Prevention of Plug Buildup in Circuit Board through Holes During Photo Image Development
Original Publication Date: 1980-Oct-01
Included in the Prior Art Database: 2005-Feb-13
Typical printed circuit boards range in thickness from approximately 4.44 mm (0.175") to approximately 5.1 mm (0.2"). The circuitized boards can have large numbers of plated through holes (PTH) with very small inside diameters. A coating process is known for applying protective film coating to the external surfaces of circuitized boards.