Packaging
ST Assembly Test Services (STATS) announced lead-free and "green" material options for its entire package portfolio.
The packages are qualified with enhanced moisture sensitivity level to withstand the higher reflow temperature at board assembly that is required for lead-free solders. This complies with current JEDEC and JEITA (Japan Electronics & Information Technology Industries Association) standards for lead-free reflow with a peak temperature of 260degreesC.
As part of its lead-free offering, STATS selected a tin-silver-copper alloy preferred by the majority of its customers for solder balls in BGA packages. "Green" package solutions also have "green" die attach materials, mould compound and substrate. For leadframe based packages, STATS offers pure matte tin as an alternative to tin-lead finish. STATS has also qualified a nickel-palladium-gold finish as another lead-free option. The European Commission's Directive on Waste from Electrical and Electronic Equipment (WEEE) and Restriction on Hazardous Substances (RoHS) bans the use of lead and halogen flame retardants in electronic devices from July 1, 2006, onwards.
Samsung Electronics claims the industry's first wafer level package (WLP) for 512Mbit DDR2 SDRAMs. WLP enhances the electrical properties and reduces the physical space of the finished devices. The new package technology, WLC, creates two patterned inter-layer dielectrics (ILD), with insulating characteristics, and a metal layer replacing the conventional package substrate. Ball grids are applied to give a chip scale package (CSP) that is scaled down to the actual die size. The compact new package enhances electrical properties though shorter circuit routing. The WLP supports the JEDEC specifications for DDR2 CSPs.
