Photosensitive resin composition, production method for polyimide cured film using same, and polyimide cured film

A polyimide cured film which has a dielectric loss tangent of 0.003 to 0.011 as measured at a frequency of 40 GHz by the perturbation type split cylinder resonator method, and has RFA of 0.81 to 0.93, and satisfies the following formula:

• 85
• <
• RFA
• /
• tan
• ⁢
• δ
• 40
• <
• 175
• wherein RFA represents a residual film ratio after heat curing (ratio), and tanδ40 represents the dielectric loss tangent as measured at a frequency of 40 GHz by the perturbation type split cylinder resonator method.

A method for producing a copolymer containing a polyimide and polyimide precursor, the method comprising the following:

• (i) subjecting a first tetracarboxylic dianhydride or an acid/substituent adduct thereof to a condensation reaction with a first diamine compound for imidization to obtain a diamine oligomer having a repeating unit of a polyimide structure;
• (ii) subjecting the diamine oligomer to a condensation reaction with a second tetracarboxylic dianhydride or an acid/substituent adduct thereof to synthesize a polyimide-imide precursor moiety having a polyimide block moiety;
• and
• (iii) subjecting the polyimide-imide precursor moiety to a condensation reaction with a third tetracarboxylic dianhydride or an acid/substituent adduct thereof and a second diamine compound to synthesize a polyimide precursor moiety, wherein the first tetracarboxylic dianhydride, the second tetracarboxylic dianhydride and the third tetracarboxylic dianhydride may be the same as or different from each other, at least one of the second tetracarboxylic dianhydride and the third tetracarboxylic dianhydride is in the form of an acid/substituent adduct having a photopolymerizable functional group, and the first diamine compound and the second diamine compound may be the same as or different from each other.