Metal fusion bonding – Process – Using high frequency vibratory energy
Patent
1991-09-30
1993-04-13
Ramsey, Kenneth J.
Metal fusion bonding
Process
Using high frequency vibratory energy
228 45, 228179, H01L 21607
Patent
active
052014541
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.
REFERENCES:
patent: 3054309 (1962-09-01), Elmore et al.
patent: 3641660 (1972-02-01), Adams et al.
patent: 3747198 (1973-07-01), Benson et al.
patent: 3776447 (1973-12-01), Adams et al.
patent: 3908886 (1975-09-01), Raske
patent: 4836883 (1989-06-01), Hatcher, Jr.
patent: 4842662 (1989-06-01), Jacobi
patent: 4854494 (1989-08-01), von Raben
patent: 4889274 (1989-12-01), Ramsey
"Very high energy ultrasonics" E. A. Neppiras, Special Article British Journal of Applied Physics vol. 11, Apr. 1960, pp. 143-150.
"Ultrasonics: An Aid to Metal Forming?", Langenecker et al., Metal Progress, vol. 85, Apr. 1964, pp. 97-101.
"Effects of Ultrasound on Deformation Characteristics of Metals," Langenecker, IEEE Transactions on Sonics and Ultrasonics, vol. SU-13, No. 1, Mar. 1966, pp. 1-8.
"A Note on the Effect of Ultrasonic Activation on Diffusion and Sintering", Hochman et al., International Journal of Powder Metallurgy, vol. 2, 1966, pp. 15-16.
"The Influence of Ultrasonic Energy on Kinetic Processes in Solids", Hayes et al., IEEE Journal on Sonics and Ultrasonics, vol. SU-16, No. 2, Apr. 1969, pp. 68-75.
"Intermetallic Formation in Gold-Aluminum Systems" E. Philofsky, Solid State Electronics, vol 13, 1970, pp. 1391-1399.
"High-Frequency Fatigue in Aluminum", Chevaller et al. J. Appl. Phys., vol. 43, No. 1, Jan. 1972, pp. 73-77.
"The Formation of Ultrasonic Bonds Between Metals", K. Joshi, Welding Journal, vol. 50, Dec. 1971, pp. 840-848.
"Metallurigical Failure Modes of Wire Bonds", G. Harman, 12th Annual Proceedings, Reliability Physics Symposium, Apr. 1974, pp. 131-141.
"Sonochemistry", K. Suslick, Science, vol. 247, Mar. 1990, pp. 1439-1445.
"Phenomenological Considerations in Ultrasonic Welding", Jones et al., Welding Research Supplement, Jul. 1961, pp. 289-305.
Alfaro Rafael C.
Howe Lau B.
Ramsey Thomas H.
Barndt B. Peter
Brady III W. James
Donaldson Richard L.
Ramsey Kenneth J.
Texas Instruments Incorporated
LandOfFree
Process for enhanced intermetallic growth in IC interconnections does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Process for enhanced intermetallic growth in IC interconnections, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Process for enhanced intermetallic growth in IC interconnections will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1149785