Electronics Forum | Mon Oct 13 13:49:29 EDT 2003 | mrmaint
Does anyone know of a standard stencil thickness for BGA'S. We currently use 4 to 5 mil stencils depending on component mix. Is an aperature reduction required for BGA'S. If so what percentage. Any help would be greatly appreciated. Thanks MRMAINT
Electronics Forum | Mon Oct 13 19:04:47 EDT 2003 | davef
Aperture size should vary with the component [pitch]. That size should be the same a the pad size. So, generally pinching is not required. Indium discusses BGA apertures on their site [ http://www.indium.com ]
Electronics Forum | Thu Sep 12 01:49:28 EDT 2002 | ck
Hi all, Any stencil opening recommendation for 20mils pitch mirco BGA. Currently, using 12mils round opening, 5 mils thickness. Seen to have weak joints as it crack after Ict testing. thks
Electronics Forum | Wed Sep 25 11:11:14 EDT 2002 | xrayhipp
Try .005 or even .004 thick laser cut electopolish stencil and reduce grain size of paste. Go with 400 or 25 in the case of AIM. We had a similar prob.
Electronics Forum | Thu Sep 12 10:45:29 EDT 2002 | pbarton
We have used a laser cut stencil 0.15mm (0.006") thick with 0.3mm (0.012") square apertures radiused in the corners 0.06mm (0.0025") to aid paste release. This approach with the (type 3) paste we use has proven successful on thousands of devices plac
Electronics Forum | Fri Apr 11 01:52:26 EDT 2008 | andrzej
0,66 Is it ok ? Is it overprinted r - radius of stencil aperture - 9mils ~ 230um t - stencil thickness - 150um Other data : diameter of soldermas - 26mils Diameter of pad - 18mils Diameter of stencil apertre - 18mils Pitch - 0,8mm ~ 31mils What s
Electronics Forum | Fri Apr 11 06:22:04 EDT 2008 | andrzej
Hi Andrzej, > > We are using for BGA (0.8 pitch) > square apertures size 0.4 mm (rounded corners r = > t) and stencil thickness t=5 mils. So area > ration-_ w/4t=0.8 > > Regards Jan Hello Jan, I understand that you have the same pad dimensio
Electronics Forum | Thu Jun 09 07:02:02 EDT 2005 | ajaydoshi
1. We do have PCB with 0402 component, Micro BGA ( 0.5mm pitch , 0.25 mm pad size ). PCB thickness is 0.8mm. What stencil thickness we should use. PCB size 40 mm X 60 mm 2. We have EKRA E4 , What will be optimum setting for above. Pressure, Scquge s
Electronics Forum | Thu Jun 16 18:19:05 EDT 2005 | Jason Fullerton
If the uBGA has aperatures that are 0.25mm square, you need to use a laser cut foil no thicker than 3.75 mils to get an area ratio of 0.67, which is the minimum rule of thumb - that's too thin! Electroform would probably work up to 4.5 mils thick.
Electronics Forum | Thu Jun 09 13:30:34 EDT 2005 | PWH
I would suggest 7mm thick "Durostone" as a carrier material. Cut lip/pocket for PCB so it is 0.05" thinner than thickness of PCB. Allow 0.010" gap on all sides of PCB. Machine lip to width between 0.050" and 0.100" to support under perimeter sides
