CROSSLINKED POLYIMIDE RESIN, METHOD FOR PRODUCTION THEREOF, ADHESIVE RESIN COMPOSITION, CURED MATERIAL THEREOF, COVERLAY FILM, AND CIRCUIT BOARD

摘要

PROBLEM TO BE SOLVED: To provide a crosslinked polyimide resin capable of forming an adhesive layer which has a stable coating performance even when producing in an industrial scale, is excellent in solder heat resistance and is capable of holding an excellent adhesive performance for a long period under high-temperature environment.SOLUTION: A crosslinked polyimide resin is obtained by reacting polyimide having ketone groups with an amino compound having at least two primary amino groups as a functional group, and has a crosslinked structure in which the amino group of the amino compound reacts with at least a portion of the ketone group in polyimide to form a C=N bond. The resin has a sea-island phase separation structure. For details, when the phase difference in phase imaging in observation by an atomic force microscope is 20° or more in such a state as processed to a sheet shape, a small phase is made to be 0 and a large phase to be 100. When defining the area in the range of 0 to 30 in the phase difference converted to 100 as a land, and the area other than the land as a sea, at least one land area having the area within the range of 20 μmor more and 140 μmor less is present in an observation area of 3,600 μm.SELECTED DRAWING: Figure 5