Ceramic case resonators falling to pieces after reflow soldering.

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We are reflowing ceramic resonators and are finding their t... - Aug 30, 2000 by Craig

Hello Craig Are code dates other than these two coming apar... - Aug 30, 2000 by John Thorup

Craig

#3136

Ceramic case resonators falling to pieces after reflow soldering. | 30 August, 2000

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

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John Thorup

#3137

Re: Ceramic case resonators falling to pieces after reflow soldering. | 30 August, 2000

Hello Craig Are code dates other than these two coming apart or do they stay together? If other dates stay together you should get together with RFM. Did the process work before and and the defects just start happening? These are pictured on the RFM website as dark bodied. Since you have an IR oven they could be getting quite a bit hotter than other components. There is not a lot of wiggle room between 230 and 250. Have you monitored the temp on the resonator itself? John Thorup

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