SK Hynix HBM4 Yield Reportedly Tops 70%

Yield is the quiet variable that decides whether HBM4 supply can scale, and a reported move past 70% matters less as a headline number than as a sign that output per wafer is improving without new capacity. SK Hynix's silence on the figure is itself notable, since undisclosed yields leave customers and rivals working from estimates. The customers exposed here are the accelerator makers whose roadmaps depend on HBM4 volumes rather than pricing. Whether the reported level holds in volume production, and whether SK Hynix confirms it, is the open question.