Sequential electrodeposition of metals using modulated electric fields for manufacture of circuit boards having features of different sizes
US6309528A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 18, 1999 |
| Grant date | Oct 30, 2001 |
| Priority date | — |
| Expiry date | Oct 18, 2019 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31678
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
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.