JPH10291146A - Machining method for wafer, plane surface grinder, and work rest - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably perform the cutting even when a diameter of a grinder is almost half of a diameter of a work, by regulating the position of a part of a work projected from a grinder by a work rest. SOLUTION: A pressure fluid is supplied to the upper and lower fluid hydrostatic pressure slides of upper and lower work rests, and a part 17b projected from an opposite face to a grinder, of the both faces of a work 17 is held by the upper and lower fluid hydrostatic pressure slides. The work 17 is held in such manner that a lower face of the work 17 is fixed on a slide face 77a of the lower fluid hydrostatic pressure slide, and the upper fluid hydrostatic pressure slide body is placed on an upper face of the work 17. On this occasion, the pressure is applied to the work 17 only by the dead weight of the upper fluid hydrostatic pressure slide body, so that a proper hydrostatic pressure fluid film is generated between the slide face of the upper fluid hydrostatic pressure slide body and the surface of the work 17.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for ultra-precise and parallel grinding of both surfaces of a hard thin wafer used for a semiconductor, and a surface grinder and a work rest used for the method. Things.

[0002]

A wafer cut from an ingot is rough in both surface roughness and shape accuracy. Therefore, when lapping is performed on a wafer that has been cut from an ingot, it takes a very long time and processing efficiency is not good. Also, in single-side grinding of a wafer, the shape of the wafer after one-side grinding from the ingot is flat during suction because the vacuum chuck chucks one side of the work, but the shape returns to its original shape when the work is removed from the vacuum chuck. There is a tendency.

According to the processing of a wafer by grinding which is attempted to improve the processing efficiency and the processing accuracy by the above-described lapping, required surface accuracy can be obtained in a short processing time. However, as long as the chucking of the wafer is performed by a vacuum chuck, the shape accuracy cannot be obtained.

The present invention is a further development of the above-mentioned prior art, and provides a wafer processing method capable of obtaining surface accuracy and shape accuracy in a short time, and a surface grinder and a work rest used in the processing method. The purpose is to:

[0005]

According to a first aspect of the present invention, there is provided a method of processing a wafer after cutting from an ingot.
A work supporting member that holds the wafer and rotates the wafer,
Prepare a double-sided surface grinder that grinds the grinding wheel end face with the grinding wheel end faces facing each other, and a work rest that holds the surface of the wafer that protrudes from the grinding wheel outer peripheral side of the contact part between the wafer and the grinding stone end face,
The wafer is rotated by the work supporting member and the wafer is held by the work rest, and the grindstone is applied to both sides of the wafer so that the center of the wafer passes through the grinding wheel. It is a processing method.

A second invention according to the present application is the wafer processing method according to the first invention, wherein a work rest acts on both surfaces of the wafer.

A third invention according to the present application is the method for processing a wafer according to the first invention, wherein the work rest acts on one surface of the wafer.

A fourth invention according to the present application is the method for processing a wafer according to the first invention, wherein both the grinding wheels are simultaneously ground using both grinding wheels having a grinding action.

According to a fifth aspect of the present invention, one of the grinding wheels uses a grinding wheel having a grinding action, and the other grinding wheel uses a grinding wheel having a grinding action that is smaller than the grinding wheel having the grinding action. A method for processing a wafer according to the first invention, characterized in that:

A sixth invention according to the present application is the wafer processing method according to any one of the first to fifth inventions, wherein a cup grindstone is used as the grindstone.

According to a seventh aspect of the present invention, there is provided a method of processing a wafer according to any one of the first to sixth aspects, wherein a grindstone having a diameter approximately half the diameter of the wafer is used. It is.

An eighth invention according to the present application is a double-sided surface grinder in which the end faces of a grindstone are arranged to face each other, and the plate face of a disc-shaped work is machined by the endface of the grindstone. Double-sided surface grinding, comprising: a work supporting member that rotates at a center parallel to the workpiece, a grindstone, and a work rest that holds a surface of the work that protrudes from the grindstone when the grindstone is applied to the surface of the work. It is a board.

A ninth invention according to the present application is the double-ended surface grinding machine according to the eighth invention, wherein the work rest holds both surfaces of the work.

A tenth invention according to the present application is the double-sided surface grinder according to the eighth invention, wherein the work rest holds one side of the work.

An eleventh invention according to the present application is the eighth, ninth, or tenth invention, wherein the work rest forms a hydrostatic bearing between the work rest and the work surface. 2. A double-sided surface grinder described in 1. above.

According to a twelfth aspect of the present invention, at least one side of the work rest is provided on the movable member so as to have a position for holding the work and a retracted position for not holding the work. Eighth to first features
A double-sided surface grinder according to any one of the first aspect of the present invention.

A thirteenth invention according to the present application is the double-headed grinding machine according to claim 12, wherein the moving member is a grindstone head.

A fourteenth invention according to the present application is characterized in that the moving member is an arm member supported by a pivot parallel to a grindstone axis and having a work rest attached to a tip thereof.
A double-sided surface grinder according to the invention.

A fifteenth invention according to the present application is characterized in that the moving member is an annular table rotatably supported at the same center as the grindstone shaft with respect to the grindstone table.
2 is a double-sided surface grinding machine according to the invention.

A sixteenth invention according to the present application is the double-ended surface grinding machine according to the fifteenth invention, wherein the annular table is supported by a hydrostatic slide.

According to a seventeenth aspect of the present invention, there is provided a method for processing a wafer after cutting from an ingot, comprising: a work supporting member for holding the wafer and rotating the wafer; a single-head surface grinder for grinding on a grinding wheel end face; Prepare a work rest that holds the surface of the wafer protruding from the outer periphery of the grindstone at the contact portion between the wafer and the end surface of the grindstone, rotate the wafer with the work support member, hold the surface of the wafer with the work rest, A wafer processing method characterized in that grinding is performed by applying a grindstone to a surface of a wafer such that a grinding wheel grinding action surface passes through the center.

An eighteenth invention according to the present application is the wafer processing method according to the seventeenth invention, wherein a cup grindstone is used as the grindstone.

A nineteenth invention according to the present application is characterized in that the work rest is used by acting on the surface of the wafer that is in contact with the grinding surface of the grindstone, and the non-ground surface of the wafer is supported by the work supporting member. 20. A wafer processing method according to the seventeenth or eighteenth.

According to a twentieth aspect of the present invention, there is provided a single-head surface grinding machine for processing a disk-shaped workpiece with an end face of a grindstone.
A work support member that holds the work and rotates the work around a center parallel to the grindstone axis, a grindstone, and a work rest that holds the surface of the work protruding from the grindstone when the grindstone is applied to the surface of the work. It is a single-head surface grinder characterized by having.

A twenty-first invention according to the present application is the single-head surface grinder according to the twentieth invention, wherein the work rest is provided on both sides of the work.

A twenty-second invention according to the present application is the single-head surface grinding machine according to the twentieth invention, wherein the work rest is provided on one surface side of the work.

A twenty-third invention according to the present application is the twentieth, twenty-first, or twenty-second invention, wherein the work rest constitutes a hydrostatic slide between the work rest and the work surface. 2 is a single-head surface grinding machine.

According to a twenty-fourth aspect of the present invention, the work rest is disposed on the moving member so as to take a position for holding the work and a retracted position for not holding the work. A single-head surface grinder according to any one of the twenty-third inventions.

A twenty-fifth invention according to the present application is the single-head surface grinding machine according to the twenty-fourth invention, wherein the moving member is a grindstone head.

A twenty-sixth invention according to the present application is characterized in that the moving member is an arm member supported by a pivot parallel to a grindstone axis and having a work rest attached to the tip.
A single-head surface grinder according to the invention.

A twenty-seventh invention according to the present application is characterized in that the moving member is an annular table rotatably supported at the same center as the grindstone shaft with respect to the grindstone table.
A single-head surface grinder according to a fourth aspect of the present invention.

A twenty-eighth invention according to the present application is the single-head surface grinding machine according to the twenty-seventh invention, wherein the annular table is supported by a hydrostatic slide.

A twenty-ninth invention according to the present application relates to a work rest of a double-headed grinding machine which performs a grinding by applying a rotation to a disk-shaped work and cutting a grinding action surface on both sides or a part of one side of the work at an end face of a grinding wheel. A work rest comprising a work holding member for holding a work surface by contacting or approaching through a pressure medium to both surfaces or one surface of the work with the work interposed therebetween.

According to a thirtieth aspect of the present invention, the work holding member of the work rest has a gap in a surface facing the work and has a fluid passage for supplying a pressure medium to the gap. The workrest according to the twenty-ninth aspect, wherein a hydrostatic slide is configured.

A thirty-first invention according to the present application is the workrest according to the twenty-ninth or thirtieth invention, wherein the pressure medium is a gas.

A thirty-second invention according to the present application is the workrest according to the thirty-ninth or thirtieth invention, wherein the pressure medium is a liquid.

A thirty-third invention according to the present application is characterized in that the work holding member is provided on a moving member that takes a position for holding the surface of the work and a position retracted from the work. A workrest according to any one of the thirty-second invention.

According to a thirty-fourth aspect of the present invention, the moving member moves the work holding member in a direction parallel to the plate surface of the work, and moves the work holding member between a position facing the work and a position not facing the work. A workrest according to a thirty-third aspect, characterized in that the workrest is a movable member to be taken.

According to a thirty-fifth aspect of the present invention, the moving member is a movable member that takes a position in contact with or approaching the plate surface of the work and a position facing the plate surface of the work and away from the work. A workrest according to a thirty-third aspect, characterized by:

A thirty-sixth invention according to the present application is the workrest according to the thirty-fifth invention, wherein the moving member doubles as a grindstone of a double-sided surface grinder.

A thirty-seventh invention according to the present application is characterized in that the moving member is an arm member rotatably supported by a pivot parallel to a grinding wheel axis of a double-sided surface grinder and having a work holding member at a tip. A workrest according to a thirty-fourth invention.

A thirty-eighth invention according to the thirty-fourth invention is characterized in that the moving member is provided on a grindstone table so as to be rotatable around a grindstone axis of a double-sided surface grinder. It is a rest.

A thirty-ninth aspect of the present invention is the workrest according to the thirty-eighth aspect, wherein the moving member forms a hydrostatic slide between the moving member and a grindstone table.

[0044]

2. Description of the Related Art Wafers such as silicon wafers are obtained by cutting an ingot with an inner saw or a wire saw and then finishing the polishing with a lapping machine.

On the other hand, finishing a wafer by grinding is disclosed, for example, in Japanese Utility Model Publication No. 3028734, Machine and Tool, 1995.
July to July, pages 60 to 64, Journal of the Japan Society of Abrasive Technology Vo
l. 39 No. 4 1995. JUL. It is disclosed on pages 20 to 23 and the like.

[0046]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to FIGS.

(Embodiment 1) As shown in FIGS. 1 to 4, a double-sided surface grinder according to this embodiment
1 on the lower frame 11 of the upper frame 1
11 is fixed. The lower frame 11 is provided with a lower grindstone rotating / elevating mechanism 12 and a work supporting member 14,
The upper frame 111 is provided with an upper whetstone rotating / elevating mechanism 13. Upper and lower rotating grindstones 15 and 16 are disposed on the two grindstone rotating / lifting mechanisms 12 and 13, respectively, and a grinding action surface 15 on the upper or lower end surface of the rotating grindstones 15 and 16 is provided.
a and 16a are arranged to face each other so as to be parallel to each other. Then, the thin plate-shaped work 17 is moved to the work support member 14.
In a state supported by the rotary grindstones 12 and 13, both surfaces of the work 17 are simultaneously ground by the grinding surfaces 15 a and 16 a of the rotary grindstones 15 and 16. It is supposed to be.

As shown in FIGS. 2 and 3, the grinding wheel base 20 of the lower grinding wheel rotating and lifting mechanism 12 is mounted on the lower frame 11 via a so-called V-flat guide 21 through the lower rotating grinding wheel 15.
Are supported so as to be movable in a direction perpendicular to the rotation axis of the rotator. The lower wheel head moving motor 22 is disposed on the side of the lower frame 11, and the rotation of the motor 22 causes the wheel head 20 to move horizontally through a ball screw 23 screwed into a ball nut 23 a fixed to the wheel head 20. Move laterally. The lower shaft support 24 is supported so as to be able to move up and down in the rotation axis direction of the lower rotary grindstone 15 via a vertical guide 24 a provided integrally with the grindstone table 20. The lower grindstone head elevating motor 25 is provided with a guide portion 24 at a lower portion of the grindstone head 20.
a rotation transmitting mechanism 2, which is provided on the side of
The lower shaft support 24 is moved up and down by being guided by the guide portion 24a via a ball screw 27 screwed into a ball nut (not shown) fixed to the bracket 6 and the bracket 24b fixed to the lower shaft support 24. This elevating stroke is slight.

The lower grindstone shaft 28 is rotatably supported in the lower shaft support 24, and the lower rotating grindstone 15 is mounted on the upper end thereof via a grindstone holder 29 integrally formed.

The grinding wheel drive motor 34 is disposed inside the lower shaft support 24, and its stator is fitted and fixed to the lower shaft support 24, and its rotor is fitted to and fixed to the lower grind shaft 28, and the grinding process is performed. The rotation of the motor 34 causes the lower rotating grindstone 15 to rotate at a high speed via the lower grinding wheel shaft 28.

As shown in FIG. 3, the upper shaft support 38 of the upper grindstone rotating / elevating mechanism 13 is supported via a guide 39 integrated with the upper frame 111 so as to be able to move up and down in the direction of the rotational axis of the lower grindstone 16. ing. The elevating motor 40 is disposed on the side of the upper frame 111, and the rotation of the motor 40 causes the bracket 3 fixed to the upper shaft support 38.
The upper shaft support cylinder 38 is moved up and down via a ball screw 41 screwed into a ball nut 41a fitted and fixed to 8a.

The upper grinding wheel shaft 42 is rotatably supported in the upper shaft support cylinder 38, and the upper rotating wheel 16 is mounted on the lower end thereof via a grinding wheel holder 43 formed integrally. A grindstone drive motor 48 is disposed inside the upper shaft support 38, and its stator is fitted and fixed to the upper shaft support 38, and its rotor is fitted and fixed to the upper grindstone shaft 42 and rotates the motor 48 during grinding. Thereby, the upper rotating grindstone 16 rotates at a high speed via the upper grindstone shaft 42.

As shown in FIGS. 2 and 4, the support table 52 of the work supporting member 14 has upper and lower grinding wheels rotating and lifting mechanisms 1.
It is disposed on the lower frame 11 between 2 and 13. The slide table 53 is supported by a pair of guide rails 54 disposed on both sides of the lower rotary grindstone 15 on the support table 52 so as to be movable in the same direction as the moving direction of the grindstone table 20 of the lower grindstone rotary elevating mechanism 12. Have been. As shown in FIG. 4, the slide table moving motor 55 is
The ball screw 56 connected to the motor shaft of the motor 55 is screwed into a ball nut 56a fixed to the slide table 53 by the rotation of the motor 55, so that the slide table 53 can be moved. ing.

An annular rotating plate 57 is disposed in the slide table 53 and is rotatably supported via three guide rollers 58 rotatably supported by the slide table 53 (see FIG. 5). . The rotating plate 57 has a work supporting plate 60 mounted on an annular thick outer peripheral frame 57a.
A gear 59 is formed on a lower outer periphery of the outer peripheral frame 57a. The work support plate 60 is formed thinner than the work 17,
The lower surface of the outer peripheral frame 57a is horizontally stretched via a tension mechanism (not shown) so as not to be bent and deformed by the gravity, and a set hole 60a for setting the work 17 in a detachable manner is formed at the center thereof. I have. This set hole 6
0a has a diameter at which the work 17 is loosely fitted. A rotating plate rotating motor 61 is provided on a slide table 53, and a gear 62 that meshes with a gear 59 of a rotating plate 57 is fixed to a motor shaft of the motor 61. Then, by the rotation of the motor 61, the rotating plate 57 is
Rotates. The inner diameter of the outer peripheral frame 57 a has a diameter such that the upper rotary grindstone 16 descending offset with respect to the rotary plate 57 can approach the work supporting plate 60.

As shown in FIG. 4, a notch or orientation flat (orientation flat) or the like serving as a reference for the crystal orientation of the work 17 which is an unground wafer which has been cut from the ingot is formed in the set hole 60a of the work support plate 60. A work drive unit 60b protruding toward the inner peripheral side so as to engage with the portion 17a is provided. Notch 1 of this work 17
The shape of 7a is a shape having a V-groove-shaped notch as in the present embodiment or an orientation flat that cuts a circular arc on the outer periphery of the work as an edge, and the driving portion 60b is a shape that substantially complements the cutout portion 17a of the work. However, the notch 1 of the work 17
7a may be separately provided on the work 17 in order to drive the work 17 at a position other than the position for knowing the crystal orientation.

Although the work set hole 60a is a circle in this example, the shape is not limited to a circle, and any shape may be used as long as the position of the work 17 is determined. 17 may be in contact with the outer periphery.

Next, the operation of the double-sided surface grinding machine configured as described above will be described.

Now, in this double-sided surface grinding machine, when grinding is performed, the work 17 is
The upper and lower rotary grindstones 15 and 16 are inserted and disposed between the upper and lower rotary grindstones 15 and 16 while the upper and lower grindstone rotary elevating mechanisms 12 and 13 are loosely fitted to the work support plate 60. In this state, the upper and lower rotary grindstones 15, 16 are rotated at a high speed while the upper and lower grindstone rotary elevating mechanisms 12, 13 are rotated at a high speed, the rotary plate rotating motor 61 is driven to rotate at a low speed, and the work supporting plate 60 serves as a rotary drive means. Gear 6
The work 17 held by the set holes 60a is rotated through the rotation of the workpieces 2 and 59. Then, the upper rotary grindstone 16 of the upper grindstone rotary elevating mechanism 13 descends and approaches the work 17, and the grinding action surfaces 15 a,
Both surfaces of the work 17 are simultaneously ground by 16a.

FIG. 7 is a front view showing a grinding operation surface of the grinding tool, and FIG. 8 is a longitudinal sectional view of the grinding tool including the center of FIG. In the present embodiment, the same members are used for the rotating grindstones (grinding tools) 15 and 16 described above. Here, the whole of the grinding tool is represented by reference numeral 1.

This grinding tool 1 is provided with a diamond grindstone 3 as a rotary grindstone slightly smaller than the diameter of the baseplate 2 and concentric with the grindstone shaft on the end surface of the baseplate 2 made of an iron disk. The diamond grindstone 3 is arranged in an annular shape with a width.

The diamond grindstone 3 is obtained by hardening diamond abrasive grains with a binder and fixing it to the base plate 2.

The grinding surface 3a of the diamond wheel 3 is on the same plane perpendicular to the wheel axis. A cylindrical concave fitting portion 2a is fitted on the rear surface of the base plate 2 to a convex fitting portion 6a of a grindstone holder 6 having the same diameter as the base plate 2 (used in place of the reference numerals 29 and 43). Then, the back surface of the base plate 2 and the front surface of the grindstone holder 6 are brought into close contact with each other, and a bolt 7 inserted through a bolt hole of the base plate 2 is screwed into the grindstone holder 6 and fixed.

FIG. 7 shows a diamond grindstone 3 and a work 17.
Dimensions and positional relationship are shown. When the work 17 is set in the work set hole 60a, the work set hole 60a
The center of a and the center of the work 17 coincide. The center 0G of the diamond grindstone 3 is offset from the work center 0W so that the diamond grindstone 3 passes on the work center 0W.
doing. Assuming that the average diameter centered on 0 G through the bisecting point of the grinding wheel surface 3a in the radial direction of the diamond grinding wheel 3 is called a grinding wheel average diameter, in this example, the grinding wheel average diameter is one half of the diameter of the work 17. Has become. The average diameter of the grindstone is a diameter obtained by subtracting the radial width of the grinding surface 3a from one half of the diameter of the work 17, that is, a range in which the outer diameter of the grindstone of the diamond grindstone 3 is a half of the diameter of the work 17. In theory, it is desirable that the outer diameter of the grindstone is larger than one half of the diameter of the work 17 so that the entire surface of the work 17 can be ground but the work surface that is not ground in practice does not occur.

On the other hand, since the upper grindstone 16 must enter the outer peripheral frame 57a of the rotary plate 57, the average diameter of the grindstone is Dg, the diameter of the grindstone holder (or the base plate 2) 6 is Dp, and the inner diameter of the outer peripheral frame 57a is Is Df, Dg + Dp <Df. Therefore, the work 17 can be ground by the diamond grindstone 3 even if the grindstone diameter Dg is larger than one half of the diameter of the work 17. However, if the diameter Dp of the grindstone holder 6 is large, the diameter of the outer peripheral frame 57 becomes large. . Also, the offset amount e between the workpiece center 0W and the grinding wheel center 0G increases. Accordingly, if the average diameter Dg of the grindstone is set to approximately one half of the diameter of the work 17, it is effective to reduce the size of the device around the grindstone.

As shown in FIGS. 2 and 7, upper and lower work rests 71, 7 for holding both surfaces of the work 17 protruding from the outer peripheral side of the grindstone at the contact surface between the work 7 and the upper and lower grindstones 15, 16 are shown.
2 are provided. The lower work rest 71 is fixed on the lower frame 11 (FIG. 2) or is disposed on an arm 74 fixed to the vertical output shaft 73a of a hydraulically operated rotary actuator 73 fixed to the lower frame 11. (FIG. 7).

As shown in FIG. 17 which is a partially enlarged view of FIG.
Distance piece 76 on base 75 fixed on top
A lower hydrostatic slide 77 is provided via. FIG.
As shown in FIG.
Reference numeral 7a designates a straight line connecting the rotary plate center 0W and the grinding wheel center 0G as a symmetrical line with a small gap so as to face the surface of the work 17 protruding from the contact portion between the grinding tool 1 and the work 17 on both sides of this diameter. Has been established. Lower hydrostatic slide 7
A pocket (not shown) is provided on the slide surface 77a of the slide 7, and a passage for the pressure fluid supplied toward the pocket is provided. However, since a static pressure fluid film is formed even without a pocket, a case without a pocket can be adopted. That is, the pressure fluid inlet 75a of the base 75, the fluid passage 75
b, a fluid passage 77b of a lower hydrostatic slide 77 fitted into the base 75 via a sealing ring 78, and a fluid passage 77b between the fluid passage 77b and a pocket (not shown) provided on the slide surface 77a. The communicating orifice 77c is provided continuously, and the pressure fluid supplied from the pressure fluid inlet 75a flows between the slide surface 77a of the lower hydrostatic slide 77 and the opposing surface of the lower surface of the work 17. The pressurized fluid supplied to the slide surface 77a and the lower surface of the work 17 flows back from the reflux port of the slide surface 77a facing the lower surface of the work 17 outside the pocket (not shown). It should be noted that a hybrid fluid pressure slide utilizing the static pressure and the dynamic pressure by eliminating the reflux port and allowing the pressure fluid supplied between the work 17 and the slide surface 77a to flow out of the gap between the work 17 and the slide surface 77a into the external space. Is also good.

The upper work rest 72 has an upper hydrostatic slide body 81, and comprises a cylinder body 79a, a cylinder bush 79b, and a cylinder lid 79g, which constitute a hydraulic cylinder 79, in which an upper part integrated with a piston 81e is provided. A hydrostatic slide main body 81 is provided to be vertically movable. The supply of the pressure fluid to the upper fluid static pressure slide body 81 is performed by a pressure fluid inlet 79 provided in the cylinder body 79a.
c, a hole 79d of the cylinder bush 79b, an outer peripheral groove 81a of the upper hydrostatic slide main body 81, a fluid passage 81b provided in the upper hydrostatic slide main body 81, a slide surface of the work 17 and a surface of the upper hydrostatic slide main body 81. The pressure is supplied through an orifice 81c which communicates with a pocket provided in the pocket 81d and the fluid passage 81b. Note that a hybrid fluid pressure slide may be used.

The upper fluid static pressure slide body 81 is controlled by selectively flowing out and in from the pressure fluid ports 79e and 79f to both sides of the piston 81e, or by not supplying the pressure fluid together. That is, when the pressure fluid flows into the lower cylinder chamber and the upper cylinder chamber is made non-pressurized, the upper hydrostatic slide body 81 rises, and conversely, when the pressure fluid flows into the upper cylinder chamber and the lower cylinder chamber is depressurized, the upper The hydrostatic slide body 81 descends. It is appropriate to control the speed by bleeding off the non-pressure side. When both cylinder chambers are not pressurized, the upper hydrostatic slide main body 81 tends to descend by its own weight.

The upper work rest 72 having the upper hydrostatic slide constructed as above is connected to the upper frame 111.
Or fixed to the upper shaft support cylinder 38. Alternatively, it can be made to be able to move up and down by an independent lifting device (not shown). Further, similarly to the lower work rest 71, the arm may be movable along the work 17 by using an arm, and a position where the surface of the work 17 is held and a position where the work 17 is retracted out of the work 17 may be set.

The above-mentioned pressure fluid may be a gas or a liquid, but the gas is compressed air, the fluid is oil,
A grinding fluid or the like is used.

The operation of the above configuration will be described. The slide surface 77a of the lower hydrostatic slide 77 is located at a position where the lower surface of the work 17 is held. The upper hydrostatic slide main body 81 is retracted from a position for holding the upper surface of the work 17. This retreat position needs at least a position where the upper hydrostatic slide body 81 has risen with respect to the cylinder 79. However, if the retreat position is rising together with the upper shaft support 38 as described above, the upper shaft support After lowering the upper grinding wheel 16 by lowering 38, the upper hydrostatic slide main body 81 is set to the lower position with respect to the cylinder 79. The slide table 53 is moved while the upper rotary grindstone 16 is raised, and the center 0W of the work set hole 60a is offset from the center 0G of the grinding tool 1 to be positioned. This offset e is the average radius of the diamond grindstone 3. The workpiece center 0 W must necessarily overlap the diamond grindstone 3. At this point, the lower rotating grindstone 15 is raised to approach the lower surface of the work support plate 60, and the work 17 is moved to the work drive unit 6 in which the notch 17a of the work 17 projects into the work setting hole 60a.
The workpiece 17 is fitted into the workpiece setting hole 60a by being engaged with the workpiece 0b, and is placed on the lower rotating grindstone 15. As a result, the upper and lower surfaces of the work 17 project upward and downward, respectively, from the upper and lower surfaces of the work support plate 60. Here, the upper rotating grindstone 16 descends and approaches the work 17. Then, the slide surface 81d of the upper hydrostatic slide main body 81 moves from the retracted position toward the upper surface of the work 17. At this time, the slide surface 81d is set on the upper surface of the work 17 at a position where the upper hydrostatic slide body 81 does not descend to the lower limit position with respect to the cylinder 79.

Here, the pressurized fluid is supplied to the upper and lower fluid static pressure slides of the upper and lower work rests 71, 72, respectively, and the portions 17b protruding from the opposing surfaces of the work 17 with the grindstones 15, 16 become the upper and lower fluid static slides. It is held by a pressure slide. This work 17 is held by the lower hydrostatic slide 77
The lower surface of the work 17 is determined with respect to the slide surface 77a, and the upper hydrostatic slide main body 81 is mounted on the upper surface of the work 17. In this case, only the own weight of the upper fluid static pressure slide body 81 is directed toward the workpiece 17 so that an appropriate static pressure fluid film is generated between the slide surface 81d of the upper fluid static pressure slide body 81 and the surface of the workpiece 17. Pressurization or pressurization is performed by the cylinder 79.
The pressure medium of the cylinder 79 can employ any of gas and liquid. When the grindstone driving motors 34 and 48 and the work plate rotating motor 61 are energized, the upper and lower rotating grindstones 15 and 16 and the work 17 are rotated, respectively. Here, when the upper rotating grindstone 16 is lowered and cut into the work 17, the diamond grindstone 3 grinds both surfaces of the work 17 respectively. At the time of this grinding, portions protruding from the grinding wheel contact surface other than where the grinding action surface 3a of the diamond grinding wheel 3 of the work 17 is acting (an arc band passing through the center of the work 17) are work rests 71 and 72 from both sides. Hold.

When the work 17 is finished, the upper grindstone 16
The upper hydrostatic slide body 81 is raised, and the lower grindstone 15 is raised.
17b of the work 17 protruding from the outer peripheral side
(See FIG. 7) and lift the work 17 into the set hole 60a.
And remove the work 17. As described above, the upper fluid static pressure slide main body 81 is balanced with the load capacity of the static pressure fluid film between the static pressure slide surface 81d and the work 17 by the weight of itself or the pressurization of the cylinder 79, so that the thermal deformation of the machine body or the like is achieved. And the work 17 can always be held accurately.

In the above description, the work 17 has a wafer diameter of 200 mm and a work rotation speed of 10 r. p. m, the outer diameter of the diamond grindstone 3 is 160 m, the inner diameter is 130 mm, and the upper and lower rotating grindstones 15 and 16 are rotated.
0-3000r. p. After grinding with m, TTV 0.3μ
m, the grinding time was 2 minutes.

In the above description, the upper and lower work rests 71,
Although both surfaces of the work 17 are held at 72, only one surface of the work 17 may be held by one of the work rests. Therefore, in the case of holding the work 17 only on one side of the work 17 with the work rest, it is sufficient to provide any one of the upper and lower work rests 71 and 72.

(Embodiment 2) FIGS. 9 and 10 show an example of a grinding tool 1 using a diamond impregnated grindstone. On the surface of the base plate 2, a diamond impregnating grindstone 8 is provided in such a manner that a plurality of concentric circles are alternately provided in radial directions in the same direction. Work 1 for work 17
Grinding is performed so that the center of 7 is on the outer peripheral side of the grinding tool 1. As in the case of the cup grindstone, the grindstone diameter is slightly larger than half the diameter of the work 17.

(Embodiment 3) If the main purpose is to grind one side of the work 17, the above-mentioned double-headed grinder is used to rotate the lower rotating grindstone 15, rotate it slowly, or work with the lower rotating grindstone. 15 may be changed to a member having a small or no grinding effect on the workpiece 17.

(Embodiment 4) In the case where one side of the work 17 is to be ground, a single-head surface grinder having a grindstone having an end surface as a grinding surface may be used. FIG. 11 shows such a single-headed grinding machine, in which the lower frame 11 has no lower wheel-related members, and only the guide rail 52 and the work supporting member 14 are provided on the lower frame 11. In this case,
A hydrostatic slide 83 may be provided on the upper surface of the lower frame 11 as shown in FIG. 15, and the above-mentioned work support plate 60 may be provided so as to approach this upper surface, and as shown in FIG. May be provided with a bottom 60c. In the case of FIG. 14, the depth of the work set hole 60 a is naturally smaller than the thickness of the work 17.

The hydrostatic slide 83 is provided concentrically with the work 17. Therefore, the entire surface of the work 17 is supported at a fixed position, and since the work 17 does not come into contact with a solid, the anti-ground surface of the work 17 is not damaged. In addition, the flat surface of the hydrostatic slide 83 supporting the work 17 has good flatness over the entire surface and only supports the work 17, so that there is no decrease in accuracy due to restoration after processing such as suction by a vacuum chuck. .

In the above description, the hydrostatic pressure slide 83 faces the upper work rest 72 except for the portion facing the upper grindstone 16 with the work 17 therebetween. Therefore, the work 17 is pressurized substantially over the entire surface by the upper hydrostatic slide body 81 and the upper grindstone 16, so that the work 17 does not warp.

The bottom 6 is set in the work set hole 60a of the rotating plate 57.
By providing 0c, the bottom surface of the work 17 can be easily supported. Also in this case, the work 17 is pressurized by the upper hydrostatic slide main body 81 and the upper grindstone 16, so that the work 17
Does not warp. In the above description, the lower surface side of the work 17 is supported by a member (for example, a hydrostatic bearing) having a flat surface having the same diameter as the upper grindstone 16, and the upper grindstone 16 and a flat surface having the same diameter as the upper grindstone 16 below the upper grindstone 16. The part of the work 17 protruding from the member having the
It may be held at 72.

(Fifth Embodiment) FIG. 12 shows a fifth embodiment. Since the upper and lower grindstones 15 and 16 are worn by grinding, the upper and lower grindstones 15 and 16 are required to make the work 17 have a constant thickness.
When the wear amount reaches a predetermined amount, it is necessary to drive in the wear amount (to advance the grindstones 15 and 16).

In the figure, a turning shaft 84 parallel to the grinding wheel shafts 28 and 42 is connected to a rotary drive source and is supported. The root of an arm 85 is fixed to the turning shaft 84. Arm 8
The position sensor 86 attached to the tip of the upper and lower wheels 5,
Grinding action surface 1 of whetstones 15, 16 in contact with or in proximity to
The positions of 5a and 16a can be detected.

As shown in FIG. 12, the upper grindstone 15 is mainly raised, and the grinding action surfaces 15 of the unworn grindstones 15 and 16 are formed.
The positions detected by the position sensor 86 by contacting or approaching the position sensors a and 16a with the position sensor 86 are stored in a storage device (not shown). Then, the arm 85 is rotated and the position sensor 86
After the workpieces 17 are retracted from the grindstones 15 and 16 and the work 17 is ground, the grindstones 15 and 16 are retracted to the state shown in FIG. 12 and the positions of the grinding action surfaces 15a and 16a are detected in the same manner as described above. At the time of detecting this position, the amount of wear of the grindstones 15 and 16 is determined by an encoder attached to the elevating motors 25 and 40, so that the grinding action surfaces 15a,
16a is driven by the control device to finish the thickness of the work 17 uniformly. As the position sensor 86, an air micro, a differential truss, an AE sensor or the like is used.

(Sixth Embodiment) FIG. 16 shows a sixth embodiment. The sixth embodiment is characterized in that the lower work rest 71 is supported, and other configurations are the same as those of the first embodiment.

A disk 91 concentric with the grinding wheel shaft 28 is fixed to the lower grinding wheel stand 20. A radial bearing 92 is fixed to the disc 91 concentrically. A hydrostatic slide 93 is provided so as to sandwich the outer periphery of the disk 91 from above and below, and the upper and lower surfaces of the disk 91 support the hydrostatic slide 93. The hydrostatic slide 93 has an annular upper slide 93a and a lower slide 93b fixed to each other via a distance piece 93c. Upper slide 93
“a” is rotatably fitted to the radial bearing 92.

The hydrostatic slide 93 serves as an annular table, and a lower hydrostatic slide, ie, a lower work rest 71 is formed on the upper slide 93a of the annular table. A part of the supply path of the pressure fluid to the lower hydrostatic slide is provided in the upper slide 93a. The hydrostatic slide 93 is rotated by a driving device (not shown), but the rotation angle is within 90 degrees. The supply of the pressurized fluid to the hydrostatic slide 93 is performed using a flexible tube (not shown).

In the state shown in FIG.
Reference numerals 1 and 72 are at opposing positions, and hold the work 17 and grind the work 17 with the grindstones 15 and 16. When the work 17 is detached from the machine, if the hydrostatic slide 93 is turned by 90 degrees from the position shown in FIG. 16, the lower work rest 71 which has been below the work 17 becomes a space. By raising the pressure slide body 81, the work 17 can be easily attached and detached. According to this embodiment, via the disk 91 and the hydrostatic slide 93,
Since the lower work rest 71 follows the vertical movement of the lower grindstone table 20, the work 1 of the lower work rest 71 is
The height of the slide surface 77a for holding the workpiece 7 is at a position where the workpiece 17 being ground can always be held in a good horizontal position.
Moreover, a stable holding state can be obtained by absorbing thermal deformation and vibration.

(Seventh Embodiment) FIGS. 18 and 19 show a slide surface of a hydrostatic slide used in a seventh embodiment.
In this embodiment, the work 17 is supported only by the lower work rest 71 without using the upper work rest 72.

As described above, the point that the portion 17b of the work 17 protruding from the grindstone is supported at two locations on one side by hydrostatic bearings is also the same in this embodiment.

In the figure, the lower static pressure slide 77 has a circular slide surface 77a as in the previous embodiment. A suction orifice 77 is provided at the center of the slide surface 77a.
The orifice 77c for discharge is disposed by arranging three circles around the orifice 77d for suction with d.

The pressure fluid discharged from the discharge orifice 77c enters the space between the discharge orifice 77c and the lower surface of the work 17 to form a static pressure fluid layer.

In this fluid static pressure layer, the pressure fluid flows toward the suction orifice 77d that is being sucked. The negative pressure and the orifice diameter in the suction orifice 77d are provided so as to reduce the thickness of the fluid static pressure layer.

Since the work 17 is thus floated at a position balanced with the weight of the work 17, the work 17 is caused to float at the periphery of the discharge-side orifice 77c from which the pressurized fluid is blown out. Since the work 17 is to be drawn in at the center of the suction orifice 77d, the work 17 and the slide surface 77a are balanced in a small gap state, so that the rigidity for supporting the work 17 can be improved.

According to this embodiment, the range in which the suction force of the suction orifice 77d is applied to the work 17 is small, so that the work 17 is not deformed and can hold the work 17 with rigidity.

In the embodiment of the present invention, a grindstone having a grindstone diameter of approximately one half of the diameter of the work is placed so that the grinding center passes through the rotation center of the work, and a grinding surface is provided on the outer peripheral side of the work. As a result, the inner diameter of the outer peripheral frame 57a of the rotating plate 57 that supports and rotates the work is small, and the rotating plate 57 is small, so that the work supporting member 14 is small.

In the embodiment of the present invention, when a portion of the work that protrudes from the outside of the grinding action surface of the grindstone is held by the work rest, the above-described work wheel having a diameter approximately half that of the work is used. The problem of how to maintain the position of a workpiece is solved.

In the embodiment of the present invention, as described above, a work supporting plate thinner than a wafer having a work set hole having a driving part projected into a notch provided for indicating the crystal orientation of the wafer is rotated. Since the grindstones are simultaneously applied to the upper and lower surfaces of the wafer for grinding, there is an effect that the wafer is reliably fed in rotation, the grinding action acts on the entire surface of the wafer and both surfaces are simultaneously ground. And because of the grinding, good surface roughness can be secured in a short time, and when the wafer is sucked by the vacuum chuck, the wafer is pulled into the suction surface of the vacuum chuck, and is flattened. When processing is removed from the vacuum chuck, the shape is restored by the elasticity and the shape accuracy is deteriorated. However, according to this embodiment, since the work is not flattened to support the work, the shape accuracy is good.

Also in the case of single-side grinding, as described above, the wafer is fitted in a set of a work support plate, and the driving unit is fitted in a notch for observing the orientation of the wafer crystal, and is forcedly rotated on the wafer. Since it gives the feed, the shape accuracy becomes good in addition to the good surface roughness.

Although the vertical double-sided surface grinder and the vertical single-sided surface grinder have been described as the grinding machines in the embodiment, a horizontal double-sided surface grinding machine or a horizontal single-sided surface grinding machine may be used.

[0101]

According to the wafer processing method of the present invention, the position of the work portion protruding from the grindstone is regulated by the work rest. Therefore, even when the grindstone diameter is set to approximately one half of the work diameter, it is stable. Grinding is possible. And the support member of a work can be made small.

By using the hydrostatic slide as the work rest, the wafer is not damaged by the work rest, and the work rest is suppressed, so that the grinding is stably performed.

[Brief description of the drawings]

FIG. 1 is a front view showing an embodiment of a double-ended surface grinder according to the present invention.

FIG. 2 is a longitudinal sectional view of a main part of a lower frame portion.

FIG. 3 is a longitudinal sectional view of a main part of an upper frame portion.

FIG. 4 is a plan view of a work supporting member.

FIG. 5 is a longitudinal sectional view showing a slide table unit.

FIG. 6 is a perspective view of the same.

FIG. 7 is a plan view showing a relationship between a grinding tool, a work, and a work rest.

FIG. 8 is a longitudinal sectional view of the grinding tool of FIG. 7;

FIG. 9 is a front view showing another example of the grinding tool.

FIG. 10 is a longitudinal sectional view of FIG. 9;

FIG. 11 is a front view showing an embodiment of the single-head grinding machine of the present invention.

FIG. 12 is a plan view schematically showing a method of detecting a grinding wheel wear of a grinding wheel.

FIG. 13 is a longitudinal sectional view of a work supporting member.

FIG. 14 is a longitudinal sectional view of a work supporting member.

FIG. 15 is a longitudinal sectional view of a work supporting member.

FIG. 16 is a longitudinal sectional view showing a moving member of a work rest according to another embodiment.

FIG. 17 is a partially enlarged view of FIG. 2;

18 is a sectional view taken along the line AA in FIG.

FIG. 19 is a plan view of a hydrostatic slide according to a seventh embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Grinding tool 2 ... Base plate 2a ... Concave fitting part 3 ... Diamond grindstone 3a ... Grinding operation surface 6 ... Grindstone holder 6a ... Convex fitting part 7 ... Bolt 8 ... Diamond impregnating grindstone 11 ... Lower frame 12 ... Lower part Grinding wheel rotating / lifting mechanism 13 ... Upper grinding wheel rotating / lifting mechanism 14 ... Work support member 15 ... Lower grinding stone 15a ... Grinding working surface 16 ... Upper grinding stone 16a ... Grinding working surface 17 ... Work (wafer) 17a ... Notch 17b ... Part 20 ... Grinding stone Table 21 ... Guide 22 ... Lower wheel head moving motor 23 ... Ball screw 23a ... Ball nut 24 ... Lower shaft support 24a ... Guide part 24b ... Bracket 25 ... Lower wheel head lift motor 26 ... Rotation transmission mechanism 27 ... Ball screw 28 ... Lower wheel shaft 29. Wheel holder 34. Wheel drive motor 38. Upper shaft support 38 a. Bracket 39. 0 ... Moving motor 41 ... Ball screw 41a ... Ball nut 42 ... Upper grindstone shaft 43 ... Whetstone holder 48 ... Gritstone driving motor 52 ... Support table 53 ... Slide table 54 ... Guide rail 55 ... Slide table moving motor 56 ... Ball screw 56a: Ball nut 57: Rotating plate 57a: Outer frame 58: Guide roller 59: Gear 60: Work support plate 60a: Set hole 60b: Work drive unit 60c: Bottom 61: Rotating plate rotation motor 62: Gear 71: Lower work Rest 72 Upper work rest 73 Rotary actuator 73a Output shaft 74 Arm 75 Base 75a Pressure fluid inlet 75b Fluid passage 76 Distance piece 77 Lower static pressure slide 77a Slide surface 7
7b ... fluid passage 77c ... orifice 77d ... suction orifice 78 ... sealing ring 79 ... cylinder 79a ... cylinder body 79b ... cylinder bush 79c ... pressure fluid inlet 79d ... hole
79e, 79f: Pressure fluid inlet / outlet port 79g: Cylinder lid 81: Upper fluid static pressure slide body 81a: Outer peripheral groove 8
1b Fluid passage 81c Orifice 81d Sliding surface 81e Piston 83 Fluid static pressure slide 84 Rotating shaft 85 Arm 86 Position sensor 91 Disk 92 Radial bearing 93 Fluid static slide 93a Lower slide 93
b: Upper slide 93c: Distance piece 111: Upper frame

Continued on the front page (72) Inventor Toyohashi Wada 100 Fukuno-cho, Higashi-Tonami-gun, Toyama Prefecture Inside of Hirai Toyama Toyama Plant

Claims (39)

[Claims] 1. A method for processing a wafer after cutting from an ingot, comprising: a work supporting member that holds the wafer and rotates the wafer;
Prepare a double-sided surface grinder that grinds the grinding wheel end face with the grinding wheel end faces facing each other, and a work rest that holds the surface of the wafer protruding from the outer circumference of the grinding stone at the contact portion between the wafer and the grinding wheel end face, and the wafer supporting member prepares the wafer. A wafer is held by a work rest and a grindstone is applied to both surfaces of the wafer so that the center of the wafer passes through a grinding wheel grinding action surface to perform grinding. 2. The method according to claim 1, wherein the work rest acts on both surfaces of the wafer. 3. The wafer processing method according to claim 1, wherein the work rest acts on one side of the wafer. 4. The wafer processing method according to claim 1, wherein both sides of said whetstone are simultaneously ground using a whetstone having a grinding action. 5. The method according to claim 1, wherein one of the whetstones uses a grindstone having a grinding action, and the other whetstone uses a whetstone having a smaller grinding action than the grinding wheel having a grinding action. 2. The method for processing a wafer according to 1. 6. The method according to claim 1, wherein a cup grindstone is used as the grindstone. 7. The grinding wheel according to claim 1, wherein a whetstone having a diameter approximately half of the diameter of the wafer is used.
5. A method for processing a wafer according to any one of the above. 8. A double-sided surface grinder in which a grindstone end face is disposed to face a surface of a disk-shaped work with the grindstone end face, wherein the work is held and the work is rotated about a center parallel to the grindstone axis. A double-sided surface grinder comprising: a work supporting member; a grindstone; and a work rest for holding a surface of the work protruding from the grindstone when the grindstone is applied to the surface of the work. 9. The double-sided surface grinding machine according to claim 8, wherein the work rest holds both surfaces of the work. 10. The double-sided surface grinding machine according to claim 8, wherein the work rest holds one side of the work. 11. The double-sided surface grinding machine according to claim 8, wherein the work rest forms a hydrostatic bearing between the work rest and the work surface. 12. The moving member according to claim 8, wherein a work rest at least on one side of the work rest is provided at a position for holding the work and a retracted position for not holding the work. 12. The double-sided surface grinder according to any one of items 1 to 11. 13. The double-headed grinding machine according to claim 12, wherein the moving member is a grindstone head. 14. The double-sided surface grinding machine according to claim 12, wherein the moving member is an arm member supported by a pivot parallel to a grindstone axis and having a work rest attached to a tip thereof. 15. The double-sided surface grinding machine according to claim 12, wherein the moving member is an annular table rotatably supported at the same center as a grindstone shaft with respect to a grindstone stand. 16. The double-sided surface grinding machine according to claim 15, wherein the annular table is supported by a hydrostatic slide. 17. A method of processing a wafer after cutting from an ingot, comprising: a work supporting member that holds the wafer and rotates the wafer;
Prepare a single-head surface grinding machine that performs grinding on the grinding wheel end face, and a work rest that holds the surface of the wafer that protrudes from the grinding wheel outer peripheral side of the contact portion between the wafer and the grinding wheel end face, while rotating and driving the wafer with the workpiece support member A wafer processing method comprising: holding a surface of a wafer by a work rest; and performing grinding by applying a grindstone to the surface of the wafer so that a grinding wheel grinding surface passes the center of the wafer. 18. The method according to claim 17, wherein a cup grindstone is used as the grindstone. 19. The method according to claim 17, wherein the work rest is used by acting on a surface of the wafer which is in contact with the grinding surface of the grindstone, and the surface of the wafer which is not ground is supported by a work supporting member. The method for processing a wafer according to the above. 20. A single-head surface grinding machine for processing a plate surface of a disk-shaped work with an end surface of a grinding wheel, a work supporting member for holding the work and rotating the work around a center parallel to a grinding wheel axis, a grinding wheel, A single-head surface grinding machine, comprising: a work rest for holding a surface of a work protruding from the grindstone when the grindstone acts on the surface of the work. 21. The single-head surface grinding machine according to claim 20, wherein the work rest is provided on both sides of the work. 22. The single-head surface grinding machine according to claim 20, wherein the work rest is provided on one surface side of the work. 23. The single-head surface grinding machine according to claim 20, wherein the work rest forms a hydrostatic slide between the work rest and the work surface. 24. The apparatus according to claim 20, wherein the work rest is disposed on the moving member so as to take a position for holding the work and a retracted position for not holding the work. The single-head surface grinder described. 25. The single-head surface grinding machine according to claim 24, wherein the moving member is a grindstone head. 26. The single-head surface grinding machine according to claim 24, wherein the moving member is an arm member supported by a pivot parallel to a grindstone axis and having a work rest attached to a tip thereof. 27. The single-head surface grinding machine according to claim 24, wherein the moving member is an annular table rotatably supported on the grindstone table at the same center as the grindstone axis. 28. The single-head surface grinding machine according to claim 27, wherein the annular table is supported by a hydrostatic slide. 29. A double-headed work rest for rotating a disc-shaped work to cut a grinding action surface on both sides or a part of one side of the work at an end surface of a grindstone to perform grinding. A work rest, comprising: a work holding member for holding a plate surface of a work by approaching to both sides or one side of the work via a contact or pressure medium. 30. A work holding member of the work rest having a gap on a surface facing the work and having a fluid passage for supplying a pressure medium to the gap, forming a hydrostatic slide between the work and the work holding member. 30. The method of claim 29, wherein
Workrest as described in. 31. The workrest according to claim 29, wherein the pressure medium is a gas. 32. The work rest according to claim 29, wherein the pressure medium is a liquid. 33. The apparatus according to claim 29, wherein the work holding member is provided on a moving member that takes a position for holding a surface of the work and a position retracted from the work. Workrest as described in. 34. The moving member, which is a movable member that moves the work holding member in a direction parallel to the plate surface of the work, and takes a position where the work holding member faces the work and a position where the work holding member does not face the work. The workrest according to claim 33, wherein: 35. The moving member according to claim 33, wherein the moving member is located at a position in contact with or approaching the plate surface of the work and at a position facing the plate surface of the work and away from the work. Workrest as described in. 36. The workrest according to claim 35, wherein the moving member also serves as a grinding wheel base of a double-sided surface grinding machine. 37. The work according to claim 34, wherein the moving member is an arm member rotatably supported by a pivot parallel to a grindstone axis of a double-sided surface grinder and having a work holding member at a tip end. Rest. 38. The workrest according to claim 34, wherein the moving member is provided on a grindstone table so as to be rotatable around a grindstone axis of the double-sided surface grinder. 39. The moving member comprises a hydrostatic slide between the moving member and a grinding wheel head.
Workrest as described in.