JP2005288558A - Method for surface polishing object to be processed - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent or reduce face sagging of an object to be processed in a method for surface polishing the object. <P>SOLUTION: In this method for surface polishing the object 1 to be processed, a step for providing a face sagging protective member 2 having thickness ≥0.8 times as much as target thickness of the object 1, and a step for surface polishing the object 1 in a state in which the face sagging protective member 2 is arranged adjacent or close to an edge part of the object 1 are included. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a surface polishing method for an object to be processed, and more particularly to a method for surface polishing an object to be processed in manufacturing a recording medium substrate, a photomask, a device, or the like for magnetic recording.

The increase in recording density (surface density) of magnetic recording is very rapid, and during the last 10 years, the rapid increase of 50% to 200% per annum has progressed continuously. 70 Gbit / inch ² (about 10.9 Gbit / cm ² ) products were shipped at the mass production level, and the surface recording density of 160 Gbit / inch ² (about 24.8 Gbit / cm ² ) doubled was reported at the laboratory level. Yes. The surface recording density at the mass production level corresponds to 80 Gbytes per platter in a 3.5 inch HDD, and corresponds to 40 Gbytes per platter in a 2.5 inch HDD. Recording density is expected to continue to improve. Furthermore, it is considered that the diameter of the magnetic recording substrate will be reduced in the future as the recording density increases.

  In order to reduce the diameter and increase the recording density per unit area, it is necessary to lower the glide height of the magnetic recording head. Specifically, the required glide height is conventionally about 30 nm, but is expected to be 10 nm or less in the future. Of course, the lowering of the glide height makes it essential to improve the flatness of the substrate surface. In that case, a decrease in the recordable area due to the surface fringing of the outer edge of the substrate becomes a problem.

  Usually, in the case of a 2.5-inch substrate, the outer edge portion is about 1 to 2 mm, and it is considered that there are cases where it cannot be used as a recording surface. When simply calculated, 7 to 13% of the substrate area cannot be used as a recording surface due to the surface deviation. In the case of the 1.89 inch size having a small diameter, the area that cannot be used as a recording surface due to the influence of the surface is 9 to 17% of the substrate area, and the influence of the surface is increased as the diameter is decreased. In the future, the recording area will become smaller as the diameter is reduced, and it is considered that the loss of the recording area due to surface fringing becomes a serious problem.

  Also, in the photomask, if there is a fringe, the image will be blurred, and it is considered that the drooping will become a major problem in the further miniaturization of photomasks in the future.

Conventionally, to prevent the sagging, a groove is formed in the polishing cloth, or the outer edge portion protrudes from the polishing cloth during the processing (overlap) to prevent the sagging. In addition, surface sagging has been prevented by polishing with a polishing cloth having high hardness. However, when the polishing cloth becomes hard, the surface drooping is improved to some extent, but there is a problem that scratches are easily generated on the polished substrate surface.
JP 5-326468 (Kawasaki Steel) Si wafer surface drooping improvement

  In view of the above, an object of the present invention is to prevent or reduce the sagging of the object to be processed in a method of performing surface polishing on the object to be processed.

  According to one aspect of the present invention, there is provided a method for subjecting a workpiece to surface polishing, the step of providing a surface protection member having a thickness of 0.8 times or more the target thickness of the workpiece, A surface polishing method for an object to be processed is provided, including a step of surface polishing the object to be processed in a state in which a drooping protection member is disposed adjacent to or close to an edge of the object to be processed.

  Further, according to another aspect of the present invention, there is provided a method for subjecting a workpiece to surface polishing, the step of arranging a surface protection member adjacent to or close to an edge of the workpiece, A step of arranging the surface protection member such that the surface of the surface protection member has substantially the same height as the target thickness of the object to be processed; There is provided a surface polishing processing method for an object to be processed, which includes a step of surface polishing the object to be processed in a state of being adjacent to or adjacent to an edge.

  Moreover, according to the other side surface of this invention, the to-be-processed object processed by the said method obtained by the said method is provided.

  According to another aspect of the present invention, when the object to be processed is subjected to surface polishing, it is disposed adjacent to or close to the edge of the object to be processed, thereby protecting the surface of the object to be processed. There is provided a surface drooping protection member having a thickness of 0.8 times or more the target thickness of the workpiece.

  As will be described in detail below, according to the present invention, it is possible to prevent or reduce the sagging of the object to be processed in the method for subjecting the object to the surface polishing. For example, in the case where the planar polishing method according to the present invention is applied to the manufacture of a magnetic recording medium, the sagging of the substrate for the magnetic recording medium is improved, and the loss of the recording area of the substrate surface due to the sagging is minimized. can do.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. However, the embodiments described below do not limit the present invention.

  As described above, according to one aspect of the present invention, there is provided a surface drooping protection member having a thickness of 0.8 times or more of a target thickness of the object to be processed, which is a method for subjecting the object to a surface polishing. There is provided a surface polishing processing method for an object to be processed, comprising: a step; and a surface polishing of the object to be processed in a state where the surface protection member is disposed adjacent to or close to an edge of the object to be processed Is done.

  The surface polishing method according to the present invention can be applied to the surface polishing of any object to be processed, and is particularly preferably applied to the surface polishing of an object for which it is desired to prevent sagging. More specifically, the present invention is preferably applied to planar polishing of a workpiece such as a magnetic recording medium substrate, a photomask substrate, or a device substrate.

  The shape of the object to be processed may be any shape such as a circular shape, a pseudo-circular shape, an annular shape, an elliptical shape, or a polygonal shape, and is not particularly limited, but a plate shape is preferable. Moreover, it is preferable that at least one surface that is a surface to be processed of the object to be processed is substantially a flat surface. In this case, it is because the plane polishing process by single-side polishing or double-side polishing can be performed suitably. Moreover, although the material of a to-be-processed object can mention glass, a silicon | silicone, etc., it should set suitably according to the objective of a plane polishing process, and is not specifically limited.

  The target thickness of the object to be processed, that is, the desired thickness of the object to be processed after the surface polishing process should be appropriately set according to the purpose of the surface polishing process, and is not particularly limited. Specifically, although not particularly limited, the target thickness of the object to be processed is 0.05 to 5 mm when applied to manufacture of a magnetic recording medium, and when applied to manufacture of a photomask. 0.05 to 5 mm, preferably 0.05 to 5 mm when applied to device manufacture.

  Further, the initial thickness of the object to be processed, that is, the thickness of the object to be processed before the surface polishing process should be appropriately set according to the purpose of the surface polishing process, and is not particularly limited. Specifically, although not particularly limited, the initial thickness of the workpiece is 1.01 to 1.50 times the target thickness of the workpiece, or 1 than the target thickness of the workpiece. It is preferable to be larger by ~ 1000 μm.

  As described above, the surface polishing processing method according to the present invention uses the surface protection member having a thickness of 0.8 times or more the target thickness of the object to be processed, and the surface protection member is provided at the edge of the object to be processed. Surface polishing is performed in a state of being adjacent or close to each other. According to the present invention, in a polishing process of an object to be processed such as a magnetic recording medium substrate or a photomask substrate, the surface protection of a processing carrier or a processing frame having a predetermined thickness with respect to a target thickness of the object to be processed By using the member, it is possible to prevent the sagging. The processing carrier and the processing frame will be described later.

  More specifically, for example, when the target thickness of the substrate to be processed is 0.50 mm, a processed carrier having a thickness of 0.50 mm can be used as the face protection member. Here, by placing a substrate having an initial thickness of 0.53 mm before polishing in the opening of the processing carrier and performing polishing for a predetermined time, a substrate having a target thickness of 0.50 mm can be obtained without causing any dripping. Can be completed.

  FIG. 1 shows (a) a schematic horizontal sectional view showing an aspect of a conventional flat polishing process, and (b) a schematic horizontal sectional view showing an aspect of the flat polishing process of the present invention. As will be described in detail below, for example, when the object to be processed 1 is subjected to surface polishing using the processing carriers 2 and 102, the polishing pad is placed in a state where the object to be processed is disposed in the opening of the processing carrier. The object to be processed can be planarly polished by pressing the polishing member 10 such as the above to the surface to be processed and sliding the polishing member with respect to the object to be processed.

  At this time, in the conventional surface polishing process, as shown in FIG. 1A, a processing carrier having a thickness of about 0.5 to 0.75 times the target thickness of the workpiece 1. 102 was used. This reduces the frictional resistance generated between the polishing member and the processing carrier, thereby reducing deterioration due to wear of the processing carrier and the polishing member. Furthermore, when the processing carrier has a gear portion at the outer edge portion. If so, it is to reduce the load on the gear portion. Moreover, even if the target object has a slightly different target thickness, the thickness of the processing carrier is sufficiently thin and can be diverted. In this case, as indicated by an arrow in FIG. 1A, it is considered that the polishing member 10 such as a polishing cloth having elasticity generally hits the edge of the workpiece 1 and the surface sagging occurs.

  On the other hand, in the planar polishing process of the present invention, as shown in FIG. 1B, the thickness of the target thickness of the workpiece 1 is 0.8 times or more the target thickness of the workpiece 1. The processing carrier 2 is used. According to the present invention, as shown by the arrow in FIG. 1B, the polishing member 10 is bridged by the processing carrier 2, so that the polishing member 10 is placed on the edge of the workpiece 1 as in the prior art. There is no strong hit, and it is possible to prevent or reduce dripping.

  As described above, the thickness of the surface protection member is 0.8 times or more, preferably 0.9 to 1.01 times the target thickness of the workpiece. However, the thickness of the sagging protection member is preferably set as appropriate according to the characteristics of the polishing member such as the material of the polishing surface plate used for planar polishing and the hardness of the polishing pad. Specifically, when a polishing member such as a hard pad or a polishing surface plate is used, since the sinking of the pad is small, it is preferable that the thickness of the surface protection member is equal to the target thickness. On the other hand, when a polishing member such as a soft pad is used, it is preferable to make the thickness of the surface protection member smaller than the target thickness.

More specifically, when a workpiece is subjected to surface polishing using a processed carrier, and the processed carrier is used as a face protection member, the processed carrier has a thickness that satisfies Formula I. It is preferable.
(B−A) /B≦0.2 Formula I
(In the formula, A indicates the thickness of the processed carrier, and B indicates the target thickness of the workpiece.)

  As described above, the use of a processed carrier having a thickness such that the value of (B−A) / B is 0.2 or less can prevent or reduce the sagging as described above. On the contrary, when the processing carrier having the thickness of (B−A) / B exceeding 0.2 is similarly polished and the workpiece is finished to the target thickness, the surface sagging may occur.

In addition, when the workpiece is subjected to surface polishing using the processing frame, and the processing frame is used as a surface protection member, the processing frame preferably has a thickness that satisfies Formula II.
(BC) /B≦0.2 Formula II
(In the formula, B represents the target thickness of the workpiece, and C represents the thickness of the processing frame.)

  As described above, by setting the thickness of the processing frame so that the value of (B−C) / B is 0.2 or less, the sagging can be prevented or reduced. In addition, using the processing carrier and the processing frame, the processing frame is disposed between the processing carrier and the object to be processed, that is, the processing frame is disposed in the opening of the processing carrier, and further the object to be processed However, in the case where the surface is polished in the state where it is disposed in the opening of the processing frame, the thickness of the processing carrier satisfies the above formula I and the thickness of the processing frame satisfies the above formula II, so Can be prevented. However, in the case of using the processed carrier and the processed frame, when the thickness of the processed frame satisfies the above formula II, the thickness of the processed carrier does not necessarily satisfy the above formula I.

  The thickness of the surface protection member may be larger than the target thickness of the object to be processed. Specifically, the value of (B−A) / B or (B−C) / B may be negative. This is because when the thickness of the surface protection member is set larger than the target thickness of the object to be processed, the object can be achieved by polishing the surface protection member together with the object to be processed to the target thickness. In this case, it is preferable to select a material for the sagging protection member that has better workability or an equivalent material than the workpiece. If the thickness of the surface protection member is set to be larger than the target thickness of the object to be processed, if the workability of the surface protection member becomes slower than that of the object to be processed, there is a possibility that the processing surface may be curved. Because. Thus, the thickness of the surface protection member is set to be larger than the target thickness of the object to be processed, and the surface of the object to be processed is polished to the target thickness together with the surface contact protection member. A polished workpiece can be completed. Although the thickness of the processing carrier can be set larger than the target thickness of the workpiece, considering the cost in the processing process, if the thickness of the surface protection member is set larger than the target thickness of the workpiece, It is preferable to use the frame as a drooping protection member.

  According to another aspect of the present invention, when the surface protection member is disposed adjacent to or close to the edge of the object to be processed, the surface of the surface protection member becomes the target thickness of the object to be processed. The object of the present invention can be achieved in the same manner as described above by disposing the surface protection member so as to have substantially the same height as (the surface to be processed after polishing). In other words, when the object to be processed is polished to the target thickness, the height of the step between the object surface of the object to be processed and the surface of the surface protection member on the polishing member side is not more than a predetermined length. In addition, the object of the present invention can be achieved in the same manner as described above by setting the thickness of the sagging protection member. In particular, the surface of the sagging protection member is parallel to the surface that is the target thickness of the object to be processed, and the height difference from the surface is preferably 10 μm or less, more preferably 1 to 5 μm or less. It is preferable to arrange | position. In particular, when the target thickness of the object to be processed is 1 to 1000 μm, the thickness of such a sagging protection member is effective. Here, the difference in height between the surface of the surface protection member and the surface to be processed or the height of the step is the distance between the surface of the surface protection member and the surface to be processed in the direction perpendicular to the surface to be processed. It shall be said.

  Here, the state in which the surface protection member is disposed adjacent to or close to the edge of the object to be processed is a surface so that the polishing member can be bridged over at least a part of the edge of the object to be processed, preferably the whole. The state in which the protection member is disposed, and the state in which the polishing member is disposed adjacent to or close to the edge of the object to be processed is lessened when the surface is polished. . In addition, it is preferable to appropriately set the mode of arrangement of the sagging protection member according to the desired degree of sagging prevention, the characteristics of the workpiece and the polishing member, workability, and the like. Note that the edge of the object to be processed includes the outer edge of the object to be processed and the inner edge of the object to be processed when the object to be processed has an opening. More specifically, the sagging protection member can be disposed outside the workpiece. In this case, the processing carrier or the processing frame can be used as the surface protection member. Further, when the object to be processed has an opening, such as a hard disk substrate, that is, when the shape of the object to be processed is annular or the like, the surface protection member is further provided with the opening of the object to be processed. It can also be arranged inside the part. In this case, the processing frame can be a surface protection member.

  In the case where the surface protection member is disposed outside the workpiece, the surface protection member preferably has an opening. In the step of surface polishing, the opening of the surface protection member is the object to be processed. It is preferable that the object to be processed is subjected to surface polishing in a state where the object to be processed is disposed adjacent to or in the vicinity of the outer edge portion, that is, in a state where the object to be processed is disposed in the opening of the surface protection member. Thereby, the surface drooping protection member can be more preferably disposed adjacent to or close to the outer edge portion of the object to be processed, and the surface dripping of the outer edge of the object to be processed can be suitably prevented or reduced.

  In this case, the opening of the surface protection member is an opening for fitting the object to be processed in the surface polishing step, and has a shape and size that can be disposed adjacent to or close to the outer edge of the object to be processed. Preferably, the shape and size of the opening can be appropriately determined according to the shape and size of the workpiece. More specifically, it is preferable that the shape of the opening portion of the surface protection member is substantially similar to the shape of the outer edge of the object to be processed. That is, it is preferable that the shape of the opening of the surface protection member is a circular shape, a pseudo-circular shape, an elliptical shape, or a polygonal shape depending on the shape of the workpiece to be subjected to the surface polishing process.

  Moreover, it is preferable that the dimension of the opening part of a drooping protection member is larger than 1 time of the dimension of the outer edge of a to-be-processed object, and is 1.05 times or less. For example, when the shape of the opening of the surface protection member is circular and the shape of the outer edge of the object to be processed is circular, the diameter of the opening of the surface protection member is equal to that of the object to be processed. It is preferable that it is larger than 1 times the diameter of the outer edge and not larger than 1.05 times. In particular, when performing double-sided polishing, it is preferable that the size of the opening of the surface protection member is greater than 1.0001 times and less than 1.02 times the size of the outer edge of the workpiece. In the case of performing single-side polishing, it is preferable that the size of the opening of the surface protection member is greater than 1.0001 times and less than 1.04 times the size of the outer edge of the workpiece.

  If the gap between the opening of the surface protection member and the object to be processed is too large, the surface may be increased due to the polishing member sinking into the space. In addition, if the gap is too large, the object to be processed may move more than necessary in the opening of the surface protection member during polishing of the object to be processed, and the surface may be generated. Further, in the case of performing a planar polishing process using a polishing liquid, the polishing liquid may stay in the gap, and the outer edge portion of the object to be processed may be scraped off more than necessary, thereby causing a surface sag. . In order to prevent these problems, it is preferable to make the gap as small as possible to prevent the sagging. On the other hand, if the gap is too small, it may be difficult to put a workpiece into and out of the opening of the surface protection member and workability may be reduced. In addition, when performing planar polishing using polishing abrasive grains, depending on the polishing abrasive grains used, the polishing abrasive grains may bite into the gaps, and uniform polishing may not be possible. Furthermore, in general, when performing double-side polishing, when the workpiece is placed on the processing carrier and polished, the workpiece is rotated in the opening during the processing, so that uniform polishing is performed. For this reason, a certain clearance is required between the object to be processed and the opening of the surface protection member. On the other hand, in general, in the case of performing single-side polishing, the workpiece is not rotated because the workpiece is processed while being fixed. For this reason, it is preferable to make the gap as small as possible.

  More specifically, in the case where the workpiece is subjected to surface polishing using a processing carrier having an opening, and the processing carrier is disposed outside the workpiece and used as a surface protection member. Preferably, the shape of the opening of the processing carrier is substantially similar to the shape of the outer edge of the workpiece. That is, it is preferable that the shape of the opening of the processing carrier is a circle, an ellipse, or a polygon according to the shape of the object to be processed.

In particular, when the shape of the opening of the processing carrier is circular and the shape of the outer edge of the workpiece is circular, the diameter of the opening of the processing carrier preferably satisfies Formula III.
(D−E) /E≦0.05 Formula III
(In the formula, D represents the diameter of the opening of the processed carrier, and E represents the outer diameter of the workpiece.)

  In addition, when a workpiece is subjected to surface polishing using a processing frame having an opening, and the processing frame is disposed outside the workpiece and used as a surface protection member, the processing frame Preferably, the shape of the opening is substantially similar to the shape of the outer edge of the workpiece. That is, it is preferable that the shape of the opening of the processing frame is a circle, an ellipse, or a polygon depending on the shape of the workpiece.

In particular, when the shape of the opening of the processing frame is circular and the shape of the outer edge of the workpiece is circular, the diameter of the opening of the processing frame preferably satisfies the formula IV.
Circular (FE) /E≦0.05 with diameter satisfying formula IV Formula IV
(In the formula, E represents the outer diameter of the workpiece, and F represents the inner diameter of the processing frame.)

  In addition, as described above, when the workpiece has an opening and the surface protection member is disposed inside the opening of the processing object, in the step of surface polishing, the surface protection member Is preferably disposed in the state adjacent to or close to the inner edge of the object to be processed, that is, in a state where the surface protection member is disposed in the opening of the object to be processed, it is preferable that the object to be processed is subjected to surface polishing. . Thereby, the drooping protection member can be more preferably disposed adjacent to or close to the inner edge of the object to be processed, and the drooping of the inner edge of the object to be processed can be suitably prevented or reduced.

  In this case, it is preferable that the sagging protection member has a shape and a dimension that can be disposed adjacent to or close to the opening of the workpiece, i.e., the inner edge, and the shape and dimension of the member are the same as those of the opening of the workpiece. It can be determined appropriately according to the shape and dimensions. More specifically, it is preferable that the shape of the surface protection member is substantially similar to the shape of the inner edge of the object to be processed. That is, it is preferable that the shape of the sagging protection member is a circular shape, a pseudo-circular shape, an elliptical shape, or a polygonal shape according to the shape of the opening of the workpiece to be subjected to the surface polishing process.

  In addition, when the workpiece has an opening and the surface protection member is disposed inside the opening of the processing object, the surface protection member is disposed outside the processing object. For the same reason, it is preferable that the dimension of the surface protection member is 0.95 times or more and less than 1 time the size of the opening of the object to be processed. For example, when the shape of the surface protection member is circular and the shape of the opening of the object to be processed is circular, the diameter of the opening of the surface protection member is equal to the outer edge of the object to be processed. The diameter is preferably 0.95 times or more and less than 1 time. In particular, when performing double-side polishing, it is preferable that the dimension of the surface protection member is 0.95 times or more and less than 1.0 times the dimension of the opening of the object to be processed. In the case of performing single-side polishing, it is preferable that the size of the surface protection member is 0.99 times or more and less than 1.0 times the size of the opening of the object to be processed.

  Further, according to another aspect, the distance between the workpiece and the surface protection member is preferably 0.5 mm or less, more preferably 0.1 to 0.3 mm. By setting the shape and dimensions, the object of the present invention can be achieved more suitably in the same manner as described above. In particular, when the dimension of the object to be processed is 10 to 30 mm, the shape and the dimension of such a sagging protection member are effective. Here, the dimension of the object to be processed is the longest length in any direction of the surface to be processed (for example, the diameter of the object to be processed when the object to be processed is circular). ).

  In FIG. 2, the typical top view which shows the aspect of the plane grinding | polishing process of this invention is shown. FIG. 2A shows a mode in which the annular workpiece 1 is subjected to surface polishing using the processing carrier 2 and the processing frames 3 and 4. In the embodiment of FIG. 2A, a circular processing carrier 2 having four circular openings, a circular outer edge processing frame 3 having a circular opening, and a circular inner edge. A processing frame 4 is used. The thicknesses of the processing carrier, the outer edge processing frame, and the inner edge processing frame are within a predetermined range with respect to the thickness of the object to be processed as described above (not shown). An outer edge processing frame is disposed in the opening of the processing carrier, an object to be processed is disposed in the opening of the outer edge processing frame, and an inner edge processing frame is further disposed in the opening of the object to be processed. Do. Moreover, in the aspect of FIG.2 (b), the aspect which planarly polishes the square-shaped to-be-processed object 1 using the process carrier 2 and the process frame 3 is shown. In the embodiment of FIG. 2B, a circular processing carrier 2 having four rectangular openings and a rectangular outer edge processing frame 3 having quadrangular openings are used. Moreover, in the aspect of FIG.2 (c), the aspect which carries out the surface grinding | polishing process of the square-shaped to-be-processed object 1 using the process carrier 2 and the process frame 3 is shown. In the embodiment of FIG. 2 (c), a circular processing carrier 2 having four circular openings and a circular outer edge processing frame 3 having quadrangular openings are used. 2 (b) and 2 (c), the thickness of each of the processing carrier and the outer edge processing frame is within a predetermined range with respect to the thickness of the workpiece as described above (not shown). . An outer edge processing frame is disposed in the opening of the processing carrier, and an object to be processed is disposed in the opening of the outer edge processing frame, and planar polishing is performed. By disposing the processing carrier and the processing frame having a predetermined thickness in this way, the object to be processed can be subjected to surface polishing processing without causing the sagging.

  As described above, the anti-sagging member can be applied not only to the outer periphery of the object to be processed, but also to a member having an opening on the inner side, such as a hard disk substrate. According to the present invention, the inner edge of the object to be processed Anyone can be prevented. Thus, it can be seen that the present invention can cope with various shapes, and its application is not widely limited except for polishing a magnetic recording medium substrate, a photomask substrate, or the like.

  The material of the surface protection member is not particularly limited, and examples thereof include glass epoxy, epoxy, polyurethane, carbon, iron, copper, brass, aluminum, SUS, carbon, aramid, PVC, PP, PE, and PS. .

  In particular, when the processed carrier is used as a surface protection member, it is not particularly limited. However, since the material of the processed carrier is easily available as a material, glass epoxy, epoxy, polyurethane, carbon, iron , Copper, brass, aluminum, SUS, carbon, aramid, PVC, PP, PE, PS and the like. Although the material of the processing carrier varies depending on the material and application of the workpiece to be processed, glass epoxy, epoxy, brass, SUS or the like is generally used. In addition, since the thickness of the processed carrier is substantially the target thickness of the workpiece, the material of the processed carrier preferably has wear resistance and chemical resistance against the polishing conditions and the polishing liquid used.

  Further, in the case where the processing frame is used as a surface protection member, it is not particularly limited as in the case of the processing carrier. However, since it is easy to obtain as a material of the processing frame, glass epoxy, epoxy, polyurethane , Carbon, iron, copper, brass, aluminum, SUS, carbon, aramid, PVC, PP, PE, PS and the like. The material of the processing frame preferably has chemical resistance against the polishing conditions and the polishing liquid used. The processing frame can be made of a material similar to the object to be processed. The processing carrier is preferably used repeatedly, but the processing frame can be disposable and may be polished in the same manner as the object to be processed. In this case, as described above, the value of (B−C) / B of the processing frame may be negative. On the other hand, if a wear-resistant material is used for the processing frame, the value of (BC) / B is preferably 0 to 0.2.

  The flat polishing process includes a single-side polishing process and a double-side polishing process, and can be performed using a single-side polishing machine or a double-side polishing machine. That is, the surface polishing process according to the present invention is not limited to the case where a double-side polishing machine is used, and even if it is a single-side polishing machine that does not normally require the use of a carrier, the same effect can be obtained by using a processing frame as a surface protection member. Is obtained. Hereinafter, single-side polishing processing and double-side polishing processing will be described.

  In FIG. 3, the schematic diagram which shows the aspect which performs the plane polishing process of this invention with a single-side polisher is shown. Although not particularly limited, as shown in FIG. 3, in the case of single-side polishing, as a polishing member, a circular surface plate with a groove cut or a polishing pad 12 on the surface plate 11. The attached rotary circular surface plate 10 can be used. Further, the workpiece 1 is attached to the rotatable fixing jig 13. At this time, the processing frame 3 having the predetermined thickness may be attached to the fixing jig at the same time, or the processing frame may be inserted into the workpiece attached to the fixing jig. At this time, the processing frame having a predetermined thickness and the workpiece are placed on the same plane of the fixing jig. Furthermore, the workpiece to be processed attached to the fixing jig is brought into horizontal contact with the rotary surface plate, the rotary surface plate is pressed against the surface to be processed, and the rotary surface plate and the fixing jig are attached. By rotating each, the surface of the object to be processed can be polished by sliding the rotary surface plate against the object to be processed. At this time, polishing may be performed while adding abrasive grains.

  In FIG. 4, the schematic diagram which shows the aspect which performs the plane polishing process of this invention with a double-side polisher is shown. Although not particularly limited, as shown in FIG. 4, in the case of double-side polishing, a pair of upper and lower polishing members 10 are used, and each polishing member is formed by grooving a circular surface plate, A rotary circular surface plate in which the polishing pad 12 is attached on the surface plate 11 can be used. Further, the object to be processed is disposed on the processing carrier having the predetermined thickness, and the object to be processed and the processing carrier are disposed between the upper and lower surface plates. Furthermore, the workpiece placed in the processing carrier is sandwiched between the upper and lower rotary surface plates, the rotary surface plate is pressed against the upper and lower surfaces of the workpiece, and the rotary surface plate is rotated. By sliding the rotary surface plate against the object to be processed, both surfaces of the object to be processed can be simultaneously polished. At this time, polishing may be performed while adding abrasive grains.

  Here, as shown in FIG. 4, the processing carrier is a jig for fixing the object to be processed in double-side polishing of the object to be processed, and the tool itself can be rotated. As an advantage of using the processed carrier as a beveling protection member, it is possible to dramatically improve the beveling of the object to be processed as compared with the conventional carrier by controlling the thickness of the carrier. In particular, it is effective for mass production of the same object to be processed because the surface run can be improved without increasing the number of manufacturing steps. In addition, the processing carrier should just be a shape which can arrange | position a to-be-processed object inside, and the thing of the magnitude | size which can fix one or several to-be-processed object can be used.

  Further, as shown in FIG. 3, the processing frame can be disposed on the outer periphery of the workpiece even when it is not necessary to use a processing carrier as in single-side polishing. Further, as shown in FIG. 2, the processing frame can be disposed between the processing carrier and the object to be processed even when performing double-side polishing. As an advantage of using the processing frame as a surface protection member, it is possible to cope with a workpiece having a different target thickness by controlling the thickness of the processing frame. For this reason, it is particularly effective to use the processing frame as a bevel protection member for high-mix low-volume production.

  Further, although not particularly limited, as the polishing member, a circular surface plate obtained by grooving or a rotary circular surface plate in which a polishing cloth is attached on the surface plate can be used. As hard polishing cloth, hard polyurethane MHN15A (Rodale), LP-57 and LP-87 (Takasago Trading), GM2009ZS (Cobblestone Sangyo), hard non-woven Suba800 (Rodale), N0573 ( Kanebo). Moreover, as a soft polishing cloth, Suba400 (manufactured by Rodel), K0017 (manufactured by Kanebo) as a non-woven fabric system, N0048, N0054, N0058 (manufactured by Kanebo), Supreme RN-H (manufactured by Kanebo), Seagull 7355 ( Toray Cortex).

  Embodiments of the present invention will be described below with reference to the accompanying drawings. However, the embodiments described below do not limit the present invention.

[Experimental Examples 1-7]
A substrate having an outer diameter of 65 mm, an inner diameter of 20 mm, and a thickness of 0.65 mm using single crystal silicon was prepared as an object to be processed. Further, as the processing carrier, the material is glass epoxy, the diameter of the opening is 65.5 mm, and as shown in Tables 1 and 2, the thickness of the processing carrier is A, and the target thickness of the workpiece is B. The thing which has the thickness from which the value of (B-A) / B becomes 0-0.3 was prepared. The polishing cloth is Suba400 (Rodel), which is a non-woven fabric, and a polishing liquid (Colloidal Silica / Nissan Chemical: 5% -SSS) is used. Polishing was performed for a predetermined time until it reached 60 mm. After polishing, the substrate was washed and dried, and the surface of the outer edge of the object to be processed was observed using OSA.

[Experimental Examples 8 to 16]
A substrate similar to that used in Experimental Example 1 was prepared. Further, as the processing carrier, the material is SUS304, and as shown in Tables 1 and 2, when the diameter of the opening of the processing carrier is D and the outer diameter of the workpiece is E, (DE) / E Having a diameter of the opening with a value of 0 to 0.1 and a thickness of 0.60 mm equal to the target thickness was prepared. Using these objects to be processed and the processed carrier, polishing was performed under the same conditions as in Experimental Example 1, and the surface of the outer edge of the object to be processed was observed using OSA.

[Experimental Examples 17 to 25]
A substrate similar to that used in Experimental Example 1 was prepared. Further, a processed carrier having a material of epoxy, a diameter of the opening of 75 mm, and a thickness of 0.50 mm was prepared. Further, the material of the processing frame is SUS304, and as shown in Table 1, the value of (FE) / E when the diameter of the opening of the processing frame is F and the outer diameter of the workpiece is E. Has a diameter of the opening part of 0 to 0.1 and a thickness of 0.57 mm. Polishing was performed under the same conditions as in Experimental Example 1 using these objects to be processed, processing carriers, and processing frames, and the surface of the outer edge of the objects to be processed was observed using OSA.

[Experimental examples 26 to 34]
A substrate similar to that used in Experimental Example 1 was prepared. Further, a processed carrier having a material of brass, an opening having a diameter of 75 mm, and a thickness of 0.50 mm was prepared. Further, as the processing frame, the material is carbon, the diameter of the opening is 66.3 mm, and as shown in Table 1, when the thickness of the processing frame is C and the target thickness of the workpiece is B ( A material having a diameter of an opening having a value of B−C) / B of −0.2 to 0.3 was prepared. Using these workpieces, processing carrier, and processing frame, polishing is performed under the same conditions as in Experimental Example 1 except that an alumina-based polishing liquid is used, and the surface edge of the outer edge of the workpiece is removed by OSA. And observed.

[Surface observation]
OSA (Optical Surface Analyzer, manufactured by Candela) was used to observe the drooping of the outer edge of the object to be processed after polishing. Each object to be processed after polishing was scanned from the outermost edge to the inside for 17 mm, and the width of the surface was confirmed. FIG. 5 shows the results of surface drooping observation by OSA of the polished object obtained by the experimental example. 5A shows the result of Experimental Example 7, and FIG. 5B shows the result of Experimental Example 3. In the graph, the vertical axis represents height and the horizontal axis represents width.

  Moreover, about the to-be-processed object obtained by each experimental example, the surface droop width | variety was calculated | required as follows. A straight line was drawn from the inner side toward the outer peripheral part, and a point deviated from the straight line was measured to determine how many mm from the outer peripheral end part, and was used as the value of the surface drop. (Refer to Fig. 5 (a)) Table 1 shows the material, thickness and opening diameter of the processing carrier and processing frame used in each experimental example. Table 2 shows the relationship between the thickness and dimensions of the object to be processed and the processing carrier and / or the processing frame in each experimental example, and the surface wetting width of the object to be processed after polishing. In Table 2, the difference between the object to be processed and the processing carrier (or processing frame) is the difference between the object to be processed and the processing carrier when the processing frame is not used (Examples 1 to 16). When the processing frame is used (Examples 17 to 34), the difference between the workpiece and the processing frame is shown. In Table 2, the difference in thickness between the object to be processed and the processing carrier (or processing frame) indicates the difference in thickness after polishing. That is, when a processing frame having a thickness larger than the target thickness is used (Examples 26 to 28), the difference in thickness between the workpiece after polishing and the processing frame is 0 mm.

[Examination of processing carrier thickness]
As shown in Experimental Examples 1 to 7 in Table 1, when the thickness of the processing carrier is A and the target thickness of the workpiece is B, the value of (B−A) / B exceeds 0.2. As a result, a surface runout of about 7 mm occurred at the outer edge of the object to be processed after polishing. On the other hand, in the case where the value of (B−A) / B is 0.2 or less, the drooping of the outer edge of the workpiece after polishing was improved (see the arrow in FIG. 5B). . Similarly, as shown in Experimental Examples 26 to 34 in Table 1, when the thickness of the processing frame is greater than (BC) / B, a large surface sagging has occurred. However, in the case of 0.2 or less, the dripping improved.

[Examination of processing carrier opening diameter]
As shown in Experimental Examples 8 to 16 in Table 1, as the gap between the opening of the processing carrier and the outer diameter of the object to be processed becomes smaller, the sagging is further improved. Similarly, as shown in Experimental Examples 17 to 25 in Table 1, the sagging improved by setting the dimensions of the processing frame within a predetermined range. However, in the case of a carrier in which the opening diameter of the processed carrier or the processing frame is exactly the same as the outer diameter of the processing object, a processing object that does not fit in the opening of the processing carrier or the processing frame may appear due to a manufacturing error. However, it is preferable to increase the opening diameter of the processing carrier or processing frame.

  Thus, if the gap between the object to be processed and the opening of the processing carrier or the processing frame is too small, it becomes difficult to put in and out the object to be processed, or depending on the abrasive grains, the gap may be caught in the gap, and uniform polishing may occur. It may not be possible. However, if the gap is too large, as shown in Experimental Examples 14 to 16 and 23 to 25 in Table 1, the object to be processed moves more than necessary in the openings of the processing carrier and the processing frame, and the polishing pad sinks. Because of this, it is considered that the surface is increased.

  Furthermore, Zygo (manufactured by Zygo, model number: GPI-XP, the principle of which is the surface shape error (flatness, sphericity) using interference of the laser reflected light from the measured object and the reference surface (generator) This was an apparatus for measuring with high accuracy.) The appearance of the outer edge of the processed object after polishing was observed. 6 and 7 show the results of appearance observation by Zygo of the polished object obtained in the experimental example. 6 shows the result of Experimental Example 7, and FIG. 7 shows the result of Experimental Example 3. From these Zygo results, it can be seen that the present invention can prevent sagging.

  As is apparent from the above, according to the present invention, the thickness of the processing carrier or processing frame is set to a predetermined range, and the opening of the processing carrier or processing frame is set to a predetermined range. As a result, it was possible to suitably prevent the sagging of the workpiece. For this reason, according to the present invention, it is possible to prevent the effective recording area of the magnetic recording substrate from being reduced due to the surface deflection, and in particular, the effective recording area of the small-diameter substrate can be greatly improved.

(A) The typical horizontal direction sectional view which shows the aspect of the conventional surface polishing process, and (b) The typical horizontal direction sectional view which shows the aspect of the surface polishing process of this invention is shown. The typical top view which shows the aspect of the plane polishing process of this invention is shown. The schematic diagram which shows the aspect which performs the plane polishing process of this invention with a single-side polisher is shown. The schematic diagram which shows the aspect which performs the plane polishing process of this invention with a double-side polisher is shown. The result of the surface drooping observation by OSA of the to-be-processed object obtained by the experiment example is shown. The result of the external appearance observation by Zygo of the to-be-processed object obtained by the experiment example is shown. The result of the external appearance observation by Zygo of the to-be-processed object obtained by the experiment example is shown.

Explanation of symbols

1: Processing object 2, 102: Processing carrier 3: Outer edge processing frame 4: Inner edge processing frame 10: Polishing member 11: Surface plate 12: Polishing pad 13: Fixing jig

Claims (11)

A method for subjecting a workpiece to surface polishing,
Providing a fringing protection member having a thickness of 0.8 times or more the target thickness of the workpiece;
A surface polishing method for the object to be processed, the method comprising the step of surface polishing the object to be processed in a state where the surface protection member is disposed adjacent to or close to an edge of the object to be processed.   In the step of polishing the surface, the surface drooping protection member has an opening, and in the step of planar polishing, the opening of the surface drooping protection member is disposed adjacent to or close to an outer edge of the workpiece. The surface polishing method according to claim 1, wherein the processed material is surface polished.   The shape of the outer edge of the workpiece is substantially similar to the shape of the opening of the surface protection member, and the size of the opening of the surface protection member is the size of the outer edge of the processing object. The surface polishing method according to claim 2, which is greater than 1 time and 1.05 times or less.   The surface polishing processing method according to claim 1, wherein the surface drooping protection member is a processing carrier.   The surface polishing processing method according to claim 1, wherein the surface drooping protection member is a processing frame.   The planar polishing method according to any one of claims 2 to 5, wherein the shape of the opening of the surface drooping protection member is a circle, a pseudo circle, an ellipse, or a polygon. A method for subjecting a workpiece to surface polishing,
A step of arranging the surface protection member adjacent to or adjacent to the edge of the object to be processed, wherein the surface of the surface protection member has substantially the same height as the surface to be the target thickness of the object to be processed; Arranging the drooping protection member so that,
A surface polishing method for the object to be processed, the method comprising the step of surface polishing the object to be processed in a state where the surface protection member is disposed adjacent to or close to an edge of the object to be processed.   The surface polishing method according to claim 1, wherein in the polishing step, both surfaces of the object to be processed are polished.   In the arranging step, the surface of the surface protection member is arranged so as to be parallel to a surface to be a target thickness of the object to be processed, and a height difference from the surface is 200 μm or less. A method for polishing a surface of an object to be processed according to claim 7 or 8.   A surface-polished workpiece obtained by the method according to claim 1. A surface drooping protection member for protecting the surface droop of the object to be processed by arranging it adjacent to or close to the edge of the object to be processed when the object to be processed is surface-polished. A surface drooping protection member having a thickness of 0.8 times or more the target thickness of the workpiece.

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