U.S. patent application number 14/910059 was filed with the patent office on 2016-06-16 for polishing tool and processing method for member.
This patent application is currently assigned to FUJIMI INCORPORATED. The applicant listed for this patent is FUJIMI INCORPORATED. Invention is credited to Hiroshi ASANO, Yuuichi ITOU, Hitoshi MORINAGA, Shingo OTSUKI, Souma TAGUCHI, Kazusei TAMAI.
Application Number | 20160167192 14/910059 |
Document ID | / |
Family ID | 52461413 |
Filed Date | 2016-06-16 |
United States Patent
Application |
20160167192 |
Kind Code |
A1 |
OTSUKI; Shingo ; et
al. |
June 16, 2016 |
POLISHING TOOL AND PROCESSING METHOD FOR MEMBER
Abstract
The present invention relates to a polishing method using a
polishing tool provided with a polishing pad including a polishing
surface shaped in conformance with a curved surface of an object to
be polished to efficiently and uniformly polish the curved surface
of the object. A polishing tool of the present invention is
provided with a polishing pad including a polishing surface shaped
in conformance with a curved surface of an object to be polished to
uniformly contact the curved surface of the object. The polishing
pad preferably has a Shore A hardness of 5 or greater. A polishing
method of the present invention uses a polishing tool including a
polishing surface shaped in conformance with a curved surface of an
object to be polished to uniformly contact the curved surface of
the object and polish the curved surface of the object.
Inventors: |
OTSUKI; Shingo; (Kiyosu-shi,
JP) ; MORINAGA; Hitoshi; (Kiyosu-shi, JP) ;
TAMAI; Kazusei; (Kiyosu-shi, JP) ; ASANO;
Hiroshi; (Kiyosu-shi, JP) ; ITOU; Yuuichi;
(Kiyosu-shi, JP) ; TAGUCHI; Souma; (Kiyosu-shi,
JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
FUJIMI INCORPORATED |
Aichi |
|
JP |
|
|
Assignee: |
FUJIMI INCORPORATED
Kiyosu-shi, Aichi
JP
|
Family ID: |
52461413 |
Appl. No.: |
14/910059 |
Filed: |
August 6, 2014 |
PCT Filed: |
August 6, 2014 |
PCT NO: |
PCT/JP2014/070712 |
371 Date: |
February 4, 2016 |
Current U.S.
Class: |
451/28 ;
451/246 |
Current CPC
Class: |
B24B 37/20 20130101;
B24B 37/11 20130101; B24B 9/065 20130101 |
International
Class: |
B24B 37/20 20060101
B24B037/20 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 9, 2013 |
JP |
2013-167116 |
Claims
1. A polishing tool comprising a polishing pad including a
polishing surface shaped in conformance with a curved surface of an
object to be polished to uniformly contact the curved surface of
the object.
2. The polishing tool according to claim 1, wherein the polishing
tool is disk-shaped and has a diameter of 20 mm or larger.
3. The polishing tool according to claim 1, wherein the polishing
pad has a Shore A hardness of 5 or greater.
4. A processing method comprising: by using a polishing tool
provided with a polishing pad including a polishing surface shaped
in conformance with a curved surface of an object to be polished to
uniformly contact the curved surface of the object, pressing the
polishing pad against the curved surface of the object; and
polishing the curved surface of the object by rotating the
polishing tool while feeding a polishing liquid to a portion of
contact between the polishing pad and the object.
5. The processing method according to claim 4, wherein the
polishing tool is disk-shaped and has a diameter of 20 mm or
larger, the method further comprising controlling a rotation speed
of the polishing tool and reducing centrifugal force acting on the
polishing surface to reduce dispersion of the polishing liquid.
6. The processing method according to claim 4, wherein the
polishing pad has a surface including abrasive grains.
7. A method for polishing an object with a polishing tool, the
method comprising: attaching the polishing tool and/or the object
to be polished to a polishing device that includes a pressure
controller; measuring a contact pressure at a portion of contact
between a curved surface of the object and a surface of the
polishing tool; and controlling a polishing pressure and a shape of
a polishing portion in the polishing tool so that the contact
pressure is uniform.
Description
TECHNICAL FIELD
[0001] The present invention relates to a method for polishing an
object having a certain edge shape and, more particularly, to a
polishing method using a rotating polishing tool that holds a
polishing pad shaped to efficiently and uniformly polish a curved
edge of an object to be polished.
BACKGROUND ART
[0002] Generally, a polishing method using a rotating polishing
tool that holds a polishing pad includes pressing the rotating
polishing tool against the edge of an object to be polished in
contact with the object to polish the surface of contact. For
example, the edge of a silicon wafer is polished by pressing the
silicon wafer at a certain angle to form a chamfered portion (refer
to, for example, patent documents 1 and 2).
PRIOR ART DOCUMENTS
Patent Documents
[0003] Patent Document 1: Japanese Laid-Open Patent Publication No.
11-188590 [0004] Patent Document 2: Japanese Laid-Open Patent
Publication No. 2001-205549
SUMMARY OF THE INVENTION
Problems that are to be Solved by the Invention
[0005] However, to polish the edge of an object to be polished, the
position and angle of contact with the polishing tool needs to be
adjusted in conformance with the shape of the object. In
particular, when polishing the edge into a curved surface, the
position and angle of the object to be polished needs to be
adjusted and entirely be finished as a curved surface. Thus, the
polishing requires skill, and the polishing time is longer compared
to normal planar polishing.
[0006] Further, the number of objects that can be polished at the
same time is limited in the conventional method. This lengthens the
polishing time, which is not constant, and causes the polishing to
be inefficient.
[0007] Thus, there is a demand for a rotating polishing tool and
method that uniformly and efficiently polishes a curved edge of an
object to be polished.
Means for Solving the Problem
[0008] The inventors of the present invention have studied the
above problem and completed the present invention. More
specifically, the present invention relates to a polishing method
including pressing a polishing tool, which is provided with a
polishing pad including a polishing surface shaped in conformance
with a curved surface of an object to be polished to uniformly
contact the curved surface of the object, against the curved
surface of the object and polishing the curved surface of the
object by feeding a polishing liquid to the pressed portion and
moving the polishing pad relative to the object. This allows the
curved surface of the object to be uniformly polished.
[0009] To achieve the above objective, one aspect of the present
invention provides a polishing tool provided with a polishing pad
including a polishing surface shaped in conformance with a curved
surface of an object to be polished to uniformly contact the curved
surface of the object.
[0010] It is preferred that the polishing tool be disk-shaped and
have a diameter of 20 mm or larger, and that the polishing pad have
a Shore A hardness of 5 or greater.
[0011] A further aspect of the present invention provides a
processing method including, by using a polishing tool provided
with a polishing pad including a polishing surface shaped in
conformance with a curved surface of an object to be polished to
uniformly contact the curved surface of the object, pressing the
polishing pad against the curved surface of the object, and
polishing the curved surface of the object by rotating the
polishing tool while feeding a polishing liquid to a portion of
contact between the polishing pad and the object. It is preferred
that the polishing tool be disk-shaped and have a diameter of 20 mm
or larger, and that the method further include controlling a
rotation speed of the polishing tool and reducing centrifugal force
acting on the polishing surface to reduce dispersion of the
polishing liquid.
[0012] A further aspect of the present invention provides a method
for polishing an object with a polishing device that includes a
pressure controller. The method includes measuring a contact
pressure at a portion of contact between a curved surface of the
object and a surface of a polishing tool, and controlling a
polishing pressure and a shape of a polishing portion in the
polishing tool so that the contact pressure is uniform.
Effects of the Invention
[0013] The present invention succeeds in efficiently and uniformly
polishing a curved surface of an object to be polished with a
polishing tool that includes a polishing pad.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a diagram showing one example of the shape of a
polishing pad.
[0015] FIG. 2 is a diagram showing one example of the shape of a
polishing pad. Grooves are formed to feed a polishing liquid from
the center of the pad. Two identically shaped pads are prepared,
and the two pads are combined for use.
[0016] FIG. 3 is a diagram showing one example of a polishing pad.
Bores are formed in the central portion of the pad to feed a
polishing liquid.
[0017] FIG. 4 is a diagram showing one example of the shape of a
polishing pad. The pad of FIG. 2 is combined with the pad of FIG.
3.
[0018] FIG. 5 is a diagram showing one example of a polishing
device.
[0019] FIG. 6 is a diagram showing one example of a polishing
device.
[0020] FIG. 7 is a diagram showing one example of a polishing
device. This example is provided with a polishing liquid feeding
unit.
[0021] FIG. 8 is a diagram showing one example of a polishing
device. This example is provided with a pressure sensor or a device
that functions in the same manner as the pressure sensor.
[0022] FIG. 9 is a partial side view showing a modified example of
a polishing tool, which includes a polishing pad, and an object to
be polished.
[0023] FIG. 10 is a partial side view showing a modified example of
a polishing tool, which includes a polishing pad, and an object to
be polished.
[0024] FIG. 11 is a partial side view showing a modified example of
a polishing tool, which includes a polishing pad, and an object to
be polished.
[0025] FIG. 12 is a partial side view showing a modified example of
a polishing tool, which includes a polishing pad, and an object to
be polished.
[0026] FIG. 13 is a partial side view showing one example of a
polishing tool that is modified in shape.
[0027] FIG. 14 is a partial side view showing one example of a
polishing tool that is modified in shape.
MODES FOR CARRYING OUT THE INVENTION
[0028] One embodiment of the present invention will now be
described.
[0029] A polishing tool of the present embodiment has a feature in
that the polishing tool is provided with a polishing pad including
a polishing surface shaped in conformance with a curved surface of
an object to be polished (workpiece to be polished) to uniformly
contact the curved surface of the object (refer to FIG. 1). The
polishing tool of the present embodiment has a feature in that the
polishing tool is shaped in conformance with a curved surface of an
object to be polished to uniformly contact the curved surface of
the object.
[0030] An object to be polished used in the present embodiment
includes a curved surface. The curved surface of the object shows a
curved line in a cross-section orthogonal to a surface to be
polished of the object. Further, the shape of the curved line is
identical or similar in the cross-section at a number of locations
on the surface to be polished. A polishing tool including a
polishing surface shaped in conformance with a curved surface of an
object to be polished may be used to polish the object. This
results in uniform contact of the curved surface of the object with
the polishing surface of the polishing tool and allows for uniform
polishing. The curved line in the cross-section of the surface to
be polished of the object may have any shape. The curved line may
be an arc or a combination of arcs and partially include a straight
portion. For example, the curved surface of the object to be
polished may be bulged toward the outer side of the object (refer
to example shown in FIG. 9) or recessed toward the inner side of
the object (refer to example shown in FIG. 10). Further, the object
to be polished may include a surface to be polished having a
generally triangular cross-section with a rounded peak (refer to
example shown in FIG. 11) or a generally stepped shape with rounded
corners (refer to example shown in FIG. 12). Even when the surface
to be polished of the object to be polished is a curved surface
having one of the above shapes, the use of a polishing tool
including a polishing surface shaped in conformance with the curved
surface of the object to polish the object results in uniform
contact of the curved surface of the object with the polishing
surface of the polishing tool and allows for uniform polishing.
[0031] The polishing tool of the present embodiment has a feature
in that the polishing tool is provided with a polishing pad that
includes a polishing surface shaped in conformance with a curved
surface of an object to be polished. The polishing pad of the
present embodiment need only be located on the edge or the
periphery of the polishing tool. The polishing pad may be adhered
to the periphery of the polishing tool, coupled to the periphery of
the polishing tool, or molded in any manner on the periphery of the
polishing tool. Alternatively, the polishing tool may be molded as
the polishing pad. There is no particular restriction to the
material of the polishing tool except for the polishing portion
(polishing pad), and a resin, a metal, or a ceramic may be used.
Alternatively, a mixture of a plurality of materials may be used.
For example, when a resin is used as the material of the polishing
tool, any synthetic resin may be used. Examples of such a synthetic
resin include a thermosetting resin (such as phenol resin, epoxy
resin, urethane resin, and polyimide) and a thermoplastic resin
(such as polyethylene, polypropylene, acrylic resin, polyamide, and
polycarbonate). When a metal is used as the material of the
polishing tool, magnesium, aluminum, titanium, iron, nickel, cobalt
copper, zinc, manganese, or an alloy of which the main component is
any of these metals may be used. When a ceramic is used as the
material of the polishing tool, any of ceramics and glass; any of
an oxide, nitride, boride, and carbide of silicon, aluminum,
zirconium, calcium, and barium; or any of aluminum oxide, zirconium
oxide, silicon oxide, silicon carbide, silicon nitride, and boron
nitride may be used.
[0032] Further, any material may be used for the object to be
polished. For example, when using a resin, any synthetic resin may
be used. Examples of such a synthetic resin include a thermosetting
resin (such as phenol resin, epoxy resin, urethane resin, and
polyimide) and a thermoplastic resin (such as polyethylene,
polypropylene, acrylic resin, polyamide, and polycarbonate). When a
ceramic is used as the material of the object to be polished, any
of ceramics, glass, and fine ceramics; any of an oxide, carbide,
nitride, and boride of silicon, aluminum, zirconium, calcium, and
barium may be used. When a metal is used as the material of the
object to be polished, magnesium, aluminum, titanium, iron, nickel,
cobalt, copper, zinc, manganese, or an alloy of which the main
component is any of these metals may be used. The object to be
polished may be used for any purpose. For example, the object to be
polished may be used as a wheel, a shaft, a container, a casing
(for example, case and housing), a frame, a ball, a wire, an
ornament, or the like.
[0033] It is preferred that the polishing tool be disk-shaped and
have a diameter of 20 mm or larger. When the polishing tool has a
large size, a high linear velocity is obtained even when the
rotation speed is the same. Thus, there is no need for the rotation
speed of the polishing tool to be high when performing polishing.
Further, the centrifugal force applied to the polishing surface by
the rotation can be reduced. This limits the dispersion of the
polishing liquid. The size of the polishing tool is preferably 30
mm or larger in diameter, and more preferably 50 mm or larger in
diameter.
[0034] Further, the size of the polishing tool is preferably 1,000
mm in diameter or smaller, and more preferably 400 mm or smaller.
When the diameter of the polishing tool is 1,000 mm and the
rotation speed is 80 rpm, a linear velocity of 300 m/min is
obtained. A polishing tool having a larger diameter obtains a
higher linear velocity with a small rotation speed, further reduces
the centrifugal force acting on the polishing surface, and limits
the dispersion of the polishing liquid. When the size of the
polishing tool is too large, the polishing device is enlarged and
becomes noneconomic. Thus, from an economic viewpoint, it is
preferred that the size of the polishing tool be 1,000 mm or
smaller in diameter.
[0035] Depending on the polishing method or the specification of
the polishing device, the polishing tool may be larger when, for
example, the device polishes a plurality of objects with a single
polishing tool. When a plurality of objects are polished at the
same time, the processing efficiency increases, and the number of
polishing devices required for polishing can be decreased.
[0036] The polishing pad in the polishing tool of the present
embodiment has a Shore A hardness of 5 or greater. When a polishing
pad having a Shore A hardness of 5 or greater, which is subject to
hardness measurement, is left for 60 minutes or longer in a dry
condition where the humidity is 20% to 60% under room temperature,
the hardness of the polishing pad is then measured with a durometer
(type A) that is compliance with JIS K6253, and the measured value
is 5 or greater. When the Shore A hardness of the polishing pad is
5 or greater, the surface of the object to be polished can be
polished in a preferred manner. Further, deformation of the surface
of the polishing pad can be reduced that would be caused by
polishing performed within a short period of time.
[0037] The polishing tool of the present embodiment has a feature
in that the material of the polishing pad is at least one of a
cloth, a non-woven fabric, a resin processed non-woven fabric,
synthetic leather, synthetic resin foam, and a composite thereof.
The polishing pad may include abrasive grains. When using a pad
including abrasive grains, the type of the used abrasive grains is
not particularly limited and may be metal oxide particles of
silicon oxide, aluminum oxide, zirconium oxide, cerium oxide,
magnesium oxide, calcium oxide, titanium oxide, manganese oxide,
iron oxide, or chromium oxide; a carbide, such as silicon carbide;
a nitride; a boride; or a diamond.
[0038] The polishing method of the present embodiment is performed
by using a polishing tool provided with a polishing pad including a
polishing surface shaped in conformance with a curved surface of an
object to be polished to uniformly contact the curved surface of
the object, pressing the polishing pad against the curved surface
of the object, and polishing the curved surface of the object by
rotating the polishing tool while feeding a polishing liquid to a
portion of contact between the polishing pad and the object.
[0039] The polishing method of the present embodiment has a feature
in that a polishing liquid is fed to the portion of contact between
the polishing pad and the object to be polished. The polishing
liquid may be fed by directly feeding the polishing liquid to the
portion of contact from the outer side. Depending on the structure
of the polishing device, for example, a polishing liquid feeding
mechanism such as a rotary joint may be arranged at a connection
portion of the polishing tool to directly feed a polishing liquid
(processing liquid) to the polishing portion from the inside of the
polishing tool (refer to FIGS. 2 to 4 and 7). The feeding
efficiency of the polishing liquid can be further increased by
feeding the polishing liquid from the inside.
[0040] To efficiently use the polishing liquid, it is further
preferable that a cover be arranged around the rotating polishing
tool and that a recovery device be provided to increase the
recovery efficiency of the polishing liquid.
[0041] The polishing liquid may have a known composition used for
polishing, lapping, or machining. The polishing liquid may be
aqueous based, oil based, or ether based. Further, when necessary,
an additive such as a pH adjuster, an etching agent, an oxidant, a
complexing agent, a surfactant, an emulsifier, an antioxidant, an
anticorrosive, a protective film forming agent, a thickener, a
stabilizing agent, a dispersant, an antiseptic, and a fungicide may
be used. Abrasive grains may further be added to the polishing
liquid. The type of abrasive grains used for the polishing liquid
is not particularly limited and may be metal oxide particles of
silicon oxide, aluminum oxide, zirconium oxide, cerium oxide,
magnesium oxide, calcium oxide, titanium oxide, manganese oxide,
iron oxide, or chromium oxide; a carbide, such as silicon carbide;
a nitride; a boride; or a diamond. Further, organic particles
using, for example, thermoplastic resin may be used.
[0042] It is preferred that the linear velocity during the
polishing be 10 m/min or higher. When the linear velocity is 10
m/min or higher, the edge of the object to be polished may be
efficiently polished.
[0043] The rotation speed of the polishing tool during the
polishing is preferably 5,000 rpm or lower, and more preferably
2,000 rpm or lower. When the polishing tool is rotated at a high
speed of 5,000 rpm or higher, the centrifugal force acting on the
polishing surface disperses the polishing liquid. Thus, to continue
polishing, the polishing liquid needs to be replenished to make up
for the dispersed amount. Thus, to hold the polishing liquid in the
polishing tool in a suitable manner and perform stably polishing,
the preferred rotation speed is 5,000 rpm or lower.
[0044] The processing method of the present embodiment attaches a
polishing tool to a certain polishing device to use the polishing
tool. As long as the polishing device includes a mechanism that can
hold and rotate the polishing tool, the polishing device is not
particularly limited and may be, for example, a known polishing
device. Examples of the polishing device include grinding devices
such as a cylindrical grinder, a bench grinder, and a grinder. The
relative positions of the polishing tool and the object to be
polished need to be set so that the curved surface of the object
can be polished. However, there may be any positional relationship.
For example, the polishing tool may be supported horizontally
(refer to FIG. 6) or vertically (refer to FIG. 5) and be pressed
from any direction against the object to be polished to perform
polishing. In the polishing method of the present embodiment, a jig
is used to fix the object to be polished at a certain angle and
position. The jig is preferably movable and preferably able to
sequentially perform polishing while moving the edge of the object
to be polished.
[0045] The polishing method of the present embodiment is performed
by attaching a polishing tool and/or an object to be polished to a
polishing device that includes a pressure controller when polishing
the object with the polishing tool, measuring the contact pressure
at a portion of contact between a curved surface of the object and
a surface of the polishing tool, and controlling the polishing
pressure and the shape of the polishing portion in the polishing
tool so that the contact pressure is uniform. To perform further
uniform and accurate polishing, a pressure sensor or a device that
functions in the same manner as the pressure sensor, namely, a
pressure controller, is attached to the rotation shaft of the
object to be polished, the rotation shaft of the polishing tool, or
the polishing tool. The pressure at the portion of contact between
the curved surface of the object to be polished and the polishing
tool surface is measured and the distribution and change of the
contact pressure are measured to control the polishing pressure and
the shape of the polishing portion in the polishing tool during
polishing. This keeps the polishing accuracy and the polishing
efficiency constant and allows the timing for replacing the
polishing tool to be checked (refer to FIG. 8).
[0046] FIGS. 13 and 14 show a modified example of the present
embodiment. In the modified example shown in FIG. 13, the polishing
tool 10 includes a polishing pad formed from the material described
above, more specifically, a material that elastically deforms and
has a certain degree of elasticity. A polishing surface 11 has a
width H1 in a direction parallel to the rotation axis of the
polishing tool 10 (direction of arrow Y in FIG. 13) that is smaller
by a predetermined amount .alpha. than the thickness T1 of the
object to be polished K (i.e., distance between upper surface KU
and lower surface KD of object to be polished K) prior to
polishing. In this manner, the polishing pad is formed from an
elastic body, and the polishing surface 11 of the polishing pad is
shaped to be smaller than the shape of the portion to be polished
in the object K. This example has the advantages described
below.
[0047] As shown in FIG. 14, in this modified example, when the
polishing tool 10 is rotated and the object to be polished K is
pressed against the polishing surface 11, the polishing pad, which
is elastically deformed by the predetermined amount .alpha.,
applies a pressing force F to the upper surface KU and the lower
surface KD of the object to be polished K. This is advantageous in
that when polishing the object to be polished K, in addition to the
edge KE, which has a curved surface, the upper surface KU and the
lower surface KD are simultaneously polished. When the
predetermined amount .alpha. is increased, the elastic deformation
amount of the polishing pad increases when polishing the object to
be polished K. Thus, the pressing force F applied to the upper
surface KU and the lower surface KD of the object to be polished K
may be optimized by optimizing the predetermined amount
.alpha..
[0048] The force for pressing the edge KE of the object to be
polished K against the polishing surface 11 and the pressing force
F applied to the upper surface KU and the lower surface KD of the
object to be polished K may be adjusted when necessary to properly
polish the object K.
[0049] As described above, when molding the polishing tool as the
polishing pad, the polishing tool 10 is formed of a material like a
resin that elastically deforms and has a certain degree of
elasticity. Further, in the same manner as the modified example
shown in FIG. 13, the width H1 of the polishing surface 11 in the
polishing tool 10 is smaller by a predetermined amount .alpha. than
the thickness T1 of the object to be polished K prior to polishing.
In this manner, when the polishing tool 10, which functions as a
polishing pad, is formed by an elastic body, and the polishing
surface 11 of the polishing tool 10 is shaped to be smaller than
the portion to be polished in the object to be polished K,
advantages similar to those of the modified example shown in FIG.
13 can be obtained.
INDUSTRIAL APPLICABILITY
[0050] As described above, the present invention is effective as a
polishing tool and a polishing method for accurately polishing a
curved surface of an object to be polished. In particular, the
present invention allows a curved surface of an object to be
polished with high accuracy. Further, the present invention is more
efficient than the conventional method.
DESCRIPTION OF THE REFERENCE CHARACTERS
[0051] 10: polishing tool, 11: polishing surface, K: object to be
polished, KE: edge (of object to be polished), KU: upper surface
(of object to be polished), KD: lower surface (of object to be
polished).
* * * * *