Method for manufacturing terminal contacts for thin-film magnetic heads

Claim 1

A method for manufacturing terminal contacts for thin-film magnetic heads on a substrate that is subdivided along parting lines into individual substrate elements each having two write/read heads, whereby a surface of the substrate is covered surface-wide with an electrically conductive permalloy layer that has at least a plurality of contact locations each having contact lugs directed toward the magnetic head and is structured by ion beam etching into a structured permalloy layer, and whereby the structured permalloy layer is covered surface-wide with a protective layer of aluminum oxide except for the contact locations that are provided with an electro-deposited gold film for the attachment of a bonding wire, the method comprising the steps of: masking the electrically conductive permalloy layer of the substrate and simultaneously defining interconnects that short the contact lugs; covering the masked permalloy layer with a photoresist layer and forming contact windows that expose the permalloy layer in the photoresist layer at the contact locations by an exposure and development process; electrolytically applying a copper layer over the exposed permalloy layer in the contact windows, the thickness of the copper layer being smaller than that of the photoresistive layer; removing the residues of the photoresistive layer from the electrically conductive permalloy layer and subsequently structuring said permalloy layer; applying the protective aluminum oxide layer surface-wide over the structured permalloy layer including the copper layer, and thereafter mechanically eroding to said aluminum oxide layer to such an extent that the remaining residues of the protective layer form a flush surface with the copper layer; cleaning the resulting surface and electro-depositing the gold film for securing the bonding wires thereon in punctiform fashion at the contact locations; and then eliminating the shorts between the contact lugs by cutting the interconnects, said interconnects being eliminated before testing the magnetic heads and before separation of the individual substrate elements.

Claim 2

A method for manufacturing terminal contacts for thin-film magnetic heads on a substrate that is subdivided along parting lines into individual substrate elements each having two write/read heads, whereby a surface of the substrate is covered surface-wide with an electrically conductive permalloy layer that has at least a plurality of contact locations each having contact lugs directed toward the magnetic head and is structured by ion beam etching into a structured permalloy layer, and whereby the structured permalloy layer is covered surface-wide with a protective layer of aluminum oxide except for the contact locations that are provided with an electro-deposited gold film for the attachment of a bonding wire, the method comprising the steps of: masking the electrically conductive permalloy layer of the substrate and simultaneously defining interconnects that short the contact lugs; covering the masked permalloy layer with a photoresist layer and forming contact windows that expose the permalloy layer in the photoresist layer at the contact locations by an exposure and development process; electrolytically applying a copper layer over the exposed permalloy layer in the contact windows, the thickness of the copper layer being smaller than that of the photoresistive layer; removing the residues of the photoresistive layer from the electrically conductive permalloy layer and subsequently structuring said permalloy layer; applying the protective aluminum oxide layer surface-wide over the structured permalloy layer including the copper layer, and thereafter mechanically eroding to said aluminum oxide layer to such an extent that the remaining residues of the protective layer form a flush surface with the copper layer; cleaning the resulting surface and electro-depositing the gold film for securing the bonding wires thereon in punctiform fashion at the contact locations; and then eliminating the shorts between the contact lugs by cutting the interconnects, said interconnects being eliminated before testing the magnetic heads and before separation of the individual substrate elements.