Electronics Forum | Mon Dec 03 12:15:51 EST 2007 | rgduval
We've just completed an experiment for one of our customers using lead-free HASL. From a manufacturing standpoint, everything seemed to have run fine. Solder profiling seemed to be unaffected, pick and place was unaffected, and the end result looke
Electronics Forum | Tue Jan 24 20:00:39 EST 2012 | kahrpr
If you failed math like I did. A 0.005 inch stencil would work fine for those parts. Most stencils are 0.004in for fine pitch 1005s 201s. 0.005in is probably the most common generic stencil. 0.006in generally is if you need extra solder for big parts
Electronics Forum | Fri Mar 15 18:44:34 EDT 2013 | anvil1021
We will try both the solder mask and the .001" Kapton and see where we end up with each. This is a fine pitch dual row QFN and we cannot afford too much paste on the .004" stencil we are using. We have experienced shorting in the past with .005" sten
Electronics Forum | Thu Feb 12 20:36:26 EST 1998 | Jon Medernach
| Using metal squeegees on GSPs has caused premature stencil wear. Has | anyone had any success with this combination? How much snap off did you | use? We are using .5 mm pitch and have a no clean process. Stencil wear is is minimal but exists. T
Electronics Forum | Thu Dec 08 08:22:58 EST 2005 | grantp
Hi, How fine pitch are you going? What kind of stencil printer are you using? We had a manual stencil printer and needed to print 1-mm pitch BGA and needed to go to laster cut and electro polish at 4 thou to get good paste release. We also went 1:1
Electronics Forum | Thu Jul 28 07:23:24 EDT 2011 | scottp
My group supports a couple hundred lines all over the world. Most of them use squeegees but a few use either the MPM Rheometric pump heads or the DEK Proflow heads. I absolutely hate the enclosed heads. Flux separation, compaction, and the print q
Electronics Forum | Thu Nov 30 21:13:55 EST 2000 | Dave F
Can't find "WS601" on the Alpha site. What is that stuff? So, with nothing to go on, I'll just guess ... Yer probably cold welding the solder particles together. The nozzle size (inside diameter) determines the dot size. * With glue, small dot si
Electronics Forum | Fri Apr 09 15:41:11 EDT 1999 | Matt Stackhouse
| DOES ANY ONE KNOW HOW I CAN STRAIGHTEN | BENT PINS ON A FINE PITCH QFP WITH OUT DAMAGING | THE CHIP. AT $300 A CHIP I CAN'T SCRAP THEM. Here is a neat trick if you have the equipment. If your company does any feature measurement of mechanical de
Electronics Forum | Fri Sep 17 03:13:00 EDT 2010 | grahamcooper22
In HASL pcb coating you need to fully coat the pads with solder and then blow off any excess solder to leave a nice coating on each pad. Generally pcb manufacturers try to give you a flat pcb pad to make your solder paste printing more consistent. To
Electronics Forum | Tue Mar 21 20:36:11 EST 2000 | Dave F
Armin: Boca makes some good points about release. So, let me spin this up from a different angle ... SM-782 suggests "full radius corners" as an alternative to the more familiar square corner pads on PLCC, TSOP and QFP. We see both also. We thin
.gif)
