Use of high performance resins for the planarization of magnetic rigid disk substrates

A high-performance thermoset polymer, benzocyclobutene, has been used to planarize magnetic rigid disk, substrates. Typically, one layer (1-5 μm thick) of spin-coated and cured material is applied to either rough (R_A=200 nm) or smooth (R_A=20 nm) Al substrates with no further processing, resulting in R_A´s of 1-2 nm and flatness about 1 μm. Various magnetic media have been coated on the resin planarized substrates, including both particulate and sputtered high-coercivity thin film, with resultant magnetic and recording properties comparable to those obtained with Ni(P)-Al substrates. The planarizing resin can be used with Al, ceramic, and other types of substrates, and can be textured. It offers performance equivalent to that of Ni(P)