DEVELOPMENT OF THIN-FILM LAMINATED HEAD F OR DIGITAL VTR

Three improvements have been performed to apply to a thin film laminat ed head for DVC: (1) Good tribology characteristics and high permeabil ity of FeAlSi film have been achieved by using a new ceramic substrate . (2) Magnetostriction correlates well with reproducing efficiency. Hi ghly (111)-oriented FeAlSi film is formed on amorphous like iron by re active plasma evaporation, so that magnetostriction is controlled belo w 1 x 10(-6) and output signal from the head increases. (3) V-shaped g rooves are formed by ELID (Electrolytic inprocess dressing) abrasive p rocess. Their surface roughness is below 100 nm. The thin film laminat ed head is superior to MIG (Metal in gap) head. The output signal leve l is 2 dB higher and optimum recording current is 3.5 dB lower.