We need some basic information on application of ultrasonic vibrators for vertical , racks operated PTH line . We are plating 0.25 , 0.30 and 0.35 mm via holes . Desmear process is applied off PTH line . In some of small via holes we found round , circular voids in the center of the hole . It looks like typical void created by air bubble . We have allready pneumatic vibratotrs in the PTH line , but we intend to install ultrasonic vibrators in the conditioner , which is the first solution in the line . The questions are : 1 ) Power ( watts ) per plated area ? Does it depends on hole size and board thickness ? 2 ) Recommended frequencies ? 3 ) What is the recommended distance between the transducer and the boards? 4 ) What percentage of the energy actually reach the center of the hole ? How distance between the transducer and the board affect the amount of ultrasonic energy that actually reach the board ? All practical recommendations will be appreciated ! Edward Szpruch Eltek Ltd - Israel Tel 972 3 9395050 Fax 972 3 9309581 E-mail : [log in to unmask] *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To subscribe/unsubscribe send a message <to: [log in to unmask]> * * with <subject: subscribe/unsubscribe> and no text in the body. * *************************************************************************** * 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] * ***************************************************************************