Area array and chip scale packaging (BGA, CSP): The development of an LTCC top-bottom-BGA (TB-BGA)

摘要

A "Top Bottom Ball Grid Array" (TB-BGA) is described, that takes advantage of modern LTCC interconnection technology and existing BGA- and CSP-techniques, to create a new package for SCM's, MCM's, sensors and actuators. Using a pin-compatible BGA configuration at the bottom and the top of the LTCC carrier, a 3D stack assembly of several TB-BGA's is possible. Considering thermo- mechanical reliability, the compact stack assembly reduces bending loads and shear forces by using ceramic materials. The area configuration of solder balls ensures a good thermal conductivity. LTCC TB-BGA's are actually developed as single chip modules (SCM's) and few chip modules (FCM's). They will be mounted as intelligent sensor bus interfaces in conventional sensor casings. A full operating 16-bit-processor-unit including microcontroller, S-RAM, EEPROM physical CAN bus interface, oscillator and SMD components will require a volume of only 1.5 cm (Fig.1).