Electronics Forum | Wed Aug 31 11:02:28 EDT 2005 | Jason Fullerton
We are using one BGA that has 7 mil bumps on a 20 mil pitch. We use the manufacturer's recommended pad and aperature layout, which is an 11.8 mil square overprint on a 6 mil land. At 11.8 square, you need to use a 4 mil laser cut or a 5 mil e-form st
Electronics Forum | Thu May 18 10:20:55 EDT 2006 | slthomas
Russ asks good questions and I think Chunks pretty much nailed it. Aspect ratio (aperture width/stencil thickness) s/b 1.2 minimum (I like 1.5 if I can get it). If your aperture width = lead width (.008"), yours is 1. Tough to get consistent paste r
Electronics Forum | Tue Oct 03 14:14:06 EDT 2006 | slthomas
What is the likelihood that we'll be able to manually dispense paste on 25 mil pitch, 20 mil pads and get away without bridges? We have a CTS Series 753 resnet we need to place and the build qty (30) and board layout (.5" x 1.2" unpanelized, 2-sided)
Electronics Forum | Thu Jan 04 10:27:47 EST 2007 | slthomas
1) determine the rate of cleaning frequency related defects your production can tolerate. 2) determine the frequency that nets you that defect rate, or lower, but also consider the cost of cleaning materials and throughput if you're cleaning very oft
Electronics Forum | Tue Mar 27 16:29:52 EDT 2007 | dyoungquist
We are a high mix - low/medium volume company running an older MyData upgraded TP9 machine. It does a good job placing 20 mil pitch and 0402 components. We have not tried to place 15 mil pitch. Breakdowns/repairs have been relatively low consideri
Electronics Forum | Sat Apr 07 01:15:45 EDT 2007 | Haris
Hi I dont think there is a stencil problem or a printing one but i think you should check you paste specification regarding 20 mil pitch i.e. its ball size in microns so that you know Is that paste can be use for this type of components or not. Secon
Electronics Forum | Thu May 31 19:45:47 EDT 2007 | diesel_1t
We place a QFP 256 leads 20 mil pitch, had a lot of troubles with shifted components and solderability issues. solderability is not a problem anymore; we solved with a ramp-to-spike profile with .9�C/s 'til 183� then spike to about 118�C, TAL ~60s. W
Electronics Forum | Wed Aug 22 09:53:06 EDT 2007 | slthomas
"The question is: should we be looking at the operator? the paste? or the setup?" Yes. ;) Those guys love to brag about their 4 corner height adjustment on those printers. The fact is it's a PITA and shouldn't be necessary in the first place. It's
Electronics Forum | Fri Jun 13 10:35:30 EDT 2008 | pjc
Its a bit of an old beast, it was replaced by SE 200 and is now discontinued (since 2004 I believe). Its a decent unit, but hard to achieve good repeatability on smaller deposits. Its also not reliable on small solderpaste below 20mil fine-pitch. Fai
Electronics Forum | Fri Aug 01 00:40:06 EDT 2008 | roc2x
thanks,my pad design is 24 x 23 mils and now I chnged my stencil to 24 x 20 mils ship inwrds to lower down my volume. My placement is and part data are ok. My reflow N2 is using 1000ppm, Actual is 700-800ppm I already prolonged my pre-heat butit only
