Jeffrey Bereth Hume

US Patent:

7608485, Oct 27, 2009

Filed:

Sep 8, 2006

Appl. No.:

11/530276

Inventors:

Sam-Hyo Hong - Spänga, SE
Henrik Hoyer - Los Gatos CA, US
Jeffrey Hume - El Granada CA, US

Assignee:

Infineon Technologies AG - Munich

International Classification:

H01L 21/00

US Classification:

438125, 257707, 257E33075

Abstract:

In a circuit, an integrated circuit package and methods for attaching integrated circuit dies or discrete power components to flanges of integrated circuit packages, each of the integrated circuit dies is sawed from a wafer. The thickness of the wafer is reduced by mechanical grinding, applying an isotropic wet chemical etching to the wafer to eliminate crystal defects, evaporating adhesion and diffusion barrier metals on the backside of the wafer, evaporating Au and Sn on the backside of the wafer, wherein the weight proportion of Au is equal to or larger than 85%, sawing the wafer into the circuit dies, and soldering each of the circuit dies to a respective flange of an integrated circuit package.