US 6,714,385 B1
Apparatus and method for controlling common mode impedance in disk drive head suspensionsGeneral
US 6,714,385 B1
Apparatus and method for controlling common mode impedance in disk drive head suspensions
Tech Center:
2600 Communications
Examiner:
William Klimowicz
Art Unit:
2652 Videophones and Telephonic Communications; Audio Signals; Digital Audio Data Processing; Linguistics, Speech Processing and Audio Compression
Agent:
Inventors:
Marc A. Even; Larry C. Webb
Assignee:
Priority:
04/16/01
Filed:
04/16/01
Granted:
03/30/04
Expiration:
11/17/21
Abstract
Apparatus and method of adjusting the common mode impedance while enabling maintenance of the differential mode impedance of a pair of traces located with respect to a ground plane formed by a load beam or trace assembly of a disk drive head suspension. The ground plane has apertures with isolated conductive islands in the apertures for setting a desired common mode impedance. The method includes a cut and try approach using sample coupons to adjust the ratio of backed area to island area to adjust the common mode impedance while maintaining the differential mode impedance by maintaining the ratio of unbacked area to the sum of the backed and island areas.