Electronics Forum | Mon Jul 12 13:27:35 EDT 1999 | Upinder Singh
Hi all , We are trying to implement the micro-BGA technology at our plant. I need the clarification to the following points: 1. Is underfill required for micro-BGAs? 2. What type of stencil apertures are the industry standards for uBGAs and of wha
Electronics Forum | Tue Jun 28 14:06:08 EDT 2011 | dmiller
If you have room, and the aperture size will allow for it, try a 5 mil overall stencil thickness with a 1 mil step-up in the area of the BGA connector.
Electronics Forum | Mon Mar 27 08:28:48 EST 2000 | Mark Alder
Dear Robert The reason for the bridging problem you are experiencing on your BGA's is due because of too much solder. The PCB pads need to be at least 15% larger than the sphere size of the BGA balls. If you are not using C4 (63/37) BGA spheres and
Electronics Forum | Thu Nov 03 10:49:11 EST 2005 | russ
This is what I would propose, Place and reflow the board without the BGA with your lead process, remove the solder from the BGA pads if you cannot mask off the apertures in your stencil. Then place the BGA and reflow to SAC requirements with a rewo
Electronics Forum | Tue Sep 21 12:10:23 EDT 1999 | Mario
| I've had some trouble pasting a test board for a MicroBGA trial. Most of the paste remains in the stencil apertures. | The stencil is 6 mil thick, laser cut and electo-polished. | The apertures are 12 mil in diameter with 20 mil pitch. | We are usi
Electronics Forum | Mon Sep 20 17:46:21 EDT 1999 | Dave F
| I've had some trouble pasting a test board for a MicroBGA trial. Most of the paste remains in the stencil apertures. | The stencil is 6 mil thick, laser cut and electo-polished. | The apertures are 12 mil in diameter with 20 mil pitch. | We are usi
Electronics Forum | Sat Jun 23 11:41:34 EDT 2007 | grantp
Hi, We use 1:1 for 1 mm BGA and it works fine. We used it at 4 thou laser cut stencils when we had a manual stencil printer, but have moved to 5 thou with the DEK and it works ok. We originally went to 4 thou because of paste release, but the DEK
Electronics Forum | Wed Apr 28 04:26:24 EDT 1999 | Nigel Burtt
| Hello all, | | I read about Steve's headache a few articles back and I'm really interested by his tip. However, I'm still wondering why square apertures release solder paste better than round ones. For the same volume of paste, the surface area
Electronics Forum | Tue Sep 21 11:28:26 EDT 1999 | Dave F
| I've had some trouble pasting a test board for a MicroBGA trial. Most of the paste remains in the stencil apertures. | The stencil is 6 mil thick, laser cut and electo-polished. | The apertures are 12 mil in diameter with 20 mil pitch. | We are usi
Electronics Forum | Thu Feb 24 06:09:26 EST 2000 | Robert Hutton-Squire
Hi, - any suggestions welcome... I have a 484 pin ALTERA fineline BGA - ball pitch 1mm (40) - ball size 0.48mm (18.9) What would you recommend for... 1. Surface pad size for the balls of this BGA device? 2. Stencil thickness/type and hole a
