Electronics Forum | Fri Dec 10 08:42:37 EST 2004 | mattkehoe
We had some bad experiences trying to work with soldermask defined BGA pads. If the opening in the soldermask is right to the edge of the copper/pad without a space it can leave reside on the pad and nothing will stick to it. See http://www.sipad.com
Electronics Forum | Fri Dec 27 10:04:56 EST 2002 | haran
Big pad located at the middle of the package. On the PCB,we need to have solder paste printed on the thermal pad which is at the middle and the other pads of the perimeter BGA.
Electronics Forum | Fri Dec 27 09:45:04 EST 2002 | emeto
what exactly do you mean by big thermal pad?
Electronics Forum | Wed Feb 19 19:24:12 EST 2003 | arturoflores
Is there any way I can attach a report?
Electronics Forum | Thu Dec 09 07:46:42 EST 2004 | davef
We did this for BGA pads, but have not thought about other types. So, this may or may not apply for those. Pad defined by:||Advantages||Disadvantages Non-solder mask||No point-of-stress concentration at edge mask and solder ball||Smaller pads have
Electronics Forum | Thu Feb 12 11:35:17 EST 2004 | Kris
what is the composition of the paste and ball ? Interesting to know why the customer is asking you to look for it Thx
Electronics Forum | Tue Feb 26 07:55:23 EST 2002 | cyber_wolf
I know that there is an IPC spec. for board pad size design for BGA components. After a little research we have found that recommendations vary from component manufacturers to board houses. (These recommendations are different than what IPC says....
Electronics Forum | Tue Feb 26 08:02:30 EST 2002 | cyber_wolf
I know that there is an IPC spec. for board pad size design for BGA components. After a little research we have found that recommendations vary from component manufacturers to board houses. (These recommendations are different than what IPC says....)
Electronics Forum | Tue Feb 26 10:42:48 EST 2002 | davef
Consider the hierarchy presented in http://www.smtnet.com/forums/Index.cfm?CFApp=1&Message_ID=18112
Electronics Forum | Fri Dec 27 14:11:18 EST 2002 | cnotebaert
We have placed these parts. I have not had problems with them but when I designed the stencil we reduced the app for the large thermal by 20% to reduce the chance of problems like your having. If the balls are close (.040-.050" or
