Electromechanical structure and method of making same
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.
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 INVENTIONThis 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 INVENTIONComposite 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.
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 INVENTIONIt is therefore an object of this invention to provide composite systems with integrated electrical subsystems.
It is a further object of this invention to provide, in one embodiment, a notional antenna fully integrated with a composite aircraft wing panel.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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 DRAWINGSOther 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:
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.
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.
In accordance with the present invention, aircraft 32,
Wing portion 30 is shown in more detail in
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
In one preferred embodiment, the radiating elements 36,
In one example, pin 24,
In another embodiment, pin 24′,
In the embodiment of
In another embodiment, multilayer printed circuit board 44,
In a further embodiment, ground plane 40′,
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.
In one embodiment, fabrication begins by inserting feed pins 24 in foam panel 42,
Next, the multilayer printed circuit board is fabricated as shown in
Thus, this flex circuit is bonded to the foam panel as shown in
In another embodiment, fabrication begins by pre-drilling pilot holes 71,
A further embodiment is shown in
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.
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.
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.
Type: Application
Filed: Jul 28, 2006
Publication Date: Feb 8, 2007
Inventors: Brian Farrell (Quincy, MA), John Gannon (Sudbury, MA), Thomas Campbell (Concord, MA), Pat Coppola (Bedford, MA), Sean O'Reilly (Brighton, MA), Joseph Burke (Atkinson, NH)
Application Number: 11/495,789
International Classification: F21S 6/00 (20060101);