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Under Bump and Bond Metallization
As under bump and bond metallization (UBM) or over pad metallization (OPM), the electroless metal stack formation is providing a competitive metal applying technique compared to the conventionally used sputter technology. This cost efficient production technology is functioning as diffusion barrier for wire bonding application on Aluminum and Copper pads as well as solderable surface finish for flip chip application.
Chemistry
The unique Atotech electroless Nickel / Palladium / Gold surface finish, called XENOLYTE™, is applicable for wire bonding and soldering on the same surface. Palladium is providing an additional barrier into to achieve maximum pad protection for best reliability performance.
Equipment
Atotech's electroless metal deposition processes can be used on both major semiconductor equipment concepts – the fountain tool concept and the vertical processing concept. Corresponding information on the best known process conditions are the fundaments during the qualification and implementation at customer scale.
Advantages
The XENOLYTE™ electroless metal applying process is providing substantial benefits in terms of:
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Corrosion free surface finish | |
Highest solder joint and wire bond reliability | | Soldering and bonding on the same surface |
| Excellent layer uniformity |
| Compliant to RoHS/REACH/WEEE |
| Standard process for fast turnaround |
| Global presence of Atotech |
| XENOLYTE™ is providing higher reliability due to pad protection by applying a Nickel / Palladium / Gold metal stack. |
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| Atotech Testwafer for UBM/OPM |
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| Wire Bond on Xenolyte UBM |
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| Solder Balls on Xenolyte UBM |
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