I'm fairly new to the OrCad package. I'm trying to create a footprint for a DDR2 IC (MT47H128M16RT-25E:C) I'm going to use in my system. This IC comes in a 84 ball BGA package with 0.45mm ball diameter. What padstack do I use?
I'm using the Package Symbol Wizard. There is something called "Bgapad" in the padstack list, but it's not working, all I get when I'm done with the wizard is a polygon with no pins.
Thanks for the help in advance :)
Well, for now, I'm using the 4MM_RD padstack, with a width of 15.75mils(0.4mm).. It's the same padstack used by the OMAP-L138 footprint that I'm using provided by TI. The balls on the L138 seem to have the same dimensions(or at least within the same range: tolerance levels of 0.55/0.45 on the L138, while the DDR2 IC only states ø= 0.45) with the same pitch(0.8mm).
Someone please let me know if I'm way off. (I'm also fairly new to PCB design in general, as you might have guessed)
The padstacks provided are just sample libraries. If you need a padstack of a different size then use the Pad Designer to create new ones. This way you can design a bga pad to suit. Have a look for c:\cadence\spb16.x\doc\algrolibdev\algrolibdev.pdf for details of pad and footprint creation.