U.S. patent application number 15/234687 was filed with the patent office on 2017-02-23 for shielding unit and plating apparatus including the same.
The applicant listed for this patent is Samsung Electronics Co., Ltd.. Invention is credited to Ju-II Choi, Atsushi Fujisaki, Byung-Lyul Park, Ji-Soon Park, Kun-Sang Park.
Application Number | 20170051424 15/234687 |
Document ID | / |
Family ID | 58157890 |
Filed Date | 2017-02-23 |
United States Patent
Application |
20170051424 |
Kind Code |
A1 |
Fujisaki; Atsushi ; et
al. |
February 23, 2017 |
Shielding Unit and Plating Apparatus Including the Same
Abstract
A shielding unit for a plating apparatus may include a shielding
plate, a controlling plate and a rotary actuator. The shielding
plate may have a plurality of holes configured to permit a passage
of an electrolyte therethrough. The controlling plate may make
contact with the shielding plate. The controlling plate may have a
plurality of controlling holes for controlling an opening ratio of
the plurality of holes of the shielding plate. The rotary actuator
may rotate the controlling plate to control the opening ratio of
the plurality of holes shielding plate.
Inventors: |
Fujisaki; Atsushi;
(Seongnam-si, KR) ; Choi; Ju-II; (Seongnam-si,
KR) ; Park; Kun-Sang; (Hwaseong-si, KR) ;
Park; Byung-Lyul; (Seoul, KR) ; Park; Ji-Soon;
(Suwon-si, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Samsung Electronics Co., Ltd. |
Suwon-si |
|
KR |
|
|
Family ID: |
58157890 |
Appl. No.: |
15/234687 |
Filed: |
August 11, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C25D 17/008 20130101;
C25D 21/12 20130101 |
International
Class: |
C25D 5/02 20060101
C25D005/02; C25D 21/12 20060101 C25D021/12 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 17, 2015 |
KR |
10-2015-0115155 |
Claims
1. A shielding unit for a plating apparatus comprising: a shielding
plate having a plurality of holes configured to permit a passage of
an electrolyte therethrough; a controlling plate configured to make
contact with the shielding plate, the controlling plate having a
plurality of controlling holes for controlling an opening ratio of
the plurality of holes of the shielding plate; and a rotary
actuator configured to rotate the controlling plate to control the
opening ratio of the plurality of holes of the shielding plate.
2. The shielding unit of claim 1, wherein each of the plurality of
holes of the shielding plate has a size substantially the same as a
size of each of the plurality of controlling holes.
3. The shielding unit of claim 1, wherein the plurality of holes of
the shielding plate are arranged spaced apart from each other by
substantially a same interval.
4. The shielding unit of claim 3, wherein the plurality of
controlling holes are arranged spaced apart from each other by an
interval substantially the same as the interval between the
plurality of holes of the shielding plate.
5. The shielding unit of claim 1, wherein the shielding plate has a
circular shape, and the controlling plate has a rectangular
shape.
6. The shielding unit of claim 1, wherein the rotary actuator
rotates the controlling plate with respect to a center point of the
controlling plate.
7. The shielding unit of claim 1, wherein the shielding plate
comprises a first shielding plate and the plurality of holes
comprises a plurality of first holes, the shielding unit further
comprising a second shielding plate configured to make contact with
the controlling plate, the second shielding plate having a
plurality of second holes configured to permit a passage of an
electrolyte therethrough.
8. The shielding unit of claim 7, wherein each of the plurality of
second holes has a size substantially the same as a size of each of
the plurality of first holes, the plurality of first holes are
arranged spaced apart from each other by substantially the same
interval, and the plurality of second holes are arranged spaced
apart from each other by an interval substantially the same as the
interval between the plurality of first holes.
9. A shielding unit for a plating apparatus comprising: a shielding
plate having a plurality of s holes configured to permit a passage
of an electrolyte therethrough; a first controlling plate
configured to make contact with a first region of the shielding
plate, the first controlling plate having a plurality of first
controlling holes for controlling an opening ratio of the plurality
of holes in the first region of the shielding plate; and a second
controlling plate configured to make contact with a second region
of the shielding plate, the second controlling plate having a
plurality of second controlling holes for controlling an opening
ratio of the plurality of s holes in the second region of the
shielding plate.
10. The shielding unit of claim 9, wherein the first region
includes at least a central region of the shielding plate, the
second region includes an edge region of the shielding plate, the
first controlling plate comprises a single plate configured to make
contact with the central region of the shielding plate, and the
second controlling plate comprises a pair of plates arranged at
opposing sides of the first controlling plate and is configured to
make contact with the edge region of the shielding plate.
11. The shielding unit of claim 10, further comprising a third
controlling plate arranged between the first controlling plate and
the second controlling plates and configured to make contact with a
third region of the shielding plate, the third controlling plate
having a plurality of third controlling holes for controlling an
opening ratio of the plurality of holes in the third region of the
shielding plate.
12. The shielding unit of claim 9, wherein the first region and the
second region are defined by a radius line of the shielding
plate.
13. The shielding unit of claim 9, wherein the plurality of holes
of the shielding plate, the first controlling holes and the second
controlling holes have a substantially same size.
14. The shielding unit of claim 13, wherein the plurality of holes
of the shielding plate, the first controlling holes and the second
controlling holes are arranged spaced apart from each other by a
substantially same interval.
15. The shielding unit of claim 9, further comprising a linear
actuator configured to move linearly and individually the first
controlling plate and the second controlling plate for controlling
an opening ratio of the plurality holes of the shielding plate.
16. A shielding unit for a plating apparatus comprising: a
shielding plate having a plurality of holes configured to permit a
passage of an electrolyte therethrough; a controlling plate
positioned adjacent the shielding plate, the controlling plate
having a plurality of controlling holes configured to control an
opening ratio of the plurality of holes of the shielding plate; and
an actuator configured to move the controlling plate to control the
opening ratio of the plurality of holes of the shielding plate.
17. The shielding unit of claim 16, wherein the shielding unit is
configured to be positioned in a plating apparatus comprising a
plating bath, an anode, a cathode, and a diffusion plate between
the anode and the cathode, the shielding unit being configured to
be positioned between the diffusion plate and the cathode.
18. The shielding unit of claim 16, wherein the actuator is
configured to move the controlling plate from a first position to a
second position that changes a degree to which the plurality of
controlling holes overlap the plurality of holes of the shielding
plate to thereby control the opening ratio of the plurality of
holes of the shielding plate.
19. The shielding unit of claim 16, wherein the shielding plate
comprises a first shielding plate and the plurality of holes
comprises a plurality of first holes, the shielding unit further
comprising a second shielding plate configured to make contact with
the controlling plate, the second shielding plate having a
plurality of second holes configured to permit a passage of an
electrolyte therethrough.
20. The shielding unit of claim 19, wherein each of the plurality
of second holes has a size substantially the same as a size of each
of the plurality of first holes, the plurality of first holes are
arranged spaced apart from each other by a substantially same
interval, and the plurality of second holes are arranged spaced
apart from each other by an interval substantially the same as the
interval between the plurality of first holes.
Description
CROSS-RELATED APPLICATION
[0001] This application claims priority under 35 USC .sctn.119 to
Korean Patent Application No. 10-2015-0115155, filed on Aug. 17,
2015, the contents of which are hereby incorporated by reference in
their entirety.
BACKGROUND
[0002] 1. Field
[0003] Example embodiments relate to a shielding unit and a plating
apparatus including the same. More particularly, example
embodiments relate to a shielding unit configured to selectively
shield an electrolyte, and a plating apparatus including the
shielding unit.
[0004] 2. Description of the Related Art
[0005] Generally, a plating apparatus may include a plating bath,
an anode and a cathode. The plating bath may be configured to
receive an electrolyte. The anode and the cathode may be arranged
in the plating bath. The cathode may be arranged facing the anode.
The cathode may be configured to hold an object. A current may be
supplied from the anode to the cathode through the electrolyte to
plate a metal layer on the object.
[0006] According to related arts, the current may flow through the
electrolyte. Thus, a distribution of the electrolyte may determine
a thickness uniformity of the plated layer. In order to uniformly
distribute the electrolyte, a shielding plate may be arranged
between the anode and the cathode. The shielding plate may have a
plurality of holes through which the electrolyte may pass.
[0007] However, the holes of the shielding plate may not uniformly
distribute the electrolyte. Further, it may be required to exchange
the shielding plate for another shielding plate when a different
object is being plated.
SUMMARY
[0008] Example embodiments provide a shielding unit for a plating
apparatus that may be capable of uniformly distribute an
electrolyte without change of a shielding plate in accordance with
kinds of objects.
[0009] Example embodiments also provide a plating apparatus
including the above-mentioned shielding unit.
[0010] According to example embodiments, there may be provided a
shielding unit for a plating apparatus. The shielding unit for the
plating apparatus may include a shielding plate, a controlling
plate and a rotary actuator. The shielding plate may have a
plurality of holes configured to permit a passage of an electrolyte
therethrough. The controlling plate may make contact with the
shielding plate. The controlling plate may have a plurality of
controlling holes for controlling an opening ratio of the plurality
of holes of the shielding plate. The rotary actuator may rotate the
controlling plate to control the opening ratio of the plurality of
holes shielding plate.
[0011] In example embodiments, each of the plurality of holes of
the shielding plate may have a size substantially the same as a
size of each of the plurality of controlling holes.
[0012] In example embodiments, the plurality of holes of the
shielding plate may be arranged spaced apart from each other by
substantially the same interval. The plurality of controlling holes
may be arranged spaced apart from each other by an interval
substantially the same as the interval between the plurality of
holes of the shielding plate.
[0013] In example embodiments, the shielding plate may have a
circular shape. The controlling plate may have a rectangular
shape.
[0014] In example embodiments, the rotary actuator may rotate the
controlling plate with respect to a center point of the controlling
plate.
[0015] In example embodiments, the shielding plate is a first
shielding plate and the plurality of holes are a plurality of first
holes, and the shielding unit may further include a second
shielding plate configured to make contact with the controlling
plate. The second shielding plate may have a plurality of second
holes configured to permit a passage of an electrolyte
therethrough.
[0016] In example embodiments, each of the plurality of second
holes may have a size substantially the same as the size of each of
the plurality of first holes. The plurality of first holes may be
arranged spaced apart from each other by substantially the same
interval. The plurality of second holes may be arranged spaced
apart from each other by an interval substantially the same as the
interval between the plurality of first holes.
[0017] According to example embodiments, there may be provided a
shielding unit for a plating apparatus. The shielding unit for the
plating apparatus may include a shielding plate, a first
controlling plate and a second controlling plate. The shielding
plate may have a plurality of holes configured to permit a passage
of an electrolyte therethrough. The first controlling plate may
make contact with a first region of the shielding plate. The first
controlling plate may have a plurality of first controlling holes
for controlling an opening ratio of the plurality of holes in the
first region of the shielding plate. The second controlling plate
may make contact with a second region of the first shielding plate.
The second controlling plate may have a plurality of second
controlling holes for controlling an opening ratio of the plurality
of holes in the second region of the shielding plate.
[0018] In example embodiments, the first region may include an at
least central region of the shielding plate. The second region may
include an edge region of the shielding plate. The first
controlling plate may include a single plate configured to make
contact with the central region of the shielding plate. The second
controlling plate may include a pair of plates arranged at opposing
sides of the first controlling plate and configured to make contact
with the edge region of the shielding plate.
[0019] In example embodiments, the shielding unit may further
include a third controlling plate arranged between the first
controlling plate and the second controlling plates. The third
controlling plate may be configured to make contact with a third
region of the shielding plate. The third controlling plate may have
a plurality of third controlling holes configured to control an
opening ratio of the plurality of holes in the third region of the
shielding plate.
[0020] In example embodiments, the first region and the second
region may be defined by a radius line of the shielding plate.
[0021] In example embodiments, the plurality of holes of the
shielding plate, the first controlling holes and the second
controlling holes may have a substantially same size.
[0022] In example embodiments, the shielding unit may further
include a linear actuator configured to move the first controlling
plate and the second controlling plate linearly and individually
for controlling the opening ratio of the plurality of holes of the
shielding plate.
[0023] In example embodiments, the shielding unit may further
include a second shielding plate configured to make contact with
the first controlling plate and the second controlling plate. The
second shielding plate may have a plurality of second holes through
which the electrolyte may pass.
[0024] According to example embodiments, there may be provided a
plating apparatus. The plating apparatus may include a plating
bath, an anode, a cathode and a shielding unit. The plating bath
may be configured to receive an electrolyte. The anode may be
arranged in the plating bath. The cathode may be arranged in the
plating bath. The cathode may be arranged facing the anode. The
cathode may be configured to hold an object. The shielding unit may
include a shielding plate, a controlling plate and a rotary
actuator. The shielding plate may be arranged between the anode and
the cathode. The shielding plate may have a plurality of shielding
holes through which the electrolyte may pass. The controlling plate
may make contact with the shielding plate. The controlling plate
may have a plurality of controlling holes for controlling an
opening ratio of the plurality of shielding holes. The rotary
actuator may rotate the controlling plate to control the opening
ratio of the plurality of shielding holes.
[0025] According to example embodiments, there may be provided a
plating apparatus. The plating apparatus may include a plating
bath, an anode, a cathode and a shielding unit. The plating bath
may be configured to receive an electrolyte. The anode may be
arranged in the plating bath. The cathode may be arranged in the
plating bath. The cathode may be arranged facing the anode. The
cathode may be configured to hold an object. The shielding unit may
include a shielding plate, a first controlling plate and a second
controlling plate. The shielding plate may be arranged between the
anode and the cathode. The shielding plate may have a plurality of
holes through which an electrolyte may pass. The first controlling
plate may make contact with a first region of the shielding plate.
The first controlling plate may have a plurality of first
controlling holes for controlling an opening ratio of the plurality
of holes in the first region of the shielding plate. The second
controlling plate may make contact with a second region of the
first shielding plate. The second controlling plate may have a
plurality of second controlling holes for controlling opening ratio
of the plurality of holes in the second region of the shielding
plate.
[0026] According to example embodiments, a shielding unit for a
plating apparatus includes a shielding plate having a plurality of
holes configured to permit a passage of an electrolyte
therethrough; a controlling plate positioned adjacent the shielding
plate, the controlling plate having a plurality of controlling
holes configured to control an opening ratio of the plurality of
holes of the shielding plate; and an actuator configured to move
the controlling plate to control the opening ratio of the plurality
of holes of the shielding plate.
[0027] In example embodiments, the shielding unit is configured to
be positioned in a plating apparatus comprising a plating bath, an
anode, a cathode, and a diffusion plate between the anode and the
cathode, the shielding unit being configured to be positioned
between the diffusion plate and the cathode.
[0028] In example embodiments, the actuator is configured to move
the controlling plate from a first position to a second position
that changes a degree to which the plurality of controlling holes
overlap the plurality of holes of the shielding plate to thereby
control the opening ratio of the plurality of holes of the
shielding plate.
[0029] In example embodiments, the shielding plate includes a first
shielding plate and the plurality of holes comprises a plurality of
first holes, the shielding unit further comprising a second
shielding plate configured to make contact with the controlling
plate, the second shielding plate having a plurality of second
holes configured to permit a passage of an electrolyte
therethrough.
[0030] In example embodiments, each of the plurality of second
holes has a size substantially the same as a size of each of the
plurality of first holes, the plurality of first holes are arranged
spaced apart from each other by a substantially same interval, and
the plurality of second holes are arranged spaced apart from each
other by an interval substantially the same as the interval between
the plurality of first holes.
[0031] According to example embodiments, the controlling holes of
the controlling plate may be selectively and partially overlapped
with the plurality of holes of the shielding plate to control the
opening ratio of the plurality of holes. Thus, the electrolyte may
be uniformly distributed to improve a thickness uniformity of a
plated layer. Particularly, the opening ratio of the plurality of
holes may be controlled by changing a position of the controlling
plate in accordance with the type of object being plated so that it
may not be required to exchange the shielding plate for another
shielding plate when the object being plated is changed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] Example embodiments will be more clearly understood from the
following detailed description taken in conjunction with the
accompanying drawings. FIGS. 1 to 14 represent non-limiting,
example embodiments as described herein.
[0033] FIG. 1 is an exploded perspective view illustrating a
shielding unit in accordance with example embodiments;
[0034] FIG. 2 is a perspective view illustrating the shielding unit
in FIG. 1;
[0035] FIG. 3 is a front view illustrating the shielding unit in
FIG. 2;
[0036] FIG. 4 is a cross-sectional view taken along a line IV-IV'
in FIG. 3;
[0037] FIG. 5 is a front view illustrating a rotated controlling
plate of the shielding unit in FIG. 2;
[0038] FIG. 6 is a cross-sectional view taken along a line VI-VI'
in FIG. 5;
[0039] FIG. 7 is an exploded perspective view illustrating a
shielding unit in accordance with example embodiments;
[0040] FIG. 8 is a front view illustrating the shielding unit in
FIG. 7;
[0041] FIG. 9 is an exploded perspective view illustrating a
shielding unit in accordance with example embodiments;
[0042] FIG. 10 is a front view illustrating the shielding unit in
FIG. 9;
[0043] FIG. 11 is an exploded perspective view illustrating a
shielding unit in accordance with example embodiments;
[0044] FIG. 12 is an exploded perspective view illustrating a
shielding unit in accordance with example embodiments;
[0045] FIG. 13 is a front view illustrating the shielding unit in
FIG. 12; and
[0046] FIG. 14 is a cross-sectional view illustrating a plating
apparatus including the shielding unit in FIG. 1.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0047] Various example embodiments will be described more fully
hereinafter with reference to the accompanying drawings, in which
some example embodiments are shown. The present invention may,
however, be embodied in many different forms and should not be
construed as limited to the example embodiments set forth herein.
Rather, these example embodiments are provided so that this
disclosure will be thorough and complete, and will fully convey the
scope of the present invention to those skilled in the art. In the
drawings, the sizes and relative sizes of layers and regions may be
exaggerated for clarity.
[0048] It will be understood that when an element or layer is
referred to as being "on," "connected to" or "coupled to" another
element or layer, it can be directly on, connected or coupled to
the other element or layer or intervening elements or layers may be
present. In contrast, when an element is referred to as being
"directly on," "directly connected to" or "directly coupled to"
another element or layer, there are no intervening elements or
layers present. Like numerals refer to like elements throughout. As
used herein, the term "and/or" includes any and all combinations of
one or more of the associated listed items.
[0049] It will be understood that, although the terms first,
second, third etc. may be used herein to describe various elements,
components, regions, layers and/or sections, these elements,
components, regions, layers and/or sections should not be limited
by these terms. These terms are only used to distinguish one
element, component, region, layer or section from another region,
layer or section. Thus, a first element, component, region, layer
or section discussed below could be termed a second element,
component, region, layer or section without departing from the
teachings of the present invention.
[0050] Spatially relative terms, such as "beneath," "below,"
"lower," "above," "upper" and the like, may be used herein for ease
of description to describe one element or feature's relationship to
another element(s) or feature(s) as illustrated in the figures. It
will be understood that the spatially relative terms are intended
to encompass different orientations of the device in use or
operation in addition to the orientation depicted in the figures.
For example, if the device in the figures is turned over, elements
described as "below" or "beneath" other elements or features would
then be oriented "above" the other elements or features. Thus, the
exemplary term "below" can encompass both an orientation of above
and below. The device may be otherwise oriented (rotated 90 degrees
or at other orientations) and the spatially relative descriptors
used herein interpreted accordingly.
[0051] The terminology used herein is for the purpose of describing
particular example embodiments only and is not intended to be
limiting of the present invention. As used herein, the singular
forms "a," "an" and "the" are intended to include the plural forms
as well, unless the context clearly indicates otherwise. It will be
further understood that the terms "comprises" and/or "comprising,"
when used in this specification, specify the presence of stated
features, integers, steps, operations, elements, and/or components,
but do not preclude the presence or addition of one or more other
features, integers, steps, operations, elements, components, and/or
groups thereof.
[0052] Example embodiments are described herein with reference to
cross-sectional illustrations that are schematic illustrations of
idealized example embodiments (and intermediate structures). As
such, variations from the shapes of the illustrations as a result,
for example, of manufacturing techniques and/or tolerances, are to
be expected. Thus, example embodiments should not be construed as
limited to the particular shapes of regions illustrated herein but
are to include deviations in shapes that result, for example, from
manufacturing. Thus, the regions illustrated in the figures are
schematic in nature and their shapes are not intended to illustrate
the actual shape of a region of a device and are not intended to
limit the scope of the present invention.
[0053] Unless otherwise defined, all terms (including technical and
scientific terms) used herein have the same meaning as commonly
understood by one of ordinary skill in the art to which this
invention belongs. It will be further understood that terms, such
as those defined in commonly used dictionaries, should be
interpreted as having a meaning that is consistent with their
meaning in the context of the relevant art and will not be
interpreted in an idealized or overly formal sense unless expressly
so defined herein.
[0054] Hereinafter, example embodiments will be explained in detail
with reference to the accompanying drawings.
Shielding Unit for a Plating Apparatus
[0055] FIG. 1 is an exploded perspective view illustrating a
shielding unit in accordance with example embodiments, FIG. 2 is a
perspective view illustrating the shielding unit in FIG. 1, FIG. 3
is a front view illustrating the shielding unit in FIG. 2, and FIG.
4 is a cross-sectional view taken along a line IV-IV' in FIG.
3.
[0056] Referring to FIGS. 1 to 4, a shielding unit 100 of this
example embodiment may include a first shielding plate 110, a
second shielding plate 120, a controlling plate 130 and a rotary
actuator 140. The first shielding plate 110 and the second
shielding plate 120 may be arranged to face each other. The
controlling plate 130 may be arranged between the first shielding
plate 110 and the second shielding plate 120.
[0057] The first shielding plate 110 may be oriented toward an
anode of a plating apparatus. The first shielding plate 110 may be
fixed to a plating bath of the plating apparatus. The first
shielding plate 110 may have a plurality of first holes 112. An
electrolyte may pass through the first holes 112. The first holes
112 may be arranged spaced apart from each other in lengthwise and
breadthwise directions by substantially the same interval.
Alternatively, the first holes 112 may be arranged spaced apart
from each other in lengthwise and breadthwise directions by a
different interval. The first shielding plate 110 may have a
circular shape. Alternatively, the first shielding plate 110 may
have any suitable shape including the circular shape.
[0058] The second shielding plate 120 may be oriented toward a
cathode of the plating apparatus. The cathode may be configured to
hold an object on which a plated layer may be formed. The second
shielding plate 120 may have a shape substantially the same as the
shape of the first shielding plate 110. Thus, the second shielding
plate 120 may have the circular shape including a plurality of
second holes 122. The second holes 122 may be arranged spaced apart
from each other in the lengthwise and breadthwise directions by an
interval substantially the same as the interval between the first
holes 112. Each of the second holes 122 may have a size
substantially the same as that of each of the first holes 112.
Further, numbers of the second holes 122 may be substantially the
same as numbers of the first holes 112. Alternatively, the second
shielding plate 122 may have any suitable shape including the
circular shape. In some embodiments, the shielding unit 100 may not
include the second shielding plate 120. That is, the shielding unit
100 may include only the first shielding plate 110, the controlling
plate 130 and the rotary actuator 140.
[0059] The controlling plate 130 may be interposed between the
first shielding plate 110 and the second shielding plate 120. The
controlling plate 130, the first shielding plate 110 and the second
shielding plate 120 may have a same axis. The controlling plate 130
may be rotatably arranged in the plating bath. The controlling
plate 130 may be rotated with respect to a center point of the
controlling plate 130.
[0060] The controlling plate 130 may have a rectangular shape;
however, any suitable shape may be used. In example embodiments,
the controlling plate 130 may have a square shape. The controlling
plate 130 may have a first surface oriented toward the first
shielding plate 110, and a second surface oriented toward the
second shielding plate 120. The second surface may be opposite to
the first surface. The first surface of the controlling plate 130
may make contact with the first shielding plate 110. The second
surface of the controlling plate 130 may make contact with the
second shielding plate 120.
[0061] The controlling plate 130 may have a plurality of
controlling holes 132. The controlling holes 132 may be arranged
spaced apart from each other in the lengthwise and breadthwise
directions by an interval substantially the same as the interval
between the first holes 112. Each of the controlling holes 132 may
have a size substantially the same as the size of each of the first
holes 112. Thus, the controlling holes 132 may be fully or
partially overlapped with the first holes 112 in accordance with
rotation angles of the controlling plate 130. When the controlling
holes 132 may be fully overlapped and align with the first holes
112, the size of each of the first holes 112 may be maintained. In
contrast, when the controlling holes 132 may be partially
overlapped with the first holes 112, the first holes 112 may be
partially blocked by the controlling plate 132 so that the size of
the first hole 112 partially overlapped with the controlling hole
132 may be decreased. The size of the first holes 112 may be
controlled by changing positions of the controlling holes 132 so
that an amount of a current through the first holes 112 may be
controlled. Therefore, a thickness of the plated layer may be
controlled depending on a position of the object to improve a
thickness uniformity of the plated layer.
[0062] The rotary actuator 140 may be configured to rotate the
controlling plate 130 to control the overlapped ratios between the
controlling holes 132 and the first holes 112, which are referred
to herein as an "opening ratio." The rotary actuator 140 may rotate
the controlling plate 130 with respect to the center point of the
controlling plate 130. When the object to be plated may be
identified, the rotary actuator 140 may rotate the controlling
plate 130 to provide the first holes 112 with opening ratios. In
order to prevent the opening ratios from being changed during a
plating process, the rotary actuator 140 may not rotate the
controlling plate 130. Thus, the controlling plate 130 may be fixed
during the plating process.
[0063] Because the rotary actuator 140 may rotate the controlling
plate 130 with respect to the center point of the controlling plate
130, an edged controlling hole 132 far from the center point of the
controlling plate 132 may have a travel length relatively longer
than a travel length of a central controlling hole 132 adjacent to
the center point of the controlling plate 132.
[0064] Therefore, when the rotary actuator 140 may rotate the
controlling plate 132 under a condition that the controlling holes
132 may be fully overlapped with the first holes 112, a central
opening ratio of the first hole 112, which may correspond to an
overlapped ratio between the central first hole 112 adjacent to the
center point of the first shielding plate 110 and the central
controlling hole 132 adjacent to the center point of the
controlling plate 130, may be higher than a peripheral opening
ratio of the first hole 112, which may correspond to an overlapped
ratio between the edged first hole 112 far from the center point of
the first shielding plate 110 and the edged controlling hole 132
far from the center point of the controlling plate 132. Thus, an
amount of the electrolyte passing through the central first hole
112 may be relatively larger than an amount of the electrolyte
passing through the edged first hole 112 so that the plated layer
on an central region of the object may have a thickness greater
than a thickness of the plated layer on an edge region of the
object. Controlling the opening ratios of the first holes 112 with
respect to the central region and the edge region of the object may
be determined by an introducing direction of the electrolyte.
Because the electrolyte may be supplied from the edge region of the
object to the central region of the object, an electrolyte may be
more concentrated on the edge region of the object rather than the
central region of the object. Thus, the thickness of the plated
layer on the edge region of the object may be thicker than the
thickness of the plated layer on the central region of the object.
In order to provide the plated layer with the uniform thickness,
the electrolyte may be uniformly distributed by controlling the
opening ratios of the first holes 112.
[0065] Referring to FIGS. 3 and 4, the first holes 112 of the first
shielding plate 110 may be fully overlapped with the controlling
holes 132 of the controlling plate 130. Thus, the opening ratios of
the first holes 112 may be about 100%. The electrolyte may be
supplied to the entire regions of the object through the first
holes 112, the controlling holes 132 and the second holes 122.
However, as mentioned above, because the electrolyte may be
supplied from the edge region of the object to the central region
of the object, the amount of the electrolyte supplied to the edge
region of the object may be larger than the amount of the
electrolyte supplied to the central region of the object so that
the thickness of the plated layer on the edge region of the object
may be thicker than the thickness of the plated layer on the
central region of the object.
[0066] FIG. 5 is a front view illustrating a rotated controlling
plate of the shielding unit in FIG. 2, and FIG. 6 is a
cross-sectional view taken along a line VI-VI' in FIG. 5.
[0067] Referring to FIGS. 5 and 6, the rotary actuator 140 may
rotate the controlling plate 130 with respect to the center point
of the controlling plate 130. As mentioned above, because the
travel length of the edged controlling hole 132 far from the center
point of the controlling plate 132 may be relatively longer than
the travel length of the central controlling hole 132 adjacent to
the center point of the controlling plate 132, the central opening
ratio of the first hole 112 may be higher than the peripheral
opening ratio of the first hole 112. Thus, an amount of the
electrolyte passing through the central first hole 112 may be
larger than an amount of the electrolyte passing through the edged
first hole 112. As a result, the plated layer on the object may
have uniform thickness.
[0068] According to this example embodiment, the opening ratios of
the first holes in the first shielding plate may be selectively
controlled by rotating the controlling plate. Therefore, the plated
layer may have the uniform thickness.
[0069] FIG. 7 is an exploded perspective view illustrating a
shielding unit in accordance with example embodiments, and FIG. 8
is a front view illustrating the shielding unit in FIG. 7.
[0070] Referring to FIGS. 7 and 8, a shielding unit 100a of this
example embodiment may include a first shielding plate 110, a
second shielding plate 120, a first controlling plate 150, a second
controlling plate 160, a first linear actuator 142 and a second
linear actuator 144.
[0071] In example embodiments, the first shielding plate 110 and
the second shielding plate 120 may have substantially the same
structures as those of the first shielding plate 110 and the second
shielding plate 120 in FIG. 1, respectively. Thus, the same
reference numerals may refer to the same elements and any further
illustrations with respect to the first shielding plate 110 and the
second shielding plate 120 may be omitted herein for brevity.
[0072] The first controlling plate 150 may be configured to make
contact with a first region of the first shielding plate 110. The
second controlling plate 160 may be configured to make contact with
a second region of the first shielding plate 110. The first region
may correspond to a central region of the first shielding plate
110. The second region may correspond to an edge region of the
first shielding plate 110.
[0073] The first controlling plate 150 may be a single plate having
a rectangular shape. The second controlling plate 160 may be a pair
of plates arranged at both sides of the first controlling plate
160. Thus, a combined structure of the first controlling plate 150
and the two second controlling plates 160 may have a shape
substantially the same as the shape of the controlling plate 130 in
FIG. 1. That is, the first controlling plate 150 and the two second
controlling plates 160 may be formed by dividing the controlling
plate 130 in FIG. 1 into three plates.
[0074] The first controlling plate 150 may be configured to make
contact with the central region, an upper edge region and a lower
edge region of the first shielding plate 110. Thus, the first
region may include at least the central region of the first
shielding plate 110. The pair of the second controlling plates 160
may be configured to make contact with a left edge region and a
right edge region of the first shielding plate 110. Thus, the
second region may partially include the edge region of the first
shielding plate 110. Alternatively, the first region and the second
region of the first shielding plate 110 may not be restricted
within the above-mentioned regions. The first region and the second
region of the first shielding plate 110 may be changed in
accordance with a type of object being plated.
[0075] The first controlling plate 150 may have a plurality of
first controlling holes 152. The second controlling plate 160 may
have a plurality of second controlling holes 162. The first
controlling holes 152 and the second controlling holes 162 may be
arranged spaced apart from each other in the lengthwise and
breadthwise directions by substantially the same interval.
Alternatively, the first controlling holes 152 and the second
controlling holes 162 may be arranged spaced apart from each other
in the lengthwise and breadthwise directions by a different
interval.
[0076] The first linear actuator 142 may be configured to linearly
move the first controlling plate 150. Thus, overlapped ratios
between the first controlling holes 152 of the first controlling
plate 150 and the central first holes 112 of the first shielding
plate 110 may be adjusted to control the central opening ratio of
the central first holes 112 in the first shielding plate 110. The
first linear actuator 142 may linearly move the first controlling
plate 150 to provide the central first holes 112 of the first
shielding plate 110 with the central opening ratio. In order to
prevent the central opening ratio from being changed during the
plating process, the first linear actuator 142 may not linearly
move the first controlling plate 150. Thus, the first controlling
plate 150 may be fixed during the plating process.
[0077] The second linear actuator 144 may be configured to linearly
move the second controlling plate 160. Thus, overlapped ratios
between the second controlling holes 162 of the second controlling
plate 160 and the edged first holes 112 of the first shielding
plate 110 may be adjusted to control the peripheral opening ratio
of the edged first holes 112 in the first shielding plate 110. The
second linear actuator 144 may linearly move the second controlling
plate 160 to provide the edged first holes 112 of the first
shielding plate 110 with the peripheral opening ratio. In order to
prevent the peripheral opening ratio from being changed during the
plating process, the second linear actuator 144 may not linearly
move the second controlling plate 160. Thus, the second controlling
plate 160 may be fixed during the plating process.
[0078] Alternatively, the first controlling plate 150 may be fixed.
That is, the first linear actuator 142 may not be connected with
the first controlling plate 150. Further, the second controlling
plate 160 may be fixed. That is, the second linear actuator 144 may
not be connected with the second controlling plate 160.
[0079] According to this example embodiment, the opening ratios of
the first holes in the first shielding plate may be regionally
controlled by linearly moving the controlling plates. Therefore,
the thickness of the plated layer may be accurately controlled in
accordance with a type of object being plated.
[0080] FIG. 9 is an exploded perspective view illustrating a
shielding unit in accordance with example embodiments, and FIG. 10
is a front view illustrating the shielding unit in FIG. 9.
[0081] Referring to FIGS. 9 and 10, a shielding unit 100b of this
example embodiment may include a first shielding plate 110, a
second shielding plate 120, a first controlling plate 170, a second
controlling plate 180, a third controlling plate 190, a first
linear actuator 146, a second linear actuator 147 and a third
linear actuator 148.
[0082] In example embodiments, the first shielding plate 110 and
the second shielding plate 120 may have substantially the same
structures as those of the first shielding plate 110 and the second
shielding plate 120 in FIG. 1, respectively. Thus, the same
reference numerals may refer to the same elements and any further
illustrations with respect to the first shielding plate 110 and the
second shielding plate 120 may be omitted herein for brevity.
[0083] The first controlling plate 170 may be configured to make
contact with a first region of the first shielding plate 110. The
second controlling plate 180 may be configured to make contact with
a second region of the first shielding plate 110. The third
controlling plate 190 may be configured to make contact with a
third region of the first shielding plate 110. The first region may
correspond to a central region of the first shielding plate 110.
The second region may correspond to an edge region of the first
shielding plate 110. The third region may correspond to a middle
region between the central region and the edge region of the first
shielding plate 110.
[0084] The first controlling plate 170 may be a single plate having
a rectangular shape. The second controlling plate 180 may be a pair
of plates arranged at both sides of the first controlling plate
160. The third controlling plate 190 may be a pair of plates
arranged between the first controlling plate 170 and the second
controlling plates 180. Thus, a combined structure of the first
controlling plate 170, the two second controlling plates 180 and
the two third controlling plates 190 may have a shape substantially
the same as the shape of the controlling plate 130 in FIG. 1. That
is, the first controlling plate 170, the two second controlling
plates 180 and the two third controlling plates 190 may be formed
by dividing the controlling plate 130 in FIG. 1 into five
plates.
[0085] The first controlling plate 170 may be configured to make
contact with the central region, an upper edge region and a lower
edge region of the first shielding plate 110. Thus, the first
region may include at least the central region of the first
shielding plate 110. The pair of the second controlling plates 180
may be configured to make contact with a left edge region and a
right edge region of the first shielding plate 110. Thus, the
second region may partially include the edge region of the first
shielding plate 110. The pair of the third controlling plates 190
may be configured to make contact with the middle region between
the central region and the right and left edge regions of the first
shielding plate 110. Alternatively, the first region, the second
region and the third region of the first shielding plate 110 may
not be restricted within the above-mentioned regions. The first
region, the second region and the third region of the first
shielding plate 110 may be changed in accordance with a type of
object being plated.
[0086] The first controlling plate 170 may have a plurality of
first controlling holes 172. The second controlling plate 180 may
have a plurality of second controlling holes 182. The third
controlling plate 190 may have a plurality of third controlling
holes 192. The first controlling holes 172, the second controlling
holes 182 and the third controlling holes 192 may be arranged
spaced apart from each other in the lengthwise and breadthwise
directions by substantially the same interval. Alternatively, the
first controlling holes 172, the second controlling holes 182 and
the third controlling holes 192 may be arranged spaced apart from
each other in the lengthwise and breadthwise directions by a
different interval.
[0087] The first linear actuator 146 may be configured to linearly
move the first controlling plate 170. Thus, overlapped ratios
between the first controlling holes 172 of the first controlling
plate 170 and the central first holes 112 of the first shielding
plate 110 may be adjusted to control the central opening ratio of
the central first holes 112 in the first shielding plate 110. The
first linear actuator 146 may linearly move the first controlling
plate 170 to provide the central first holes 112 of the first
shielding plate 110 with the central opening ratio. In order to
prevent the central opening ratio from being changed during the
plating process, the first linear actuator 146 may not linearly
move the first controlling plate 170. Thus, the first controlling
plate 170 may be fixed during the plating process.
[0088] The second linear actuator 147 may be configured to linearly
move the second controlling plate 180. Thus, overlapped ratios
between the second controlling holes 182 of the second controlling
plate 180 and the edged first holes 112 of the first shielding
plate 110 may be adjusted to control the peripheral opening ratio
of the edged first holes 112 in the first shielding plate 110. The
second linear actuator 147 may linearly move the second controlling
plate 180 to provide the edged first holes 112 of the first
shielding plate 110 with the peripheral opening ratio. In order to
prevent the peripheral opening ratio from being changed during the
plating process, the second linear actuator 147 may not linearly
move the second controlling plate 180. Thus, the second controlling
plate 180 may be fixed during the plating process.
[0089] The third linear actuator 148 may be configured to linearly
move the third controlling plate 190. Thus, overlapped ratios
between the third controlling holes 192 of the third controlling
plate 190 and the middle first holes 112 of the first shielding
plate 110 may be adjusted to control the middle opening ratio of
the middle first holes 112 in the first shielding plate 110. The
third linear actuator 148 may linearly move the third controlling
plate 190 to provide the edged first holes 112 of the first
shielding plate 110 with the middle opening ratio. In order to
prevent the middle opening ratio from being changed during the
plating process, the third linear actuator 148 may not linearly
move the third controlling plate 190. Thus, the third controlling
plate 190 may be fixed during the plating process.
[0090] Alternatively, the first controlling plate 170 may be fixed.
That is, the first linear actuator 146 may not be connected with
the first controlling plate 170. The second controlling plate 180
may be fixed. That is, the second linear actuator 147 may not be
connected with the second controlling plate 180. The third
controlling plate 190 may be fixed. That is, the third linear
actuator 148 may not be connected with the third controlling plate
190. Further, at least one of the first to third controlling plates
170, 180 and 190 may be rotatably arranged. At least one of the
first to third controlling plates 170, 180 and 190 may be
fixed.
[0091] In example embodiments, the controlling plate may be divided
into the three plates or the five plates. However, the number of
plates that the shielding plate may be divided into is not
restricted to a specific number, and any suitable number of plates
and/or configuration of plates may be used. The number of plates
that the shielding plate may be divided into may be changed in
accordance with the kinds of the objects being plated.
[0092] FIG. 11 is an exploded perspective view illustrating a
shielding unit in accordance with example embodiments.
[0093] A shielding unit 100c of this example embodiment may include
elements substantially the same as those of the shielding unit 100a
in FIG. 7 except for a first shielding plate and a second shielding
plate. Thus, the same reference numerals may refer to the same
elements and any further illustrations with respect to the same
elements may be omitted herein for brevity.
[0094] Referring to FIG. 11, a first shielding plate may be divided
into a single first central shielding plate 110-1 and two first
side shielding plates 110-2 by two parallel vertical lines.
[0095] The first central shielding plate 110-1 may correspond to a
position of the first controlling plate 150. Thus, the first
central shielding plate 110-1 may have a width substantially the
same as that of the first controlling plate 150. Alternatively, the
first central shielding plate 110-1 may have a width different from
that of the first controlling plate 150.
[0096] The first side shielding plates 110-2 may correspond to the
position of the second controlling plates 160. Thus, the first side
shielding plate 110-2 may have a width substantially the same as
that of the second controlling plates 160. Alternatively, the first
side shielding plate 110-2 may have a width different from that of
the second controlling plates 160.
[0097] Linear actuators 143 may be configured to linearly move the
first central shielding plate 110-1 and the first side shielding
plate 110-2. Alternatively, the first central shielding plate 110-1
may be fixed. That is, the linear actuator 143 may not be connected
with the first central shielding plate 110-1. Further, the first
side shielding plates 110-2 may be fixed. That is, the linear
actuators 143 may not be connected with the first side shielding
plates 110-2.
[0098] A second shielding plate may be divided into a single second
central shielding plate 120-1 and two second side shielding plates
120-2 by two parallel vertical lines. The second central shielding
plate 120-1 may have a size substantially the same as that of the
first central shielding plate 110-1. The second side shielding
plates 120-2 may have a size substantially the same as that of the
first side shielding plates 110-2.
[0099] Linear actuators 145 may be configured to linearly move the
second central shielding plate 120-1 and the second side shielding
plate 120-2. Alternatively, the second central shielding plate
120-1 may be fixed. That is, the linear actuator 145 may not be
connected with the second central shielding plate 120-1. Further,
the second side shielding plates 120-2 may be fixed. That is, the
linear actuators 145 may not be connected with the second side
shielding plates 120-2.
[0100] In example embodiments, the shielding plate may be divided
into the three plates. However, the number of plates that the
shielding plate may be divided into is not restricted to a specific
number, and any suitable number of plates and/or configuration of
plates may be used. The number of plates that the shielding plate
may be divided into may be changed in accordance with the kinds of
the objects being plated.
[0101] FIG. 12 is an exploded perspective view illustrating a
shielding unit in accordance with example embodiments, and FIG. 13
is a front view illustrating the shielding unit in FIG. 12.
[0102] Referring to FIGS. 12 and 13, a shielding unit 200 of this
example embodiment may include a first shielding plate 110, a
second shielding plate 120, a first controlling plate 210, a second
controlling plate 220, a third controlling plate 230, a fourth
controlling plate 240, a first linear actuator 250, a second linear
actuator 252, a third linear actuator 254 and a fourth linear
actuator 256.
[0103] In example embodiments, the first shielding plate 110 and
the second shielding plate 120 may have substantially the same
structures as those of the first shielding plate 110 and the second
shielding plate 120 in FIG. 1, respectively. Thus, the same
reference numerals may refer to the same elements and any further
illustrations with respect to the first shielding plate 110 and the
second shielding plate 120 may be omitted herein for brevity.
[0104] The first shielding plate 110 may be divided into a
plurality of regions by a radius line of the first shielding plate
110. In example embodiments, the first shielding plate 110 may be
divided into first to fourth regions by two diameter lines
substantially perpendicular to each other. The first to fourth
regions may have a same quarter shape.
[0105] The first controlling plate 210 may be configured to make
contact with a first region of the first shielding plate 110. The
second controlling plate 220 may be configured to make contact with
a second region of the first shielding plate 110. The third
controlling plate 230 may be configured to make contact with a
third region of the first shielding plate 110. The fourth
controlling plate 240 may be configured to make contact with a
fourth region of the first shielding plate 110. As mentioned above,
because the first to fourth regions may have the same size and
shape, the first to fourth controlling plates 210, 220, 230 and 240
may have a same square shape. That is, the first to fourth
controlling plates 210, 220, 230 and 240 may be formed by dividing
the controlling plate 130 in FIG. 2 along the two diameter
lines.
[0106] The first region may correspond to a central region of the
first shielding plate 110. The second region may correspond to an
edge region of the first shielding plate 110. The third region may
correspond to a middle region between the central region and the
edge region of the first shielding plate 110.
[0107] The first controlling plate 210 may have a plurality of
first controlling holes 212. The second controlling plate 220 may
have a plurality of second controlling holes 222. The third
controlling plate 230 may have a plurality of third controlling
holes 232. The fourth controlling plate 240 may have a plurality of
fourth controlling holes 242. The first controlling holes 212, the
second controlling holes 222, the third controlling holes 232 and
the fourth controlling holes 242 may be arranged spaced apart from
each other in the lengthwise and breadthwise directions by
substantially the same interval. Alternatively, the first
controlling holes 212, the second controlling holes 222, the third
controlling holes 232 and the fourth controlling holes 242 may be
arranged spaced apart from each other in the lengthwise and
breadthwise directions by a different interval.
[0108] The first linear actuator 250 may be configured to linearly
move the first controlling plate 210. The second linear actuator
252 may be configured to linearly move the second controlling plate
220. The third linear actuator 254 may be configured to linearly
move the third controlling plate 230. The fourth linear actuator
256 may be configured to linearly move the fourth controlling plate
240. The linear directions may not be restricted to a specific
direction. For example, the linear directions may include a radius
direction of the first shielding plate 110, a direction
substantially parallel to the diameter line of the first shielding
plate 110, etc. During the plating process, the first to fourth
linear actuators 250, 252, 254 and 256 may not linearly move the
first to fourth controlling plates 210, 220, 230 and 240. Thus, the
first to fourth controlling plates 210, 220, 230 and 240 may be
fixed in the plating process.
[0109] Alternatively, the first controlling plate 210 may be fixed.
That is, the first linear actuator 250 may not be connected with
the first controlling plate 210. The second controlling plate 220
may be fixed. That is, the second linear actuator 252 may not be
connected with the second controlling plate 220. The third
controlling plate 230 may be fixed. That is, the third linear
actuator 254 may not be connected with the third controlling plate
230. The fourth controlling plate 240 may be fixed. That is, the
fourth linear actuator 256 may not be connected with the fourth
controlling plate 240. Further, at least one of the first to fourth
controlling plates 210, 22, 230 and 240 may be rotatably arranged.
At least one of the first to fourth controlling plates 210, 220,
230 and 240 may be fixed.
[0110] In example embodiments, the controlling plate may be divided
into the four plates by the four radius lines. However, the number
of plates that the shielding plate may be divided into is not
restricted to a specific number, and any suitable number of plates
and/or configuration of plates may be used. The number of plates
that the shielding plate may be divided into may be changed in
accordance with the kinds of the objects being plated.
Plating Apparatus
[0111] FIG. 14 is a cross-sectional view illustrating a plating
apparatus including the shielding unit in FIG. 1.
[0112] Referring to FIG. 14, a plating apparatus 300 of this
example embodiment may include a plating bath 310, an anode chamber
320, a cathode chamber 330, a diffusion plate 340 and a shielding
unit 100.
[0113] The plating bath 310 may be configured to receive an
electrolyte. The plating bath 310 may include an inlet 312 through
which the electrolyte may be introduced, and an outlet 314 through
which the electrolyte may be discharged. The inlet 312 may be
formed at a lower surface of the plating bath 310. The outlet 314
may be formed at an upper surface of the plating bath 310. A pump
360 may be connected with the inlet 312 and the outlet 314. The
pump 360 may supply the electrolyte to the plating bath 310.
[0114] The anode chamber 320 may be arranged under the plating bath
310. An anode 322 may be arranged in the anode chamber 320. The
cathode chamber 330 may be arranged over the plating bath 310. A
cathode 332 may be arranged in the cathode chamber 330. The cathode
332 may be rotated by a rotating shaft. A clamshell 336 for
generating en electric field may be arranged on an inner surface of
the cathode chamber 330.
[0115] The anode 322 and the cathode 332 may be connected to a
power source 350. The cathode 332 may be configured to hold an
object. In example embodiments, the object may include a wafer. The
plating apparatus 300 may form a metal layer on the wafer for
forming a wafer level package. The metal layer may include a nickel
layer, a copper layer, a gold layer, etc. Alternatively, the object
may not be restricted to a wafer. For example, the plating
apparatus 300 may be used for a damascene process, a process for
forming a bump, a process for forming a redistribution layer,
etc.
[0116] The diffusion plate 340 may be arranged between the anode
322 and the cathode 332 to uniformly diffuse the electrolyte. A
filter 370 may be arranged between the diffusion plate 340 and the
anode 322 to remove impurities from the electrolyte.
[0117] The shielding unit 100 may be arranged between the diffusion
plate 340 and the cathode 332. The shielding unit 100 may include
elements substantially the same as those of the shielding unit 100
in FIG. 1. Thus, any further illustrations with respect to the
shielding unit 100 may be omitted herein for brevity.
Alternatively, the plating apparatus 300 may include the shielding
unit 100a in FIG. 7, the shielding unit 100b in FIG. 9, the
shielding unit 100c in FIG. 11 or the shielding unit 200 in FIG.
12.
[0118] According to example embodiments, the controlling holes of
the controlling plate may be selectively and partially overlapped
with holes of the shielding plate to control the opening ratios of
the holes. Thus, the electrolyte may be uniformly distributed to
improve a thickness uniformity of a plated layer. Particularly, the
opening ratios of the holes may be controlled by changing a
position of the controlling plate in accordance with the kind of
object being plated so that it may not be required to exchange the
shielding plate for another shielding plate when a different object
is being used.
[0119] The foregoing is illustrative of example embodiments and is
not to be construed as limiting thereof. Although a few example
embodiments have been described, those skilled in the art will
readily appreciate that many modifications are possible in the
example embodiments without materially departing from the novel
teachings and advantages of the present invention. Accordingly, all
such modifications are intended to be included within the scope of
the present invention as defined in the claims. In the claims,
means-plus-function clauses are intended to cover the structures
described herein as performing the recited function and not only
structural equivalents but also equivalent structures. Therefore,
it is to be understood that the foregoing is illustrative of
various example embodiments and is not to be construed as limited
to the specific example embodiments disclosed, and that
modifications to the disclosed example embodiments, as well as
other example embodiments, are intended to be included within the
scope of the appended claims.
* * * * *