Patent ID: 9468091
Filing Date: 2016-10-11
CPC Classification: H05K

Claim Text:
1. A circuit board comprising: an insulating substrate; and an electrically conductive unit including a first electrically conductive layer formed on said insulating substrate, and a second electrically conductive layer stacked on said first electrically conductive layer, said first and second electrically conductive layers respectively having outer peripheral marginal regions which are configured in a stepped arrangement such that said first electrically conductive layer is configured to have an area dimension larger than that of said second electrically conductive layer, and a thickness not greater than that of said second electrically conductive layer, so as to minimize stress caused by a difference in coefficients of thermal expansion between said electrically conductive unit and said insulating substrate, wherein said first and second electrically conductive layers are made from the same electrically conductive metal material.