CN117747516B

CN117747516B - Wafer feeding device

Info

Publication number: CN117747516B
Application number: CN202410182780.XA
Authority: CN
Inventors: 陆敏杰; 王兆昆
Original assignee: Wuxi Xivi Technology Co ltd
Current assignee: Wuxi Xivi Technology Co ltd
Priority date: 2024-02-19
Filing date: 2024-02-19
Publication date: 2024-05-03
Anticipated expiration: 2044-02-19
Also published as: CN117747516A

Abstract

The invention discloses a wafer feeding device, which belongs to the technical field of semiconductor transmission, and comprises a base, wherein a manipulator, a turntable and a detection mechanism are sequentially arranged on the base in the horizontal direction, at least two alignment parts are arranged on the turntable, the alignment parts can bear wafers, any alignment part can reach the lower part of the detection mechanism, each alignment part comprises a base, a groove is arranged at the upper end of the base, a supporting head is arranged in the groove, the upper end of the supporting head is connected with a sucking disc, clamping strips are arranged on the side of the supporting head in a surrounding manner, clamping grooves for accommodating the clamping strips are formed in the base, and the clamping strips are elastic parts. The invention has reasonable layout, can improve the stability of the wafer conveying process and improves the wafer feeding efficiency.

Description

Wafer feeding device

Technical Field

The invention relates to the technical field of semiconductor conveying, in particular to a wafer feeding device.

Background

With the rapid development of the semiconductor industry, the feature size of the integrated circuit is continuously miniaturized, the semiconductor chip is continuously developed towards the small volume, high circuit density, high speed and low power consumption, and the integrated circuit is now in the submicron technology stage of a very large scale integrated circuit (UltraLargeScaleIntegration, abbreviated as ULSI), wherein the wafer is a basic base material, a required circuit is etched on the wafer according to the requirement, and then the wafer is divided into small chips.

Semiconductors often require different handling of wafers by different processing equipment during the manufacturing process. The feeding and positioning of the wafer is a very critical link, and if the feeding position of the wafer is incorrect, the uniformity of the etching process or the coating process of the wafer is deteriorated, so that the yield is reduced. In the existing semiconductor device, the wafer loading area, the wafer output area and other process areas are not in a straight line due to space arrangement, so that the wafer box of the loading area or the wafer box of the output area needs to be connected to a clamping position of a manipulator, and the existing process often realizes the transfer of the position of the wafer box through a transferring clamping mechanism. The clamping mechanism arranged in this way can enable the whole layout of the device to occupy a large space, and meanwhile, the operation process is complex, and the transfer efficiency of the wafer is affected.

Japanese patent application publication No. JP2012022411 discloses a grinding device comprising a plurality of chuck tables, each chuck having a holding surface for holding and holding a wafer, each grinding device having a grinding wheel for grinding sucked and held on the holding surface of the chuck table, grinding feed means in a grinding feed direction perpendicular to the holding surface of the chuck table, each grinding feed means, and loading means for loading an unground wafer to a fixed surface of the chuck table. The polishing apparatus further comprises detecting means for detecting an unground wafer to be loaded into the chuck by the loading means, and control means for determining a type of the wafer detected by the detecting means and selecting a polishing condition according to the determined type of the wafer. The device can grind a plurality of different types of wafers under proper grinding conditions according to the types of the wafers when grinding the plurality of wafers. However, there is room for improvement in the following technology: the wafer can have the skew when the arm is placed on the chuck to the wafer, leads to the wafer slope in the grinding process for grind inhomogeneous, the location in the wafer pay-off in-process simultaneously also can lead to the manipulator can not be fast, accurately clamp the wafer, finally leads to the wafer impaired.

Disclosure of Invention

The invention aims to provide a wafer feeding device with high-efficiency feeding capability.

In order to solve the technical problems, the invention specifically provides the following technical scheme:

The wafer feeding device comprises a base, wherein a manipulator, a rotary table and a detection mechanism are sequentially arranged on the base in the horizontal direction, at least two alignment members are arranged on the rotary table, the alignment members can bear wafers, and any alignment member can reach the lower part of the detection mechanism. In the initial state, one of the alignment parts on the turntable is positioned at a designated loading position, the wafer is clamped to the alignment part at the designated loading position through the manipulator, after the alignment part bears the wafer, the turntable rotates to convey the wafer to the lower part of the detection mechanism for qualified parameter detection, meanwhile, the other alignment part on the turntable reaches the designated position, the manipulator repeats the previous loading action to enable the other alignment part to bear the wafer, the turntable further rotates, the detected wafer returns to the initial loading position, the manipulator conveys the detected wafer to leave the turntable, the previous loading action is repeated, the loading and unloading are realized by using one manipulator, the loading position and the unloading position of the manipulator are kept consistent, on one hand, the positioning difficulty of the manipulator is reduced, the loading efficiency of the manipulator is improved, the less positioning is beneficial to reducing the load of the manipulator, the service life is prolonged, on the other hand, the manipulator is matched with the turntable to rotate to realize the loading and unloading, the occupation space of the whole layout of the device is reduced, and the device has applicability in different places.

Preferably, the alignment member comprises a base, a groove is formed in the upper end of the base, a supporting head is arranged in the groove, a sucker is connected to the upper end of the supporting head, a clamping strip is arranged on the side of the supporting head in a surrounding mode, a clamping groove for accommodating the clamping strip is formed in the base, and the clamping strip is an elastic member. When the sucking disc is accepted the wafer, the wafer probably has the slope to the sucking disc relatively, the part of wafer contacts the sucking disc earlier this moment, take place the slope after the sucking disc part is pressed, the sucking disc passes through the card strip of supporting head extrusion slope one side for the sucking disc slope and laminating with the wafer bottom, the wafer is unclamped again to the manipulator this moment, realize the stable absorption of sucking disc to the wafer, resume deformation after card strip elasticity is pressed, make sucking disc and wafer keep horizontal gesture, prevent that the wafer from loading in-process landing probably, be favorable to the stability of transportation, the detection validity of detection subassembly has been guaranteed in the horizontal correction of wafer simultaneously, detection efficiency has been improved, the carousel is at the rotation in-process, card strip passes through elastic deformation, can absorb the vibrations interference that the base member passed to the supporting head, improve the stability of wafer on the sucking disc.

Preferably, the bottom of the supporting head is a spherical surface, a spacing distance exists between the side wall of the supporting head and the side wall of the groove, the bottom of the sucker can swing in the groove, the middle parts of the supporting head and the sucker are provided with air holes, and the air holes are used for connecting an air pump. After the air pump is started, air flows outwards from the air holes through suction, so that the suction force of the suction cup on the wafer is realized, and the spacing distance between the supporting head and the groove is convenient for the supporting head to swing on one hand so that the suction cup is attached to the wafer.

Preferably, one end of the clamping groove is communicated with the groove, the other end of the clamping groove is communicated with the adjusting hole, the adjusting hole is communicated to the upper end of the base, the adjusting column is axially and slidably arranged in the adjusting hole, the clamping strip is provided with a sealing ring matched with the clamping groove, and the clamping strip can move in the clamping groove. When the manipulator places the wafer on the sucking disc, the center of wafer and the center of sucking disc probably do not overlap, lead to the sucking disc to receive the offset load power to one side skew, the sucking disc drives the card strip through the supporting head of bottom and slides to regulation hole one side in the draw-in groove, the card strip of sliding extrudees the air in the regulation hole through the sealing washer, make the regulation downthehole atmospheric pressure of regulation post below increase, thereby jack-up regulation post, make the wafer is raised to the regulation post of this side, simultaneously, the card strip of opposite side slides to the draw-in groove, make the regulation post of offside descend, thereby make the whole reverse slip of wafer to eccentric one side, after the center of wafer aligns with the center of sucking disc, the chuck no longer receives the offset load pressure, the initial height is restoreed to the regulation post of both sides, the wafer steadily keeps in the sucking disc top, the automatic adjustment to wafer alignment has been realized, feeding stability has been improved, simultaneously, the wafer alignment is favorable to realizing the detection mechanism on the one hand to the wafer accuracy, on the other hand improves the success rate of wafer after the manipulator snatchs the detection, the wafer is avoided the manipulator to press from getting the possibility of damaging of wafer that the offset.

Preferably, the wafer cassette is arranged on one side of the manipulator on the base, the wafer is stacked in the wafer cassette, and the manipulator can transfer the wafer in the wafer cassette to a similar alignment piece.

Preferably, the base is provided with a collection warehouse at the other side of the manipulator, the collection warehouse and the crystal box are arranged at the opposite sides of the manipulator, and the manipulator can transfer the detected wafers to the collection warehouse. The arrangement mode of the crystal box and the collection warehouse on the two sides of the manipulator enables the manipulator to carry out feeding and discharging work on the crystal box, the alignment piece and the collection warehouse, the moving stroke of the manipulator is reduced, the abrasion and the energy consumption of the manipulator are reduced, the use cost and the maintenance cost are saved, and the wafers are sent from the crystal box, the feeding, the detection and the discharging processes are carried out through the U-shaped route, and the overall layout occupation space of the feeding device is reduced.

Preferably, the base is provided with a mounting groove, the center of the bottom of the turntable is connected with a shaft body, a motor for driving the shaft body to rotate is arranged in the mounting groove, a stabilizing component is further arranged in the mounting groove, the stabilizing component comprises a sleeve body connected with the shaft body, and a plate body capable of being in contact with the sleeve body is arranged in the mounting groove. The plate body is contacted with the shaft body, so that correction can be formed on the rotation of the shaft body, the possibility of excessive shaking in the rotating process of the turntable is reduced, the posture of the wafer is stabilized, and the detection accuracy of the wafer and the stability of the wafer taken and put by the manipulator are improved.

Compared with the prior art, the invention has the following beneficial effects: the arrangement of the manipulator, the turntable and the detection mechanism reduces the positioning difficulty of the manipulator and improves the service life of the manipulator; the feeding and the discharging of the wafers are realized by means of the same manipulator, the stroke range of the manipulator is small, the manufacturing cost is reduced, the energy consumption of the manipulator is also reduced, and the feeding efficiency is improved; the sucker can elastically swing, so that stable adsorption is realized on wafer lamination, and the possibility of slipping in the wafer transferring process is reduced; the clamping strips can absorb vibration interference through compression deformation, so that the positioning stability of the wafer is improved; when the wafer deviates on the sucker, the lifting of the plurality of adjusting columns can be realized by extruding the clamping strips, so that the automatic calibration of the wafer position is realized, the positioning accuracy of the wafer is improved, and the quick blanking of the mechanical arm and the accurate detection of the detection mechanism are facilitated; the clamping strips raise and lower the adjusting columns in a mode of increasing air pressure, so that wafer alignment can be realized without consuming electric energy, and the cost is reduced; the wafer box, the collection warehouse and the turntable are arranged in three adjacent directions of the manipulator, so that the wafers are transmitted in a U-shaped path, the overall layout occupation space of the device is optimized, and the applicability of the device in different places is improved; the stable component contacts the sleeve body through the plate body, so that the rotating gesture of the turntable is stabilized, and the phenomenon that the wafer is positioned inaccurately due to shaking is avoided, and the feeding efficiency is influenced. Therefore, the invention is a wafer feeding device with high-efficiency feeding capability.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below. It will be apparent to those of ordinary skill in the art that the drawings in the following description are exemplary only and that other implementations can be obtained from the extensions of the drawings provided without inventive effort.

FIG. 1 is an overall schematic diagram of a wafer feeder;

FIG. 2 is a schematic top view of a wafer feeder;

FIG. 3 is a schematic layout of an alignment member;

FIG. 4 is a schematic cross-sectional view of an alignment member;

FIG. 5 is a schematic view of an alignment member in semi-section;

FIG. 6 is a schematic view of a clamping bar and a sealing ring;

FIG. 7 is a schematic cross-sectional view of a mounting slot;

Fig. 8 is a schematic top view of a stabilization assembly.

Reference numerals: a base 1; a mounting groove 10; a manipulator 2; a turntable 3; a detection mechanism 4; an alignment member 5; a base 50; a groove 51; a support head 52; suction cups 53; a clip strip 54; a card slot 55; an adjustment aperture 56; an adjustment post 57; a seal ring 58; a cassette 6; a collection library 7; a shaft body 8; a stabilizing assembly 9; a sleeve 90; an extension plate 91; a buffer sleeve 92; an elastic plate 93; a through hole 94; flow holes 95.

Detailed Description

The technical scheme of the invention is further described in detail below with reference to the specific embodiments and the attached drawings:

It will be apparent that the described embodiments are only some, but not all, embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

Referring to fig. 1-3, a wafer feeding device comprises a base 1, wherein a manipulator 2, a turntable 3 and a detection mechanism 4 are sequentially arranged on the base 1 in the horizontal direction, at least two alignment members 5 are arranged on the turntable 3, the alignment members 5 can bear wafers, any alignment member can reach the lower part of the detection mechanism 4, and the detection mechanism 4 is used for detecting the wafers below.

In the initial state, one of the alignment pieces 5 on the turntable 3 is located at a designated loading position, the wafer is clamped to the alignment piece 5 at the designated loading position through the manipulator 2, after the alignment piece 5 bears the wafer, the turntable 3 rotates to convey the wafer to the lower part of the detection mechanism 4 for qualified parameter detection, meanwhile, the other alignment piece 5 on the turntable 3 reaches the designated position, the manipulator 2 repeats the previous loading action, the other alignment piece 5 bears the wafer, the turntable 3 further rotates, the detected wafer returns to the initial loading position, the manipulator 2 conveys the detected wafer to leave the turntable 3, the previous loading action is repeated, loading and unloading are realized by using one manipulator 2, and the loading position and the unloading position of the manipulator 2 are kept consistent.

Referring to fig. 4-6, the alignment member 5 includes a base 50, a groove 51 is provided at an upper end of the base 50, a supporting head 52 is provided in the groove 51, a suction cup 53 is connected to an upper end of the supporting head 52, a clamping strip 54 is provided around a side of the supporting head 52, the base 50 is provided with a clamping groove 55 for accommodating the clamping strip 54, and the clamping strip 54 is an elastic member.

When the sucker 53 receives the wafer, the wafer may incline relative to the sucker 53, at this moment, the part of the wafer contacts the sucker 53 firstly, the sucker 53 is inclined after being partially pressed, the sucker 53 extrudes the clamping strip 54 at one inclined side through the supporting head 52, so that the sucker 53 inclines and is attached to the bottom of the wafer, at this moment, the manipulator 2 loosens the wafer again, stable adsorption of the sucker 53 to the wafer is realized, the clamping strip 54 is elastically pressed and then recovers deformation, so that the sucker 53 and the wafer keep horizontal postures, the wafer is prevented from falling off in the feeding process, the stability in the transportation process is facilitated, meanwhile, the detection effectiveness of the detection assembly is guaranteed through horizontal correction of the wafer, the detection efficiency is improved, the clamping strip 54 can absorb vibration interference transmitted to the supporting head 52 through an elastic deformation in the rotating process, and the stability of the wafer on the sucker 53 is improved.

The bottom of the supporting head 52 is a spherical surface, a spacing distance exists between the side wall of the supporting head 52 and the side wall of the groove 51, the bottom of the sucker 53 can swing in the groove 51, air holes are formed in the middle of the supporting head 52 and the sucker 53, and the air holes are used for being connected with an air pump.

After the air pump is started, air flows outwards from the air holes through suction, so that the suction force of the suction cup 53 on the wafer is realized, and the spacing distance between the supporting head 52 and the groove 51 is convenient for the supporting head 52 to swing on one hand, so that the suction cup 53 is attached to the wafer.

One end of the clamping groove 55 is communicated with the groove 51, the other end of the clamping groove 55 is communicated with the adjusting hole 56, the adjusting hole 56 is communicated to the upper end of the base 50, an adjusting column 57 is axially arranged in the adjusting hole 56 in a sliding mode, the top end of the adjusting column 57 is located above the top end of the sucker 53, the clamping strip 54 is provided with a sealing ring 58 matched with the clamping groove 55, and the clamping strip 54 can move in the clamping groove 55.

When the wafer is placed on the sucker 53 by the manipulator 2, the center of the wafer and the center of the sucker 53 may not overlap, so that the sucker 53 is biased to one side by a bias load force, the sucker 53 drives the clamping strip 54 to slide to one side of the adjusting hole 56 in the clamping groove 55 through the supporting head 52 at the bottom, the sliding clamping strip 54 presses air in the adjusting hole 56 through the sealing ring 58, so that the air pressure in the adjusting hole 56 below the adjusting column 57 is increased, the adjusting column 57 is jacked up, the adjusting column 57 at the side is lifted up, meanwhile, the clamping strip 54 at the opposite side slides to the clamping groove 55, the adjusting column 57 at the opposite side is lowered, so that the wafer is reversely slid to the eccentric side, until the center of the wafer is aligned with the center of the sucker 53, the clamping column 57 at the two sides is not biased to be pressed, the initial height is restored, the wafer is stably kept above the sucker 53, the wafer is accurately aligned, the automatic adjustment is realized, the feeding stability is improved, the alignment of the wafer is favorable for realizing the detection mechanism 4 to detect the wafer, and the wafer 2 is prevented from being damaged after the wafer is clamped by the manipulator 2.

The susceptor 1 is provided with a cassette 6 at one side of the robot 2, wafers are stacked in the cassette 6, and the robot 2 can transfer the wafers in the cassette 6 to a similar alignment member 5.

Referring to fig. 1 and 2, a collecting base 7 is disposed on the other side of the robot 2, the collecting base 7 and the wafer cassette 6 are disposed on opposite sides of the robot 2, and the robot 2 can transfer the inspected wafers to the collecting base 7.

The crystal box 6 and the collection warehouse 7 are arranged on two sides of the manipulator 2, so that the manipulator 2 performs feeding and discharging work on the crystal box 6, the alignment piece 5 and the collection warehouse 7, the moving stroke of the manipulator 2 is reduced, the abrasion and the energy consumption of the manipulator 2 are reduced, the use cost and the maintenance cost are saved, and the wafers are sent out from the crystal box 6, the feeding, detecting and discharging processes are performed through the U-shaped route, and the overall layout occupation space of the feeding device is reduced.

Referring to fig. 7 and 8, a mounting groove 10 is formed in the base 1, a shaft body 8 is connected to the center of the bottom of the turntable 3, a motor for driving the shaft body 8 to rotate is arranged in the mounting groove 10, a stabilizing assembly 9 is further arranged in the mounting groove 10, the stabilizing assembly 9 comprises a sleeve body 90 connected to the shaft body 8, and a plate body capable of being in contact with the sleeve body 90 is arranged in the mounting groove 10.

The plate body is contacted with the shaft body 8, so that correction can be formed on the rotation of the shaft body 8, the possibility of excessive shaking in the rotating process of the turntable 3 is reduced, the posture of the wafer is stabilized, and the detection accuracy of the wafer and the stability of the wafer taken and placed by the manipulator 2 are improved.

The cover body 90 includes two at least extension boards 91, the plate body is including setting up in the buffer cover 92 of extension board 91 one side, one of them buffer cover 92 is laid in the one side that the axis body 8 is close to detection mechanism 4, the buffer cover 92 is including the terminal surface of keeping away from axis body one side, the terminal surface is fixed with the lateral wall of mounting groove 10, the buffer cover 92 is still including the elastic plate 93 near the one side of axis body 8, the protruding bending of axis body 8 in elastic plate 93 middle part, the upper and lower both ends of buffer cover 92 seal and the middle part exists the cavity, the through-hole 94 of intercommunication cavity has been seted up to the upper end of buffer cover 92, be equipped with the circulation hole 95 of external circulation in the mounting groove 10, carousel 3 carries when alignment spare 5 arrives detection mechanism 4 below, the extension board 91 of axis body 8 side can contact and extrusion elastic plate 93.

The motor drives the sleeve body 90 to rotate synchronously when the shaft body 8 rotates, when the turntable 3 rotates to enable the alignment part 5 to reach the lower side of the detection mechanism 4, the turntable 3 stops rotating, the detection mechanism 4 detects the wafer, the alignment part 5 moves to the lower side of the detection mechanism 4, the extension plate 91 can contact and press the elastic plate 93, thereby rotating and decelerating before the turntable 3 stops rotating and positioning, decelerating and buffering before the turntable 3 is realized, and similarly, the extrusion force of the elastic plate 93 which bends outwards in the middle part to the extension plate 91 is gradually reduced when the turntable 3 starts to enable the detected wafer to reach the blanking position, thereby realizing slow starting of the turntable 3.

Meanwhile, when the extension plate 91 contacts the elastic plate 93, the elastic plate 93 can absorb the vibration of the rotating shaft in the rotating process through deformation of the elastic plate, so that the stability of the wafer on the turntable 3 is further improved, and the stability of the feeding process is further improved.

Simultaneously, as the motor generates heat in the driving process, heat is transferred to the turntable 3 through the rotating shaft, and the elastic plate 93 is contacted with the extending plate 91, so that the heat is transferred to the elastic plate 93 through the rotating shaft, the sleeve body 90 and the extending plate 91, thereby being beneficial to reducing the influence of the heat on the turntable 3 and the wafer and ensuring the reality and reliability of detection data.

When the extension board 91 is close to the elastic board 93, the elastic board 93 is pressed and deformed and extrudes the air in the buffer sleeve 92, the air in the buffer sleeve 92 is output upwards from the through hole 94 at the top and acts on the rotary table 3, the air flow acts on the rotary table 3 and flows downwards and flows outwards from the circulation hole 95, cooling and heat exchange of hot air in the mounting groove 10 are realized, the service lives of the rotary shaft and the motor are prolonged on one hand, heat dissipation to the bottom of the rotary table 3 is realized on the other hand, heat is further prevented from being transferred upwards to the wafer on the alignment piece 5, and detection data of the detection mechanism 4 are influenced.

It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.

Claims

1. The wafer feeding device comprises a base (1), wherein the base (1) is sequentially provided with a manipulator (2), a turntable (3) and a detection mechanism (4) in the horizontal direction,

The wafer alignment device is characterized in that at least two alignment pieces (5) are arranged on the turntable (3), the alignment pieces (5) can bear wafers, the alignment pieces (5) are located below the detection mechanism (4), each alignment piece (5) comprises a base (50), a groove (51) is formed in the upper end of each base (50), a supporting head (52) is arranged in each groove (51), a sucker (53) is connected to the upper end of each supporting head (52), clamping strips (54) are arranged on the side of each supporting head (52) in a surrounding mode, clamping grooves (55) for accommodating the corresponding clamping strips (54) are formed in the corresponding bases (50), and the corresponding clamping strips (54) are elastic pieces.

2. The wafer feeding apparatus according to claim 1, wherein: the bottom of supporting head (52) is the sphere, there is the interval distance between supporting head (52) lateral wall with recess (51) lateral wall, the bottom of sucking disc (53) can be in swing in recess (51), the gas pocket is seted up at supporting head (52) and sucking disc (53) middle part, the gas pocket is used for connecting the air pump.

3. The wafer feeding apparatus according to claim 1, wherein: the clamping groove (55) is characterized in that one end of the clamping groove (55) is communicated with the groove (51), the other end of the clamping groove (55) is communicated with the adjusting hole (56), the adjusting hole (56) is communicated to the upper end of the base (50), an adjusting column (57) is axially and slidably arranged in the adjusting hole (56), the clamping strip (54) is provided with a sealing ring (58) matched with the clamping groove (55), and the clamping strip (54) can move in the clamping groove (55).

4. The wafer feeding apparatus according to claim 1, wherein: the wafer alignment device is characterized in that a wafer box (6) is arranged on one side of the manipulator (2) in the base (1), the wafer is stacked in the wafer box (6), and the manipulator (2) can transfer the wafer in the wafer box (6) onto the alignment piece (5).

5. The wafer feeding apparatus according to claim 4, wherein: the wafer collecting device is characterized in that a collecting warehouse (7) is arranged on the other side of the manipulator (2) by the aid of the base (1), the collecting warehouse (7) and the wafer boxes (6) are arranged on two opposite sides of the manipulator (2), and the manipulator (2) can transfer detected wafers to the collecting warehouse (7).

6. The wafer feeding apparatus according to claim 4, wherein: the base (1) is equipped with mounting groove (10), carousel (3) bottom center is connected with axis body (8), be equipped with the drive in mounting groove (10) axis body (8) rotatory motor still be equipped with in mounting groove (10) stable subassembly (9), stable subassembly (9) including connect in the cover body (90) of axis body (8), be equipped with in mounting groove (10) can with the plate body of cover body (90) contact.