Now this was an excellent and most helpful posting, Stephen! Thanks from all of us.



-----Original Message-----

From: TechNet <[log in to unmask]> On Behalf Of Stephen Pierce

Sent: Wednesday, August 21, 2019 4:36 PM

To: [log in to unmask]

Subject: Re: [TN] TYPE III vs TYPE V vias



Jack,



You're asking for Type V (w/ a non-conductive fill material)  and getting Type III (w/ soldermask material).



The intent of Type III is to simply plug the through holes, whereas the intent of Type V is to completely fill the through holes. For type III, plugging with soldermask can be done from either side or both sides, the latter case being riskier because of the likelihood of trapping air and/or contaminants in the center of the hole (between the plugs). Type V assumes a separate (as opposed to soldermask), non-conductive material is used specifically to completely fill the holes prior to the application of soldermask.



Fill material colors typically fall somewhere between white and gray, although I am aware of an OEM that specs a black color. No green.



Stephen Pierce