Electronics Forum | Thu Jun 16 09:13:46 EDT 2005 | russ
We use a 5 mil for 16mil pitch QFPs, Make sure that the stencil has been polished. Type 3 paste. We have used lead free no-clean, lead no-clean, and water soluble lead pastes for these packages. We set the printer for a slow stroke .7 in/min. wi
Electronics Forum | Thu Jun 16 00:24:29 EDT 2005 | mskler
Hi everybody, Can some body tell me that what stencil thicknes is required for the 16mil QFP. I am getting bridging as well as dry at QFP pins. What type of solder 1. Viscocity 2. mesh size 3. flux contents Should be used for this type
Electronics Forum | Thu Jun 16 08:31:15 EDT 2005 | jh0n!
The most part I have the most difficulty with is a 16mil QFN. We found that reducing stencil thickness to 4mil, and reducing aperatures for the IC by 20%, and setting local fiducials to the IC helped immensely. We used to get 75% or more bridged ou
Electronics Forum | Tue Feb 22 10:44:12 EST 2005 | Dougs
when you talk about stencil design, what would you recommend for aperture size on fine pitch if the customer insists on hasl finish on fine pitch devices? i usually use a 10% reduction on everything we have been using ( 16mil pitch and upwards and 0
Electronics Forum | Sat Oct 07 16:31:56 EDT 2000 | Elfego
Tray the electroform stencil.
Electronics Forum | Sat Oct 07 11:14:39 EDT 2000 | Aaron
1. It is hard to tell, but your PCB vendor should test the PCB. 2. I think the important thing is the width of the apertures. You should have it laser-cut, and control the width no more than 90% of half pitch. Good luck.
Electronics Forum | Sat Feb 10 18:33:52 EST 2001 | arturoflores
check the archives (keyword="16 mil pitch") and also consider 45 degree pattern printing. Regards.
Electronics Forum | Mon Oct 09 19:56:41 EDT 2000 | Dave F
CJ: Arturo and the others make good suggestions. Consider: IPC-7525 Stencil Design Guidelines
Electronics Forum | Mon Feb 21 10:05:33 EST 2005 | Dougs
Our machines can place components down to 16mil, I've never seen any finer pitch components in use, what pitch are they going down to now? 12mil??? What pitches have you been using? We are a contract manufacturer so customers sometimes supply free
Electronics Forum | Sat Oct 07 04:02:50 EDT 2000 | C.J. Long
Good morning, All: I am from PCB shop and one of our customer is experiencing solder bridge on 16 mil pitch QFP( immersion gold finish). Land width requirement is 8 +/- 1 mil measured over top of of land and our mean is 7 mil. Bottom land width is 8
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