Low-pressure drop thermal assemblies, systems and methods of making low-pressure drop thermal assemblies for use in high power flux situations. A manifold body is attached to a distributor to form a subassembly. This subassembly is in communication with a substrate surface, which has a semiconductor device in need of thermal management thereon. An enclosed cavity is formed between the target substrate surface and the subassembly, and a seal of the cavity protects critical components residing on the active surface of the semiconductor device. The distributor includes a distributed liquid impingement microjet inlet array isolated from and parallel with a distributed microjet drain array for impinging cooling fluid and removing spent heated fluid in a direction orthogonal to a target surface for maximizing the heat transfer rate, and thereby providing high cooling flux capabilities while enabling low-pressure drops.