Electronics Forum | Thu Sep 06 10:55:37 EDT 2001 | davef
saturation occurs at ppm levels. Remember, IPA is extremely flammable and its bulk use makes the plant liable to all sorts of quite repressive safety rules/regulations and so on. Ignoring these rules exposes the owner to fines and possible plant cl
Electronics Forum | Thu Sep 06 10:58:54 EDT 2001 | Steve
If I had to deal with this problem, I would switch to water soluble paste. It is a much more cost effective solution.
Electronics Forum | Fri Sep 07 21:43:40 EDT 2001 | mugen
Hi, We use IPA and Prozone, if IPA is so drastically detrimental, to the pcba's.....what suggested alternative, can you please recommend, as IPA replacement? Thanks.
Electronics Forum | Thu Jul 07 07:18:50 EDT 2005 | davef
Sounds like you need to turn-up the dial of your oven. Solderabilty protection finishes on components are changing, whether it makes sense or not.
Electronics Forum | Thu Jul 07 18:03:27 EDT 2005 | russ
Sarag, FYI tombstoning is a functional failure. Tombstoning is where one end of the component is not soldered and is in the air above the board/solderjoint surface. You may be thinking of billboarding (part on its side with both ends soldered down)
Electronics Forum | Mon Jul 25 18:54:10 EDT 2005 | Brian
Exactly. We bring the paste apertures closer together, so that the part sits more in the center of the paste. As a CM, our customers do not always accept our recommended design changes, so we use this method to reduce our tombstoning if the pad geo
Electronics Forum | Thu Jul 14 13:05:18 EDT 2005 | Bman
Considering all the constraints you are faced with, I would try changing the apatures for that part on the stencil. It seems as though a no-clean "homeplate" appature would put less paste on the board. Less paste means less flux, and it might be en
Electronics Forum | Fri Jul 15 13:16:08 EDT 2005 | Brian
We have seen this problem in the past and had to deal with similar customer constraints. It's not the flux causing the wetting, but the placement and pad geometries as some have mentioned. To reduce or eliminate the problem, we have changed the ape
Electronics Forum | Thu Jul 07 04:34:19 EDT 2005 | Lloyd
This problem exists at a very low level but happens on all our discrete components, all our products and in two plants. Between the PCB land and the component termination there is a barrier of flux residue, this actually lifts the component slightly
Electronics Forum | Thu Jul 14 16:12:22 EDT 2005 | russ
Lloyd, could you get us a pic from the side? It looks to me as if the pads may be too small or far apart, but I can't tell. We normally use a 35 x 35 pad size on .07 centers when we have the luxury of designing them that is.
