PCB Via Protection Types

The function of PCB via protection is a guarantee for solderability, reliability, and long-tern circuit performance. According to IPC-4761, vias are defined as protected through different structures such as tented vias, plugged vias, filled vias, covered vias, and capped vias.PCB designers strategically select the via protection type, balancing the cost, manufacturability, solder mask performance, signal integrity, and reliability requirements in multilayer boards, HDI circuits, automotive electronics, industrial controls, and other demanding PCB applications.

What are the types of vias in PCB?

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.