Patent ID: 6762913
Filing Date: 2004-07-13
Classification: G11B,H05K

Abstract:
A method of adjusting the common mode impedance of printed circuit electrical traces on a head suspension assembly of the type having a load beam with a conductive layer separate from a layer containing the traces and forming a backed area for the traces and having at least one aperture in the conductive layer of the load beam, the aperture forming an unbacked area for the traces, the method comprising the steps of:a) selecting and providing a ratio of the percentage area of unbacked to backed area for the traces to obtain a desired differential mode impedance for the traces; and b) providing a conductive island in the conductive layer in the at least one aperture with the island electrically isolated from the conductive layer of the load beam to adjust the ratio of the backed area formed by the conductive layer of the load beam and the backed area formed by the island.