Flash Temperature on the Asperity Scale and Scuffing

McCool, John I.; John, Jaison Jacob

doi:10.1115/1.3261709

Cited by 13 publications

(4 citation statements)

References 1 publication

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“…These models are based on the coefficient of friction which is difficult to measure accurately. This is one of the major drawbacks of these models and as a result they are difficult to implement as a scuffing criterion in a components design stage [25,37].…”

Section: Contact Temperature Calculationsmentioning

confidence: 99%

A review of scuffing models

Bowman

Stachowiak

1996

Tribol Lett

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The mechanism of wear known as scuffing has been a research topic of great interest for many years. However, the question of how scuffing is initiated and the factors that contribute to its occurrence are still poorly understood. In general, it can be said that scuffing manifests itself as the sudden failure of lubricating films in mechanical equipment operating under extreme conditions of load and/or speed. Components such as cams, tappets, gears and piston rings are all prone to scuffing failure. Understanding the mechanisms that initiate failure would enable the development of criteria for scuffing prediction. This paper reviews the numerous scuffing models and theories that exist today and, in doing so, defines the important factors involved in scuffing initiation. Emphasis is given to existing theoretical scuffing models which have been correlated by a wealth of research data obtained from experimental test rigs.

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Section: Contact Temperature Calculationsmentioning

confidence: 99%

A review of scuffing models

Bowman

Stachowiak

1996

Tribol Lett

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“…They used a quasi-steady-state approach to determine the distribution of asperity flash temperatures when rough surfaces undergo relative sliding. The average flash temperature expression of McCool and John (15) is used in this study to evaluate the contact temperature.…”

Section: Flash Temperature Modelmentioning

confidence: 99%

On the Microcontact Mechanism of Thermosonic Wire Bonding in Microelectronics: Saturation of Interfacial Phenomena

Jeng

Chen

2005

Tribology Transactions

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Thermosonic ball bonding is widely used in interconnections to integrated circuits. This work used a thermosonic bonding machine and a shear tester to study the effects of preload, preheat temperature, ultrasonic power, welding time, and wire diameters on shear force. The results reveal that shear force of thermosonic wire bonding can be elucidated from the viewpoint of interfacial microcontact phenomena such as energy intensity, interfacial temperature, and real contact area. As the energy intensity is increased, the shear force increases, reaches a maximum, and then decreases. The energy intensity at which the shear force reaches maximum is called the saturated energy intensity. After saturation (that is, the establishment of maximum atomic bonds), any additional energy input will damage the bonding, decreasing the shear force. The saturated energy phenomenon can be further confirmed by using wires with different diameters. It is also observed that the saturation phenomena, and thereby the optimal shear force, occurs under a certain range of interfacial temperature.

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“…Kuhlmann-Wilsdorf [21], using approximate curves of Jaeger and a curve-fitting method, developed approximate expressions of average temperature rise for a single heat source at plastically deformed contact spots. McCool and John [22] proposed a method based on the flash temperature approximation formulas developed by Kuhlmann-Wilsdorf [21]. They used a quasi-steady-state approach to determine the distribution of asperity flash temperatures when rough surfaces undergo relative sliding.…”

Section: Flash Temperature Modelmentioning

confidence: 99%

“…They used a quasi-steady-state approach to determine the distribution of asperity flash temperatures when rough surfaces undergo relative sliding. The method of calculating flash temperature by McCool and John [22] is used in this study to evaluate the contact temperature.…”

Section: Flash Temperature Modelmentioning

confidence: 99%

Thermosonic wire bonding of gold wire onto copper pad using the saturated interfacial phenomena

Jeng¹,

Aoh²,

Wang³

2001

J. Phys. D: Appl. Phys.

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Copper has been used to replace conventional aluminium interconnection to improve the performance of deep submicron integrated circuits. This study used the saturated interfacial phenomena found in thermosonic ball bonding of gold wire onto aluminium pad to investigate thermosonic ball bonding of gold wire onto copper pad. The effects of preheat temperatures and ultrasonic powers on the bonding force were investigated by using a thermosonic bonding machine and a shear tester. This work shows that under proper preheat temperatures, the bonding force of thermosonic wire bonding can be explained based on interfacial microcontact phenomena such as energy intensity, interfacial temperature and real contact area. It is clearly shown that as the energy intensity is increased, the shear force increases, reaches a maximum, and then decreases. After saturation, i.e. the establishment of maximum atomic bonding, any type of additional energy input will damage the bonding, decreasing the shear force. If the preheat temperature is not within the proper range, the interfacial saturation phenomenon does not exist. For a preload of 0.5 N and a welding time of 15 ms in thermosonic wire bonding of gold wire onto copper pads, a maximum shear force of about 0.33 N is found where the interfacial energy intensity equals 1.8×106 J m-2 for preheat temperatures of 150°C and 170°C. Moreover, the corresponding optimal ultrasonic power is about 110 units.

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Flash Temperature on the Asperity Scale and Scuffing

Cited by 13 publications

References 1 publication

A review of scuffing models

A review of scuffing models

On the Microcontact Mechanism of Thermosonic Wire Bonding in Microelectronics: Saturation of Interfacial Phenomena

Thermosonic wire bonding of gold wire onto copper pad using the saturated interfacial phenomena

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