Definition

Non-Plated Through Hole (NPTH) is a drilled hole that does not receive copper plating. NPTHs are used for mechanical mounting (screws, standoffs), alignment pins, or component body clearance where electrical connection is not needed. In design files, NPTHs must be clearly distinguished from PTHs, typically in separate drill files. Inner layer copper must have adequate clearance around NPTHs to prevent shorts. Solder mask openings over NPTHs are common to allow access.