Electronics Forum | Wed Dec 06 16:48:42 EST 2006 | Mario Scalzo
I would be glad to help you eliminate the solder balling and beading that you are seeing. As this is a fairly common defect, I would like to forward you an Application Note that we have developed that explains the cause and possible solutions. Most
Electronics Forum | Thu Dec 07 00:55:51 EST 2006 | billylim
As you are aware the common method to rework BGA is : 1. Remove BGA with hot air reflow machine ( SRT as current practice) 2. Clean the BGA pad using solder iron and solder wick. 3. Replace BGA with SRT rework machine. The problem we have with
Electronics Forum | Mon Dec 18 13:00:34 EST 2006 | realchunks
Hi John, Depending on your board, it could make a difference. Copper finishes might leave that part of the pad exposed, which is a no-no in most places. Where as a HASL board prolly won't care if you pulled the print back. On the other end, over
Electronics Forum | Tue Jan 30 17:58:49 EST 2007 | flipit
Hi, I would not be too concerned about what the shape of your wirebonding fiducial is. Cross, Square, Diamond, Circle, will all work well for you. I use a "+" and a diamond. Your machine magnification will be great, so don't make the fiducials to
Electronics Forum | Thu Mar 01 19:27:48 EST 2007 | Wayne
Yes, I am currently using Viromet 347 at the moment for my SMT lines. 100-150, 35 sec 150-207, 40 sec 207-above, 80 sec peak temp: 225 deg C. It is compatible to SAC paste in term of solderability and wettability. But in term of mechanical property (
Electronics Forum | Mon Jul 16 10:44:29 EDT 2007 | Jacky
Hi All, Recently, we encountered strange defect at our SMT line. We can see solder ball spatter around at one of the component pad. This lead to insufficient solder defect at 1 side of the component. The other side of the component look good(Meet
Electronics Forum | Fri Dec 21 15:50:54 EST 2007 | rwyman
Hi smtdude- I'm no expert at PoP (yet!) as we've only done a few weeks worth of experiments for a new customer but what i can tell you is 25-50% of the ball height (not diameter) is a good rule of thumb for the flux depth, at least to start. I can s
Electronics Forum | Tue Jan 15 12:37:17 EST 2008 | gregoryyork
SORRY I did not offer a solution so here goes - The best way to get rid of this issue if you cant change flux is to reduce your flux consumption to a minimal with a spray flux and keep the heat REALLY high to boil off the alcohol before it can be abs
Electronics Forum | Wed Jan 30 15:47:13 EST 2008 | tonyamenson
Just my humble opinion. Every place I've worked at uses x-ray over optical inspection for BGAs. Companies that had both often let the optical inspector collect dust becuase you can only really inspect the perimeter solder balls. Not to mention you c
Electronics Forum | Tue Feb 12 17:57:42 EST 2008 | chef
I must ask the silly question- are you sure you deposited the correct amount of paste? Depending on aperature design-the voiding could come from a stencil that has its holes partially built up with old paste. If paste volume is guaranteed, then what
