Over-current protection device
US9997906B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 21, 2017 |
| Grant date | Jun 12, 2018 |
| Priority date | — |
| Expiry date | Sep 21, 2037 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08L2207/062
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An over-current protection device comprises first and second electrode layers and a PTC material layer laminated therebetween. The PTC material layer has a resistivity less than 0.05 Ω·cm and comprises a polymer matrix, a conductive ceramic filler and a carbon-containing conductive filler. The polymer matrix comprises a fluoropolymer having a melting point higher than 150° C. and comprises 50-60% by volume of the PTC material layer. The conductive ceramic filler having a resistivity less than 500μΩ·cm is dispersed in the polymer matrix and comprises 40-45% by volume of the PTC material layer. The carbon-containing conductive filler is dispersed in the polymer matrix and comprises 0.5-5% by volume of the PTC material layer. At 25° C., a ratio of a hold current to an area of the over-current protection device is 0.21-0.3 A/mm2, and a ratio of an endurable power to the area of the over-current protection device is 4.8-7.2 W/mm2.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.