Understanding 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 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 Not Recommended.

Plugged Via (Type III Via)
　　A via with material applied allowing partial penetration into the via.Single Sided Plugged Not Recommended.

Plugged and Covered Via (Type IV Via)
　　AType III via with a secondary covering of material applied over the via.Single Sided Plugged and Covered Not Recommended.

Filled Via (Type V Via)
　　A via with material applied into the via targeting a 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.