Hi Poh, You do not say anything about the QFP leads. You most likely had no wetting to the leads. Observe the solder joints remaining on the PCB pads; if you can see a clear outline of the lead foot in the the solder, you have a clear indication of inadequate wetting. This could then be a reflow process issue (inadequate reflow heat), a solderability issue (leads are not solderable because of contamination/oxidation —remember, plated but not reflowed tin/lead does not protect the underlying surface very well nor has the surface had to be solderable at the time of tin/lead plating), or an improper lead material (some lead materials, e.g., Alloy 42, BeCu, have been known to be difficult or impossible to solder). Please let us know what you find. Werner Engelmaier Engelmaier Associates, L.C. Electronic Packaging, Interconnection and Reliability Consulting 7 Jasmine Run Ormond Beach, FL 32174 USA Phone: 904-437-8747, Fax: 904-437-8737 E-mail: [log in to unmask] ################################################################ 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 ################################################################