Electronics Forum | Fri Oct 03 05:27:24 EDT 2003 | kanwal324
the puspose of solder mask is to prevent exposure of cu tracks to atmosphere. the lesser thickness can effect the performance of board but it only depends on its application. if you are making telecom board then its not good to use the board.
Electronics Forum | Wed Nov 17 10:03:29 EST 2010 | scottp
Instead of a minimum thickness, we require no exposed copper or SnCu intermetallic. We've been having a lot of trouble lately with suppliers of SN100 HASL boards giving us pads with very irregular solder deposits with areas of exposed intermetallic.
Electronics Forum | Wed Sep 10 12:56:09 EDT 2003 | davef
Intermetallic compounds [IMC]: * Form during the alloying process of some metals. In soldering these are Sn, Ni, Ag, Cu, Au. * Do not accept solder. * Increase in depth in logarithmic proportion to both time and temperature. [So during the solder
Electronics Forum | Wed Sep 03 07:43:13 EDT 2008 | davef
What do you mean by a "few micron thick"? IMC thickness pre-cycling (NEMI Lead-free) * Cu3Sn: 3um [118 uin] * Cu6Sn5: 1um [40 uin]
Electronics Forum | Wed Sep 03 16:59:13 EDT 2008 | glennster
At a former employer we required HASL thicknes to be a minimum of 0.75 micron (30 microinches), as measured at the thinnest point on any given pad. This would generally assure a minimum 1 year solderability shelf life. Usually when we saw a soldera
Electronics Forum | Wed Sep 03 19:54:23 EDT 2008 | vladig
Well, I'm not a sale person whatsoever. I'm a purely technical guy (even PhD :-)) who has been with the industry for quite a few years and I know very well what intermetallics means and how thck it should be for different board finishes and solders
Electronics Forum | Tue Mar 07 20:33:26 EST 2023 | SMTA-72027903
Hello We have recently started to work with press fit but we are finding problems to reach the specifications in terms of hole deformation and whiskers. Do someone have experience in key process parameters and PCB design specifications (PCB harness,
Electronics Forum | Thu May 25 08:47:39 EDT 2006 | inds
Patrick, we were seeing a good amount of Cu-dissolution with both SAC305 and SN100C.. couldn't figure out.. till our good old vendors told us that the Cu thickness in the barrel were not correct... but anyway have started some new work with SAC30
Electronics Forum | Mon Feb 21 11:22:21 EST 2000 | K. Ckak
Hi Kurt, I agree with Dave F. I had exact same problem with PBGA placement. We requested our PCB vendor to plug/tent via (button printing) after HASL with SR1000 which worked well in the long run. There are couple of failure modes associated wit
Electronics Forum | Mon Feb 21 11:22:21 EST 2000 | K. Ckak
Hi Kurt, I agree with Dave F. I had exact same problem with PBGA placement. We requested our PCB vendor to plug/tent via (button printing) after HASL with SR1000 which worked well in the long run. There are couple of failure modes associated wit
