Need to identify part

[jtronix]

Hii,

Please see image ..

this look like black rubber which was mounted on mental body downside it was placed on smps output capacitor pin (solder side).
black part was placed between smps output capacitor and metal body and metal body was finally connect with chassis ground.

can anyone identify which material is this and why this is placed like this??

[SeanB]

Most likely a vibration damper and spacer, so that the board flexing due to either applied force or vibration does not short the capacitor pins, and thus the power supply, to the chassis ground. Likely it is a neoprene rubber synthetic foam, typically with an adhesive layer on one or both sides. Very common as sound samping material on panels, and in cars inside the doors and body for vibration damping.

[jtronix]

see more picture to clear scenario.

in this case capacitor shorting is not possible at all because distance from chassis and board is quite enough..

does this is used for emi/emc  noise suppression

[SeanB]

For acoustic noise reduction yes, and to keep the case from flexing to touch the board. Not for EMC as it would have to be a conductive foam to do that. They must have had an earlier version shorting out from either vibration of heat flexing the board or case at that point, so this was added to ensure it was not going to short out. As there is a conformal coat there it would not be any conductive foam.

[jtronix]

do you have any datasheet??

how acoustic noise is relate to smps circuit??

this is smps boost converter which convert 24VDC to 90 VDC.

[jtronix]

awaiting for experts comment