There is a memory type Volatile for this type of device. It comes in a Bulk. As you can see, it is embedded in FBGA case. This device uses takes advantage of the DRAM format.
MT53B4DANJ-DC Features
Package / Case: FBGA
MT53B4DANJ-DC Applications
There are a lot of Micron Technology Inc. MT53B4DANJ-DC Memory applications.