of the grinding spindle A103, the output shaft of the spindle motor IA 105 is a hollow shaft, and a through hole is formed in the middle part of the transparent grinding wheel A2, so that an assembly channel of the laser generation module is formed.

Furthermore, the binder material of the transparent grinding wheel a2 is transparent resin, and the commonly used resin materials mainly include polymethyl methacrylate (PMMA), Allyl Diglycol Carbonate (ADC), Polycarbonate (PC), and the like, wherein the polymethyl methacrylate resin has good light transmittance, and has the characteristics of good machinability, good glossiness, and the like, and therefore, the binder material of the transparent grinding wheel a2 is preferably polymethyl methacrylate. Meanwhile, in order to improve the strength of the grinding wheel, a small amount of high-strength resin materials such as polyvinyl alcohol fiber resin, epoxy resin and the like are doped in the binder material. The transparent grinding wheel of the invention adopts fibrous polyvinyl alcohol resin, the transmittance of the grinding wheel is not influenced while the strength of the grinding wheel is improved, the mass ratio of transparent matrix resin is 95-98%, and the mass ratio of high-strength resin is 2-5%. The abrasive particles are made of artificial diamonds and have light transmittance, the abrasive particles are mainly distributed on the grinding edge of the outer layer of the grinding wheel, and the number of the diamond meshes can be set to be 1500 meshes, 2000 meshes, 3000 meshes and other types according to actual requirements. Specifically, A1% of methyl ethyl ketone peroxide is added into a transparent grinding wheel to serve as a catalyst, reaction combination of polymethyl methacrylate transparent resin and polyvinyl alcohol resin is carried out, the grinding wheel is shaped in a pouring mode, and then the components in the transparent grinding wheel are fully reacted by adopting a sintering process, so that diamond abrasive particles can be wrapped. The resin bond grinding wheel obtained in the mode has the characteristics of high transmittance, low heat resistance and good self-sharpening performance, and meanwhile, the diamond abrasive particles enhance the cutting performance of the grinding wheel. The transparent grinding wheel is arranged on the grinding main shaft and can rotate at a high speed along with the grinding main shaft, and when a workpiece is machined, laser from the laser generating module can penetrate through the transparent grinding wheel and focus on a grinding area of the grinding wheel to heat a workpiece material, so that laser in-situ auxiliary grinding machining is formed, diamond abrasive particle grinding of the workpiece is promoted, grinding force can be greatly reduced, material removal rate is improved, and grinding quality is improved.

Furthermore, the distribution thickness of the light-transmitting abrasive particles in the circumferential surface of the transparent grinding wheel is 2 mm-3 mm, namely, the light-transmitting abrasive particles are distributed in a circumferential area of 2 mm-3 mm from outside to inside along the radial direction of the transparent grinding wheel, namely, a grinding layer with the thickness of 2 mm-3 mm is distributed outside the circumference of the grinding wheel, and the rest part is not added with abrasive particles and is only resin, so that the grinding processing of the wafer can be realized by utilizing the circumferential surface of the grinding wheel distributed with the light-transmitting abrasive particles, and the whole grinding wheel can be only worn by 2-3 mm.

In order to facilitate the grinding device to be assembled on an external power machine tool, a fixed base A104 is also assembled outside the grinding main shaft A103, the base provides mounting support for the grinding main shaft, the main shaft motor and the laser generation module and can be connected with a power component such as an ultra-precision machine tool so as to install the grinding device on a base platform of the ultra-precision machine tool, the whole laser auxiliary grinding main shaft is further installed on the ultra-precision machine tool, the main shaft motor can be controlled to rotate through the ultra-precision machine tool to drive the whole laser auxiliary grinding main shaft to rotate, and a grinding wheel is used for grinding a wafer. The ultra-precision machine tool can adopt a nano-form series high-precision machine tool, including an Z, X, B, C four-axis system four-axis linkage machine tool, but is not limited to the nano-form ultra-precision machine tool, and other machine tools can be adopted according to actual conditions.

Referring to fig. 11, the laser generating module is installed in the middle of the grinding module, and is used for emitting laser coinciding with the axis of the grinding spindle a103, and making the laser penetrate through the transparent grinding wheel a2 to be emitted along the radial direction of the transparent grinding wheel a2, so that the laser is always focused on the part of the wafer to be ground, and laser in-situ auxiliary grinding processing of the wafer is realized.

Referring to fig. 12, the laser generation module includes a laser a106a, a laser path a106b, and a mirror a106c, wherein the laser a106a is mounted on the spindle motor ia 105, the laser path a106b passes through the spindle motor ia 105 and the grinding spindle a103 and extends into the transparent grinding wheel a2, and a particular laser path a106b is secured to the spindle motor housing and passes through the hollow shaft of the spindle motor and the central through hole of the grinding spindle a103 and then extends into the central through hole of the transparent grinding wheel a 2. The laser path A106b is located at one end of the spindle motor IA 105 and connected with a laser A106a, the laser A106a is installed on a shell of the spindle motor, one end of the laser path A106b extending to the transparent grinding wheel A2 is connected with a reflecting mirror A106c, laser emitted by the laser A106a irradiates on the reflecting mirror A106c through the laser path A106b and is emitted along the radial direction of the transparent grinding wheel A2 after being reflected by the reflecting mirror A106 c.

Specifically, the laser path a106b is a slender light glass tube, which is light in weight, and has small dynamic force generated during high-speed rotation, and small holes are formed in the tube wall, so that laser can be directly emitted conveniently without loss. The reflector A106c is installed at the end of the laser path, and can reflect the laser emitted by the laser and emitted through the laser path by using a high-reflectivity reflector, and the reflected laser passes through a small hole formed in the laser path and acts on the grinding area through the transparent locking bolt and the transparent grinding wheel. The laser action area on the transparent grinding wheel can be changed by adjusting the installation angle of the reflecting mirror, and the laser intensity can be changed by adjusting the intensity of the laser source.

Referring to fig. 11, in order to ensure effective assembly of the transparent grinding wheel a2, the wafer grinding apparatus of the present invention is further provided with a clamping module, which includes a transparent locking bolt a101 and an end cap a102, wherein the transparent locking bolt a101 simultaneously serves as a shaft segment for installing and fastening the transparent grinding wheel a2 and assisting passage of laser, after the laser generating module a106 is installed, the transparent grinding wheel a2, the end cap a102 and the transparent locking bolt a101 are installed, the transparent locking bolt a101 fastens the transparent grinding wheel a2, and simultaneously, the transparent material thereof assists passage of laser. Specifically, transparent locking bolt A101 suit is in the outside that laser access A106b extends to the one end of transparent grinding wheel A2 to link to each other with grinding spindle A103, concrete and grinding spindle A103's through-hole threaded connection, can realize the effective installation of emery wheel on the one hand through threaded connection, on the other hand can adjust the interval between transparent locking bolt A101 and grinding spindle A103, and then the clamp force of adjustment emery wheel, and applicable in the assembly of multiple specification emery wheel, also be convenient for the dismantlement and the change of emery wheel simultaneously. Specifically, the transparent grinding wheel a2 is sleeved outside the transparent locking bolt a101, and the end cap a102 is located between the transparent locking bolt a101 and the transparent grinding wheel a2 and used for pressing the transparent grinding wheel a 2.

Specifically, the transparent locking bolt a101 is used for transmitting laser with low loss, and is combined with an end cover to fasten a transparent grinding wheel, the light transmittance requirement of the transparent locking bolt a101 is high, and the base material of the transparent locking bolt a101 is made of a material similar to the transparent grinding wheel, such as polymethyl methacrylate (PMMA), Allyl Diglycol Carbonate (ADC), Polycarbonate (PC), and the like, wherein the light transmittance of polymethyl methacrylate resin is good, and the transparent locking bolt has the characteristics of good machinability, good glossiness, and the like, so that polymethyl methacrylate is preferably selected, and a small amount of high-strength resin material, such as polyvinyl alcohol fiber resin, epoxy resin, and the like, is preferably fibrous polyvinyl alcohol resin, and since the transparent locking bolt only needs to transmit light and lock the grinding wheel, the strength requirement of the transparent locking bolt is not as high as that of the grinding wheel, and therefore, the content of the base resin is increased, the content of the high-strength resin is reduced, the content (mass percent) of the matrix resin is more than 98 percent, and the content (mass percent) of the high-strength resin is less than 2 percent. The transparency of the transparent locking bolt is improved by improving the content of the matrix resin, the laser loss is reduced, the content of the high-strength resin is properly reduced, and the toughness and the service life of the transparent locking bolt are improved. The laser emitted from the laser light path penetrates through the transparent locking bolt and is emitted along the radial direction of the transparent grinding wheel, and the emitting direction of the laser cannot be changed along with the rotation of the laser auxiliary grinding spindle, so that the in-situ laser auxiliary processing of workpiece materials is formed.

During operation, the spindle motor IA 105 drives the grinding spindle A103, the transparent grinding wheel A2 and the clamping module to rotate together, the laser generating module is fixed, laser emitted by the laser generating module is emitted along the radial direction of the transparent grinding wheel A2 and does not change along with the rotation of the transparent grinding wheel A2, and the laser is always irradiated on one position, so that the laser utilization rate and the grinding quality can be greatly improved.

The spindle motor IA 105 of the invention can be a general common spindle motor, and a laser generating module and other components can be combined and installed on the common spindle motor, so that the common spindle motor can carry out laser auxiliary grinding processing. The grinding module (the spindle motor is removed), the laser generation module and the clamping module are designed in a modularized mode, the whole formed by the grinding module, the laser generation module and the clamping module is directly assembled on the existing spindle motor for wafer grinding, the ordinary grinding spindle motor can be used as the spindle motor for laser auxiliary grinding without modifying and specially designing the ordinary grinding spindle motor.

When a wafer is ground, a grinding wheel is generally required to rotate at a high speed of 20000rpm-30000rpm, and in order to guarantee grinding quality, a grinding device is required to meet the requirements of miniaturization and light weight so as to guarantee grinding balance.

The diameter of the wafer is generally A150mm and 300mm, the thickness is generally 0.7 mm-1 mm, have the characteristic of being large and thin, the grinding process to the wafer is generally cutting and edging, while cutting and edging the grinding process of the wafer, etc., need the emery wheel to grind with the processing way perpendicular to the surface of the wafer, adopt the miniaturized radial laser auxiliary grinding device designed in this invention, can act on the surface of the wafer vertically along the laser of radial emission of the emery wheel, as shown in figure 13, in order to realize the heating of the wafer, and realize the treatment such as scribing, edging of the wafer with the peripheral surface of the emery wheel.

As shown in fig. 14, in use, the grinding device is mounted on the B-axis base of the ultra-precision machine tool M, and the ultra-precision machine tool M controls the rotation of the B-axis to drive the grinding device to rotate integrally, thereby changing the contact manner between the grinding wheel and the wafer. The wafer grinding device for realizing laser in-situ auxiliary wafer grinding processing comprises the following procedures: firstly, determining the position of a processing area where a transparent grinding wheel A2 is in contact with a workpiece, and determining the position needing laser focusing; then, a laser A106a is started, laser passes through a laser path A106b and is reflected by a reflector A106c at the moment, then is focused at a certain point of the outer circumference of the transparent grinding wheel A2, the installation angle of a laser generation module A106 is adjusted to enable the laser to be focused at a target point, a spindle motor IA 105 is started to drive a grinding spindle A103 and the transparent grinding wheel A2 to rotate for grinding, and then laser in-situ auxiliary wafer grinding processing is achieved, a wafer can be fixed in the grinding process, and the wafer can also be driven by a numerical control machine to rotate.

The laser in-situ auxiliary grinding device can realize the fixed focusing of laser on a grinding area, is suitable for the grinding of wafer workpieces and other materials, greatly improves the grinding efficiency, shortens the time required by processing, can reduce the grinding force, improves the quality of processed surfaces, and effectively reduces the surface/subsurface damage of the workpieces. The device can be used for carrying out laser in-situ auxiliary wafer grinding, thereby improving the temperature of a grinding area, reducing the hardness of materials, greatly reducing the grinding force, improving the grinding quality and realizing efficient material removal.

As shown in fig. 15, the ultrasonic vibration assisted grinding apparatus of the present invention includes a fixing unit, a grinding unit, a vibration unit, and a spindle motor iib 10 for driving the three units to rotate together, wherein the fixing unit is mounted on an output shaft of the spindle motor iib 10 for mounting and fixing the grinding unit and the vibration unit, the grinding unit is used for grinding a wafer, and the vibration unit is used for generating radial vibration to the grinding unit when the grinding unit performs a grinding operation, so as to achieve ultra-precise ultrasonic vibration grinding of the wafer. The high-efficiency, high-precision and high-quality grinding processing of the wafer can be realized through the matching of the units.

Referring to fig. 15, the fixing unit includes a spindle end disk B2 and a base B9, wherein the spindle end disk B2 is sleeved outside an output shaft of the spindle motor ii B10 and locked to the output shaft of the spindle motor by a locking bolt B1 to be rotatable with the output shaft, the base B9 is sleeved outside a spindle end disk B2 and connected to a housing of the spindle motor ii B10, the spindle end disk B2 rotates with the output shaft of the spindle motor during rotation, the base B9 is fixed, and the spindle end disk B2 rotates relative to the base B9. The whole fixed unit is in a step shape, wherein the large end is close to the end part of the spindle motor and is abutted against the end part of the spindle motor, and the small end is far away from the end part of the spindle motor and is used for installing the grinding unit.

Referring to fig. 15 and 16, the grinding unit, which is disposed at an end of the fixing unit remote from the spindle motor iib 10, i.e., mounted on a small end of the fixing unit, includes an ultrasonic grinding wheel B5, the ultrasonic grinding wheel B5 being mounted on a vibration transmission disc B6 and clamped by a wheel clamp B4, the vibration transmission disc B6 being mounted on the fixing unit, specifically on a small end of the fixing unit, more specifically on an end of a spindle end disc B2 remote from an end of the spindle motor. The vibration transmission disc B6 and the grinding wheel clamp B4 are used for clamping the grinding wheel clamp B4 together in a clamping mode, and effective assembly of the grinding wheel clamp B4 can be guaranteed.

Specifically, the vibration transmission disc B6 is provided with an annular groove for embedding the ultrasonic grinding wheel B5, one surface of the ultrasonic grinding wheel B5 is in contact with the vibration transmission disc B6, and the other surface is pressed by the grinding wheel clamp B4. Further, the vibration transmission disk B6 is provided with an annular groove on the side facing the spindle motor ii B10 for receiving the piezoelectric driving module B7 in the vibration unit, and the vibration transmission disk B6 can resonate with the piezoelectric driving module B7 to generate high-frequency vibration in the radial direction, specifically vibration of 30kHz to 50kHz, while rotating at a high speed. The vibration transmission disc B6 drives the ultrasonic grinding wheel B5 to perform intermittent radial vibration grinding on the wafer while rotating at high speed along with the main shaft end disc B2 during processing. In order to further ensure the installation reliability of the grinding unit, a round nut B3 is also arranged on the spindle end disc B2 and used for pressing a grinding wheel clamp B4.

Furthermore, the middle of the vibration transmission disc B6 is provided with an annular groove B601 at intervals to reduce the rigidity of the middle part, and the whole structure and the size of the vibration transmission disc B6 are designed according to the target resonant frequency through a continuous particle vibration theory and a finite element simulation design technology, so that the vibration of the piezoelectric drive module B7 is efficiently transmitted to the installation position of the ultrasonic grinding wheel B5, and vibration with large enough amplitude is provided for the ultrasonic grinding wheel B5.

Furthermore, the ultrasonic grinding wheel B5 uses artificial diamond as abrasive grains, the type of the bonding agent is the same as that of a common grinding wheel, resin bonding agent, metal bonding agent, electroforming bonding agent and the like can be selected to meet various processing requirements, the ultrasonic grinding wheel B5 is fixed with the vibration transmission disc B6 by using epoxy resin bonding agent, and when the ultrasonic grinding wheel B5 vibrates along with the vibration transmission disc B6 in the radial direction to grind the wafer intermittently.

Referring to fig. 15 and 17, the vibration unit includes a piezoelectric driving module B7 and a non-contact power transmission module, wherein the non-contact power transmission module is installed in one end of the fixing unit near the spindle motor ii B10 and connected to the piezoelectric driving module B7 through a built-in wire to provide an alternating electric field for the piezoelectric driving module B7, and the specific non-contact power transmission module is installed in the large end of the fixing unit. The piezoelectric driving module B7 is mounted in a groove of the vibration transmission disc B6, and is used for converting an alternating current signal of an alternating electric field into a vibration signal and transmitting the vibration to the vibration transmission disc B6, and the vibration transmission disc B6 resonates with the piezoelectric driving module B7, so that the ultrasonic grinding wheel B5 thereon generates high-frequency vibration in the radial direction while rotating.

Specifically, the piezoelectric driving module B7 is a circular ring-shaped piezoelectric ceramic, and is embedded in a groove of the vibration transmission disc B6 by using epoxy resin glue. The piezoelectric driving module B7 is made of PZT-8 and works at d₃₃Piezoelectric mode, capable of providing a large output power, with density and modulus of elasticity close to the property parameters of vibration transmission disc B6. Electrodes, specifically silver electrodes, are laid on the inner hole surface B701 and the outer circular ring surface B702 of the piezoelectric driving module B7, and polarization processing is performed in the radial direction of the piezoelectric driving module B7, that is, the inner hole surface and the outer circular ring surface of the piezoelectric driving module B7 are charged with positive and negative charges. Under the condition that the non-contact power transmission module is continuously powered, namely, by receiving a high-frequency electric field from the non-contact power transmission module, a radial electric field is generated between the electrodes on the inner hole surface and the outer ring surface of the piezoelectric driving module B7 to realize radial resonance, and the frequency of an electric signal of the power receiving mechanism 02 can be changed while the power receiving mechanism rotates at a high speed, so that the electric field periodically changes according to a target frequency, and the piezoelectric driving module is excited to generate radial high-frequency vibration.

As shown in fig. 15, the contactless power transmission module includes a power transmitting mechanism B801 and a power receiving mechanism B802, the power transmitting mechanism B801 and the power receiving mechanism B802 are respectively embedded in a base B9 and a main shaft end plate B2, as shown in fig. 15, the power transmitting mechanism B801 is embedded in a base B9, and the power receiving mechanism B802 is embedded in a main shaft end plate B2 to provide an alternating electric field for the piezoelectric driving module B7. The electric energy transmitting mechanism B801 and the electric energy receiving mechanism B802 are opposite to each other and both consist of coil windings and fixed magnetic cores, the coil windings in the electric energy receiving mechanism B802 are connected with the piezoelectric driving module B7 through built-in leads, an ultrasonic frequency oscillation electric signal is generated by an ultrasonic power supply connected to the electric energy transmitting mechanism B801, the fixed magnetic cores on the electric energy transmitting mechanism B801 generate a high-frequency alternating magnetic field, and then the coil windings on the electric energy receiving mechanism B802 generate the same-frequency induced electromotive force acting on the piezoelectric driving module B7. The piezoelectric driving module is powered by a non-contact electric energy transmission module, a transmitting mechanism of the non-contact electric energy transmission module is fixed on a shell of a spindle motor, a receiving mechanism is fixed on the right side of a spindle end disc and is connected with the piezoelectric driving module through a built-in lead, when the device works, the transmitting mechanism of the non-contact electric energy transmission module is still, and the receiving mechanism rotates along with the spindle end disc.

Specifically, the spindle motor iib 10 is a general ordinary spindle motor, and only the vibration transmission disk B6, the piezoelectric drive module B7, the ultrasonic grinding wheel B5, the non-contact power transmission module and the like need to be installed on the rotating spindle in a combined manner, so that the ordinary spindle motor can generate high-frequency radial ultrasonic vibration. An output shaft of the spindle motor IIB 10 is connected with a spindle end disc through a locking bolt, and the rotation of the output shaft of the spindle motor drives the grinding unit, the piezoelectric driving module and the non-contact type electric energy receiving module to rotate, so that the ultrasonic grinding wheel is driven to rotate at a high speed, and the wafer fixed on the carrying platform is subjected to intermittent vibration grinding. The main shaft motor body does not transmit vibration, other units of the ultrasonic vibration device are biased to the modularized design, the main shaft motor for common wafer grinding, such as an air main shaft motor, can be modified on site, the whole body formed by the fixing unit, the grinding unit and the vibration unit is directly assembled on the main shaft motor for the conventional wafer grinding, the modification and special design of the main shaft motor for common grinding are not needed, and the main shaft motor for common grinding can be used as the main shaft motor for ultrasonic vibration grinding.

When a wafer is ground, a grinding wheel is generally required to rotate at a high speed of 20000rpm-30000rpm, in order to guarantee grinding quality, a grinding device is required to meet the requirements of miniaturization and light weight so as to guarantee grinding balance.

The diameter of the wafer is generally 150mm and 300mm, the thickness is generally 0.7 mm-1 mm, the wafer grinding process is generally cutting and edging, as shown in fig. 20, when the wafer cutting and edging and other grinding processes are carried out, the grinding wheel is required to grind in a processing mode vertical to the surface of the wafer, and by adopting the miniaturized radial ultrasonic vibration grinding device designed by the invention, the radial vibration of the grinding wheel can be vertically acted on the surface of the wafer, so that the wafer cutting, edging and other treatments are realized.

As shown in fig. 18 and 19, in use, the ultrasonic vibration assisted grinding device is arranged beside the quick positioning device, and then ultrasonic vibration assisted grinding is carried out, which specifically comprises the following steps:

firstly, an ultrasonic grinding wheel B5 is arranged on a main shaft end disc B2 through a round nut B3 and a grinding wheel clamp B4, and a piezoelectric drive module B7 is embedded in a groove of a vibration transmission disc B6 through epoxy resin glue;

then, an electric energy receiving mechanism B802 of the non-contact electric energy transmission module is arranged on a main shaft end disc B2, and an electric energy emitting mechanism B801 is arranged on a base B9;

then, a spindle end disc B2 with a round nut B3, a grinding wheel clamp B4, an ultrasonic grinding wheel B5, a vibration transmission disc B6, a piezoelectric driving module B7 and a non-contact power transmission module is fixed on an output shaft of a spindle motor II B10 through a locking bolt B1;

finally, the position of the ultrasonic grinding wheel B5 relative to the wafer is adjusted, power is supplied to an electric energy emitting mechanism B801 of the non-contact type electric energy transmission module, the spindle motor II B10 is started through the control device to drive other components to rotate at a high speed, then the wafer fixed on the carrying platform B11 can be subjected to vibration grinding, and the vibration direction is perpendicular to the surface of the wafer, so that high-quality cutting and edge grinding of the wafer are achieved.

The grinding device provided by the invention applies ultrasonic vibration to the grinding wheel in common grinding processing to change the contact state and action mechanism between the grinding wheel and the wafer, increase the plastic removal proportion and material removal rate of materials, reduce the grinding force and the abrasion loss of the grinding wheel, improve the grinding quality and improve the grinding efficiency. The ultrasonic vibration auxiliary grinding device can be modified on the common grinding wheel and the spindle motor in situ, saves the processing cost, can realize high-efficiency, high-precision and high-quality wafer grinding, can effectively reduce the grinding force in the wafer grinding process, improves the cooling effect of abrasive particles on the grinding wheel, further improves the wafer processing quality, and prolongs the service life of the grinding wheel.

The operation process of the ultra-precise grinding equipment of the invention is explained below, when in use, the grinding equipment of the invention can be assembled on an ultra-precise machine tool, namely, a grinding device and a positioning device are installed on the ultra-precise machine tool, for example, the grinding device is installed on the B-axis table surface of the ultra-precise machine tool, the positioning device is arranged beside the grinding device, the installation position of the grinding device on the B axis can be adjusted based on a positioning hole on the B-axis table surface of the ultra-precise machine tool, the processing included angle between the grinding device and a wafer workpiece can be adjusted by adjusting the angle of the B axis, and a spindle motor in the grinding device can be controlled by the ultra-precise machine tool or directly replaced by the spindle motor of the ultra-precise machine tool, so that the precise control can be realized based on the rotating speed of the wafer workpiece of the ultra-precise machine tool, the rotating speed of a grinding spindle and the matching between the wafer and the grinding axis, and the positioning device is utilized to quickly position the wafer workpiece after the assembly, and after the wafer is positioned, grinding by using a grinding device. When the ultrasonic vibration auxiliary grinding device is adopted for grinding, an excitation signal is transmitted to the piezoelectric driving unit through an excitation electric signal of the ultrasonic vibration auxiliary grinding device, a controllable alternating electric field is formed, annular piezoelectric ceramics embedded in the ultrasonic vibration grinding wheel are excited to generate high-frequency vibration, the ultrasonic vibration grinding wheel is driven to resonate together to generate high-frequency radial vibration, and the ultrasonic vibration auxiliary grinding wheel rotates at a high speed under the drive of the spindle motor, and meanwhile, the high-frequency intermittent vibration grinding processing of a wafer workpiece is realized. When in-situ laser-assisted grinding is adopted, the position of a processing area where a transparent grinding wheel is in contact with a workpiece is determined, the position needing laser focusing is determined, then a laser is started, the laser passes through a laser passage and is reflected by a reflector, then the laser is focused at a certain point of the outer circumference of the transparent grinding wheel, the installation angle of a laser generating module is adjusted to enable the laser to be focused at a target point, a spindle motor is started to drive a grinding spindle and the transparent grinding wheel to rotate for grinding, and then laser in-situ-assisted wafer grinding processing is realized.

It will be understood by those skilled in the art that the foregoing is only a preferred embodiment of the present invention, and is not intended to limit the invention, and that any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the scope of the present invention.

Claims

1. The ultra-precise wafer grinding equipment capable of achieving rapid positioning is characterized by comprising a rapid positioning device and a grinding device, wherein the rapid positioning device is used for achieving rapid positioning of a wafer and comprises a rotary power unit, a vacuum adsorption unit and a positioning ring (4), the vacuum adsorption unit is installed on the rotary power unit and can be driven to rotate by the rotary power unit and comprises a vacuum chuck (3) and a vacuum generator (1) connected with the vacuum chuck (3), and a plurality of adsorption holes (6) which are uniformly distributed are formed in the vacuum chuck (3); the positioning ring (4) is sleeved outside the vacuum chuck (3) and covers a part of the adsorption hole (6), so that the positioning ring (4) is adsorbed on the vacuum chuck (3) under the action of the vacuum generator (1), and the inner diameter of the positioning ring (4) is adapted to the outer diameter of a wafer to be positioned; the grinding device is arranged beside the quick positioning device and used for grinding the positioned wafer.

2. The ultra-precise wafer grinding equipment capable of being rapidly positioned according to claim 1, wherein the grinding device is a laser in-situ auxiliary grinding device which comprises a grinding module and a laser generation module, the grinding module is used for grinding the wafer and comprises a grinding spindle (A103), and a transparent grinding wheel (A2) and a spindle motor I (A105) which are arranged at two ends of the grinding spindle (A103), and the spindle motor I (A105) is used for driving the grinding spindle (A103) and the transparent grinding wheel (A2) thereon to rotate so as to grind the wafer by using the circumference of the transparent grinding wheel (A2); the laser generating module is arranged in the middle of the grinding module and used for emitting laser which is coincident with the axis of the grinding spindle (A103), enabling the laser to penetrate through the transparent grinding wheel (A2) to be emitted along the radial direction of the transparent grinding wheel, and then focusing on the part to be ground of the wafer, so that laser in-situ auxiliary grinding processing of the wafer is achieved.

3. The ultra-precision wafer grinding apparatus capable of being positioned quickly as claimed in claim 2, wherein the laser generation module comprises a laser (a 106 a), a laser path (a 106 b) and a mirror (a 106 c), the laser (a 106 a) is mounted on a spindle motor i (a 105), the laser path (a 106 b) passes through the spindle motor i (a 105) and the grinding spindle (a 103) and extends into a transparent grinding wheel (a 2), one end of the spindle motor i (a 105) is connected with the laser (a 106 a), one end of the transparent grinding wheel (a 2) is connected with the mirror (a 106 c), and the laser emitted by the laser (a 106 a) passes through the laser path (a 106 b) to irradiate the mirror (a 106 c) and is reflected by the mirror (a 106 c) and then is emitted along a radial direction of the transparent grinding wheel (a 2).

4. The ultra-precision wafer grinding device capable of being rapidly positioned according to claim 3, wherein the laser passage (A106 b) is an elongated light glass tube, and a hole is formed in the wall of the glass tube at a position corresponding to the laser emitting position.

5. The ultra-precise wafer grinding device capable of being positioned quickly as claimed in claim 3, wherein the laser in-situ auxiliary grinding device further comprises a clamping module, the clamping module comprises a transparent locking bolt (A101) and an end cap (A102), the transparent locking bolt (A101) is sleeved on the outer portion of one end of the laser passage (A106 b) extending to the transparent grinding wheel (A2) and is connected with the grinding spindle (A103), the transparent grinding wheel (A2) is sleeved on the outer portion of the transparent locking bolt (A101), and the end cap (A102) is positioned between the transparent locking bolt (A101) and the transparent grinding wheel (A2) and is used for pressing the transparent grinding wheel (A2).

6. The ultra-precise wafer grinding device capable of being positioned quickly according to claim 5, wherein the transparent locking bolt (A101) is made of transparent matrix resin doped with high-strength resin, wherein the mass percentage of the transparent matrix resin is more than 98%, and the mass percentage of the high-strength resin is less than 2%.

7. The ultra-precise wafer grinding device capable of being rapidly positioned according to claim 2, wherein the transparent grinding wheel (A2) is made of transparent matrix resin doped with high-strength resin, and the mass ratio of the transparent matrix resin to the high-strength resin is (95% -98%): (5% -2%), and light-transmitting abrasive particles are uniformly distributed in the circumferential surface of the transparent grinding wheel (A2).

8. The rapidly positionable ultra-precise wafer grinding apparatus according to claim 6 or 7, wherein the transparent matrix resin is one or more of polymethyl methacrylate, allyl diglycol carbonate, and polycarbonate, and the high strength resin is one or more of polyvinyl alcohol fiber resin and epoxy resin.

9. The ultra-precise wafer grinding equipment capable of being rapidly positioned according to claim 7, wherein the distribution thickness of the light-transmitting abrasive particles in the circumferential surface of the transparent grinding wheel (A2) is 2 mm-3 mm, and the light-transmitting abrasive particles are made of artificial diamond.

10. The ultra-precise wafer grinding apparatus capable of being rapidly positioned according to claim 1, wherein the grinding device is an ultrasonic vibration assisted grinding device comprising a fixing unit, a grinding unit, a vibration unit and a spindle motor II (B10) for driving the three units to rotate together, the fixing unit is mounted on an output shaft of the spindle motor II (B10) for mounting and fixing the grinding unit and the vibration unit; the grinding unit is arranged at one end of the fixing unit far away from the spindle motor II (B10) and comprises an ultrasonic grinding wheel (B5), the ultrasonic grinding wheel (B5) is mounted on a vibration transmission disc (B6) and clamped by a wheel clamp (B4), and the vibration transmission disc (B6) is mounted on the fixing unit; the vibration unit comprises a piezoelectric driving module (B7) and a non-contact type power transmission module, wherein the non-contact type power transmission module is arranged in one end of the fixing unit close to the spindle motor II (B10) and is connected with the piezoelectric driving module (B7) so as to provide an alternating electric field for the piezoelectric driving module (B7); the piezoelectric driving module (B7) is arranged in the vibration transmission disc (B6) and used for converting alternating current signals into vibration signals and transmitting the vibration to the vibration transmission disc (B6), and the vibration transmission disc (B6) resonates with the piezoelectric driving module (B7), so that the ultrasonic grinding wheel (B5) generates high-frequency vibration along the radial direction while rotating.

11. The ultra-precision wafer grinding apparatus capable of being positioned quickly as claimed in claim 10, wherein the fixing unit comprises a spindle end disk (B2) and a base (B9), the spindle end disk (B2) is sleeved on the output shaft of the spindle motor ii (B10) and locked by a locking bolt (B1), and the base (B9) is sleeved on the outer portion of the spindle end disk (B2) and fixed on the spindle motor ii (B10).

12. The ultra-precise wafer grinding apparatus capable of being positioned quickly as claimed in claim 11, wherein the non-contact power transmission module comprises a power transmitting mechanism (B801) and a power receiving mechanism (B802), and the power transmitting mechanism (B801) and the power receiving mechanism (B802) are respectively embedded in the base (B9) and the spindle end disk (B2).

13. The ultra-precision wafer grinding device capable of being positioned quickly as claimed in claim 12, wherein the power transmitting mechanism (B801) and the power receiving mechanism (B802) are both composed of coil windings and fixed magnetic cores, and an ultrasonic power source connected to the power transmitting mechanism (B801) is used to generate an ultrasonic frequency oscillating electrical signal, so that the fixed magnetic core on the power transmitting mechanism (B801) generates a high-frequency alternating magnetic field, and further the coil windings on the power receiving mechanism (B802) generates a same-frequency induced electromotive force acting on the piezoelectric driving module (B7).

14. The ultra-precision wafer grinding device capable of being rapidly positioned according to claim 11, wherein a round nut (B3) is further mounted on the spindle end disc (B2) for pressing the grinding wheel clamp (B4), and the vibration transmission disc (B6) is provided with spaced ring grooves (B601).

15. The ultra-precise wafer grinding apparatus capable of being rapidly positioned according to claim 10, wherein the piezoelectric driving module (B7) is a ring-shaped piezoelectric ceramic, which is polarized in the radial direction and has electrodes laid on the inner hole surface (B701) and the outer ring surface (B702), and under the continuous power supply of the non-contact power transmission module, a radial electric field is generated between the electrodes on the inner hole surface and the outer ring surface of the piezoelectric driving module (B7), and high-frequency vibration in the radial direction is generated through the periodic variation of the electric field frequency.

16. The ultra-precision wafer grinding apparatus capable of being rapidly positioned according to claim 10, wherein the ultrasonic grinding wheel (B5) is a diamond abrasive wheel, and the spindle motor ii (B10) is an air spindle motor.

17. The ultra-precise wafer grinding device capable of being rapidly positioned according to claim 1, wherein the vacuum chuck (3) is in a stepped cylindrical shape, the large end of the vacuum chuck is connected with the rotary power unit and is communicated with the vacuum generator (1) through a pipeline, the adsorption holes (6) are formed in the small end of the vacuum chuck (3), the adsorption holes (6) are communicated with the pipeline, and a hole for installing a mass block is further formed in the large end of the vacuum chuck (3).

18. The ultra-precise wafer grinding device capable of achieving rapid positioning according to claim 1, wherein the positioning ring (4) is a split structure and is formed by combining two ring structures with the same structure, the inner wall of the ring structure is in interference fit with the side wall of the small end of the vacuum chuck, the ring structure is further provided with an annular boss extending along the radial direction of the ring structure, the annular boss is attached to the upper surface of the small end of the vacuum chuck, and the inner diameter of the annular boss is equal to the outer diameter of the wafer.

19. The ultra-precise wafer grinding device capable of being rapidly positioned according to claim 1, wherein the adsorption holes (6) are annularly distributed with the center of the vacuum chuck (3) as a center, and are designed to satisfy the following conditions: the radius of the wafer is larger than that of the adsorption hole area covered by the wafer by more than 0.5mm, and the diameter of the adsorption hole (6) is designed to be 2 mm-3 mm.

20. The ultra-precise wafer grinding apparatus capable of rapid positioning according to claim 1, wherein the vacuum chuck (3) is made of stainless steel and the positioning ring (4) is made of titanium alloy.

21. The apparatus of any of claims 1-7 or 9-20, wherein the rotational power unit comprises a spindle motor iii (203) and a rotating spindle (202) connected thereto, the vacuum generator (1) is mounted on the spindle motor iii (203), and the vacuum chuck (3) is mounted on the rotating spindle (202).