Hi,
I had a question regarding the rf measurements I am doing on some mems switches.
1)Does the chuck of the probe-station need to be grounded while doing the
measurements?
I get different results when the chuck is grounded and not-grounded.The results
seem to be better when the chuck is not grounded.
I am using coplanar probes and have an rf signal with a dc bias.
2)Also, what I have obserevd is that, grounding the chunk momentarily, when
placing the probes onto the bond pads, eliminates a slight switch movement I
have, when the same is not done.
Also, after the bias volatge is removed, the switch comes back up immediately if
I ground the chuck and lift the probes.If the chuck is not grounded, the switch
stays stuck for a longer time before coming back to orignal posistion.

I believe it's not a stiction problem, but more of a charge build-up and/or
grounding problem.

I would appreciate any suggestions.

Thanks in advance.




Kaustubh Bhate
Transducers Group