Hi All, We have a BNC connector that is put through reflow and wave solder with water washes after each soldering operation. The customer has been returning some product because the BNC connectors are turning black in the field. Cross-sectional and SEM/EDS analysis show that the connector has a ferrous base-metal with copper overplate. Nickel is plated on top that contains about 5%phosphorous. The "bad" connectors have a Ni thickness of 0.1mil and the "good" connector has Ni thickness of 0.2mil. A trace of copper was detected on the "bad" connectors (about 1%). What could be causing the black oxide? Could it be copper oxide from solid state diffusion of the copper through the nickel barrier? Other ideas? Some of the units were in the field for 6 months to a year. Thanks Scott ************************************************************************ ***************************** Scott M. Severson QA/FA Lab Manager "Space and Time are not conditions in which we live, Benchmark Electronics Inc. but modes in which we think." 4155 Theurer Blvd. Winona, MN 55987 ---Albert Einstein (507)452-8932 ************************************************************************ ***************************** ################################################################ 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's web site (http://www.ipc.org) "On-Line Services" section for additional information. For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312 ################################################################