Manufacturing method and an electronic component device of an electronic component device

PROBLEM TO BE SOLVED: To provide a method for manufacturing an electronic component device capable of improving a yield even when collectively manufacturing a plurality of electronic component devices, and the electronic component device manufactured by the method.SOLUTION: A method for manufacturing an electronic component device includes a heating step of joining an electronic component and a substrate via a plurality of bumps by heating the electronic component by a heating member via a buffer sheet in a state in which the electronic component and the substrate are in contact with each other via the plurality of bumps.SELECTED DRAWING: None