Electronics Forum | Thu Dec 15 06:24:34 EST 2005 | tk380514
whats the pitch of the BGA�s and the stencil thickness?
Electronics Forum | Thu Dec 15 08:20:39 EST 2005 | jhernan9
The BGA pitch is 0.8 mm and stencil thickness is 0.005"
Electronics Forum | Wed Dec 14 23:32:19 EST 2005 | jhernan9
Hi, I'm having a lot of problems with BGA's shorts, we are using 0.005" stencil aperture 1 to 1 (0.014)", the paste is centre (I can not measured the height)was verified using electronic microscopie, the placement is centre (I'm using local fiducials
Electronics Forum | Thu Dec 15 09:05:44 EST 2005 | russ
These random shorts, are they most prevailent on the edges, corners, or truly all over the place. It almost sounds like package warp/delamination or something of that nature. Are you baking parts per MSL requirements?
Electronics Forum | Thu Dec 15 11:06:05 EST 2005 | Samir Nagaheenanajar
You might wanna try a small reduction in your stencil aperture. For example, for a 30-mil pad go 26-mil square aperture with 8 to 10-mil radius on your corners. Also, look at your designs. Is there enough resist between your pad and ball? Another
Electronics Forum | Fri Nov 25 09:31:56 EST 2005 | davef
pyramus, First, search the fine SMTnet Archives for previous discussions on BGA shorts. Second, we're still not clear on the issue. * Is the problem with a BGA? If so, please describe the BGA, including any heat spreader * Is the problem with a uB
Electronics Forum | Wed Apr 25 10:53:49 EDT 2001 | wbu
Zam_bri: If it were a mystery .... there can�t be any answers . Possible causes: - Short is in the PCB ( not very propable, cause you�ve checked that ) - Short is in the BGA ( not very propable, cause you�ve checked that ) - Short occurs due to so
Electronics Forum | Wed Nov 23 07:39:14 EST 2005 | chunks
Shorted to the sheild or the BGA balls are shorted? Sheilds move a lot during reflow. If this is the case, place some adhesive or peelable solder mask on either side of the shield and baords to stop it from moving.
Electronics Forum | Wed Apr 25 13:28:12 EDT 2001 | davef
You can make bare BGA balls short together, depending on how you choose to heat the device. Lookit .. [http://davesmt.50megs.com/pictures/ select bgashortng.avi]
Electronics Forum | Wed Apr 25 23:51:13 EDT 2001 | spchua
Hi, Guy, please check the lamination of the PCB's; or the the BGA rework machine, some things like m/c levelling, and force placement head
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