Plastic package structure for power element and its assembly method

PURPOSE: To provide a package structure for improving the high-frequency characteristics of an element, at the same time standardizing the assembly process for mass-production, and reducing the assembly cost of the element, and an element assembly method. CONSTITUTION: An assembly method includes a process for adhering a heat sink 7 to a lead frame 1, a process for eliminating a thermal stress that is generated from a power element chip 9 and the difference in a thermal coefficient of expansion, a process for manufacturing a lead for impedance matching to improve high-frequency characteristics and for shielding noises, and a process for performing plastic molding utilizing epoxy.