The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 23, 1993
Filed:
Dec. 20, 1991
Chin-Ching Huang, San Jose, CA (US);
VLSI Technology, Inc., San Jose, CA (US);
Abstract
An Au/si die attach method for attaching a die to a package including preheating the package, melting an Au/Si preform in the package cavity, scratching the die onto the package cavity to form a die attach bond, and gradually cooling an Au/Si die bond by reducing heat supplied to the package, so as to cool the package through a monotonically decreasing sequence of temperatures, wherein the package is maintained for a predetermined period of time at each temperature in the sequence. A heating block with segments supplies a decreasing amount of heat to the packages to let the die attached bond gradually cool. The packages are kept on top of the segments of the heating block for a predetermined period of time and each segment is heated to a specific temperature. The gradual cooling of the die attach bond decreases the thermal resistance and prevents the creation of voids in the die attach bond.