A semiconductor device includes a first package, a second package, a contact part for electrically coupling a first wiring pattern to a second wiring pattern, and a reinforcer. The thermal expansion coefficient of the first package is larger than that of the second package. The second package is disposed so that the second interposer overlaps the first semiconductor chip and the first interposer. The contact part is provided between the first and second interposers so that a first end is coupled to the first wiring pattern and a second end is coupled to the second wiring pattern. The reinforcer is provided to expose part of the contact part and cover the circumference of the first end of the contact part.