Ultrasonic cleaning and xtal ?

[cgroen]

I have a ultrasonic cleaner/bath and using Chemtronics fluid. I have heard some comments that cleaning with ultrasonic can have a negative impact on crystals and such?
Any experience regarding this ?

[sstepane]

Hi,

Have been cleaning boards with xtal (12mhz, rtc xtals) - seen no issues. There's a rumor that the xtal could be damaged if its frequency is close/same as ultrasonic cleaner (20-42kHz), but not sure about it and, afterwards, where do you find such an xtal?

[Gribo]

Low power watch crystals are in that range (32768Hz).

[metrologist]

I think the concern is with any mode that can resonate and loosen bonds.

[cgroen]

Thanks for replies!
Have any here actually seen this, or have you only heard about it ?

[ataradov]

Only anecdotal evidence. I've been cleaning boards with 32 kHz Xtals for some time and I have never seen a failure. But this obviously does not mean that there was no subtle damage that may become evident later.

I have never seen actual evidence of the damage actually provably happening.

[Gribo]

I had failure (component out of spec) for a 26MHz crystal. Spec was 20ppm initial accuracy over standard temperature range (-10 to 50C), assembled product had 40ppm. We traced it to the ultra sonic cleaning process. Moved to standard washing, and everything was alright.