Abstract
We present a study on optimization of pretreatment process of the electroless plating to obtain good aspect and process steadiness of nickel UBM on different aluminum surface morphology. Pitch 250um and circular Al pads with 85um opening in the passivation layer were prepared for our study. Six kinds of aluminum pads were produced by the sputtering system: Varian-3180. The compounds of the Al targets were 98.95%Al-l%Si-0.05%Ti in the Varian sputtering system and some set parameters of sputtering system were varied, the heterogeneous surface morphology of aluminum samples was gained in our research. All the samples underwent the electroless zinc/nickel/gold plating with tow kinds of different pretreatments. The effect of aluminium surface morphology on the nickel UBM was observed. The results demonstrated that the preircatment of Al pad surface by heat sodium hydroxide and mixed acid provided denser zinc seeds. That led to better electroless nickel plating. The reasonable and acceptable pretreatment of Al pad surface is critical for the nickel UBM.
| Original language | English |
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| Title of host publication | International Conference on Solid-State and Integrated Circuits Technology Proceedings, ICSICT |
| Pages | 603-606 |
| Number of pages | 4 |
| Publication status | Published - 1 Dec 2004 |
| Externally published | Yes |
| Event | 2004 7th International Conference on Solid-State and Integrated Circuits Technology Proceedings, ICSICT 2004 - Beijing, China Duration: 18 Oct 2004 → 21 Oct 2004 |
Conference
| Conference | 2004 7th International Conference on Solid-State and Integrated Circuits Technology Proceedings, ICSICT 2004 |
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| Country/Territory | China |
| City | Beijing |
| Period | 18/10/04 → 21/10/04 |
Keywords
- Electroless plating
- Flip-chip
- Micro-etch
- UBM
ASJC Scopus subject areas
- General Engineering