Electronics Forum | Wed Sep 12 03:52:45 EDT 2018 | shascoet29
Hi, Is the IPC-A-610 applicable to CSP assemblies? Especially regarding the solder ball to solder ball distance versus the minimum electrical clearance for assembly(0.13mm/IPC-A-610). With a 0.4mm pitch component and 260 microns diameters balls, thi
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 | Wed Nov 12 08:50:08 EST 2008 | greene08
I am trying to find a standard for HASL - especially for small pitch devices. Are there better options than HASL for boards with a large amount of small pitch IC's??
Electronics Forum | Wed Nov 12 09:32:30 EST 2008 | markhoch
Are there better options? Dude, EVERYTHING else is a better option. Gluing aluminum foil down to the bare copper would be a better option. ENIG (Electroless Nickel Immersion Gold), Immersion Silver, Immersion Tin, and OSP all provide flatter surfac
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 | Tue Feb 22 12:03:32 EST 2005 | russ
You may to reduce a little bit more with HASL. for .4mm pitch and such I would maybe go to a 5 mil with your standards.
Electronics Forum | Mon Feb 21 18:13:23 EST 2005 | gpaelmo
As davef states above, you would like to have flat surfaces below 25 mil. We are a contract manufacturer also and we've done thousands of 15 mil QFP's with HASL finish with no problems. Your success will depend on quality of PCB supplier providing th
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 | Wed Dec 18 12:04:53 EST 2002 | slthomas
That issue (gasketing is what I usually see it called) was the driving force behind us getting new printers. Our old semi-auto clamshells just weren't repeatable enough, particularly over changes in squeegee travel direction. If the paste in the
Electronics Forum | Thu Jul 05 08:11:45 EDT 2007 | naynayno
This is wave soldering process and design question since most folks associated with SMT are processing mixed assemblies. We have a 3-leaded sensor (radial) with such a tight pitch always bridges. Solutions unders disussion are pre-forming and addin
