Electrodeposition without internal deposit stress
US4786376A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 5, 1988 |
| Grant date | Nov 22, 1988 |
| Priority date | — |
| Expiry date | Jan 5, 2008 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC25D1/00
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
An apparatus and method are described for electrodepositing an electroform with near zero internal stress. A voltage controlled power supply supplies current to both a mandrel, upon which a primary electroform is deposited, and to a deformable thin disk substrate, upon which a secondary deposit is formed. A strain gage on the deformable substrate measures any deformation caused by internal stress in the secondary deposit. The strain gage is connected to a strain gage transducer to produce an output signal to a proportional controller. The proportional controller in turn supplies a strain-proportional voltage signal to the power supply. A current mask ensures an even current density over the mandrel. After initially adjusting electroforming bath parameters to provide a zero internal stress in the starting electroform, the output from the strain gage causes proportional changes in the bath current to the mandrel to maintain a constant near zero internal stress in the primary electroform.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.