U.S. patent application number 11/603119 was filed with the patent office on 2007-06-21 for transferring device.
This patent application is currently assigned to Samsung Electronics Co., Ltd.. Invention is credited to Jae-rack Choi, Jae-shin Choi, Geun-seok Jang, Hyo-gyu Kim, Joong-nam Kwon, Tea-jun Sang.
Application Number | 20070137279 11/603119 |
Document ID | / |
Family ID | 38171838 |
Filed Date | 2007-06-21 |
United States Patent
Application |
20070137279 |
Kind Code |
A1 |
Jang; Geun-seok ; et
al. |
June 21, 2007 |
Transferring device
Abstract
A transferring device including a transferring device main body;
a transferring arm which is coupled with the transferring device
main body to transfer a workpiece; and a supporting hand which has
a plurality of engaging parts coupled with the transferring arm and
forming a predetermined angle therebetween to support the workpiece
based on a force applied to the workpiece according to varying
rotation speeds of the transferring arm. Thus, a transferring
device can stably support a workpiece.
Inventors: |
Jang; Geun-seok; (Seoul,
KR) ; Choi; Jae-shin; (Anyang-si, KR) ; Choi;
Jae-rack; (Seoul, KR) ; Kim; Hyo-gyu;
(Suwon-si, KR) ; Kwon; Joong-nam; (Hwaseong-si,
KR) ; Sang; Tea-jun; (Suwon-si, KR) |
Correspondence
Address: |
STANZIONE & KIM, LLP
919 18TH STREET, N.W., SUITE 440
WASHINGTON
DC
20006
US
|
Assignee: |
Samsung Electronics Co.,
Ltd.
Suwon-si
KR
|
Family ID: |
38171838 |
Appl. No.: |
11/603119 |
Filed: |
November 22, 2006 |
Current U.S.
Class: |
72/405.12 |
Current CPC
Class: |
H01L 21/68707 20130101;
H01L 21/67742 20130101 |
Class at
Publication: |
72/405.12 |
International
Class: |
B21J 11/00 20060101
B21J011/00 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 20, 2005 |
KR |
2005-126046 |
Claims
1. A transferring device, comprising: a transferring device main
body; a transferring arm that couples with the transferring device
main body to transfer a workpiece; and a supporting hand which has
a plurality of engaging parts coupled with the transferring arm and
forms a predetermined angle therebetween to support the workpiece
based on a force applied to the workpiece according to varying
rotation speeds of the transferring arm.
2. The transferring device according to claim 1, wherein the
supporting hand comprises a coupling part which couples with the
transferring arm and a plurality of blades which extend from the
coupling part and are spaced apart from each other.
3. The transferring device according to claim 2, wherein the
engaging part comprises a first engaging part formed on the
coupling part, and a second engaging part formed on each of the
blades, and the angle between the engaging parts is defined by an
angle between the second engaging parts with respect to the center
of the workpiece.
4. The transferring device according to claim 3, wherein the angle
between the second engaging parts is determined on the basis of a
resultant force of a centrifugal force and a rotation inertial
force applied to the workpiece according to the varying rotation
speeds of the transferring arm.
5. The transferring device according to claim 4, wherein the
engaging parts is provided in a position where the resultant force
of the centrifugal force and the rotation inertial force becomes
the maximum.
6. The transferring device according to claim 3, wherein the
engaging parts are depressed from a planar surface of the
supporting hand by a predetermined depth.
7. The transferring device according to claim 3, wherein the
engaging parts form a larger diameter than the workpiece.
8. The transferring device according to claim 3, wherein the
supporting hand comprises a spacer which is depressed inside the
engaging parts.
9. The transferring device according to claim 8, wherein the spacer
has a smaller diameter than the workpiece.
10. The transferring device according to claim 3, wherein the
supporting hand comprises one of stainless steel and ceramic.
11. The transferring device according to claim 3, wherein the
supporting hand comprises an inclination part formed along edges of
the engaging parts.
12. The transferring device according to claim 1, wherein the
workpiece comprises a wafer.
13. A transferring device to transfer a workpiece, comprising: a
body; a transferring arm to extend away from and contract toward
the body; and a supporting hand to connect with the transferring
arm, the supporting hand comprising: a coupling part to engage with
the transferring arm, two blades extending from the coupling part
and spaced from each other by a predetermined amount, a stepped
engaging part having a circular stepped portion extending about a
circular region crossing the coupling part and an outer portion of
the two blades, the stepped engaging part stepped down from a
surface of the coupling part and having a diameter wider than the
workpiece, and a spacer part stepped down from the stepped engaging
part in a center portion thereof.
14. The transferring device according to claim 13, wherein an angle
X formed at the center of the diameter of the stepped engaging part
between a line extending to a center of the stepped engaging part
crossing one of the blades and a line extending to a center of the
stepped engaging part crossing the other one of the blades is
determined on the basis of a direction of a resultant force of a
centrifugal force and a rotation inertial force applied to the
workpiece according to a varying rotation speed of the transferring
arm.
15. The transferring device according to claim 14, wherein the
angle X is calculated as follows: calculating a centrifugal force
as F.sub.(centrifugal)=md.omega..sup.2 where "m" refers to the
weight of the workpiece 15, "d" is distance from the rotation
center of the transferring device main body 20 to the center of the
workpiece 15 (see FIG. 3), and ".omega." is an angular velocity
(radian/sec) of the transferring device main body, calculating an
angular acceleration .alpha.=.omega./t, where "t" refers to
acceleration time, calculating the rotation inertial force
according to an angular acceleration as F.sub.(rotation)=md.alpha.,
combining the calculated centrifugal force and the rotation
inertial force as F= {square root over
(F.sup.Q.sub.centrifugal+F.sup.Q.sub.rotation)}, and calculating
the angle X as X = cos - 1 ( F centrifugal F ) . ##EQU00002##
16. A supporting hand usable with a transferring device to transfer
a workpiece, comprising: a coupling part provided on a first end to
couple with a transferring arm of the transfer device; a couple of
blades which extend from the coupling part and are spaced apart
from each other; and a stepped engaging part stepped from the
surface of the coupling part and having a predetermined diameter
extending across the coupling part and the coupling blades to
support the workpiece thereon, the stepped engaging part having a
larger diameter than the workpiece.
17. The supporting hand according to claim 16, wherein an angle
between the engaging part on the first blade and the engaging part
on the second blade is determined on the basis of a direction of a
resultant force of a centrifugal force and a rotation inertial
force applied to the workpiece according to a varying rotation
speed of the transferring arm.
18. A method of determining an angle between blades of a transfer
device supporting hand to transfer a wafer, the method comprising:
calculating an optimal rotation speed of a transferring device main
body; and calculating an angle between a predetermined part of two
blades with respect to a center portion of a wafer holding area of
the supporting hand.
19. The method of according to claim 18, wherein the calculating an
optimal rotation speed of the transferring device comprises:
calculating a rotation speed in the speed increasing region where
the transferring device main body starts rotating and reaches the
optimal speed, the uniform speed region where the transferring
device rotates at a uniform speed, and a speed decreasing region
where the rotation speed of the transferring device main body
becomes 0 from the optimal speed.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of Korean Patent
Application No. 2005-0126046, filed on Dec. 20, 2005, in the Korean
Intellectual Property Office, the disclosure of which is
incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present general inventive concept relates to a
transferring device to transfer a workpiece, and more particularly,
to a transferring device which stably supports a workpiece.
[0004] 2. Description of the Related Art
[0005] Generally, a transferring device is used for various
purposes in various processes. There is a type of a transferring
device which transfers a wafer to a processing chamber in a
semiconductor manufacturing process. The transferring device is
installed between a loading/unloading chamber, which accommodates a
plurality of wafers, and a reaction chamber, which receives the
wafers to proceed with a predetermined process, and loads/unloads
the wafers for an etching process and a deposition process. Various
methods are introduced to transfer the wafers precisely and quickly
and to reduce the transferring time between the processes,
including raising the transferring speed or stably supporting the
wafers.
[0006] Korean Utility Model First Publication No. 20-173017 (Dec.
16, 1999) discloses a wafer transferring device which prevents
errors and contamination while transferring wafers. US Patent First
Publication No. 2003/85582 (May 8, 2003) discloses a transferring
robot arm which has a projection to support a wafer. The
conventional devices comprise a robot arm to support the wafer.
Such a robot arm comprises a pin or a projection protruding from a
plate surface to stably support the wafer.
[0007] However, the conventional device has a complex configuration
to support and hold the wafer and may cause damages to the wafer
when holding the wafer using an air cylinder. Also, in the case
that the wafer needs be processed in a vacuum, the air cylinder or
a pipe may be damaged and begin to leak, and thus the overall
processes of the wafer may be affected. Further, when the
conventional device rotates faster than a predetermined speed while
supporting the wafer, the wafer may be separated from the robot
arm.
SUMMARY OF THE INVENTION
[0008] The present general inventive concept provides a
transferring device which can stably support a workpiece with a
simplified method.
[0009] Additional aspects and/or utilities of the present general
inventive concept will be set forth in part in the description
which follows and, in part, will be obvious from the description,
or may be learned by practice of the present invention.
[0010] The foregoing and/or other aspects and utilities of the
present general inventive concept are achieved by providing a
transferring device, comprising a transferring device main body; a
transferring arm which is coupled with the transferring device main
body to transfer a workpiece; and a supporting hand which has a
plurality of engaging parts coupled with the transferring arm and
forming a predetermined angle therebetween to support the workpiece
based on a force applied to the workpiece according to varying
rotation speeds of the transferring arm.
[0011] The supporting hand may comprise a coupling part which is
coupled with the transferring arm and a plurality of blades which
extend from the coupling part and spaced from each other.
[0012] The engaging part may comprise a first engaging part formed
on the coupling part, and a plurality of second engaging parts
respectively formed on the blades, and the angle between the
engaging parts is defined as an angle between the second engaging
parts with respect to the center of the workpiece.
[0013] The angle between the second engaging parts can be
determined on the basis of a resultant force of a centrifugal force
and a rotation inertial force applied to the workpiece according to
the varying rotation speeds of the transferring arm.
[0014] The engaging parts can be provided in a position where the
resultant force of the centrifugal force and the rotation inertial
force becomes the maximum.
[0015] The engaging parts can be depressed from a planar surface of
the supporting hand with a predetermined depth.
[0016] The engaging parts can form a larger diameter than the
workpiece.
[0017] The supporting hand can comprise a spacer which is depressed
inside the engaging parts.
[0018] The spacer can have a smaller diameter than the
workpiece.
[0019] The supporting hand can comprise one of stainless steel and
ceramic.
[0020] The supporting hand can comprise an inclination part which
is formed along edges of the engaging parts.
[0021] The workpiece can comprise a wafer.
[0022] The foregoing and/or other aspects and utilities of the
present general inventive concept are also achieved by providing a
transferring device to transfer a workpiece, comprising: a body; a
transferring arm to extend away from and contract toward the body;
and a supporting hand to connect with the transferring arm, the
supporting hand comprising: a coupling part to engage with the
transferring arm, two blades extending from the coupling part and
spaced from each other by a predetermined amount, a stepped
engaging part having a circular stepped portion extending about a
circular region crossing the coupling part and an outer portion of
the two blades, the stepped engaging part stepped down from a
surface of the coupling part and having a diameter wider than the
workpiece, and a spacer part stepped down from the stepped engaging
part in a center portion thereof.
[0023] An angle X formed at the center of the diameter of the
stepped engaging part between a line extending to a center of the
stepped engaging part crossing one of the blades and a line
extending to a center of the stepped engaging part crossing the
other one of the blades can be determined on the basis of a
direction of a resultant force of a centrifugal force and a
rotation inertial force applied to the workpiece according to a
varying rotation speed of the transferring arm.
[0024] The foregoing and/or other aspects and utilities of the
present general inventive concept are also achieved by providing a
supporting hand usable with a transferring device to transfer a
workpiece, comprising: a coupling part provided on a first end to
couple with a transferring arm of the transfer device; a couple of
blades which extend from the coupling part and are spaced apart
from each other; and a stepped engaging part stepped from the
surface of the coupling part and having a predetermined diameter
extending across the coupling part and the coupling blades to
support the workpiece thereon, the stepped engaging part having a
larger diameter than the workpiece.
[0025] The foregoing and/or other aspects and utilities of the
present general inventive concept are also achieved by providing a
method of determining an angle between blades of a transfer device
supporting hand to transfer a wafer, the method comprising:
calculating an optimal rotation speed of a transferring device main
body; and calculating an angle between a predetermined part of two
blades with respect to a center portion of a wafer holding area of
the supporting hand.
[0026] The calculating an optimal rotation speed of the
transferring device may comprise calculating a rotation speed in
the speed increasing region where the transferring device main body
starts rotating and reaches the optimal speed, the uniform speed
region where the transferring device rotates at a uniform speed,
and a speed decreasing region where the rotation speed of the
transferring device main body becomes 0 from the optimal speed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] These and/or other aspects and advantages of the present
general inventive concept will become apparent and more readily
appreciated from the following description of the embodiments,
taken in conjunction with the accompanying drawings of which:
[0028] FIG. 1 illustrates an arrangement of a transferring device
according to the present general inventive concept;
[0029] FIG. 2 is a perspective view of the transferring device
according to the present general inventive concept;
[0030] FIG. 3 illustrates forces which are applied to a workpiece
according as the transferring device rotates, according to the
present general inventive concept;
[0031] FIG. 4A is a plan view of a supporting hand according to the
present general inventive concept;
[0032] FIG. 4B is a side view of the supporting hand according to
the present general inventive concept;
[0033] FIGS. 5A through 5D are operational views of the
transferring device according to the present general inventive
concept; and
[0034] FIG. 6 is a control flowchart of a workpiece supporting
process of the transferring device according to the present general
inventive concept.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0035] Reference will now be made in detail to the embodiments of
the present general inventive concept, examples of which are
illustrated in the accompanying drawings, wherein like reference
numerals refer to the like elements throughout. The embodiments are
described below in order to explain the present general inventive
concept by referring to the figures.
[0036] Hereinafter, a transferring device 10 according to an
exemplarity embodiment of the present general inventive concept
will be described. A workpiece 15 can comprise a wafer which is
used in a semiconductor manufacturing process by way of
example.
[0037] As illustrated in FIGS. 1 through 3, the transferring device
10 according to the present general inventive concept can comprise
a transferring device main body 20; a transferring arm 30 which is
coupled with the transferring device main body 20 to transfer the
workpiece 15; and a supporting hand 50 coupled with the
transferring arm 30. The transferring device 10 is disposed between
a loading/unloading chamber 7 which accommodates the plurality of
workpieces 15 and a processing chamber 5 which receives the
workpiece(s) 15 to proceed with a predetermined process, and
transfers the workpiece(s) 15. The transferring device 10 may
transfer the workpiece 15 under the condition of vacuum and/or a
chemical reaction, such as a deposition process or an etching
process.
[0038] The workpiece 15 can have a predetermined thickness and
diameter according to its standard. The workpiece 15 is supported
by the supporting hand 50 and transferred by the transferring
device main body 20 or by the transferring arm 30. The workpiece 15
may have a round shape, or alternatively, a rectangular shape, such
as a small panel.
[0039] As illustrated in FIG. 2, the transferring device main body
20 can comprise a driver (not illustrated) which is coupled with
the transferring arm 30 and transfers the workpiece 15 in vertical
and horizontal directions. The transferring device main body 20 may
vary in optimal/fastest transferring speed to transfer the
workpiece 15, according to manufacturers. The transferring device
main body 20 comprises rotational regions including: a region where
the rotation speed increases from a suspension state; a region
where the optimal rotation speed is uniformly maintained; and a
region where the optimal rotation speed decreases, while
rotating.
[0040] The transferring arm 30 may comprise a driver (not
illustrated) which is coupled with the transferring device main
body 20 and provides a moving force to move between a
loading/unloading position of loading and unloading the workpiece
15 by the supporting hand 50 and a retraction position that is
retracted to be adjacent to the transferring device main body
20.
[0041] As illustrated in FIGS. 2 through 4B, the supporting hand 50
comprises a stepped engaging part 51, which is coupled with the
transferring arm 30 and has a predetermined diameter to support the
workpiece 15 based on a force applied to the workpiece 15 according
to the varying rotation speed of the transferring arm 30. The
supporting hand 50 comprises a ceramic which has high resistance to
a chemical process such as a deposition process or stainless steel
which has corrosion resistance or high strength, but is not limited
thereto. Alternatively, the supporting hand 50 may comprise various
well-known materials as necessary in order to achieve the intended
purposes of the general inventive concept as described herein. The
supporting hand 50 comprises a coupling part 53 which is provided
on a first end thereof and couples with the transferring arm 30;
and a couple of blades 55 which extend from the coupling part 53
and are spaced from each other. The supporting hand 50 further
comprises a spacer 57 which is depressed from a planar surface of
the stepped engaging part 51 with a predetermined depth. The
supporting hand 50 further comprises an inclination part 59 which
is formed along edges of the engaging part 51.
[0042] As illustrated in FIGS. 4A and 4B, the engaging part 51 is
depressed from the planar surface of the supporting hand 50 and has
a larger diameter than the workpiece 15. The engaging part 51
comprises a first engaging part 51a which is formed adjacent to the
coupling part 53; and a couple of second engaging parts 51b which
are formed adjacent to the blades 55. More specifically, each
second engaging part 51b is formed adjacent to a respective one of
the blades 55. An angle (2X) between the two second engaging parts
51b is determined on the basis of a direction of a resultant force
of a centrifugal force and a rotation inertial force applied to the
workpiece 15 according to the varying rotation speed of the
transferring arm 30.
[0043] Hereinafter, a process of determining the angle (2X) between
the second engaging parts 51b will be described. First, an optimal
rotation speed of the transferring device main body 20 is
calculated. That is, the rotation speed is calculated in the speed
increasing region where the transferring device main body 20 starts
rotating and reaches the optimal speed, the uniform speed region
where the transferring device main body 20 rotates at an uniform
speed, and a speed decreasing region where the rotation speed of
the transferring device main body 20 becomes 0 from the optimal
speed. The optimal rotation speed of the transferring device main
body 20 may be determined from a speed range including the maximum
speed, in consideration of the distance between the processes, the
size of the workpiece 15 and the type of the transferring device
main body 20. Then, the angle (2X) between the second engaging
parts 51b may be calculated as follows, based on the optimal speed
change.
[0044] First, a centrifugal force according to the varying rotation
speeds in the respective processes may be calculated as
follows.
F.sub.(centrifugal)=md.omega..sup.2 Formula 1
[0045] Here, "m" refers to the weight of the workpiece 15, "d" is
distance from the rotation center of the transferring device main
body 20 to the center of the workpiece 15 (see FIG. 3), and
".omega." is an angular velocity (radian/sec) of the transferring
device main body 20.
[0046] Then, an angular acceleration may be calculated as
follows.
.alpha.=.omega./t Formula 2
[0047] Here, "t" refers to acceleration time.
[0048] The rotation inertial force according to the angular
acceleration can be calculated as follows.
F.sub.(rotation)=md.alpha. Formula 3
[0049] Thus, the combined force of the centrifugal force and the
rotation inertial force in Formula 1 through 3 is as follows.
F= {square root over
(F.sup.Q.sub.centrifugal+F.sup.Q.sub.rotation)} Formula 4
[0050] Here, the engaging part 51 is provided in a position where
the resultant force of the centrifugal force and the rotation
inertial force calculated through the Formula 4 becomes the
maximum.
[0051] Here, the angle X (see, for example, FIG. 3) between the
resultant force and the centrifugal force may be calculated as
follows.
X = cos - 1 ( F centrifugal F ) Formula 5 ##EQU00001##
[0052] Then, the angle 2X is the angle between the second engaging
parts 51b. The engaging part 51 may vary in thickness (see FIGS. 4A
and 4B) according to the size of the workpiece 15 and the optimal
rotation speed.
[0053] The engaging part 51 is depressed from the plate surface of
the supporting hand 50 with the predetermined depth. The depth
thereof may vary according to the size and thickness of the
workpiece 15. Alternatively, the engaging part 51 may protrude from
the plate surface of the supporting hand 50 to a predetermined
height or may be installed at a predetermined position as a
plurality of pins protruding from the plate surface of the
supporting hand 50, to have a predetermined inner diameter.
[0054] Thus, the engaging part 51 of the supporting hand 50 can
stably support the workpiece 15 corresponding to the varying
rotation speed of the workpiece 15 since the engaging part 51 is
formed in consideration of the resultant force according to the
optimal rotation speed. Also, the transferring device 10 can reduce
the transferring time of the workpiece 15.
[0055] As illustrated in FIG. 4A, the coupling part 53 comprises at
least one coupling hole 53a which is formed on a side thereof to be
coupled with the transferring arm 30 by a coupling member, such as
a screw.
[0056] The blades 55 are shaped like a plate and separated from
each other, to thereby minimize the weight of the supporting hand
50.
[0057] the spacer 57 is depressed from the planar surface of the
engaging part 51 with a predetermined depth. The spacer 57 has a
smaller diameter than the workpiece 15, and thus the workpiece 15
supported by the engaging part 51 is and not in contact with the
planar surface of the spacer 57. Thus, the surface of the engaging
part 51 which contacts the workpiece 15 is minimized, thereby
preventing contamination or damages to the workpiece 15 due to
contact with the workpiece 15.
[0058] The inclination part 59, formed along the edges of the
engaging part 51, allows the workpiece 15 to be stably seated by
its own weight.
[0059] As described above, the workpiece 15 may comprise a wafer
according to the exemplary embodiment of the present general
inventive concept, but is not limited thereto. The transferring
device 10 according to the present general inventive concept may be
applicable to transferring various types of workpieces, such a
small display panel.
[0060] With the foregoing configuration, the rotating process of
the transferring device 10 according to the present general
inventive concept will be described with reference to FIGS. 5A and
6.
[0061] First, a method of providing the transferring device 10 that
supports the workpiece 15 will be described with reference to FIG.
6.
[0062] The transferring device main body 20 comprises a driver (not
illustrated) such as a robot to transfer the workpiece 15
vertically and horizontally at a stage of constituting the
transferring device main body 20 (operation S110).
[0063] The transferring arm 30 is coupled with the transferring
device main body 20 to support the workpiece 15 and to transfer the
workpiece 15 between the loading/unloading position and the
retraction position at the operation of coupling the transferring
arm 30 (operation S115).
[0064] The optimal rotation speed is calculated in the speed
increasing region where the transferring device main body 20 starts
rotating and reaches the optimal rotation speed, the uniform speed
region where the transferring device main body 20 rotates at the
uniform speed and the speed decreasing region where the rotation
speed of the transferring device main body 20 is reduced to "0"
from the optimal rotation speed, at the stage of determining the
optimal rotation speed (operation S120). Here, the optimal rotation
speed may be determined within the speed range including the
maximum rotation speed of the transferring device main body 20 in
consideration of the speed capability of the transferring device
main body 20, the processing time and the type of the workpiece
15.
[0065] Then, the angle 2X between the two second engaging parts 51b
is determined to support the workpiece 15 based on the forces
applied to the workpiece 15 according to the varying rotation
speeds of the transferring arm 30 (operation S125). The angle 2X is
calculated based on the resultant force of the centrifugal force
and the rotation inertial force applied to the workpiece 15
according to the varying rotation speeds of the transferring arm
30.
[0066] The engaging part 51 is depressed from the planar surface of
the supporting hand 50 considering the angle 2X calculated at the
stage of operation S125 (operation S130).
[0067] The supporting hand 50 having the engaging part 51 is
coupled with the transferring arm 30 by a screw or the like
(operation S135).
[0068] A process of supporting and rotating the workpiece 15 is
illustrate in FIGS. 5A and 5D.
[0069] As illustrated in FIG. 5A, the transferring arm 30 is moved
to the loading/unloading position to load the workpiece 15, and
supports the workpiece 15. As illustrated in FIG. 5B, while the
workpiece 15 is supported by the engaging part 51 of the supporting
hand 50, the transferring arm 30 is moved from the
loading/unloading position to the retraction position adjacent to
the transferring device main body 20. Then, as illustrated in FIG.
5C, the transferring arm 30 comprises the process of increasing the
speed; the process of rotating at the uniform speed; and the
process of being positioned at the predetermined position according
to the decrease of the rotation speed while rotating according to
the varying optimal rotation speed. The centrifugal force and the
rotation inertial force are applied to the workpiece 15 during the
processes. The engaging part 51 is provided in the position where
the resultant force of the centrifugal force and the rotation
inertial force becomes the maximum. As illustrated in FIG. 5D, the
transferring device main body 20 rotates to a predetermined
position, and the workpiece 15 is transferred to the processing
chamber (refer to FIG. 1).
[0070] As described above, the engaging part 51 is provided in a
direction where the maximum force is applied to the workpiece in
consideration of varying optimal rotation speeds of the
transferring device main body, thereby stably supporting the
workpiece and preventing damages to the workpiece. Also, the
rotation speed is maximized to reduce the processing time.
[0071] As described above, a workpiece is stably supported
corresponding to varying rotation speeds according to the present
general inventive concept, thereby preventing damages to the
workpiece and reducing the processing time according to the
transfer of the workpiece.
[0072] Although a few embodiments of the present general inventive
concept have been shown and described, it will be appreciated by
those skilled in the art that changes may be made in these
embodiments without departing from the principles and spirit of the
general inventive concept, the scope of which is defined in the
appended claims and their equivalents.
* * * * *