Electronics Forum | Tue Jul 30 17:47:50 EDT 2002 | davef
Dewetting: Solder does not adhere to lead or land, caused by: * Poor solderability of lands. * Poor solderability of leads. * Solder paste integrity. * Lead plating integrity. Need more information, please: * What is dewetting [ie, component, pad, e
Electronics Forum | Tue Jul 30 08:37:39 EDT 2002 | davef
When you talk about 'poor wetting', 'dewett', 'no wets', etc.; are you seeing solder pulling back or away from the pad? Please describe the condition. Dewetting. The condition in the solder joint in which the liquid solder has not adhered intimate
Electronics Forum | Mon May 10 20:46:25 EDT 2004 | davef
The three basic methods you can use to restore solderability on components are: * Highly active fluxes in a retinning operation. * Surface stripping chemistry and then a standard retinning operation. * Electrochemical conversion chemistry and then a
Electronics Forum | Mon May 12 17:59:55 EDT 2008 | rgduval
We're currently experiencing a spate of solder not wetting to pads of PCBs, and it's becoming more aggravating on a daily basis. At this point, we're running out of ideas. I've searched the Fine Archives for information, and, so far, haven't found
Electronics Forum | Tue May 13 08:26:29 EDT 2008 | davef
First, on your reflow temperature comment: The 183*C focus for reflow recipes for tin-lead solder is a falicy. If you held a recipe for tin-lead solder at 183*C peak, it would never reflow. Recipes for tin-lead solder need to be at liquidus plus 20*C
Electronics Forum | Wed May 18 14:58:05 EDT 2005 | splice
Hi, I am having some PTH non wetting issues. Setup and chronology of events is explained: Set Up; Part: 1 MM pitch connector 378 pins Solder: Kester Ultra Pure 63/37 solder Pot; 250 C pre heat; Peak 94C top side Flux: Qualitek 775, Fluxer: foam T
Electronics Forum | Wed Nov 06 19:03:33 EST 2002 | broncos
If you are certain that reflow process is good, I would suggest starting checking the following: 1. Check to see if leads / pads are contaminated or oxidized. However, this usually results poor solder quality throughout the board. 2. Check the amou
Electronics Forum | Fri Apr 29 14:16:16 EDT 2011 | ppcbs
Below is the long explanation. This defect is most commonly found with BGA components, but can arrise with all components. I see it happening more now with lead free boards that are being assembled with a no clean flux. Best short term remedy is t
Electronics Forum | Tue Sep 28 17:56:02 EDT 2004 | Vee Sar
Adam, I would first check hole to lead sizes on the components that you are having hole fill issues with to see that the spacing is withing spec. Second, check for oxides on lead tips, and contaminated leads that cause poor wetting and insufficient
Electronics Forum | Thu Oct 28 09:25:35 EDT 1999 | Dave F
Chris: Typical non-wetting causes are: * Poorly controlled soldering process * Incorrect material * Surface contamination * Insufficient preheat * Misapplied solder mask * Shadowing Without intending to insult you, all of the causes of non-w
