A heat sink assembly for removing heat from an electronic device and comprising a base, a lid in spaced relationship with and parallel to the base, and an outer wall spiraling radially outwardly about an inlet axis from an inner exit position to an outer exit position to define a tangential outlet between said exit positions. Each of a plurality of curved fins presents a concave surface and a convex surface and extends from an inner circle with radius concentric with the inlet axis to an outer circle with radius concentric with the inlet axis to define a plurality of curved channels between adjacent fins for directing the flow of cooling fluid radially from the inlet axis. Each of the curved channels is disposed at a constant distance between next adjacent fins for a major length there along from the inner circle with radius toward the outer circle with radius. That substantially constant distance extends from the inner circle with radius to a perpendicular position where the convex surface of that fin is perpendicular to the intersection of the outer circle with radius with the next adjacent fin to the convex surface.