Process in PCB manufacture, in which holes are cleared of pre-preg seepage, prior to metallisation.

A process by which an amount of printed wiring board substrate material (glass and epoxy, but not copper) is dissolved or otherwise rioved from the walls of drilled holes. The purpose of etchback is to expose a greater inner layer copper surface area for interconnection with subsequently plated copper.

The controlled removal of all components of base materialby a chemical process on the side wall of holes in order to expose additional internal conductor areas.