Electronics Forum | Tue Oct 20 03:22:52 EDT 1998 | Viswanath Valluri
Hello : Some of the recent FBGA (a Chip Scale Package) packages that I am looking into have body sizes having aspect ratio's 2:1. In particular, body sizes of 14x8mm, 15x8 mm etc. The ball count for this particular package is around 40-68 I/Os. My qu
Electronics Forum | Fri Oct 23 15:19:38 EDT 1998 | Dave f
| Hello : | Some of the recent FBGA (a Chip Scale Package) packages that I am looking into have body sizes having aspect ratio's 2:1. In particular, body sizes of 14x8mm, 15x8 mm etc. The ball count for this particular package is around 40-68 I/Os. M
Electronics Forum | Fri Mar 02 10:06:28 EST 2007 | oldsmtdude
Agilent SP50 rocks for continuous improvement and pass-fail efforts. You'll see variation you never imagined you had prior. But be aware you absolutely have to monitor data and tweak your processes to improve results. Do not jump in and try and use
Electronics Forum | Mon Dec 14 15:08:46 EST 1998 | Jim Mitchell
Provided your software supports board stretch and the board is stretched in a linear fashion, you should not need fiducials for each image. If you do elect to use local fiducials, Quad recommends a single fiducial. This method is faster and you can
Electronics Forum | Tue Sep 25 15:48:34 EDT 2001 | mparker
Scavenge all the old solder off the board and the chip. Micro screen paste to the chip. As far as thickness, check your aspect ratio to determine the spec. Eliminate just one variable at a time to get to the root cause. Start by not using the tacky
Electronics Forum | Thu Aug 29 13:03:13 EDT 2002 | lysik
You have may have already checked this but verify stencil design (aspect ratio) and make sure you are using the correct paste (mesh size) Also look at perint pressure. up to 2 lbs per inch of blade used. You may also want to use a slow break away whe
Electronics Forum | Wed Jul 13 09:07:32 EDT 2005 | russ
The reason for going 1:1 with lead free is that it does not spread out like the pb solders. So 1:1 is really not necessary in my opinion. We go 1:1 anyway on discrete components along with other packages. You always have to make sure that the area
Electronics Forum | Mon Oct 17 11:16:09 EDT 2005 | slthomas
There are a lot of things that might affect your cleaning efficiency. Paste type (no clean or w/s?), cleaning chemistry, aperture aspect ratio (aperture width/stencil thickness), "linty" wipes, etc. Another thing you need to look at is the frequency
Electronics Forum | Thu Dec 08 12:24:11 EST 2005 | cyber_wolf
Any good stencil house should be able to recommend the proper configuration on a fine pitch aperture design. They can also advise you as to which foil thickness works best. The norm foil thickness is .005" - .006". There are always special instances
Electronics Forum | Mon Mar 27 20:53:12 EST 2006 | davef
If you believe: * There is air in your paste AND * You are not whipping the air into the paste ... You should: * Return the paste to your supplier * Get it replaced * Begin qualifying a replacement supplier. One thing before you go racing off to ly
