cub_fanatic :
AMD helped Hynix develop HBM but they do not own the patents. Also, Hynix is supposedly giving AMD priority over Nvidia on HBM and HMB2 when Nvidia starts shipping Pascal GPUs. http://wccftech.com/amd-working-entire-range-hbm-gpus-follow-fiji-fury-lineup/
The caveat to this is that Samsung is also manufacturing HBM2, so whilst AMD will get exclusivity with Hynix, nVidia will probably just go with Sammy instead
😛