Memory Packaging Material and Assembly Trends

This paper reviews the packaging designs available for DRAM DIMM modules and miniaturized, removable digital flash cards using NAND chips. For present day DRAM modules the packages are switching from leadframe types to chip scale packages (CSP). For the flash cards leadframe packages, CSP and chip on board (COB) are all being applied, depending on the card type and size. Current and future module and card design and their assembly trends are discussed. Due to lead-free requirements, all packages and materials must meet the high reflow temperature conditions used for lead-free assembly.