Electronics Forum | Thu Jul 15 21:18:27 EDT 1999 | Scott McKee
| I'm designing a board where the parts will only fit if I do one of the following: | | 1. Put BGAs on both sides | | 2. Put BGAs on top, smt TSOPs directly underneath and using blind vias to keep the real estate on the bottom side below the BGA pa
Electronics Forum | Thu Aug 06 13:02:11 EDT 1998 | Brian Stumm
Tombstoning is often caused by non-uniform heating. I suggest you check you profile to ensure you still have uniform heating and also check your rise and cool rates. If you have a convection oven I would look into the fan speeds or airflow rate throu
Electronics Forum | Fri Jun 12 14:22:53 EDT 1998 | Ryan Jennens
| Hey all! | The wave solder warrior is back. I have found a flux which leave almost no residue (the least yet), but because of its super low solids content I absolutely cannot get topside fillets. The multi-layer, two sided board is on a pall
Electronics Forum | Wed Jun 03 10:25:49 EDT 1998 | Justin Medernach
| Can anyone tell me if there is a reference for smt component height specs on the bottom side of a board, which will also go through wave soldering. A current design I am reviewing has tant caps(7343) and a crystal on the back side. Should I only b
Electronics Forum | Tue Oct 28 17:40:58 EST 2003 | davef
We theorize a secondary [bottom] side BGA can be wave soldered with planning. Issues are: * Keepout between the BGA and one side of the board that is clear of PTH parts requiring wave soldering, so to support the fixture. * Keepout around the BGA. *
Electronics Forum | Wed Apr 04 19:10:20 EDT 2007 | rgduval
Pete, Top-side temp might be an issue. What's the easiest way to check it? I seem to recall some thermal decals that we used to use a couple of jobs ago. I spoke with the flex manufacturer, and they recommended 4 hours at 250 degrees pre-process
Electronics Forum | Mon Jan 21 08:28:33 EST 2013 | proy
I am looking at assembling a relatively small baord, but it is very thin and precise. It is .010" FR4, with 1oz copper two sides. ** Components are only on one side** It has some 0201's and a .4mm pitch BGA among other leadless packages. Where
Electronics Forum | Fri Jun 06 13:03:01 EDT 2014 | asksmt
Hi All, i have footprint 2X5 RA HEADER 2MM spacing in design. I am using about 9 mils of annular ring on top side and about 12 mils of annular ring on bottom side. refer picture attached. we are having solder short issues during wave solder so was
Electronics Forum | Thu Mar 01 19:38:12 EST 2007 | Wayne
1) run the BGA side first. set the bottom temp lower (if your reflow oven have top and bottom temp setting) for connector side while doing your 2nd reflow. 2) run the BGA side first with your normal leadfree paste, and run the connector side with low
Electronics Forum | Mon Jun 07 10:57:31 EDT 1999 | Dave F
| | | | Where I can find some informations about repairing of SMT boards? | | | | | | | | Thanks | | | | | | | | Marcos | | | | | | | A first place to start is IPC's 7711 and 7721 encompasing repair, modification, and rework procedures. | | | |
