PCB Via Protection Types

Overview of PCB Via Protection Types According to IPC-4761 Standard

Vias Holes (According to IPC-4761)
Tented Via (Type I Via)	A via with a dry film mask material applied bridging over the via wherein no additional materials are in the hole. Single-sided tented is not recommended.
Tented and Covered Via (Type II Via)	A Type I via with a secondary covering of mask material applied over the tented via. Single-sided tented and covered is not recommended.
Plugged Via (Type III Via)	A via with material applied allowing partial penetration into the via. Single-sided plugged is not recommended.
Plugged and Covered Via (Type IV Via)	A Type III via with a secondary covering of material applied over the via. Single-sided plugged and covered is not recommended.
Filled Via (Type V Via)	A via with material applied into the via targeting full penetration and encapsulation of the hole.
Filled and Covered Via (Type VI Via)	A Type V via with a secondary covering of material (liquid or dry film soldermask) applied over the via.
Filled and Capped Via (Type VII Via)	A Type V via with a secondary metallized coating covering the via. The metallization is on both sides.