MCM-L requirements for an automotive electronic control unit application

MCMs offer an attractive alternative to packaged components to increase the packaging density and the reliability of electronic functions in a harsh environment, and decrease the overall cost. In the first part of this paper, we show the results of reliability tests carried out on test vehicles to select from the possible technological choices-high T/sub g/ FR4 vs. BT resin base substrate materials; wire bonding vs. flip chip processing for VLSI assembly on the MCM-L; and glob top encapsulation vs. metal lid die protection technology-to find the technologies which best fulfil automotive requirements for under the hood applications at a competitive cost. In the second part of the paper, we describe a functional MCM-L/ball grid array (BGA) electronic control unit (ECU) built with the materials and processes selected.