Thin film head, producing method thereof and magnetic disk apparatus

摘要

A thin film head having reading part and recording part having an upper magnetic pole front end layer and a lower magnetic pole having a lower magnetic main layer, a lower magnetic pole front end portion on the lower magnetic main layer, and a projection step portion on the lower magnetic pole front end portion. The upper magnetic pole front end layer has a magnetic pole expansion position and a length from an air bearing surface to the magnetic pole expansion position is less than a length from the air bearing surface to gap depth position of the lower magnetic pole front end portion.