Electronics Forum | Thu Jan 22 12:21:54 EST 1998 | Michael Allen
Is there a standard (JEDEC or other) for "lead sweep" errors on fine pitch (eg, 0.5mm) gull wing leads? Parts from one of my suppliers has a sweep error up to 6 mils; the mechanical drawing does not address lead sweep error, nor is there a true posi
Electronics Forum | Tue Dec 19 21:23:39 EST 2006 | davef
We'd suggest using your connector supplier recommendations. Some use: * Pad Plating: 20-30 uin Au over 50 uin Ni (You might get away with less gold) * In-Pad Vias: less than half the diameter of the button (for contact-only configurations) * PCB/C
Electronics Forum | Tue Nov 13 22:40:02 EST 2012 | davef
I expect that suppliers can just about always hold solder mask registration within a true position of 3 thou. That's the old SMT padstack think ... make the solder mask openings extend 3 thou larger than the copper. That way, even if the copper and t
Electronics Forum | Sat Feb 14 13:28:47 EST 1998 | ASHOK DHAWAN
I am beginer in BGA assembly and am confused in selection of pick and place option. As per book on 'implementation of BGA Technology-by 1995 aeic inc. states that BGAs reflow is quite forgiving and you need only Mechanical centering of PBGAs. The IPC
Electronics Forum | Sun Feb 15 18:07:18 EST 1998 | Scott McKee
| I am beginer in BGA assembly and am confused in selection of pick and place option. As per book on 'implementation of BGA Technology-by 1995 aeic inc. states that BGAs reflow is quite forgiving and you need only Mechanical centering of PBGAs. The I
Electronics Forum | Sat Feb 14 13:33:10 EST 1998 | ashok dhawan
| I am beginner in BGA assembly and am confused in selection of centering method on pick and place operation.. As per book on 'implementation of BGA Technology-by 1995 aeic inc. states that BGAs reflow is quite forgiving and you can use Mechanical c
Electronics Forum | Fri Apr 06 22:40:24 EDT 2007 | oldsmtdude
After thinking some more: Feeder offset is usually an averaged number... If feeders get erratic feeder offset goes wacky. Nozzles don't seal, components slip and vision isn't getting the true pick position. And worse they may move again post vision
Electronics Forum | Mon Feb 25 21:09:48 EST 2002 | davef
You are correct about a TCE [CTE] mismatch issues in ceramic packages. The coefficient of thermal expansion [ppm/�C] of major ceramic package elements are: * Silicon - 3 * Standard 92% alumina ceramic � 6.5 * FR4 board � 18-20 Several points are: *
Electronics Forum | Thu Apr 30 16:00:50 EDT 2009 | joeherz
Fids ON the PCB will have a reference to the PCB 0,0 point in CAD data generally or can be measured with good accuracy in gerber if CAD is not available. Panel fiducials are not always referenced from the PCB 0,0 point but many times are referenced
Electronics Forum | Fri Mar 06 10:30:46 EST 1998 | Ron Costa
| | | Hello everyone! | | | Does any know anything about bare board size variations? | | | Is there a spec. or tolerance? | | | I'm running small lots of boards and during the screen printing process | | | I find that I cannot paste each board perfec
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