JP2575934B2 - Hard brittle material wrapping method and apparatus - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method and an apparatus for wrapping hard and brittle materials.

2. Description of the Related Art As a lapping method of applying a high-precision planar polishing finish to a member to be polished made of a hard and brittle hard and brittle material such as an optical glass, a semiconductor substrate, and a ceramic material, a soft material such as urethane rubber, suede, and felt is wrapped. Using a soft wrap provided on the surface, while pressing the member to be polished on the wrap to be rotated, a slurry type polishing liquid containing free abrasive grains such as cerium oxide or aluminum oxide is supplied between the two. An abrasive lapping method is known. In this loose abrasive lapping method, a part of the polished member is pushed into the lap surface by the elastic deformation of the lap surface accompanying the pressing of the polished member, so that the corner portion is polished more remarkably than the other portions. As a result, edge dripping and the like occurred, and the processing accuracy in planar polishing was not sufficiently obtained.

Problems to be Solved by the Invention In contrast, there has been proposed a fixed abrasive lapping method in which a fixed abrasive wrap in which abrasive grains are fixed using a binder is used in place of the soft wrap. In the fixed abrasive lapping method, there is an advantage that the processing accuracy in the planar polishing can be sufficiently obtained without causing edge curl or the like because there is no surface deformation of the fixed abrasive wrap. However, since the polishing is performed with high precision for the purpose of obtaining an extremely smooth flat surface, clogging and crushing are liable to occur, and there is a disadvantage that the polishing efficiency is reduced after a certain period of time.

As a compromise between the free abrasive lapping method and the fixed abrasive lapping method, a combined use method of supplying a slurry-like polishing liquid containing free abrasive grains onto the fixed abrasive wrap can be considered. This combination method promotes the autogenous action of the polished surface in the fixed abrasive wrap, that is, the regenerating action of regenerating a new cutting edge with wear of the abrasive grains, by adding loose abrasive grains to cause clogging and crushing. And so on. However, since the polishing liquid is not sufficiently supplied between the member to be polished and the fixed abrasive wrap, the polishing efficiency cannot always be sufficiently improved.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a method and an apparatus for wrapping a hard and brittle material which can maintain good processing accuracy and sufficiently obtain a polishing efficiency. It is in.

Means for Solving the Problems In order to achieve the above object, the gist of the present invention is to provide a hard brittle material lapping method for subjecting a member to be polished made of a hard brittle material to a planar polishing finish. A lap provided with a first grindstone portion having abrasive grains fixed with a binder on a polishing surface; and a second grindstone portion having the abrasive grains fixed with a binder and having a lower hardness than the first grindstone portion. By pressing the member to be polished against the polishing plane while rotating the correction ring relative to the annular correction ring provided on the correction surface abutting against the center of the wrap and rotating the correction ring, the member to be polished is To be subjected to a plane polishing finish.

Function and Effect of the First Invention In this way, the first abrasive grains fixed with a binder
A lap provided with a grindstone portion on a polishing surface, an annular correction ring provided on a correction surface for fixing abrasive grains with a binder and having a second grindstone portion having a lower hardness than the first grindstone portion on the polishing surface; However, the member to be polished is pressed against the polishing plane while being relatively rotated about the center axis of the wrap and the correction ring is rotated, whereby the member to be polished is subjected to plane polishing. Therefore, (a)
By the sliding contact between the first grindstone portion of the lap and the second grindstone portion of the correction ring, the grindstone fixed to the second grindstone portion of the correction ring and the abrasive grain fixed to the first grindstone portion of the lap collide with each other. Since the crushing of the abrasive grains is performed continuously and the cutting edge of the abrasive grains on the polishing plane of the lap is constantly regenerated, the clogging and crushing of the first grindstone portion of the lap is eliminated, High polishing efficiency can be obtained. (B) Further, even under the condition that the fixed abrasive grains of the first grindstone portion of the lap and the second grindstone portion of the correction ring collide with each other and are crushed as described above,
Since the hardness of the second grindstone portion of the correction ring is lower than the hardness of the first grindstone portion of the lap, the shape accuracy of the polished plane of the first grindstone portion of the lap is not impaired, and the extremely brittle material of the brittle material is extremely smooth. A plane can be obtained with high accuracy. (C) Further, since the abrasive grains mainly dropped off from the second grindstone portion having relatively low hardness by crushing or the like are appropriately supplied as free abrasive grains to the polishing plane and participate in the polishing, the polishing efficiency is further enhanced. (D) Further, the abrasive grains released from the second grinding stone portion by crushing or the like have a relatively small diameter, and are captured by the unevenness of the polishing plane of the first grinding stone portion, and the rolling thereof is suitably suppressed. In this case, scratches due to rolling of the free abrasive grains are prevented, and an extremely smooth polished surface is obtained, as compared with the free abrasive grain method using a metal wrap.

A second aspect of the present invention is a device for practicing the method of the present invention suitably. The gist of the present invention is a hard brittle material lapping apparatus for subjecting a member to be polished made of a hard brittle material to a planar polishing finish. (A) a lap which is provided with a first grindstone portion having abrasive grains fixed with a binder on a polishing plane and is driven to rotate around a central axis; and (b) the abrasive grains are fixed with a binder and the first A second grindstone portion having a hardness lower than that of the first grindstone portion is provided on a correction surface in contact with the polishing plane, and in a state in which the correction surface is in contact with the polishing surface, an annular ring that rotates around a center axis of position fixation; And (c) a pressing member fitted into the correcting ring and pressing the member to be polished toward the polishing surface of the lap.

In this manner, when the lap provided with the first grindstone portion on which the abrasive grains are fixed by the binder on the polishing plane is driven to rotate around the central axis, the abutment with the polishing plane is achieved. An annular correction ring, which is a second grindstone portion in which the corrected surface is a second grindstone portion in which abrasive grains are fixed by a binder and has a lower hardness than the first grindstone portion,
The member to be polished, which is rotated around the center axis of the fixed position and pressed toward the polishing plane of the lap by a pressing member fitted in the correction ring, is polished. For this reason, (a) the first grindstone portion of the lap and the second
The grinding wheel fixed to the second whetstone portion of the correction ring and the abrasive grain fixed to the first whetstone portion of the lap collide with each other by sliding contact with the whetstone portion, so that the abrasive grains are continuously crushed. Since the cutting edge of the abrasive grains on the polishing plane of the lap is always regenerated, clogging and crushing of the first grindstone portion of the lap are eliminated, so that a high polishing efficiency can be obtained. (B) Also, as described above, even in a situation where the fixed abrasive grains of the first grindstone portion of the lap and the second grindstone portion of the correction ring collide with each other and are crushed, the second grindstone of the correction ring is used. Since the hardness of the portion is lower than the hardness of the first grindstone portion of the lap, the shape accuracy of the polishing plane of the first grindstone portion of the lap is not impaired,
An extremely smooth plane of hard and brittle material is obtained with high precision.
(C) Further, since the abrasive grains mainly dropped off from the second grindstone part having relatively low hardness by crushing or the like are appropriately supplied as free abrasive grains to the polishing plane and participate in the polishing, the polishing efficiency is further enhanced. (D) Further, the abrasive grains released from the second grinding stone portion by crushing or the like have a relatively small diameter, and are captured by the unevenness of the polishing plane of the first grinding stone portion, and the rolling thereof is suitably suppressed. In this case, scratches caused by the rolling of the free abrasive grains are prevented, and a very smooth polished surface is obtained, as compared with the free abrasive grain method using a metal wrap.

Embodiment Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a front sectional view showing a wrapping device 10 of the present invention. The rotating shaft 12 is rotatably supported around a vertical axis by a frame 28 having a disc-shaped top plate 29 via bearings 24 and 26. A small-diameter V pulley 18 is fixed to the drive shaft 16 of the drive motor 14 fixed to the frame 28, and a large-diameter V pulley 20 is fixed to the rotary shaft 12. Diameter V pulley
A wrap 36 fixed to the rotating shaft 12 is driven to rotate by the motor 14 via a belt 22 wound around 20. The wrap 36 includes a metal rotary plate 34 fixed to the rotary shaft 12 and a flat disk-shaped flat grinding wheel 30 bonded to the rotary plate 34 with an adhesive or the like. The surface polishing grindstone 30 is, for example, 1000 g of cerium oxide particles (abrasive particles) of relatively fine particles (average particle size 0.5 μm),
Polyester resin dissolved in solvent (solid content 20%
Prepared by weight: Binder) Add 200g, mix if necessary by adding viscosity modifier etc. for more than 10 hours,
It is formed by filling in a predetermined mold, sufficiently evaporating the solvent, and press-molding at a pressure of 200 kg / cm ^{2 in} a state of being sandwiched between hot plates at 130 ° C. The polishing surface 32 of the formed flat polishing wheel 30 has, for example, a pitch
Grid-shaped grooves 33 each having a width of 10 _mm and a width of 1 _mm , which are orthogonal to each other, are formed.

As shown in FIG. 2, on the annular polishing plane 32 of the plane polishing wheel 30, correction rings 42 and 48 are provided on a circle passing through a center point in the width (radial) dimension of the plane polishing wheel 30. By being arranged so that each center is located, and being supported by a guide roller (not shown) fixed to the frame 28 via a column, the rotation of the wrap 36 and the rotation around each axis ( (Rotation) is provided. As shown in detail in FIG. 3, the correction ring 42 includes a metal ring main body 38 and a plurality of disc-shaped pellets 40a having a correction surface 39 abutting on the polishing plane 32 at a lower end surface of the ring main body 38. A plurality of grindstones 40 are adhered by an adhesive or the like in a state of being arranged in a plurality in the circumferential direction. Further, as shown in detail in FIG. A whetstone part provided with, for example, eight radial grooves 43 in the circumferential direction on a correction surface 45 adhered to the ring main body 44 and abutting against the polishing plane 32
46. In addition, the grinding stones 40 and 46
Are manufactured by the same material and manufacturing process as the above-mentioned flat grinding wheel 30, but by mixing abrasive grains and a binder, adjusting compression pressure during press molding and the like, etc.
It is formed to have a hardness lower than that of 30, that is, a grinding stone structure or a degree of bonding of abrasive grains.

Plummets 50 and 51 have diameters slightly smaller than the inner diameters of correction rings 42 and 48, respectively, and
It is designed to fit inside. Plummet 50 and 51
The mounting plates 54 and 55 are interposed between the flat grinding wheel 30 and the flat surface, respectively.
Is the work material 56 and
For example, four 57s are respectively held by bonding with wax or the like. Reference numeral 58 denotes a polishing liquid supply pipe for supplying a polishing liquid onto the polishing plane 32, and 60 denotes a lap
A tank for receiving the polishing liquid diverging on 36. The correction ring 48, the mounting plate 55, the work material 57, and the weight plate 51 are not shown in FIG.

During the planar polishing of the work surfaces of the work materials 56 and 57, the weight disks 50 and 51 are fitted into the annular spaces of the correction rings 42 and 48, respectively, and press the mounting plates 54 and 55 with a predetermined pressure. With the polishing liquid supply pipe
At the same time that the water is sufficiently supplied from 58 to the polishing plane 32 of the wrap 36, the lap 36 is driven to rotate by the drive motor 14 in the direction of the arrow shown in FIG. As a result, the wrap 36 and the correction rings 42 and 48 perform a relative rotational movement about the rotation axis 12 while the correction rings 42 and 48
Based on the difference in peripheral speed between the outer peripheral portion and the inner peripheral portion of the polishing plane 32 of the wrap 36, the lap 36 rotates in the same direction as the broken line indicated by the arrow. Similarly, the work material 56 and 57
Performs planetary motion that revolves and rotates relatively to. That is, the end surfaces of the work materials 56 and 57 on the polishing plane 32 side are pressed against the polishing plane 32, respectively.
It can be moved in the circumferential direction on 32. As described above, the correction rings 42 and 48, the flat grinding wheel 30, the work material 56
Due to the relative sliding movement of the surface grinding wheel 30 and the surface grinding wheel 30, a highly accurate plane polishing finish is applied to the processing surfaces of the workpieces 56 and 57. It should be noted that, in FIG.
Has been omitted.

As described above, according to the present embodiment, since the polishing plane 32 of the lap 36 is formed of the highly rigid flat polishing wheel 30, the conventional loose abrasive using the lap having a soft material on the lap surface is used. Compared with the lapping method, the surface polishing grindstone 30 is not deformed, so that no edge sagging or the like occurs and the processing accuracy in the plane polishing is sufficiently obtained. Table 1 shows comparison results between the lapping method A of the present embodiment using the flat grinding wheel 30 and the correction ring 48, and the conventional planetary abrasive lapping method B using the soft wrap and slurry-like polishing liquid. 4 shows data of the processing accuracy and the processing efficiency.

Further, since the surface polishing grindstone 30 is formed as having a higher hardness than the grindstone portions 40 and 46, wear during polishing is suitably suppressed, and a high flatness is maintained. For this reason, the work materials 56 and 57 can be processed to have a better flatness.

In addition, the planar polishing grindstone 30 is suitably regenerated by sliding contact between the polishing plane 32 and the correction surfaces 39 and 45 of the grindstone portions 40 and 46, and the polishing plane 32 is always maintained in a good polished state. Therefore, clogging and crushing are eliminated, and sufficient polishing efficiency can be obtained. In addition, since the abrasive grains dropped from the flat polishing grindstone 30 and the correction rings 42 and 48 by crushing due to collision between the abrasive grains due to the above-mentioned sliding contact are appropriately supplied as free abrasive grains to the polishing plane 32 and participate in the polishing, Polishing efficiency is further enhanced. Further, the abrasive grains released by crushing or the like from the grindstone portions 40 and 46 have a relatively small diameter, and are captured by the unevenness of the polishing plane 32 of the flat polishing grindstone 30 to be polished in a state where the rolling thereof is suitably suppressed. As a result, compared to the free abrasive grain method using a metal wrap, scratches caused by rolling of the free abrasive grains are prevented, and an extremely smooth polished surface is obtained.

FIG. 5 shows a conventional abrasive lapping method, the above-mentioned free abrasive lapping method B, a fixed abrasive lapping method and a fixed abrasive lapping method C using water as a polishing liquid, and a slurry-like polishing liquid applied to the abrasive fixing lap. And three types of combination method D for supplying
5 shows the results of a comparative experiment on the polishing efficiency of the lapping method A 'of the present invention. As is clear from this graph, according to the present lapping method, a remarkable improvement in the polishing efficiency of about 2 to 3 times is observed as compared with each conventional lapping method.

Also, grid-shaped grooves are formed on the polishing plane 32 of the plane polishing grindstone 30.
Since the grooves 33 are formed radially in the circumferential direction on the correction surface 45 of the grinding wheel portion 33, the loose abrasive grains generated by the sliding contact are preferably captured on the polishing plane 32 and uniformly. Are distributed. For this reason, the free abrasive grains effectively function as cutting edges, and partial polishing of the workpieces 56 and 57 is suppressed, so that a more excellent planar polishing finish in terms of flatness and efficiency can be provided.

Further, as described above, since a good cutting blade always projects on the polishing plane 32 of the plane polishing grindstone 30, it is not necessary to supply a slurry-like polishing liquid containing free abrasive grains. For this reason, it is possible to perform highly efficient polishing only by supplying pure water as a polishing liquid, and there is an advantage that management in the polishing process is facilitated.

As mentioned above, although one Example of this invention was described based on drawing, this invention is applied also in another aspect.

For example, although the surface polishing grindstone 30 of the above-described embodiment contains cerium oxide as an abrasive, other abrasives such as diamond, aluminum oxide, and silicon carbide may be used as abrasives.

In addition, the surface polishing grindstone 30 and the grindstone portion of the above-described embodiment are used.
In 46, lattice-shaped and radial grooves were respectively formed, but grooves of other shapes may be formed,
Moreover, even if no groove is formed, the primal effect of the present invention can be obtained.

Further, the grinding wheel portion 40 of the above-described embodiment is constituted by a plurality of disk-shaped pellets 40a, but the shape of the pellets can be variously changed.

Further, in the above-described embodiment, two types of correction rings, that is, the correction ring 42 having the grindstone portion 40 composed of the pellet 40a and the correction ring 48 having the grindstone portion 46 are used. Only one of 42 or 48 may be used.

The lapping device 10 of the above-described embodiment has two correction rings (42 and 48) and two weight discs corresponding to the pressing members.
(50 and 51), but three or more correction rings may be provided, or one correction ring may be provided. At this time, the pressing members may be provided in the same number as the number of the correction rings so that the work material is processed on the inner periphery of all the correction rings. Without having the cutting material in the annular space,
There may be a correction ring that only modifies the polishing plane 32 of the wrap 36.

Further, in the above-described embodiment, water was used as the polishing liquid, but a slurry containing free abrasive grains may be used as the polishing liquid.

The above is merely an embodiment of the present invention, and the present invention can be variously modified without departing from the gist thereof.

[Brief description of the drawings]

FIG. 1 is a front view in which a part of a wrapping device of the present invention is cut away. FIG. 2 is a view for explaining flat polishing finish of a hard and brittle material by a lapping device. 3 and 4 are perspective views of the correction ring. FIG. 3 is a correction ring in which a groove is formed in a grindstone portion, and FIG. 4 is a correction ring in which the grindstone portion is formed of a pellet. is there. FIG. 5 is a graph comparing the polishing efficiency between the conventional lapping method and the lapping method of the present invention. 10 Lapping device 30 Planar grinding wheel (first polishing member) 32 Polishing plane 36 Lapping 39 Modified surface 45 Modified surface 40 Grindstone portion (second polishing member) 40a: Pellet …… Whetstone part (second polishing member) 46 …… Whetstone part (second polishing member) 42 …… Correcting ring 48 …… Correcting ring 50 …… Plumbing (pressing member) 51 …… Plumbing (pressing member)

Claims (2)

(57) [Claims] 1. A hard brittle material lapping method for subjecting a member to be polished made of hard brittle material to a planar polishing finish, comprising: a lap provided with a first grindstone portion having abrasive grains fixed by a binder on a polishing surface. An annular correction ring having a second abrasive part fixed to the abrasive grains with a binder and having a second abrasive part having a lower hardness than the first abrasive part, provided on a correction surface abutting on the polishing plane, around a central axis of the wrap. A method for lapping hard and brittle material, wherein the member to be polished is subjected to planar polishing by pressing the member to be polished against the polishing surface while rotating the correction ring relatively and rotating the ring. 2. A hard brittle material lapping method for subjecting a member to be polished made of hard brittle material to planar polishing finish, wherein a first grindstone portion having abrasive grains fixed by a binder is provided on a polishing plane, and a center axis is provided. A lap that is driven to rotate around the lap, a second grindstone portion having a fixed abrasive grain and having a lower hardness than the first grindstone portion is provided on a correction surface abutting on the polishing plane, and the correction surface is the polishing surface. An annular correction ring that rotates around a central axis for fixing the position while being in contact with the flat surface, and is fitted into the correction ring to press the member to be polished toward the polishing surface of the wrap. A hard brittle material wrapping device, comprising: a pressing member.