Printed wiring board with improved plated through hole fatigue life

摘要

A printed wiring board having a layered composite of metal planes and dielectric layers. At least one of the dielectric layers has a modulus lower than the modulus of the remaining dielectric material layers. A plating, extending through the layered composite, has a first land on a first external surface of the layered composite, a second land on a second external surface of the layered composite, and a barrel extending between the first land and the second land. The lower modulus dielectric material layer deforms during thermal excursions of the printed wiring board in such a way as to reduce the strains imposed on both the lands and the barrel of the plated through holes.