Process of forming a patterned polyimide film and articles including such a film

A process of forming a patterned polyimide film comprising the steps of

• (a) forming a mask resistant to a chemical imidizing reagent on a film of polyimide precursor on a substrate,
• (b) contacting only an unmasked portion of said film with the chemical imidizing reagent to effect imidization of the precursor at the unmasked portion to form polyimide, and
• (c) forming said film into a pattern of a polyimide by removing the precursor at selected portions beneath the mask.

A process of manufacture of an electronic device having a patterned polyimide insulation film which comprises forming a coating of a polyimide precursor on the electronic device, forming a mask on the coating, contacting unmasked portions of the polyimide precursor with a chemical imidizing reagent thereby converting the polyimide precursor into polyimide, and removing portions of the polyimide precursor beneath the mask.

A process of manufacture of a semiconductor device having at least two insulating layers of patterned polyimide and at least one patterned conductor layer interposed between the insulating layers, comprising forming a mask on each of the patterned polyimide precursor film corresponding to the insulating layers, bringing the precursor into contact with a chemical imidizing reagent thereby to effect imidization of the precursor at the exposed portions into polyimide, and removing the precursor beneath the mask to form a desired pattern.

A process of manufacture of a semiconductor memory device having an .alpha.-ray shielding layer in the form of a patterned polyimide film which comprises forming a coating of a polyimide precursor on the memory device, forming a mask on the coating, contacting unmasked portions of the polyimide precursor with a chemical imidizing reagent thereby converting the polyimide precursor into polyimide, and removing portions of the polyimide precursor beneath the mask.

A process of manufacture of a thin-film magnetic head comprising forming as thin films on a substrate a lower magnetic layer, a conductor layer, an upper magnetic layer and patterned insulating layers insulating said conductor layer from said upper and lower magnetic layers, wherein said patterned insulating layers are each formed by forming a coating of a polyimide precursor, forming a mask on the coating, contacting unmasked portions of the polyimide precursor with a chemical imidizing reagent thereby converting the polyimide precursor into polyimide, and removing portions of the polyimide precursor beneath the mask.

A process of manufacture of a heat-sensitive printing head comprising forming patterned insulating layers and wiring on a substrate, wherein each of said insulating layers is formed by forming a coating of a polyimide precursor, forming a mask on the coating, contacting unmasked portions of the polyimide precursor with a chemical imidizing reagent thereby converting the polyimide precursor into polyimide, and removing portions of the polyimide precursor beneath the mask.

A process of manufacture of a magnetic memory device comprising forming on a substrate a conductor pattern, a magnetic pattern and a patterned insulating layer between said conductor pattern and said magnetic pattern, wherein said patterned insulating layer is formed by forming a coating of a polyimide precursor, forming a mask on the coating, contacting unmasked portions of the polyimide precursor with a chemical imidizing reagent thereby converting the polyimide precursor into polyimide, and removing portions of the polyimide precursor beneath the mask.

A process of manufacture of a circuit board comprising forming a plurality of wiring layers and a plurality of patterned insulating layers on a ceramic substrate, wherein each of said patterned insulating layers is formed by forming a coating of a polyimide precursor, forming a mask on the coating, contacting unmasked portions of the polyimide precursor with a chemical imidizing reagent thereby converting the polyimide precursor into polyimide, and removing portions of the polyimide precursor beneath the mask.

A process of manufacture of a flexible circuit board comprising forming a patterned polyimide substrate and wiring thereon, wherein said substrate is formed by forming a polyimide precursor film, forming a mask on the film, contacting unmasked portions of the polyimide precursor film with a chemical imidizing reagent thereby converting the polyimide precursor into polyimide, and removing portions of the polyimide precursor beneath the mask.

A process of manufacture of a semiconductor element package comprising mounting a semiconductor element on a substrate, forming wiring connected to said element, forming at least one patterned insulating layer for said wiring and a patterned coating layer above said wiring, wherein each of said patterned insulating layers and said patterned coating layer is formed by providing a polyimide precursor film, forming a mask on the polyimide precursor film, contacting unmasked portions of the polyimide precursor film with a chemical imidizing reagent thereby converting the polyimide precursor into polyimide, and removing portions of the polyimide precursor beneath the mask.