Electronic assemblies including substrates and their manufacture are described. One assembly includes a die embedded in a dielectric layer in a multilayer substrate, and a dielectric region embedded in the dielectric layer in the multilayer substrate. The multilayer substrate includes a die side and a land side, with the first dielectric region and the dielectric layer extending to the die side. A plurality of vias are positioned within the first dielectric region, the vias extending to pads on the die side. Other embodiments are described and claimed.