U.S. patent application number 10/937685 was filed with the patent office on 2005-02-10 for method of cleaning abrasive plates of abrasive machine and cleaning device.
This patent application is currently assigned to Fujikoshi Machinery Corp.. Invention is credited to Denda, Yasuhide, Hasegawa, Tsuyoshi, Moriya, Norihiko, Nakajima, Makoto, Nakamura, Yoshio, Nishimoto, Yoshinobu.
Application Number | 20050028843 10/937685 |
Document ID | / |
Family ID | 18816542 |
Filed Date | 2005-02-10 |
United States Patent
Application |
20050028843 |
Kind Code |
A1 |
Denda, Yasuhide ; et
al. |
February 10, 2005 |
Method of cleaning abrasive plates of abrasive machine and cleaning
device
Abstract
The method of the present invention cleans abrasive faces of an
upper abrasive plate and a lower abrasive plate of an abrasive
machine. The method is executed by a cleaning device including: a
nozzle for jetting water; a brush for preventing the jetted water
from scattering in the air, the brush enclosing the nozzle; and
another brush for closing a gap between the preventing brush and an
outer edge of the upper abrasive plate, the method is characterized
by the steps of: jetting water from the nozzle toward the abrasive
face of the upper abrasive plate; moving the nozzle toward the
outer edge of the upper abrasive plate; and closing the gap by the
closing brush when the gap is formed between the preventing brush
and the outer edge of the upper abrasive plate.
Inventors: |
Denda, Yasuhide;
(Nagano-shi, JP) ; Nakamura, Yoshio; (Nagano-shi,
JP) ; Nishimoto, Yoshinobu; (Nagano-shi, JP) ;
Nakajima, Makoto; (Nagano-shi, JP) ; Hasegawa,
Tsuyoshi; (Nagano-shi, JP) ; Moriya, Norihiko;
(Nagano-shi, JP) |
Correspondence
Address: |
JORDAN AND HAMBURG LLP
122 EAST 42ND STREET
SUITE 4000
NEW YORK
NY
10168
US
|
Assignee: |
Fujikoshi Machinery Corp.
Nagano-shi
JP
|
Family ID: |
18816542 |
Appl. No.: |
10/937685 |
Filed: |
September 9, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10937685 |
Sep 9, 2004 |
|
|
|
09992191 |
Nov 6, 2001 |
|
|
|
6807701 |
|
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Current U.S.
Class: |
134/37 |
Current CPC
Class: |
B24B 37/08 20130101;
B08B 2203/0229 20130101; Y10S 134/902 20130101; B24B 53/017
20130101; B08B 3/024 20130101; B08B 15/04 20130101 |
Class at
Publication: |
134/037 |
International
Class: |
B24B 049/00 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 9, 2000 |
JP |
2000-341885 |
Claims
What is claimed is:
1. A method of cleaning abrasive faces of an upper abrasive plate
and a lower abrasive plate of an abrasive machine, which are
mutually faced, by a cleaning device including: a pivotable nozzle
for jetting water toward the abrasive faces of said abrasive plates
rotating; means for pivoting said nozzle; and means for moving said
nozzle along the abrasive faces, said method is characterized by
the steps of: jetting water from said nozzle toward the abrasive
face of said upper abrasive plate; moving said nozzle so as to
clean the abrasive face of said upper abrasive plate; pivoting said
nozzle toward the abrasive face of said lower abrasive plate;
jetting water from said nozzle toward the abrasive face of said
lower abrasive plate; and moving said nozzle so as to clean the
abrasive face of said lower abrasive plate.
2. The method according to claim 1, wherein said cleaning device
further includes an enclosing member enclosing a space including
said abrasive plates so as to prevent water jetted from said nozzle
from scattering outside of said cleaning device.
3. The method according to claim 1, wherein said cleaning device
further includes means for preventing the jetted water from
scattering in the air, which is provided around said nozzle, and
wherein the upper abrasive face of said lower abrasive plate is
cleaned by jetting water into a space formed by the upper abrasive
face of said lower abrasive plate and said preventing means, after
the lower abrasive face of said upper abrasive plate is cleaned by
jetting water into a space formed by the lower abrasive face of
said upper abrasive plate and said preventing means.
4. The method according to claim 3, wherein said preventing means
is a brush.
5. The method according to claim 1, wherein width and density of
discharging grooves, which discharge abraded dusts and slurry
outside, of said upper abrasive plate are different from those of
said lower abrasive plate, and wherein moving speed of said nozzle
for cleaning the abrasive face of said upper abrasive plate and
that for cleaning the abrasive face of said lower abrasive plate
are independently controlled.
6. The method according to claim 1, wherein a plurality of nozzles,
which are capable of jetting water in the same direction, are
linearly arranged, and they are capable of simultaneously pivoting
toward the same direction and simultaneously moving in the same
direction with respect to the abrasive faces of said abrasive
plates.
7. The method according to claim 1, wherein pressure of water
supplied to said nozzle is 10.79 MPa or more.
Description
REFERENCE TO RELATED SPECIFICATION
[0001] This is a divisional application of application Ser. No.
09/992,191, filed Nov. 6, 2001.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to a method of cleaning
abrasive plates of an abrasive machine and a cleaning device, more
precisely relates to a method, in which abrasive faces of an upper
abrasive plates and a lower abrasive plates, which are mutually
faced and rotated, are cleaned by water jetted from a nozzle moving
along the abrasive faces, and a cleaning device executing said
method.
[0003] Both side faces of a wafer-shaped work piece, e.g., silicon
wafer, are abraded by an abrasive machine. A lapping machine, which
is a kind of abrasive machines, is shown in FIG. 10.
[0004] In FIG. 10, the lapping machine has an upper abrasive plate
20, whose lower face is an abrasive face for lapping work pieces
10, e.g., silicon wafers, and keys 21 are keyed in an upper face of
the upper abrasive plate 20. An air cylinder unit 22 is provided
above the upper abrasive plate 20. The air cylinder unit 22 is
fixed to an upper part of a gate-shaped frame 14. The upper
abrasive plate 20 is rotatably connected to a lower end of a piston
rod 22a of the air cylinder unit 22 by a rotary plate 23 and
connecting rods 27. By employing a connector 22b, the piston rod
22a cannot rotate; the rotary plate 23 and the upper abrasive plate
20, which are connected by the connecting rods 27, can be rotated
with respect to the piston rod 22a and held at the lower end
thereof. With this structure, weight or a pressing force of the
upper abrasive plate 20, which works to a lower abrasive plate 30,
can be controlled by adjusting a lifting force of the cylinder unit
22.
[0005] Note that, in some cases, the pressing force working to the
lower abrasive plate 30 is controlled by adjusting a pressing force
applied to the upper abrasive plate 20.
[0006] Since the keys 21 engage with key grooves of a rotary member
54 which is rotated by a motor 70, the upper abrasive plate 20 is
rotated by a driving force of the motor 70. A shaft 54a is
downwardly extended from the rotary member 54. A gear 54b, which is
fixed to a lower end of the shaft 54a, is engaged with an idle gear
63, and the idle gear 63 is engaged with a gear 64, which is fixed
to a spindle 60. With this structure, the driving force or torque
of the motor 70 can be transmitted to the upper abrasive plate 20
via the rotary member 54.
[0007] Since the upper abrasive plate 20 and the rotary member 54
are connected by the keys 21, a clearance between the upper
abrasive plate 20 and the lower abrasive plate 30 can be made wider
by actuating the air cylinder unit 22 when the work pieces 10 are
set or discharged or maintenance is executed.
[0008] Carriers 40 are rotated by an external gear 50 and an
internal gear 52. A first hollow shaft 50a, which is coaxial to the
shaft 54a, is connected to the external gear 50, and a gear 50b,
which is fixed to the first hollow shaft 50a, is engaged with a
gear 65 of the spindle 60.
[0009] A second hollow shaft 30a, which is coaxial to the first
hollow shaft 50a, is connected to the lower abrasive plate 30, and
a gear 30b, which is fixed to a mid part of the second hollow shaft
30a, is engaged with a gear 61 of the spindle 60.
[0010] A third hollow shaft 52a, which is coaxial to the second
hollow shaft 30a, is connected to the internal gear 52, and a gear
52b, which is fixed to the third hollow shaft 52a, is engaged with
a gear 62 of the spindle 60. The spindle 60 is connected to an
adjustable reduction unit 69, which is connected to the motor 70,
e.g., an electric motor, a hydraulic motor, by a belt.
[0011] The upper abrasive plate 20, the lower abrasive plate 30,
the external gear 50 and the internal gear 52 are rotated by one
motor 70 via the reduction unit 69, the gears and the shafts.
[0012] An upper abrasive face of the lower abrasive plate 30 has
discharging grooves 12 and 16, which run like lattice as shown in
FIG. 11, so as to discharge abraded dusts, which are produced by
abrading the work pieces 10, and slurry from the abrasive face. The
discharging grooves 12 and 16 are formed in the lower abrasive face
of the upper abrasive plate 20, too.
[0013] The abraded dusts and slurry gradually deposit in the
discharging grooves 12 and 16, and they damage surfaces of the work
pieces 10. To prevent the damage of the work pieces 10, the
clearance between the abrasive plates 20 and 30 is widen by
actuating the air cylinder unit 22 after a prescribed number of
abrasive works are completed so as to clean the abrasive faces of
the abrasive plates 20 and 30.
[0014] However, the abraded dusts and slurry are solidified in the
grooves 12 and 16 of the abrasive faces of the abrasive plates 20
and 30, so they must be manually removed. Namely, a metal plate is
manually inserted into the grooves 12 and 16 so as to scrape out
the solidified dusts from the grooves 12 and 16. It takes a long
time to completely clean the abrasive faces, and the abrasive faces
are sometimes damaged.
[0015] To automatically clean the abrasive faces, a cleaning device
was disclosed in the Japanese Patent Gazette No. 7-9342 (see FIG.
12). In the conventional cleaning device shown in FIG. 12, front
end sections of two nozzles 100a and 100b are respectively enclosed
by brush members 102. The nozzles 100a and 100b are provided to a
front end of a shaft 106 and respectively headed upward and
downward. With this structure, pressurized water is jetted upward
and downward from the nozzles 100a and 100b. The shaft 106 is
vertically and horizontally moved together with the nozzles 100a
and 100b.
[0016] In the cleaning device shown in FIG. 12, front ends of the
brush members 102 simultaneously contact the abrasive faces of the
upper abrasive plate 20 and the lower abrasive plate 30, and the
pressurized water, whose pressure is about 50-100 atm., is
simultaneously jetted from the nozzles 100a and 100b toward the
abrasive faces rotating (see FIG. 13). The nozzles 100a and 100b
are moved in the radial direction with respect to the abrasive
faces, so that abraded dusts deposited in the grooves 12 and 16 of
the abrasive faces can be removed.
[0017] The cleaning device shown in FIGS. 12 and 13 can
automatically clean the abrasive faces of the abrasive plates 20
and 30.
[0018] When the pressurized water is jetted from the nozzles 100a
and 100b toward the abrasive faces, the nozzles 100a and 100b are
respectively formed by the brush members 102 and the abrasive
faces, so that the jetted water cannot be scattered outside.
[0019] However, outer edges of the abrasive plates 20 and 30 must
be washed so as to clean the whole abrasive faces. When the nozzles
100a and 100b are moved to the outer edged of the abrasive plates
20 and 30, gaps are respectively formed between the outer edges of
the abrasive plates 20 and 30 and the brush members 102 as shown in
FIG. 14, so that the jetted water is scattered outside from the
gaps.
[0020] The water jetted outside from the gap between the outer edge
of the lower abrasive plate 30 and the brush member 102 for
cleaning the lower abrasive plate 30 is received and introduced
outside of the cleaning device via a discharging section 31a (see
FIG. 10). The discharging section 31a is formed along the outer
edge of the lower abrasive plate 30. As shown in FIG. 10, the
internal gear 52 is provided in the discharging section 31a, so a
width of the discharging section 31a is narrow. Therefore, the
water, which has once passed through the discharging section 31a,
is not returned to the abrasive face via the discharging section
31a.
[0021] On the other hand, the water jetted outside from the gap
between the outer edge of the upper abrasive plate 20 and the brush
member 102 for cleaning the upper abrasive plate 20 is scattered
into a space, in which an abrading mechanism is set.
[0022] The water, which is scattered into the space, includes the
abraded dusts and used slurry, so it makes abraded products
dirty.
[0023] Especially, the abrasive machine for abrading silicon
wafers, is located in a clean room, so the water jetted from the
nozzle 100a and scattered into the clean room via the gap of the
upper abrasive plate 20 makes degree of cleanliness of the clean
room lower.
[0024] If a moving range of the nozzles 100a and 100b is limited so
as to prevent the water jetted from the nozzle 100a from scattering
outside via the gap of the upper abrasive plate 20, the outer edge
portions of the abrasive faces of the abrasive plates 20 and 30
cannot be cleaned, and the portions must be manually cleaned.
Therefore, it is difficult to automatically clean the whole
abrasive faces of the abrasive plates 20 and 30.
[0025] Further, in the cleaning device shown in FIGS. 12 and 13,
the pressurized water is simultaneously jetted from the nozzles
100a and 100b so as to simultaneously wash the abrasive faces of
the abrasive plates 20 and 30. Therefore, the water washing the
lower abrasive face of the upper abrasive plate 20 falls onto the
upper abrasive face of the lower abrasive plate 30, so that the
upper abrasive face of the lower abrasive plate 30 is made dirty
again by the water washing the lower abrasive face of the upper
abrasive plate 20.
[0026] In the case that width and density of the discharging
grooves 12 and 16 of the upper abrasive plate 20 are different from
those of the lower abrasive plate 30, proper moving speed for
washing the upper abrasive plate 20 is different from that for
washing the lower abrasive plate 30. In the cleaning device shown
in FIGS. 12 and 13, the moving speed of the both nozzles 100a and
100b are equal, so one of the abrasive faces cannot be cleaned
properly.
SUMMARY OF THE INVENTION
[0027] A first object of the present invention is to provide a
method of cleaning abrasive plates, which is capable of cleaning
whole abrasive faces of an upper abrasive plate and a lower
abrasive plate without scattering jetted water into a space in
which an abrading mechanism is set, and a cleaning device for
executing said method.
[0028] A second object is provide to a method of cleaning abrasive
plates, which is capable of cleaning the abrasive faces of the both
abrasive plates rotating, which are mutually faced, without making
the upper abrasive face of the lower abrasive plate dirty with
water washing the lower abrasive face of the lower abrasive plate,
and a cleaning device for executing said method.
[0029] To achieve the first object, the inventors of the present
invention studied and found that scattering the jetted water into
the space in which an abrading mechanism is set can be prevented by
the steps of: moving a nozzle, which jets pressurized water and
which is formed by a brush and the abrasive face of the upper
abrasive plate, toward an outer edge of the upper abrasive plate;
and closing a gap between the outer edge of the upper abrasive
plate and the brush by another brush when the gap is formed.
[0030] Namely, the first object can be achieved by the following
method. It is a method of cleaning abrasive faces of an upper
abrasive plate and a lower abrasive plate of an abrasive machine,
which are mutually faced, by a cleaning device including:
[0031] a nozzle for jetting water toward the abrasive faces of the
abrasive plates rotating;
[0032] means for moving the nozzle along the abrasive faces;
[0033] means for preventing the jetted water from scattering in the
air, the preventing means enclosing the nozzle; and
[0034] means for closing a gap between the preventing means and an
outer edge of the upper abrasive plate,
[0035] the method is characterized by the steps of:
[0036] jetting water from the nozzle toward the abrasive face of
the upper abrasive plate;
[0037] moving the nozzle toward the outer edge of the upper
abrasive plate; and
[0038] closing the gap by the closing means when the gap is formed
between the preventing means and the outer edge of the upper
abrasive plate.
[0039] In this method, as described in BACKGROUND OF THE INVENTION,
the jetted water for cleaning the abrasive face of the lower
abrasive plate is not scattered into a space, in which an abrading
mechanism is set, even if the jetted water is jetted from the gap
between the preventing means and the outer edge of the lower
abrasive plate.
[0040] Therefore, if no water is jetted outside from the gap
between the preventing means and the outer edge of the upper
abrasive plate while cleaning the upper abrasive plate, the whole
abrasive faces of the both abrasive plates can be cleaned without
scattering water into the space in which the abrading mechanism is
set.
[0041] In the method of the present invention, the nozzle, which
jets the water toward the abrasive face of the upper abrasive plate
and which is formed by the abrasive face of the upper abrasive
plate and the preventing means, is moved toward the outer edge of
the upper abrasive plate, and the closing means closes the gap
between the preventing means and the outer edge of the upper
abrasive plate.
[0042] With this action, the whole abrasive faces of the both
abrasive plates can be cleaned without scattering water into the
space in which the abrading mechanism is set.
[0043] To achieve the second object, the inventors of the present
invention studied and found that contamination of the abrasive face
of the lower abrasive plate can be prevented by the steps of:
washing the lower abrasive face of the upper abrasive plate; and
secondly washing the upper abrasive face of the lower abrasive
plate after the upper abrasive plate is washed, whereby the water
washing the upper abrasive plate can be securely removed when the
lower abrasive plate is washed.
[0044] The second object can be achieved by the following method.
It is a method of cleaning abrasive faces of an upper abrasive
plate and a lower abrasive plate of an abrasive machine, which are
mutually faced, by a cleaning device including:
[0045] a pivotable nozzle for jetting water toward the abrasive
faces of the abrasive plates rotating;
[0046] means for pivoting the nozzle; and
[0047] means for moving the nozzle along the abrasive faces, the
method is characterized by the steps of:
[0048] jetting water from the nozzle toward the abrasive face of
the upper abrasive plate;
[0049] moving the nozzle so as to clean the abrasive face of the
upper abrasive plate;
[0050] pivoting the nozzle toward the abrasive face of the lower
abrasive plate;
[0051] jetting water from the nozzle toward the abrasive face of
the lower abrasive plate; and
[0052] moving the nozzle so as to clean the abrasive face of the
lower abrasive plate.
[0053] In this method, firstly the lower abrasive face of the upper
abrasive plate is cleaned by the water jetted from the nozzle.
Then, the nozzle is pivoted toward the upper abrasive face of the
lower abrasive plate, and the upper abrasive face of the lower
abrasive plate is cleaned by the jetted water. With this action,
the water washing the upper abrasive plate and falling onto the
upper abrasive face of the lower abrasive plate can be securely
removed when the lower abrasive plate is washed, so that the
contamination of the lower abrasive plate can be fully
prevented.
[0054] Further, in this method, width and density of discharging
grooves, which discharge abraded dusts and slurry outside, of the
upper abrasive plate may be different from those of the lower
abrasive plate, and moving speed of the nozzle for cleaning the
abrasive face of the upper abrasive plate and that for cleaning the
abrasive face of the lower abrasive plate may be independently
controlled.
BRIEF DESCRIPTION OF THE DRAWINGS
[0055] Embodiments of the present invention will now be described
by way of examples and with reference to the accompanying drawings,
in which:
[0056] FIG. 1 is a partial sectional view of an embodiment of a
cleaning device of the present invention;
[0057] FIG. 2 is an explanation view of the cleaning device shown
in FIG. 1;
[0058] FIG. 3 is an explanation view of another embodiment of the
cleaning device;
[0059] FIGS. 4A and 4B are partial front views of another nozzle of
the cleaning device shown in FIG. 3;
[0060] FIG. 5 is a partial front view of another nozzle of the
cleaning device shown in FIG. 3;
[0061] FIG. 6 is an explanation view showing moving directions of
the nozzle shown in FIG. 3;
[0062] FIGS. 7A and 7B are explanation views of another embodiment
of the cleaning device;
[0063] FIGS. 8A and 8B are explanation views of another embodiment
of the cleaning device;
[0064] FIG. 9 is an explanation view of another embodiment of the
cleaning device;
[0065] FIG. 10 is an explanation view of a lapping machine, which
is an example of the abrasive machines;
[0066] FIG. 11 is a partial plan view of an abrasive face of a
lower abrasive plate of the lapping machine shown in FIG. 10;
[0067] FIG. 12 is an explanation view of a conventional cleaning
device;
[0068] FIG. 13 is an explanation view of a nozzle section of the
conventional cleaning device shown in FIG. 12; and
[0069] FIG. 14 is an explanation view showing a state, in which the
nozzle section shown in FIG. 13 is located in the vicinity of outer
edges of abrasive plates.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0070] Preferred embodiments of the present invention will now be
described in detail with reference to the accompanying
drawings.
[0071] An embodiment of the cleaning device of the present
invention is shown in FIG. 1. In the cleaning device shown in FIG.
1, two nozzles 100a and 100b, each of which is enclosed by a brush
102 for preventing jetted water from scattering in air, are
respectively provided to an upper end and a lower end of a shaft
106, which is extended along abrasive faces of an upper abrasive
plate 20 and a lower abrasive plate 30, and the water, which is
pressurized and supplied by a high pressure pump 104, is upwardly
and downwardly jetted from the nozzles 100a and 100b as well as the
conventional cleaning device shown in FIG. 12.
[0072] Front ends of the brushes 102, which respectively enclose
the nozzles 100a and 100b, contact and wash the abrasive faces of
the abrasive plates 20 and 30. Each of the brushes 102 forms a
space, which defines a range of scattering water jetted from the
nozzle 100a or 100b, with the abrasive face. Since the water can
flow out from the brushes 102, no water is stored in the brushes
102.
[0073] The shaft 106, to which the nozzles 100a and 100b are
provided, can be vertically moved by elevating means, e.g., a
handle 108; the shaft 106 can be horizontally moved by moving
means, e.g., a motor 110.
[0074] The cleaning device shown in FIG. 1 is capable of cleaning
the abrasive faces of the abrasive plates 20 and 30. The cleaning
device shown in FIG. 1 inserts the brushes 102 into a space between
the abrasive faces of the rotating abrasive plates 20 and 30, which
are mutually faced. The ends of the brushes 102 simultaneously
contact the abrasive faces, and the pressurized water, whose
pressure is about 50-100 atm., is jetted toward the abrasive faces
from the nozzles 100a and 100b, which are also inserted in the
space together with the brushes 102. The nozzles 100a and 100b
jetting the water are moved along the abrasive faces so as to
remove abraded dusts, etc. deposited in discharging grooves 12 and
16 of the abrasive faces.
[0075] When the abrasive faces of the abrasive plates 20 and 30 are
cleaned, the nozzles 100a and 100b are respectively located in
spaces, each of which is formed by the brush 102 and the abrasive
face to be cleaned, so that the nozzles 100a and 100b jet the water
in the spaces without scattering the water outside.
[0076] The cleaning device shown in FIG. 1 has a shaft 11 and the
brush 18, which is provided to a front end of the shaft 11. The
brush 18 can move to and away from the upper abrasive plate 20. The
brush 28 can contact an outer circumferential face of the upper
abrasive plate 20.
[0077] The brush 18 is used as closing means as shown in FIG. 2.
When the edge portions of the abrasive plates 20 and 30 are
cleaned, the nozzles 100a and 100b are moved to the outer edges of
the abrasive plates 20 and 30. Then gaps are formed between the
outer edges of the abrasive plates 20 and 30 and inner edges of the
brushes 102.
[0078] The gap between the outer edges of the abrasive plate 20 and
the inner edge of the brush 102 for cleaning the upper abrasive
plate 20 is closed by the brush 18. With this action, the water
jetted from the nozzle 100a is not scattered outside.
[0079] On the other hand, the water jetted from the nozzle 100b can
be discharged from the gap between the outer edges of the abrasive
plate 30 and the inner edge of the brush 102 for cleaning the
abrasive plate 30.
[0080] When the abrasive face of the lower abrasive plate 30 is
cleaned by the water jetted from the nozzle 100b of the cleaning
device shown in FIG. 1, the water jetted outside from the gap
between the outer edge of the lower abrasive plate 30 and the brush
member 102 for cleaning the lower abrasive plate 30 is received and
introduced outside of the cleaning device via the discharging
section 31a (see FIG. 10) as shown in FIG. 2. The discharging
section 31a is formed and opened along the outer edge of the lower
abrasive plate 30 so as to discharge slurry, etc. outside. As shown
in FIG. 10, the internal gear 52 is provided in the discharging
section 31a, so the width of the discharging section 31a is narrow.
Therefore, the water, which has once passed through the discharging
section 31a, is not returned to the abrasive face via the
discharging section 31a.
[0081] In the cleaning device shown in FIGS. 1 and 2, the whole
abrasive faces of the both abrasive plates 20 and 30 of the
abrasive machine, by the water jetted from the nozzles 100a and
100b, without scattering the water into a space, in which the
abrading mechanism is set.
[0082] In the cleaning device shown in FIGS. 1 and 2, the whole
abrasive faces of the both abrasive plates 20 and 30 are
simultaneously cleaned, so the water which has cleaned the lower
abrasive face of the upper abrasive plate 20 falls onto and
contaminates the upper abrasive face of the lower abrasive plate
30.
[0083] If width and density of the discharging grooves 12 and 16 of
the upper abrasive plate 20 are different from those of the lower
abrasive plate 30, proper moving speed for cleaning the upper
abrasive plate 20 is different from that for cleaning the lower
abrasive plate 30. Then, if the moving speed of the both nozzles
100a and 100b are equal, one of the abrasive faces cannot be
cleaned properly.
[0084] The contamination of the lower abrasive plate 30 can be
prevented by a cleaning device shown in FIG. 3.
[0085] The cleaning device shown in FIG. 3 includes: an air
cylinder unit 24 having a piston rod 24a for vertically moving a
moving unit 26; a pump 38 for supplying the pressurized water to a
nozzle section 32; and a tank 39 for supplying water to the pump
38.
[0086] The moving unit 26 includes: a casing; a motor 28; and a
ball bearing screw 36, which is rotated in a normal direction and a
reverse direction by the motor 28. By rotating the ball bearing
screw 36 by the motor 28, a moving body 25 is moved along a rail
44, which is fixed on an upper face of the casing. A shaft 29 is
rotatably connected to the motor 45, which is mounted on the moving
body 25, and extended along the abrasive faces of the abrasive
plates 20 and 30. The nozzle section 32 is provided to a front end
of the shaft 29.
[0087] With this structure, the nozzle section 32 can be moved
along the abrasive faces of the abrasive plates 20 and 30 with the
movement of the moving body 25. Further, by actuating the motor 45
to turn the nozzle section 32, the nozzle section 32 is capable of
heading to and jetting the water toward the abrasive face of the
upper abrasive plate 20 or the abrasive face of the lower abrasive
plate 30.
[0088] To detect stroke ends of the movement of the moving body 25,
position detecting sensors 41 and 42, e.g., photo sensors, are
respectively provided to ends of the rail 44.
[0089] A nozzle 35 is included in the nozzle section 32, which is
fixed to the front end of the shaft 29. The water is introduced
from the pump 38 to the nozzle 35 via a pipe 33. The nozzle 35 is
enclosed by a brush 34. Front end of the brush 34 is capable of
contacting the abrasive face of the abrasive plate 20 or 30 to wash
the abrasive face. Further, the brush 34 defines a range of
scattering the water jetted from the nozzle 35. Since the water can
flow out from the brushes 34, no water is stored in a space
enclosed by the brush 34.
[0090] A control valve 37, e.g., an electromagnetic valve, is
provided to a mid part of the pipe 33 so as to control water supply
to the nozzle 35.
[0091] A shaft 17 is extended and retracted by an air cylinder unit
19, and the brush 18 is provided to a front end of the shaft 17. By
actuating the air cylinder unit 19, the brush 18 can be moved to
and away from the outer circumferential face of the upper abrasive
plate 20.
[0092] The motors 28 and 45 of the moving unit 28, the pump 38, the
air cylinder units 19 and 24, and the control valve 37 are
controlled by a control unit 43.
[0093] In the case of cleaning the abrasive faces of the abrasive
plates 20 and 30 of the lapping machine shown in FIG. 10, firstly
the cylinder unit 22 of the lapping machine is actuated so as to
upwardly move the upper abrasive plate 20 and widen the clearance
between the abrasive plates 20 and 30, which are not rotated.
[0094] Then, the control unit 43 drives the motors 28 and 45 and
actuates the cylinder unit 24 so as to insert the nozzle section 32
into the wide clearance between the abrasive plates 20 and 30 and
turn the nozzle section 32 to head to the lower abrasive face of
the upper abrasive plate 20. With this action, the water can be
jetted toward the lower abrasive face of the upper abrasive plate
20.
[0095] Successively, the abrasive plates 20 and 30 are rotated, and
the water is jetted toward the lower abrasive face of the rotating
upper abrasive plate 20, so that the lower abrasive face of the
upper abrasive plate 20 can be cleaned. After the lower abrasive
face of the upper abrasive plate 20 is cleaned, the nozzle section
32 is turned to head to the upper abrasive face of the lower
abrasive plate 30.
[0096] Then, the upper abrasive face of the lower abrasive plate 30
is cleaned by the water jetted from the nozzle 35.
[0097] When the abrasive face of the rotating upper abrasive plate
20 is cleaned, the control unit 43 drives the motor 28 of the
moving unit 26 and actuates the 15 cylinder unit 24 so as to make
the brush 34 of the nozzle section 32 contact the outer edge part
of the rotating upper abrasive plate 20. Then, the control unit 43
drives the pump 38 and opens the valve 37 so as to jet the water
from the nozzle 35 toward the abrasive face of the upper abrasive
plate 20. Proper temperature of the water for easily wash the
abrasive face is 10-90.degree. C., preferably about 40.degree. C.;
proper pressure of the jetted water at an outlet of the pump 38 is
10.79 MPa or more, preferably 11.76 MPa or more.
[0098] Note that, amount of jetting water can be reduced by
increasing water pressure.
[0099] While the nozzle section 32 cleans the abrasive face of the
upper abrasive plate 20, the control unit 43 drives the motor 28 so
as to move the nozzle section 32 jetting the water from the outer
edge portion of the upper abrasive plate 20 toward the center
thereof.
[0100] When the nozzle section 32 reaches the center, the control
unit 43 drives the motor 28 so as to move the nozzle section 32,
whose brush 34 is contacting the abrasive face of the upper
abrasive plate 20 and whose nozzle 35 is jetting the water thereto,
toward the outer edge of the upper abrasive plate 20.
[0101] When the nozzle section 32 approaches to the outer edge of
the upper abrasive plate 20, a gap is formed between the outer edge
of the upper abrasive plate 20 and an inner edge of the brush 34.
At that time, the control unit 43 actuates the cylinder unit 19 so
as to make the brush 18 contacts the outer circumferential face of
the upper abrasive plate 20 and close the gap (see FIG. 2).
[0102] After the contact, the nozzle section 32 is moved from the
outer edge portion of the upper abrasive plate 20 to the center
thereof. When the gap between the outer edge of the upper abrasive
plate 20 and the brush 34 is disappeared, the control unit 43
actuates the cylinder unit 10 so as to leave the brush 18 from the
outer circumferential face of the upper abrasive plate 20.
[0103] Since the nozzle section 32, whose brush 34 is contacting
the abrasive face of the upper abrasive plate 20 and whose nozzle
35 is jetting the water thereto, is reciprocatively moved along the
abrasive face of the upper abrasive plate 20, the whole abrasive
face of the upper abrasive plate 20 can be cleaned.
[0104] Proper time for cleaning the abrasive face of the abrasive
plate 20 was previously known by experiments, and it is inputted to
a timer. When the set time elapsed, cleaning of the upper abrasive
plate 20 is completed.
[0105] Note that, the control unit 43 can know if the nozzle
section 32 reaches the outer edge or the center of the upper
abrasive plate 20 by signals from the sensors 41 and 42.
[0106] When the control unit 43 receives a signal from the timer
which indicates the termination of the cleaning of the upper
abrasive plate 20, the control unit 43 stops the pump 38 and closed
the valve 37, then drives the motor 45 so as to turn and head the
nozzle section 32 to the upper abrasive face of the lower abrasive
plate 30.
[0107] When the brush 34 of the nozzle section 32 contacts an outer
edge portion of the lower abrasive plate 30, the control unit 43
drives the pump 38 and opens the valve 37, so that the water is
jetted from the nozzle 35 toward the abrasive face of the lower
abrasive plate 30 so as to clean the abrasive face of the lower
abrasive plate 30.
[0108] As well as the abrasive face of the upper abrasive plate 20,
the abrasive face of the lower abrasive plate 30 is cleaned by
controlling the motor 28 so as to reciprocatively move the nozzle
section 32, whose brush 34 is contacting the abrasive face of the
lower abrasive plate 30 and whose nozzle 35 is jetting the water
thereto, between the outer edge of the lower abrasive plate 30 and
the center thereof.
[0109] As described above, when the lower abrasive pate 30 is
cleaned, the water, which has once passed through the discharging
section 31a (see FIG. 10), is not returned to the abrasive face of
the lower abrasive plate 30. Therefore, means for closing a gap
between the outer edge of the lower abrasive plate 30 and the inner
edge of the brush 34 is not required, but the closing means may be
provided for the lower abrasive plate 30.
[0110] Preferably, the moving speed of the nozzle 35 for cleaning
the upper abrasive plate 20 and that for cleaning the lower
abrasive plate 30 are independently defined so as to properly
remove abraded dusts deposited in the grooves 12 and 16 (see FIG.
11) of the abrasive faces. The proper speed for the abrasive plates
20 and 30 were respectively known by experiments and stored in the
control unit 43.
[0111] Since the proper moving speed of the nozzle section 32
depends on the width and density of the discharging grooves 12 and
16 of each abrasive face, the moving speed for cleaning the upper
abrasive plate 20 and the lower abrasive plate 30 were previously
defined on the basis of experiments and stored in the control unit
43.
[0112] By reciprocatively moving the nozzle section 32, whose brush
34 is contacting the abrasive face of the lower abrasive plate 30
and whose nozzle 35 is jetting the water thereto, the whole
abrasive face of the lower abrasive plate 30 can be cleaned. While
moving the nozzle section 32, the abraded dusts can be removed from
the abrasive face of the lower abrasive plate 30. Further, the
water, which has washed the abrasive face of the upper abrasive
plate 20 and fallen onto the abrasive face of the lower abrasive
plate 30, also can be removed, so that the contamination of the
lower abrasive plate 30 can be securely prevented.
[0113] Proper time for cleaning the abrasive face of the lower
abrasive plate 30 was also previously known by experiments, and it
is inputted to the timer. When the set time elapsed, cleaning of
the lower abrasive plate 30 is completed.
[0114] When the control unit 43 receives a signal from the timer
which indicates the termination of the cleaning of the lower
abrasive plate 30, the control unit 43 stops the pump 38 and closed
the valve 37.
[0115] After the cleaning of the abrasive faces of the both
abrasive plates 20 and 30 are completed, the nozzle section 32 is
moved out from the clearance between the abrasive plates 20 and
30.
[0116] The moving speed of the nozzle section 32 may be fixed. And,
the moving speed may be varied on the basis of area of cleaning the
abrasive face and peripheral speed of the abrasive plates 20 and
30. For example, the cleaning area of the outer edge portion of the
abrasive face is broader than that of the center portion thereof,
and the peripheral speed of the outer edge portion is higher than
that of the center portion. Therefore, the moving speed of the
nozzle section 32 for cleaning the outer edge portion may be lower
than that for cleaning the center portion so as to make the
cleaning area in the outer edge portion broader.
[0117] The nozzle section 32 shown in FIG. 3 has one nozzle 35. To
shorten the time for cleaning the abrasive faces of the both
abrasive plates 20 and 30, a plurality of the nozzles 35 may be
provided as shown in FIGS. 4A and 4B. A plurality of the nozzles 35
may be arranged parallel in the direction of moving the nozzle
section 32 (see FIG. 4A) or serially arranged in said direction
(see FIG. 4B).
[0118] Further, all or some of the nozzles 35 may jet the water
with supersonic waves. In this case, for example, some nozzles 35
jets the high pressure water, whose pressure at the outlet of the
pump 38 is 10.79 MPa or more; other nozzles 35 jets low pressure
water, whose pressure at the outlet of the pump 38 is less than
10.79 MPa, and irradiate supersonic waves toward the low pressure
water. By using the high pressure water and the low pressure water
to which the supersonic waves are irradiated, the abraded dusts
deposited in the grooves 12 and 16 can be broken by the supersonic
waves, and they can be scraped out by the high pressure water.
[0119] Note that, some of the nozzles 35 may jet a liquid including
an anticorrosive agent.
[0120] In the cleaning device shown in FIGS. 3-4B, length of hairs
of the brush 34, which encloses the nozzle 35, are fixed, but the
length of the hairs of the brush 34 may be varied as shown in FIG.
5. The brush 34 shown in FIG. 5 has a dual structure including an
inner brush 34a and an outer brush 34b. The length of hairs of the
inner brush 34a is shorter than that of the outer brush 34b. In
FIG. 5, the short inner brush 34a contacts and cleans the abrasive
face of the upper abrasive plate 20; the long outer brush 34b
enters and cleans the grooves 12 and 16 of the abrasive face.
[0121] In the cleaning device shown in FIGS. 3-5, the nozzle
section 32 is linearly moved between the outer edge and the center
of the abrasive plate. In FIG. 6, this structure is shown as the
device "A". On the other hand, the nozzle section 32 may be turned
with respect to the abrasive plate. The turnable device "B" is also
shown in FIG. 6. Of course, the both devices "A" and "B" may be
combined.
[0122] In the cleaning device shown in FIGS. 1 and 2 too, the
abrasive face of the lower abrasive plate 30 can be cleaned after
the abrasive face of the upper abrasive plate 20 is cleaned as well
as the cleaning device shown in FIGS. 3-5. In this case, for
example, two pipes for supplying the water are connected to each of
the nozzles 100a and 100b, and a control valve, e.g., an
electromagnetic valve, is provided to each pipe. The control valves
may be controlled by a control unit. The control unit opens the
valve for supplying the water to the nozzle 100a so as to clean the
abrasive face of the upper abrasive plate 20. After the upper
abrasive plate 20 is cleaned, the control unit opens the valve for
supplying the water to the nozzle 100b so as to clean the abrasive
face of the lower abrasive plate 30.
[0123] In the cleaning device shown in FIGS. 3-6, the nozzle 35
firstly cleans the lower abrasive face of the upper abrasive plate
20, then the nozzle 35 is turned to clean the upper abrasive face
of the lower abrasive plate 30. With this structure, working
efficiency of the cleaning device shown in FIGS. 3-6 is lower than
that of the cleaning device shown in FIGS. 1 and 2, which is
capable of simultaneously jetting the water from the nozzles 100a
and 100b.
[0124] This disadvantage can be solved by a cleaning device shown
in FIG. 7A, in which a plurality of the nozzle sections 32a, 32b
and 32c are linearly arranged on a shaft 29 with regular
separations.
[0125] By linearly providing the nozzle sections 32a, 32b and 32c
on the shaft 29 with the regular separations, the nozzle section
32c, which is located on the motor 45 side, corresponds to the
outer edges of the abrasive plates 20 and 30, and the nozzle
section 32a corresponds to inner portions of the abrasive plates 20
and 30 (see FIG. 7B). Since a plurality of the nozzles 32a, 32b and
32c are linearly arranged on the shaft as shown in FIG. 7A, strokes
of the nozzle sections 32a, 32b and 32c can be shorter than the
stroke of the nozzle section 32 shown in FIG. 3, in which one
nozzle section 32 is provided on the shaft 29. Therefore, working
efficiency can be improved.
[0126] Since the shaft 29 is turned by the motor 45 together with
the nozzle sections 32a, 32b and 32c, the nozzle sections 32a, 32b
and 32c can be simultaneously headed to the same direction. Namely,
the nozzle sections 32a, 32b and 32c are firstly headed to the
lower abrasive face of the upper abrasive plate 20, and the water
is simultaneously jetted from the nozzle sections 32a, 32b and 32c
so as to clean the lower abrasive face of the upper abrasive plate
20. After the upper abrasive plate 20 is cleaned, the nozzle
sections 32a, 32b and 32c are turned and headed to the upper
abrasive face of the lower abrasive plate 30, and the water is
simultaneously jetted from the nozzle sections 32a, 32b and 32c so
as to clean the upper abrasive face of the lower abrasive plate
30.
[0127] Note that, in the cleaning device shown in FIG. 7A,
structural elements shown in FIG. 3 are assigned the same symbols
and explanation is omitted.
[0128] The working efficiency of cleaning the abrasive plates can
be improved by a cleaning device shown in FIG. 8A, too. The
cleaning device includes: a nozzle section 32d including a nozzle
35d for jetting water toward the lower abrasive face of the upper
abrasive plate 20; and a nozzle section 32e including a nozzle 35e
for jetting water toward the upper abrasive face of the lower
abrasive plate 30. The nozzle sections 32d and 32e are
independently moved.
[0129] If the nozzle sections 32d and 32e are moved together, the
water which has washed the lower abrasive face of the upper
abrasive plate 20 falls onto and contaminates the upper abrasive
face of the lower abrasive plate 30. To solve the disadvantage, the
water falls onto the lower abrasive plate 30 is removed as shown in
FIG. 8A. Namely, the movement of the nozzle section 32e is a
prescribed time behind the movement of the nozzle section 32d so as
to securely remove the water fallen onto the upper abrasive face of
the lower abrasive plate 30, so that the contamination of the lower
abrasive plate 30 can be securely prevented.
[0130] The nozzle section 32e may be provided immediately below the
nozzle section 32d (see FIG. 8A); the nozzle sections 32d and 32e
may be arranged with a proper separation (see FIG. 8B).
[0131] Note that, in FIG. 8A, heading of the nozzle sections 32e
and 32e may be fixed.
[0132] The cleaning devices shown in FIGS. 8A and 8B are separated
from the abrasive machine, but they may be assembled in the
abrasive machine.
[0133] The closing brush 18 may include a nozzle, to which the
water is supplied via the hollow shaft 11. By jetting the water
from the nozzle, the brush 18 can wash the outer circumferential
face of the upper abrasive plate 20. Of course, the brush 18 can
close the gap between the outer edge of the upper abrasive plate 20
and the inner edge of the brush 34 of the nozzle section 32, so
that scattering the jetted water from the gap can be prevented.
[0134] In the cleaning devices shown in FIGS. 1-8B, the brush 18
(the closing means) is provided to the front end of the shaft and
moved close to and away from the outer circumferential face of the
upper abrasive plate 20.
[0135] In a cleaning device shown in FIG. 9, an enclosing member 15
encloses a space including the abrasive plates 20 and 30 and
prevents the water, which is jetted from the nozzle 35, from
scattering outside. By employing the enclosing member 15, the
closing means, e.g., the brush 18, can be omitted.
[0136] In the cleaning device shown in FIG. 9, structural elements
shown in FIG. 3 are assigned the same symbols and explanation will
be omitted.
[0137] Further, the structures shown in FIGS. 4A-8B may be employed
in the cleaning device shown in FIG. 9. Note that, their
explanation will be omitted, too.
[0138] In the above described cleaning devices, the brush 34
encloses 35 as the preventing means, but the preventing means is
not limited to the brush 34. Net, cloth, etc., which are capable of
preventing the water from scattering outside, may be used as the
preventing means.
[0139] Further, the closing means, which closes the gap formed
between the outer edge of the upper abrasive plate 20 and the brush
34 or 102, is also not limited to the brush 18. Net, cloth, etc.,
which are capable of preventing the water from scattering from the
gap, may be used as the closing means.
[0140] The above described cleaning devices may be used for
cleaning polishing plates of a polishing machine which polishes
both side faces of a work piece, e.g., a silicon wafer. In this
case too, proper temperature of the water for cleaning the
polishing plates is 10-90.degree. C., preferably about 40.degree.
C.; proper pressure of the jetted water at an outlet of a pump is
10.79 MPa or more, preferably 11.76 MPa or more.
[0141] In the cleaning device of the present invention, the whole
abrasive faces of the upper abrasive plate and the lower abrasive
plate can be cleaned without scattering the water, which has been
jetted toward the abrasive face, into the space in which the
abrading mechanism is set.
[0142] Even if the abrasive machine is installed in a clean room,
no dirty water is scattered into the clean room. Therefore, degree
of cleanliness of the clean room can be maintained high. The
cleaning device is especially proper for a polishing machine which
is installed in a high clean room and polishes silicon wafers.
[0143] Further, in the cleaning device of the present invention,
the abrasive face of the lower abrasive plate is cleaned after the
abrasive face of the upper abrasive plate is cleaned. With this
action, the water washing the upper abrasive plate and falling onto
the upper abrasive face of the lower abrasive plate can be securely
removed when the lower abrasive plate is washed, so that the
contamination of the lower abrasive plate can be fully
prevented.
[0144] Since the upper abrasive plate and the lower abrasive plate
are separately cleaned, the moving speed of the nozzle can be
easily adjusted on the basis of the width and density of the
discharging grooves of each abrasive face. Therefore, the abrasive
faces can be fully cleaned.
[0145] By fully cleaning the abrasive faces of the abrasive plates,
damaging work pieces, which is occurred by abraded dusts, etc.
deposited in the abrasive faces, can be securely prevented, and
yield of abraded products can be improved.
[0146] The invention may be embodied in other specific forms
without departing from the spirit or essential characteristics
thereof. The present embodiments are therefore to be considered in
all respects as illustrative and not restrictive, the scope of the
invention being indicated by the appended claims rather than by the
foregoing description and all changes which come within the meaning
and range of equivalency of the claims are therefore intended to be
embraced therein.
* * * * *