Carbon Contamination

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Hi We are mounting an microphone device (SMT package) onto ... - Nov 06, 2023 by Adam

We are mounting an microphone device (SMT package) onto a PC... - Nov 07, 2023 by MagyarT

Adam

#90197

Carbon Contamination | 6 November, 2023

We are mounting an microphone device (SMT package) onto a PCB which has an ENIG finish and, observed some contamination on the underside of the device, post reflow. The SEM analysis shows that the contamination has a high level of Carbon. Where could this be coming from ?

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MagyarT

#90204

Carbon Contamination | 7 November, 2023

We are mounting an microphone device (SMT package) onto a PCB - how? Surface mount line or hand soldering?

Contamination can only come from the solder paste, solder wire, flux, or burning the component/PCB assembly during hand soldering. Unless the component was contaminated prior to assembly.

Would look at the datasheet of the part, and check the reflow/soldering temperature against what temperature was used.

Only rosin type fluxes would contain carbon or carbon-derived products.

Any pictures added, would help everyone to understand your situation better.

Regards, Tom

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