U.S. patent application number 12/355110 was filed with the patent office on 2009-05-21 for scribing method, a cutter wheel, a scribing apparatus using the cutter wheel, and an apparatus for producing the cutter wheel.
This patent application is currently assigned to Mitsuboshi Diamond Industrial Co., Ltd.. Invention is credited to Kazuya Maekawa, Noriyuki Ogasawara, Kiyoshi TAKAMATSU.
Application Number | 20090126551 12/355110 |
Document ID | / |
Family ID | 18933073 |
Filed Date | 2009-05-21 |
United States Patent
Application |
20090126551 |
Kind Code |
A1 |
TAKAMATSU; Kiyoshi ; et
al. |
May 21, 2009 |
SCRIBING METHOD, A CUTTER WHEEL, A SCRIBING APPARATUS USING THE
CUTTER WHEEL, AND AN APPARATUS FOR PRODUCING THE CUTTER WHEEL
Abstract
In a glass cutter wheel where a blade edge is formed on a
disk-shaped wheel, grooves having a predetermined shape are formed
at a predetermined pitch in a 1/4 or smaller or 3/4 or smaller
blade edge line portion of the entire perimeter of the blade edge.
The ratio of the groove portion to the entire perimeter, which
largely contributes to a scribing characteristic, is changed such
that a desired scribing characteristic can be obtained.
Inventors: |
TAKAMATSU; Kiyoshi; (Osaka,
JP) ; Maekawa; Kazuya; (Osaka, JP) ;
Ogasawara; Noriyuki; (Osaka, JP) |
Correspondence
Address: |
MARK D. SARALINO (GENERAL);RENNER, OTTO, BOISSELLE & SKLAR, LLP
1621 EUCLID AVENUE, NINETEENTH FLOOR
CLEVELAND
OH
44115-2191
US
|
Assignee: |
Mitsuboshi Diamond Industrial Co.,
Ltd.
|
Family ID: |
18933073 |
Appl. No.: |
12/355110 |
Filed: |
January 16, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10468754 |
Apr 7, 2004 |
|
|
|
12355110 |
|
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Current U.S.
Class: |
83/886 |
Current CPC
Class: |
C03B 33/03 20130101;
Y10T 225/12 20150401; Y10T 83/0385 20150401; Y10T 225/325 20150401;
Y10T 225/10 20150401; C03B 33/107 20130101; B28D 1/225 20130101;
C03B 33/027 20130101; Y10T 83/0237 20150401; C03B 33/07 20130101;
Y10T 225/321 20150401; Y10T 83/0341 20150401; Y10T 225/371
20150401; Y10T 83/9372 20150401 |
Class at
Publication: |
83/886 |
International
Class: |
B26D 3/08 20060101
B26D003/08 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 16, 2001 |
JP |
2001-76082 |
Claims
1. A cutter wheel, wherein: groove regions are formed over the
entire perimeter of the edge line portion; and a region wherein the
depth of the grooves becomes deeper, and a region where the depth
of the grooves becomes shallower, are continuously provided,
wherein the depth of the plurality of grooves is 2-200 .mu.m in
order that when performing scribing along a scribe line on a
brittle material substrate using the wheel a vertical crack is
formed in the brittle material substrate that varies periodically
in depth along the scribe line without extending through the
brittle material substrate, wherein the scribe line is formed on
the brittle material substrate, and the vertical crack is extended
by applying a force to widen horizontally the vertical crack, the
vertical crack being formed along the vertical direction of the
scribe line on the brittle material substrate, wherein the depth of
the vertical crack is periodically varied according to the depth of
the plurality of grooves under a constant load.
2. The cutter wheel according to claim 1, wherein the brittle
material substrate is a glass substrate.
Description
[0001] This application is a divisional of U.S. patent application
Ser. No. 10/468,754 filed on Aug. 22, 2003, which is hereby
incorporated herein by reference in its entirety.
TECHNICAL FIELD
[0002] The present invention relates to: a scribing method of
forming a scribe line for separating a brittle material; a cutter
wheel, which is a scribe cutter used for forming a scribe line in a
brittle material; a scribing apparatus incorporating such a cutter
wheel; and a cutter wheel production apparatus for producing such a
cutter wheel.
[0003] The brittle material includes glass, used for a glass
substrate or a bonded glass substrate, a semiconductor wafer,
ceramics, etc.
BACKGROUND ART
[0004] FIGS. 1(a) through 1(d) are cross-sectional views for
illustrating a first separation method of a liquid crystal mother
substrate in a step-by-step manner as an example of a conventional
procedure for cutting a bonded glass substrate, such as a liquid
crystal mother substrate, at a desired cutting position. In the
following descriptions, in a bonded glass substrate formed by a
pair of glass substrates, which is a liquid crystal mother
substrate, one of the glass substrates is referred to as an A-side
glass substrate, and the other glass substrate is referred to as a
B-side glass substrate, for convenience of explanation.
[0005] (1) First, as shown in FIG. 1(a), the bonded glass substrate
1 is placed on a first scribing apparatus such that the A-side
glass substrate is laid over the B-side glass substrate, and the
A-side glass substrate is scribed using a glass cutter wheel 2 so
as to form a scribe line Sa.
[0006] (2) Next, the bonded glass substrate 1 in which the scribe
line Sa was formed in the A-side glass substrate is turned over,
and transported to a second scribing apparatus. In this second
scribing apparatus, the B-side glass substrate of the bonded glass
substrate 1 is scribed using a glass cutter wheel 2 so as to form a
scribe line Sb which is parallel to the scribe line Sa as shown in
FIG. 1(b). It should be herein noted that, in the case of a liquid
crystal mother substrate, a plurality of liquid crystal panels are
formed from the liquid crystal mother substrate, and in each liquid
crystal panel, it is necessary to form terminals at a side edge
portion in one glass substrate. Thus, in many cases, the scribing
position of the scribe line Sa formed in the A-side glass substrate
and the scribing position of the scribe line Sb formed in the
B-side glass substrate are shifted from each other along a
horizontal direction as shown in FIG. 1(b).
[0007] (3) Next, the bonded glass substrate 1 where the scribe
lines Sa and Sb were formed in the A-side glass substrate and the
B-side glass substrate, respectively, is transported to a first
breaking apparatus without being turned over, i.e., without
exchanging the positions of the A-side glass substrate and the
B-side glass substrate. In the first breaking apparatus, as shown
in FIG. 1(c), the bonded glass substrate 1 is placed on a mat 4. A
break bar 3 is pushed against the B-side glass substrate of the
bonded glass substrate 1 along the scribe line Sa formed in the
A-side glass substrate. As a result, a crack extends upwardly from
the scribe line Sa, and accordingly, the lower A-side glass
substrate is broken along the scribe line Sa.
[0008] (4) Next, the bonded glass substrate 1 in which the A-side
glass substrate was broken is turned over such that the A-side
glass substrate is over the B-side glass substrate, and transported
to a second breaking apparatus. In the second breaking apparatus,
as shown in FIG. 1(d), the bonded glass substrate 1 is placed on a
mat 4. A break bar 3 is pushed against the A-side glass substrate
of the bonded glass substrate 1 along the scribe line Sb formed in
the B-side glass substrate. As a result, the lower B-side glass
substrate is broken along the scribe line Sb.
[0009] By performing above steps (1) through (4), the bonded glass
substrate 1 is separated into two at desired positions.
[0010] As illustrated in above steps (3) and (4), the break bar 3
is pushed against the upper glass substrate, whereby the lower
glass substrate is broken. For example, as shown in FIG. 1(c), when
the break bar 3 is pushed against the upper B-side glass substrate,
the A-side glass substrate and the B-side glass substrate are bent
downward at a position against which the break bar 3 is pushed,
whereby force is applied to the A-side glass substrate so as to
horizontally widen the crack formed along the vertical direction
(vertical crack) of the scribe line Sa formed in the A-side glass
substrate. As a result, the vertical crack extends upwardly so as
to reach the upper surface of the A-side glass substrate, whereby
the A-side glass substrate is separated. On the other hand, in the
scribe line Sb formed in the upper B-side glass substrate, force in
a horizontal direction from both ends of the B-side glass substrate
toward the crack, which is the opposite direction to that of the
force caused in the lower glass substrate, is applied so as to
compress the crack (vertical crack). Therefore, the B-side glass
substrate is not broken.
[0011] In the breaking steps performed at steps (3) and (4), when
the vertical crack of the scribe line Sa of the lower A-side glass
substrate is shallow as shown in FIG. 1(c), it is necessary to
apply a relatively large pushing force in order to break the A-side
glass substrate. However, when the pushing force applied by the
break bar 3 is too strong, the upper B-side glass substrate may be
broken simultaneously with the A-side glass substrate. In this
case, in the lower A-side glass substrate, the vertical crack
extends along a substantially vertical direction to break the lower
A-side glass substrate, i.e., no problem is caused. However, since
in the upper B-side glass substrate, the position where the force
is applied by the break bar 3 is different from the position of the
scribe line Sb formed in the B-side glass substrate, force is not
caused in a direction such that the upper B-side glass substrate is
broken. Thus, a separation face may be formed in an oblique
direction. Furthermore, cracks may be formed so as to be in contact
with each other so that defects (horizontal cracks) are caused at
that position of contact. A bonded glass substrate having such a
separation face extending along an oblique direction, or such
defects, has no commercial value as a liquid crystal panel.
[0012] The applicant of the present application has proposed a
separation method of a brittle substrate which can solve such
problems in Japanese Laid-Open Publication No. 6-48755 entitled
"Separation Method of Bonded Glass Substrate".
[0013] FIGS. 2(a) through 2(d) are cross-sectional views which
illustrate a second separation method for separating a brittle
material, which is described in the above publication, in a
step-by-step manner. Hereinafter, the method described in this
publication is described with reference to FIGS. 2(a) through 2(d).
In the following descriptions also, as referred to in FIGS. 1(a)
through 1(d), in a bonded glass substrate formed by a pair of glass
substrates, which is a liquid crystal mother substrate, one of the
glass substrates is referred to as an A-side glass substrate, and
the other glass substrate is referred to as a B-side glass
substrate, for convenience of explanation.
[0014] (1) First, as shown in FIG. 2(a), the bonded glass substrate
1 is placed on a first scribing apparatus such that the A-side
glass substrate is over the B-side glass substrate, and the A-side
glass substrate is scribed using a glass cutter wheel 2 so as to
form a scribe line Sa.
[0015] (2) Next, the bonded glass substrate 1 where the scribe line
Sa was formed in the A-side glass substrate is turned over, and
transported to a first breaking apparatus. In this first breaking
apparatus, as shown in FIG. 2(b), the bonded glass substrate 1 is
placed on a mat 4. A break bar 3 is pushed against the B-side glass
substrate of the bonded glass substrate 1 along the scribe line Sa
formed in the A-side glass substrate. As a result, in the lower
A-side glass substrate, a crack extends upwardly from the scribe
line Sa, and accordingly, the A-side glass substrate is broken
along the scribe line Sa.
[0016] (3) Next, the bonded glass substrate 1 where the A-side
glass substrate was broken is transported to a second scribing
apparatus without being turned over, i.e., without exchanging the
positions of the A-side glass substrate and the B-side glass
substrate. In this second scribing apparatus, the B-side glass
substrate of the bonded glass substrate 1 is scribed using a glass
cutter wheel 2 so as to form a scribe line Sb which is parallel to
the scribe line Sa as shown in FIG. 2(c). It should be herein noted
that, in the case of a liquid crystal mother substrate, a plurality
of liquid crystal panels are formed from the liquid crystal mother
substrate, and in each liquid crystal panel, it is necessary to
form terminals at a side edge portion in one glass substrate. Thus,
in many cases, the scribing position of the scribe line Sa formed
in the A-side glass substrate and the scribing position of the
scribe line Sb formed in the B-side glass substrate are shifted
from each other along a horizontal direction.
[0017] (4) Next, the bonded glass substrate 1 is turned over such
that the A-side glass substrate is over the B-side glass substrate,
and transported to a second breaking apparatus. In the second
breaking apparatus, as shown in FIG. 2(d), the bonded glass
substrate 1 is placed on a mat 4. A break bar 3 is pushed against a
portion of the A-side glass substrate of the bonded glass substrate
1 which corresponds to the scribe line Sb formed in the B-side
glass substrate. As a result, the lower B-side glass substrate is
broken along the scribe line Sb.
[0018] By performing above steps (1) through (4), the bonded glass
substrate 1 is separated into two at desired positions.
[0019] In this second separation method of a brittle material, as
illustrated in steps (2) and (4), at a breaking step, the lower
glass substrate to be broken has a scribe line whereas the upper
glass substrate to does not have a scribe line. Thus, the upper
glass substrate is not broken simultaneously with the breakage of
the lower glass substrate. Therefore, occurrence of the problems
which may occur in the first separation method illustrated in FIGS.
1(a) through 1(d), such as a separation face extending along an
oblique direction, formation of defects, etc., can be avoided.
[0020] FIG. 3 is a side view of the glass cutter wheel 2 used in
the first and second separation methods, which is seen along a
direction perpendicular to the rotation axis of the glass cutter
wheel 2. The glass cutter wheel 2 is formed into the shape of a
disk, where .phi. denotes the wheel diameter and w denotes the
wheel thickness, and a blade edge having a blade edge angle .alpha.
is formed along the perimeter of the wheel.
[0021] The applicant of the present application further improved
the glass cutter wheel 2 shown in FIG. 3 to obtain a glass cutter
wheel which can form a deeper vertical crack, which is disclosed in
Japanese Laid-Open Publication No. 9-188534 entitled "Glass Cutter
Wheel".
[0022] FIG. 4 is a side view of a glass cutter wheel disclosed in
this publication, which is seen along the rotation axis of the
glass cutter wheel.
[0023] This glass cutter wheel 5 has undulations at the edge line
portion of a blade edge formed at the perimeter of a wheel. That
is, U-shaped or V-shaped grooves 5b are formed at the edge line
portion 5a of the blade edge. These grooves 5b are formed by
cutting notches at depth h from the edge line portion 5a at pitch
P. By forming these grooves 5b, protrusions j having a height h are
formed at pitch P.
[0024] In FIG. 4, the grooves formed at the edge line portion are
shown in a large size for the purpose of readily recognizing the
grooves. However, the actual size of the grooves is a size of the
micron order, which is not perceptible by a human eye.
[0025] TABLE 1 below shows specific numerical values of the wheel
diameter .phi., the wheel thickness w, etc. The values are shown
for two examples, Type 1 and Type 2.
TABLE-US-00001 TABLE 1 Type 1 Type 2 Wheel diameter .phi. 2.5 mm
2.0 mm Wheel thickness w 0.65 mm 0.65 mm Blade edge angle .alpha.
125.degree. 125.degree. Number of protrusions j 125 110 Height h of
protrusions j 5 .mu.m 10 .mu.m Pitch P 63 .mu.m 63 .mu.m Blade edge
load 3.6 Kgf 1.8 Kgf Scribing speed 300 mm/sec 400 mm/sec
[0026] The glass cutter wheel having undulations at the edge line
portion has a significantly improved scribing characteristic, i.e.,
a significantly improved ability to form a vertical crack. By
performing a scribing process using this glass cutter wheel, a deep
vertical crack which almost reaches the vicinity of the lower
surface of a scribed glass plate can be obtained in the scribing
process.
[0027] The glass cutter wheel 5 having undulations at the edge line
portion has a significantly improved scribing characteristic as
compared with a conventional glass cutter wheel. However, since
precise undulations are formed along the entire perimeter of the
edge line portion of the glass cutter wheel 5, the process and
formation of the undulations in the edge line portion requires a
long process time, and there are some problems in
processibility.
[0028] In the case where the second separation method illustrated
in FIG. 2 is performed using the glass cutter wheel 5 having
undulations at the edge line portion, a scribe line Sb of a deep
vertical crack is formed in the B-side glass substrate, and in some
cases, the bonded glass substrate 1 is substantially separated at
the time when the upper B-side glass substrate has been scribed at
Step (3). Thus, when the bonded glass substrate 1 is transported
using a suction pad, or the like, to the second breaking apparatus
during a transition period between Step (3) and Step (4), one piece
of the separated bonded glass substrate 1 may be left in the second
scribing apparatus. Furthermore, during transportation of the
bonded glass substrate 1, one piece of the separated bonded glass
substrate 1 may fall from the suction pad. In such a case, a
production line apparatus for separating the bonded glass substrate
1 may not operate in a normal manner.
[0029] The present invention was conceived to solve the above
problems. An object of the present invention is to provide: a glass
cutter wheel where problems in processibility, which may occur in a
glass cutter wheel having undulations in the entire perimeter of
the edge line portion, are solved, and a desired scribing
characteristic can be obtained, i.e., a scribe line of a vertical
crack having a desired depth can be formed in a glass substrate
separation process; a scribing method for forming a scribe line
which enables separation of a brittle material; a scribing
apparatus incorporating such a cutter wheel; and a cutter wheel
production apparatus for producing such a cutter wheel.
DISCLOSURE OF THE INVENTION
[0030] A scribing method of the present invention which uses a
brittle material separation disk-shaped wheel having a central
portion in a thickness direction protruding in a circumferential
direction so as to form a blade edge at an edge line portion of the
wheel, and a plurality of grooves having a predetermined shape
formed in the edge line portion at a predetermined pitch, is
characterized in that scribing is performed using a wheel where the
ratio of a length of a region occupied by the plurality of grooves
with respect to an entire perimeter of the edge line portion is
smaller than 1, whereby a depth of a vertical crack formed inside a
scribed brittle material is periodically varied.
[0031] In the above scribing method of the present invention, it is
preferable that scribing is performed using a wheel where the ratio
of a length of a region occupied by the plurality of grooves with
respect to the entire perimeter of the edge line portion is equal
to or smaller than 3/4.
[0032] In the above scribing method of the present invention, it is
more preferable that scribing is performed using a wheel where the
ratio of a length of a region occupied by the plurality of grooves
with respect to the entire perimeter of the edge line portion is
equal to or smaller than 1/4.
[0033] A cutter wheel of the present invention which is used for
separating a brittle material, where a blade edge is formed in an
edge line portion of a disk-shaped wheel, and a plurality of
grooves having a predetermined shape are formed in the edge line
portion at a predetermined pitch, is characterized in that the
ratio of a length of a region occupied by the plurality of grooves
with respect to an entire perimeter of the edge line portion is
smaller than 1.
[0034] In the above cutter wheel of the present invention, it is
preferable that the ratio of a length of a region occupied by the
plurality of grooves with respect to the entire perimeter of the
edge line portion is greater than 1/4, and equal to or smaller than
3/4.
[0035] In the above cutter wheel of the present invention, it is
more preferable that the ratio of a length of a region occupied by
the plurality of grooves with respect to the entire perimeter of
the edge line portion is equal to or smaller than 1/4.
[0036] In the above cutter wheel of the present invention, it is
preferable that the pitch at which the plurality of grooves are
formed is 20-200 .mu.m according to a wheel diameter of 1-20
mm.
[0037] In the above cutter wheel of the present invention, it is
more preferable that the depth of the plurality of grooves is 2-200
.mu.m according to a wheel diameter of 1-20 mm.
[0038] In the above cutter wheel of the present invention, it is
more preferable that the cutter wheel is integrally formed with a
shaft which penetrates through the wheel.
[0039] In the above cutter wheel of the present invention, it is
more preferable that at least one groove region is formed in the
edge line portion; and the grooves have different depths such that
the depth of the groove is deeper in a central portion of the
groove region than in end portions of the groove region.
[0040] Another cutter wheel of the present invention is
characterized in that: groove regions are formed over the entire
perimeter of the edge line portion; and a region where the depth of
the grooves becomes deeper, and a region where the depth of the
grooves becomes shallower, are continuously provided.
[0041] A scribing apparatus of the present invention which includes
a mechanism for moving a cutter head along the X-direction and/or
the Y-direction with respect to a table on which a brittle material
is placed, is characterized in that the cutter head is provided
with the above cutter wheel of the present invention.
[0042] A method for separating a bonded glass substrate of the
present invention which includes a first scribing step, a second
scribing step, and a breaking step, is characterized in that the
above glass cutter wheel of the present invention is used in the
second scribing step.
[0043] A method for separating a bonded glass substrate of the
present invention which includes a first scribing step, a first
breaking step, a second scribing step, and a second breaking step,
is characterized in that the above glass cutter wheel of the
present invention is used in the second scribing step.
[0044] A cutter wheel production apparatus for producing the cutter
wheel of the present invention, which includes: at least one
rotatably supported disk-shaped grinding member; and a grinding
mechanism which supports at least one cutter wheel to be ground,
and which advances and retracts the cutter wheel toward/from the
grinding member, is characterized in that the grinding mechanism
has rotation means for moving a portion of the cutter wheel which
is to be ground by the grinding member.
[0045] The above cutter wheel production apparatus of the present
invention preferably further includes: advancing/retracting means
for advancing/retracting the grinding mechanism toward/from the
grinding member; and control means for controlling the
advancing/retracting means and the rotation means.
[0046] In the above cutter wheel production apparatus of the
present invention, it is preferable that the control means controls
the rotation means based on the number of divisions and the number
of regions over the entire perimeter of an edge line portion of the
cutter wheel, so as to form a groove at a desired position in the
edge line portion.
BRIEF DESCRIPTION OF THE DRAWINGS
[0047] FIG. 1 illustrates a conventional separation procedure of a
bonded glass panel.
[0048] FIG. 2 illustrates another conventional separation procedure
of a bonded glass panel.
[0049] FIG. 3 is a front view of a glass cutter wheel.
[0050] FIG. 4 is a side view of a glass cutter wheel where grooves
are formed in an edge line portion of the wheel.
[0051] FIG. 5 is a side view of a glass cutter wheel of an
embodiment of the present invention.
[0052] FIG. 6 is a side view of a glass cutter wheel of another
embodiment of the present invention.
[0053] FIG. 7 shows a vertical crack formed when scribing is
performed using a glass cutter wheel of the present invention.
[0054] FIG. 8 illustrates a separation procedure using a scribing
apparatus which incorporates a glass cutter wheel of the present
invention.
[0055] FIG. 9 illustrates another separation procedure using a
scribing apparatus which incorporates a glass cutter wheel of the
present invention.
[0056] FIG. 10 is a side view showing a glass cutter wheel of
Example 1.
[0057] FIG. 11 is a side view showing a glass cutter wheel of
Example 2.
[0058] FIG. 12 is a side view showing a glass cutter wheel of
Example 3.
[0059] FIG. 13 is a side view showing a glass cutter wheel of
Example 4.
[0060] FIG. 14 is a side view showing a glass cutter wheel of
Example 5.
[0061] FIG. 15 is a plan view showing a general structure of a
glass cutter wheel production apparatus of embodiment 2.
[0062] FIG. 16 shows an example of a touch panel incorporated in a
manipulation section of a glass cutter wheel production
apparatus.
[0063] FIG. 17 is an example of a patrol light incorporated in a
glass cutter wheel production apparatus.
[0064] FIG. 18 is a flowchart for illustrating steps of grinding
process of a glass cutter wheel.
[0065] FIG. 19 is a front view of a scribing apparatus used in
embodiment 1.
[0066] FIG. 20 is a side view of a scribing apparatus used in
embodiment 1.
BEST MODE FOR CARRYING OUT THE INVENTION
[0067] FIG. 5 is a side view showing a glass cutter wheel 6 of
embodiment 1 of the present invention.
[0068] As shown in FIG. 5, this glass cutter wheel 6 has a region A
where grooves are formed in a blade edge line portion and a region
B where grooves are not formed in the blade edge line portion.
[0069] The ratio of the edge line portion of the region A, where
grooves are formed, with respect to the entire edge line portion
(region A+region B) (hereinafter, referred to as "the ratio of the
region A to the entire perimeter") is preferably 3/4 or less in
view of the processibility for forming grooves in the edge line of
the glass cutter wheel 6. With such a ratio, a process of forming
grooves does not take a long time, and good processibility can be
obtained.
[0070] In the case where the ratio of the region A to the entire
perimeter is 3/4 or lower and higher than 1/4, a vertical crack
whose depth periodically varies can be obtained as shown in FIG. 7
described later. In the case where the ratio of the region A to the
entire perimeter is in such a range, it is necessary to impose
limited conditions in order to obtain the above periodical
crack.
[0071] Alternatively, in the case where the ratio of the region A
to the entire perimeter is 1/4 or lower, a vertical crack whose
depth periodically varies can be stably obtained under broader
conditions. Setting the ratio of the region A to the entire
perimeter to be within this range is suitable for preventing a
problem which may occur during transportation of a brittle
substrate where a scribe line has been formed, such as the dropping
of a piece of the brittle substrate which is separated during
transportation.
[0072] The grooves 6b formed in the region A of the edge line
portion are intentionally formed on a periodic basis on the micron
order. These grooves 6b should be considered to be different from
abrasive streaks of the submicron order which are inevitably formed
during a grinding process of forming a blade edge line.
[0073] FIG. 6 shows another example of a glass cutter wheel
according to embodiment 1. In FIG. 6(a), the entire blade edge is
divided into six regions such that the regions A and the regions B
are alternately formed. In FIG. 6(b), the entire blade edge is
divided into eight regions such that the regions A and the regions
B are alternately formed.
[0074] In FIG. 6(b), the regions A where grooves are formed are
formed in a plurality of regions A1 through A4, and the regions B
where grooves are not formed are formed in a plurality of regions
B1 through B4. The length of each of the regions A1 through A4 and
regions B1 through B4 is, for example, set such that the following
relationships are satisfied:
A1=A2=A3=A4; A1+A2+A3+A4=A;
B1=B2=B3=B4; B1+B2+B3+B4=B; and
A/B=1.
In this case, the lengths of the regions A1 through A4 are all
equal, and the lengths of the regions B1 through B4 are all equal.
Further, since A/B=1 is satisfied, the ratio of the region A to the
entire perimeter is 2/4.
[0075] In an alternative example, the following relationships are
satisfied:
A1=A2.noteq.A3.noteq.A4; A1+A2+A3+A4=A;
B1=B2.noteq.B3.noteq.B4: B1+B2+B3+B4=B; and
A/B=1.
In this case, as for the regions A1 through A4 and the regions B1
through B4, the length of the region A3 and the length of the
region A4 are different from the length of the region A1 and the
length of the region A2, and the length of the region B3 and the
length of the region B4 are different from the length of the region
B1 and the length of the region B2. Further, as for the entire
perimeter, since A/B=1 is satisfied, the ratio of the region A to
the entire perimeter is 2/4.
[0076] In a further alternative example, the following
relationships are satisfied:
A1=A2.noteq.A3.noteq.A4; A1+A2+A3+A4=A;
B1=B2.noteq.B3.noteq.B4; B1+B2+B3+B4=B; and
A/B=3/1.
In this case, as for the regions A1 through A4 and the regions B1
through B4, the length of the region A3 and the length of the
region A4 are different from the length of the region A1 and the
length of the region A2, and the length of the region B3 and the
length of the region B4 are different from the length of the region
B1 and the length of the region B2. Further, as for the entire
perimeter, since A/B=3/1 is satisfied, the ratio of the region A to
the entire perimeter is 3/4.
[0077] This glass cutter wheel 6 may be formed integrally with a
shaft which is inserted in the wheel 6. As a method for integrally
forming the glass cutter wheel 6, a method of integrally grinding
the wheel 6 and the shaft, a method of attaching a blade edge and a
shaft with an adhesive and/or by welding, etc., are employed.
[0078] FIG. 7 is a schematic view generally showing a vertical
crack generated in a glass substrate when a scribe line is formed
in the glass substrate using the above glass cutter wheel 6.
[0079] In a scribe line formed by scribing glass using the glass
cutter wheel 6, the depth of a vertical crack is different in a
scribe line S.sub.A, which is formed by the region A having
grooves, and in a scribe line S.sub.B, which is formed by the
region B having no groove. In such a scribe line, a variation in
the depth is found. That is, in the scribe line S.sub.A a deep
vertical crack D.sub.A is formed due to the grooves formed in the
edge line portion, whereas in the scribe line S.sub.B a shallow
vertical crack D.sub.B is formed because grooves are not formed in
the edge line portion of the scribe line S.sub.B.
[0080] Thus, since the depth of the vertical crack periodically
varies in the case of scribing performed using the glass cutter
wheel 6 of embodiment 1, the scribing ability of the glass cutter
wheel 6 is between the scribing ability of the conventional glass
cutter wheel 2 of FIG. 2 and the scribing ability of the glass
cutter wheel 5 of FIG. 4. Furthermore, by appropriately changing
the ratio of the region A, where grooves are formed, and the region
B, where grooves are not formed, with respect to the entire
perimeter of the glass cutter wheel, a desired scribing
characteristic can be obtained, i.e., a line of a desired vertical
crack for separating a glass substrate (scribe line) can be
obtained.
[0081] Hereinafter, Examples 1-5 which illustrates specific
examples of the glass cutter wheel of embodiment 1 are
described.
EXAMPLE 1
[0082] FIG. 10 shows an embodiment of a glass cutter wheel of
Example 1. TABLE 2 below shows dimensions of the glass cutter wheel
of Example 1, such as a wheel diameter or the like.
TABLE-US-00002 TABLE 2 Wheel diameter .phi. 2.0 mm Wheel thickness
w 0.65 mm Blade edge angle .alpha. 135.degree. Depth of groove 7
.mu.m
[0083] The glass cutter wheel 6 of Example 1 was designed such that
grooves having identical depths (7 .mu.m) are continuously formed
over a 1/10 portion (8 divisions/80 divisions) of the entire
perimeter length of the edge line portion.
[0084] This glass cutter wheel 6 was used to scribe an alkali-free
glass plate having a thickness of 0.7 mm with a blade edge load of
0.16 to 0.40 MPa and at a scribing speed of 400 mm/s. In the
scribing process using the glass cutter wheel 6 of Example 1, a
scribe line where the depth of a vertical crack periodically varies
was formed as shown in FIG. 7. In the case where a load of 0.18 MPa
was used, the deep vertical crack D.sub.A shown in FIG. 7 was about
400 .mu.m, and the shallow vertical crack D.sub.B shown in FIG. 7
was about 100 .mu.m.
EXAMPLE 2
[0085] FIG. 11 shows an embodiment of a glass cutter wheel 6 of
Example 2. TABLE 3 below shows dimensions of the glass cutter wheel
shown in FIG. 11, such as a wheel diameter or the like.
TABLE-US-00003 TABLE 3 Wheel diameter .phi. 2.0 mm Wheel thickness
w 0.65 mm Blade edge angle .alpha. 135.degree. Depth of groove 7
.mu.m
[0086] The glass cutter wheel 6 of Example 2 has regions A1 and A2
at two separated positions in the perimeter of the glass cutter
wheel 6, each of which is a 1/10 portion (8 divisions/80 divisions)
of the entire perimeter length of the edge line portion, where
grooves having identical depths (7 .mu.m) are continuously formed.
Regions A1 and A2, where grooves are formed, are provided at
opposite sides of the glass cutter wheel 6 with respect to the
central axis of the glass cutter wheel 6.
[0087] This glass cutter wheel 6 was used to scribe an alkali-free
glass plate having a thickness of 0.7 mm with a blade edge load of
0.16 to 0.40 MPa and at a scribing speed of 400 mm/s. In the
scribing process using the glass cutter wheel 6 of Example 2, a
scribe line where the depth of a vertical crack periodically varies
was formed as shown in FIG. 7. In the case where a load of 0.20 MPa
was used, the deep vertical crack D.sub.A shown in FIG. 7 was about
400 .mu.m, and the shallow vertical crack D.sub.B shown in FIG. 7
was about 100 .mu.m.
EXAMPLE 3
[0088] FIG. 12 shows an embodiment of a glass cutter wheel 6 of
Example 3. TABLE 4 below shows dimensions of the glass cutter wheel
6 of Example 3, such as a wheel diameter or the like.
TABLE-US-00004 TABLE 4 Wheel diameter .phi. 2.0 mm Wheel thickness
w 0.65 mm Blade edge angle .alpha. 135.degree. Depth of groove 7
.mu.m
[0089] The glass cutter wheel 6 of Example 3 has regions A1, A2,
and A3 at three separated positions in the perimeter of the glass
cutter wheel 6, each of which is a 1/10 portion (8 divisions/80
divisions) of the entire perimeter length of the edge line portion,
where grooves having identical depths (7 .mu.m) are continuously
formed. Regions A1, A2, and A3 are provided at uniform
intervals.
[0090] This glass cutter wheel 6 was used to scribe an alkali-free
glass plate having a thickness of 0.7 mm with a blade edge load of
0.16 to 0.40 MPa and at a scribing speed of 400 mm/s. In the
scribing process using the glass cutter wheel 6 of Example 3, a
scribe line where the depth of a vertical crack periodically varies
was formed as shown in FIG. 7. In the case where a load of 0.20 MPa
was used, the deep vertical crack D.sub.A shown in FIG. 7 was about
400 .mu.m, and the shallow vertical crack D.sub.B shown in FIG. 7
was about 100 .mu.m.
EXAMPLE 4
[0091] FIG. 13 shows an embodiment of a glass cutter wheel 6 of
Example 4. TABLE 5 below shows dimensions of the glass cutter wheel
6 of Example 4, such as a wheel diameter or the like.
TABLE-US-00005 TABLE 5 Wheel diameter .phi. 2.0 mm Wheel thickness
w 0.65 mm Blade edge angle .alpha. 135.degree. Depth of groove 3,
5, 7, 7, 7, 5, 3 .mu.m
[0092] The glass cutter wheel 6 of Example 4 has region A at a
position in the perimeter of the glass cutter wheel 6, which is a
1/10 portion (8 divisions/80 divisions) of the entire perimeter
length of the edge line portion. In region A, seven grooves are
formed. These grooves are designed so as to have different depths,
3, 5, 7, 7, 7, 5, 3 .mu.m, in this order.
[0093] This glass cutter wheel 6 was used to scribe an alkali-free
glass plate having a thickness of 0.7 mm with a blade edge load of
0.16 to 0.40 MPa and at a scribing speed of 400 mm/s. In the
scribing process using the glass cutter wheel 6 of Example 4, a
scribe line where the depth of a vertical crack periodically varies
was formed as shown in FIG. 7. In the case where a load of 0.22 MPa
was used, the deep vertical crack D.sub.A shown in FIG. 7 was about
400 .mu.m, and the shallow vertical crack D.sub.B shown in FIG. 7
was about 100 .mu.m.
EXAMPLE 5
[0094] FIG. 14 shows an embodiment of a glass cutter wheel 6 of
Example 5. TABLE 6 below shows dimensions of the glass cutter wheel
6 of Example 5, such as a wheel diameter or the like.
TABLE-US-00006 TABLE 6 Wheel diameter .phi. 2.0 mm Wheel thickness
w 0.65 mm Blade edge angle .alpha. 140.degree. Number of divisions
106 Depth of groove 3, 5, 7, 7, 7, 5, 3 .mu.m
[0095] In the glass cutter wheel 6 of Example 5, the entire
perimeter of the edge line portion is divided into 106 divisions,
such that grooves having lengths of 3, 5, 7, 7, 7, 5, and 3 .mu.m
are repeatedly formed in this order along the entire perimeter.
[0096] This glass cutter wheel 6 was used to scribe an alkali-free
glass plate having a thickness of 0.7 mm with a blade edge load of
0.16 to 0.40 MPa and at a scribing speed of 400 mm/s. In the
scribing process using the glass cutter wheel 6 of Example 5, a
scribe line where the depth of a vertical crack periodically varies
was formed as shown in FIG. 7. In the case where a load of 0.29 MPa
was used, the deep vertical crack D.sub.A shown in FIG. 7 was about
400 .mu.m, and the shallow vertical crack D.sub.B shown in FIG. 7
was about 100 .mu.m.
[0097] From the above results of Examples 1-5, it was found that a
pitch of the plurality of grooves continuously formed is preferably
20-200 .mu.m according to the wheel diameter of 1-20 mm, and that
the depth of the plurality of grooves is preferably 2-200 .mu.m
according to the wheel diameter of 1-20 mm.
[0098] In the drawings used for illustrating the above-described
cutter wheels of the present invention, the grooves formed at the
edge line of the cutter wheel are shown in a large size for the
purpose of readily recognizing the grooves. However, the actual
size of the grooves is a size of the micron order, which is not
perceptible by a human eye.
[0099] Next, a method for separating the bonded glass substrate 1
using a separation apparatus which has the glass cutter wheel 6 of
embodiment 1 is described. The scribing apparatus used in the
following description is a scribing apparatus which has a mechanism
for achieving a .theta. rotation of a table, on which a glass plate
is mounted, and for moving the table along the X-direction and/or
Y-direction with respect to a cutter head.
[0100] FIGS. 19 and 20 show an example of a scribing apparatus,
where a table performs a .theta. rotation and moves along the
Y-direction, and a cutter head moves along the X-direction. FIG. 19
is a front view of the scribing apparatus, and FIG. 20 is a side
view of the scribing apparatus.
[0101] As shown in FIGS. 19 and 20, this scribing apparatus has a
table 41 on which a glass plate is mounted. The table 41 is
supported by a rotation table 42 so as to be rotatable along a
horizontal direction, and can be moved along the Y-direction
(leftward/rightward directions in FIG. 19) by rotation of a ball
screw 44. Furthermore, a cutter head 46, to which the
above-described glass cutter wheel 11 of the present invention is
rotatably attached such that the glass cutter wheel 11 is rotatable
around its shaft, is movably supported along a rail 47 so as to be
movable along the X-direction (leftward/rightward directions in
FIG. 20).
[0102] In the case where scribing is performed using this scribing
apparatus, the cutter head 46 is moved along the X-direction every
time the table 41 is moved along the Y-direction at a predetermined
pitch, whereby a glass plate mounted on the table 41 is scribed
along the X-direction. Thereafter, the table 41 is rotated by the
rotation table 42 by 90.degree., and scribing is performed in the
same manner as described above, whereby a scribe line which crosses
at right angles with the previously formed scribe line can be
formed on the glass plate.
[0103] In the above scribing apparatus, reference numeral 43
denotes a table feed motor for moving the table 41 along the
Y-direction; reference numeral 45 denotes a rail for supporting the
rotation table 42 such that the rotation table 42 is movable along
the Y-direction; reference numeral 48 denotes a cutter shaft motor
for rotating the rotatably-supported glass cutter wheel 11;
reference numerals 49 and 50 denote CCD cameras for monitoring a
glass substrate which is scribed on the table 41; and reference
numeral 51 denotes a camera supporting metal member for supporting
the CCD cameras 49 and 50.
[0104] FIGS. 8(a) through 8(c) are cross-sectional views which
illustrate a method for separating a bonded glass substrate 1 using
a separation apparatus which incorporates the glass cutter wheel 6
of embodiment 1, in a step-by-step manner. In the following
descriptions, in a bonded glass substrate formed by a pair of glass
substrates, which is a liquid crystal mother substrate, one of the
glass substrates is referred to as an A-side glass substrate, and
the other glass substrate is referred to as a B-side glass
substrate, for convenience of explanation.
[0105] (1) First, as shown in FIG. 8(a), the bonded glass substrate
1 is placed on a first scribing apparatus such that the A-side
glass substrate is laid over the B-side glass substrate, and the
A-side glass substrate is scribed using the glass cutter wheel 5 so
as to form a scribe line Sa. The first scribing apparatus uses the
glass cutter wheel 5 shown in FIG. 4, which has grooves along its
entire perimeter. In the scribe line Sa formed using this glass
cutter wheel 5, a deep vertical crack which reaches the vicinity of
the lower surface of the A-side glass substrate, indicated by Va in
the drawings, is formed.
[0106] (2) Next, the bonded glass substrate 1 where the scribe line
Sa was formed in the A-side glass substrate is turned over, and
transported to a second scribing apparatus. In this second scribing
apparatus, the B-side glass substrate of the bonded glass substrate
1 is scribed using the glass cutter wheel 6 so as to form a scribe
line Sb which is parallel to the scribe line Sa as shown in FIG.
8(b). The second scribing apparatus uses the glass cutter wheel 6
described in any of Examples 1-5. In the scribe line Sb formed
using this glass cutter wheel 6, a vertical crack Vb which
alternately includes shallow portions and deep portions on a
periodic basis is formed. It should be herein noted that, in the
case of a liquid crystal mother substrate, a plurality of liquid
crystal panels are formed from the liquid crystal mother substrate,
and in each liquid crystal panel, it is necessary to form terminals
at a side edge portion in one glass substrate. Thus, in many cases,
the scribing position of the scribe line Sa formed in the A-side
glass substrate and the scribing position of the scribe line Sb
formed in the B-side glass substrate are shifted from each other
along a horizontal direction.
[0107] (3) Next, the bonded glass substrate 1 where the scribe
lines Sa and Sb were formed in the A-side glass substrate and the
B-side glass substrate, respectively, is turned over such that the
A-side glass substrate is over the B-side glass substrate, and
transported to a breaking apparatus. In this breaking apparatus, as
shown in FIG. 8(c), the bonded glass substrate 1 is placed on a mat
4. A break bar 3 is pushed against the A-side glass substrate of
the bonded glass substrate 1 along the scribe line Sb formed in the
B-side glass substrate. As a result, in the lower B-side glass
substrate, a crack extends upwardly from the scribe line Sb, and
accordingly, the B-side glass substrate is broken along the scribe
line Sb.
[0108] By sequentially performing above steps (1) through (3), the
bonded glass substrate 1 is separated.
[0109] As previously described, in a scribing process using the
glass cutter wheel 6 of the present invention, the vertical crack
Vb which alternately includes shallow portions and deep portions on
a periodic basis is formed, so that the vertical crack Vb does not
thoroughly penetrate through the glass substrate in the thickness
direction thereof. Thus, even when the A-side glass substrate is
completely separated during when the bonded glass substrate 1 is
transported from the second scribing apparatus to the breaking
apparatus at Step (2), there is no probability that the bonded
glass substrate 1 is separated because the A-side glass substrate
is kept bonded to the B-side glass substrate.
[0110] FIGS. 9(a) through 9(d) are cross-sectional views for
illustrating a second method for separating a bonded glass
substrate 1 using a separation apparatus which incorporates the
glass cutter wheel 6 of embodiment 1, in a step-by-step manner. In
the following descriptions, in a bonded glass substrate formed by a
pair of glass substrates, which is a liquid crystal mother
substrate, one of the glass substrates is referred to as an A-side
glass substrate, and the other glass substrate is referred to as a
B-side glass substrate, for convenience of explanation.
[0111] (1) First, as shown in FIG. 9(a), the bonded glass substrate
1 is placed on a first scribing apparatus such that the A-side
glass substrate is laid over the B-side glass substrate, and the
A-side glass substrate is scribed using the glass cutter wheel 2 so
as to form a scribe line Sa. The vertical crack Va formed using
this glass cutter wheel does not result in a deep vertical crack
which reaches the vicinity of the lower surface of the glass
substrate.
[0112] (2) Next, the bonded glass substrate 1 where the scribe line
Sa was formed in the A-side glass substrate is turned over, and
transported to a first breaking apparatus. In this first breaking
apparatus, as shown in FIG. 9(b), the bonded glass substrate 1 is
placed on a mat 4. A break bar 3 is pushed against the B-side glass
substrate of the bonded glass substrate 1 along the scribe line Sa
formed in the A-side glass substrate. As a result, in the lower
A-side glass substrate, a crack extends upwardly from the scribe
line Sa, and accordingly, the A-side glass substrate is broken
along the scribe line Sa.
[0113] (3) Next, the bonded glass substrate 1 where the A-side
glass substrate was separated is transported to a second scribing
apparatus without being turned over, i.e., without exchanging the
positions of the A-side glass substrate and the B-side glass
substrate. In this second scribing apparatus, the B-side glass
substrate of the bonded glass substrate 1 is scribed using a glass
cutter wheel 6 so as to form a scribe line Sb which is parallel to
the scribe line Sa as shown in FIG. 9(c). It should be herein noted
that, in the case of a liquid crystal mother substrate, a plurality
of liquid crystal panels are formed from the liquid crystal mother
substrate, and in each liquid crystal panel, it is necessary to
form terminals at a side edge portion in one glass substrate. Thus,
in many cases, the scribing position of the scribe line Sb formed
in the B-side glass substrate and the scribing position of the
scribe line Sa formed in the A-side glass substrate are shifted
from each other along a horizontal direction.
[0114] (4) Next, the resultant bonded glass substrate 1 is turned
over such that the A-side glass substrate is over the B-side glass
substrate, and transported to a second breaking apparatus. In this
second breaking apparatus, as shown in FIG. 9(d), the bonded glass
substrate is placed on a mat 4. The break bar 3 is pushed against
the A-side glass substrate of the bonded glass substrate 1 along
the scribe line Sb formed in the B-side glass substrate. As a
result, in the lower B-side glass substrate, a crack extends
upwardly from the scribe line Sb, and accordingly, the B-side glass
substrate is broken along the scribe line Sb. A vertical crack
formed at the time of formation of the scribe line Sbin the B-side
glass substrate at Step (3) is indicated by Vb in FIG. 9(d).
[0115] As described above, in a scribing process using the glass
cutter wheel 6 of the present invention, the vertical crack Vb
which alternately includes shallow portions and deep portions on a
periodic basis is formed, so that the vertical crack Vb does not
thoroughly penetrate through the glass substrate along the
thickness direction thereof. Thus, even when the A-side glass
substrate is completely separated during when the bonded glass
substrate 1 is transported from the second scribing apparatus to
the second breaking apparatus at Step (4), there is no probability
that the bonded glass substrate 1 is separated because the B-side
glass substrate is not thoroughly separated.
[0116] In the above, the scribing methods for a bonded glass
substrate have been described. As a special case, a different
brittle material may be scribed using the scribing method of the
present invention. In this case also, a vertical crack which
alternately includes shallow portions and deep portions on a
periodic basis can be formed in the different brittle material. By
forming such a vertical crack having the depth which periodically
varies, the brittle material can be transported to a next step
without causing a thorough separation during transportation.
[0117] Next, a glass cutter wheel production apparatus for
producing a glass cutter wheel where undulations are formed at a
blade edge portion as shown in FIG. 5 is described.
[0118] FIG. 15 is a plan view showing a general structure of a
glass cutter wheel production apparatus of embodiment 2 of the
present invention.
[0119] This glass cutter wheel production apparatus 10 has a
structure for grinding an edge line portion of a blade edge of a
glass cutter wheel so as to form grooves in the blade edge.
[0120] The glass cutter wheel production apparatus 10 has a housing
13 in which a grindstone 12 rotatably supported by, and fixed to, a
spindle motor 11 is placed. In a front face of the housing 13, a
door portion 14 is provided which can be opened for introducing or
removing a glass cutter wheel to be ground. The door portion 14 is
used for a safety door, in which a safety control device (not
shown) is provided for interrupting a grinding step when the door
is opened during grinding of a glass cutter wheel.
[0121] Inside the housing 13, a grinding mechanism 15 is provided
so as to advance toward and retract from the grindstone 12.
Advancement/retraction of the grinding mechanism 15 toward/from the
grindstone 12 are achieved by a feeding motor 18. The feeding motor
18 can adjust movement of the grinding mechanism 15 to and from a
certain position by rotating a ball screw (not shown).
[0122] The grinding mechanism 15 has a wheel supporting portion 19
for supporting a glass cutter wheel during grinding. At a rear
portion of the wheel supporting portion 19, a blade edge rotation
motor 20 is provided for rotating the glass cutter wheel by a
preset angle. Furthermore, the grinding mechanism 15 has a handle
21 for alignment in the horizontal direction and a handle 22 for
alignment in the vertical direction. With these handles, alignment
in the horizontal and vertical directions is adjusted manually, or
automatically using a control mechanism (not shown).
[0123] Outside the housing 13, a control device 25 for controlling
the position and operation of the grinding mechanism 15 is
provided. Furthermore, the control device 25 has a manipulation
section 26 for designating grinding conditions for grinding of a
glass cutter wheel by the grinding mechanism 15.
[0124] In the manipulation section 26, for example, a touch panel
30 shown in FIG. 16 is provided. In the touch panel 30 which is
shown as an example in FIG. 16, a touch panel manipulation portion
31 is provided, on which various operation modes, set conditions,
alarming, etc., for the entire apparatus are displayed. In the
lower part of the touch panel 30, a power switch 32 for
manipulating the power on and power off of an operational power
source, an illumination-type push button switch 33 for designating
start of operation preparation, a warning buzzer 34 for emitting
warning information, and an emergency stop push button switch 35
for providing an instruction to stop the operation in an emergency
are provided.
[0125] Furthermore, a signal tower 40 is provided on the housing
13. The signal tower 40 is an indication light which indicates the
status of the inside of the housing, e.g., an abnormality has
occurred, the apparatus is in automatic operation, there is no
problem in opening/closing the door, etc. FIG. 17 shows an example
of the signal tower 40. In this example, there are provided a "red"
indication light 41 which indicates that an abnormality has
occurred in the housing 13, a "green" indication light 42 which
indicates that the operation performed inside the housing 13 is
automatic, and a "yellow" indication light 43 which indicates that
there is no problem in opening/closing the door.
[0126] Next, an operation of the glass cutter wheel production
apparatus 10 having the above structure is described.
[0127] First, the manipulation section 26 is manipulated to perform
initial setting of grinding conditions for a glass cutter wheel to
be ground.
[0128] In this initial setting, for example, the following
conditions are input:
[0129] Rotation angle number ratio F.sub.1 in the first region;
depth of groove, D.sub.11, . . . , D.sub.1n
[0130] Rotation angle number ratio F.sub.2 in the second region;
depth of groove, D.sub.21, . . . , D.sub.2n
[0131] Rotation angle number ratio F.sub.m in the m-th region;
depth of groove, D.sub.m1, . . . , D.sub.mn
[0132] Number of loops: L
[0133] Number of divisions in one region: N
[0134] Depth of groove: D1, D2, . . . , Dn
[0135] Number of region: R
[0136] After the initial settings have been input, a step of
grinding a glass cutter wheel is begun. FIG. 18 is a flowchart
which illustrates the step of grinding a glass cutter wheel.
Hereinafter, the step of grinding a glass cutter wheel is described
based on this flowchart.
[0137] First, at Step 1, the number of divisions is set to 0 (n=0),
and then at Step 2, the number of regions is set to 1 (r=1).
[0138] Next, at Step 3, a glass cutter wheel to be ground is
attached to the wheel supporting portion 19.
[0139] Next, the manipulation section 26 is manipulated to start an
automatic operation of the grinding mechanism 15.
[0140] Next, a position where a tip of the grindstone 12 comes into
contact with a blade edge of the glass cutter wheel is detected. In
detection of the contact position, optical means, mechanical means,
or electrical means may be used. Detection of a contact of the
blade edge of the glass cutter wheel with the grindstone 12 is
performed every time the blade edge comes into contact with the
grindstone 12.
[0141] When a position where the tip of the grindstone 12 comes
into contact with the blade edge is detected, the grinding
mechanism 15 is moved back to a standby position by the feeding
motor 18 at Step 6.
[0142] Next, at Step 7, the blade edge rotation motor 20 is rotated
so that the glass cutter wheel supported by the wheel supporting
portion 19 by a predetermined angle.
[0143] Next, at Step 8, the number of division, n, is updated to
(n+1) by adding 1 to n.
[0144] Next, at Step 9, the grinding mechanism 15 is moved toward
the grindstone 12 such that the blade edge comes in contact with
the grindstone 12, and that the n-th groove is processed so as to
have the depth of Dmn.
[0145] At Step 9, grooves are formed such that the n-th groove in
the m-th region R has depth Dmn, which corresponds to an input
value previously set in the above-described initial setting step.
Similarly, the rotation angle number in the m-th region R is
previously set based on the rotation angle number ratio F.sub.m in
the m-th region, which is an input value set in the above-described
initial setting step, for formation of the grooves.
[0146] Next, at Step 10, the grinding mechanism 15 is moved to the
standby positions.
[0147] Next, at Step 11, the number of divisions n and the number
of divisions N are compared to examine whether or not n<N is
satisfied. If n<N is satisfied, the process proceeds to Step 12.
If n<N is not satisfied, the process proceeds to Step 13.
[0148] When it is confirmed that n<N is satisfied, and the
process proceeds to Step 12, the blade edge rotation motor 20 is
rotated by a very small angle at Step 12. Then, the process returns
to Step 6, and grinding processing is performed at a position of
the blade edge rotated by the very small angle.
[0149] When it is confirmed at Step 11 that n<N is not
satisfied, this means that when the number of divisions n has
already reached the number of divisions N, the process proceeds to
Step 13, and it is examined at Step 13 whether or not r<R is
satisfied.
[0150] When it is confirmed at Step 13 that r<R is satisfied,
the process proceeds to Step 14. At Step 14, the blade edge is
rotated by the blade edge rotation motor 20 by a set angle.
[0151] Subsequently, the process proceeds to Step 15. At Step 15,
the set number of regions, r, is updated to (r+1) by adding 1.
After update of the number of regions at Step 15, the process
returns to Step 6, and the grinding processing is again
performed.
[0152] When it is confirmed at Step 13 that r<R is not
satisfied, this means that when the number of regions r has already
reached the initially-set number of regions R, the process proceeds
to Step 16, and the grinding mechanism 15 is moved back to their
original positions.
[0153] Next, at Step 17, the glass cutter where the blade edge has
been ground is removed, and the grinding process terminates.
[0154] By using the above-described glass cutter wheel production
apparatus 10 of embodiment 2, a groove having a desired depth can
be formed at a desired position of the entire perimeter of a blade
edge with satisfactory accuracy.
[0155] In the cutter wheel production apparatus shown in FIG. 15,
one grinding mechanism 15 is provided for the grindstone 12.
However, a structure where a grindstone is positioned at about the
center of the housing, and a plurality of grinding mechanisms are
provided such that the grindstone is surrounded by the grinding
mechanisms, may be employed. With such a structure, the processing
efficiency of a cutter wheel can be significantly increased
relative to the number of the grinding mechanisms provided.
[0156] Alternatively, a plurality of grindstones may be vertically
piled up and arranged such that blade edges of a plurality of
cutter wheels face the respective grindstones. Alternatively, a
structure where a plurality of cutter wheels can be attached to one
cutter wheel supporting portion of a grinding mechanism, and the
plurality of cutter wheels can be ground simultaneously in one
grinding step, may be employed. With such a structure, the
processing efficiency of a cutter wheel can be significantly
increased.
INDUSTRIAL APPLICABILITY
[0157] As described above, according to the present invention, in a
glass cutter wheel where a blade edge is formed in a disk-shaped
wheel, grooves having a predetermined shape are formed at a
predetermined pitch in 3/4 or less of the blade edge line portion
of the entire perimeter of the blade edge. Such a glass cutter
wheel has good processibility in comparison to a glass cutter wheel
where grooves are formed over the entire perimeter of the blade
edge.
[0158] Another glass cutter wheel where grooves are formed at a
predetermined pitch in 1/4 or less portion of the entire perimeter
of the blade edge can prevent formation of a vertical crack which
reaches the vicinity of a lower surface of a substrate. By changing
the ratio of grooves with respect to the entire perimeter length, a
desired scribing characteristic can be obtained. Thus, by changing
the scribing characteristic, separation of a glass substrate at a
scribe line position and the dropping of the separated glass
substrate, which may occur during transportation of the glass
substrate, can be obviated.
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