Hi Jauwhei Hong - I can echo Jan's reply - we are soldering SOT's with a dual wave system with only minor problems. Our flux is a low residue material that could be used in a no-clean mode. It has been my experience that the SOT's seem to be a bit less solderable than other components and that your flux selection will have a big impact on your final solder joint fillet. Try a couple of different fluxes and see if you get different results. Good Luck. Dave Hillman Rockwell Collins [log in to unmask] ______________________________ Reply Separator _________________________________ Subject: Re: (ASSEM) Wave soldering SOT-23 Author: [log in to unmask] at ccmgw1 Date: 12/12/96 5:12 AM > Tom: > > If you are using no-clean flux to solder SOTs (or anything with tall, > non-solderable body that will repel the wave from reaching the pad, such as > tantalum capacitors), dual wave would not work. This is because the first > wave (chip or turbulant wave) will kill the flux, resulting in the poor > solderability at the second wave (lambda wave). The way we do it rather > successfully is to elongate the pad size and solder them with a vibrating > wave (omega wave), which has much lower surface energy to reach any shadowed > pads. Good luck. > > Regards > Jauwhei Hong > [log in to unmask] Jauwhei Hong, We don't have any problems soldering SOT's with no-clean flux and dual-wave (chip & lambda). We get fine results if we only use an angle of 4 degrees, accurate dwell time for the specific pcb and a "perfect" preheat profile. We also don't have to elongate the pad sizes, we use the ordinary sizes the pick & place do. i don't know, but are we different? /Jan Merstrand Operation Engineer Ericsson Microwave Systems [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] * ***************************************************************************