JPH05261661A - Work feed and recovery method in lapping unit - Google Patents

Abstract

PURPOSE:To provide a work feed-recovery method in a lapping unit that has automated the feed or recovery to or from a carrier. CONSTITUTION:In a lapping unit provided with a carrier, a sun gear 5, an internal gear 6 and a lower surface plate 2 are intermittently rotated each synchronously in the same sense with equal angles and equal turning angles, and each carrier is shifted to a constant position successively and stopped. At the time of this rotation, the carrier is detected at a position before the carrier reaches the constant position, and each rotational speed of those of sun gear, internal gear and lower surface plate is reduced to sane extent, and at a time when the carrier reaches the constant position, the carrier is detected, stopping each rotation of those of sun gear, internal gear and lower surface plate, thus a work is fed or recovered to or from the carrier stopped at a constant position.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of supplying a work piece to a carrier and collecting the work piece from the carrier in a lapping machine.

[0002]

2. Description of the Related Art Lapping apparatuses are widely used for grinding such as when grinding the surface of a semiconductor wafer or a substrate used for a hard disk.

This lapping device is arranged between an upper surface plate and a lower surface plate, a sun gear, an internal gear that concentrically surrounds the sun gear, and a space between the sun gear and the internal gear and meshes with these gears. It is equipped with a plurality of carriers, and the work is held on this carrier to rotate and revolve the carrier by the rotation of the sun gear and internal gear, and the upper surface plate and the lower surface plate rotate while pressing the workpiece. Then, the workpiece is ground.

[0004]

In this lapping apparatus, it is necessary to supply and hold the work piece to the carrier before performing the grinding work, and to remove the worked work piece from the carrier after the grinding work is completed and collect the work piece.

Conventionally, in a lapping apparatus, an operator manually supplies and collects a workpiece to and from a carrier. That is, the driving of the lapping device is stopped, the worker goes around the lapping device, and collects the ground workpieces held by each carrier,
Instead, it supplies each carrier with the work to be processed.

Therefore, it takes a lot of trouble to collect and supply the work pieces, which may cause a long time for the grinding process.

As a countermeasure against this, it is desired to automatically supply and recover the workpieces by a machine without human intervention. However, in this case, there is a risk of damaging the ground workpiece, and it is necessary to accurately stop the plurality of carriers at a predetermined position. Therefore, these points had to be solved in order to automate the supply and recovery of the workpieces.

The present invention has been made in view of the above circumstances, and it is possible to accurately stop a plurality of carriers at a predetermined position sequentially without damaging the ground work, and to supply the work to the carrier. An object of the present invention is to provide a work supply / recovery method in a lapping device in which recovery is automated.

[0009]

In order to achieve the above-mentioned object, a method of supplying and recovering a work in a lapping apparatus of the present invention comprises a sun gear between an upper surface plate and a lower surface plate, and an internal member concentrically surrounding the sun gear. A lapping device provided with a gear, a plurality of carriers arranged between the sun gear and the internal gear and meshing with the respective gears and holding a workpiece, wherein the sun gear, the internal gear and the lower platen are provided. Are intermittently rotated synchronously with the same direction, the same angular velocity and the same rotation angle, and each carrier is sequentially moved to a fixed position and stopped, and at the time of this movement, before the carrier reaches the fixed position. Detecting the carrier at the position of to reduce the rotation speed of the sun gear, the internal gear and the lower platen, When the carrier reaches a fixed position, the carrier is detected to stop the rotation of the sun gear, the internal gear, and the lower platen, and the workpiece is collected for the stopped carrier, and It is characterized by supplying goods.

[0010]

[Function] The sun gear, the internal gear and the lower platen are synchronously and intermittently rotated. Therefore, it is possible to sequentially move and stop the plurality of carriers with respect to the position for supplying and collecting the workpiece.

When the carrier is intermittently moved, the sun gear, the internal gear and the lower platen are rotated at the same angular velocity. For this reason, carriers and workpieces are
It will be stationary with respect to the internal gear and lower surface plate, and the surface of the ground work will not be damaged by the lower surface plate.

When the carrier is moved intermittently, the carrier is detected at a position before the carrier reaches the position for supplying and recovering the workpiece to reduce the rotational speeds of the sun gear, the internal gear and the lower surface plate. When the carrier reaches a fixed position, the carrier is detected and the rotation of the sun gear, the internal gear, and the lower platen is stopped, so that the carrier can be stopped at the fixed position with reasonable accuracy.

[0013]

Embodiments of the present invention will be described with reference to the drawings.

The structure of the lapping apparatus to which this embodiment is directed will be described with reference to FIGS. 1 and 2.

In the figure, reference numeral 1 is an upper surface plate, and 2 is a lower surface plate disposed so as to face the upper surface plate 1. The upper surface plate 1 is supported by a lift cylinder (not shown), and a grindstone 3 is attached to the lower surface thereof. A grindstone 4 is attached to the upper surface of the lower surface plate 2.
The upper surface plate 1 is rotated by a servo motor (not shown), and the lower surface plate 2 is rotated by a servo motor as described later.

A sun gear 5 is arranged between the upper surface plate 1 and the lower surface plate 2 at the same position as the central axis of these surface plates 1, 2.
And an internal gear 6 that is concentrically arranged to surround the sun gear 5. Further, a plurality of, for example, five carriers 7 are arranged between the sun gear 5 and the internal gear 6 at equal intervals (angles of 72 degrees). Teeth formed on the outer peripheral portion of each carrier 7 are meshed with the sun gear 5 and the internal gear 6. A plurality of holding holes 8 are formed in each carrier 7, and a workpiece 9, for example, a semiconductor substrate is inserted and held in each of the holding holes 8. The workpieces 9 held in these holding holes 8 are the lower surface plate 2
It is placed on the upper surface of the whetstone 4. The sun gear 5 and the internal gear 6 are independently rotated by dedicated servo motors as described later.

Therefore, when grinding the workpiece 9, the upper surface plate 1 is lowered by the cylinder and the workpiece 9 is sandwiched by the grindstones 3 and 4. The upper surface plate 1 and the lower surface plate 2 are rotated by motors in directions A and B, respectively, and the sun gear 5 and the internal gear 6 are rotated by motors in direction B, respectively. As a result, the carrier 7 revolves in the B direction while rotating. As a result, the respective workpieces 9 held in the respective holding holes 8 of the respective carriers 7 are given the rotation of the upper surface plate 1, the rotation of the lower surface plate 2, and the respective motions of the rotation and the revolution of the carrier 7 and the upper surface. The lower surface and the lower surface are ground by the grindstones 3 and 4, respectively, and lapping eyes (striated eyes) are formed on these upper and lower surfaces.

When the grinding process is completed, the rotation speeds of the upper and lower surface plates 1 and 2 and the gears 5 and 6 are reduced, the carrier 7 is detected at a certain position, and the carrier 7 is moved a predetermined distance from the detected position. At this point, the movement of the carrier 7 is stopped.

Next, in this lapping apparatus, a method for collecting the machined workpiece 9 after the completion of grinding and supplying a new workpiece 9 will be described.

The feature of the method of the present invention is that the carrier 7 is intermittently moved with respect to a predetermined position, and when the carrier 7 is moved, the lower platen 2, the sun gear 5 and the internal gear 6 are rotated at an equal angular velocity, The lower platen 2, the sun gear 5, and the internal gear 6 should be in the same state as those stationary with respect to the carrier 7, and the carrier 7 should be divided into two stages before the carrier 7 stops at a predetermined position when the carrier 7 moves. Is detected, the carrier 7 is decelerated at the first stage, and the carrier 7 is stopped at the second stage. In FIG. 1, Z
Is a workpiece supply / recovery position.

A configuration for implementing the method of the present invention will be described.

The lapping device includes a first sensor 11
And a second sensor 12 is provided. These sensors 11 and 12 detect the position of the carrier 7A located on the rear side in the rotation direction (moving direction) with respect to the carrier 7A located at the workpiece supply / recovery position Z, and detect the position of the carrier 7A. Considered, that information is used to slow down and stop the carrier 7A. That is, the second sensor 12 is arranged at a position spaced by an angle of 72 degrees behind the workpiece supply / recovery position Z in the rotational direction (a position at which the rear carrier 7 stops when the carrier 7A stops). The first sensor 11 is arranged at a position spaced a predetermined distance behind the sensor 12 in the rotation direction. As shown in FIGS. 2 and 4, first and second sensors 1
Reference numerals 1 and 12 are reflection type photoelectric switches focusing on the teeth of the carrier 7, and the detection signals thereof are output to a controller 29 described later.

As shown in FIG. 4, the first sensor 1
When the light of No. 1 hits the teeth of the carrier 7 to detect the carrier 7, the light of the second sensor 12 deviates from the teeth of the carrier 7 and the carrier 7 cannot be detected. When the light hits the teeth of the carrier 7 to detect the carrier 7, the light of the first sensor 11 deviates from the teeth of the carrier 7 so that the carrier 7 cannot be detected.

A circuit for driving the lapping device when the carrier 7 is supplied and recovered will be described with reference to FIG.

Reference numeral 21 in the drawing denotes a rotation speed setting device, which is a motor 41 for rotating the lower surface plate 2 and a motor for rotating the sun gear 5.
Motor 43 for rotating the motor 42 and the internal gear 6
The reference voltage corresponding to the rotation speed of is set.
A lamp circuit 22 sets the rising and falling voltages of the motors 41 to 43 according to the reference voltage set by the rotation speed setting unit 21. 23, 24 and 25 are ratio setting devices corresponding to the motors 41, 42 and 43, respectively.
6, 27 and 28 are drive units corresponding to the respective motors 41, 42 and 43, and the drive units 26 to 28 are driven based on the reference voltage set by the ratio setters 23 to 25.
Drives the switches 41 to 43. Incidentally, 44, 45 and 46 detect the rotation speeds of the respective motors 41, 42 and 43 and output the detection information to the respective drive units 27 to 29. Each drive unit 26-28 receives this signal and controls the rotation speed of each motor 41, 42, 43.

The relays Ry1, Ry2, Ry3 are relays attached to the rotation speed setting device 21, and are provided in a number corresponding to the stepwise speed set by the rotation speed setting device 21, for example, three. The relays Ry4, Ry5, and Ry6 are each ratio setter 23.
25 to 25 and the drive units 26 to 28, respectively. A controller 29 drives each of the relays Ry1 to Ry3 and each of the relays Ry4 to Ry6. 30 is a controller 29
Is a start switch connected to. The controller 29 receives the detection information from the sensors 11 and 12.

Next, the operation of supplying and recovering the workpiece 9 at the end of the grinding process will be described.

The basic operation is as follows.

When the start switch 30 is closed, the controller 29 closes the relays Ry4 to Ry6. The rotation speed setting device 21 sets a reference voltage according to the rotation speed of each of the motors 41 to 43, and the ramp circuit 22 integrates the reference voltage and outputs it to each of the ratio setting devices 23 to 25. At this time, in the lamp circuit 22, the reference voltage is set in accordance with the rising and falling of the slowest following motor among the motors 41 to 43, specifically, the motor 41 for the lower surface plate 2. To do. Each ratio setter 23-25 sets a reference voltage based on a predetermined ratio and outputs it to each drive unit 26-28, and each drive unit 26-28 drives each motor 41-43. When the controller 29 opens the relays Ry4 to Ry6, the rotation of the motors 41 to 43 is stopped. In addition, each motor 41
~ 43 is a servo motor, each drive unit 26 ~ 2
When the signal from 8 is cut off, the brake is applied immediately and the rotation is stopped.

In this way, the lower turn table 2, the sun gear 5, and the internal gear 6 are rotated, whereby the carrier 7 is moved. In the method of the present invention, the following operation is performed in this basic operation.

First, each carrier 7 is sequentially moved to the workpiece supply / recovery position Z and stopped. That is, each carrier 7 is intermittently moved (revolved) at an angle of 72 degrees between the carriers 7. That is, the lower surface plate 2 and the sun gear 5 are arranged so that each carrier 7 moves intermittently in this way.
Also, the internal gear 6 is intermittently rotated. At the workpiece supply / recovery position Z, the machined workpiece 9 held in the holding hole 8 of each carrier 7 is removed, and a new workpiece is held in the holding hole 8 instead. This operation is performed by an automatic machine.

Then, when each carrier 7 is intermittently moved toward the workpiece supply / recovery position Z, the lower platen 2, the sun gear 5, and the internal gear 6 are directed in the direction B at the same angular velocity. To rotate. That is,
The ratio setters 23 to 25 set the reference voltages to the motors 41 to 42 based on a predetermined ratio so that the lower platen 2, the sun gear 5, and the internal gear 6 rotate in the B direction at the same angular velocity. Set. Carrier 7
Moves (revolves) in the same direction at the same angular velocity as the lower platen 2, the sun gear 5, and the internal gear 6. It does not rotate. As a result, the relationship between the workpiece 9, the carrier 7, the lower surface plate 2, the sun gear 5, and the internal gear 6 is the same as when stationary. That is, the lower surface plate 2 does not perform different movements with respect to the workpiece 9. Therefore, the lower surface of the ground workpiece 9 is not scraped by the lower surface plate 2 and the lapping eyes are not damaged.

Furthermore, when each carrier 7 is intermittently moved toward the workpiece supply / recovery position Z, the position of the carrier is detected using the two sensors 11 and 12, and the carrier 7 is stopped. After decelerating forward, it stops at the workpiece supply / recovery position Z. This action will be described.

The rotation speed setting device 21 sets the speed patterns of the lower platen 2, the sun gear 5, and the internal gear 6 while each carrier 7 rotates one section (angle 72 degrees) as shown in FIG. 5, for example. To do. That is, after rotating at 6 rpm, the speed is reduced in the order of 1 rpm and 0.3 rpm. The ramp circuit 22 sets the speed pattern shown in FIG. 6 based on the speed pattern set by the rotation speed setting device 21.

When moving the carrier 7, the controller 29 first closes the relay Ry1. As a result, the rotation speed setting device 21 outputs a command of speed 6 rpm to the ramp circuit 22, and the ramp circuit 22 sets the reference voltage based on this command. As a result, the lower platen 2, the sun gear 5, and the internal gear 6 are rotated at a speed of 6 rpm to rotate the carrier 7
Is moved in the B direction at a speed of 6 rpm.

Next, when the carrier 7 moves to the position of the first sensor 11, the first sensor 11 detects the carrier 7. The detection information of the first sensor 11 is the controller 29.
Is output to. The controller 29 receives the detection information from the first sensor 11 and closes the relay Ry2. Then, the rotation speed setting device 21 issues a command to the speed of 1 rpm. As a result, the lower turn table 2, the sun gear 5, and the internal gear 6 are rotated at a speed of 1 rpm to move the carrier 7 at a speed of 1 rpm. That is, the rotational speeds of the lower turn table 2, the sun gear 5, and the internal gear 6 are reduced, and thus the moving speed of the carrier 7 is reduced. At this time, the second sensor 12 does not detect the carrier 7.

Next, when the carrier 7 moves for a predetermined time, the controller 29 closes the relay Ry3. Then, the rotation speed setting device 21 issues a command for a speed of 0.3 rpm. As a result, the lower surface plate 2, the sun gear 5, and the internal gear 6
Is rotated at a speed of 0.3 rpm to move the carrier 7 to 0.3 r.
Move at a speed of pm. That is, the moving speeds of the lower surface plate 2, the sun gear 5, and the internal gear 6 are further reduced, and the moving speed of the carrier 7 is further reduced.

Next, when the carrier 7 moves to the position of the second sensor 12, the second sensor 11 detects the carrier 7. The detection information of the second sensor 12 is the controller 29.
Is output to. The controller 29 receives the detection information from the second sensor 12 and opens the relays Ry4 to Ry6. As a result, the rotation of each motor 41-43 is stopped, and the lower surface plate 2,
The movements of the sun gear 5 and the internal gear 6 also stop and the movement of the carrier 7 stops. That is, the carrier 7A located on the front side of the carrier 7 stops at the workpiece supply / recovery position Z.

Since the carrier 7 decelerates before reaching the workpiece supply / recovery position Z, the lower platen 2 and the sun gear 5 are decelerated.
Also, the carrier 7 of the internal gear 6 can be smoothly and accurately stopped at the workpiece supply / recovery position Z.

In this embodiment, the rotation speed setting device 21
Although three relays Ry1 to Ry3 were used as accessories attached to the above, at least two relays may be used.

In this embodiment, the sensors 11 and 12 detect the carrier 7 stopped at the front side of the workpiece supply / recovery position Z by the sensors 11 and 12, but the carrier 7 is detected at the workpiece supply / recovery position Z by the sensor 11. , 12 may be detected.

[0042]

As described above, according to the method of supplying and collecting the work in the lapping apparatus of the present invention, the plurality of carriers can be stopped accurately at a fixed position without damaging the work being ground. Therefore, it is possible to automate the supply and recovery of the work piece to the carrier.

[Brief description of drawings]

FIG. 1 is a plan view showing an example of a method of the present invention with an upper surface plate removed in a target lapping apparatus.

FIG. 2 is a sectional view showing a lapping device.

FIG. 3 is a block diagram showing a drive system of a lapping device.

FIG. 4 is a diagram showing a positional relationship between a sensor and a carrier.

FIG. 5 is a diagram showing a speed setting pattern in the speed setting device.

FIG. 6 is a diagram showing a speed setting pattern in a lamp circuit.

[Explanation of symbols]

1 ... Upper surface plate, 2 ... Lower surface plate, 5 ... Sun gear, 6 ... Inter gear, 7 ... Carrier, 9 ... Work piece, 21 ... Speed setting device,
22 ... Lamp circuit, 23-25 ... Ratio setting device, 26-2
8 ... Drive units, 41-43 ... Motors.

Claims (1)

[Claims] 1. A sun gear, which is provided between the upper surface plate and the lower surface plate,
In an internal gear that concentrically surrounds the sun gear, a lapping device that is provided between the sun gear and the internal gear, is provided with a plurality of carriers that mesh with these gears and hold a workpiece, The sun gear, the internal gear, and the lower platen are intermittently rotated synchronously with the same direction, the same angular velocity, and the same rotation angle, and the carriers are sequentially moved to a fixed position and stopped. At the time of movement, the carrier is detected at a position before the carrier reaches the fixed position to reduce the rotation speeds of the sun gear, the internal gear and the lower platen, and then the carrier reaches the fixed position. Sometimes the carrier is detected to stop and stop the rotation of the sun gear, the internal gear, and the lower platen. Workpiece supply and recovery method in lapping apparatus characterized by recovering supplying the workpiece and the workpiece relative to the carrier was.