Process for forming device comprising metallized magnetic substrates
US6153078A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 5, 1999 |
| Grant date | Nov 28, 2000 |
| Priority date | — |
| Expiry date | Aug 5, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01F17/0033
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The invention provides an improved process for fabricating devices containing metallized magnetic ceramic material, such as inductors, transformers, and magnetic substrates. In particular, the unique vias utilized in the process of the invention allow fabrication of devices from multiple unfired ferrite layers with only a single via-coating step, thereby avoiding the need numerous punching steps. Moreover, there is no need for expanding the dimensions of the vias and thus no need for internal metallization. The invention therefore provides for green tape-type fabrication of devices such as inductors, transformers, and magnetic substrates in a manner faster, less complex, and more reliable than current methods. The invention also relates to use of an improved conductive material in such a process, the conductive material containing silver/palladium particles, ferrite particles, a cellulose-based or other organic binder, and a solvent. After firing of the substrate onto which the ink has been coated, and plating of copper thereon by a copper pyrophosphate bath, the plated copper exhibits a pull strength greater than about 4 kpsi, advantageously greater than about 5 kpsi. Use of a cop…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.