JP2001088020A - Polishing method and device for workpiece - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrain generation of hydroplaning phenomenon and prevent a workpiece from being separated from a carrier to thereby surely polish the same by properly controlling the supply quantity of polishing material slurry in polishing the same with a flat surface polishing device. SOLUTION: A workpiece W is held by a carrier 15 rotating while revolving around a sun gear 11, the workpiece W is held from both sides thereof between upper and lower surface plates 13, 14 capable of rotating, the rotational speed and work load of the plates 13, 14 are controlled to plural steps while supplying polishing material slurry to between the plates 13, 14, and the work W is polished. In this case, during the time when the rotational speed and/or work load of the plates 13, 14 are small at the initial stage of work, the supply quantity of slurry made by a pump 33 is restrained to a lower level than that at the time of normal work, and is increased according to the increase of the rotational speed and/or the work load.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a means for polishing both surfaces of a flat work held by a carrier with upper and lower platens. The present invention provides a means suitable for the polishing of the workpiece.

[0002]

2. Description of the Related Art As shown conceptually in FIG. 3, for example, a planar polishing apparatus such as a polishing machine or the like is provided with a sun gear 1, an internal gear 2, and an upper and lower fixed gears which are located on the same axis and are rotatably driven. And a carrier 5 that meshes with the gears 1 and 2 and moves in a planetary manner. The work W held in the work holding hole 5a of the carrier is placed on the upper and lower platens 3 and 4. , And both platens 3, 4
While supplying the abrasive slurry through the nozzle 6
Both surfaces of the work W are polished by the rotating platens 3 and 4.

The polishing of the work W by the above-mentioned polishing apparatus is usually performed based on a processing process as shown in FIG. That is, the slurry at a steady flow rate is supplied at the same time as the start of rotation of the surface plate, and after passing through the first processing step in which the rotation speed and processing load of the surface plate are the smallest, the rotation speed and the processing load are medium speed and medium load conditions. In the second machining step, the machining is completed through the third machining step in a high-speed and high-load state where the platen rotation speed and the machining load are the largest, and during this time, it is usual that a constant flow rate of the slurry is continuously supplied. It is.

However, there has been a problem that such a work is conventionally polished such that the work W tends to come off from the work holding hole 5a of the carrier 5 during processing. This problem is particularly likely to occur when polishing a thin work such as a glass disk or a quartz disk. That is, among thin workpieces, there are extremely thin ones having a thickness of, for example, 0.6 mm, 30 μm, or 16 μm, and a carrier holding such an extremely thin workpiece is naturally formed to be thinner. I have. When such a thin work is polished by the above-mentioned polishing apparatus, the distance H between the upper and lower platens 3, 4 is the same as the thickness of the work W, and is very small.
Since the processing load by the surface plate is set small in the initial stage of processing, when a steady flow rate of slurry is supplied between the narrow surface plates 3 and 4 simultaneously with the start of processing, the upper surface plate 3 is pushed up by the falling water pressure of the slurry. The interval H increases, and the work W floats up and easily comes off the carrier 5.

[0005]

SUMMARY OF THE INVENTION A technical problem of the present invention is that when a workpiece is polished by a plane polishing apparatus, the amount of the abrasive slurry supplied is appropriately controlled in accordance with the increase or decrease of the processing load. The purpose of the present invention is to prevent the work from coming off the carrier due to the upper surface plate being pushed up by the water pressure, so that the work can be surely polished.

[0006]

According to the present invention, a work is held on a carrier which rotates while revolving around a sun gear, and the work is held on a rotatable upper and lower platen. When the workpiece is polished by controlling the rotation speed and the processing load of the surface plate in a plurality of stages while supplying the abrasive slurry between the both surface plates while sandwiching from both sides, the processing load by the surface plate after the start of the processing. While the value is small, the amount of slurry supplied by the pump is controlled to be smaller than the maximum flow rate, and the amount of slurry supplied is increased as the processing load increases.

According to the present invention having the above structure, the amount of slurry supplied by the pump is suppressed to less than the maximum flow rate while the processing load by the surface plate is small, and the amount of slurry supplied is increased as the processing load increases. Therefore, when the processing load is small, a large amount of slurry is supplied at a time, so that the upper platen is pushed up, and it is possible to surely prevent a problem such that the work jumps out of the carrier and to polish the work reliably. be able to.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows an embodiment of a flat-surface polishing apparatus according to the present invention. The flat-surface polishing apparatus includes a sun gear 11 located at a center, an internal gear 12 positioned so as to surround the sun gear 11, The sun gear 11 and the internal gear 12 mesh with the sun gear 1
A plurality of carriers 15 which make a planetary motion around 1 and upper and lower platens 13, which polish the work W held in a work holding hole 15a of the carrier 15 from both sides thereof,
14 is provided.

The above-mentioned sun gear 11, internal gear 12 and lower platen 14 are provided with drive shafts 11a,
The drive unit 1 is mounted on the drive shafts 12a, 14a via gears 11b, 12b, 14b at the lower end of each drive shaft.
The drive 17 is connected to a controller 16.

On the other hand, the upper platen 13 is provided with a pressing cylinder 2 for applying a processing load to the rod 19a of the lifting cylinder 19 attached to the machine body.
0, a pressure rod 20 extending from the pressure cylinder 20
a, a platen suspension 22 attached to the lower end of the pressure rod via a self-aligning bearing 21, a plurality of studs 23 hanging from the platen suspension 22, and a relay fixed to the lower end of the stud 23 It is attached via a plate 24. In the work processing position of FIG. 1 in which the upper platen 13 is lowered by the extension of the lifting cylinder 19, the locking member 25 on the relay plate 24 engages with the driver 26 at the upper end of the drive shaft 26a. While being driven and rotated by the driving device 17 via the driver 26, it is pressed by the pressurizing cylinder 20 to apply a predetermined processing load to the work W, and the upper platen 13 is raised by shortening the elevating cylinder 19. In the non-machining position, the locking member 25 comes off the driver 26. The drive shaft 26a is connected to the drive device 17 via a gear 26b at its lower end.

The polishing apparatus also includes upper and lower platens 13,
A slurry supply mechanism 30 for supplying an abrasive slurry is provided between the two. This slurry supply mechanism 30
Are mounted around the platen suspension 22 to receive the slurry from the discharge head 32 and a slurry tank 31 in which the slurry is stored, a pump 33 for supplying the slurry in the slurry tank 31 to the discharge head 32, and ,
An annular flow path member 34 having a groove-shaped cross section for uniformly distributing the received slurry over the entire circumference of the upper surface plate 13;
Nozzle 35 opened at a predetermined interval on the lower surface of 3
And a tube 36 connecting each nozzle 35 and the flow path member 34. The pump 33 is connected to the controller 16 and is configured so that the amount of slurry supplied can be increased or decreased by controlling the number of revolutions by the controller 16.

[0012] In the planar polishing apparatus having the above configuration,
With the upper platen 13 raised to the non-machining position, each carrier 1
When the work W is supplied to the work holding hole 15a of No. 5, the upper surface plate 13 is lowered to the position shown in FIG. When the pump 33 is activated, the abrasive slurry is supplied between the upper and lower platens 13 and 14 through the nozzle 35, and the carrier 15 revolves around the sun gear 11 by the rotation of the sun gear 11 and the internal gear 12. The work W is polished by the upper and lower surface plates 13 and 14 by starting a planetary motion of rotating while the upper and lower surface plates 13 and 14 start rotating at a predetermined speed in a predetermined direction. The machining is performed by controlling the driving device 17, the pressurizing cylinder 20 and the pump 33 with the control device 16.
For example, it is performed based on a processing process as shown in FIG.

In this working process, the rotational speeds and working loads of the bases 13 and 14 are controlled in substantially the same manner as in the conventional example shown in FIG. That is, in the first processing step immediately after the start of processing, the rotation speed and the processing load of the surface plates 13 and 14 are suppressed to the minimum low speed and low load state, and in the subsequent second processing step, the rotation speed and the processing load are reduced. Is increased to a medium speed and a medium load state larger than the first processing step, and in a subsequent third processing step, the state is increased to a higher speed and a higher load state than the second processing step. After the polishing is performed for a required time in the above, the processing is completed in a fourth processing step.

On the other hand, the slurry supply amount is controlled so that an appropriate flow rate of slurry is supplied for each processing step, unlike the conventional case. That is, in the first processing step in which the processing load is the smallest, the slurry supply amount is suppressed to the minimum and the small amount state, and in the second processing step in which the processing load is increased to the medium load state, the slurry supply amount is correspondingly changed. In the third processing step in which the amount is increased to the medium amount and the processing load is the largest, the slurry supply amount is also increased to the large amount state which is the maximum flow rate. For example,
Processing load is 10 to 30 g / c in the first processing step
m ² , the slurry supply rate is also suppressed to 2 to 5 l / min, and the processing load is 40 to 50 in the second processing step.
g / cm ² , the slurry supply rate is 5 to 8 l / min.
When the processing load becomes 50 to 100 g / cm ² in the third processing step, the slurry supply amount also becomes 5
The flow rate is adjusted such that the amount is increased to ｌ15 l / min. A rinse liquid such as pure water is supplied between the upper and lower platens 13 and 14 in the fourth step when the processing is completed. The rinse liquid is supplied from the rinse liquid source (not shown) by the slurry supply mechanism 30 to the nozzle 6. Done through.

As described above, in a machining step in which the machining load is small, such as in the initial stage of machining, the amount of slurry supply is controlled to be smaller than the maximum flow rate required during steady machining, and the amount of slurry supply is increased in accordance with the increase in machining load. By doing so, it is possible to reliably prevent the work W from jumping out of the carrier 15 due to the upper platen 13 being pushed up by the water pressure of the slurry. In this case, if the supply amount of the slurry is too small, the surface of the work W is easily scratched. Therefore, the slurry supply amount for each processing step is determined by both the rising of the upper platen 13 and the surface damage of the work W. It is desirable to set the size so that it does not occur. More preferably, the upper platen 13
The flow rate is set to a maximum flow rate within a range in which no floating occurs or a flow rate close to the maximum flow rate. The appropriate flow rate of such a slurry differs depending on the processing conditions such as the type of the work W, the rotation speed of the platen, and the processing load, and is obtained through experiments, experiences, and the like.

The working process shown in FIG. 2 is a preferred example and is not limited to this. For example, the working steps having different working loads may be three or less, or may be divided into five or more. It does not matter.

In the above-described processing, a case is described in which the rotation speed of the surface plate and the processing load are controlled synchronously, but they can be controlled separately.

[0018]

As described above, according to the present invention, the supply amount of the abrasive slurry is kept small while the processing load on the surface plate is small, such as at the beginning of processing, and the slurry supply amount is increased with the increase in the processing load. As a result, it is possible to prevent the work from jumping out of the carrier by eliminating the lifting of the platen caused by the supply of a large amount of slurry when the processing load is small, so that the work can be surely held. Can be polished.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part showing an embodiment of a polishing apparatus according to the present invention.

FIG. 2 is a diagram showing a work polishing process by the polishing apparatus.

FIG. 3 is a partial sectional view of a conventional polishing apparatus.

FIG. 4 is a diagram showing a polishing process of a work by a conventional polishing apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Sun gear 12 Internal gear 13 Upper surface plate 14 Lower surface plate 15 Carrier 16 Control device 33 Pump

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshihiro Nakajo Saku-shi, Nagano Pref. DA09

Claims (2)

[Claims] A work is held on a carrier that rotates while revolving around a sun gear, and the work is sandwiched from both sides by a rotatable upper and lower platen, and an abrasive slurry is supplied between both platens. A method of polishing the work by controlling the rotation speed and the processing load of the platen in a plurality of stages, wherein the amount of slurry supplied by the pump is less than the maximum flow rate while the processing load by the platen after processing is started is small. A polishing method for a workpiece, characterized in that the amount of slurry supplied is increased as the processing load increases. 2. A carrier which rotates while revolving around a sun gear, a rotatable upper and lower platen for holding and polishing a work held by the carrier from both sides, and polishing between these platens. A pump for supplying the material slurry, and a control device capable of controlling the rotation speed of the platen, the processing load, and the amount of slurry supplied by the pump in a plurality of stages, respectively, the control device comprising: An apparatus for polishing a workpiece, characterized in that the amount of slurry supplied by a pump is kept below the maximum flow rate while the processing load by the surface plate is small, and the amount of slurry supplied is increased as the processing load increases.