Patent ID: 7443265

Claim:
A method for impedance matching between differential vias and associated transmission lines, the method comprising the steps of: formulating an equation that uses a relationship of a characteristic impedance of the differential vias, a space between the differential vias, and a radius of the differential vias; calculating a characteristic impedance of the differential transmission lines as a desired impedance of the characteristic impedance of the differential vias; acquiring a relationship between the space and the radius according to the desired impedance and the equation; and determining the space and the radius according to the relationship between the space and the radius; wherein the equation is: Z = cos ⁢ ⁢ h - 1 ⁡ ( d / 2 ⁢ r ) π ⁢ u e Z is the characteristic impedance of the differential vias, u is a magnetic permeability of each of the differential vias, e is a dielectric constant, d is the distance between the differential vias, and r is the radius of the differential vias.