Patent ID: 6559670
Filing Date: 2003-05-06
Classification: G01R,H01L

Abstract:
A method for testing an integrated circuit chip, comprising:providing the integrated circuit chip, the integrated circuit chip comprising a top side and a back side, wherein the top side of the integrated circuit chip comprises a plurality of dielectrically spaced contacts electrically coupled to said integrated circuit chip, wherein the integrated circuit chip is housed in a package such that the backside of the integrated circuit chip is exposed; applying a liquid crystal to the back side of the integrated circuit chip; applying voltage and current to the integrated circuit chip; applying heat to the integrated circuit package such that the temperature of the integrated circuit chip rises above the state transition temperature of the liquid crystal; and optically inspecting the liquid crystal on the backside of the integrated circuit chip while the voltage and current are applied to the integrated circuit chip, wherein the temperature of the integrated circuit chip is lowered below the state transition temperature of the crystal while optically inspecting the liquid crystal.