Electronics Forum | Thu Feb 21 17:19:08 EST 2008 | davemn
if you are not using them for test points or want them filled with solder for current carrying capability then tent them puppies. i was able to move our company away from exposed vias many years ago and this eliminated lots of hairline shorts between
Electronics Forum | Tue Apr 08 15:27:33 EDT 2008 | arminski
hi experts, need more info on what's happening with the LPI Solder Mask on an FR4 PCB during reflow of both Leaded and Lead Free Process? Do they become soft as well while exposed to the extreme temperatures? regards,
Electronics Forum | Thu Jul 24 13:12:41 EDT 2008 | dphilbrick
I seriously doubt it. It is extremely thin and the gold's only real purpose in life is protect the nickel underneath from oxidizing. Once you wear that very thin gold off you will have exposed, oxidized, nickel and loss of conductivity.
Electronics Forum | Mon Aug 25 10:36:05 EDT 2008 | davef
Yes, it's peculiar that the layout of this board is so disorganized * Pads are not round, uniform, or the same size * Exposed traces have different thickness
Electronics Forum | Tue Sep 02 12:43:12 EDT 2008 | stepheniii
That could lead to oxidation of the leads and worsen solderability. It's much better to make sure the components are handled properly and not exposed to moisture. The reason for baking is moisture in the body not in the leads. Why is no one suggest
Electronics Forum | Wed Sep 03 12:29:47 EDT 2008 | omid_juve
That could lead to oxidation of the leads and > worsen solderability. It's much better to make > sure the components are handled properly and not > exposed to moisture. > > The reason for baking is > moisture in the body not in the leads. > > W
Electronics Forum | Tue Jul 07 08:42:49 EDT 2009 | ewchong
kpm, you are probably right. under magnification those two pads show some exposed copper which means that they were contaminated or had insufficient solder paste before reflow.
Electronics Forum | Fri Oct 30 08:24:12 EDT 2009 | rajeshwara
thnx davef & all With the help of all at last i solved the problem , The vias are not caped from bottom , so solder paste draining through the via to the floor which creates voids between IC ground pad and e-pad. Tnhx all again
Electronics Forum | Tue May 11 09:44:48 EDT 2010 | dyoungquist
Lower humidity: Pros: Helps with mositure sentative devices. Cons: 1)Paste exposed to the dry air during your porcess will dry out quicker. 2) Drier air promotes more ESD issues, i.e. more electrostatic generation.
Electronics Forum | Tue Aug 03 17:13:41 EDT 2010 | bradlanger
Craig, If it is LF Hasl it sounds like it applied too thin exposing the intermetallic layer wich is not solderable. We call out a minimum thickness of 80 microinches and have good results. We have had shops in the past that did not control the Hasl
