{TAIL ~ The present inventors} have conducted elaborated studies with the aim of developing a polyamide acid, i.e. polyimide precursor, having photosensitive groups in its main chain which is endowed with about 20 100 times as high a photosensitivity as that of prior products and a heat resistance of {HEAD ~ 400° C.} or above after dehydration cyclization 
{ TAIL ~ The present inventors } have conducted elaborated studies with the aim of developing a polyamide acid , i.e. polyimide precursor , having photosensitive groups in its main chain which is endowed with about 20 100 times as high a photosensitivity as that of prior products and a heat resistance of { HEAD ~ 400 ° C. } or above after dehydration cyclization
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