As reported in Korea IT Times, Samsung rolled out a “50nm class” 1Gbit mobile DRAM with wide I/O capable of a 12.8Gbytes/sec transfer rate at last week’s ISSCC. The key to achieving a transfer rate that’s 8x faster than conventional mobile DDR DRAM and 4x faster than LPDDR2 is the use of wide I/O paths. In this case, the DRAM interface uses 512 pins for data transfer instead of the conventional 32-pin design. Conventional DRAM packaging cannot achieve such an I/O density, Samsung uses microbumps and TSVs (through-silicon vias) to permit 2.5D assembly and full 3D packaging with device stacking, for even better volumetric efficiency.
The introduction of this DRAM won’t immediately create a “3D revolution” in Silicon or System Realization. However, Samsung’s introduction of a 3D-specific DRAM for mobile applications is yet another signpost, or perhaps a billboard, on the road to the packaging revolution now underway.