Thermal management of a C4/ceramic-ball-grid array: the Motorola PowerPC 603/sup TM/ and PowerPC 604/sup TM/ RISC microprocessors

Abstract

This paper presents various thermal management options available for controlled-collapse-chip-connection (C4) die attached to a ceramic-ball-grid-array substrate (CBGA), as they apply to low-end/midrange computer products. Computational-fluid-dynamics (CFD) methods are used to solve the conjugate heat transfer problems. CFD modeling is used to predict die-junction temperatures for the PowerPC 603 and PowerPC 604 microprocessor in a single-chip C4/CBGA package. The focus is the die temperature rise for a limited range of boundary conditions, including: substrate conductivity, heat sinks and heat sink attach. For the PowerPC 604 microprocessor die-junction temperature rise is presented for convective air cooling (to 4 m/s) using several commercially-available heat sinks.