We plug from the bottom side only. If the bottom side is plugged, no flux can get to the top when spray fluxed. No reliability problems have been found. I would be more worried about HASL flux and bare copper in the via than about wave soldering, which uses considerably less aggressive flus. ______________________________ Reply Separator _________________________________ Subject: Re: Tented vias??? Author: [log in to unmask] at internet Date: 12/5/96 5:46 AM Gary, We at GenRad have all our VIA's Plugged & tented for just this reason, however we are do note probe on the through VIA's, but to add extra bottom side Test Pads for ICT. This does cause 1 or 2 problems at the design stage, but gives great benifits for out Test department, who get much better throughput, & much more reliable results. ________________________________________________________________________ | [log in to unmask] David Tandy. EDA Specialist. GenRad ADS. | | Tel: (+44) 161 491 9191 Orion Business Park, Bird Hall Lane, | | Fax: (+44) 161 491 9106 Stockport, Cheshire, SK3 0XG, England. | |________________________________________________________________________| > Colleagues: > > Our in house SMT assembly facility has asked that we tent our vias on top and > bottom sides to aid in solder bridge reduction. If bottom tenting is not > possible becaues vias may double as test points, they ask that we still tent > the top (component) side. They use a no clean process. > > I am concerned that contaminants will be trapped in vias tented only on one > side and cause premature failure down the road. Normal via size is .012. > What are your thoughts on tented vias??? One side? Both sides? Not tented > ever? Why??? What other problems may we encounter? > > Thanks in advance for your opinions. > > > gary ... > > *************************************************************************** > * TechNet mail list is provided as a service by IPC using SmartList v3.05 * > *************************************************************************** > * To unsubscribe from this list at any time, send a message to: * > * [log in to unmask] with <subject: unsubscribe> and no text. * > *************************************************************************** > * If you are having a problem with the IPC TechNet forum please contact * > * Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask] * > *************************************************************************** > > *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To unsubscribe from this list at any time, send a message to: * * [log in to unmask] with <subject: unsubscribe> and no text. * *************************************************************************** * If you are having a problem with the IPC TechNet forum please contact * * Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask] * *************************************************************************** *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To unsubscribe from this list at any time, send a message to: * * [log in to unmask] with <subject: unsubscribe> and no text. * *************************************************************************** * If you are having a problem with the IPC TechNet forum please contact * * Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask] * ***************************************************************************