Hi Paul - is it possible that you have a flux "bubble" due to flux evolution that prevents solder from getting to a pad? You lost me on the flux you are using - is it a type R (sorry TechNet, I know that nomenclature is no longer valid)? What is a SM/NA flux? The flux bubble theory would explain the randomness that you are seeing - there has been flux evolution issues in the past that have resulted in some of the wording currently found in the ANSIJ-STD-002/003 specifications. Good Luck. Dave Hillman Rockwell Collins [log in to unmask] [log in to unmask] on 04/16/98 10:22:57 AM Please respond to [log in to unmask]; Please respond to [log in to unmask] To: [log in to unmask] cc: (bcc: David D Hillman/CedarRapids/Collins/Rockwell) Subject: [TN] FAB: Ni/Au Solderability test Hello all, Our standard solderability test for HASL or Reflowed Tin-Lead finish is 5 seconds at 235 C (455 F) using non-activated SM/NA Flux on a static solder bath. We are seeing odd instances of missed pads on Electroless Nickel/Immersion Gold finish where the solder has not touched the pad at all. This only occurs on random isolated pads, sometimes one in a row of SMD pads, and I am wondering whether the test parameters should be slightly different for this finish or if there is a problem with the test rig. The majority of pads have tinned and solderability on these is very good. Any input on test parameters used elsewhere would be appreciated. -- Paul Gould [log in to unmask] Isle of Wight,UK ################################################################ TechNet E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c ################################################################ To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TechNet <your full name> To unsubscribe: SIGNOFF TechNet ################################################################ Please visit IPC web site (http://jefry.ipc.org/forum.htm) for additional information. For the technical support contact Dmitriy Sklyar at [log in to unmask] or 847-509-9700 ext.311 ################################################################ ################################################################ TechNet E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c ################################################################ To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TechNet <your full name> To unsubscribe: SIGNOFF TechNet ################################################################ Please visit IPC web site (http://jefry.ipc.org/forum.htm) for additional information. For the technical support contact Dmitriy Sklyar at [log in to unmask] or 847-509-9700 ext.311 ################################################################