COPPER PANEL FABRICATION AND STACKING CONCEPT FOR VLP FB DIMMS
Author: Peter C. Salmon Company: Peter C. Salmon, LLC Date Published: 11/1/2006
IWLPC (Wafer-Level Packaging)
Abstract: A new concept for fabricating very low profile fullybuffered dual in line memory modules (VLP FB-DIMMs) is proposed. Interconnection layers are built up on copper panels using high resolution photolithography. The copper substrate provides a built-in heat spreader. 8-high die stacks are employed. A new Copper-Pillar-Well (CPW) flip chip connector is used; it provides convenient rework of all 144 memory chips in each module, without melting any solder. The same connectors enable the Advanced Memory Buffer (AMB) chip to be attached within the width limitation of 18.3 mm for the VLP module. Improved electrical, thermal and mechanical properties are potentially achievable, enabling 16 GByte modules having advanced specifications.