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I'm working on a project that employs a microcontroller in an 80-85°F environment with quite a bit of humidity. It's going to be placed directly next to an array of fish tanks. Obviously, the water can damage the device if water is spilled on it but this shouldn't happen.

Would the device be ok if operating in those conditions for days at a time? I've been considering designing an enclosure with a fan(the microcontroller already has a heatsink on the CPU) but are there any other considerations such as rust that I should keep in mind? Thanks for your answers!

jpxrc
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Conformally coat your PCB. Conformal coating, which you can for instance buy as a spray-on substance (Plastik 70 is a popular choice that is stocked with most electronics distributors), creates a moisture, dust and grime-resistant coating over your entire PCB. The 'conformal' in the name means that it is especially engineered to form a continuous coat without holes or voids.

user36129
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  • This is an interesting alternative. Would I only coat the exposed pins? When I looked up conformally coating it showed that the whole device was coated. I'm wondering if this will adversely effect heat dissipation... – jpxrc Jul 16 '14 at 21:29
  • You coat everything; the entire PCB. That's the 'way to do things' when dealing with direct moisture or condensing moisture - or harsh environments in general. Yes, it will affect power dissipation. If you're worried about parts getting too hot, heatsink them. – user36129 Jul 16 '14 at 21:56
  • When applying conformal coat, you have to mask off the areas you'll want access to during final assembly. This includes connectors, solder points, and contact areas for heatsinks. – WhatRoughBeast Jul 16 '14 at 22:42