Stair step printed circuit board structures for high speed signal transmissions
View Patent ↗Disclosed are stair stepped PCB structures which provide high performance, direct path, via-less interconnections between various elements of an electronic interconnection structure including, among others, IC packages and connectors.
1. An electrical assembly with a circuit board and at least one integrated circuit package coupled to the circuit board, the electrical assembly comprising:
a first dielectric layer;
a second dielectric layer with a first surface and a second surface, the first surface disposed adjacent the first dielectric layer, the second dielectric layer having first and second apertures therein to expose respective first and second regions of the first dielectric layer;
a first plurality of signal conductors disposed between the first and second dielectric layers and extending from the exposed first region of the first dielectric layer to the exposed second region of the first dielectric layer;
a second plurality of signal conductors disposed on the second surface of the second dielectric layer and extending from a periphery of the first aperture to a periphery of the second aperture, the second plurality of signal conductors being electrically isolated from the first plurality of signal conductors; and
a first integrated circuit package disposed within the first aperture.
2. The electrical assembly of claim 1 wherein the first integrated circuit device includes an electrical contact electrically coupled with a signal conductor from among the first plurality of signal conductors.
3. The electrical assembly of claim 2 wherein at least one of the first and second apertures is polygon.
4. The electrical assembly of claim 2 further comprising a second integrated circuit device disposed in the second aperture.
5. The electrical assembly of claim 2 wherein the first integrated circuit device comprises a second contact electrically coupled with an electrical conductor from among the second plurality of signal conductors.
6. The electrical assembly of claim 1 wherein the first dielectric layer further comprises a third aperture disposed substantially concentric with the first aperture of the second dielectric layer.
7. The electrical assembly of claim 6 wherein the third aperture is smaller than the first aperture such that the exposed first region of the first dielectric layer has an area defined by the area of the first aperture minus the area of the third aperture.
8. The electrical assembly of claim 6 further comprising a multi-layer substrate having a third plurality of signal conductors disposed therein, and wherein the first dielectric layer is disposed on a first surface of the multi-layer substrate.
9. The electrical assembly of claim 8 wherein the third plurality of signal conductors comprise a plurality of conductive vias within an area bounded by the first aperture and the third aperture.
10. The electrical assembly of claim 7 further comprising:
a third dielectric layer having opposite first and second surfaces, and wherein the first dielectric layer is disposed on the first surface of the third dielectric layer; and
a third plurality of signal conductors disposed on the first surface of the third dielectric layer, each of the third plurality of signal conductors having a respective first end within an area bounded by the third aperture.
11. The electrical assembly of claim 10 further comprising:
a fourth aperture formed within the third dielectric layer;
a fourth dielectric layer having a first surface facing the second surface of the third dielectric layer; and
a fourth plurality of signal conductors disposed on the first surface of the fourth dielectric and having respective first ends disposed within an area of the fourth aperture.
12. An electronic interconnection assembly comprising:
a plurality of electrically separate signal conductors disposed on a plurality of layers of a stair stepped printed circuit board (PCB), including a first signal conductor disposed on a first layer and having first and second ends extending into respective first and second stair stepped regions to form first and second stair stepped contacts, and a second signal conductor disposed on a second layer having first and second ends respectively extending into the first and second stair step regions to form third and fourth stair stepped contacts;
a first integrated circuit package having first and second terminals respectively coupled with the first and third contacts; and
an electronic component having third and fourth terminals respectively coupled with the second and fourth contacts.
13. The electronic interconnection assembly of claim 12 wherein the first and second terminals are stair stepped contacts which are disposed to mate with the first and third stair stepped contacts on the PCB.
14. The electronic interconnection assembly of claim 12 wherein the first integrated and second terminals are coupled with the stair stepped contacts on the PCB by flexible couplings.
15. The electronic interconnection assembly of claim 12 wherein the electronic components comprises a second integrated circuit package.
16. The electronic interconnection assembly of claim 12 wherein the electronic component comprises an electronic connector.
17. An electronic connector comprising:
a first plurality of terminations configured for pin-in-hole connection to a printed circuit board (PCB); and
a second plurality of terminations configured for stair stepped connection to the PCB, wherein the first plurality of terminations comprise conductive pins that extend from a first surface of the electronic connector for insertion into holes in the circuit board (PCB); and wherein the second plurality of terminations comprise conductive fingers that extend from a second surface of the electronic connector to contacts disposed at different elevations on the PCB.
18. A method of fabricating an electrical assembly, the method comprising:
disposing a first plurality of signal conductors on a surface of a first dielectric layer, the first plurality of signal conductors extending from a first region of the first dielectric layer to a second region of the first dielectric layer;
coupling a first surface of a second dielectric layer to the first dielectric layer over the first plurality of signal conductors, the second dielectric layer having first and second apertures therein the expose the first plurality of signal conductors at the first and second regions of the first dielectric layer;
disposing a second plurality of signal conductors on a second surface of the second dielectric layer, the second plurality of signal conductors extending from the first aperture to the second aperture;
coupling at least part of an IC package within the first aperture, wherein the first plurality of signal conductors are not electrically coupled with the second plurality of signal conductors;
electrically coupling first and second IC terminals of the IC package to corresponding first and second signal conductors among the first plurality of signal conductors; and
electrically coupling third and fourth IC terminals of the IC package to corresponding third and fourth signal conductors among the second plurality of signal conductors.
19. The electrical assembly of claim 3 wherein at least one of the first and second apertures is a rectangular polygon.