Electronics Forum | Mon Dec 13 05:43:27 EST 1999 | Wolfgang Busko
Hi Steve, 20 mil pitch shouldn�t be that problem nowadays. In your case bridging and poor wetting seem to go hand in hand. For the poor wetting try to eliminate it by using different paste (higher activated) and work on your profile. Coplanarity also
Electronics Forum | Mon Dec 13 21:11:53 EST 1999 | Curtis T.
Steve, I have done countless board profiling and oven reflow profiles. Here are the critical factors on you need to address. What is your board surface finish, if it is something like an OSP it will need a good amount of an active (aqueous) flux to
Electronics Forum | Thu Dec 16 16:46:47 EST 1999 | Mike Naddra
Steve , I use a general set of guidlines when developing reflow profiles: Ramp rate to 140 deg C - 50-60 seconds Time at preheat (140-160 deg C) - 90-120 sec Time above liquidous (183 deg C) - 45-90 sec Time at peak (215-225 deg C) - 9-12 sec peak t
Electronics Forum | Wed Sep 29 19:47:44 EDT 2021 | emeto
"For the lead free soldering of electronic assemblies, the inclusion of silver in the alloy results in better wetting compared to non-silver containing alloys and also allows for a broader process window. Silver also improves joint reliab
Electronics Forum | Thu Feb 27 16:23:37 EST 2020 | dwl
http://www.circuitnet.com/news/uploads/3/Comparing-Soldering-Results-of-ENIG-and-EPIG-Post-Steam-Exposure.pdf Years ago, I battled this problem. ENIG PCBs reflowed with active WS flux. We built one side, and then washed them because they were going
Electronics Forum | Wed Mar 15 00:44:39 EST 2006 | vicknesh28
Would i be able to judge how good is a reflow profile from the appearance of the flux residue? Often times i come across flux (not sure if residual) between a non-wet QFP lead and the reflowed solder paste on the pad (it's sandwiched between the bott
Electronics Forum | Wed Mar 02 05:14:07 EST 2005 | ABHI
Guys, Solder paste height worries all of us as we encounter the non wets after reflow. More so in fine pitch QFP's. The non wets are not always caused by solder paste height. Many other contributors. Even the pad geometry on te board can contribute t
Electronics Forum | Fri Sep 14 02:18:32 EDT 2001 | gsparka
Hi. After reflow soldering. There are lots of non wetting of leads. 71 b'd all are mounted resister,condensor,qfp,plcc,bga have got the defects so many. all defecs occured in the fine pitch ic. others are good. On some fine pitch pads not mou
Electronics Forum | Wed Oct 27 19:50:59 EDT 1999 | chris
Hi What is the possible cause of non-wetting of solder paste to the gold land pad. What we observed in the surface of the non-wet pad is an organic FM, and using FTIR we found out that it is a flux. It is possible that the cause of non-wetting is
Electronics Forum | Sun Nov 25 20:47:44 EST 2001 | Yngwie
knock!!!knock!!!Hellooo!!!!!!!
