US-20260129755-A1 - IMPEDANCE MATCHED VIA CONNECTIONS IN A PRINTED CIRCUIT BOARD

US20260129755A1US 20260129755 A1US20260129755 A1US 20260129755A1US-20260129755-A1

Abstract

Vertical launch impedance matched through-hole vias to ensure proper impedance matching is maintained after a printed circuit board connector is attached to a printed circuit board. A conductive via having a center aperture and a via body having a slot adjacent either the via top surface and/or via bottom surface, and a dielectric component insertable within the via center aperture, and having a slot aligned with the conductive via body slot. The dielectric component having a center aperture with a conductive member in electrical communication with a PCB signal trace without contact to the conductive via. A printed circuit board connector having a center signal pin with a slotted dielectric component attached thereto, or a slotted dielectric component in conjunction with a slotted, conductive via body attached thereto.

Inventors

Sri Satya Parthiva Sumanam
Salvatore J. Gullotta, SR.

Assignees

THE PHOENIX COMPANY OF CHICAGO, INC.

Dates

Publication Date: 20260507
Application Date: 20251027

Claims (20)

1 . A printed circuit board connector having a bottom surface for connection to a printed circuit board, said connector comprising: a connector center conductor for transmitting an electrical signal; a dielectric component having a body defining a dielectric component inside wall, an outside wall, a top surface, and a bottom surface, said dielectric component body including a center through-hole, wherein said connector center conductor is inserted within said dielectric component body center aperture or through-hole, said dielectric component body including an aperture or slot adjacent either said dielectric component top surface or bottom surface or both.
2 . The printed circuit board connector of claim 1 wherein said dielectric component body includes an aperture or slot adjacent either said dielectric component top surface or bottom surface or both.
3 . The printed circuit board connector of claim 1 including a conductive via body defining an inside wall, an outside wall, a top surface, and a bottom surface, wherein the inside wall forms a via through-hole.
4 . The printed circuit board connector of claim 1 including a conductive via body defining an inside wall, an outside wall, a top surface, and a bottom surface, wherein the inside wall forms a via through-hole, wherein said via body includes an aperture or slot adjacent either the via body top surface or via body bottom surface or both, such that said dielectric component body is situated within said via body center through-hole, and wherein said via body aperture or slot is aligned with said dielectric component aperture or slot when said dielectric component is inserted within said via center through-hole.
5 . The printed circuit board connector of claim 1 including a plurality of prongs extending below said printed circuit board connector bottom surface for attachment to the printed circuit board, said plurality of prongs forming a mechanical support for said printed circuit board connector.
6 . The printed circuit board connector of claim 5 wherein said plurality of prongs are in electrical communication with said ground or zero potential contact or line of said printed circuit board, and/or in electrical communication with at least one via body in said printed circuit board.
7 . A printed circuit board (PCB) connector assembly having a plurality of PCB connectors, each having a bottom portion for connection to a printed circuit board, at least one of said plurality of PCB connectors comprising: a connector center conductor for transmitting an electrical signal; a dielectric component having a body defining a dielectric component inside wall, an outside wall, a top surface, and a bottom surface, said dielectric component body including a center through-hole, wherein said connector center conductor is located within said dielectric component body center aperture or through-hole.
8 . The printed circuit board connector assembly of claim 7 wherein said dielectric component body includes an aperture or slot adjacent either said dielectric component top surface or bottom surface or both.
9 . The printed circuit board connector assembly of claim 7 including a conductive via body defining an inside wall, an outside wall, a top surface, and a bottom surface, wherein the inside wall forms a via through-hole.
10 . The printed circuit board connector assembly of claim 8 including a conductive via body defining an inside wall, an outside wall, a top surface, and a bottom surface, wherein the inside wall forms a via through-hole, wherein said via body includes an aperture or slot adjacent either the via body top surface or via body bottom surface or both, such that said dielectric component body is situated within said via body center through-hole, and wherein said via body aperture or slot is aligned with said dielectric component aperture or slot when said dielectric component is inserted within said via center through-hole.
11 . The printed circuit board connector assembly of claim 7 wherein at least one of said plurality of PCB connectors includes a PkZ® connector.
12 . The printed circuit board connector assembly of claim 7 wherein said plurality of PCB connectors are in the form of a square array, rectangular array, circular array, or polygon array.
13 . The printed circuit board connector assembly of claim 7 wherein a footprint of said PCB connector assembly is in the form of a square, rectangle, circle, or polygon shape.
14 . A printed circuit board connection assembly for conducting an electrical signal between a conductive strip of a printed circuit board and a printed circuit board connector, said assembly comprising: a printed circuit board (PCB) having a top surface, a bottom surface, and an interior therebetween, wherein said PCB includes a signal trace and/or a ground trace; a via having a body defining an inside wall, an outside wall, a top surface, and a bottom surface, wherein the via body inside wall forms a via body center through-hole, and wherein said via body includes an aperture or slot adjacent either the via body top surface or via body bottom surface or both, and wherein at least a portion of said via body is electrically conductive; and a dielectric component having a body defining an inside wall, an outside wall, a top surface, and a bottom surface, said dielectric component body sized for placement within said via body center through-hole, said dielectric component body including a center through-hole coaxial with said via body center through-hole, said dielectric component center through-hole supporting a conductive member, wherein said dielectric component body includes an aperture or slot adjacent either said dielectric component top surface or bottom surface or both, and wherein said via body aperture or slot is aligned with said dielectric component aperture or slot when said dielectric component is placed within said via body center aperture; a conductive trace and/or solder bridge formed on or within said PCB and traversing through said dielectric component aperture or slot and said via body aperture or slot to said dielectric component center through-hole without making contact with said via body, and in electrical communication with said dielectric component center through-hole conductive member.
15 . The printed circuit board connection assembly of claim 14 including: a printed circuit board connector having a bottom surface, a center conductor for carrying an electrical signal line, and an outer conductor carrying a ground line, wherein said signal line is in electrical communication with said dielectric component center through-hole conductive member.
16 . The printed circuit board connection assembly of claim 15 wherein said printed circuit board connector center conductor forms a contact pin or socket that extends beyond said printed circuit board connector bottom surface.
17 . The printed circuit board connection assembly of claim 16 wherein said printed circuit board connector center conductor is insertable within said dielectric component through-hole upon connection to said printed circuit board.
18 . The printed circuit board connection assembly of claim 15 wherein said dielectric component center through-hole conductive member extends through said dielectric from said dielectric top surface to said dielectric bottom surface.
19 . The printed circuit board connection assembly of claim 16 wherein said dielectric component conductive member includes a pin socket that is approximately flush with or below said dielectric component body top surface, and receives said printed circuit board connector center conductor contact pin.
20 . The printed circuit board connection assembly of claim 15 wherein said printed circuit board connector center conductor forms a pin socket that is approximately flush with said printed circuit board connector bottom surface.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to vias in printed circuit boards for electrically coupling electrical signals between conductive layers of the printed circuit boards. More specifically, the present invention relates to vertical launch impedance matched vias, and designs thereof to ensure proper impedance matching is maintained after a component is attached to a printed circuit board. 2. Description of Related Art Vias play a role as conductors connecting traces across different layers of a multi-layer PCB (Printed Circuit Board). Vias can be used in various applications. In one such application, an electrical signal must propagate or transition from a first conductive layer through a via to one or more other conductive layers in the PCB. An electrical signal transitioning through a via must have a low magnitude of reflection or low return loss to minimize errors in the signal. Due to the intrinsic geometrical difference between a via and its connected traces, there exists impedance mismatch at the via transition. As circuit switching speed dramatically increases into the multi-Gbps range, and the physical size of the circuit continues to shrink, this via impedance mismatch poses a serious problem. In the case of low frequency signals, vias generally have a minimal effect on signal transmission. However, as frequency rises and the signal rising edge becomes steep (e.g., on the order of 1 nanosecond), vias may not be regarded solely as a function of electrical connection; rather, influence of vias on signal integrity has to be carefully considered. Vias behave as breakpoints with discontinuous impedance introduced in transmission line propagation causing signal reflections. Moreover, as the frequency increases, the electrical length of a via impedance mismatching section becomes longer in relation to the signal and poses a more serious problem at higher frequency ranges. An impedance discontinuity at the junction of a via and an interconnect line creates signal reflections and contributes to the loss of the signal. Thus, it is necessary for via construction to consider and accommodate impedance matching to address potential signal degradation. Impedance matching is designing source and load impedances to minimize signal reflection or maximize power transfer. These reflections cause destructive interference, leading to peaks and valleys in the signal quality. In DC circuits, the source and load should be equal. In AC circuits, the source should either equal the load or the complex conjugate of the load, depending on the goal. Impedance matching challenges RF and microwave circuit design because the window for error should decrease as the frequency increases. High speed digital circuits require very stable controlled impedances because of the impact on bit error rate and the potential for pulse distortion, reflection, and electromagnetic interference. FIG. 1 depicts a typical electrical schematic of an impedance matching network having impedance Z in electrical communication with a source impedance, Zs, and a load impedance, ZL. Impedance matching is important to obtain a desirable loss response (return and insertion). FIG. 2 depicts the different types of via placements that may be established within a printed circuit board utilizing the via design of the present invention. In this illustrative example, shown are through-hole via 10, blind via 12, buried via 16, staggered vias 14 (combination of 12 and 16), which may be microvias, and a stacked, buried via 18. The different embodiments of the slotted bodies and slotted dielectric components of the present invention can be situated in any number of the via locations presented in FIG. 2. FIG. 3 depicts an isometric view of an End Launch Connection 20, the current state of the art for matching the impedance of a component to a PCB for high frequency performance. Component 22 is typically mounted on the edge of the PCB 24 with ground legs 26 extended onto the PCB 24, which typically act as ground (or zero potential) points of contact. A center signal contact extension 28 traverses onto the PCB signal trace 30 portion of the PCB. The center contact signal extension 28 and grounded legs 26 are designed with the PCB ground and PCB signal trace 30 to achieve matched impedance enabling high frequency performance. This design acts in a manner similar to a coaxial connection scheme. The PC board separates the signal line 30 from the ground legs 26. The connection depicted in FIG. 3 (end launch) limits the connector density (number of connectors) available on a board. Essentially, PCB edge real estate is limited, thus limiting the number of end launch connections. In order to make electrical connection for this type of connector, soldering is performed on top of the center and ground contact extensions. Ultimately, this style of connector design provides for a weaker connection bond to the PCB. A second config