DLC coating for video head

The effect of the thickness of DLCs sputtered on video heads upon the value of the playback signal and visibility of the gap in the ferrite surface wa s examined. It was found that DLCs improve the wear resistance of the heads , whereas the playback quality depends on the probability of the DLC peelin g off during friction on the video tape. Technological regimes involving va cuum-pulsed are sputtering of graphite in combination with ionic bombardmen t of the ferrite surface and the DLC were worked out. These regimes provide a good adhesion and smoothness of the film surface. Tests of video heads c overed with DLCs showed that the wear resistance and the 'still frame' time of these heads are several times larger than those of standard video heads . A reliable and highly efficient commercial technology for the production of DLC video heads has been developed. (C) 1999 Elsevier Science S.A. All r ights reserved.