Patent ID: 6482569
Filing Date: 2002-11-19
Classification: G03F,H05K

Abstract:
A process for forming a polyimide pattern which comprises the steps of:(1) selecting a polymeric polyimide precursor which has an amide bond density of at least 1.5 mol/kg from the group consisting of polymeric aromatic polyimide precursors which have a repeating unit represented by the formula whereinX is an unfluorinated aromatic ring bonded to at least four substituents, or an unfluorinated structure bonded to at least four substituents that is composed of up to a total of four aromatic rings linked to each other via single bonds, and wherein X further comprises an electron-donating group lacking hydrogen, which is an aryloxy group, and is attached to the aromatic ring bonded to the CONH substituent; â€”COR and â€”CORâ€² are substituents that occupy the ortho positions of aromatic ring X with respect to the CONH substituent; R and Râ€² are OR1 wherein R1 is a group containing a carbon-carbon double bond; and Y is an unfluorinated aromatic ring, bonded to at least two substituents, or an unfluorinated structure, bonded to at least two substituents, that is composed of up to a total of six aromatic rings linked together via bonds to at least one type of linker selected from the group consisting of O, S, CO, CH2, (CH3)2C, SO, SO2 and a single bond; (2) applying a film of a photosensitive composition, which comprises the polymeric polyimide precursor, a photopolymerization initiator and a solvent and which, at a thickness of 10 &mgr;m, exhibits an absorbance of 1.5 or less upon exposure to light of wavelength of 365 nm, to an article capable of being covered by the film; (3) exposing the applied film to monochromatic i-line light by using an i-line stepper; (4) removing unexposed areas of the film with a developing solution to form a pattern; and (5) heat-curing the resultant pattern.