Over-current protection device
US7286038B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 18, 2007 |
| Grant date | Oct 23, 2007 |
| Priority date | — |
| Expiry date | Jan 18, 2027 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01C7/021
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An over-current protection device comprises two metal foils and a positive temperature coefficient (PTC) material layer laminated between the two metal foils. The PTC material layer includes: (1) a polymer substrate, being 35-60% by volume of the PTC material layer and including a fluorine-containing crystalline polymer with a melting point higher than 150° C., e.g., polyvinylidine fluoride (PVDF); and (2) a conductive ceramic filler (e.g., titanium carbide) distributed in the polymer substrate. The conductive ceramic filler is 40-65% by volume of the PTC material layer, and has a volume resistivity less than 500 μΩ-cm. The volume resistivity of the PTC material layer is less than 0.1 Ω-cm, and the ratio of the hold current of the PTC material layer at 25° C. to the area of the PTC material layer is between 0.05 and 0.2 A/mm2.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.