U.S. patent application number 15/240423 was filed with the patent office on 2018-02-22 for holes and dimples to control solder flow.
This patent application is currently assigned to SEMICONDUCTOR COMPONENTS INDUSTRIES, LLC. The applicant listed for this patent is SEMICONDUCTOR COMPONENTS INDUSTRIES, LLC. Invention is credited to Dennis Lee CONNER, Stephen ST. GERMAIN, Jay A. YODER.
Application Number | 20180053712 15/240423 |
Document ID | / |
Family ID | 61192122 |
Filed Date | 2018-02-22 |
United States Patent
Application |
20180053712 |
Kind Code |
A1 |
ST. GERMAIN; Stephen ; et
al. |
February 22, 2018 |
HOLES AND DIMPLES TO CONTROL SOLDER FLOW
Abstract
A system, in some embodiments, comprises: a first surface of a
lead frame; a second surface of the lead frame, opposite the first
surface, said second surface having been etched; and one or more
holes passing through said lead frame and coincident with the first
and second surfaces, wherein said one or more holes are adapted to
control fluid flow on said first surface.
Inventors: |
ST. GERMAIN; Stephen;
(Gilbert, AZ) ; CONNER; Dennis Lee; (Peoria,
AZ) ; YODER; Jay A.; (Phoenix, AZ) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SEMICONDUCTOR COMPONENTS INDUSTRIES, LLC |
Phoenix |
AZ |
US |
|
|
Assignee: |
SEMICONDUCTOR COMPONENTS
INDUSTRIES, LLC
Phoenix
AZ
|
Family ID: |
61192122 |
Appl. No.: |
15/240423 |
Filed: |
August 18, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01L 21/4842 20130101;
H01L 23/49503 20130101; H01L 2224/40245 20130101; H01L 2224/29124
20130101; H01L 24/37 20130101; H01L 24/83 20130101; H01L 2224/26175
20130101; H01L 24/40 20130101; H01L 2224/84801 20130101; H01L 24/29
20130101; H01L 2224/32245 20130101; H01L 2924/0715 20130101; H01L
2224/29191 20130101; H01L 24/32 20130101; H01L 2924/1203 20130101;
H01L 21/4828 20130101; H01L 2224/29299 20130101; H01L 2924/1304
20130101; H01L 2224/40095 20130101; H01L 2224/83801 20130101; H01L
2224/8385 20130101; H01L 2224/37011 20130101; H01L 2224/83192
20130101; H01L 2224/83815 20130101; H01L 2224/92246 20130101; H01L
23/49513 20130101; H01L 23/49575 20130101; H01L 23/49541 20130101;
H01L 2224/83805 20130101; H01L 24/73 20130101; H01L 2224/29199
20130101; H01L 2224/84815 20130101; H01L 2924/0665 20130101; H01L
2224/2919 20130101; H01L 2224/291 20130101; H01L 2224/37099
20130101; H01L 2224/73263 20130101; H01L 2924/07025 20130101; H01L
24/92 20130101; H01L 23/49548 20130101; H01L 24/84 20130101; H01L
2924/1304 20130101; H01L 2924/00012 20130101; H01L 2924/1203
20130101; H01L 2924/00012 20130101; H01L 2224/37099 20130101; H01L
2924/00014 20130101; H01L 2224/29199 20130101; H01L 2924/00014
20130101; H01L 2224/29299 20130101; H01L 2924/00014 20130101; H01L
2224/2919 20130101; H01L 2924/07025 20130101; H01L 2924/00014
20130101; H01L 2224/29124 20130101; H01L 2924/00014 20130101; H01L
2224/2919 20130101; H01L 2924/0715 20130101; H01L 2924/00014
20130101; H01L 2224/291 20130101; H01L 2924/01322 20130101; H01L
2924/014 20130101; H01L 2924/00014 20130101; H01L 2224/2919
20130101; H01L 2924/0665 20130101; H01L 2924/00014 20130101 |
International
Class: |
H01L 23/495 20060101
H01L023/495; H01L 23/00 20060101 H01L023/00; H01L 21/48 20060101
H01L021/48 |
Claims
1. A system, comprising: a first surface of a lead frame; a second
surface of the lead frame, opposite the first surface, said second
surface having been etched; one or more cylindrical holes passing
through said lead frame and coincident with the first and second
surfaces; and fluid on the first surface, the fluid at least
partially encircling an aperture of said one or more holes, wherein
said one or more holes are adapted to control flow of the fluid on
said first surface.
2. The system of claim 1, wherein said fluid comprises reflowed
solder.
3. The system of claim 1, wherein said second surface comprises a
half-etched area.
4. The system of claim 1, wherein said fluid has a distribution on
the first surface that is influenced at least in part by said one
or more holes.
5. The system of claim 1, wherein said fluid partially fills said
one or more holes.
6. (canceled)
7. The system of claim 1, wherein said fluid straddles at least one
aperture of said one or more holes.
8. The system of claim 1, wherein said fluid is selected from the
group consisting of epoxy, polyimide, silicone adhesives, hybrid
organic adhesives, soft solder, and eutectic solder.
9. The system of claim 1, further comprising a die coupled to the
first surface using solder, a position of the die on the first
surface is influenced at least in part by said one or more
holes.
10. The system of claim 9, further comprising a clip coupling said
lead frame to the die using solder, said clip having one or more
additional holes, a position of the clip relative to the die
determined at least in part by said one or more additional
holes.
11. The system of claim 1, further comprising one or more dimples
positioned on said first surface and opposite the second surface,
said one or more dimples are adapted to control said fluid flow on
the first surface.
12. A system, comprising: a lead frame having a lead frame surface;
one or more dimples formed upon the lead frame surface, said one or
more dimples adapted to control fluid flow on said lead frame
surface; and fluid on the lead frame surface, said fluid straddling
at least one aperture of the one or more dimples.
13. The system of claim 12, further comprising a second lead frame
surface opposite the lead frame surface, said second lead frame
surface having been half-etched.
14. The system of claim 12, wherein a distribution of said fluid on
the lead frame surface is determined at least in part by said one
or more dimples.
15. The system of claim 12, further comprising a die coupled to the
lead frame surface using said fluid, a position of the die on the
lead frame surface is influenced at least in part by said one or
more dimples.
16. The system of claim 12, further comprising one or more holes
passing through the lead frame, said one or more holes adapted to
control flow of said fluid on the lead frame surface.
17. A method, comprising: etching at least a portion of a first
surface of a lead frame; etching one or more holes and one or more
dimples on a second surface of the lead frame, said first and
second surfaces opposing each other, said one or more holes and one
or more dimples configured to control solder flow; applying solder
on the second surface of the lead frame; and reflowing said solder,
wherein the at least one dimple has an aperture with a smaller
diameter than an aperture of said at least one hole.
18. The method of claim 17, further comprising said one or more
holes and one or more dimples controlling flow of said reflowed
solder.
19. (canceled)
20. The method of claim 17, further comprising forming at least one
hole or dimple in a clip and using said clip to electrically couple
a portion of said lead frame to a die.
Description
BACKGROUND
[0001] Semiconductor packages include various components, such as
lead frames, die, and different types of bonds. Often, these and
other such components are coupled together using solder or a
similar, viscous substance. Controlling the flow of solder on
component surfaces is important, because insufficient solder in
certain locations results in poor electrical connections, and
because the presence of solder in other locations results in
electrical shorts or other problems. Such control over solder flow,
however, is difficult to achieve.
SUMMARY
[0002] At least some of the embodiments disclosed herein are
directed to a system, comprising: a first surface of a lead frame;
a second surface of the lead frame, opposite the first surface,
said second surface having been etched; and one or more holes
passing through said lead frame and coincident with the first and
second surfaces, wherein said one or more holes are adapted to
control fluid flow on said first surface. One or more of these
embodiments may be supplemented using one or more of the following
concepts, in any order and in any combination: wherein said fluid
comprises reflowed solder; wherein said second surface comprises a
half-etched area; further comprising fluid on the first surface,
said fluid having a distribution on the first surface that is
influenced at least in part by said one or more holes; further
comprising fluid on the first surface, said fluid partially filling
said one or more holes; further comprising fluid on the first
surface, said fluid at least partially encircling an aperture of
said one or more holes; further comprising fluid on the first
surface, said fluid straddling an aperture of said one or more
holes; further comprising fluid on the first surface, wherein said
fluid is selected from the group consisting of epoxy, polyimide,
silicone adhesives, hybrid organic adhesives, soft solder, and
eutectic solder; further comprising a die coupled to the first
surface using solder, a position of the die on the first surface is
influenced at least in part by said one or more holes; further
comprising a clip coupling said lead frame to the die using solder,
said clip having one or more additional holes, a position of the
clip relative to the die determined at least in part by said one or
more additional holes; further comprising one or more dimples
positioned on said first surface and opposite the second surface,
said one or more dimples are adapted to control said fluid flow on
the first surface.
[0003] At least some embodiments are directed to a system,
comprising: a lead frame having a lead frame surface; and one or
more dimples formed upon the lead frame surface, said one or more
dimples adapted to control fluid flow on said lead frame surface.
One or more of these embodiments may be supplemented using one or
more of the following concepts, in any order and in any
combination: further comprising a second lead frame surface
opposite the lead frame surface, said second lead frame surface
having been half-etched; further comprising fluid on the lead frame
surface, a distribution of said fluid on the lead frame surface
determined at least in part by said one or more dimples; further
comprising a die coupled to the lead frame surface using fluid, a
position of the die on the lead frame surface is influenced at
least in part by said one or more dimples; further comprising one
or more holes passing through the lead frame, said one or more
holes adapted to control fluid flow on the lead frame surface.
[0004] At least some embodiments are directed to a method,
comprising: etching at least a portion of a first surface of a lead
frame; etching one or more holes or dimples on a second surface of
the lead frame, said first and second surfaces opposing each other,
said one or more holes or dimples configured to control solder
flow; applying solder on the second surface of the lead frame; and
reflowing said solder. One or more of these embodiments may be
supplemented using one or more of the following concepts, in any
order and in any combination: further comprising said one or more
holes or dimples controlling flow of said reflowed solder; wherein
etching one or more holes or dimples comprises etching at least one
hole and at least one dimple, and wherein said at least one dimple
has an aperture with a smaller diameter than an aperture of said at
least one hole; further comprising forming at least one hole or
dimple in a clip and using said clip to electrically couple a
portion of said lead frame to a die.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] In the drawings:
[0006] FIG. 1A is a top-down view of an illustrative lead frame
having multiple holes.
[0007] FIG. 1B is a bottom-up view of the lead frame of FIG.
1A.
[0008] FIG. 1C is a side view of the lead frame of FIG. 1A.
[0009] FIG. 2A is a perspective view of the lead frame surface
depicted in FIG. 1A.
[0010] FIG. 2B is a perspective view of the lead frame surfaces
depicted in FIG. 1B.
[0011] FIG. 3 is a side view of a lead frame having a hole formed
therein and a die and die attach material positioned thereupon.
[0012] FIG. 4A is a top-down view of a portion of a lead frame
having multiple holes and die attach material deposited
thereupon.
[0013] FIGS. 4B and 4C are top-down views of the portion of the
lead frame depicted in FIG. 4A, with the die attach material having
been reflowed.
[0014] FIG. 5A is a top-down view of an illustrative lead frame
having multiple dimples.
[0015] FIG. 5B is a bottom-up view of the lead frame of FIG.
5A.
[0016] FIG. 6A is a perspective view of the lead frame surface
depicted in FIG. 5A.
[0017] FIG. 6B is a perspective view of the lead frame surfaces
depicted in FIG. 5B.
[0018] FIG. 7 is a side view of a lead frame having a dimple formed
therein and a die and die attach material positioned thereupon.
[0019] FIGS. 8A and 8C are top-down views of portions of lead
frames having dimples and die attach material deposited
thereupon.
[0020] FIGS. 8B and 8D are top-down views of the portions of lead
frames depicted in FIGS. 8A and 8C, respectively, with the die
attach material having been reflowed.
[0021] FIGS. 9A-9E are perspective views of an illustrative lead
frame die attach and clip bonding process, in accordance with
various embodiments.
[0022] FIG. 10 is a flow diagram of an illustrative process in
accordance with various embodiments.
[0023] It should be understood that the specific embodiments given
in the drawings and detailed description thereto do not limit the
disclosure. On the contrary, they provide the foundation for one of
ordinary skill to discern the alternative forms, equivalents, and
modifications that are encompassed together with one or more of the
given embodiments in the scope of the appended claims.
DETAILED DESCRIPTION
[0024] Disclosed herein are lead frames having holes, dimples, or
both formed therein to control the flow of die attach material
(e.g., epoxy, polyimide, silicone or hybrid organic adhesives, soft
or eutectic solders). By controlling the flow of die attach
material, the undesirable effects of unrestrained die attach
material flow--such as electrical shorts in some areas and/or poor
electrical connections in other areas--are mitigated.
[0025] FIG. 1A is a top-down view of an illustrative lead frame
102. Lead frames are often composed of copper or copper-based
alloys and are used to incorporate electronics--for example,
integrated circuits and discrete devices (e.g., transistors,
diodes)--into protective packages. The lead frames enable
electrical signals to flow between the electronic device
encapsulated within the package and electronic devices, such as a
printed circuit board, outside the package. The lead frame 102
depicted in FIG. 1A and, more generally, the lead frames depicted
in any portion of this disclosure do not limit the scope of this
disclosure. The holes and dimples described herein may be formed in
any suitable type of lead frame to control the flow of die attach
material.
[0026] Still referring to FIG. 1A, the lead frame 102 comprises
multiple holes 104. The holes 104 pass through the thickness of the
lead frame 102 such that the apertures of each hole are on opposing
surfaces of the lead frame 102. The holes 104 may be of any
suitable diameter (e.g., a range of 0.1270 to 0.3048 mm, inclusive)
depending on material thickness to achieve a through hole during
the etching process, and may be formed in any suitable number,
arrangement, and pitch. In at least some embodiments, the holes 104
are arranged between the area in which die attach material (e.g.,
solder) is to be deposited and the area that is to be protected
from die attach material flow. Furthermore, the holes 104 may be
formed in any suitable area of the lead frame 102, including leads,
die flags, etc. The holes 104 preferably are formed during the lead
frame etching process. Their sizes, quantities, and locations are
determined by the masks used during the etching process. When die
attach material is reflowed, the holes 104 (and dimples, which are
described below) draw the die attach material toward themselves and
away from the areas to be protected from the reflowed die attach
material.
[0027] In at least some embodiments, the lead frame 102 includes at
least one trench 106. Like the holes 104, one purpose of the trench
106 is to control the flow of die attach material. However, unlike
the holes 104, the trench 106 does not pass completely through the
thickness of the lead frame 102. When die attach material, such as
solder, is reflowed, it approaches the trench 106 but--due to its
tensile properties--does not enter the trench 106. Its resistance
to flowing into the trench 106 helps maintain the desired position
of the die or other component that is coupled to the die attach
material. Stated another way, the trench 106 controls the flow of
the die attach material and, because the die attach material flow
is controlled, the die that is coupled to the die attach material
is precluded from sliding or moving into undesirable positions.
Instead, the die remains in its proper position.
[0028] FIG. 1B is a bottom-up view of the lead frame 102 of FIG.
1A. This view of the lead frame 102 depicts the holes 104,
since--as explained above--the holes 104 pass completely through
the lead frame 102. However, this view does not depict the trench
106, since--as explained--the trench 106 does not pass completely
through the lead frame 102. In at least some embodiments, the holes
104 are formed on areas of the lead frame 102 that have been
half-etched. The term "half-etched," as used herein, refers to a
degree of etching that causes an area of a lead frame 102 to be
approximately half the thickness (i.e., between 25 and 75%,
inclusive) of another, non-half-etched area of the lead frame
(depicted as numerals 108 in FIG. 1B). Unlike the holes 104, which
are formed on areas of the lead frames that have been half-etched,
the trench 106 is formed on an area of the top surface of the lead
frame (FIG. 1A) that is opposite an area of the bottom surface that
is not half-etched--e.g., one of the areas 108, as shown. Were the
trench 106 formed in an area that is half-etched, it would create a
significant, continuous aperture in the lead frame and would thus
compromise the structural integrity of the lead frame. The holes
104, though formed in half-etched areas, do not compromise the
structural integrity of the lead frame because they are
comparatively small and are separated from each other.
[0029] FIG. 1C is a side view of the lead frame 102 of FIG. 1A from
the perspective of numerals 110. As shown, the thickness of the
lead frame 102 in areas that have been half-etched (marked as
numeral 112) is approximately half that of areas that have not been
half-etched (marked as numeral 108). To provide additional clarity,
FIG. 2A is a perspective view of the lead frame surface depicted in
FIG. 1A, and FIG. 2B is a perspective view of the lead frame
surfaces depicted in FIG. 1B.
[0030] FIG. 3 is a side view of an illustrative lead frame 300
having a hole 302 formed in a half-etched area 304 and further
having a die 306 and die attach material 308 positioned thereupon.
The lead frame 300 also comprises a non-half-etched area 310. The
die attach material 308, and, more generally, any die attach
material described herein may comprise epoxy, polyimide, silicone
or hybrid organic adhesives, and/or soft or eutectic solders, and
it may be deposited in gel, paste, film, tape, or solder form. Any
such die attach material, when reflowed, may be referred to herein
as "fluid," irrespective of the viscosity of the material.
[0031] When the die attach material 308 is reflowed, its tensile
characteristics will either prevent the material 308 from entering
the hole 302, or, in some cases, the material 308 will enter the
hole 302 but will not pass entirely through the hole 302. In some
cases, the material 308 may encircle part or all of the aperture of
the hole 302, or it may straddle the aperture of the hole 302
(i.e., cover the aperture of the hole without entering it). At
least some such flow possibilities are described with respect to
FIGS. 4A-4C. Specifically, FIG. 4A is a top-down view of a portion
of an illustrative lead frame 400 having multiple holes 402 and die
attach material 404 deposited thereupon (e.g., printed solder). The
die attach material 404 is caused to flow--for instance, by a
reflow process. As a result, the die attach material 404 may flow
and eventually settle as depicted in FIG. 4B, which shows the
material 404 partially encircling the holes 402. The tensile
characteristics of the die attach material 404 preclude the
material 404 between the holes from flowing substantially beyond
the area of the holes. FIG. 4C is another top-down view of the
portion of the lead frame 400 depicted in FIG. 4A, with the die
attach material 404 having been reflowed in a different pattern. As
shown, the material 404 straddles the holes 402 without
substantially entering the holes 402, or, in some cases, without
entering the holes 402 more than approximately halfway. Various
such flow patterns are possible depending on a variety of factors,
but in each case, the holes 402 effectively control solder flow and
thus mitigate electrical shorts and/or poor electrical
connections.
[0032] FIG. 5A is a top-down view of an illustrative lead frame 502
having multiple dimples 504. Dimples differ from holes in that they
do not pass completely through the lead frame on which they are
formed. Additionally, they may be smaller in diameter than holes,
since the etching process generally will etch less deeply when the
aperture diameter is smaller. The specific aperture diameter
threshold above which a particular etching process will create a
hole rather than a dimple is application-specific. As with holes,
however, the dimples 504 can be created in any suitable number,
arrangement, pitch, location, size, and shape. For example, holes
and dimples may be etched as semi-circles, ovals, rectangles, and
the like. The typical dimple 504 will have an aperture diameter
ranging between 0.0254 mm and 0.1016 mm, inclusive, depending on
material thickness, although the scope of this disclosure is not
limited as such. The lead frame 502 may additionally include a
trench 506.
[0033] FIG. 5B is a bottom-up view of the lead frame 502 of FIG.
5A. The dimples 504 are formed in half-etched areas (as opposed to
non-half-etched areas 508), but because the dimples 504 do not pass
through the lead frame, they are not visible in FIG. 5B. The scope
of disclosure is not limited to forming dimples only in half-etched
areas; dimples may be formed in non-half-etched areas 508. To
provide additional clarity, FIGS. 6A and 6B show perspective views
of the lead frame 502 depicted in FIGS. 5A and 5B.
[0034] FIG. 7 is a side view of an illustrative lead frame 700
having a dimple 702 formed therein and a die 708 and die attach
material 706 positioned thereupon. The dimple 702 is formed in a
half-etched area 704, and the lead frame 700 also includes a
non-half-etched area 710. In at least some embodiments, the die
attach material 706 is deposited directly into or over the dimple
702. When the die attach material 706 is reflowed, it fills the
dimple 702. A sufficient amount of die attach material 706 is
preferably deposited so that it fills the dimple 702 and overflows
outside the dimple 702 so that a proper electrical connection may
be formed with the die 708. However, the scope of disclosure is not
limited to using the dimple 702 as shown. For example, the dimple
702 may be used as the hole 302 is used in FIG. 3, meaning that the
die attach material is deposited adjacent to the dimple 702 and
permitted to flow toward the dimple 702. The dimple 702, together
with the tensile properties of the die attach material and any
other dimples that may be positioned in the vicinity of the dimple
702, preclude the die attach material from flowing substantially
beyond the dimple(s).
[0035] FIG. 8A is a top-down view of a portion of a lead frame 800
having a dimple 802 and die attach material 804 thereupon. As
shown, the die attach material is printed or otherwise deposited
directly on or above the dimple 802. When reflowed, the die attach
material 804 may flow in the pattern shown in FIG. 8B. In FIG. 8B,
the die attach material 804 fills some or all of the dimple 802.
FIG. 8C is another top-down view of a portion of the lead frame 800
having a dimple 802 and die attach material 804 deposited
thereupon. In FIG. 8C, the die attach material 804 is deposited
adjacent to, rather than on top of, the dimple 802. FIG. 8D shows
the flow pattern of the die attach material 804 when reflowed. As
shown, the reflowed die attach material 804 encircles at least part
of the dimple aperture and may at least partially fill the dimple
802. The scope of disclosure is not limited to any particular flow
pattern, and no particular flow pattern is guaranteed to result
from any particular type or configuration of die attach material.
For example, when the die attach material 804 in FIG. 8C is
reflowed, it may produce a flow pattern like that in FIG. 8B rather
than that depicted in FIG. 8D. Any and all such variations are
contemplated and fall within the scope of this disclosure.
[0036] FIGS. 9A-9E are perspective views of an illustrative lead
frame die attach and clip bonding process, in accordance with
various embodiments. Specifically, FIG. 9A depicts a lead frame 900
having a plurality of holes and/or dimples 902 and a trench 904. As
explained above, the holes and/or dimples 902 are etched at the
same time that the lead frame 900 is etched using the appropriate
mask(s).
[0037] FIG. 9B depicts die attach material 906 having been
deposited adjacent to, or directly on, the holes and/or dimples
902. FIG. 9C depicts multiple die 908 being positioned on the lead
frame 900. As previously explained, the trench 904 can help one of
the die 908 maintain proper position and prevent the die from
sliding, and so one of the die 908 is positioned along the trench
904, as shown. FIG. 9D shows additional die attach material 910
being deposited atop the multiple die 908. FIG. 9E depicts clips
912, 914 being coupled to the die attach material on the lead frame
900 and on the die 908, as shown. This coupling establishes
electrical connections between the lead frame 900 and the multiple
die 908.
[0038] In addition, FIG. 9E depicts the clip 914 having multiple
holes 916, each of which is positioned to align with one or more
depositions of die attach material 910 atop the die 908. When
reflowed, the die attach material 910 atop the die 908 flows
through the holes 916 instead of being squeezed out from between
the edges of the die 908 and the clip 914. Due to these holes 916,
the clip 914--like the die 908--remains in position and does not
slide. In some embodiments, dimples may be formed in the clip 914
in addition to, or in lieu of, the holes 916.
[0039] FIG. 10 is a flow diagram of an illustrative process 1000 in
accordance with various embodiments. The process 1000 begins by
etching at least a portion of a first surface of a lead frame (step
1002). This step includes half-etching at least a portion of the
first surface. The process 1000 continues by etching one or more
holes or dimples on a second surface of the lead frame (step 1004).
The lead frame may have holes, dimples, or a combination thereof.
As explained, the holes preferably are formed in areas that have
been half-etched so that the holes pass completely through the lead
frame. Dimples preferably are formed in half-etched areas as well.
The scope of disclosure, however, includes forming dimples in
non-half-etched areas. The process 1000 also includes applying die
attach material on the second surface of the lead frame in
selectively targeted areas (step 1006). The die attach material is
then reflowed, and the flow of the die attach material is
controlled by the holes and/or dimples (step 1008). The method 1000
may be modified by adding, removing, modifying, or rearranging one
or more steps.
[0040] Numerous other variations and modifications will become
apparent to those skilled in the art once the above disclosure is
fully appreciated. It is intended that the following claims be
interpreted to embrace all such variations, modifications and
equivalents. In addition, the term "or" should be interpreted in an
inclusive sense.
* * * * *