Method of manufacturing a printed wiring board

摘要

A manufacturing method of a printed wiring board, wherein a conductor circuit (106) is formed on the surface of an insulating substrate (107). A solder resist made of thermosetting resin is next printed on the surface of said insulating substrate (107). An insulating film (101) having a coefficient of thermal expansion equal to or smaller than 100 ppm/°C is next formed by thermally curing the solder resist. The conductor circuit (106) is next exposed by irradiating a laser beam to an opening portion forming portion in the insulating film (101) and burning-out the insulating film (101) of said opening portion forming portion and forming an opening portion (110).