CN118664477A - Dual auxiliary wafer cutting equipment combining laser and ultrasound - Google Patents

Abstract

The invention discloses a dual auxiliary wafer cutting device combining laser and ultrasonic, which belongs to the technical field of precision machining, and comprises: z, Y axis moving mechanism, Y axis moving mechanism, main shaft base, main shaft, cutter, laser auxiliary module and ultrasonic vibration auxiliary module; the piezoelectric element is arranged between the cutter and the main shaft; the laser emitted by the laser head is focused on the processing position of the cutter, so that the processing part of the workpiece is in a brittle plastic critical state; the piezoelectric element vibrates, and the cutter instantaneously vibrates radially, so that the contact state between the cutter and the workpiece is changed, and therefore abrasive particles and the workpiece frequently collide at a high speed, the grinding effect in the cutting process is enhanced, a micro gap is formed between the cutter and the workpiece under the vibration effect, the flow of cooling liquid is facilitated, heat generated in the processing process is effectively carried away, and the abrasive particles are prevented from being overheated and passivated.

Description

A wafer cutting device combining laser and ultrasonic dual assistance

Technical Field

The invention belongs to the field of precision machining, and in particular relates to a wafer cutting device combining laser and ultrasonic dual-assisted wafer cutting.

Background Art

Monocrystalline silicon is a hard and brittle material. Due to its excellent properties such as high temperature resistance, wear resistance, low density and high strength, it has extremely broad application prospects in aerospace, biomedicine, precision manufacturing and other fields. Key components made of these materials have a long service life and application characteristics compared to traditional materials due to their excellent mechanical properties. However, at the same time, monocrystalline silicon must undergo precision machining to achieve high dimensional shape accuracy and surface quality requirements, so as to be made into chips.

Traditional wafer cutting technology mainly relies on ultra-thin diamond wheel cutting, which has low cutting efficiency, serious damage, and is prone to cause sub-surface damage problems such as edge collapse, corner collapse, and layered peeling on the wafer surface.

In order to solve these problems, laser-assisted wafer cutting technology has gradually attracted attention in recent years, but laser cutting has problems such as slow processing speed and unstable cutting quality; ultrasonic vibration-assisted processing technology is favored because it can achieve high-precision processing on a microscopic scale, but when used alone for wafer cutting, it has problems such as slow processing speed and high cutting surface roughness; therefore, considering combining laser and ultrasonic dual-assisted wafer cutting technology is one of the effective means to solve wafer cutting problems.

Summary of the invention

In order to solve the above problems, the present invention provides a wafer cutting device combining laser and ultrasonic dual assistance.

A wafer cutting device combining laser and ultrasonic dual auxiliary, comprising: a laser auxiliary module, an ultrasonic vibration auxiliary module, a detection module, a spindle base, a bearing table, a tool, a spindle, a Z-axis moving mechanism, an X-axis moving mechanism, a Y-axis moving mechanism, and a gantry;

Furthermore, the ultrasonic vibration auxiliary module includes an ultrasonic power supply, a piezoelectric element, a power supply unit, and a conductive slip ring; wherein the piezoelectric element is a tiny vibration unit based on the principle of piezoelectric effect, and there are four of them, which are evenly distributed around the main shaft; the power supply unit is a non-contact power transmission unit based on the principle of loosely coupled electromagnetic induction, and there are four of them, which are symmetrically distributed around the main shaft; the power supply unit is clamped by chuck No. 1 and chuck No. 2, and the connection is a tight connection, and the fit is an interference fit;

Optionally, the tool is a customized electrocast hub-type ultra-thin diamond grinding wheel, which can be used in an ultrasonic vibration-assisted cutting unit, and the tool and the piezoelectric element are transitionally matched;

Furthermore, the tool is fixed on the spindle, and is in transitional fit with the piezoelectric element and the spindle; the spindle is placed on a spindle base at the lower edge of the Z-axis moving mechanism; the gantry is used to carry components such as the X-axis moving mechanism, the Z-axis moving mechanism and the spindle base, and the Z-axis moving mechanism is fixed to the gantry by bolts;

Furthermore, at least two of the piezoelectric elements are installed between the tool and the spindle; at least two of the piezoelectric elements are evenly distributed around the spindle;

Optionally, the piezoelectric element is a piezoelectric ceramic, and vibration is achieved by using the piezoelectric effect and voltage effect principle of the piezoelectric ceramic;

Furthermore, the ultrasonic power supply is used to generate a high-frequency sinusoidal alternating current signal, the spindle motor is used to realize the rotation of the tool, and the high-frequency sinusoidal alternating current signal generated by the ultrasonic power supply is transmitted to the piezoelectric element through the ultrasonic transmission device, so that the tool generates ultrasonic vibration, thereby realizing ultrasonic-assisted cutting of the workpiece;

Furthermore, the Z-axis moving mechanism, the X-axis moving mechanism and the Y-axis moving mechanism have the same structure, and are all slides, composed of guide rails, lead screws, nuts, sliders, motors, and fixed plates. The Z-axis moving mechanism and the X-axis moving mechanism are connected by bolts, and the lower edge of the Z axis is connected to the spindle base, the laser auxiliary module and the tool. The X-axis moving mechanism and the Z-axis moving mechanism are mainly responsible for the feeding movement in the X and Z directions;

Furthermore, the carrier is a turntable, the workpiece is fixed by a fixing fixture and rotates clockwise at a constant speed along with the carrier; the fixed plate of the Y-axis moving mechanism is used as a supporting platform for the workpiece and the detection module, and is responsible for feeding in the Y direction;

Furthermore, in step 2, the laser auxiliary module includes a horizontal fixing rod, a first connecting rod, a laser, and a laser head, and the laser auxiliary module is fixed on the spindle base through the horizontal fixing rod; during processing, the laser is always focused on the processing position along the processing trajectory for laser-assisted softening, and the laser auxiliary module moves synchronously with the spindle base;

Optionally, the laser is a pulsed laser, and the output is femtosecond or picosecond laser.

Furthermore, the auxiliary cutting laser is a laser with a wavelength of 1064nm and a power adjustable within the range of 50 to 150W; the spindle speed is 12000rpm and the power is 2.0 to 2.2KW.

Furthermore, the processing parameters may be selected according to the characteristics of the workpiece material, and the processing parameters include the power of the laser used for auxiliary cutting, the rotation speed of the grinding wheel, the amplitude of the ultrasonic vibration, and the size of the laser spot.

Furthermore, the detection module includes a camera, a temperature sensor, a connecting piece, a Y-axis slide rail and a second connecting piece. The Y-axis slide rail in the detection module is used to adjust the position of the camera relative to the workpiece, and the camera angle of the detection module can be adjusted through the connecting piece.

Another object of the present invention is to provide a processing method combining laser and ultrasonic dual-assisted wafer cutting, the specific steps are as follows:

1) Paste a film on the back of the workpiece; the film is a UV film or a blue film;

2) Fix the workpiece with a fixture;

3) Input the motion trajectory parameters of the tool and the carrier into the industrial computer;

4) Adjust the relative position between the workpiece and the laser, and focus the laser beam on the processing position surface of the workpiece and the tool; the workpiece is processed to the critical state of brittle plasticity;

5) Piezoelectric element vibration, tool radial vibration; piezoelectric elements are evenly distributed around the spindle, the vibrations cancel each other out and do not affect the spindle rotation;

6) The tool cuts the workpiece.

Optionally, the workpiece is a large-sized ultra-thin single-crystal silicon wafer, which is a hard and brittle material.

Furthermore, during the above processing, deionized water needs to be sprayed continuously from all directions; when the temperature of the processing area detected by the temperature sensor of the detection module exceeds the critical plastic brittle temperature of the workpiece, the industrial computer issues a command to continuously spray deionized water on the processing area to avoid thermal damage.

The present invention provides a laser-assisted processing technology. In laser preheating-assisted processing, the laser beam irradiation point is made several millimeters lower than the tool center, thereby avoiding the problem of excessive heat-affected zone in existing laser preheating-assisted processing methods. The tool center needs to be flush with the center of the workpiece end face, so that the laser heating point is always lower than the workpiece center, thereby effectively achieving the heating and softening effect when processing the center area of the workpiece; during the processing process, the laser heating action area is as close to the cutting area as possible, so that the heat-affected zone is minimized.

Furthermore, the laser can be focused in front of the tool, solving the problem of single feed direction processing, achieving high-quality processing while shortening the processing time of complex paths; at the same time, this processing method overcomes the structural interference limitations of the tool, allowing the laser emission point to be close to the tool edge and flexibly adjusted, achieving laser online preheating auxiliary heating effects controlled by different parameters.

The present invention also provides an ultrasonic vibration-assisted processing technology, which is applied to the cutting tool. Through the instantaneous radial vibration of the cutting tool, the contact state between the cutting tool and the workpiece changes, so that the abrasive particles and the workpiece collide frequently at high speed, intensifying the grinding effect during the cutting process, thereby introducing an innovative processing mechanism during the cutting process; the application of this ultrasonic vibration-assisted processing technology can effectively reduce the energy consumption of the cutting process, further improve the processing efficiency, and also reduce the heat generated during the cutting process, which is beneficial to prevent deformation and damage to the workpiece surface.

Furthermore, ultrasonic vibration-assisted processing technology also improves the cooling effect of abrasive particles; under the action of vibration, a small gap is formed between the tool and the workpiece, which is conducive to the flow of coolant, effectively taking away the heat generated during the processing, preventing the abrasive particles from overheating and passivation, thereby extending the service life of the tool.

Among them, this gap also helps to prevent the occurrence of phenomena such as pore clogging and abrasive passivation, further improving the processing quality and stability.

The present invention uses dual composite assisted diamond grinding wheel to cut single crystal silicon using laser-assisted and ultrasonic vibration-assisted processing technologies, innovatively focusing the laser precisely on the workpiece surface, and simultaneously realizing laser assistance and ultrasonic vibration assistance along the processing trajectory, effectively reducing sub-surface damage and further improving processing efficiency and processing surface quality.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is an overall three-dimensional schematic diagram of a wafer cutting device combining laser and ultrasonic dual-assisted wafer cutting according to an embodiment of the present invention.

FIG2 is a front view of the overall structure of a wafer cutting device combining laser and ultrasonic dual-assisted wafer cutting according to an embodiment of the present invention.

FIG3 is a three-dimensional schematic diagram of a Y-axis movable slide provided in an embodiment of the present invention.

FIG. 4 is a top view of the Y-axis movable slide provided in an embodiment of the present invention.

FIG. 5 is a schematic diagram of a laser auxiliary module provided in an embodiment of the present invention.

FIG. 6 is a schematic diagram of a detection module provided in an embodiment of the present invention.

FIG. 7 is a schematic diagram of an ultrasonic vibration auxiliary module provided in an embodiment of the present invention.

FIG. 8 is a schematic diagram of a cutting process provided by an embodiment of the present invention.

Among them, 1. Laser auxiliary module; 1-1. Horizontal fixed rod; 1-2. First connecting rod; 1-3. Laser; 1-4. Laser head; 2. Ultrasonic vibration auxiliary module; 2-1. Piezoelectric element; 2-2. Power supply unit; 2-3. Conductive slip ring; 3. Detection module; 3-1. Camera; 3-2. Temperature sensor; 3-3. Connector; 3-4. Y-axis slide rail; 3-5. Second connecting rod; 4. Spindle base; 4-1. No. 1 chuck; 4-2. No. 2 chuck; 5. Carrying platform; 5-1. Fixing fixture; 5-2. Workpiece; 6. Tool; 7-1. Z-axis moving mechanism; 7-2. X-axis moving mechanism; 8. Gantry; 9. Y-axis moving mechanism; 9-1. Fixed plate; 9-2. Motor; 9-3. Guide rail; 9-4. Slider; 9-5. Lead screw; 10. Spindle.

DETAILED DESCRIPTION

Example 1

An embodiment of the present invention provides a wafer cutting device that combines laser and ultrasonic dual-assisted wafer cutting, including a laser-assisted module 1, an ultrasonic vibration-assisted module 2, a detection module 3, a spindle base 4, a carrier table 5, a tool 6, a Z-axis moving mechanism 7-1, an X-axis moving mechanism 7-2, a gantry 8, a Y-axis moving mechanism 9, and a spindle 10.

In one embodiment of the present invention, the tool 6 is fixed to the spindle 10 through a hard tool flange, and the spindle 10 is placed on the spindle base 4 at the lower edge of the Z-axis moving mechanism 7-1, and two through holes for the laser auxiliary module 1 and the ultrasonic vibration auxiliary module 2 are arranged between the spindle 10 and the spindle base 4, and power cables are arranged in the passages; the gantry 8 is used to carry components such as the Z-axis moving mechanism 7-1, the X-axis moving mechanism 7-2 and the spindle base 4, and the Z-axis moving mechanism 7-1 is fixed to the gantry 8 by bolts.

The above-mentioned tool 6 is a customized electrocast hub-type ultra-thin diamond grinding wheel, which can be used in an ultrasonic vibration-assisted cutting unit. The tool 6 and the piezoelectric element 2-1 are transitionally matched.

The spindle 10 is an air static pressure spindle with a rotation speed of 3500-12000 rpm and a power of 2.0-2.2 kW.

In one embodiment of the present invention, the Z-axis moving mechanism 7-1, the X-axis moving mechanism 7-2 and the Y-axis moving mechanism 9 have the same structure and are all slides; taking the Y-axis moving mechanism 9 as an example, it is composed of a fixed plate 9-1, a motor 9-2, a guide rail 9-3, a slider 9-4, and a lead screw 9-5; the Z-axis moving mechanism 7-1 and the X-axis moving mechanism 7-2 are connected by bolts, and the lower edge of the Z axis is connected to the spindle base 4, the spindle 10, the laser module 1 and the tool 6, and the X-axis moving mechanism 7-2 and the Z-axis moving mechanism 7-1 are responsible for controlling the feed movement of the spindle 10 in the X and Z directions respectively; the fixed plate 9-1 of the Y-axis moving mechanism 9 serves as a support platform for the workpiece 5-2 and the detection module 3, and undertakes the feed movement in the Y direction, the fixed plate 9-1 and the second connecting rod 3-5 of the detection module 3 are fixed by screws, and the bearing platform 5 is fixed to the fixed plate 9-1 by screws.

The above-mentioned supporting platform 5 is a turntable, and the workpiece 5 - 2 is fixed by a fixing fixture 5 - 1 and rotates clockwise at a constant speed along with the supporting platform 5 .

The above-mentioned workpiece 5-2 is a large-sized ultra-thin single-crystal silicon wafer, which is a hard and brittle material.

Optionally, the X-axis moving mechanism 7 - 2 may be equipped with a grating ruler to perform closed-loop control of the motion trajectory and stroke of the tool 6 .

In one embodiment of the present invention, the ultrasonic vibration auxiliary module 2 includes an ultrasonic power supply, a piezoelectric element 2-1, a power supply unit 2-2, and a conductive slip ring 2-3; wherein the piezoelectric element 2-1 is a tiny vibration unit based on the principle of piezoelectric effect, and there are four of them, which are evenly distributed around the spindle 10; the power supply unit 2-2 is a non-contact power transmission unit based on the principle of loosely coupled electromagnetic induction, and there are four of them, which are symmetrically distributed around the spindle 10; the piezoelectric element 2-1, the spindle 10, and the tool 6 are transitionally matched, and the power supply unit 2-2 is clamped by the No. 1 chuck 4-1 and the No. 2 chuck 4-2, and the connection is a tight connection, and the fit is an interference fit; the vibration is generated by the piezoelectric element 2-1 and causes the tool 6 to produce instantaneous radial expansion and contraction, and in a relatively short time, causes the workpiece 5-2 and the abrasive particles of the tool 6 to collide repeatedly in a very short time in a high acceleration state; the spindle 10 does not transmit vibration, and the radial vibration is emitted by the piezoelectric elements 2-1 distributed in pairs.

Optionally, the piezoelectric element 2 - 1 is a piezoelectric ceramic, which realizes tiny vibrations by means of the piezoelectric effect and voltage effect principle of the piezoelectric ceramic.

The above-mentioned ultrasonic power supply is a self-excited ultrasonic generator, which is used to generate high-frequency sinusoidal AC signals. The ultrasonic power supply is installed behind the spindle base 4, fixed by screws, and is provided with a connecting line channel. The built-in motor of the spindle 10 is only used to realize the rotation of the tool 6. The high-frequency sinusoidal AC signal generated by the ultrasonic power supply is transmitted to the piezoelectric element 2-1 through the ultrasonic transmission device, so that the tool 6 generates tiny ultrasonic vibrations, thereby realizing ultrasonic vibration-assisted cutting of the workpiece 5-2.

The ultrasonic power supply, the piezoelectric element 2 - 1 and the power supply unit 2 - 2 are connected to each other via internal connecting wires. The piezoelectric element 2 - 1 is supplied with electric energy by the conductive slip ring 2 - 3 as it rotates with the main shaft 10 .

The above-mentioned No. 1 chuck 4-1 and the flange jointly clamp the ultra-thin diamond tool 6, so that it remains stable in the axial direction and has good rigidity; wherein, No. 1 chuck 4-1 has through holes in both axial and radial directions, and has connecting wires and conductive slip rings 2-3, and the connecting wires are responsible for connecting the power supply unit 2-2 and the piezoelectric element 2-1; No. 2 chuck 4-2 has an axial through hole, and has connecting wires, and the connecting wires are responsible for connecting the power supply unit 2-2 and the ultrasonic vibration motor.

In one embodiment of the present invention, the laser auxiliary module 1 includes a horizontal fixed rod 1-1, a first connecting rod 1-2, a laser 1-3, and a laser head 1-4. The laser auxiliary module 1 is connected to the spindle base 4 through the horizontal fixed rod 1-1 to ensure the stability of the processing process; the angle of the laser head 1-4 of the laser auxiliary module 1 can be adjusted through the first connecting rod 1-2; during the processing, the laser source continues to focus on the processing position along the processing path to implement laser-assisted softening, and the laser auxiliary module 1 moves synchronously with the spindle base 4.

The processing position of the laser focus and the cutting area are placed in the same micrometer-level circular area, and the laser 1-3 and the tool 6 are fed in the same direction, so that the geometric position relationship between the tool 6 and the laser focus is always kept constant.

The above lasers 1-3 are pulse lasers with a wavelength of 1064nm and a power adjustable within the range of 50 to 150W.

The output of the above-mentioned lasers 1-3 is femtosecond or picosecond laser.

In one embodiment of the present invention, the detection module 3 includes a camera 3-1, a temperature sensor 3-2, a connecting member 3-3, a Y-axis slide rail 3-4 and a second connecting member 3-5. The camera 3-1 in the detection module 3 moves on the Y-axis slide rail 3-4. The Y-axis slide rail 3-4 is used to adjust the position of the camera 3-1 relative to the workpiece 5-2. The angle of the camera 3-1 of the detection module 3 can be adjusted through the connecting member 3-3.

The camera 3 - 1 is a CCD camera, which can record the movement trajectory and feed amount of the tool 6 .

Optionally, the detection module can be remotely connected to an industrial computer to observe the cutting trajectory and cutting temperature in real time and implement closed-loop control thereof.

Example 2

An embodiment of the present invention provides a processing method for wafer cutting combining laser and ultrasonic dual-assisted wafer cutting, comprising the following steps:

Step 1, sticking a film on the back of the workpiece 5-2; the film is a UV film or a blue film;

Step 2: Fix the workpiece 5-2 with a fixing fixture 5-1;

Step 3: Input the motion trajectory parameters of the tool 6 and the carrier 5 into the industrial computer;

Step 4: Adjust the relative position between the workpiece 5-2 and the laser 1-3, and focus the laser beam on the processing position surface of the workpiece 5-2 and the tool 6; the processing position of the workpiece 5-2 is to the brittle-plastic critical state;

Step 5: The piezoelectric element 2 - 1 vibrates, and the tool 6 vibrates radially; the piezoelectric elements 2 - 1 are evenly distributed around the spindle 10 , and the vibrations cancel each other out, and do not affect the rotation of the spindle 10 ;

Step six: the tool 6 cuts the workpiece 5 - 2 .

During the above cutting process, the spindle base 4 and the laser auxiliary module 1 do not rotate along with the spindle 10 .

In order to protect the workpiece 5-2 from external damage during the cutting process, it is necessary to apply a film on the surface of the workpiece 5-2 in advance; during the cutting process of the tool 6, the film should be attached to the back of the workpiece 5-2, and the film should be in close contact with the fixing fixture 5-1.

The above-mentioned fixing fixture 5-1 is a vacuum suction cup, which can stably hold the adsorbed workpiece 5-2.

It should be noted that due to the great friction during cutting, deionized water should be sprayed continuously from all directions of the workpiece 5-2; when the temperature of the processing area detected by the temperature sensor 3-2 of the detection module 3 exceeds the critical plastic brittle temperature of the workpiece 5-2, the industrial computer issues a command to continuously spray deionized water on the processing area to avoid thermal damage.

The thickness of the cutter 6 must be uniform and must not exceed the width of the scribe groove.

In the ultra-precision cutting process, for hard and brittle materials such as single crystal silicon, there are two different removal modes, namely brittle mode and plastic mode, as the thickness of the undeformed chips changes. If the removal is carried out in the brittle mode, defects such as cracks and pits will appear on the processed surface, seriously affecting the processing quality and performance of single crystal silicon.

The purpose of the above-mentioned pre-slicing force test on the sample is to determine the size of the cutting force and the critical brittle-ductile transition depth. Specifically, while the three-axis machining platform drives the single-point diamond tool to cut the sample, a laser beam is applied to irradiate the workpiece at the same time. After processing, the sample is measured for the size of the cutting force using a precision detection instrument, and the degree of sub-surface loss of the wafer cutting edge is observed using a scanning electron microscope.

An embodiment of the present invention provides a laser-assisted processing technology. In the laser preheating-assisted processing, the irradiation point of the laser beam is made several millimeters lower than the center of the tool 6, so as to avoid the problem of too large heat-affected zone in the existing laser preheating-assisted processing method. The center of the tool 6 needs to be flush with the center of the end face of the workpiece 5-2, so that the laser heating point is always lower than the center of the workpiece 5-2, thereby effectively achieving the heating and softening effect when processing the central area of the workpiece 5-2; during the processing process, the laser heating action area is as close to the cutting area as possible, so that the heat-affected zone is minimized.

The above-mentioned laser heads 1-4 can be focused in front of the tool 6, which solves the problem of single feed direction processing, achieves high-quality processing and shortens the processing time of complex paths; at the same time, this processing method overcomes the structural interference limitation of the tool 6, and can make the laser emission point close to the cutting edge of the tool 6 and can be flexibly adjusted, thereby realizing the laser online preheating auxiliary heating effect controlled by different parameters.

The embodiment of the present invention provides an ultrasonic vibration-assisted processing technology, which changes the contact state between the tool 6 and the workpiece 5-2 during the cutting process; through the instantaneous radial vibration of the tool 6, the abrasive particles and the workpiece 5-2 are frequently collided at high speed, thereby enhancing the grinding effect of the cutting process and introducing an innovative processing mechanism; the application of this technology can effectively reduce the energy consumption of cutting processing, improve processing efficiency, and at the same time reduce heat generation, which helps to prevent deformation and damage to the workpiece surface.

The ultrasonic vibration-assisted processing technology improves the cooling effect of the abrasive particles; under the action of vibration, a small gap is formed between the tool 6 and the workpiece 5-2, preventing the occurrence of phenomena such as pore blockage and abrasive particle passivation, further improving the processing stability and quality, promoting the flow of coolant, effectively taking away the heat generated during the processing, preventing the abrasive particles from overheating and passivation, and thus extending the service life of the tool 6.

An embodiment of the present invention provides a processing method for combining laser and ultrasonic dual-assisted wafer cutting. The processing method innovatively integrates laser-assisted diamond cutting technology and ultrasonic vibration-assisted processing technology, and accurately focuses the laser on the processing surface of the workpiece 5-2, so as to achieve ultra-precision processing of difficult-to-process hard and brittle materials; the resonant frequency of ultrasonic vibration is automatically tracked to make the cutting process more stable and thorough, which can solve the problem of micro-crack propagation caused by instantaneous high temperature of local heating during laser-assisted cutting, thereby improving the cutting quality and surface finish.

Compared with the prior art, the present invention, on the one hand, realizes the improvement of the critical plastic-brittle transition depth of hard and brittle materials such as single crystal silicon through laser-assisted diamond cutting technology, and at the same time, through ultrasonic vibration, causes the tool 6 to vibrate radially instantaneously, so that the contact state between the tool 6 and the workpiece 5-2 changes, thereby effectively reducing the sub-surface damage of the workpiece 5-2, improving the processing quality of the workpiece 5-2, and extending the service life of the tool 6.

Claims (10)

1. A dual auxiliary wafer dicing apparatus combining laser and ultrasound, comprising: the ultrasonic vibration device comprises a Z-axis moving mechanism (7-1), an X-axis moving mechanism (7-2), a portal frame (8), a Y-axis moving mechanism (9), a main shaft base (4), a main shaft (10), a cutter (6), a bearing table (5) and an ultrasonic vibration auxiliary module (2); the cutter (6) is arranged on the main shaft (10);

The ultrasonic vibration auxiliary module (2) comprises: an ultrasonic power supply, a piezoelectric element (2-1), a power supply unit (2-2) and a conductive slip ring (2-3);

The piezoelectric element (2-1) is arranged between the cutter (6) and the main shaft (10);

The number of the piezoelectric elements (2-1) is 2 or more, and the piezoelectric elements are uniformly distributed around the spindle (10).

2. The dual assist laser and ultrasonic wafer dicing apparatus as recited in claim 1, wherein: the cutter (6) is a hub type cutter and is in transition fit with the piezoelectric element (2-1) and the main shaft (10).

3. The dual assist laser and ultrasonic wafer dicing apparatus as recited in claim 2, wherein: the spindle base (4) is arranged on the portal frame (8) by the Z-axis moving mechanism (7-1) and the X-axis moving mechanism (7-2), the spindle base (4) is controlled to move, the bearing table (5) is a rotary table, and the bearing table is arranged on the Y-axis moving mechanism (9).

4. A combined laser and ultrasonic dual assist wafer dicing apparatus according to claim 1, 2 or 3, characterized in that: the laser processing device is also provided with a laser auxiliary module (1) which is fixed on the main shaft base (4), and laser emitted by the laser heads (1-4) of the laser auxiliary module (1) is focused at the processing position of the cutter (6).

5. The dual assist laser and ultrasonic wafer dicing apparatus as recited in claim 4, wherein: the lasers (1-3) are pulse lasers, and output femtosecond or picosecond lasers.

6. The dual assist laser and ultrasonic wafer dicing apparatus of claim 5, wherein: the laser wavelength is 1064nm, and the power of the laser (1-3) is 50-150W; the rotating speed of the main shaft (10) is 12000rpm, and the power is 2.0-2.2 KW.

7. The dual assist laser and ultrasonic wafer dicing apparatus as recited in claim 6, wherein: also provided with a detection module (3).

8. The dual assist laser and ultrasonic wafer dicing apparatus as recited in claim 4, wherein: the detection module comprises a camera (3-1) and a temperature sensor (3-2).

9. A processing method combining laser and ultrasonic dual auxiliary wafer cutting comprises the following steps: a combined laser and ultrasonic dual assist wafer dicing apparatus as recited in claim 4;

1) Sticking an adhesive film on the back surface of the workpiece (5-2); the adhesive film is a UV film or a blue film;

2) Fixing the workpiece (5-2) by using a fixing clamp (5-1);

3) Inputting motion track parameters of a cutter (6) and a bearing table (5) into an industrial personal computer;

4) Adjusting the relative positions of the workpiece (5-2) and the laser (1-3), and focusing the laser beam on the surfaces of the processing positions of the workpiece (5-2) and the cutter (6); the processing part of the workpiece (5-2) reaches a brittle plastic critical state;

5) The piezoelectric element (2-1) vibrates, and the cutter (6) vibrates radially; the piezoelectric elements (2-1) are uniformly distributed around the main shaft (10), and the vibrations cancel each other out, so that the rotation of the main shaft (10) is not affected;

6) The tool (6) cuts the workpiece (5-2).

10. The method for processing the wafer dicing with the combination of laser and ultrasonic dual assistance according to claim 9, wherein: deionized water is continuously sprayed from all directions of the workpiece (5-2) during the processing.