Electronics Forum | Wed Jan 21 10:41:57 EST 2004 | davef
Depending on how you frame the question, either of you could be correct. Neither of you mentioned stencil thickness, which together with aperture opening [and stencil fabrication technology] define how well a paste will release. So, the key measure
Electronics Forum | Fri Mar 16 07:22:50 EDT 2007 | cyber_wolf
I am not sure what the smallest aperture is that I have. I can tell you that I remember the area and aspect ratio (for apertures) being quite a bit lower than standard on quite a few stencils. We only order Invar on stencils that fall below ratio..
Electronics Forum | Sun Sep 27 22:39:55 EDT 2009 | rajeshwara
The same issue i faced 2 yrs before , i sugest 1. Use stencil of 4 mils ( Take care of Aspect Ratio and Area Ratio ). 2. Use Solder Paste of Type 4.5 and Viscosity in between 1100 to 1300. ( Try Solder Paste of Cookson or Alpha metals : OM338 T45-L
Electronics Forum | Thu Mar 03 18:09:06 EST 2005 | gpaelmo
We also use Indium NC-SMQ92J. We do the same as mentioned per Russ. We reduce apertures mostly on QFP's with pitch of 25 mil or less (we place down to 15 mil QFP). All other apertures we keep 1:1. We print resnet 0805 size with no problems. You might
Electronics Forum | Mon Nov 13 08:24:03 EST 2000 | G. English
Richard, From your description of the IC, as Wolfgang indicates it sounds like a 20mil pitch device, the aperture design really depends upon your solder paste particle size, we use a type 3 solder paste with a mesh size of �325 / +500microns. This is
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
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