Reliability Evaluation of a PBGA MCM for Automotive Applications
Authors: Andrew Mawer Company: Motorola Semiconductor Product Date Published: 4/28/1997
Surface Mount International
Abstract: To date, wire-bonded Plastic Ball Grid Arrays (PBGA) of various configurations have been filly qualified for applications that include pagers, mobile radios, personal computers, workstations and telephone equipment. Besides some military and space applications, arguably the most severe service environment for an electronics package is automotive under the hood. This paper will cover the interconnect and, to some extent, the component-level reliability testing that was undertaken to prove out the feasibility of a three-die multi-chip module (MCM) packaged in a 352 pin PBGA for an automotive under hood transmission controller application. The MCM replaces three leaded packages that contained a microcontroller, an ASIC and Flash memory. Specifically, package to board thermal cycling testing, finite element modeling, analyses of package mechanical behavior using Moire interferometry and the results of component-level stressing will be outlined. Additionally, the aspects of the MCM that were optimized for reliability during the design phase will be discussed. The testing and analysis performed so far indicate that the performance of the proposed MCM will meet Motorola’s internal reliability and functionality requirements as well as those of the end user.