Abstract: A heat sink has a base and multiple fins. The fins are attached to the base, and each fin has a radiating surface and a conducting surface. The conducting surface is formed on the radiating surface and has at least one side abutting the base. The base is attached to an integrated circuit to dissipate heat from the integrated circuit. Because at least one of the two sides of the conducting surfaces is in full contact with the base, more heat is conducted from the base to the fins. Therefore the heat sink can cool the integrated circuit effectively.

Abstract: A method for detecting the inclined status of a hot plate comprising selecting a sensitive photoresist coated on a wafer. A first wafer is positioned on a standard hot plate to perform a bake treatment. A stepping exposure with gradually changing light intensity is performed to obtain the minimum exposure energy of the thickness of the first photoresist layer. A second photoresist layer the same as the first wafer is coated on the surface of the second wafer, and positioned on a hot plate under test to perform a bake treatment. The second photoresist layer is exposed by a minimum exposure energy, thereby having the first photoresist layer being uniformly exposed or not to determine whether the hot plate under test is inclined or not.