Flexible microstrip signal and power bus cable
A multi-layered, flat, flexible cable capable of transmitting both power and multiple control signals to the components of a network is disclosed. The cable provides all connections on its top surface using a via-less design that does not reduce the cross-sectional area of power and ground buses within the cable. This effect is achieved through the use of folded conducting tabs appearing at periodic intervals along one of the power and ground conducting layers, which are folded over onto the top of the cable for electrical connection thereto.
1. A flat cable, comprising:
(a) a first power conducting layer, wherein said first power conducting layer comprises a first power conductor, and the width of said first power conductor is more than half of the width of the cable;
(b) a second power conducting layer beneath said first power conducting layer, wherein said second power conducting layer comprises a second power conductor, and the width of said second power conductor is more than half of the width of the cable, and wherein said second power conductor further comprises a conducting tab folded around said first power conducting layer forming an electrical connecting pad over said first power conducting layer on a side of said first power conducting layer opposite said second power conducting layer;
(c) a first signal conductor layer above said first power conducting layer; and
(d) a top film layer above said first signal conductor layer, wherein said top film layer comprises openings for electrical connection to said signal conductor and said first and second power conducting layers.
2. The flat cable of claim 1 , further comprising a dielectric layer between said first signal conductor layer and said first and second power conducting layers.
3. The flat cable of claim 2 , further comprising a bottom film layer beneath said second power conducting layer.
4. The flat cable of claim 1 , further comprising a second signal conductor layer between said first signal conductor layer and said dielectric layer.
5. The flat cable of claim 1 , wherein said first signal conductor layer comprises a plurality of conducting strips.
6. The flat cable of claim 1 , wherein said first signal conductor layer comprises a first signal conductor insulating film and a conducting strip.
7. The flat cable of claim 6 , wherein said conducting strip is located at or near the edge of said first signal conductor layer.
8. The flat cable of claim 7 , further comprising a first signal conductor pad electrically connected to said first signal conducting strip.
9. The flat cable of claim 8 , wherein said first signal conductor pad extends laterally inwardly from said first signal conducting strip across the surface of said first signal conductor insulating film.
10. The flat cable of claim 2 , further comprising a locking tab extending from the edge of said cable.
11. The flat cable of claim 1 , wherein said first power conducting layer further comprises a first power layer insulating film bonded to said first power conductor and located between said first power conductor and said second power conductor.
12. The flat cable of claim 11 , wherein said second power conducting layer further comprises a second power layer insulating film bonded to said second power conductor and located between said first power layer insulating film and said second power conductor.
13. A flat cable, comprising:
(a) a signal layer;
(b) a power layer comprising one of a power conductor and a ground conductor, said power layer being at least substantially as wide as the cable along its length;
(c) a bus layer comprising a bus conductor at least substantially as wide as the cable along its length;
(d) a dielectric layer between said signal layer and said power and bus layers;
wherein one of said ground and power conductors further comprises a conducting tab extending outwardly from said one of said ground and power conductors;
wherein said tab bends over the side of the other of said ground and power conductors opposite said one of said ground and power conductors; and
wherein a top film comprises openings providing electrical communicative access to said signal layer, said tab, and said one of said power and bus conductors that does not comprise said tab.
14. The flat cable of claim 13 , wherein said tab is bent over upon the cable such that the width of said cable at the widest point of said cable is not substantially greater than the width of said cable at its narrowest point.
15. The flat cable of claim 13 , further comprising a top film that covers said signal layer and said tab in a continuous sheet.