Via is very important element when engineers design the PCB. And usually there are several types via including Through hole and Blind via and buried via also Laser Drilling via etc...below are some details information about those vias.
Through hole
A through hole means the drilling machine will dilling the board from the top to the bottome and cross the board so when sodering the pins of the components can be soderdered through hole.
Blind Via
A blind via extends to only one surface of the printed circuit board. Blind vias may be used for SMT or BGA pads. Because blind vias touch the surface on one side of the board they may be accessible to physical probes.
Buried Via
A buried via does not extend to either surface of the printed circuit board. Buried vias are not directly accessible to external probes.
Not plated via
Not plated vias means on the side of the vias doesn't have cooper inside.
The through-hole technology, also spelled "thru-hole" are holes that go completely through the boards. But different from PTH the NPTH don't need plating the cooper iniside.
Through hole plated
Through-hole technology almost completely replaced earlier electronics assembly techniques such as wire wrapping. From the second generation of computers in the 1950s until surface-mount-technology (SMT) became popular in the late 1980s, every component on a typical PCB was a through-hole component.
Tented capped:
This is the easiest and least costly process—actually there is no added cost for this process. Simply remove the mask clearances from the vias you wish to have tented. Tenting a via simply means to cover the annular ring and via hole with solder mask. No special steps are taken to ensure the hole opening remains closed. Tenting a via will sometimes result in the hole remaining covered but it isn't guaranteed. Smaller diameter vias (12mil diameter or less) have the best chance of remaining closed. The main purpose for tenting shouldn't be to close the opening of a hole but rather, cover the annular ring to prevent exposure to the elements and reduce accidental shorting or contact with the circuit.
Plugged:
Usually we can use resin or sorder mask to plug the vias. With a mask plugged via, (a.k.a. Mask Filled or Non-Conductive Filled via), specific measures are taken to ensure the via is plugged and sealed with mask and the annular ring is covered. A common application for this is on a BGA design where vias are commonly found in very close proximity to the BGA’s SMD pads. The concern is during assembly, solder will wick away from the intended pad and flow down the via creating poor or non-existent solder joints.
