Electronics Forum | Thu Apr 20 03:50:35 EDT 2017 | cromaclear
To overcome the dewetting issues of the past, a number of techniques have been used such as alternating directions on the wetted nozzle; this helps to avoid the solder biasing to one side causing the other side to oxidize and de-wet. Another method o
Electronics Forum | Wed Jul 26 11:56:40 EDT 2017 | rgduval
Ah...the joys of subjective analysis! At a glance, these pictures look fine to me. Other than the IC's, which you've indicated were masked, and, maybe R12 in the last picture and CC1384 in the first image, coating looks uniform and well distributed
Electronics Forum | Mon Jul 31 14:06:40 EDT 2017 | rgduval
Ain't that the truth!! In a previous life, we did a (somewhat brief) cost analysis of class three rework being performed on class two boards. When we realized how much time/money we were losing due to unnecessary rework, we decided to start taking
Electronics Forum | Thu Feb 01 07:41:01 EST 2018 | dontfeedphils
Interesting, never heard of using wax as a coating mask. Not sure how well the AR coating would hold up to a hot alkaline wash (unless you have experience with it), but that stuff usually starts to flake off/de-wet if you just look at it wrong. I'm
Electronics Forum | Fri Apr 25 11:38:22 EDT 2008 | vortex337
Our company has run into an issue with de-wetting of lead free components. Our profile is dead on with paste manufacturers specs. We have had this issue with both gold immersed, and hot air leveled boards. We have tried three different solder paste m
Electronics Forum | Tue Jul 25 16:08:52 EDT 2017 | dontfeedphils
I'm currently working on bringing a manual coating process/workcenter online and my QA team is giving me some grief. For background, we're using Humiseal 1B31 thinned with thinner 521, mixed at 1:1 by volume. Spraying through a Binks HVLP with 10 P
Electronics Forum | Mon Mar 30 12:55:16 EST 1998 | Justin Medernach
| Hi, | We have encountered de-wetting issues with gold plated components( SMT LEDs ). | The problem comes and go and we yet to locate the root cause ( process, component or solder paste etc ). | The rest of the components on the boards are not havi
Electronics Forum | Thu Mar 06 11:36:37 EST 2003 | O' Connor
Hi, I'm experiencing a problem on a standard part made many times before -Ni/Au finish PCB, Reflow 100% SMD parts. After reflow the gold on the pads does not fully fuse with the solder paste it remains intact on the extremities of the pads, it seems
Electronics Forum | Thu Mar 06 11:50:22 EST 2003 | John O'Donnell
Greetings Sir, Although I am not qualified to address the issue in detail, I do know first hand that you can obtain very comprehensive and accurate solutions and explanations from George Westby, Director, Universal Instruments Advanced Technology and
Electronics Forum | Fri Mar 07 05:36:21 EST 2003 | O' Connor
Hi Again, In answer to DaveF - Yes solder is fine where the solder paste is deposited , but the part of the pad visible after pasting is still visible after reflow. Previously the solder paste & all the gold diffused & flowed giving a complete silve