Method for electroless gold deposition in the presence of a palladium seeder and article produced thereby
US6383617B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 10, 2000 |
| Grant date | May 7, 2002 |
| Priority date | — |
| Expiry date | Apr 10, 2020 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/24917
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
Gold is deposited on a copper base defining electrical circuit features disposed on a substrate containing a palladium seeder, by initially treating the substrate with an alkaline cleaner, followed by treating the substrate with sodium persulfate, and subsequently treating the substrate with a diluted sulfuric acid solution. The substrate is rinsed between each one of the treatments, and after the final rinse following treatment with diluted sulfuric acid, the substrate is immersed in a gold deposition solution whereby gold is deposited on the exposed surfaces of the copper circuit features on a substrate. The process embodying the present invention provides a method for depositing gold on high density copper conductor lines or pads, even in areas of the surface in which the conductors are spaced apart 2.0 mil or less, without cleaning or removing the palladium seed from the surface.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.