Texas Instruments Corporation

Thomas H Ramsey

Rafael C Alfaro

Roger J Stierman

Richard M Brook

James F Haefling

K Gail Heinen

Lau B Howe

A method for electrically connecting integrated circuit copper-gold ball bond that connect a bond wire (18) with a bond pad (14) forms a palladium layer (16) in the electrical connection between the bond wire (18) and the bond pad (14). The connection avoids excessive stresses that arise from intermetallic formations between the bond wire (18) and the bond pad (14).

Method for obtaining metallurgical stability in integrated circuit

An (10) and method is provided for bonding wire (12) to the bond sites (28) of integrated circuits (14). In preferred embodiments 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 above about 125 kHz. The ultrasonic energy is imparted to the bonding interface (32) via transducer (18) and capillary (16). The transducer is modified in length and tool clamp point (40) is sited on transducer (18) so that the wavelength of the high frequency ultrasonic energy is at the antinodal point in its application to interface (32) and thus is optimized. In the preferred embodiments of the process the ultrasonic energy is applied at about 350 kHz at ambient temperature. 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% copper, which were 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, superior strength bonds are formed with greater processing parameter flexibility.

Ultrasonic bonding process beyond 125 kHz

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.

Process for enhanced intermetallic growth in IC interconnections

The disclosure relates to an electrical connection between a bonding pad on a semiconductor chip and a wire wherein the bonding pad is formed of copper doped aluminum and the wire is formed of copper doped gold. The wire has from about 100 to about 10,000 parts per million copper and the pad has from about 5000 to about 50,000 parts per million copper.

Semiconductor integrated circuit chip interconnections and methods

A substrate for mounting a flip-chip on a metallized circuit on the upper surface of the substrate. The substrate is silicon carbide condensed on a graphite or silicon core. The upper surface of the silicon carbide has a layer of insulating material comprised of silicon oxide, silicon nitride, aluminum nitride, boron nitride, an organic insulator such as polyimide, and diamond. The insulator prevents inadvertent shorting of the integrated circuit. The insulating layer can be deposited on the silicon carbide by such processes as chemical vapor deposition, sputtering, spinning or roller coating.

Insulated substrate for flip-chip integrated circuit device

The disclosure relates to the use of metastable state of mixed gases which, when appropriately mixed, provide better control of current and voltage conditions and subsequent arc formation properties in making balls of aluminum, copper and gold with an electronic flame-off method. The specific mixtures involve inert argon mixed with small amounts of hydrogen and neon. Exceptionally well controlled balls of uniform size result.

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Garland, TX, United States of America

Thomas H Ramsey