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:
Apr. 13, 1993
Filed:
Sep. 30, 1991
Rafael C Alfaro, The Colony, TX (US);
Lau B Howe, Subanq Java, MY;
Thomas H Ramsey, Garland, TX (US);
Texas Instruments Incorporated, Dallas, TX (US);
Abstract
An apparatus (10) and method is provided for bonding wire (12) to the bond sites (28) of integrated circuits (14). In preferred embodiments a bond end (30) on gold wire (12) is bonded to aluminum bond pad (28). Apparatus (10) includes a high frequency ultrasonic energy source (20) designed to provide ultrasonic energy at frequencies from about 100 kHz to about 125 kHz. The ultrasonic energy is imparted to the bonding interface (32) via transducer (18) and capillary (16). The transducer (18) is modified in length and tool clamp point (40) is sited on transducer (18) so that the high frequency ultrasonic energy is at the antinodal point in its application to interface (32) and thus is optimized. In preferred embodiments of the process, the ultrasonic energy is applied at about 114 kHz. In this fashion, the bond formed between bond end (30) and bond pad (28) is optimized in terms of shear strength, bonding time and processing temperatures. Particularly beneficial results are noticed with respect to aluminum alloy bond pads such as Al, 2% Cu, which have been particularly troublesome in terms of intermetallic formation and bond strength in the prior art. Thus according to the invention, the use of high frequency ultrasonic energy in the aforementioned range, results in superior strength bonds formed with greater processing parameter flexibility.