CN114454093B

CN114454093B - Step-by-step wafer positioning and supporting device

Info

Publication number: CN114454093B
Application number: CN202111207081.9A
Authority: CN
Inventors: 许剑锋; 郑正鼎; 张建国; 于世超; 侍大为
Original assignee: Huazhong University of Science and Technology
Current assignee: Huazhong University of Science and Technology
Priority date: 2021-10-15
Filing date: 2021-10-15
Publication date: 2022-12-27
Anticipated expiration: 2041-10-15
Also published as: CN114454093A

Abstract

The invention discloses a step-by-step wafer positioning and supporting device, which comprises a driving device, a supporting device and a positioning device, wherein the driving device, the supporting device and the positioning device are uniformly distributed on a bottom plate, the driving device comprises a stepping motor and a pulling plate, the positioning device comprises a positioning finger mounting frame and a floating positioning finger, one end of the pulling plate is connected with the stepping motor, the other end of the pulling plate is connected with the floating positioning finger, the pulling plate is connected with the supporting device in a floating mode, the stepping motor moves in the forward direction to drive the floating positioning finger to move inwards in the radial direction of a wafer, the centering of the wafer is realized, the stepping motor continuously moves in the forward direction, the pulling plate drives the supporting device to move in the radial direction, and the supporting device supports the wafer after being tightened. The invention adopts three stepping motors to simultaneously operate the positioning and lifting devices arranged at 120 degrees, thereby ensuring high synchronism and positioning accuracy. When the wafer is placed, the floating positioning fingers firstly contact the placing platform, so that the stroke of the free falling body of the wafer is greatly reduced, the placing deviation is reduced, the impact force of contact is relieved, and the wafer is prevented from being damaged.

Description

Step-by-step wafer positioning and supporting device

Technical Field

The invention belongs to the technical field of wafer manufacturing, and particularly relates to a step-by-step wafer positioning and supporting device.

Background

In the process of polishing the wafer, the wafer needs to be moved to a grinding table station from a preparation station for grinding, the wafer needs to be accurately fixed on the grinding table in position so as to be beneficial to subsequent grinding work, in the process of moving the wafer to the station, a clamping tool needs to be used, in order to enable the wafer to be accurately located at the central position of the clamping tool, the wafer needs to be centered at first, due to the fact that the size of the wafer per se has an error and the wafer is placed on the preparation station, the high-precision wafer cannot be coincided with the center of the clamping tool, in addition, the wafer has the material characteristics of wafer raw materials, the wafer per se is fragile, the force of the clamping tool acting on the wafer is not easy to control, damage can occur in the wafer transferring process, and the yield is reduced.

Disclosure of Invention

The purpose of the invention is as follows: aiming at the defects in the prior art, the invention aims to provide a step-by-step wafer positioning and supporting device which is simple to operate, accurate in positioning and not easy to damage wafers when clamping and placing the wafers.

The technical scheme is as follows: in order to achieve the purpose of the invention, the technical scheme adopted by the invention is as follows:

the utility model provides a step by step wafer location and hold up device, includes drive arrangement, the device and the positioner of holding up of equipartition on the bottom plate, drive arrangement includes step motor and arm-tie, and positioner indicates the mounting bracket and float the location including the location and indicate, step motor is connected to arm-tie one end, and the other end indicates the mounting bracket through the location and connects the location of floating and indicate, and the arm-tie is floated simultaneously and connects the device of holding up, and step motor forward motion drives the location of floating and indicates along the radial inward movement of wafer, realizes the wafer centering, and step motor lasts forward motion, and the arm-tie drives the device of holding up and moves to the heart, holds up the device and lifts the wafer after tightening up.

Preferably, the driving device, the supporting device and the positioning device are at least provided with 3 groups, the driving device, the supporting device and the positioning device are uniformly arranged on the circumference at intervals, the tail end of the positioning finger installation frame is provided with one floating positioning finger, or the tail end of the positioning finger installation frame is provided with two floating positioning fingers in parallel, and the supporting device is arranged between the two floating positioning fingers.

Preferably, the stepping motor is connected with the pulling plate through a screw rod.

Preferably, the outer side of the pulling plate is provided with a hook plate, the hook plate is connected with the positioning finger mounting frame through a driving spring, and when the pulling plate moves centripetally, the driving spring is stretched to drive the positioning finger mounting frame and the floating positioning fingers to move centripetally.

Preferably, the number of the driving springs is 2, one end of each driving spring is fixed to the hook plate, and the other end of each driving spring is fixed to the front end of the positioning finger installation frame.

Preferably, the supporting device comprises a supporting claw, a connecting plate and a positioning groove plate, the supporting claw is fixedly connected to the outer side of the connecting plate, and the positioning groove plate is fixedly connected to the inner side of the connecting plate and adjacent to the pulling plate.

Preferably, the positioning groove plate is a concave groove plate with an upward opening, the lower surface of the hook plate is a hook part protruding downwards, the hook part can move in the concave groove plate, when the hook plate moves centripetally to contact the rear side surface of the concave groove plate, the connecting plate is driven to move centripetally, and when the lug boss at the end part of the lifting claw moves to the position below the wafer, the stepping motor stops rotating.

Preferably, the positioning finger mounting frame, the connecting plate and the pulling plate are arranged on the bottom plate through linear guide rails.

Preferably, the floating positioning finger comprises a positioning finger seat, a core shaft and a guide pillar, the guide pillar is arranged at the bottom end of the core shaft, and a boss is arranged on the guide pillar.

Preferably, a return spring sleeved on the periphery of the mandrel is arranged between the positioning finger seat and the boss, the whole step-by-step wafer positioning and supporting device moves downwards, and when the guide pillar contacts the platform, the return spring is compressed.

Has the beneficial effects that: compared with the prior art, the invention has the following advantages:

(1) The invention is positioned firstly and then supported when in clamping. During placement, the wafer slides down along the floating positioning fingers first and then is released. The positioning, the pushing and the placing of the wafer are completed in two steps, so that the accurate clamping and placing of the wafer can be realized.

(2) The floating positioning fingers are connected with the connecting frame in a floating mode, so that the floating positioning fingers can firstly contact the placing platform, the stroke of the free falling body of the wafer is greatly reduced, the placing deviation is reduced, the impact force of contact of the device is relieved, and the wafer is prevented from being damaged. And the reset spring is used for resetting, so that the wafer can be close to the placing platform as much as possible when descending, and the deviation caused by placing the wafer is prevented.

(3) Three stepping motors are adopted to simultaneously operate the positioning and lifting devices arranged at 120 degrees, so that high synchronism and positioning accuracy can be ensured.

Drawings

FIG. 1 is a schematic diagram of an overall structure of a step-by-step wafer positioning and lifting apparatus;

FIG. 2 is a schematic diagram of a portion of a step-by-step wafer positioning and lifting apparatus;

FIG. 3 is a schematic view of the structure of the lifting device of the present invention;

FIG. 4 is a schematic diagram of a floating positioning finger of the step-by-step wafer positioning and lifting apparatus;

FIG. 5 is a cross-sectional view of the floating fingers of the step-down wafer positioning and lifting apparatus.

Detailed Description

The present invention will be further illustrated by the following specific examples, which are carried out on the premise of the technical scheme of the present invention, and it should be understood that these examples are only for illustrating the present invention and are not intended to limit the scope of the present invention.

As shown in fig. 1, a step-by-step wafer positioning and supporting device includes a driving device, a supporting device and a positioning device uniformly distributed on a bottom plate 12, the driving device, the supporting device and the positioning device of this embodiment are provided with 3 sets, the driving device, the supporting device and the positioning device are uniformly arranged on a circumference at intervals of 120 degrees, the positioning device realizes accurate positioning of a wafer, and the supporting device realizes supporting and putting down of the wafer. The driving device is simultaneously connected with the supporting device and the positioning device, and drives the supporting device and the positioning device to act, so that the positioning, the lifting and the putting down of the wafer are realized. The stepping motor 1 moves forward to drive the floating positioning finger 4 to move inwards along the radial direction of the wafer, so that the centering of the wafer is realized, the stepping motor 1 continuously moves forward, the pulling plate 2 drives the lifting device to move centripetally, and the lifting device lifts the wafer after being tightened.

As shown in fig. 2, taking one of the driving device, the lifting device and the positioning device as an example for detailed description, the driving device includes a stepping motor 1 and a pulling plate 2, the stepping motor 1 is connected with the pulling plate 2 through a screw rod 5, a linear guide rail 11 is disposed below the pulling plate 2, and the stepping motor 1 drives the pulling plate 2 to slide along the linear guide rail 11 in a reciprocating manner.

Positioner indicates mounting bracket 3 and unsteady location to indicate 4 including the location, and step motor 1 is connected through lead screw 5 to 2 one ends of arm-tie, and the other end indicates mounting bracket 3 to connect unsteady location to indicate 4 through the location, and 2 unsteady connections of arm-tie hold up the device simultaneously, and the location indicates that 3 ends of mounting bracket are provided with one and float location to indicate 4, perhaps fixes a position and indicates that 3 ends of mounting bracket are parallelly connected and set up two and float location to indicate 4, hold up the device and be located two and float between the location and indicate 4. The locating finger mounting rack 3 is connected with the bottom plate 12 through the linear guide rail 11, and the linear guide rails below the locating finger mounting rack 3 are symmetrically provided with 2 groups which respectively correspond to the positions of 2 floating locating fingers 4.

The outside of arm-tie 2 is hook plate 6, and hook plate 6 is connected with location finger mounting bracket 3 through drive spring 7, and during arm-tie 2 centripetal movement, drive spring 7 was stretched, drives location finger mounting bracket 3 and the centripetal movement of floating location finger 4. In this embodiment, 2 driving springs 7 are provided, one end of each driving spring 7 is fixed on the hook plate 6, and the other end of each driving spring is fixed at the front end of the finger positioning mounting frame 3. The angle between the individual drive springs 7 is approximately 50-70 deg., where an angle of 60 deg. is chosen, taking into account the spring position and the pulling force.

The location indicates that mounting bracket 3 both sides still are provided with auxiliary frame 31, the location indicates that mounting bracket 3 and auxiliary frame 31 form U type structure, respectively be provided with auxiliary spring 32 in the below of two auxiliary frames 31, auxiliary spring 32 one end (the one end that is close to the wafer periphery) is fixed on bottom plate 12, the lower terminal surface at auxiliary frame 31 is fixed to the other end (the one end that is close to the wafer centre of a circle), the auxiliary spring 32 symmetry of both sides sets up, the pulling force is the same, auxiliary frame 31 does benefit to whole location and indicates the processing and the structural stability of mounting bracket 3, two auxiliary spring 32 can assist whole location and indicate that mounting bracket 3 resets, make the unsteady location indicate 4 and lift claw 8 get back to the wafer and get back to the initial position before getting.

In this embodiment, the floating positioning fingers 4 are arranged in 3 groups or 6 groups, and are uniformly spaced on the outer circumference. Every 3 ends of locating finger mounting bracket can be provided with one and float locating finger 4, and three floating locating finger 4 forms three point location, in order to prevent that 3 float locating fingers have more than one recess of embedding wafer 2 in, influence the location, preferably, 3 ends of locating finger mounting bracket can parallelly connected set up two floating locating fingers 4, form 6 point locations, and the location is more accurate, prevents that partial floating locating finger from imbedding in the ditch inslot of the self of wafer. Taking a 300mm diameter wafer as an example, the wafer itself has a tolerance range of 150 μm, and there is a 1-2mm deviation in wafer placement. The three groups of positioning components move simultaneously, and the high-precision stepping motor 1 drives simultaneously, so that the device can adapt to errors of wafers and position deviation in placement.

The floating positioning finger 4 comprises a positioning finger seat 41, a core shaft 42 and a guide post 43, wherein a ball bush assembly 44 is arranged at the upper end part in the core shaft 42, the core shaft 42 is movably arranged in the ball bush assembly 44, the guide post 43 is arranged at the bottom end of the core shaft 42, and a boss 46 is arranged on the guide post 43. A return spring 45 sleeved on the periphery of the mandrel 42 is arranged between the positioning finger seat 41 and the boss 46, the whole step-by-step wafer positioning and supporting device moves downwards, and when the guide pillar 43 contacts the platform, the return spring 45 is compressed.

As shown in fig. 3, the lifting device includes a lifting claw 8, a connecting plate 9 and a positioning groove plate 10, the lifting claw 8 is fixedly connected to the outer side of the connecting plate 9, and the positioning groove plate 10 is fixedly connected to the inner side of the connecting plate 9 and adjacent to the pulling plate 2. The positioning groove plate 10 is a concave groove plate with an upward opening, the lower surface of the hook plate 6 is a hook part 61 protruding downwards, the hook part 61 can move in the concave groove plate, after the hook plate 6 moves in a centripetal mode to contact with the inner rear surface of the concave groove plate (the inner rear surface is defined as one side close to the center of a circle of a wafer), the connecting plate 9 is driven to move in a centripetal mode, and when a boss at the end part of the lifting claw 8 moves to the position below the wafer, the stepping motor 1 stops rotating.

The lifting claw 8 is made of plastic, the thickness of the tip end is 1.5mm, and the lifting claw 8 extends into the lower part of the wafer to lift the wafer 2. The lifting claw 8 is provided with an adjusting screw 13 which can adjust the distance between the lifting claw 8 and the connecting plate 9.

All moving parts are arranged in a protective cover (not shown in the figure) made of PC polycarbonate or stainless steel materials, the moving parts comprise movable parts of a supporting device and a positioning device, and a vacuum dust suction pipeline is arranged above the protective cover and sucks away dust particles abraded or falling off by the moving parts so as to prevent the wafers from being polluted.

The working principle and the steps of the invention are as follows:

1. the step type wafer positioning and lifting device is used for clamping and lifting the wafer separately:

(1) When the wafer is clamped, the step-by-step wafer positioning and supporting device is driven by the moving shaft of the machine tool to move downwards to be close to the wafer.

(2) After the preset height is reached, the three stepping motors 1 synchronously rotate, the pull plate 2 is driven to move towards the center through the lead screw 5, meanwhile, the driving spring 7 is stretched, the 3 positioning finger mounting frames 3 are driven to move towards the center direction of the wafer, and the 6 floating positioning fingers 4 are in contact with the wafer, so that the self-centering effect on the wafer is achieved, and the circle center positioning of the wafer is completed.

(3) The pulling plate 2 continues to move centripetally, and when the pulling plate contacts with the inner rear surface (the inner rear surface is defined as the side close to the center of the wafer) of the limiting groove 10, the pulling plate simultaneously drives the three connecting plates 9 and the three lifting claws 8 to move centripetally together.

(4) When the bosses at the end parts of the three lifting claws 8 move to the positions below the wafer, the stepping motor 1 stops rotating, and the moving shaft of the machine tool drives the stepping wafer to position, lift and load and lift the wafer together to finish clamping the wafer.

2. The step-by-step wafer positioning and supporting device is used for accurately placing the wafer and is also carried out in two steps:

(1) The machine tool movement shaft drives the step-by-step wafer positioning and supporting device and the wafer to approach the placing platform.

(2) When the wafer approaches the placing platform, the guide posts 43 of the floating positioning fingers 4 are first contacted with the placing platform because they protrude from the lower surface of the wafer.

(3) The step-by-step wafer positioning and lifting device continues to move downward and the return springs 45 between the floating positioning fingers 4 are compressed. Since the floating fingers 4 are tensioned by the spring force of the return spring 45, the friction force on the wafer is not enough to overcome the gravity of the wafer, and the wafer slides down along the cylindrical surface of the guide posts 43 of the floating fingers 4 to approach the placing platform.

(4) When the bottom surface of the lifting claw 8 is close to the placing platform, the step type wafer positioning and lifting device stops descending, and the wafer is close to the placing platform.

(5) The stepping motor 1 rotates reversely, the lead screw 5 drives the pulling plate 2 to move outwards along the radius direction of the wafer, when the hook plate 6 of the pulling plate 2 contacts the front surface of the inner side of the limiting groove 10 (the front surface of the inner side is defined as one side close to the periphery of the wafer), the lifting claw 8 is pushed out, and the wafer slides to the surface of the placing platform along the floating positioning finger 4 under the action of gravity, so that accurate positioning and placing are completed.

(6) The stepper motor 1 continues to rotate in the reverse direction, the drive spring 7 relaxes and the floating fingers 4 move out of contact with the wafer.

(7) The step-by-step wafer positioning and supporting device is driven by a machine tool moving shaft to move upwards to complete the placing process.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that it is obvious to those skilled in the art that various modifications and improvements can be made without departing from the principle of the present invention, and these modifications and improvements should also be considered as the protection scope of the present invention.

Claims

1. The utility model provides a step by step wafer location and hold up device which characterized in that: the wafer centering device comprises a driving device, a supporting device and a positioning device which are uniformly distributed on a bottom plate (12), wherein the driving device comprises a stepping motor (1) and a pulling plate (2), the positioning device comprises a positioning finger mounting frame (3) and a floating positioning finger (4), one end of the pulling plate (2) is connected with the stepping motor (1), the other end of the pulling plate is connected with the floating positioning finger (4) through the positioning finger mounting frame (3), the pulling plate (2) is connected with the supporting device in a floating mode, the stepping motor (1) moves in the forward direction to drive the floating positioning finger (4) to move inwards in the radial direction of a wafer, the centering of the wafer is realized, the stepping motor (1) continuously moves in the forward direction, the pulling plate (2) drives the supporting device to move inwards, and the supporting device supports the wafer after being tightened; the driving device, the supporting device and the positioning device are at least provided with 3 groups, the driving device, the supporting device and the positioning device are uniformly arranged on the circumference at intervals, the tail end of the positioning finger mounting rack (3) is provided with one floating positioning finger (4), or the tail end of the positioning finger mounting rack (3) is provided with two floating positioning fingers (4) in parallel, and the supporting device is arranged between the two floating positioning fingers (4); the stepping motor (1) is connected with the pulling plate (2) through a screw rod (5); the outer side of the pulling plate (2) is provided with a hook plate (6), the hook plate (6) is connected with the positioning finger mounting frame (3) through a driving spring (7), and when the pulling plate (2) moves centripetally, the driving spring (7) is stretched to drive the positioning finger mounting frame (3) and the floating positioning fingers (4) to move centripetally;

the lifting device comprises a lifting claw (8), a connecting plate (9) and a positioning groove plate (10), the lifting claw (8) is fixedly connected to the outer side of the connecting plate (9), and the positioning groove plate (10) is fixedly connected to the inner side of the connecting plate (9) and is adjacent to the pulling plate (2); the positioning groove plate (10) is a concave groove plate with an upward opening, the lower surface of the hook plate (6) is provided with a hook part (61) protruding downwards, the hook part (61) can move in the concave groove plate, when the hook plate (6) moves centripetally to contact the rear side surface of the concave groove plate, the connecting plate (9) is driven to move centripetally, and when a boss at the end part of the lifting claw (8) moves to the position below a wafer, the stepping motor (1) stops rotating; the positioning finger mounting frame (3), the connecting plate (9) and the pulling plate (2) are all arranged on the bottom plate (12) through the linear guide rail (11).

2. The step-by-step wafer positioning and lifting device of claim 1, wherein: the number of the driving springs (7) is 2, one end of each driving spring (7) is fixed to the hook plate (6), and the other end of each driving spring is fixed to the front end of the positioning finger mounting frame (3).

3. The step-by-step wafer positioning and lifting device of claim 1, wherein: the floating positioning finger (4) comprises a positioning finger seat (41), a core shaft (42) and a guide post (43), wherein the guide post (43) is arranged at the bottom end of the core shaft (42), and a boss (46) is arranged on the guide post (43).

4. The step-by-step wafer positioning and lifting device of claim 3, wherein: a return spring (45) sleeved on the periphery of the mandrel (42) is arranged between the positioning finger seat (41) and the boss (46), the whole step-by-step wafer positioning and supporting device moves downwards, and when the guide pillar (43) contacts the platform, the return spring (45) is compressed.