Electronics Forum | Thu Nov 15 09:29:03 EST 2007 | jaimebc
Just to add to the subject, we experienced insufficient solder on our QFN's at our prototype level. To correct it, we went to a 5 mil stencil, 20% reduction on QFN pertures and used QFN's with solder bumps on the pads. We had great results using thi
Electronics Forum | Wed Jul 27 03:50:51 EDT 2005 | aj
Crishan, I am not familiar with the machine you mentioned. Do you use selective solder pallets through a wave process or is the machine a selective soldering machine (ie. where the board is moved to the solder fountain) No matter what the process
Electronics Forum | Thu Jun 25 11:11:13 EDT 2009 | bruna
Hello, I want to hear some experience about selective soldering for PCB using nozzle plate and screens Do you have solder defects? bridges and insufficient soldering? How do you combat that? and about the screens you have good quality? What is the f
Electronics Forum | Fri Dec 01 07:46:41 EST 2006 | davef
Bridging Causes: * Insufficient flux * Excessive pre-heat * High conveyor speed * Solder contamination
Electronics Forum | Mon Apr 16 12:59:51 EDT 2001 | Mike R
If you will place a temperature strip on the board during wave soldering process you will get a max of 210 F or 98.8 C which is normal on the standard wave temperature. The problem on the 10% solder on the TH via hole can be caused by insufficient fl
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 | Thu May 05 09:50:29 EDT 2005 | patrickbruneel
Hi Hannu, You just gave a very realistic and practical view of the lead-free dilemma. The main reason that your coil coating doesn't get removed is because of the inability of lead free alloys to wet the surface and conduct the heat. Higher temperat
Electronics Forum | Fri Feb 21 19:41:25 EST 2003 | neil
I have had a look at what Bob Willis say's and the answer to my problem is not there. The paste we are using has a very high viscosity and I beleive that if we reduce the metal content to less than 90% it will solve the problem. The problem is parti
Electronics Forum | Wed Sep 30 20:56:31 EDT 1998 | Tony Barry
Assuming that your components and PCB's have good solerderabillty and are stored in an air conditioned environment and kept free of contaminants then your problem sounds as though there is insufficient wetting of the component leads due to low temper
Electronics Forum | Thu May 06 19:13:24 EDT 2004 | Greg York
Watch your dwell time especially if larger components. Problem is normally associated with lower temp as well as insufficient flux coverage with larger massed boards or ground planes. Try to hand spray a board to check that fluxer operation is OK. If
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