Electronics Forum | Mon Aug 11 10:35:32 EDT 2008 | realchunks
What does your top side wetting look like? This is a perfect case where top side wetting will tell you when you have a good joint. Without seeingor knowing your process, I would suggest either more pre-heat or longer dwell in the solder. Either on
Electronics Forum | Tue Aug 17 14:34:27 EDT 2010 | davef
Comments are: * Too much paste ... reduce it more. * Do not let a traces run between small discrete pads or the heat of reflow will pull a ball to the trace, we can repeat this. * Change the placement height on chip parts to reduce solder spread / mu
Electronics Forum | Mon May 21 09:04:15 EDT 2012 | cbeneat
We've had the same issue on our Panasonic CM machines with Cree XP type LEDs. Count on tools makes a urethane tip nozzle that we are using which eliminates the sticking, our concern with these is durability. Nozzle supply company makes a steel Teflo
Electronics Forum | Sat Sep 16 15:50:48 EDT 2017 | ctran
An assembly with this improperly solder joints will have functional issues. We have encountered this many times with memory modules failures,RMA units. Reflow always solved the problem (in our many cases). Dwelling time may be the key to solve this.
Electronics Forum | Thu Feb 15 23:52:31 EST 2001 | Dreamsniper
Hey guys, I ran a couple of profile in our wave solder machine using wave optimizer and this is what i got: Parallelism = 0.0 Immersion Depth = 2.1mm to 2.4mm with varying immersion time from 1.1 sec to 3.1 secs. Contact Length = between 5.0 to 6.0
Electronics Forum | Tue Jul 30 17:45:56 EDT 2002 | davef
What's this 'metalic coating on both sides'? Is that like a 'two-sided board'? I expect that your 200�F is the primary side temperature just prior to entering the wave. If not, you need more juice [depending on your flux and all that]. [Some mode
Electronics Forum | Wed Jun 18 19:26:39 EDT 2003 | gregoryyork
Rules of thumb :- 1. Never over flux - not necessary and waste's money. Never top flux neither 2. Top Board temp. around 70C - 105C or there about's pending what laminate you use. Obviously the more flux you apply the higher heat required/denser PC
Electronics Forum | Tue Nov 21 19:23:15 EST 2006 | greg york
Had exactly the same problem the other week. Baked some boards did improve slightly but not convincingly. Washed bare PCb and found excessive HASL fluids left on board from improper rinsing and problem disapeared. Baking HASL fluid out is impossible
Electronics Forum | Tue Sep 11 19:04:28 EDT 2007 | hakerem
Hi Shrek - Not sure why you think adjusting dwell time and preheats is a sales pitch, but I do appreciate your candor. These are proven, widely used techniques for attacking, eliminating and preventing the recurrence of blowholes. Since it is so ea
Electronics Forum | Fri May 23 18:55:20 EDT 2008 | gregoryyork
This is one of the biggest mistakes with the Lead Free process. We have all listened to the 'industry experts' and followed their advice and unfortunately got it wrong. Keep the dwell times (dependant on alloy selection) the same as Leaded so you are
