Hello,

1) what is electrical via in PCB ?
2) what purpose we are using the electrical via ?
3) If I want to placed this electrical via outside of the thermal relief, how we can place it ? Please can you show me as picture for just understanding!!!

If we use thermal vias, these vias are connected to ground.
If we use electrical vias, where we can connect these vias ?

 

hi,
Look at pages # 8 and #22 of this PDF.
E

 

A via is simply a special case of a plated thru hole (PTH). The sole purpose is not to provide a point for soldering a lead but just an electrical connection between layers.

A via is oft covered by the solder mask for additional protection. This covering may or may not fill the hole, though I have never seen this as cause for rejection.

In any layout program a via may be placed most anywhere between two points that are defined in the netlist to connect.

 

If we use thermal vias, these vias are connected to ground.

Not necessarily. It could as well be any other net, like for example in case of an smd mosfet - then you would most likely use thermal vias that are electrically connected to the drain of that transistor.

If we use electrical vias, where we can connect these vias ?

To those electrical nets.
Via is just a pice of copper that connects different layer on the pcb, and it is allways connected to some net, be it ground or vcc or whatever else. A thermal via is a special case, where the via is not really used for its electrical connection, but mainly as a chunk of copper that conducts the heat from one side of the pcb to the other.