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US 2003/0116856 A1Published application
Resistive vias for controlling impedance and terminating I/O signals at the package level
AssigneeSun Microsystems, Inc.
InventorsNayon Tomsio, Avi Liebermensch
Life of this patent
Estimating the term…
Abstract
A circuit package and a method of forming the same that facilitates control of the impedance of a driving circuit employing resistive vias formed into a dielectric substrate.
Claims20
A circuit package, comprising:
- a dielectric substrate having a first surface and a second surface, disposed opposite to said first surface, and a via extending therebetween, with a first conductor disposed on said surface and extending from said via, and a second conductor disposed on said second surface and extending from said via, with said via placing said first and second conductors in electrical communication;
- and
- a driver circuit mounted to said substrate and including an input and an output, with said output being in electrical communication with said first conductor and having an output resistive component associated therewith, with said via having a resistive fill disposed therein, defining a via resistance connected between said first and second conductors, said output having an output impedance being defined by said output resistive component and said via resistance.
A circuit, comprising:
- a dielectric substrate having a first surface and a second surface, disposed opposite to said first surface and a plurality of vias extending therebetween, with first and second conductors disposed on said first surface and a third conductor disposed on said second surface, with said first and third conductors and extending from a first of said plurality of vias and said second and third conductors extending from a second of said plurality of vias;
- a driver circuit mounted to said substrate and including an output having an output resistive component associated therewith, and an input having an input resistive component associated therewith, with said output being in electrical communication with said first conductor and said input being in electrical communication with said second conductor, with said first via having a resistive fill disposed therein defining a first via resistance connected between said first and third conductors and said second via having said resistive fill disposed therein defining a second via resistance connected between said second and third conductors said output having an output impedance associated therewith defined by said output resistive component and said first via resistance first via resistance, having a magnitude that is at least twice a magnitude of said output resistive component, with said input having an input impedance associated therewith defined by said input resistive component and said second via resistance, with said second via resistance having a magnitude that is at least twice a magnitude of said input resistive component.
A method of establishing an impedance of a circuit package, said method comprising:
- attaching said circuit driver to a dielectric substrate having a first surface and a second surface, disposed opposite to said first surface and a via extending therebetween, with a first conductor disposed on said surface and extending from said via and a second conductor disposed on said second surface and extending from said via, with said via placing said first and second conductors in electrical communication, with said driver circuit including an input and an output, with said output being in electrical communication with said first conductor and having an output impedance associated therewith that includes an output resistive component and an output reactance component;
- and
- filling said via with a resistive fill to define a resistance connected between said first and second conductors, with said resistance being of sufficient magnitude to define dominant component of said output impedance.
Dependencies are inferred from the claim text.