Resin film for flexible printed circuit board, metal foil provided with resin, coverlay film, bonding sheet, and flexible printed circuit board

The present invention pertains to a resin film for a flexible printed circuit board, the resin film comprising: a long-chain alkyl bismaleimide resin having a main chain including an alkylene chain that has a carbon number of 10 or more, and a side chain including an alkyl group bonded to the alkylene chain; and a resin composition containing a curing agent having two or more functional groups for reacting with the long-chain alkyl bismaleimide resin.