JP5627114B2 - Thin plate workpiece grinding method and double-head surface grinding machine - Google Patents

Description

  The present invention relates to a method for grinding a thin plate workpiece used when grinding a thin plate workpiece such as a silicon wafer, and a double-head surface grinder.

  When grinding a thin plate-like workpiece such as a silicon wafer using a horizontal double-sided surface grinder, the workpiece supported by a pair of left and right static pressure pads in a non-contact manner is rotated around its center while rotating horizontally. Grind to a predetermined finish thickness by a pair of left and right grinding wheels rotating around the axis.

  The support system for rotatably supporting the work includes a direct contact support system (Patent Documents 1 and 2) for directly contacting and supporting the outer periphery of the work and a carrier support system for supporting the work via a carrier and a carrier ring ( Patent Document 3), and the direct contact support system includes a roller support system (Patent Document 1) and a belt support system (Patent Document 2).

  In the roller support method (Patent Document 1), the outer periphery of a disk-shaped workpiece is rotatably supported by a plurality of support rollers in the circumferential direction, and the workpiece is rotated around the center by any one of the support rollers. Yes. In the belt support system (Patent Document 2), the outer periphery of a disk-shaped workpiece is rotatably supported by two sets of support belts in the circumferential direction, and the workpiece is rotated around the center by the support belt.

  In the carrier support system (Patent Document 3), a work is mounted in a mounting hole of a thin plate-like carrier whose outer periphery is fixed to the carrier ring, and the carrier ring is provided by a plurality of support rollers arranged substantially equally on the outer periphery. The work is rotated about the center through the carrier ring and the carrier by a drive gear that contacts and supports and meshes with the ring gear on the inner peripheral side of the carrier ring.

Japanese Patent Laid-Open No. 10-175144 Japanese Patent Laid-Open No. 10-156681 JP 2005-205528 A

  In the conventional direct contact support method, the outer periphery of the workpiece is directly supported by a support roller or a support belt, and the workpiece is rotated by driving the support roller or support belt. Has a problem that it cannot be adopted.

  On the other hand, the carrier support method uses a thin plate-like carrier whose outer periphery is fixed to the carrier ring, and drives and rotates the carrier ring supported by the outer peripheral support roller with the workpiece fitted in the mounting hole. Compared with the direct contact support system, there is an advantage that a thin work can be ground with high accuracy. However, since the conventional carrier support system employs a contact support system in which the carrier ring is contact-supported by a plurality of support rollers arranged substantially equally on the outer periphery thereof, there are the following problems.

  In other words, conventionally, the guide rings are held in contact with a plurality of support rollers so that the swing of each support roller is transmitted to the carrier ring, and the rotation accuracy of the workpiece deteriorates due to the combination. There is a problem to do. In addition, if there is a defect in the mounting accuracy of the support roller support shaft, especially the parallelism with the rotation center of the carrier ring, a force other than rotation is transmitted to the carrier ring and the carrier ring and the workpiece are inclined. is there.

  Also, use a support roller that has been cast and finished with a resin material such as high-hardness urethane so that the carrier ring is hard to damage and can be securely supported without slipping. However, in this case, the support roller is made of resin, and thus has the following problems. That is, it is difficult to stably obtain the roundness required for the support roller, and the quality of the support roller is likely to be deteriorated over time, and the support roller is likely to be worn. .

  In view of such a conventional problem, the present invention can reduce the influence of external force applied to the carrier ring and improve the grinding accuracy of the workpiece, and can perform good grinding over a long period without causing problems such as friction. An object of the present invention is to provide a method for grinding a thin plate workpiece and a double-head surface grinder capable of maintaining accuracy.

The thin plate workpiece grinding method according to the present invention includes a pair of grinding workpieces while the thin plate workpiece mounted on the carrier is statically supported by a pair of static pressure pads in a non-contact manner and the workpiece is rotated via the carrier. When grinding both surfaces of the workpiece with a grindstone, the outer circumferential surface of the carrier ring arranged substantially concentrically on the outer circumferential side of the carrier is statically supported by a plurality of static pressure carrier guides in the circumferential direction without contact. It is.

The double-sided surface grinder according to the present invention statically supports a thin plate workpiece mounted on a carrier by a pair of static pressure pads in a non-contact manner, and rotates the workpiece through the carrier while using a pair of grinding wheels. In the double-sided surface grinding machine for grinding both surfaces of the workpiece, a plurality of static pressure carrier guides are provided in the circumferential direction to support the outer circumferential surface of the carrier ring arranged substantially concentrically on the outer circumferential side of the carrier in a non-contact manner. It is a thing.

  The carrier ring may have a cylindrical outer peripheral surface, and the static pressure carrier guides may be arranged substantially equally in the vicinity of the outer peripheral surface. The static pressure carrier guide may be fixed. The static pressure carrier guide may be floatable.

  The hydrostatic carrier guide is pivotally supported by a floating shaft that is substantially parallel to the center of rotation of the carrier ring, and a hydrostatic fluid is supplied to the hydrostatic carrier guide from the outer peripheral surface of the carrier ring. Pockets may be provided substantially symmetrically in the direction of rotation of the carrier ring with respect to the floating axis.

A support arm pivotally supported by a pivot substantially parallel to the center of rotation of the carrier ring and supporting at least a portion of the static pressure carrier guide so as to be movable in a perspective direction with respect to the carrier ring; Drive means for rotating the arm around the pivot axis and stopper means for stopping the support arm at a predetermined position may be provided.

  The static pressure carrier guide may be changeable between a fixed state and a floating state floating around a floating axis substantially parallel to the rotation center of the carrier ring.

Comprising three or more of the static pressure carrier guide which are arranged substantially equidistant on the outer periphery of the carrier ring, out of the three or more static pressure carrier guide, the position of at least one of said static pressure carrier guide The three or more static pressure carrier guides may be provided with a gap adjusting means for adjusting a gap between the static pressure surface and the outer peripheral surface of the carrier ring by adjusting in a substantially diameter direction of the carrier ring.

  According to the present invention, since the carrier ring is statically supported by the static pressure carrier guide, the influence of external force applied to the carrier ring can be reduced, the workpiece grinding accuracy can be improved, and problems such as friction do not occur. There is an advantage that good grinding accuracy can be maintained over a long period of time.

1 is a schematic side view of a horizontal double-sided surface grinding machine showing an embodiment of the present invention. It is the same schematic sectional drawing. It is an enlarged side view of the principal part. It is an expanded sectional view of the support part of the same static pressure carrier guide. It is sectional drawing of the fixed state of the static pressure carrier guide. It is the XX sectional view taken on the line of FIG. It is sectional drawing of the same static pressure carrier guide. It is a bottom view of the static pressure carrier guide. It is a static pressure circuit diagram of the static pressure carrier guide. It is the YY sectional view taken on the line of FIG. It is sectional drawing of the floating state of the static pressure carrier guide. It is a figure which shows the measurement result of the roundness of a carrier ring. It is a figure which shows the measurement result of the outer periphery runout of the carrier ring by the conventional contact support system. It is a figure which shows the measurement result of the outer periphery runout of the carrier ring by the non-contact support system of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The drawing illustrates a horizontal double-sided surface grinding machine employing the present invention. As shown in FIGS. 1 and 2, the horizontal double-head surface grinding machine includes a pair of left and right static pressure pads 1 that are arranged to face each other and support a thin plate-like workpiece W in a non-contact manner, and each static pressure pad 1. Corresponding to the notch 2 of the pressure pad 1, the left and right side surfaces of the workpiece W are rotatably arranged around the grinding wheel shaft in the left and right direction and moved in the axial direction of the cutting shaft and supported by the static pressure pad 1. A pair of left and right grinding wheels 3 for grinding the workpiece, a carrier 4 for rotating the mounted workpiece W around the center of the cutting shaft while being held by the static pressure pad 1, and a carrier ring 5 for supporting the outer periphery of the carrier 4 And a plurality of static pressure carrier guides 6a and 6b which are arranged substantially equally on the outer periphery of the carrier ring 5 and statically support the carrier ring 5 in a non-contact and rotatable manner from the outer periphery.

  Each static pressure pad 1 is arranged on the opposite end side of a pair of left and right movable bases 8 that can move in the axial direction of the cutting shaft, and cuts between a forward position that holds the workpiece W and a retracted position that retracts from the workpiece W. The workpiece W is movable in the axial direction, and the workpiece W is statically supported in a non-contact manner through a hydrostatic fluid such as hydrostatic water supplied to the hydrostatic surface facing the workpiece W at the forward movement position.

The carrier 4 is a thin plate-like disk that is thinner than the finished dimensions of the workpiece W, and has mounting holes 9 in which the workpiece W is detachably mounted. As shown in FIGS. 1 to 4, the carrier 4 has a carrier ring 5 disposed substantially concentrically on the outer periphery thereof, and a holding ring 10 that is fixed in the carrier ring 5 and presses the outer periphery of the carrier 4 toward the carrier ring 5. And is supported by. The carrier ring 5 has a cylindrical outer peripheral surface 12 formed concentrically with respect to the center of rotation of the carrier 4, and both end surfaces in the axial direction are on the outer peripheral side of the static pressure surface of the static pressure pad 1. It faces the step 11 with a gap. The carrier 4, the carrier ring, and the presser ring 10 constitute carrier means 7 .

  The carrier ring 5 is made of a ceramic material such as alumina, which is thin and easy to increase the roundness, but may be made of a metal such as stainless steel. A ring gear 13 is provided on the inner periphery of the presser ring 10, and the carrier means 7 including the carrier 4 and the carrier ring 5 is rotationally driven by a drive gear 14 that meshes with the ring gear 13.

  Each of the static pressure carrier guides 6 a and 6 b is mounted on the opposite end side facing the carrier 4 of one movable table 8, and three or more of the static pressure carrier guides 6 a and 6 b are arranged on the outer periphery of the carrier ring 5 in the circumferential direction. For example, in this embodiment, four static pressure carrier guides 6a and 6b are arranged in a substantially equal arrangement, and each of the static pressure carrier guides 6a and 6b is as shown in FIG. 3, FIG. 4, and FIG. These are pivotally attached to the movable base 8 via the floating shafts 15a and 15b, and are mounted so as to be changeable between a fixed state and a floating state via the fixing means 16a and 16b and the restricting means 17a and 17b.

  As shown in FIGS. 7 and 8, each of the static pressure carrier guides 6 a and 6 b has a shaft hole through which the floating shafts 15 a and 15 b are inserted substantially at the center in the rotation direction of the carrier ring 5 (hereinafter simply referred to as the rotation direction). 20, two pin holes 21 arranged on both sides of the shaft hole 20, a static pressure surface 22 facing the outer peripheral surface 12 of the carrier ring 5 with a slight gap, and on the static pressure surface 22 side Two provided static pressure pockets 23 and an escape groove 24 disposed between the two static pressure pockets 23 are provided. The floating shafts 15 a and 15 b, the pin hole 21, and the shaft hole 20 are substantially parallel to the rotation axis and the cutting axis of the carrier ring 5, and the pin hole 21 is disposed substantially symmetrically on both sides in the rotational direction with respect to the shaft hole 20. ing.

  The static pressure surface 22 of each of the static pressure carrier guides 6 a and 6 b is formed in an arc shape along the outer peripheral surface 12 of the carrier ring 5, and a minute gap (for example, about 10 to 30 μm) is formed between the outer peripheral surface 12 of the carrier ring 5. It is placed diametrically opposed. The static pressure pocket 23 is for supplying a static pressure fluid such as static pressure water between the static pressure surface 22 of the static pressure carrier guides 6 a and 6 b and the outer peripheral surface 12 of the carrier ring 5, and is recessed from the static pressure surface 22. And it is comprised by the recessed part long in a rotation direction, and is arrange | positioned substantially symmetrically on both sides of the rotation direction with respect to floating shaft 15a, 15b and the shaft hole 20. As shown in FIG. Each static pressure pocket 23 is connected to a supply source 29 of a static pressure fluid from an internal communication hole 25 through a flexible hose 26 opposite to the static pressure surface 22.

  Among the static pressure carrier guides 6a and 6b, two static pressure carrier guides 6a and 6b opposed to each other in the diameter direction of the carrier ring 5 are supplied with static pressure fluid via the same circuit 27 as shown in FIG. Connected to source 29. Each circuit 27 is provided with a pressure regulating valve 30 and a flow meter 31, and the pressure and flow rate are managed by these.

  As shown in FIGS. 3, 4, and 6, the upper two static pressure carrier guides 6 a are mounted on a support arm 34 that is pivotally attached to a movable base 8 by a pivot 33, and is a carrier means 7. When attaching / detaching, the support means 34 is swung around the pivot 33 by the driving means 19 so that the upper static pressure carrier guide 6a is moved in the perspective direction of the carrier ring 5. The pivot 33 is substantially parallel to the floating shaft 15a.

  A static pressure carrier guide 6a is mounted in the accommodating portion 35 at one end side of the support arm 34, and a cylinder 36 constituting the driving means 19 is connected to the other end side. As shown in FIGS. 4 and 6, the accommodating portion 35 is provided between the side walls 35 a and 35 b of the support arm 34 so as to penetrate in the diameter direction of the carrier ring 5, and the static pressure carrier guide is provided in the accommodating portion 35. 6a is accommodated, and the static pressure carrier guide 6a is pivotally supported by a floating shaft 15a that passes through the side walls 35a and 35b on both sides of the accommodating portion 35 and is inserted into the support arm 34. As shown in FIGS. 3 and 6, the static pressure carrier guide 6a in the accommodating portion 35 can be fixed to the support arm 34 at an appropriate angle by the fixing means 16a, and when the fixing means 16a is released, by the restricting means 17a. Floating is possible within the restricted floating range.

The fixing means 16a has a fixing pin 39 press-fitted into one pin hole 21 of the static pressure carrier guide 6a, and a pin hole 38b into which the fixing pin 39 fits and is detachably mounted on the side surface of the support arm 34. And a fixing bracket 38. The fixing bracket 38 is detachably pivotally attached to the support arm 34 by a fixing bolt 40 on the base side, and the angle of the fixing bracket 38 can be adjusted around the fixing bolt 40 by an adjustment bolt 41 that passes through the long hole 38a and is screwed to the support arm 34 side. It is. The pin hole 38b is provided at the tip of the fixed bracket 38, and the fixed pin 39 is fitted in the pin hole 38b so as to be detachable. The restricting means 17 a is configured by the other pin hole 21 of the static pressure carrier guide 6 a and a restricting pin 42 that passes through the accommodating portion 35 and is inserted into the pin hole 21, and between the restricting pin 42 and the pin hole 21. A gap corresponding to the floating range is provided.

  The cylinder 36 is interposed between the connecting pin 44 of the support arm 34 and the pivot pin 45 of the movable base 8, and the support arm 34 is swung around the pivot 33 to move the static pressure carrier guide 6 a with respect to the carrier ring 5. It moves in the perspective direction (substantially in the diameter direction). Stopper means 47 for stopping the support arm 34 at a predetermined position is provided on one end side of the support arm 34.

  As shown in FIGS. 3 and 6, the stopper means 47 includes a contact portion 48 fixed to the movable base 8, and a screw-type stopper 49 screwed to one end side of the support arm 34 so as to be adjustable. By adjusting the stopper 49, the distance between the static pressure surfaces 22 of the static pressure carrier guides 6a, 6b on both sides in the diametrical direction of the carrier ring 5 changes, and is approximately at the center between the static pressure carrier guides 6a, 6b. The gap can be adjusted so that the carrier ring 5 is positioned. Therefore, the stopper means 47 also serves as a gap adjusting means for adjusting the gap between the static pressure surface 22 of the static pressure carrier guide 6a and the outer peripheral surface 12 of the carrier ring 5.

  As shown in FIGS. 3, 5, 10, and 11, the lower two static pressure carrier guides 6b are provided with a floating shaft 15b and a fixing means 16b including a fixing bracket 50 (FIGS. 3, 5, and 11). 10) and the restricting means 17b (see FIG. 11) so as to be changeable between a fixed state and a floating state.

  The floating shaft 15 b is fixed to the movable table 8. The fixed bracket 50 is mounted so that one end side in the longitudinal direction can be reversed with respect to the floating shaft 15b and the angle can be adjusted around the floating shaft 15b. The other end side has a fixing hole 53 and a diameter larger than that of the fixing hole 53. Floating recesses 54 are provided. The static pressure carrier guide 6b is pivotally supported by a floating shaft 15b, and an engagement pin 55 is press-fitted into one pin hole 21. The amount of protrusion of the engaging pin 55 toward the fixed bracket 50 is such that when the floating recess 54 is directed toward the static pressure carrier guide 6b, it does not engage with the fixed hole 53.

As shown in FIGS. 3, 5, and 10, the fixing means 16 b for fixing the static pressure carrier guide 6 b is configured by the engaging pin 55 and the fixing hole 53 of the fixing bracket 50. The static pressure carrier guide 6b is fixed by being inserted into the fixing hole 53 .

  Further, as shown in FIG. 11, the restricting means 17 b for restricting the floating range of the static pressure carrier guide 6 b includes an engaging pin 55 and a floating recess 54 of the fixed bracket 50, and the engaging pin 55 is formed in the floating recess 54. The gap between the two when they enter corresponds to the floating range of the static pressure carrier guide 6b.

  One end of the fixed bracket 50 is provided with a split grip portion 56 for gripping the base portion of the floating shaft 15b and a fastening bolt 57 for fastening the grip portion 56. The fixed bracket 50 is attached to the floating shaft 15b. The angle can be adjusted. The fixing hole 53 and the floating recess 54 are formed long in the longitudinal direction of the fixing bracket 50 so that the angle of the fixing bracket 50 can be adjusted around the floating shaft 15b.

  When grinding the workpiece W, the workpiece W mounted on the carrier 4 is statically supported by the pair of static pressure pads 1 from both the left and right sides in a non-contact manner, and each of the workpieces 5 arranged on the outer periphery of the carrier ring 5 is arranged in a substantially equal distribution. The static pressure fluid is supplied from the static pressure pockets 23 of the static pressure carrier guides 6a and 6b to the outer peripheral surface 12 of the carrier ring 5, and the carrier rings 5 are not contacted by the static pressure carrier guides 6a and 6b via the static pressure fluid. The carrier ring 5 is driven by the drive gear 14 via the ring gear 13 and the workpiece W mounted on the carrier 4 is rotated around the rotation axis, and the pair of grinding wheels 3 Grind both sides to the specified finish dimension.

  In this way, the carrier ring 5 can be statically supported in a non-contact manner by the outer periphery of the static pressure carrier guides 6a and 6b. That is, between the outer peripheral surface 12 of the carrier ring 5, there is a static pressure fluid supplied from each of the static pressure carrier guides 6 a and 6 b, and the carrier ring is passed through the static pressure fluid by each of the static pressure carrier guides 6 a and 6 b. 5 can be supported statically from the outer peripheral side without contact. On the other hand, between the both end faces of the carrier ring 5, there is a static pressure fluid supplied from each static pressure pad 1 as in the prior art, and each static pressure pad 1 does not contact the static pressure via the static pressure fluid. I can support it.

  For this reason, the outer periphery and both end faces of the carrier ring 5 are all supported in a static pressure manner without contact, and the carrier ring during the grinding cycle is compared with the conventional contact support method in which the carrier ring 5 is supported by the guide roller. The external force applied to the workpiece W from 5 through the carrier 4 is reduced, and the rotational accuracy (mainly the outer runout) of the workpiece W can be improved. Therefore, the grinding accuracy of the workpiece W can be improved.

  In addition, since the carrier ring 5 is rotatably supported by the static pressure carrier guides 6a and 6b via the hydrostatic fluid in a non-contact manner, there is a problem such as wear due to contact between members as in the case of the contact support method. And good rotation accuracy can be maintained semi-permanently. For this reason, deterioration of the grinding accuracy of the workpiece W due to wear or the like, an increase in maintenance man-hours, generation of consumables costs, etc. can be prevented.

The respective hydrostatic carrier guides 6a disposed substantially square uniformly arranged on the outer periphery of the carrier ring 5, among 6b, hydrostatic carrier guide 6a that is disposed on both sides of the diameter direction of the carrier ring 5, 6b are in FIG. 9 As shown, the gap between the static pressure surface 22 of the static pressure carrier guides 6a and 6b and the outer peripheral surface 12 of the carrier ring 5 is connected to the same circuit 27 where the pressure and flow rate of the static pressure fluid are sufficiently large. When the pressure fluctuates, a force that tries to equalize the pressure in the same circuit 27 works and the carrier ring 5 tries to maintain a fixed position, so that stable rotation accuracy can be obtained.

  That is, when the pressure balance between the pair of opposed static pressure carrier guides 6a and 6b is lost due to some cause, for example, when the gap between the lower static pressure carrier guide 6b and the carrier ring 5 becomes narrow, The pressure in the static pressure pocket 23 of the static pressure carrier guide 6b increases. On the other hand, the gap between the upper static pressure carrier guide 6a and the carrier ring 5 becomes wider, and the pressure in the static pressure pocket 23 of the static pressure carrier guide 6a decreases. Therefore, due to the pressure difference between the static pressure pockets 23 of the both static pressure carrier guides 6a and 6b, the carrier ring 5 moves so that the gaps between the both static pressure carrier guides 6a and 6b are even and keeps the fixed position. become.

  The outer peripheral surface 12 of the carrier ring 5 is a cylindrical surface that is substantially concentric with respect to the center of rotation of the carrier 4 and has a shape that does not have a groove or the like through which the pressure of the hydrostatic fluid escapes. Since the static pressure surfaces 22 of the static pressure carrier guides 6a and 6b are close to each other with a small gap, the carrier ring 5 can be stably supported by the static pressure fluid, and the stable rotation accuracy of the carrier ring 5 is obtained. be able to. Moreover, the static pressure surface 22 of each static pressure carrier guide 6a, 6b has two static pressure pockets 23 in the rotational direction of the carrier ring 5, and is divided into two by an intermediate relief groove 24. Each of the static pressure carrier guides 6a and 6b can balance the pressure of the static pressure fluid on both sides of the carrier ring 5 in the rotation direction.

  When the carrier means 7 is attached or detached, the support arm 34 is swung around the pivot 33 in the direction of the arrow a in FIG. 3 by the cylinder 36 as shown by a two-dot chain line in FIG. Are spaced apart in the diameter direction of the carrier ring 5. After the carrier ring 5 is put in a predetermined position, the support arm 34 is rotated around the pivot 33 in the direction indicated by the arrow a by the cylinder 36. When the static pressure surface 22 of the upper static pressure carrier guide 6a and the outer peripheral surface 12 of the carrier ring 5 become a predetermined gap, the stopper 49 abuts on the abutment portion 48 to restrict the rotation of the support arm 34.

  Thus, by driving the support arm 34 by the cylinder 36 and moving the upper static pressure carrier guide 6a, the distance between the pair of static pressure carrier guides 6a and 6b arranged on both sides in the diameter direction of the carrier ring 5 is achieved. Therefore, the carrier ring 5 can be easily taken in and out, and automation thereof can be easily achieved.

  Further, by adjusting the position where the screw type stopper 49 of the stopper means 47 abuts against the abutting portion 48, the gap between the hydrostatic surface 22 of each hydrostatic carrier guide 6a, 6b and the outer peripheral surface 12 of the carrier ring 5 can be arbitrarily set. Can be adjusted. That is, by adjusting the stopper 49, the position of the support arm 34 when the stopper 47 abuts against the abutting portion 48 changes, and between the hydrostatic surfaces 22 of the hydrostatic carrier guide 6 a on both sides in the diameter direction of the carrier ring 5. The interval of changes. When the static pressure fluid is supplied from the static pressure carrier guides 6a and 6b on both sides in the diametrical direction of the carrier ring 5 to the outer periphery of the carrier ring 5, the carrier ring is provided at substantially the center between the static pressure carrier guides 6a and 6b. 5 is located, and the distance between the outer peripheral surface 12 of the carrier ring 5 and the static pressure surfaces 22 of the static pressure carrier guides 6a and 6b on both sides substantially coincides. Accordingly, the static pressure surface 22 of each of the static pressure carrier guides 6a and 6b and the outer peripheral surface 12 of the carrier ring 5 according to the distance between the static pressure surfaces 22 of the static pressure carrier guides 6a and 6b on both sides in the diameter direction of the carrier ring 5 Can be adjusted.

  Each of the static pressure carrier guides 6a and 6b can be changed between a fixed state and a floating state, and can be properly used by changing the setup as necessary. For example, when the roundness of the carrier ring 5 is high and the carrier ring 5 can be reliably supported by static pressure, the static pressure carrier guides 6a and 6b are fixed, and the roundness of the carrier ring 5 is low. The static pressure carrier guides 6a and 6b can be in a floating state. Alternatively, the lower two static pressure carrier guides 6b may be fixed, and the upper two static pressure carrier guides 6a may be in a floating state.

3, FIG. 5, FIG. 6 , and FIG. 10 show a state in which the static pressure carrier guides 6a and 6b are fixed. When the upper static pressure carrier guide 6a is fixed, the fixing pin 39 of the static pressure carrier guide 6a is inserted into the pin hole 38b of the fixing bracket 38 and the fixing bracket 38 is fixed as shown in FIGS. The bolt 40 is pivotally attached to the support arm 34. In this state, when the fixing bracket 38 is rotated around the fixing bolt 40 within the range of the long hole 38a, the static pressure carrier guide 6a is rotated around the floating shaft 15a, and the static pressure carrier guide is formed on both sides of the floating shaft 15a. Since the gap between the static pressure surface 22 of 6a and the outer peripheral surface 12 of the carrier ring 5 changes, the adjustment bolt 41 may be fastened and fixed at the positions where the gap is substantially uniform on both sides of the floating shaft 15a.

  Since the adjustment margin for fixing the static pressure carrier guide 6a is normally within the range of the gap between the pin hole 21 and the restriction pin 42, the restriction pin 42 may remain inserted into the pin hole 21. Further, the size of the gap between the static pressure surface 22 of the static pressure carrier guide 6 a and the outer peripheral surface 12 of the carrier ring 5 is appropriately adjusted by the stopper means 47.

  When the lower static pressure carrier guide 6b is fixed, as shown in FIGS. 5 and 10, the engaging pin 55 is inserted into the fixing hole 53 between the static pressure carrier guide 6b and the fixing bracket 50, and the floating shaft is fixed. After fixing the angle of the fixed bracket 50 around the floating shaft 15b so that the gap between the hydrostatic surface 22 of the hydrostatic carrier guide 6b and the outer peripheral surface 12 of the carrier ring 5 is substantially equal on both sides of the 15b, tighten. The fixing bracket 50 is fixed to the floating shaft 15b by tightening the bolts 57. As a result, the lower static pressure carrier guide 6b is fixed.

  Even when the static pressure carrier guides 6a and 6b are fixed in this manner, there are two static pressure pockets 23 on the static pressure surface 22 of the static pressure carrier guides 6a and 6b. Since the static pressure fluid is supplied to the outer peripheral surface 12 of the carrier 5, the carrier ring 5 can be supported by the static pressure via the static pressure fluid. In addition, since each of the static pressure carrier guides 6a and 6b is in a fixed state, the carrier ring 5 can be prevented from fluctuating and the carrier ring 5 can be reliably supported by static pressure.

  When the upper static pressure carrier guide 6a is in a floating state, if the fixing bracket 38 is removed, the fixing pin 39 of the static pressure carrier guide 6a is released from the pin hole 38b of the fixing bracket 38, so that the static pressure by the fixing means 16a is removed. The carrier guide 6a can be unlocked. As a result, the static pressure carrier guide 6a can be floated around the floating shaft 15a within the gap between the regulating pin 42 and the pin hole 21.

  When the lower static pressure carrier guide 6b is brought into a floating state, the fixed bracket 50 is reversed as shown in FIG. 11, and the static pressure carrier guide 6b is mounted so as to float within the range of the regulating means 17b. . First, the static pressure carrier guide 6b is removed from the floating shaft 15b, and the fixed bracket 50 is reversed and attached to the floating shaft 15b. Next, the static pressure carrier guide 6b is fitted over the floating shaft 15b, and the engagement pin 55 is engaged with the floating recess 54 of the fixed bracket 50.

  Then, the fixing bracket 50 is adjusted around the floating shaft 15b so that the clearance between the static pressure surface 22 of the static pressure carrier guide 6b and the outer peripheral surface 12 of the carrier ring 5 is substantially equal on both sides of the floating shaft 15b. Fasten with 57. As a result, the static pressure carrier guide 6b can be floated around the floating shaft 15b within the gap between the engagement pin 55 and the floating recess 54.

  After the static pressure carrier guides 6a and 6b are allowed to float in this way, when static pressure fluid is supplied from the static pressure pockets 23 of the static pressure carrier guides 6a and 6b to the outer peripheral surface 12 of the carrier ring 5, The carrier ring 5 can be statically supported via the pressurized fluid. When there is a difference in the gap between the static pressure surface 22 of the static pressure carrier guides 6a and 6b and the outer peripheral surface 12 of the carrier ring 5 on both sides of the floating shafts 15a and 15b, the gaps on both sides of the floating shafts 15a and 15b are substantially the same. As described above, the static pressure carrier guides 6a and 6b float around the floating shafts 15a and 15b. Therefore, contact between the static pressure carrier guides 6a and 6b and the carrier ring 5 can be prevented in advance. Further, since there are regulating means 17a and 17b for regulating the floating range of the static pressure carrier guides 6a and 6b, unstable swinging of the static pressure carrier guides 6a and 6b around the floating shafts 15a and 15b can be prevented.

  In addition to using each of the static pressure carrier guides 6a and 6b in a fixed state or a floating state, for example, the lower two static pressure carrier guides 6b are fixed and the upper two mounted on the support arm 34 are fixed. The static pressure carrier guide 6a can be used by allowing it to float around the floating shaft 15a. In this case, the carrier ring 5 is stabilized by reducing the gap between the static pressure surface 22 of each of the static pressure carrier guides 6a and 6b and the outer peripheral surface 12 of the carrier ring 5 while facilitating the mounting and dismounting operation of the carrier ring 5. Can be statically supported.

  That is, when the upper static pressure carrier guide 6a is attached to the support arm 34 that rotates about the pivot 33, if the static pressure carrier guide 6a is fixed to the support arm 34, the static pressure carrier guide 6a is accumulated due to error accumulation or the like. May come into contact with the carrier ring 5, making it difficult to reduce the gap between the static pressure carrier guides 6 a and 6 b and the carrier ring 5. However, by mounting the static pressure carrier guide 6a on the support arm 34 so that it can float, the gap between the static pressure surface 22 of each of the static pressure carrier guides 6a and 6b and the outer peripheral surface 12 of the carrier ring 5 is reduced. The contact with the carrier ring 5 can be prevented by the floating of the upper static pressure carrier guide 6a.

  Incidentally, using the ceramic carrier ring 5, the non-contact support method of the present invention and the conventional contact support method using the support roller were verified, and the non-contact support method of the present invention compared to the conventional contact support method. The outer ring runout of the carrier ring 5 could be suppressed to about 1/5. FIG. 12 shows the measurement result of the roundness of the carrier ring 5. FIG. 13 shows the measurement results of the peripheral runout of each carrier ring 5 in the case of the conventional contact support system, and FIG. 14 shows the case of the non-contact support system of the present invention.

  As shown in FIG. 12, the carrier ring 5 is made of a ceramic having an outer periphery roundness of about 5 μm (measured value: 4.5 μm), and the carrier ring in each of the conventional contact support system and the non-contact support system of the present invention. A peripheral runout of 5 was measured. In the case of the conventional contact support system, the measured value of the outer runout is about 15 μm as shown in FIG. 13, and when the roundness of the outer circumference of the carrier ring 5 (about 5 μm) is subtracted from this, the outer runout is about 10 μm. Become. On the other hand, the measured value of the shake in the case of the non-contact support method is about 7 μm as shown in FIG. 14, and when the roundness of the outer circumference of the carrier ring 5 (about 5 μm) is subtracted from this, the outer runout is about 2 μm. Become.

  As a result, in the non-contact support system of the present invention, the outer peripheral runout of the carrier ring 5 can be suppressed to about 1/5 as compared with the conventional contact support system. For this reason, the rotation accuracy of the carrier ring 5 is directly transmitted to the workpiece W in contact with the inner periphery thereof via the carrier 4 and acts on the grinding point of the workpiece W sandwiched and fixed between the pair of grinding wheels 3 during the grinding cycle. Thus, the grinding of the workpiece W is immediately affected. However, by adopting the non-contact support method of the present invention, the influence of the outer peripheral runout of the carrier ring 5 can be reduced, and the workpiece W can be stably ground. Can be obtained.

  As mentioned above, although embodiment of this invention was explained in full detail, this invention is not limited to this embodiment, A various change is possible in the range which does not deviate from the meaning of this invention. For example, in the embodiment, each of the static pressure carrier guides 6a and 6b can be changed between a fixed state and a floating state, but all the static pressure carrier guides 6a and 6b may be fixed or floating. The plurality of static pressure carrier guides 6b on the side may be fixed, and the plurality of static pressure carrier guides 6a on the upper side may be floating.

  The static pressure carrier guides 6a and 6b are preferably arranged on the outer periphery of the carrier ring 5 at approximately equal intervals. However, as long as the carrier rings 5 can be supported by the plurality of static pressure carrier guides 6a and 6b, the carrier pressures 5 are approximately equally distributed. There is no need to place it. Further, when the static pressure carrier guides 6a and 6b are arranged at substantially equal intervals, the number of the static pressure carrier guides 6a and 6b may be three or more. When there are three static pressure carrier guides 6 a and 6 b, for example, two static pressure carrier guides 6 b are arranged on the lower side, and one upper static pressure carrier guide 6 a is arranged in the diameter direction of the carrier ring 5. It may be provided so as to be movable.

  When the static pressure pockets 23 are provided on the static pressure surfaces 22 of the static pressure carrier guides 6a and 6b substantially symmetrically in the rotational direction with respect to the floating shafts 15a and 15b, they are divided into two in the rotational direction as illustrated in the embodiment. Alternatively, one static pressure pocket 23 that is long in the rotation direction may be provided continuously. The drive means 19 for driving the support arm 34 may be constituted by a motor in addition to the cylinder 36, and the motor may be driven by the motor via a screw shaft or a gear.

  When the static pressure carrier guides 6a and 6b are moved in the perspective direction with respect to the carrier ring 5, the movable base 8 is provided with a guide mechanism in a substantially diametric direction of the carrier ring 5, and the static pressure carrier is movable along the guide mechanism. Guides 6a and 6b may be provided. In the embodiment, the stopper means 47 for stopping the support arm 34 at a predetermined position and the gap adjusting means for adjusting the gap between the static pressure surface 22 of the static pressure carrier guides 6a and 6b and the outer peripheral surface 12 of the carrier ring 5 are also used. However, both of these may be provided separately.

  All the static pressure carrier guides 6a and 6b may be connected to the supply source 29 of the static pressure fluid through the same circuit 27, or each of the static pressure carrier guides 6a and 6b is supplied via an independent pressure control circuit. It may be connected to the source 29. Further, in the embodiment, the horizontal surface grinder is exemplified, but the vertical surface grinder can be similarly implemented. The workpiece W may be anything as long as it is a thin plate.

DESCRIPTION OF SYMBOLS 1 Static pressure pad 3 Grinding wheel 4 Carrier 5 Carrier ring 6a, 6b Static pressure carrier guide 12 Outer peripheral surface 15a, 15b Floating shaft 16a, 16b Fixing means 17a, 17b Control means 19 Driving means 21 Pin hole 22 Static pressure surface 29 Supply source 33 Pivot 34 Support arm 47 Stopper means (gap adjusting means)
W Work

Claims (9)

A thin plate-like workpiece mounted on a carrier is statically supported in a non-contact manner by a pair of static pressure pads, and when the workpiece is rotated through the carrier, both sides of the workpiece are ground by a pair of grinding wheels. A method for grinding a thin plate-like workpiece, wherein the outer peripheral surface of a carrier ring disposed substantially concentrically on the outer peripheral side of a carrier is statically supported in a circumferential direction by a plurality of static pressure carrier guides in a non-contact manner. Double-head surface grinding in which a thin plate workpiece mounted on a carrier is statically supported by a pair of static pressure pads in a non-contact manner, and both surfaces of the workpiece are ground by a pair of grinding wheels while rotating the workpiece via the carrier. A double- sided surface grinding machine comprising a plurality of static pressure carrier guides in the circumferential direction for supporting non-contact static pressure on the outer circumferential surface of a carrier ring disposed substantially concentrically on the outer circumferential side of the carrier. .   The double-headed surface grinding machine according to claim 2, wherein the carrier ring has a cylindrical outer peripheral surface, and the static pressure carrier guides are arranged substantially equally in the vicinity of the outer peripheral surface.   The double-head surface grinder according to claim 2 or 3, wherein the static pressure carrier guide is fixed.   The double-head surface grinding machine according to claim 2 or 3, wherein the static pressure carrier guide is floatable.   The hydrostatic carrier guide is pivotally supported by a floating shaft that is substantially parallel to the center of rotation of the carrier ring, and a hydrostatic fluid is supplied to the hydrostatic carrier guide from the outer peripheral surface of the carrier ring. The double-head surface grinder according to any one of claims 2 to 5, wherein pockets are provided substantially symmetrically in the rotation direction of the carrier ring with respect to the floating shaft. A support arm pivotally supported by a pivot substantially parallel to the center of rotation of the carrier ring and supporting at least a portion of the static pressure carrier guide so as to be movable in a perspective direction with respect to the carrier ring; The double-head surface grinding machine according to any one of claims 2 to 6, further comprising a driving unit that rotates the arm around the pivot and a stopper unit that stops the support arm at a predetermined position.   The static pressure carrier guide can be changed between a fixed state and a floating state floating around a floating axis substantially parallel to the center of rotation of the carrier ring. Double-head surface grinding machine. Comprising three or more of the static pressure carrier guide which are arranged substantially equidistant on the outer periphery of the carrier ring, out of the three or more static pressure carrier guide, the position of at least one of said static pressure carrier guide 3. A gap adjusting means for adjusting the gap between a static pressure surface and an outer peripheral surface of the carrier ring by adjusting the three or more static pressure carrier guides by adjusting in a substantially diameter direction of the carrier ring. The double-head surface grinding machine according to any one of 8.

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