JPH11277420A - Double surface polishing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the deposit and solidification of the slurry by forming a pin of a pin shaft and a collar fitted to the peripheral part of the pin shaft, providing the pin shaft with a groove in a surface thereof, and providing a lower end of the groove thereof with an open hole in the peripheral direction of the pin. SOLUTION: A work is pinched for pushing by an upper and a lower plates while always supplying the slurry including the abrasive granular powder, and a surface plate and the work are rotated for working. The slurry is evenly distributed over the whole of a polishing surface, and discharged. This slurry enters a narrow space between a pin shaft 10 and a collar 12. In this case, since the slurry entered inside of the pin structure is flowed downward along a groove 11a and discharged through an open hole 11b, hindrance of the smooth rotation of the collar 12 by the solidification and deposit of the slurry inside is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a processing machine for simultaneously processing both surfaces of a plate-like work requiring extremely high flatness and parallelism, and particularly to a structure for gripping the work. The present invention relates to an improvement in a device for driving a carrier for rotation.

[0002]

2. Description of the Related Art Conventionally, glass, metal materials, semiconductor materials,
Planar processing of plate-like workpieces that require particularly high flatness and parallelism with ceramics or carbon materials, etc.
A platen or a platen with a polishing pad attached is arranged on the top and bottom, and the work is sandwiched in the gap, and the platen and the work are pressed while the abrasive fine powder slurry as the abrasive is supplied quantitatively. There is a method in which the film is driven to rotate, and the thickness of the film is made uniform and the flatness and the parallelism are improved by the action. Specific examples include lapping or polishing, and grinding stone lapping using a synthetic whetstone placed on an upper and lower platen.

As shown in FIG. 1, these processing machines are provided with a surface plate having upper and lower surfaces facing each other, press and clamp a plate-like workpiece therebetween, and rotate the workpiece and / or the surface plate. And the slurry is quantitatively supplied to the working surface.
The upper and lower surfaces of the workpiece, which is the workpiece, are gradually and gradually removed by the action of the abrasive grains, and a surface having flat and precise surface roughness is created.

Here, the workpiece is pressed and clamped between an upper surface plate and a lower surface plate, each of which rotates differently, and at the same time, performs a so-called planetary motion of revolving while rotating itself. The processing proceeds by the combination of the frictional action and the action of the abrasive grains. In order to cause the work to cause this planetary motion, first, the work is fitted into a holding hole of a carrier for holding the work, and the carrier is rotated in that state. Teeth are formed on the outer periphery of the carrier, and the teeth are placed on a pin set on the sun wheel installed in the center of the surface plate and on an internal wheel installed along the outer edge of the surface plate It is designed to engage with the pin. By freely driving the internal wheel and the sun wheel, the carrier and the workpiece can freely perform planetary motion.

[0005] As described above, the carrier moves the workpiece differently from the upper and lower platens and processes the workpiece by the frictional force or the driving force generated during the movement. In addition, the teeth formed on the outer periphery must have little damage and wear, and in addition, the function cannot be fulfilled unless the workpiece has a shape thinner than the thickness of the workpiece. When using a silicon wafer or the like as a workpiece,
Since the surface area is large and the thickness is extremely thin, the material of the carrier is extremely limited. Specifically, metal materials such as SK steel and blue steel with excellent mechanical strength are used as materials for lapping applications, and epoxy resins, glass fiber reinforced epoxy resins, polycarbonate, SUS material or the like coated with Teflon is used as a material.

The so-called pin-drive type double-side polishing machine as described above is an internal-type polishing machine using a sun gear and an internal gear having a single structure made of hardened steel. Even if a pin portion of a car or a solar car is damaged, only the pin needs to be replaced, and by increasing the tooth ridge, there is an advantage that the relative mechanical strength is strong. Has begun to be used. During the processing operation of the double-sided processing machine, the teeth on the outer periphery of the carrier are driven by the pins set on the sun wheel and the internal wheel while the carrier is under high load, and are rotated and constantly in dynamic contact Although the contact surface is subject to high stress, this reciprocal movement is a mechanical engagement movement, and basically, unless there is a large play in the engagement between the tooth and the pin, Since there is no rubbing action between them, it is usual to use hardened steel or the like which is strong against mechanical stress and has little wear.

[0007] As an improvement of the pin drive type double-sided processing machine, a cylindrical pin is not fixed, but a rotatable roller. Reducing the resistance has been proposed in Japanese Patent Application Laid-Open No. 1-252356. In Japanese Patent Application Laid-Open No. 9-207063, for example, a resin sleeve is fitted around the outer periphery of a pin to obtain the same effect as a roller-shaped pin, and also to prevent metal contamination due to metallic fine powder generated by contact between the pin and a carrier. Is also disclosed.

[0008]

In the case of the above-mentioned system using a pin in which a sleeve (collar) is fitted on the outer periphery, the slurry containing fine abrasive grains used for processing enters the gap between the pin shaft and the collar, and therein. It is gradually concentrated and becomes a high-viscosity paste, which further solidifies to prevent the smooth rotation of the color and prevent its smooth rotation.The original purpose is not achieved. Especially when a resin color is used, the local damage of the color is remarkable. In order to prevent this, an operation such as periodically cleaning the pin portion was required. That is, this method was also difficult to be perfect.

The inventors of the present invention have conducted intensive studies on the above problems, and as a result, have considered the shape of the pin shaft in a pin drive type double-side polishing machine using a pin constituted by a pin shaft and a collar. By this, it was found that the above-mentioned color sticking can be suppressed, and the present invention has been completed.The purpose of the present invention is to prevent the accumulation and solidification of the slurry, and to make the color smooth at all times. It is an object of the present invention to provide a rotatable pin and its structure.

[0010]

SUMMARY OF THE INVENTION The object of the present invention is to hold a plate-like workpiece between two upper and lower facing plates while being fitted into a holding hole of a carrier, and to rotate under pressure to rotate both surfaces thereof. Wherein the teeth formed on the outer peripheral portion of the carrier are installed along the outer edge of the platen with a pin set on a sun wheel installed at the center of the platen. In a double-side polishing machine in which the carrier is driven to rotate by rotation of the sun wheel and the internal wheel, the pin fits on a pin shaft and an outer peripheral portion thereof. The pin shaft has a groove on the surface thereof, and the lower end of the groove has an open hole in the outer peripheral direction of the pin. Achieved by machine.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIGS. 1 and 2, a double-side polishing machine used in the method of the present invention comprises a disc-shaped upper platen 1 and a lower platen 2 which are rotatable on upper and lower opposing surfaces. A carrier 4 is arranged and performs planetary motion, an internal wheel 6 and a sun wheel 8 for driving the carrier 4. The workpiece 3 such as a wafer is set so as to fit into a holding hole of the carrier 4. In this method, the abrasive particles contained in the slurry act on the surface of the workpiece and are removed by the pressing force and the rotation of the platen. Its purpose is to correct uneven thickness of workpieces such as wafers,
An object of the present invention is to remove unevenness to provide excellent flatness and parallelism. Teeth 5 are carved on the outer periphery of the carrier 4, and the teeth 5 are equally spaced on an internal wheel 6 disposed on an outer peripheral portion of a surface plate of a processing machine and a sun wheel 8 disposed on an inner peripheral portion. The pins 7 and 9 are engaged with each other. By freely driving the internal wheel 6 and the solar wheel 8, the workpiece 3 and the carrier 4 can freely perform planetary motion.

FIG. 3 shows the structure of a pin in an embodiment of a double-side polishing machine according to the present invention. A in the figure
FIG. 1 is an exploded view of a pin that is divided into its constituent parts, and FIG. 1B is a view showing the appearance of the assembled pin. Pins 7 and 9 on internal car 6 and sun car 8
Are configured to accurately mesh with the teeth 5 arranged on the outer periphery of the carrier 4 as described above. As is clear from the figure,
The pin includes a pin shaft 10 fixed at the center thereof, a cylindrical collar 12 fitted to the pin shaft 10, and a cap 13 for preventing the collar 12 from falling off. Pin axis 1
Reference numeral 0 denotes a shaft portion 10a and a base portion 10b, and the collar 12 fitted to the shaft portion 10a is received by the edge-shaped base portion 10b. A band-shaped groove 11a is formed in the surface of the shaft portion 10a of the pin shaft 10 so as to be continuous with the base portion 10b, so that an open hole 11b opening to the outer peripheral portion of the pin is formed in the base portion 10b. And has no open end at the top of the groove. The shape of the groove may be a band-like shape as shown in FIG. 3 or a linear shape. Further, the groove may be linear from top to bottom, skewed, or meandering. Or a spiral shape, and is not particularly limited.

In the actual polishing operation, the workpiece is held and pressed by the upper and lower platens while the slurry containing abrasive fine powder is constantly supplied, and processing is performed while rotating the platen and the workpiece. Therefore, the slurry spreads evenly over the entire polishing surface and is discharged. The slurry also enters the narrow gap between the pin shaft 10 and the collar 12 at the same time. In this case, by using the pin having the structure of the present invention, the slurry that has entered the pin structure can be used as the groove 11.
a, it flows downward and is discharged to the outside through the open hole 11b, so that it accumulates and solidifies inside like a conventional pin,
It does not become stuck and hinder smooth rotation of the collar 12. Also, a small amount of film adhered to the inner surface of the collar is scraped off and discharged by the edge of the groove 11a, so that it does not accumulate and solidify. The groove 11a has a structure that does not have an open end at the upper part as shown in FIG. 3, so that the intrusion of slurry from the groove 11a can be prevented.

Examples of the shape of the groove 11a include a strip shape as shown in FIG. 3, a linear shape as shown in FIG. 4, and a spiral shape as shown in FIG. . By providing the groove 11a, the contact area between the collar 12 and the pin shaft 10 is reduced, and the friction coefficient is reduced, so that the rotation of the collar 12 becomes smoother. The total surface area of the groove is 10 to 90 with respect to the surface area of the pin shaft to which it fits.
% Is preferable. When the content is less than 10%, the slurry is not sufficiently discharged, and the deposition and solidification of the slurry occur to some extent, so that the color sticking is relatively likely to occur. Conversely, when the content exceeds 90%, the structure is slightly weaker. The pin shaft itself is slightly worn.

The material of the pin shaft 10 is not particularly limited, but it is preferable to use a hardened steel having excellent mechanical strength and excellent impact resistance, for example, SK4 steel or SK5 steel. Ceramics can also be used. Further, the material of the collar is not particularly limited, but metal, ceramics, resin, metal coated with resin or ceramic, or the like can be used. The outer diameter of the shaft portion 10a of the pin shaft 10 and the inner diameter of the collar 12 are approximated within a range in which the collar 12 can rotate, and a gap is hardly formed between them. By adopting such a shape, in an actual use, when an unsteady excessive force or stress is applied between the carrier 4 and the pins 7 and 9, the collar is rotated to cause the abnormal rotation. In addition to dispersing the forces, the relative position of the pins 7, 9
It is also possible to avoid local contact of the carrier teeth with certain parts of the car and to prevent local wear, for example, horizontal linear wear scars.

The pin shafts 10 are vertically and vertically fixed on the circumference of the sun wheel 8 or the internal wheel 6 at equal intervals so as to accurately mesh with the outer peripheral teeth 6 of the carrier 4. The method is not particularly limited. However, from the viewpoint of maintenance management of the machine base, it is better to make it detachable by means such as screwing. The collar 12 is fitted so as to cover the pin shaft 10, and the head is suppressed by the cap 13, so that the collar 12 is prevented from easily falling off or jumping out. The method of fixing the cap 13 is not particularly limited, but if the cap 13 is fixed to the pin shaft 10 by, for example, screwing, the collar can be easily attached and detached, which is advantageous.

[0017]

As described above, when the double-sided processing machine according to the present invention is used, the slurry that has entered the narrow gap between the collar and the pin shaft can be discharged very smoothly, and the color of the collar due to the solidification of the slurry is reduced. The occurrence of undesired phenomena such as sticking can be prevented in advance, thereby increasing the frequency of replacement of pins and carriers, further reducing the occurrence of metallic fine powder from pins and carriers, which has been regarded as a problem in the past, and The life of the carrier has been improved several times as compared with the conventional one, and the frequency of replacing the collar itself can be extended from one year to two years. That is, the effect of the present invention is extremely remarkable.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a main part of an apparatus.

FIG. 2 is a plan view of a main part of the device.

FIG. 3 is an assembly view showing the structure of a pin and the shape of a pin shaft.

FIG. 4 is a diagram showing another shape of the pin shaft.

FIG. 5 is a view showing still another structure of the pin shaft.

[Explanation of symbols]

1 Upper surface plate 2 Lower surface plate 3 Workpiece 4
Carrier 5 teeth 6 internal car 7 pin
Reference Signs List 8 Solar car 9 Pin 10 Pin shaft 10a Pin shaft shaft 10b Pin shaft base 11a Groove 11b Open hole 12 Collar 13 Cap

Claims (3)

[Claims] 1. A processing machine for clamping a plate-shaped workpiece between upper and lower facing plates while being fitted into a holding hole of a carrier, rotating under pressure, and simultaneously processing both surfaces thereof. The teeth formed on the outer periphery of the carrier are erected on a pin erected on a sun wheel installed at the center of the stool and an internal wheel installed along the outer edge of the stool. In the double-side polishing machine in which the carrier is rotated by the rotation of the sun wheel and the internal wheel, the pin is formed of a pin shaft and a collar fitted to an outer peripheral portion thereof. Wherein the pin shaft has a groove on its surface and the lower end of the groove has an open hole in the outer peripheral direction of the pin. 2. The pin shaft according to claim 1, wherein the groove on the surface of the pin shaft is continuous from the upper portion to the lower end portion of the pin shaft.
Item 2. Double-side polishing machine. 3. The double-side polishing machine according to claim 1, wherein the surface area occupied by the entire groove is 10 to 90% of the surface area of the entire pin shaft.