Electronics Forum | Sun Feb 05 17:44:47 EST 2017 | spoiltforchoice
Printer->Paste Inspection(which might be a feature of the printer)->High speed placer (for all the little parts)->Accurate Placer(for your BGA Processor,RAM,eMMC and big things that don't fit in the high speed)->Reflow oven->AOI->PCB stacker All of t
Electronics Forum | Tue Jan 12 15:29:40 EST 2010 | davef
What is your concern regarding voiding in QFN solder connections?
Electronics Forum | Thu May 26 08:52:42 EDT 2011 | davef
Phil Zarrow wrote a useful paper that could help in evaluating paste. Here read it ... Evaluating Solder Paste � Not An Option Contributed by Phil Zarrow of ITM an Independent SMT consulting firm With soldering being the dominant source of assembly
Electronics Forum | Wed Jul 27 09:58:05 EDT 2011 | davef
Pressure printing systems Conventional stencil printing techniques have fundamental limitations as regards paste handling: The volume of paste available for printing is limited, so frequent replenishment is necessary Paste is difficult to c
Electronics Forum | Wed Oct 07 15:23:10 EDT 2020 | spoiltforchoice
MyCronic are literally the only ones in the market, Essemtec do Jet printing but make no attempt to sell it as a full printer replacement in the way MyCronic do. I was told by MyCronic "The MY500's are reducing in numbers now and spares support is co
Electronics Forum | Mon Dec 07 14:55:41 EST 2015 | clydestrum
So I have an issue coming up that I'm not too sure how to handle. A board was designed with the wrong footprint for a 3-lead transistor in which the single-lead side has a much larger (think thermal pad for qfn) copper land than what is meant for the
Electronics Forum | Thu May 26 16:41:00 EDT 2011 | scottp
Here's what I do: - Test Surface Insulation Resistance (we're in the high reliability market and use a test significantly harder than IPC's). I also test SIR in combination with other assembly materials like conformal coatings and wave solder flux
Electronics Forum | Thu Mar 22 17:38:44 EST 2001 | davef
OK, lemme take a different angle on this, �cuz I forgot to touch on this when I first responded. I mentioned a study ["Evaluation of Low Residue Soldering for Military and Commercial Applications: A Report from the Low-Residue Soldering Task Force"
Electronics Forum | Fri Jul 27 09:47:20 EDT 2018 | davef
Adding to Rob's suggestions ... One of the theories about voiding in thermal / ground pads of BTC is: Solder starts melting at the edge of the pad and moves inward towards the center of the solder mass. This traps flux volatilizes. So, there needs t
Electronics Forum | Tue Aug 14 08:19:45 EDT 2018 | buckcho
Hello, other colleagues gave you valid ideas. I found it helpful if i reduce the size of the cooling openings. I would suggest making the four big square into very small many diamonds. This would maybe decrease your voiding with 2-4 percent. Btw how
