Post soldering cleaning - Page 1
Forum section: electronics / beginners

author: Noidzoid
author_rank: Regular Contributor
timestamp: July 08, 2018, 05:32:50 pm
content: I wish to clean a board after soldering. I saw on eev on YouTube a toothbrush type brush being used by Dave. I understand an antistatic brush needs to be used and was just completing putting an order together and thought I would just add one of those. What a shock I had when seeing that a single brush was approximately £10!!!!My question is.....can a normal toothbrush be used IF I use an earth strap attached to it to prevent static?

author: JS
author_rank: Frequent Contributor
timestamp: July 08, 2018, 05:42:44 pm
content: I use a normal toothbrush without straping it to anything, not recommended but never had a problem. Note that here humidity is always very high so ESD isn't a concern, we have other problems but not ESD.JS

author: helius
author_rank: Super Contributor
timestamp: July 08, 2018, 05:52:31 pm
content: ESD brushes may be required for process-certified applications, but for most uses a wood brush with animal hairs is sufficiently dissipative. They come in a range of shapes between $2 and $10 in single quantities. Remember that while the brush and board are wet with solvent, triboelectric charge generation is inhibited. It would not be a good idea to use them in a dry state.

author: wraper
author_rank: Unknown
timestamp: July 08, 2018, 06:20:09 pm
content: You could look ar TME. There are some cheap ESD brushes starting from like 2 quid. Shipping cost won't be justified if you order only that, though.

author: eKretz
author_rank: Frequent Contributor
timestamp: July 08, 2018, 10:19:55 pm
content: I have always just used a toothbrush with some IPA. Ben doing it that way for many years. Never had a component fail from cleaning with that yet.

author: exit_failure
author_rank: Regular Contributor
timestamp: July 09, 2018, 01:37:09 am
content: Antistatic brushes are about 1€ if you order them from China via ebay/aliexpress. Depending on how much you would use them they might be perfectly alright for what you're doing.

author: wraper
author_rank: Unknown
timestamp: July 09, 2018, 02:06:51 am
content: Quote from: exit_failure on July 09, 2018, 01:37:09 amThey might be perfectly non ESD safe as well, though. Just black plastic.

author: JS
author_rank: Frequent Contributor
timestamp: July 09, 2018, 02:09:39 am
content: It drives me crazy how non insulator stuff is hard to find and expensive but when you need a good dielectric ahaaa! Expensive and hard to find again....JS

author: exit_failure
author_rank: Regular Contributor
timestamp: July 09, 2018, 02:20:08 am
content: Quote from: wraper on July 09, 2018, 02:06:51 amESD safe brushes are usually made out of carbon fibre which is electrically conductive. You should be able to test that with a multimeter. Worst case: you lose a buck.Another idea (that I havenottested myself) would be buying a piece of ESD safe foam (the stuff ICs are (should be) shipped on). Cut it into small pieces and use it as a sponge. Just make sure you wear gloves when doing so since isopropyl alcohol is lipophilic (a solvent for fat) and can dry out your skin significantly.

author: boffin
author_rank: Unknown
timestamp: July 09, 2018, 02:59:25 am
content: A spritz bottle w/ 50/50 nail polish remover and isopropyl, let it sit 10-20 seconds, then hit it with an old tooth brush(which were invented in the Outback otherwise if would have been a teeth brush)then repeat with pure isopropyl.

author: Sudo_apt-get_install_yum
author_rank: Regular Contributor
timestamp: July 09, 2018, 06:01:51 am
content: I have an unlimited supply of antistatic brushes through work; unless you’re working on super sensitive electronics it doesn’t really make much difference.Just buy an antistatic brush and keep it around in case, its only 10€

author: tooki
author_rank: Super Contributor
timestamp: July 09, 2018, 09:25:26 am
content: Just a reminder that alcohol isnotstatic dissipative. There have been industrial explosions caused by the static charge in alcohol itself, caused by the motion of the alcohol flowing. So for anything delicate, I wouldn’t rely on alcohol to avoid static...

author: wraper
author_rank: Unknown
timestamp: July 09, 2018, 10:07:21 am
content: Quote from: exit_failure on July 09, 2018, 02:20:08 amThey are made of carbon filled plastic, not carbon fiber.

author: exit_failure
author_rank: Regular Contributor
timestamp: July 09, 2018, 10:27:00 am
content: Quote from: wraper on July 09, 2018, 10:07:21 amYou're absolutely right but for them to work properly they still need to be conductive.

author: sleemanj
author_rank: Super Contributor
timestamp: July 09, 2018, 11:54:59 am
content: Quote from: exit_failure on July 09, 2018, 02:20:08 amI have bought ESD brushes from Aliexpress before, the first lot I bought at least had conductive handles in the range 5-10M, the second lot a couple years later appear 100% identical but do not show any conductivity at all, so they went in the dubious junk drawer, not being able to readily test them to see if they are just dissipative.Now there are higher count meters readily available for everybody it's easy to test quite high resistances, but if you only have a 2000 count meter or whatever a simple trick is to use an LED and a (preferably current limited) supply capable of 30v or more, wind the voltage all the way up and use the handle of the brush as a resistor in series with the LED, even though some number of meg ohms a dim glow can be seen in the dark.Not that it necessarily is of any real concern in a hobby situation, but if you're buying an ESD brush from China then you might as well check to see if it actually exhibits any property that is consistent with being an ESD brush.