Electroless deposition of nickel on a masked aluminum surface
US4122215A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 27, 1976 |
| Grant date | Oct 24, 1978 |
| Priority date | — |
| Expiry date | Dec 27, 1996 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC23C18/1844
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A method for depositing electroless nickel on aluminum or aluminum alloy is described. The method is particularly useful for fabricating bonding pads on aluminum metallized semiconductor devices and for creating beam leads. The described method deposits a thick nickel layer directly on aluminum without the use of intermediate layers or surface activation as required in the prior art. The method basically comprises immersion in a stop-etchant which simultaneously removes aluminum oxide and activates the surface; immersion in a solution which activates the aluminum with nickel ions and deactivates mask material; and immersion in a novel electroless nickel bath. A technique for electrolessly depositing gold is also described.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.