An active thin-film magnetic head with 60 MHz bandwidth and internal amplification of 58 dB

An integrated circuit that realizes such a monolithic combination of a thin-film magnetic head with a preamplifier in bipolar technology is described. It yields recording densities up to 2000 fc/mm on a flexible disk by the head, and provides a read signal amplification of 58 dB by the semiconductor circuit (SCC). Thus, signal levels up to 100 mV are attainable, which is typically more than 100 times larger compared with conventional heads. The combination of the normally incompatible thin-film and bipolar technology was possible by an appropriate choice of processing steps and two protective layers which allow the application of the necessary thin-film processes after fabrication of the SCC