heatsink structures for integrated circuit chips , chip packages , printed wiring boards and the like are disclosed . the heatsink structures according to the present invention have thin flexible cooling fins which move and vibrate under the flow of a cooling fluid . in one embodiment , the fins comprise a thin metal film , such as copper or aluminum , which is laminated to a thin polymeric layer . the polymeric layer provides resilience and elasticity to the metal film and the cooling fins .