Wire bonding has been used in integrated circuit packaging for many decades because of its high reliability and performance. The most common metal used has been gold, but with the surge in commodity prices of gold in recent years, copper wire is now used to altered gold wire for cost saving. Many challenges have to be solved to meet its application requirement; coating is one of the applications.
In this study, a 3D coated copper wire and coated Al pad is built by finite element method to simulate ultrasonic bonding and thermosonic bonding. To consider the effect of coated material to stress and strain field on ultrasonic bonding and the effect of coated material to temperature field on thermosonic bonding. Then use the Taguchi experiment method to discuss the effect on Cu-Ball and Al pad under different coated material and thickness combination.
The results show that with coated material on Al pad or copper wire could reduce more than 48% of effective plastic strain after the bonding process, it obviously reduce the Al splash phenomenon in copper wire bonding. But the coated material such like palladium and nickel which have lower thermal conductivity would resist the heat transfer. And the Taguchi experiment method shows that the most effective way to reduce the effective stress during impact stage and ultrasonic vibration stage is to increase the thickness of palladium and nickel respectively, and when the thickness of coated material Au reached 0.01£gm could increase the temperature of Cu-Ball and Al pad mostly.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0904112-020258 |
| Date | 04 September 2012 |
| Creators | Jhuang, Yun-Da |
| Contributors | Chung-Ting Wang, Chi-Hui Chien, Ting-Nung Shiau, Jung-Hung Sun |
| Publisher | NSYSU |
| Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
| Language | Cholon |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0904112-020258 |
| Rights | user_define, Copyright information available at source archive |
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