We have an existing design PWA with socket mounted parts.  The design has 
vias under the sockets as well as PTH under the sockets that were intended 
for use as spares to facilitate future design changes.  The sockets are of 
the open construction frame type (an H configuration), or otherwise are 
body-less sockets.  We are considering removing all sockets and direct 
soldering the components into the existing PTH using ORL0 type flux.

We are concerned about flux residue and other forms of contamination such as 
from the PWB manufacturing process and the PWA assembly process getting into 
the open via and spare PTH and not being removed by the in-line cleaning 
system.

We are considering having the vias and spare PTH tented in some fashion.  We 
need to retain use of the tented spare PTH for future use if needed.  What 
method do folks recommend to tent vias on equipment that was already 
designed with un-tented vias and spare PTH?

On a go forward basis, we are considering mandating that if vias are used 
under components, they must be tented and we will not allow spare PTH under 
any component.  Allowing spare PTH under open frome or bodyless sockets was 
a dumb idea.

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