JPH10249716A - Wafer polishing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polishing device in simplified installation by using a frictional type of power transmission instead of a gear. SOLUTION: For a polishing device, an internal gear 30 and an sun gear 40 are provided to be engaged with a gear formed on the outer periphery of a carrier 65, in which a wafer is stored, so that the carrier 65 can be held between a lower surface plate 20 and an upper surface plate 50. Driving pulleys 23, 33 put in frictional contact with the respective power transmission parts 35, 45, 25, 55 of the internal gear 30, the sun gear 40, the lower surface plate 20 and the upper surface plate 50 are used to rotate the internal gear 30, the sun gear 40, the lower surface plate 20 and the upper surface plate 50. The driving pulleys 23, 33 can be even fixed directly to the output shaft of a driving motor, not via reduction gear 22, 32. If V-grooves are formed in the power transmission parts 25, 35 and the driving pulleys 23, 33 with the side faces shaped to be fitted into the V-grooves are used, frictional power transmission can be efficiently performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wafer polishing apparatus for lapping or polishing silicon wafers, compound semiconductor wafers and the like.

[0002]

2. Description of the Related Art In a polishing apparatus for performing processing such as lapping and polishing on a wafer, the wafer is processed while revolving and rotating a carrier containing the wafer between a lower surface plate and an upper surface plate. The carrier is provided with a plurality of workpiece input holes, each of which has a tooth portion formed on an outer periphery and accommodates a wafer. The carrier is engaged with the sun gear and the internal gear, placed on the lower platen at substantially equal intervals, the wafer is fitted into the work input hole, the upper platen is lowered, and the wafer is held between the lower platen. During processing, the upper platen, lower platen, sun gear,
Rotate each internal gear. The wafer is
Both surfaces are polished while revolving and rotating. After the processing, the upper platen is raised, and the wafer is taken out from the work input hole of the carrier.

In accordance with the tendency that the demand for wafers increases with the spread of semiconductor devices, various improvements to this type of polishing apparatus have been proposed. For example, Japanese Patent Laid-Open No. 5-2
In Japanese Patent No. 12670, by positioning the carrier with respect to the upper platen, the upper platen is raised, and then the carrier is positioned with respect to the apparatus main body, thereby enabling accurate positioning, and handling the processed wafer. Have proposed to automate it. Also, JP-A-8-22978
In Japanese Patent Application Publication No. 4 (1999), an upper platen and a lower platen on which a polishing pad is attached while holding the wafer on both the front and back surfaces of the polishing plate while holding the wafer between the upper platen and the lower platen and rotating and rotating the polishing plate. It is proposed that each be rotated.

[0004]

In any of the polishing apparatuses, since the upper and lower stools, the sun gear and the internal gear are independently rotated, the power transmission and reduction mechanisms are complicated. Moreover, in the conventional polishing apparatus, since gears are used for the power transmission and the reduction mechanism, a large number of parts machined with high precision are required for each rotating element. As a result, the cost of the entire apparatus increases. In particular, in recent years, in which the diameter of the wafer tends to increase, the size of each component also increases, and the demand for processing accuracy becomes extremely severe. In addition, since power is transmitted using gears, generation of vibrations is inevitable, and the working environment may be deteriorated due to noise, and may adversely affect the wafer being processed. The present invention has been devised to solve such a problem. By using a frictional force or a timing belt for a power transmission mechanism instead of a gear, the structure is simplified and the size of the apparatus is increased. It is an object of the present invention to provide a polishing apparatus that can sufficiently cope with the above and that generates less vibration.

[0005]

In order to achieve the object, a wafer polishing apparatus according to the present invention has a carrier for accommodating a wafer and a gear meshing with a gear portion formed on the outer periphery of the carrier formed on the inner peripheral surface. Internal gear, a sun gear in which a gear meshing with a gear portion formed on the outer periphery of the carrier is engraved on the outer peripheral surface, a lower surface plate on which the carrier is mounted, and an upper surface plate for holding the carrier between the lower surface plate And a drive pulley that frictionally contacts the power transmission unit of each of the internal gear, sun gear, lower platen and upper platen, and a drive motor that rotates the drive pulley, and driven by frictional contact between the drive pulley and the power transmission unit The power from the motor is transmitted to the internal gear, sun gear, lower platen and upper platen. The drive pulley can be directly fixed to the output shaft of the drive motor without using a reduction gear. When a V-groove is formed in the power transmission portion and a drive pulley having a side surface shape that fits into the V-groove is used, power transmission by friction is performed efficiently. When transmitting large power,
A cocked belt may be fixed to the power transmission unit.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 1, a polishing apparatus according to the present invention comprises a bed 10, a motor 21 for driving a lower platen 20, a motor 31 for driving an internal gear 30, and a sun gear 40.
A driving motor (not shown) and a motor (not shown) for driving the upper stool 50 are mounted. A column 11 is erected on the bed 10, and a beam 12 extends between the left and right columns 11, 11. A lifting cylinder 13 provided on the beam 12 is connected to a lifting disk 14,
A hanging rod 16 having an upper surface plate hanging tool 15 at a lower end is fixed to the lifting disk 14. The power from the motor 21 is transmitted to the drive pulley 23 via the speed reducer 22. The drive pulley 23 is in frictional contact with the power transmission unit 25 of the lower stool receiver 24. Thus, the lower stool 20 on the lower stool support 24 is rotated by the power from the motor 21.

[0007] The power from the motor 31 is transmitted to the drive pulley 33 via the speed reducer 32. The drive pulley 33 is
It is in frictional contact with the power transmission section 35 of the internal gear 30. As a result, the internal gear 30
It rotates with power from one. The sun gear 40 also rotates with power transmitted to the power transmission unit 45 from a dedicated motor (not shown) via a drive pulley (not shown). Upper surface plate 50
Is opened in a circular shape, and the upper surface plate drive shaft 54 faces the opening from below. Upper surface plate drive shaft 5
The lower end of 4 is a power transmission section 55, from which power is transmitted from a dedicated motor (not shown) via a drive pulley (not shown). At the upper end of the upper platen drive shaft 54, two notches 56, 56 are formed at axially symmetric positions as shown in FIG. A hook 58 pivotally supported by a hook base 57 fixed to the upper surface plate 50 fits into the notch 56.
The upper platen 50 integrated with the upper platen drive shaft 54 by engaging the hook 58 with the notch 56 transmits power from a dedicated motor (not shown) via a drive pulley (not shown). It rotates with the power transmitted to the unit 55.

[0008] A gear portion 66 is formed on the outer periphery of the carrier 65 that accommodates the wafer 60 to be processed. The gear portion 66 meshes with the internal gear 30 and the sun gear 40, and the plurality of carriers 65 are arranged at substantially equal intervals on the lower surface plate 20.
And sandwiched between the upper platen 50. When the lower platen 20, the upper platen 50, the internal gear 30, and the sun gear 40 are independently rotated while supplying the abrasive in this state, a large number of wafers 65 are simultaneously polished. In this polishing apparatus, a frictional force is used instead of a conventional gear as a power transmission means from the driving pulleys 23, 33,... To the power transmission units 25, 35, 45, 55.

For example, the power transmission to the lower platen 20 will be described by way of example. As shown in FIG. 3, a drive pulley 23 connected to a lower platen driving motor 21 is pressed against a power transmitting portion 25 of a lower platen support 24 to generate friction. The power of the motor 21 is transmitted to the lower stool 20 by force. In the power transmission system using frictional force, the motor 21 directly rotates the lower platen 20, so that the expensive reducer 22 can be omitted, and the degree of freedom in designing around the motor 21 is increased. Further, the necessary driving force can be secured by increasing the number of motors 21. In order to smoothly transmit power by friction, the drive pulley 23 and the power transmission unit 25 are selected from rubber-based or metal-based materials such as butadiene, styrene, isobutylene, nitrile butadiene, silicon, and urethane having a large friction coefficient. . In the metal power transmission unit 25, small irregularities may be provided on the outer cylinder surface so that a large driving force is transmitted. FIG. 4 is an enlarged view of part A of FIG.
As shown in FIG.
Of the motor 21 is transmitted to the lower platen 20 by friction between the two.

When transmitting a large driving force, FIG.
As shown in (1), one or more V-grooves are formed on the side surface of the power transmission unit 25, and a driving pulley 23 having a side surface shape fitted into the V-groove is used. Alternatively, as shown in FIG. 4C, a cocked belt 26 made of an elastic material such as rubber is fixed to the peripheral surface of the power transmission unit 25 by bonding, screwing, or the like, and similarly fixed to the drive pulley 23 side. Cocked belt (not shown)
And transmit power. In this case, a metal gear having a small diameter and low cost can be used for the drive pulley 23 side. Thus, each motor 21, 3
Since power is transmitted to the lower platen 20, the internal gear 30, the sun gear 40, and the upper platen 50 by friction from 1..., Noise is smaller than that of a conventional polishing device, and the equipment configuration is greatly simplified. You. Since the lower platen 20, the internal gear 30, the sun gear 40, and the upper platen 50 can be directly rotated by the motors 21, 31,... Without using a reduction gear, a large driving force is required. Even in this case, the required driving force can be obtained by arranging a plurality of inexpensive small motors without using a large motor. In the above example, for example, the rotational power is transmitted from the power transmission unit 25 to the lower surface plate receiver 24. However, the power transmission unit 25 may be omitted, and the outer peripheral surface and / or the inner peripheral surface of the lower stool support 24 may be directly driven by a similar method. By omitting the power transmission unit 25, the structure inside the bed 10 is further simplified, and the degree of freedom in design is improved.

[0011]

As described above, the polishing apparatus of the present invention transmits power by frictional force instead of the conventional gear, so that the equipment configuration is simplified and the apparatus has low noise.
In addition, since high-precision processing is required, a costly gear is not required, so that the cost of the equipment itself is reduced.
Moreover, since power transmission without the reduction gear is possible,
By arranging a plurality of inexpensive motors in place of expensive large motors, necessary large power can be transmitted to the lower stool, the upper stool, and the like.

[Brief description of the drawings]

FIG. 1 shows a polishing apparatus according to the present invention.

FIG. 2 A lower platen on which a carrier containing a wafer is placed

Fig. 3 Power transmission when lower platen is directly rotated by motor

FIG. 4 shows several examples of a contact state between a driving pulley and a power transmission unit.

[Explanation of symbols]

10: Bed 11: Column 12: Beam 1
3: Lifting cylinder 14: Lifting disk 15: Upper surface plate hanging tool 16: Hanging rod 20: Lower surface plate 21: Lower surface plate driving motor 22:
Reduction gear 23: Drive pulley 24: Lower surface plate receiver
25: Power transmission unit 26: Cocked belt 30: Internal gear 31: Internal gear drive motor 32: Reduction gear 33: Drive pulley
35: Power transmission unit 40: Sun gear 45: Power transmission unit 50: Upper surface plate 54: Upper surface plate drive shaft 55: Power transmission unit 56: Notch 57: Hook base 58: Hook 60: Wafer 65: Carrier 66: Gear Department

Claims (4)

[Claims] 1. A carrier accommodating a wafer, an internal gear in which a gear meshing with a gear portion formed on the outer periphery of the carrier is engraved on an inner peripheral surface, and a gear meshing with a gear portion formed on the outer periphery of the carrier. The sun gear engraved on the outer peripheral surface, the lower stool that mounts the carrier, the upper stool that holds the carrier between the lower stool, and the power transmission parts of the internal gear, sun gear, lower stool, and the upper stool A drive pulley that makes frictional contact and a drive motor that rotates the drive pulley are provided. The power from the drive motor is applied to the internal gear, sun gear, lower platen, and upper platen by frictional contact between the drive pulley and the power transmission unit. Wafer polishing equipment to be transmitted. 2. The wafer polishing apparatus according to claim 1, wherein a driving pulley is fixed to an output shaft of the driving motor. 3. The wafer polishing apparatus according to claim 1, wherein a V-groove is formed in the power transmission portion, and the drive pulley has a side surface shape that fits into the V-groove. 4. The wafer polishing apparatus according to claim 1, wherein a cocked belt is fixed to the power transmission unit.