Electric circuit card having a donut shaped land

摘要

A metal carrier has a dielectric material with a thickness of less than 0.004 inch and electrical voltage insulation characteristics of at least 2500 volts formed on a surface. A donut configured land defines at least one via or opening for removing dielectric material selectively. Reflow solder is used to form electrical interconnections, and the vias provide thermal dissipation sufficient to conform to safety requirements.