We are reflowing ceramic resonators and are finding their tops falling/popping off when handling the pcbs during final assy. The epoxy seems to be coming off the components base and adherring to the lid. The components are "RFM resonators", case type "SM-2". The max case temp is 250 degC. We are using an IR reflow oven with a profile around 6 mins not getting hotter than 230 degC. The components are from 2 batches 1 from dec 98 (highest failure rate) and 1 from oct 99. They have been stored on the shelf and may have been open for some time.
-Has anybody had this type of problem before?
-Are these ceramic packages susceptable to moisture from the air, and do they require baking before use if they have been open?
-Anybody have any other ideas?
Thanks in advance for any suggestions.
Craig
reply »