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Download fileElectroless nickel bumping of aluminium bondpads. Part 1 - surface pre-treatment and activation
journal contribution
posted on 2008-10-22, 13:26 authored by David HuttDavid Hutt, Changqing LiuChangqing Liu, Paul ConwayPaul Conway, David Whalley, Samjid H. MannanElectroless nickel bumping of aluminum (Al) bondpads
followed by solder paste printing is seen as one of the lowest
cost routes for the bumping of wafers prior to flip-chip assembly.
However, the electroless nickel bumping of Al bondpads is not
straightforward and a number of activation steps are necessary to
enable the nickel deposit to form a strong, electrically conductive
bond with the Al. For the electroless nickel coating of mechanical
components made of aluminum, a zincate activation process has
been used for many years, however extension of these techniques
to semiconductor wafers requires careful control over these
pretreatments to avoid damage to the very thin bondpads. This
paper reports a number of experiments designed to characterize
the activation of Al bondpads to electroless nickel plating, focusing
on the effects of solution exposure time and bondpad composition.
In addition, the results are discussed in the context of other
studies presented in the literature to provide an understanding
of the mechanism of the zincate activation process applied to Al
bondpads.
History
School
- Mechanical, Electrical and Manufacturing Engineering
Citation
HUTT, D. A. ...et al, 2002. Electroless nickel bumping of aluminium bondpads. Part 1 - surface pre-treatment and activation. IEEE transactions on components and packaging technology, 25 (1), pp. 87-97Publisher
© Institute of Electrical and Electronics Engineers (IEEE)Publication date
2002Notes
This is a journal article. It was published in the journal IEEE transactions on components, packaging and manufacturing technologies [© IEEE], and is available from: http://ieeexplore.ieee.org/xpl/RecentIssue.jsp?punumber=6144. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.ISSN
1521-3331Language
- en