Details
| Original language | English |
|---|---|
| Pages (from-to) | 58-66 |
| Number of pages | 9 |
| Journal | Journal of Materials Processing Technology |
| Volume | 258 |
| Early online date | 20 Mar 2018 |
| Publication status | Published - Aug 2018 |
Abstract
Real-time observations of the artificially increased oxide layer during the ultrasonic (US) bonding process were carried out to reveal the self-cleaning mechanisms. After the normal force loading, cracks occurred in the Al2O3 layer at the peripheral region of the wire/substrate interface and were perpendicular to the wire direction. As the US vibration started, the oxides started to detach from the pure metal surface and moved towards the middle of the contact area. With further vibration cycles, these detached oxides were milled from flakes into small particles. Due to three mechanisms including penetration, oxide flow and pushing, the small oxide particles were transported to the peripheral contact region or the outside of the contact area. When a metal splash existed, the flowing out of large amounts of oxides was facilitated. Pre-deformation originates cracks; vibration plays a significant role in detachment, milling, penetration and oxide flow; while the plastic deformation induced material flow is more critical on removing the oxides from the substrate by pushing. The shear tests showed that a 50 nm oxide coating could significantly enhance the Al-glass bonding strength by 2∼3 times.
Keywords
- Oxide removal process, Self-cleaning mechanisms, Transportation mechanisms, Ultrasonic wire bonding
ASJC Scopus subject areas
- Materials Science(all)
- Ceramics and Composites
- Computer Science(all)
- Computer Science Applications
- Materials Science(all)
- Metals and Alloys
- Engineering(all)
- Industrial and Manufacturing Engineering
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In: Journal of Materials Processing Technology, Vol. 258, 08.2018, p. 58-66.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Self-cleaning mechanisms in ultrasonic bonding of Al wire
AU - Long, Yangyang
AU - Dencker, Folke
AU - Isaak, Andreas
AU - Hermsdorf, Jörg
AU - Wurz, Marc
AU - Twiefel, Jens
N1 - Publisher Copyright: © 2018 Elsevier B.V. Copyright: Copyright 2018 Elsevier B.V., All rights reserved.
PY - 2018/8
Y1 - 2018/8
N2 - Real-time observations of the artificially increased oxide layer during the ultrasonic (US) bonding process were carried out to reveal the self-cleaning mechanisms. After the normal force loading, cracks occurred in the Al2O3 layer at the peripheral region of the wire/substrate interface and were perpendicular to the wire direction. As the US vibration started, the oxides started to detach from the pure metal surface and moved towards the middle of the contact area. With further vibration cycles, these detached oxides were milled from flakes into small particles. Due to three mechanisms including penetration, oxide flow and pushing, the small oxide particles were transported to the peripheral contact region or the outside of the contact area. When a metal splash existed, the flowing out of large amounts of oxides was facilitated. Pre-deformation originates cracks; vibration plays a significant role in detachment, milling, penetration and oxide flow; while the plastic deformation induced material flow is more critical on removing the oxides from the substrate by pushing. The shear tests showed that a 50 nm oxide coating could significantly enhance the Al-glass bonding strength by 2∼3 times.
AB - Real-time observations of the artificially increased oxide layer during the ultrasonic (US) bonding process were carried out to reveal the self-cleaning mechanisms. After the normal force loading, cracks occurred in the Al2O3 layer at the peripheral region of the wire/substrate interface and were perpendicular to the wire direction. As the US vibration started, the oxides started to detach from the pure metal surface and moved towards the middle of the contact area. With further vibration cycles, these detached oxides were milled from flakes into small particles. Due to three mechanisms including penetration, oxide flow and pushing, the small oxide particles were transported to the peripheral contact region or the outside of the contact area. When a metal splash existed, the flowing out of large amounts of oxides was facilitated. Pre-deformation originates cracks; vibration plays a significant role in detachment, milling, penetration and oxide flow; while the plastic deformation induced material flow is more critical on removing the oxides from the substrate by pushing. The shear tests showed that a 50 nm oxide coating could significantly enhance the Al-glass bonding strength by 2∼3 times.
KW - Oxide removal process
KW - Self-cleaning mechanisms
KW - Transportation mechanisms
KW - Ultrasonic wire bonding
UR - http://www.scopus.com/inward/record.url?scp=85044479558&partnerID=8YFLogxK
U2 - 10.1016/j.jmatprotec.2018.03.016
DO - 10.1016/j.jmatprotec.2018.03.016
M3 - Article
AN - SCOPUS:85044479558
VL - 258
SP - 58
EP - 66
JO - Journal of Materials Processing Technology
JF - Journal of Materials Processing Technology
SN - 0924-0136
ER -