Vacuum Drying Electronics - for repairs

[@handpiece]

I would like to come one day to see your workshop and all your equipment and enjoy, may you win

[@BjornV78]

Love these experiments. A few other experiments you can do, is to take a pcb that is lying arround and weigh it before and after some vacuum, too see if it also removes moisture that was trapped in the pcb by just lying arround. Another experiment with vacuum is to use some electrolytic capacitors and weigh them before and after the vacuum treatment, because electrolytic are "wet" capacitors due the Dielectric contents, my theory is that these can loose there properties if the Dielectric "boils" out due the vacuum. An ESR and capacity test before and after the vacuum can confirm this or not. Also some materials like Nylon can absorb moisture from the surrounding air.

[@craigs5212]

Wash in warm DI water, blow off the majority of the water then wash in dry IPA (99%) and finally dry with warm air. You still need to pay attention to components that are not washable in any solvent, like a fiber optic connector or some pressure transducers.

[@pwest3732]

Yup, I have dabbled with vacuuming boards to dry them as well. One suggestion would be a laboratory type hot plate. Capable of fine adjustment from room temp to hell hot. Set it upwards of 100°C. Back in my previous existence building boards we would use SN63 or SAC305 solder paste and would build on these hotplates. (Or better yet use a reflow oven.) All that to say, 100°C wouldn't harm the boards and the heat would let moisture evaporate even faster. If the bottom of the chamber would sit flat on a hotplate, I know you would get a better result. And using your aluminum 80/20 heatsink is a good idea too. Or a chunk of copper, although expensive. To continue, after reflowing the solder, we would wash in an ultrasonic cleaner set as high as it would go. Pulling the board out after cleaning, it would rid itself of any moisture due to the heat soak it went thru during cleaning. Heat was the key to losing that moisture. The only thing we couldn't ultrasonically clean was anything we had ribbon or wire bonded. Or had free air coil inductors either factory made or made by hand. Or components that had an internal battery. But again, heat was the key to getting rid of moisture. The vacuum helps and have vacuum bagged items in the oven too. You have a great idea here and could save someone in a pinch.

[@CebtechEngineering]

What a great idea !

[@Backcountry_Bodger]

Just thinking aloud here, but wouldn't the condensation cause the pump to fail prematurely, all that moisture can't be good for the life of the pumps internals can it?

[@BetterBiomedChannel]

@@Backcountry_Bodger the oil is changed regularly

[@Savant218]

Why waste the time ? I can take a board full of rust and clean it in my ultrasonic tank in 4 minutes - then rinse it under the faucet with tap water and then squirt 99% IPA on it for a minute then place in my preheated conv oven (110F) for 2 mins plug er in and test !

[@BetterBiomedChannel]

@@Savant218 that will not dry everything

[@coldfinger459sub0]

What looks like water vapor or steam coming out of the vacuum pump is actually oil mist. The first removal of the air under high velocity because of the mass and the high velocity of the impellers on the surface of the rotor blades the film of oil comes out with the air.. Something was wrong with your vacuum set up either you have a vacuum leak somewhere or something’s wrong with the pump because you should’ve been down to around 7000 8000 µm something you cannot read on an analog gauge in less than five minutes. Throw a micron gauge I recommend the Accu tools BluVac Pro because you can also computer data log it And you can prove all the moisture is removed after you perform a vacuum decay . After you shut off the vacuum, the vacuum should not go above 200 µm to 500 µm. If you still have moisture when you shut off the vacuum and perform your vacuum decay vacuum will keep increasing to around 3000 or 3400 µm and then stop in plateau. This tells you you still have moisture in micro pores, possibly underneath the plastic film of capacitors, etc.. You just pull a longer vacuum until it can hold after you turn off the vacuum to below 500 or 200 µm. And of course, in real life, we would use the ionized water or reverse osmosis water because of the dissolved salts in regular tapwater from the ground, and the distributing piping leeches, calcium, magnesium, iron and other dissolve salts when you evaporate the water, it leaves a conductive coating at the microscopic level of salts.