This web site is a great help if you want to discover manufactory info about your iPhone and iPad.
It can even tell whether your unit is refurbished or not.
This is the report from my iPad 2
Name: iPad 2
Machine Model: iPad2,2
Model introduced: 2011
Production year: 2011
Production week: 47 (November)
introduced test: GOED
CPU speed: 1.0GHz
Family name: Become a pro user to see this information. (sorry)
Screen size: 9 inch
Screen resolution: 1024×768 pixels
Factory: DL (China – Foxconn)