Increase in printed circuit conductor width caused by plating build-up or by undercutting during etching.
OutgrowthThe increase in conductor width at one side of a conductor, caused by plating build-up, over that delineated on the production master.
OutgassingThe gaseous emission from a laminate printed board or component when the board or the printed board assembly is exposed to heat or reduced air pressure or both.
OSPOrganic Solderable Preservative.
Organic_Activated_(OA)A water-soluble flux using organic acids as activators.
OpenAn area of a bare PCB which, due to over-etching or fabrication problems, separates two electrically connected points.
One_sided_BoardSee Single-sided Board.
OmegameterA test instrument measuring ionic residues on PCBs via the drop of resistivity over a specific time.