On 18 December 2014 at 21:32, Richard Prosser wrote: > Does the same apply to assemblies ultrrasonically welded into a box I > wonder? If so, this post could have saved us a bit of future strife - > Thanks > Yes and or no until you open the box (and may depend on whether you like or dislike cats) .. Examining the box performance remotely is liable to affect the result. __________________ More seriously - I was only passing on Jesse's comments, but you can imagine that the amount of ultrasonic energy reaching objects inside a box would vary immensely due to a wide range of parameters (overall dimensions, power level, resonances, mountings, substrate, box materials, box dimensions and resonant modes and and and ...) and that there would be cases where the answer was "often" and others where it was "essentially never". Knowing that the answer could sometimes be other than the latter is valuable in its own right. eg if open ultrasonic cleaning essentially always destroyed a given MEMS device it would almost certainly be possible to produce a housing such that, by design, ultrasonic sealing of the housing almost always destroyed the MEMs device. If you can do it by design then Murphy can too. Equally, it would be possible to produce a housing by design where destruction almost never occurred. Murphy will work on "optimising" almost-never. Russell --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .