There are many ways to make viaholes. There are also many ways to plugg the viaholes with epoxy or solder resist. Because no international standard define viahole types, there is always a risk that there will be misunderstanding between designer and producer of PCB. To make it easier Civa has made a table of every type of viaholes.
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|
Type |
Comment |
|
A |
Plated through hole |
|
|
B,C |
Buried via |
Produced as plated through hole |
|
D |
Semiburied via |
Produced as plated through hole |
|
E |
Blind via |
Mechanical drilled after lamination |
|
E |
Blind microvia |
Laser drilled after lamination |
|
F |
Plugged via |
Produced as plated through holeThen filled with epoxy and plated. |
Plugged via is first produced as plated through hole. The the hole is filled with epoxy. The plated copper is etch down on the surface and then the panel go to a second plating. The main advantage with this process is that you can have via in the