Materials methodology to improve the delamination strength of laminar composites

Fiber based z-directional reinforced composites having enhanced inter-laminar strength, impact toughness, transmission properties (electrical and thermal conduction) and coefficient of thermal expansion are provided. The composites include at least two substrates separated by a reinforcement zone that includes a plurality of fibers disposed in a binder resin. At least some, and in one embodiment, a majority, of the fibers are oriented so as to be substantially perpendicular to the substrates. Multi-layered composites having more than two substrate layers can also be formed. Methods for forming such composites are also provided.