Electronics Forum | Mon Mar 19 10:52:32 EDT 2007 | ed_faranda
Really, you need to do a DOE on with your paste to figure that out.
Electronics Forum | Thu Mar 15 09:25:32 EDT 2007 | jseagle
It will also depend on if the paste is OA (water soluble) or No-Clean. I believe you can leave No-Clean out longer because it absorbs moisture slower than OA. As always check with the paste manufacturer to see what they say. It should also be on t
Electronics Forum | Fri Mar 16 02:20:09 EDT 2007 | Wayne
Have to check with paste manufacturer. paste on the stencil should be at least 12 hours paste on the board before mounting should be at least 4 hours.
Electronics Forum | Fri Mar 16 07:10:53 EDT 2007 | davef
1 Print paste on a bare board or laminate. 2 Place components in the paste. 3 Gently invert and support the board above a table. 4 At one hour intervals, record the number of components that have fallen from the board.
Electronics Forum | Mon Mar 19 10:35:44 EDT 2007 | dyoungquist
We use a no-clean lead free paste with our manufacturing floor temp 70-75F and humidity 20%-30%. We have found that if the time from pasting a board until it goes into our reflow oven is less than 4 hours we have no problems. If it is greater than
Electronics Forum | Tue Apr 10 13:39:07 EDT 2007 | mumtaz
Stop asking this.
Electronics Forum | Mon Mar 19 14:24:30 EDT 2007 | jdengler
I have been involved with the evaluation of close to a dozen pastes from 5 manufactures. I never found one that would rest on a board for anything close to 24 hrs and still have acceptable performance. Jerry
Electronics Forum | Tue Mar 20 03:48:06 EDT 2007 | chrissieneale
Already figured i would do that if it came to it - still planning my approach, which will hopefully eliminate this whole 'waiting after pasting' nonsense anyway. Suggestions very welcome though, as it may well get to the test and see stage! Cheers
Electronics Forum | Thu Mar 29 08:58:06 EDT 2007 | chrissieneale
Started measuring rework last week - on some of the boards we are looking at a shocking 20% right first time yield. The paste thing has to be fixed as it's being left more than four hours. Thanks for all the comments - Will let everyone know the re
Electronics Forum | Mon Mar 19 06:47:36 EDT 2007 | chrissieneale
After a little investigation (with my eyes closed and fingers crossed) how about up to 24 hours?! ?! I think i might have found one of the root causes of my oooooodles of rework.
