Electronics Forum | Fri Mar 06 10:46:35 EST 2009 | davef
First, we agree with Loco that your QFP is nonwetting, rather than dewetting. Your sceen-shots look like ol' timey SnPb paste recipes. Turn-up the heaterometer dial. Second, on nitrogen: * We kinda think your O2 needs to be around 100ppm with 99.99%
Electronics Forum | Wed Mar 18 16:50:20 EDT 2009 | khowell
There are many users of SN100C in reflow. SN100C was originally introduced as a wave solder alloy which offered cost savings over SAC, no solder pot erosion, and high fluidity. Since it is eutectic, no plastic range, the joints have a smooth, shiny
Electronics Forum | Fri May 22 10:32:51 EDT 2009 | patrickbruneel
By law any forthcoming legislation in this area needs to be in compliance with http://www.nepa.gov/nepa/regs/nepa/nepaeqia.htm This requires an Environmental Impact Report (EIR) be prepared. Such a report has been done by the EPA in 2005 �Solders i
Electronics Forum | Wed Feb 17 12:16:17 EST 2010 | dcell_1t
Hi there: During the past weeks (let's say since beginning of the year) we've been experiencing some issues with shifted components. We verify for position before Reflow oven and the components are Ok, but they observe shifted after reflow. it occurs
Electronics Forum | Mon Mar 29 11:48:43 EDT 2010 | davef
SAC BGA In A Sn/Pb Reflow Process Conclusion: Area array components (ball grid arrays, chip scale packages, flip chip packages) with Pbfree solder sphere alloys should not be reflowed using a tin/lead reflow profile due to the resulting non-uniform s
Electronics Forum | Wed Jun 16 07:35:28 EDT 2010 | scottp
Rather than tent the thermal vias, we use a small annular ring of soldermask around them and only print paste in the areas between the vias. Any way you go you're going to have voids under QFNs, so we just try to make it repeatable so our designers
Electronics Forum | Wed Sep 21 17:53:19 EDT 2011 | action_101
I would like some input on reworking BGA's and the best method. I have reworked BGA's since 1998 using both micro stencils and just flux dipping the parts. I have reworked SN/PB and lead-free (AIM NC258) BGA's for the last 8 yrs. with just flux. I ha
Electronics Forum | Sun May 13 02:08:26 EDT 2012 | isd_jwendell
In testing 63/37 SnPb NC paste I have seen HUGE differences in performance. Have you tried a different paste? I prefer AIM (NC257-2), they have performed well in each round of testing. My observations regarding mixing old and new paste: The paste ha
Electronics Forum | Wed Aug 06 14:49:06 EDT 2014 | dyoungquist
Sn62Pb36Ag2 has a higher liquidus point of 189C as compared to Sn63Pb37 at 183C. You may need to slightly adjust your oven profiles to use it compared to SnPb. We have had good solder-ability and reliability with it in our IPC Class II products. A
Electronics Forum | Fri May 22 12:42:43 EDT 2015 | deanm
Sr. Tech, you are right in that there is no verification of the profile. We are a Class 3 high mix OEM. We have visual inspection after SMT. We have not seen problems with wetting, grainy solder, cold solder, charred boards, etc. that would indicate
