Sequential electrodeposition of metals using modulated electric fields for manufacture of circuit boards having features of different sizes
US6652727B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 26, 2002 |
| Grant date | Nov 25, 2003 |
| Priority date | — |
| Expiry date | Apr 26, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05K2203/1492
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A continuous layer of a metal is electrodeposited onto a substrate having both hydrodynamically inaccessible recesses and hydrodynamically accessible recesses on its surface by a two-step process in which the hydrodynamically inaccessible recesses are plated using a pulsed reversing current with cathodic pulses having a duty cycle of less than about 50% and anodic pulses having a duty cycle of greater than about 50% and the hydrodynamically accessible recesses are then plated using a pulsed reversing current with cathodic pulses having a duty cycle of greater than about 50% and anodic pulses having a duty cycle of less than about 50%.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.