Quote:
Originally Posted by Bassnut
At risk perhaps,but I have often liquid cooled my st10xme with iced water till it was dripping weT in hi humidity without a problem at all.
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That is asking for trouble and here's why. When the PCB gets wet the solder on all those surface mount chips can get wet and if it does, it can and will cause dendrite growth. Those are little "whiskers" that grow like spikes from the solder. Eventually they end up shorting solder balls or traces together.....
http://www.narrowbandimaging.com/inc...-corrosion.jpg
The failure can happen rapidly in the presence of ionic contaminants or it can take some time but eventually that's the failure mode. so your camera may work OK now but eventually it will fail. I have seen three ST10XMEs that first had the -X guider output fail due to this dendrite growth. One was mine and it happened because I too had been using chilled water and my camera got soaking wet twice. Mine failed about 6 months later. Another happened to a fellow that lives on the Florida Gulf Coast and is in a very humid environment and dew condensed on the camera (he lives near salt water in a humid environment but he was not using water). He was advised by SBIG to open it up occasionally and use a toothbrush to scrub the PCB
Another failed for a fellow in Tennessee that was in a very humid scenario using chilled water
One thing that can be done is for the manufacturers to use conformal coatings on the PCBs once they are assembled. That is how marine electronics such as VHF radios and Radar systems are made robust.
I've been complaining that none of the makers do that. For the money we spend on this stuff, they could afford a few bucks to conformally coat the PCBs but no one does....
the Proline cameras have the electronics protected from the elements. That's a good thing. The Microline does not have environmentally protected electronics.
Obviously the ST10 does not either. Not sure about other brands
The use of fine pitch surface mount components and ball grid arrays only aggravates the problem. Unfortunately my industry has switched nearly exclusively to such packaging technology. People want tiny Iphones and notebook PCs so miniaturized components is the way it is done.
The area array BGAs (ball grid arrays) are particularly bad because all of the solder connections are below the chip's package and cannot be visually inspected.... you can use underfill to prevent moisture from getting in but that makes rework difficult
here's a nice reference that speaks to many other failure modes including what I just described
http://www.narrowbandimaging.com/inc...d-Only__01.pdf
look at page 7 for the moisture induced dendrites. Simply getting the PCB wet can cause growth but do so with power applied and you have it accelerated
At the end of the day you are better off buying a camera that is designed to cool well. SBIGs and QSIs do not have that property.