JEDEC Releases SPHBM4 Standard: Bypasses Silicon Interposers, Redirects HBM Pin Count from 2,048 to 512

According to BlockBeats, citing analyst Damnang's June 22 article, JEDEC released the SPHBM4 standard, which changes how HBM connects to GPUs. Unlike traditional HBM4 that requires silicon interposers for connection, SPHBM4 allows HBM to bypass the interposer and connect directly to organic substrates. The standard reuses HBM4's DRAM stacking while redesigning the base die, reducing pin count from 2,048 to 512 and increasing single-pin speed four-fold through 4:1 serialization to maintain comparable bandwidth.

Damnang notes that SPHBM4's key value lies in releasing advanced packaging capacity rather than reducing HBM cost. By freeing up silicon interposer area previously occupied by HBM, the same interposer wafer capacity could theoretically support 1.5 to 2 times more packages. The competitive focus in HBM development shifts from stacking height to base die logic design quality, benefiting vertically integrated players like Samsung while requiring SK Hynix and Micron to rely on TSMC for advanced nodes.