The development of a modular 32 Bit microcontroller MCM in top bottom BGA (TB-BGA) technique

A modular 32-bit microcontroller MCM is described, that takes advantage of the TB-BGA technique developed by IZM. By using a pin compatible BGA configuration at the bottom and the top of the MCM carrier, a 3D stack assembly of several TB-BGAs is possible. The existing ceramic TB-BGAs form a 16 bit controller family, consisting of microcontroller, memory and interface modules. A full operating 16 bit processor unit requires a volume of only 1.2 cm3. Considering thermomechanical reliability, the compact stack assembly reduces bending loads and shear forces by using suitable materials. The solder ball area configuration ensures a good thermal conductivity.