U.S. patent application number 11/495789 was filed with the patent office on 2007-02-08 for electromechanical structure and method of making same.
Invention is credited to Joseph F. Burke, Thomas G. Campbell, Pat Anthony Coppola, Brian Farrell, John J. JR. Gannon, Sean Gerald O'Reilly.
Application Number | 20070030681 11/495789 |
Document ID | / |
Family ID | 37709251 |
Filed Date | 2007-02-08 |
United States Patent
Application |
20070030681 |
Kind Code |
A1 |
Farrell; Brian ; et
al. |
February 8, 2007 |
Electromechanical structure and method of making same
Abstract
An electromechanical structure includes a core and a plurality
of conductive pins through the core. The pins are configured to
form a signal distribution network from a first side of the core to
a second side of the core.
Inventors: |
Farrell; Brian; (Quincy,
MA) ; Gannon; John J. JR.; (Sudbury, MA) ;
Campbell; Thomas G.; (Concord, MA) ; Coppola; Pat
Anthony; (Bedford, MA) ; O'Reilly; Sean Gerald;
(Brighton, MA) ; Burke; Joseph F.; (Atkinson,
NH) |
Correspondence
Address: |
IANDIORIO & TESKA;INTELLECTUAL PROPERTY LAW ATTORNEYS
260 BEAR HILL ROAD
WALTHAM
MA
02451-1018
US
|
Family ID: |
37709251 |
Appl. No.: |
11/495789 |
Filed: |
July 28, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60704089 |
Jul 29, 2005 |
|
|
|
Current U.S.
Class: |
362/257 |
Current CPC
Class: |
H05K 3/0058 20130101;
H05K 1/147 20130101; H01Q 1/286 20130101; H05K 3/36 20130101; H05K
2201/029 20130101; H05K 3/0064 20130101; H05K 3/3447 20130101; H05K
1/038 20130101; H05K 3/4046 20130101; H05K 1/00 20130101; H05K
2201/0281 20130101; H05K 2201/10303 20130101; H05K 2201/0116
20130101; H01Q 21/065 20130101; B64D 43/00 20130101 |
Class at
Publication: |
362/257 |
International
Class: |
F21S 6/00 20060101
F21S006/00 |
Claims
1. An electromechanical structure comprising: a core; a plurality
of conductive pins through the core; the pins configured to form a
signal distribution network from a first side of the core to a
second side of the core.
2. The structure of claim 1 in which there is an array of radiating
elements on the first side of the core each connected to one end of
a pin and a printed circuit board on a second side of the core
electrically connected to the other ends of the pins forming a
notional antenna subsystem.
3. The structure of claim 2 further including a composite member
comprising: plies of fabric, resin impregnating the plies of
fabric, at least one ply including signal transmission elements
integrated therewith and connected between the printed circuit
board and electronics for the notional antenna system.
4. The structure of claim 3 in which said core is a dielectric.
5. The structure of claim 4 in which the dielectric core is
air.
6. The structure of claim 5 in which the dielectric core includes a
dielectric support mechanism.
7. The structure of claim 6 in which the dielectric support
mechanism is a dielectric honeycomb structure.
8. The structure of claim 6 in which the dielectric support
mechanism is a dielectric truss structure.
9. The structure of claim 8 in which the truss structure includes a
network of dielectric pins forming the truss structure.
10. The structure of claim 4 in which the dielectric core is a low
density material.
11. The structure of claim 4 in which the dielectric core is
foam.
12. The structure of claim 4 in which the dielectric core is a
polymer.
13. The structure of claim 4 further including a radome layer over
the radiating elements.
14. The structure of claim 13 in which the radome layer is made of
astroquartz.
15. The structure of claim 2 further including a ground plane
between the core and the printed circuit board.
16. The structure of claim 15 in which the ground plane is a
composite layer including plies of conductive fibers impregnated
with a resin.
17. The structure of claim 16 in which the fibers are carbon.
18. The structure of claim 15 further including a structural layer
between the ground plane and the printed circuit board.
19. The structure of claim 18 in which the structural layer
includes a foam sub-layer on a composite sub-layer.
20. The structure of claim 19 in which the composite sub-layer
includes fibers impregnated with a resin.
21. The structure of claim 20 in which the composite sub-layer
fibers are carbon.
22. The structure of claim 15 in which the ground plane includes
holes therethrough for the conductive pins.
23. The structure of claim 22 in which the conductive pins are
insulated.
24. The structure of claim 22 in which the holes provide clearance
between the conductive pins and the ground plane.
25. The structure of claim 1 in which the pins are solid and made
of a metal alloy.
26. The structure of claim 25 in which the metal alloy includes
copper.
27. The structure of claim 1 in which the pins include a composite
core surrounded by metal coating.
28. The structure of claim 1 in which the pins include a central
conductor surrounded by a dielectric material surrounded by a
coaxial shield conductor.
29. The structure of claim 1 in which the pins are tubular.
30. The structure of claim 1 in which the pins are configured to
provide sidewall metallization around a cavity of radiating
element.
31. The structure of claim 2 in which the radiating elements are
printed on the core.
32. The structure of claim 2 in which the pins are inserted through
holes drilled in the core.
33. The structure of claim 30 in which the pins are first inserted
through the holes formed in the dielectric core and the radiating
elements are then printed over the pins.
34. The structure of claim 3 in which the signal transmission
elements are wires woven into the at least one ply of the composite
member.
35. The structure of claim 34 in which said wires are
insulated.
36. The structure of claim 1 in which the core is a solid composite
component made of a number of plies of fabric impregnated with a
resin.
37. An electromechanical structure comprising: a low density
dielectric core; an array of radiating elements one side of the
core; a printed circuit board on an opposing side of the core; and
a plurality of conductive pins through the core and insulated
therefrom, the pins configured to form a signal distribution
network from the radiating elements to the printed circuit
board.
38. A method of fabricating an electromechanical structure, the
method comprising: inserting a plurality of conductive pins through
a core; and configuring the pins to form a signal distribution
network from a first side of the core to a second side of the
core.
39. The method of claim 38 in which there is an array of radiating
elements on the first side of the core each connected to one end of
a pin and a printed circuit board on a second side of the core
electrically connected to the other ends of the pins forming a
notional antenna subsystem.
40. The method of claim 39 further including a composite member
comprising: plies of fabric, resin impregnating the plies of
fabric, at least one ply including signal transmission elements
integrated therewith and connected between the printed circuit
board and electronics for the notional antenna system.
41. The method of claim 39 in which said core is a dielectric.
42. The method of claim 41 in which the dielectric core is air.
43. The method of claim 42 in which the dielectric core includes a
dielectric support mechanism.
44. The method of claim 43 in which the dielectric support
mechanism is a dielectric honeycomb structure.
45. The method of claim 43 in which the dielectric support
mechanism is a dielectric truss structure.
46. The method of claim 45 in which the truss structure includes a
network of dielectric pins forming the truss structure.
47. The method of claim 41 in which the dielectric core is a low
density material.
48. The method of claim 41 in which the dielectric core is
foam.
49. The method of claim 41 in which the dielectric core is a
honeycomb structure.
50. The method of claim 39 further including disposing a radome
layer over the radiating elements.
51. The method of claim 50 in which the radome layer is made of
astroquartz.
52. The method of claim 39 further including disposing a ground
plane between the core and the printed circuit board.
53. The method of claim 52 in which the ground plane is a composite
layer including plies of conductive fibers impregnated with a
resin.
54. The method of claim 53 in which the fibers are carbon.
55. The method of claim 52 further including disposing a structural
layer between the ground plane and the printed circuit board.
56. The method of claim 55 in which the structural layer includes a
foam sub-layer on a composite sub-layer.
57. The method of claim 56 in which the composite sub-layer
includes fibers impregnated with a resin.
58. The method of claim 57 in which the composite sub-layer fibers
are carbon.
59. The method of claim 52 in which the ground plane includes holes
therethrough for the conductive pins.
60. The method of claim 59 in which the conductive pins are
insulated.
61. The method of claim 59 in which the holes provide clearance
between the conductive pins and the ground plane.
62. The method of claim 38 in which the pins are solid and made of
a metal alloy.
63. The method of claim 62 in which the metal alloy includes
copper.
64. The method of claim 38 in which the pins include a composite
core surrounded by metal coating.
65. The method of claim 38 in which the pins include a central
conductor surrounded by a composite dielectric material surrounded
by a shield.
66. The method of claim 38 in which the pins are tubular.
67. The method of claim 38 in which the pins are configured to
provide sidewall metallization around a cavity of a radiating
element.
68. The method of claim 39 further including printing the radiating
elements on the core.
69. The method of claim 39 further including inserting the pins
through holes drilled in the core.
70. The method of claim 69 in which the pins are first inserted
through the holes formed in the dielectric core and the radiating
elements are then printed over the pins.
71. The method of claim 40 in which the signal transmission
elements are wires woven into the at least one ply of the composite
member.
72. The method of claim 71 in which said wires are insulated.
73. The method of claim 38 in which the core is a solid composite
component made of a number of plies of fabric impregnated with a
resin.
74. A method of fabricating an electromechanical structure, the
method comprising: inserting a plurality of conductive pins through
a low density dielectric core; insulating the pins from the low
density dielectric core and a ground plane; disposing an array of
radiating elements one side of the core; disposing a printed
circuit board on an opposing side of the core; and configuring the
pins to form a signal distribution network from the radiating
elements to the printed circuit board.
75. An electromechanical structure comprising: a core; a plurality
of conductive pins through the core; the pins configured to form a
signal distribution network from a first side of the core to a
printed circuit board on a second side of the core.
76. The structure of claim 75 further including a ground plane
between the core and the printed circuit board.
77. The structure of claim 76 in which the ground plane is a thin
layer between the core and the printed circuit board.
78. The structure of claim 77 in which the thin layer is
copper.
79. The structure of claim 77 in which the core is a dielectric
core.
80. The structure of claim 79 in which there is an array of
radiating elements on the first side of the core each connected to
one end of a pin.
81. The structure of claim 80 in which the printed circuit board is
electrically connected to the other ends of the pins forming a
notional antenna subsystem.
82. The structure of claim 81 in which the notional antenna
subsystem is configured to be affixed to an aircraft panel.
83. The structure of claim 81 in which the dielectric core is
air.
84. The structure of claim 83 in which the dielectric core includes
a dielectric support mechanism.
85. The structure of claim 84 in which the dielectric support
mechanism is a dielectric honeycomb structure.
86. The structure of claim 84 in which the dielectric support
mechanism is a dielectric truss structure.
87. The structure of claim 86 in which the truss structure includes
a network of dielectric pins forming the truss structure.
88. The structure of claim 81 in which the dielectric core is a low
density material.
89. The structure of claim 81 in which the dielectric core is
foam.
90. The structure of claim 81 in which the dielectric core is a
polymer.
91. The structure of claim 81 further including a radome layer over
the radiating elements.
92. The structure of claim 91 in which the radome layer is made of
astroquartz.
93. The structure of claim 77 in which the ground plane includes
holes therethrough for the conductive pins.
94. The structure of claim 77 in which the conductive pins are
insulated.
95. The structure of claim 93 in which the holes provide clearance
between the conductive pins and the ground plane.
96. The structure of claim 75 in which the pins are solid and made
of a metal alloy.
97. The structure of claim 96 in which the metal alloy includes
copper.
98. The structure of claim 75 in which the pins include a composite
core surrounded by metal coating.
99. The structure of claim 75 in which the pins include a central
conductor surrounded by a dielectric material surrounded by a
coaxial shield conductor.
100. The structure of claim 75 in which the pins are tubular.
101. The structure of claim 75 in which the pins are configured to
provide sidewall metallization around a cavity of radiating
element.
102. The structure of claim 81 in which the radiating elements are
printed on the core.
103. The structure of claim 81 in which the pins are inserted
through holes drilled in the core.
104. The structure of claim 103 in which the pins are first
inserted through the holes formed in the dielectric core and the
radiating elements are then printed over the pins.
105. A method of fabricating an electromechanical structure, the
method comprising: pre-drilling pilot holes in a dielectric core;
pre-forming pilot holes in a ground plane; pre-drilling holes in a
printed circuit board; and inserting a plurality of conductive pins
through each of the printed circuit board, the ground plane, and
the dielectric core to bond together the dielectric core, ground
plane and printed circuit board.
106. A method of fabricating an electromechanical structure, the
method comprising: pre-drilling pilot holes in a ground plane
attached to a printed circuit board; bonding the ground plane and
printed circuit board to a dielectric core; drilling holes through
the printed circuit board and dielectric core coinciding with the
pre-drilled pilot holes in the ground plane; and inserting a
plurality of conductive pins through each of the printed circuit
board, the ground plane, and the dielectric core.
Description
RELATED APPLICATIONS
[0001] This application claims the benefit of and priority to U.S.
Provisional Application No. 60/704,089, filed Jul. 29, 2005, which
is hereby incorporated herein by reference.
FIELD OF THE INVENTION
[0002] This subject invention relates to a dual function composite
system and electromechanical structures, and in one example,
multilayer printed circuit boards which can replace conventional
printed circuit boards.
BACKGROUND OF THE INVENTION
[0003] Composite technology offers a wide variety of advantages
including a high strength to weight ratio. Thus, composite systems
are now used in mobile platforms such as aircraft and spacecraft
for a variety of structural components.
[0004] Those skilled in the art are also studying higher and more
complex levels of system integration. In but one example, it would
be useful to integrate antennas into composite aircraft wing panels
or other aircraft structures such as a panel of a fuselage or a
portion of a door, or to apply or attach antennas to an aircraft.
Current design challenges include how to provide sufficient
dielectric separation between the radiating antenna elements and
the ground plane of the antenna. Plated through hole printed
circuit board technology cannot be used in connection with such
advanced systems due to the inability to form via structures in
lightweight dielectric materials (e.g. open cell foams), and/or the
inability to form very high aspect ratio vias in dielectric
materials. Also, it would be desirable to integrate the electrical
bus extending between the antenna and this electronic subsystem
into the aircraft structure. Otherwise, the weight savings provided
by composite technology will suffer and the cost of using composite
technology will be prohibitive.
SUMMARY OF THE INVENTION
[0005] It is therefore an object of this invention to provide
composite systems with integrated electrical subsystems.
[0006] It is a further object of this invention to provide, in one
embodiment, a notional antenna fully integrated with a composite
aircraft wing panel.
[0007] It is a further object of this invention to provide such an
integrated notional antenna which also includes a bus integrated
with composite aircraft structural members.
[0008] It is a further object of this invention to provide, in
composite structures, signal transmission pathways through the
thickness of the composite and running in the plane of the
composite.
[0009] It is a further object of this invention to provide a
functional replacement for a plated through hole in a printed
circuit board when materials and/or geometries prevent a plated
through hole from being formed.
[0010] The subject invention results from the realization that,
given a three dimensional composite system, electrical pathways in
one direction can be established by inserting conductive pins to
extend through the composite panel and an electrical pathway in the
direction of the plane of the panel can be affected by integrating
conductors into a ply of a composite component. The invention
results from the further realization that when plated through holes
or vias in a printed circuit board are not possible, conductive
pins may replace them as electrical pathways.
[0011] The subject invention, however, in other embodiments, need
not achieve all these objectives and the claims hereof should not
be limited to structures or methods capable of achieving these
objectives.
[0012] This invention features an electromechanical structure
including a core and a plurality of conductive pins through the
core. The pins are configured to form a signal distribution network
from a first side of the core to a second side of the core. In one
embodiment, there is an array of radiating elements on the first
side of the core each connected to one end of a pin, and a printed
circuit board on a second side of the core electrically connected
to the other ends of the pins forming a notional antenna subsystem.
In one configuration, the electromechanical structure further
includes a composite member which includes plies of fabric and
resin impregnating the plies of fabric and at least one ply
includes signal transmission elements integrated therewith and
connected between the printed circuit board and electronics for the
notional antenna system. The core may be a dielectric, and the
dielectric core may be air. In such an example, the dielectric core
will typically include a dielectric support mechanism which may be
a dielectric honeycomb structure, or a dielectric truss structure
for example. Such a dielectric truss structure may include a
network of dielectric pins forming the truss structure. The
dielectric core also may be a low density material, preferably
foam, or the dielectric core may be a polymer. In one example, the
structure includes a radome layer over the radiating elements,
which may be made of astroquartz. In one preferred embodiment, a
ground plane is disposed between the core and the printed circuit
board, and the ground plane may be a composite layer including
plies of conductive fibers impregnated with a resin, and the fibers
may be carbon. The structure may further include a structural layer
between the ground plane and the printed circuit board, and the
structural layer may include a foam sub-layer on a composite
sub-layer. The composite sub-layer may include fibers impregnated
with a resin, and the composite sub-layer fibers may be carbon.
Typically, the ground plane includes holes therethrough for
conductive pins. The conductive pins may be insulated and/or the
holes may provide clearance between the conductive pins and the
ground plane. Preferably, the pins are solid and made of a metal
alloy, which may include copper. In another configuration, the pins
include a composite core surrounded by metal coating. In a further
configuration, the pins include a central conductor surrounded by a
dielectric material surrounded by a coaxial shield conductor. In
another variation the pins may be tubular, and in one configuration
some pins may be configured to provide sidewall metallization
around a cavity of radiating element.
[0013] The radiating elements may be printed on the core. The pins
may be inserted through holes drilled in the core, or the pins may
first be inserted through the holes formed in the dielectric core
and the radiating elements then printed over the pins. The signal
transmission elements are preferably wires which may be woven into
the at least one ply of the composite member, and the wires may be
insulated. In one example, the core is a solid composite component
made of a number of plies of fabric impregnated with a resin.
[0014] This invention also features an electromechanical structure
including a low density dielectric core, an array of radiating
elements one side of the core, and a printed circuit board on an
opposing side of the core. There are a plurality of conductive pins
through the core and insulated therefrom. The pins are configured
to form a signal distribution network from the radiating elements
to the printed circuit board.
[0015] This invention further features a method of fabricating an
electromechanical structure, the method including inserting a
plurality of conductive pins through a core and configuring the
pins to form a signal distribution network from a first side of the
core to a second side of the core. In one embodiment there is an
array of radiating elements on the first side of the core each
connected to one end of a pin and a printed circuit board on a
second side of the core electrically connected to the other ends of
the pins forming a notional antenna subsystem. In one
configuration, the method further includes the addition of a
composite member, which itself includes plies of fabric and resin
impregnating the plies of fabric. At least one ply includes signal
transmission elements integrated therewith and connected between
the printed circuit board and electronics for the notional antenna
system. The core is typically a dielectric, and it may be air, in
which case the dielectric core will typically include a dielectric
support mechanism. The dielectric support mechanism may be a
dielectric honeycomb structure, or the dielectric support mechanism
may be a dielectric truss structure, which may include a network of
dielectric pins forming the truss structure. The dielectric core
may be a low density material, preferably foam, or the dielectric
core may be a honeycomb structure. In one example, the method
further includes disposing a radome layer over the radiating
elements, which may be made of astroquartz. A ground plane may be
disposed between the core and the printed circuit board, in which
the ground plane is a composite layer including plies of conductive
fibers impregnated with a resin, and the fibers are carbon. The
method may further include disposing a structural layer between the
ground plane and the printed circuit board, and the structural
layer may include a foam sub-layer on a composite sub-layer. The
composite sub-layer may include fibers impregnated with a resin,
and the composite sub-layer fibers may be carbon. The method may
further include drilling holes therethrough for the conductive
pins, and the conductive pins may be insulated. The holes may also
provide clearance between the conductive pins and the ground plane.
Preferably, the pins are solid and made of a metal alloy which may
include copper. In one variation, the pins include a composite core
surrounded by metal coating. In another variation, the pins include
a central conductor surrounded by a dielectric material surrounded
by a coaxial shield conductor. The pins may be tubular, and in one
variation, the pins may be configured to provide sidewall
metallization around a cavity of a radiating element.
[0016] The method may further include printing the radiating
elements on the core, and inserting the pins through holes drilled
in the core. In one variation, the pins may be first inserted
through the holes formed in the dielectric core and the radiating
elements then printed over the pins. The signal transmission
elements may be wires woven into the at least one ply of the
composite member, and the wires may be insulated. Also, the core
may be a solid composite component made of a number of plies of
fabric impregnated with a resin.
[0017] This invention also features a method of fabricating an
electromechanical structure, the method including inserting a
plurality of conductive pins through a low density dielectric core
and insulating the pins from the low density dielectric core and a
ground plane. The method further includes disposing an array of
radiating elements one side of the core, disposing a printed
circuit board on an opposing side of the core, and configuring the
pins to form a signal distribution network from the radiating
elements to the printed circuit board.
[0018] This invention further features an electromechanical
structure including a core, a plurality of conductive pins through
the core, the pins configured to form a signal distribution network
from a first side of the core to a printed circuit board on a
second side of the core. In one preferred embodiment, there is a
ground plane between the core and the printed circuit board, and
the ground plane is a thin layer between the core and the printed
circuit board. The thin layer may be copper, and the core is
typically a dielectric core. In one example, there is an array of
radiating elements on the first side of the core each connected to
one end of a pin, and the printed circuit board is electrically
connected to the other ends of the pins forming a notional antenna
subsystem. The notional antenna subsystem may be configured to be
affixed to an aircraft panel, in one example. The dielectric core
may be air, and in such a case the dielectric core will typically
include a dielectric support mechanism. The dielectric support
mechanism may be a dielectric honeycomb structure, or the
dielectric support mechanism may be a dielectric truss structure.
The truss structure may include a network of dielectric pins
forming the truss structure. The dielectric core may also be a low
density material, preferably foam. The dielectric core may also be
a polymer. There may be a radome layer over the radiating elements,
and it may be made of astroquartz. The ground plane may include
holes therethrough for the conductive pins. The conductive pins may
be insulated, and/or the holes may provide clearance between the
conductive pins and the ground plane. The pins may be solid and
made of a metal alloy including copper or the pins may include a
composite core surrounded by metal coating. In other examples, the
pins include a central conductor surrounded by a dielectric
material surrounded by a coaxial shield conductor, or the pins may
be tubular. Also, some of the pins may be configured to provide
sidewall metallization around a cavity of radiating element.
Radiating elements may be printed on the core and the pins inserted
through holes drilled in the core, or the pins may be first
inserted through the holes formed in the dielectric core and the
radiating elements are then printed over the pins.
[0019] This invention also features a method of fabricating an
electromechanical structure, the method including pre-drilling
pilot holes in a dielectric core, pre-forming pilot holes in a
ground plane, pre-drilling holes in a printed circuit board, and
inserting a plurality of conductive pins through each of the
printed circuit board, the ground plane, and the dielectric core to
bond together the dielectric core, ground plane and printed circuit
board.
[0020] This invention further features a method of fabricating an
electromechanical structure, the method comprising pre-drilling
pilot holes in a ground plane attached to a printed circuit board,
bonding the ground plane and printed circuit board to a dielectric
core, drilling holes through the printed circuit board and
dielectric core coinciding with the pre-drilled pilot holes in the
ground plane, and inserting a plurality of conductive pins through
each of the printed circuit board, the ground plane, and the
dielectric core.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Other objects, features and advantages will occur to those
skilled in the art from the following description of a preferred
embodiment and the accompanying drawings, in which:
[0022] FIG. 1 is highly schematic three-dimensional view showing an
example of a composite system with an integrated electrical
subsystem in accordance with the subject invention;
[0023] FIG. 2 is a schematic three-dimensional top view of a
fighter aircraft including a wing section with an integrated
antenna array in accordance with the subject invention;
[0024] FIG. 3 is a schematic three-dimensional cutaway side view
showing a portion of the wing of FIG. 2;
[0025] FIG. 4 is a schematic side cross-sectional view of the wing
structure shown in FIG. 3;
[0026] FIG. 5 is a highly schematic three-dimensional view of one
embodiment of a dielectric support mechanism for use with the
subject invention;
[0027] FIG. 6A-6B are highly schematic views of another embodiment
of a dielectric support mechanism for use with the subject
invention;
[0028] FIG. 7 is a highly schematic representation showing how
individual insulated wires can be woven with the fabric of a ply of
a composite structure in accordance with the subject invention;
[0029] FIG. 8 is a schematic three-dimensional cut-away view
showing one embodiment of a radar tile assembly for a notional
antenna integrated as part of a panel of the wing structure of FIG.
3;
[0030] FIG. 9A is a schematic cross-sectional view of an example of
one type of pin useful as a transmission element in accordance with
the subject invention;
[0031] FIG. 10A is a schematic cross-sectional view showing another
example of a transmission pin in accordance with the subject
invention;
[0032] FIG. 11A is a schematic cross-sectional view of still
another embodiment of a transmission pin in accordance with the
subject invention;
[0033] FIG. 12A is a schematic cross-sectional view of yet another
embodiment of a transmission pin in accordance with the subject
invention;
[0034] FIGS. 9B-12B are schematic views showing the pin examples of
FIGS. 9-12 insulated;
[0035] FIG. 13 is a schematic three-dimensional cut-away view
showing another embodiment of a radar tile assembly for a notional
antenna integrated as part of the top panel of the wing structure
shown in FIG. 3;
[0036] FIG. 14 is a three-dimensional cut-away view of a
multi-layer printed circuit board without plated through holes
shown as part of another form of a notional antenna in accordance
with the present invention;
[0037] FIG. 15 is a schematic three-dimensional front view showing
one example how transmission or feed pins are inserted into a foam
body in accordance with the subject invention;
[0038] FIG. 16 is a schematic three-dimensional front view showing
one example how radiator patches are deposited on the foam body of
FIG. 15 over the pins;
[0039] FIG. 17 is a schematic three-dimensional front view showing
one example of fabrication of a multi-layer printed circuit board
for power and signal re-distribution for the panel of the aircraft
wing structure shown in FIG. 3;
[0040] FIG. 18 is a schematic three-dimensional front view showing
one example how the flex circuit of FIG. 17 is bonded to the foam
panel of FIG. 16 in accordance with the subject invention;
[0041] FIG. 19 is a schematic view of one example of a fabrication
process in accordance with the present invention;
[0042] FIGS. 20-24 are schematic views of another example of a
fabrication process in accordance with the present invention;
[0043] FIG. 25 is a schematic three-dimensional side view of an
electromechanical tile test structure in accordance with the
subject invention;
[0044] FIG. 26 is a highly schematic three-dimensional front view
of an example of the dual function composite and electrical system
in accordance with the subject invention; and
[0045] FIG. 27 is a schematic top view of conductive pins
configured in one example for sidewall metallization around a
cavity of a radiating element in accordance with one embodiment of
the subject invention.
DISCLOSURE OF THE PREFERRED EMBODIMENT
[0046] Aside from the preferred embodiment or embodiments disclosed
below, this invention is capable of other embodiments and of being
practiced or being carried out in various ways. Thus, it is to be
understood that the invention is not limited in its application to
the details of construction and the arrangements of components set
forth in the following description or illustrated in the drawings.
If only one embodiment is described herein, the claims hereof are
not to be limited to that embodiment. Moreover, the claims hereof
are not to be read restrictively unless there is clear and
convincing evidence manifesting a certain exclusion, restriction,
or disclaimer.
[0047] FIG. 1 illustrates a simplified view of a three-dimensional
composite system 10 including composite members 12 and 14.
Composite member 12 typically includes face sheets 16 and 18
separated by core 20. Face sheets 16 and 18 may be fabricated from
plies of fabric impregnated with resin. Core 20 may be a
lightweight cellular material, e.g. foam, or air. Composite member
14 includes numerous plies of fabric impregnated with resin.
[0048] One goal of the subject invention is to route signals from
electronic subsystem A through composite system 10 to electronic
subsystem B. Conductive pin 24 is shown extending through the
thickness of composite member 12 to provide signal routing in one
direction through the thickness of the composite member and wire 26
is shown integrated with the fabric of one ply of composite member
14 to provide signal routing in another direction mainly in the
plane of composite member 14. By using multiple pins in composite
member 12 and multiple wires integrated with one or more plies of
the composite member 14, multiple electrical pathways and/or a bus
can be established between subsystems A and B.
[0049] In accordance with the present invention, aircraft 32, FIG.
2 includes an integrated notional antenna electrically
interconnected with an electronic subsystem within aircraft 32. The
integrated notional antenna can be located on any portion of a
mobile platform such as an aircraft, for example, on the panel of
an airplane fuselage or portion of a door. As shown, the integrated
notional antenna is included in wing portion or panel 30 of
aircraft 32.
[0050] Wing portion 30 is shown in more detail in FIGS. 3-4.
Composite lower wing surface 34 includes an integrated array of
radiating elements 36. Elements 36 may be rectangular, circular or
elliptical with dimensions on the order of 0.1 inches by 0.1 inches
up to several inches by several inches depending on the radar
operating frequency. The separation between the centers of elements
36 can be or the order of 0.25 inches to several feet.
[0051] Integrated wires 26 may be included in any suitable
structural member such as an aircraft fuselage, door, or portion of
a wing. In one preferred configuration, composite spar 38 includes
integrated wires 26 for connecting the antenna subsystem to its
associated electronics package and for providing support for the
aircraft wing panel. As shown more clearly in FIG. 4, the notional
antenna subsystem includes an array of radiating elements 36
separated from ground plane 40 by core 42 of low density or
lightweight cellular material, or air, serving as a standoff
dielectric. The dielectric may be any polymer, foam (open cell or
closed cell), or in the case where core 42 is air, structural
integrity is maintained by a dielectric support mechanism 11, FIGS.
5 and 6A-6B. One embodiment of such a dielectric support mechanism
11 is honeycomb structure 13, FIG. 5, which may be made up of
plastic, thermoplastic polymer, e.g., liquid crystal polymer or
LCP, Kevlar, aramid, or other known materials. In another example,
structural support can be provided by a dielectric support
mechanism 11 including a network of dielectric pins 15 configured
as truss structure 17, FIGS. 6A-6B. One example of such a structure
is discussed in U.S. Pat. No. 6,291,049 which is incorporated
herein by reference. Dielectric pins 15 are typically
non-conductive material such as ceramic, glass, polymer or other
known material. The size, number, and angles of dielectric pins 15
may be varied depending on a particular desired application.
[0052] In one preferred embodiment, the radiating elements 36, FIG.
4 are separated from ground plane 40 by dielectric open cell foam
core 42 made of polyetherimide or polymethacrylimide with a
thickness in the range between approximately several thousandths of
an inch to several inches depending a particular application or
design operating frequency. Conductive pins 24 extend through the
core and each one is connected on one end to a radiating element
36. The other ends of the pins are electrically connected to
printed circuit board 44 which is connected as shown at 46 to wires
26 integrated (e.g., woven, knitted or braided) with the fabric of
one ply of composite spar 38. Cover or radome layer 48 is shown
over radiating elements 36, typically to decrease aerodynamic
drawbacks and to protect radiating elements 36. Layer 48 is
preferably made of astroquartz or glass, but may be made of any
material which is effectively transparent at appropriate
frequencies of radar operations. In the case of placement on an
airplane wing, such material will typically possess load-bearing
characteristics to withstand environmental stresses encountered
along the wing of an aircraft. Typically, ground plane 40 is a
composite structure including plies of conductive (e.g., carbon)
fiber impregnated with a resin such as Cytec 977-3 or Hexel M73.
Optional structural layer 50 includes structural foam sub-layer 52
and composite sub-layer 54.
[0053] FIG. 7 shows one internal ply of composite spar 38, FIG. 4
where insulated wires or cables 26 are interwoven, with fabric
threads 56. In one example, spar 38 includes a textile impregnated
with a resin. See also U.S. Pat. No. 6,727,197 incorporated herein
by this reference. Alternatively, wires 26 may be woven or knitted
with fabric threads 56.
[0054] FIG. 8 shows in more detail multilayer printed circuit board
44 with back side transmit and receive components 60 and back side
redistribution layers 62. Foam layer 42 forms a dielectric
standoff. Sub-layer 52 in combination with ground plane 40, itself
typically including carbon fibers, and carbon fiber composite
sub-layer 54, provide mechanical strength and stiffness and provide
a suitable load-bearing structure where lightweight, high
structural strength and rigidity are important considerations.
Similarly to core 42, sub-layer 52 may include a honeycomb
structure, truss structure, or low density material, and like core
42, is preferably foam in one embodiment. Sub-layer 52 may have a
thickness in the range of between approximately 0.25 inches and 2
inches, and sub-layer 54 together with ground plane 40 may have a
thickness in the range of between approximately 0.06 inches and
0.10 inches. In one preferred embodiment, foam layer 42 is
approximately 0.10 inches thick, sub-layer 52 is approximately 0.25
inches thick, and sub-layer 54 together with ground plane 40 is
approximately 0.10 inches thick. Pins 24 provide feeds to radiating
elements 36 from a metallurgical connection with a backside pad as
shown at 63. Such a high aspect ratio hybrid structure is not
generally achievable with conventional printed circuit board
manufacturing techniques.
[0055] In one example, pin 24, FIG. 9A may be solid metal alloy
made of copper and beryllium and be between approximately 0.005
inches and 0.062 inches in diameter. There are typically 1-2 pins
per radiating element.
[0056] In another embodiment, pin 24', FIG. 10A includes composite
core 70 surrounded by metal coating 72 such as nickel/gold. In
still another embodiment, coaxial pin 24'', FIG. 11 A includes
central conductor 74 surrounded by dielectric 76 itself surrounded
by a coaxial shield 78 made of conductive material to isolate
central conductor 74 from any external electrical radiation.
Alternatively, pin 24''', FIG. 12A is tubular and made of metal
alloy such as copper and beryllium. In any configuration, pins
24-24''' may be insulated. Pilot holes drilled in circuit board 44,
FIG. 8 enable small diameter pins to be inserted to minimize use of
circuit board area for pin interconnects. The pilot holes can be
undersized for a slight press fit with the individual pins.
Although pins 24 are shown herein as extending vertically, this is
not a necessary limitation of the invention, and pins 24 may be
oriented at an angle as desired for a particular application. Also,
although pins 24 are preferably electrical conductors, this is not
a limitation of the invention. In one configuration, the pins may
be optical fibers for connecting the systems.
[0057] In the embodiment of FIG. 8, ground plane 40 abuts pins 24,
and therefore pins 24 in multilayer printed circuit board 44 are
preferably insulated to prevent electrical contact with ground
plane 40. In one example, pins 24 are isolated from the ground
plane by non-conductive insulating material 77. Insulation 77 may
surround pin types 24, 24', 24'', and 24''' as desired for a
particular application as shown in FIGS. 9B-12B. Insulation 77 may
be polymer, glass, ceramic, Kevlar, fiberglass, or any other
non-conductive material.
[0058] In another embodiment, multilayer printed circuit board 44,
FIG. 13 does not include structural layer 50, FIG. 4, however,
ground plane 40 including plies of carbon fiber impregnated with
resin provides structural support. Since ground plane 40 abuts pins
24, insulated pins 24 are preferred.
[0059] In a further embodiment, ground plane 40', FIG. 14 of
multilayer printed circuit board 44' forms a thin top layer over
the printed circuit board 61 including backside redistribution
layers 62. In one example, ground plane 40' is a copper metal layer
typically between 0.0003 inches and 0.003 inches thick. Although
minimal to no structural support is provided, due to its light and
flexible nature, in one example multilayer printed circuit board
44' may serve as another type of notional antenna which can be
affixed to an aircraft by attaching or hanging it rather than
forming an integral portion of the aircraft structure. In a
preferred configuration, ground plane 40' includes clearance holes
68 therethrough for conductive pins 24 so the pins do not contact
the ground plane. In this case, pins 24 may be insulated or
non-insulated as desired.
[0060] Accordingly, the subject invention provides composite
systems with integrated electrical subsystems, in one example
notional antennas, and in various embodiments, further provides an
improved alternative to plated through holes where material types
or other parameters such as high aspect ratio prohibit the use of
conventional boards.
[0061] In one embodiment, fabrication begins by inserting feed pins
24 in foam panel 42, FIG. 15. The pins can be inserted manually
with or without pilot holes drilled in foam panel 42, inserted
using an ultrasonic horn, and/or inserted using numerical control
processes. Next, radiator elements 36 are direct metal deposited on
foam panel 42, FIG. 16. A protective layer (not shown) such as LCP,
epoxy glass, or the like or a bonding film or layer or
metamaterials may be used to bond the elements 36 to panel 42. The
radiator elements make metallurgical contact with the pins 24
previously inserted in foam panel 42. Alternatively, a direct
printing technique can be used to create a radiator element
pattern, or patched radiator elements could be formed on a flex
circuit film bonded to foam panel 42.
[0062] Next, the multilayer printed circuit board is fabricated as
shown in FIG. 17 to include copper ground plane 40, clearance holes
68, power and distribution circuitry as shown at 90 all on a
multilayer flex circuit board. The multilayer flex circuit board
may include a flexible substrate such as polyimide, LCP, or foam.
This multilayer printed circuit board provides power and signal
redistribution and backside component attachment for MMICs and the
like, and one example of the resultant multi-layer printed circuit
board is board 44', FIG. 14, where pins 24 are uninsulated.
[0063] Thus, this flex circuit is bonded to the foam panel as shown
in FIG. 18. Solder reflow techniques are used to electrically
interconnect the radiator feeds provided by pins 24 to the flex
circuit. The solder is reflowed to complete the metallurgical
connection of the pad to pin on the back side. In one variation, a
conductive polymer such as conductive epoxy could be used in place
of solder.
[0064] In another embodiment, fabrication begins by pre-drilling
pilot holes 71, FIG. 19 in foam core 42 and pre-drilling pilot
holes 73 in printed circuit board 61 which typically includes
redistribution portion 62. Pilot holes 75 are formed in ground
plane 40 and sub-layers 52 and 54 typically by using an ultrasonic
horn using known ultrasonic techniques. Next, feed pins 24 are
inserted through printed circuit board 61, sub-layers 52 and 54,
ground plane 40, and core 42 from backside 67, thus bonding the
various layers together and forming an electromechanical structure,
i.e. a multi-layer printed circuit board, and in one example, the
resultant multi-layer circuit board may be board 44, FIG. 8, after
inclusion of metallurgical elements, antenna elements, and the like
as desired for a particular application.
[0065] A further embodiment is shown in FIGS. 21-24, where
fabrication begins by pre-drilling pilot holes 80, FIG. 21 in
ground plane 40 which is a thin top layer over printed circuit
board 61 including redistribution portion 62. Next, foam core 42 is
attached to ground plane 40 and printed circuit board 61 and ground
plane 40 are drilled, FIG. 22, and pins 24 are then inserted
through each of the printed circuit board 61, the ground plane 40,
and the foam core 42, FIG. 23. Next, metallurgical connections 63,
FIG. 24 can be formed as shown, and antenna elements 36 may be
direct deposited or printed on core 42 as discussed above. In each
variation, the resulting electromechanical structure is capable of
being used in place of printed circuit boards with plated through
holes for particular desired applications as discussed above.
[0066] FIG. 25 shows one electromechanical test tile structure 100
manufactured in accordance with this invention where electrical
pathways are formed between path 102 on each face plate 104a and
104b on foam core 106. In this way, as shown in FIG. 26, a wide
variety of electrical interconnections could be formed to provide
signal transmission between point 110 on face sheet 104a to point
112 through core 106 (e.g., a foam or air core) via transversely
extending pins 24a and 24b. Conventional plated through hole
technology cannot be used with most foam core composites and thus
pins 24 provide a suitable replacement to provide pathways through
the structure. And then, to provide electrical pathways in the
planar direction of a composite structure, conductors are
integrated with the fabric of at least one ply thereof, e.g.,
conductor 26 interwoven with the fabric of a ply of composite face
sheet 104a. More than one ply may include conductive wires woven,
knitted, or braided with the fabric thereof, and the internal or
external plies could be chosen as desired to include pathways
through the structure. Pins can be inserted through the thickness
of a core, as discussed above and in U.S. Pat. No. 6,291,049 which
is incorporated herein by this reference, to reinforce the
structure, to prevent delamination of the individual plies with
respect to each other, and to provide electrical pathways through
the structure. In such an example, foam core 106, FIG. 25 could be
eliminated and there would simply be a number of composite fabric
plies between face plate 104a and face plate 104b. Thus, aircraft
wing notational antenna subsystem referred to in FIGS. 2-24 above
are but only a few examples of the wide variety of uses of the
innovative technology of the subject invention. Other uses include,
but are not limited to, thermal conductivity and management, where
pins serve as thermal shunts to transfer heat, or pins 24 may be
inserted through the thickness of the composite structure to
provide sidewall metallization around the cavity of a radiating
element 36, as shown in FIG. 27.
[0067] Although specific features of the invention are shown in
some drawings and not in others, this is for convenience only as
each feature may be combined with any or all of the other features
in accordance with the invention. The words "including",
"comprising", "having", and "with" as used herein are to be
interpreted broadly and comprehensively and are not limited to any
physical interconnection. Moreover, any embodiments disclosed in
the subject application are not to be taken as the only possible
embodiments. Other embodiments will occur to those skilled in the
art and are within the following claims.
[0068] In addition, any amendment presented during the prosecution
of the patent application for this patent is not a disclaimer of
any claim element presented in the application as filed: those
skilled in the art cannot reasonably be expected to draft a claim
that would literally encompass all possible equivalents, many
equivalents will be unforeseeable at the time of the amendment and
are beyond a fair interpretation of what is to be surrendered (if
anything), the rationale underlying the amendment may bear no more
than a tangential relation to many equivalents, and/or there are
many other reasons the applicant can not be expected to describe
certain insubstantial substitutes for any claim element
amended.
* * * * *