Is there a specific certification for QA dept in product based companies?

I think that TMMi should be an option for that. The TMMi Foundation is a non-profit organization, which supports organizations around the world to improve their software and system testing and achieve higher and sustainable levels of product quality for the systems they are developing and maintaining. With TMMi, these organizations can assess and improve their test processes in a cost effectively manner and, if required,  become formally certified.