The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 23, 2007
Filed:
Jan. 18, 2007
David Shau Chew Wang, Taipei, TW;
Jyh Ming Yu, Kaohsiung, TW;
David Shau Chew Wang, Taipei, TW;
Jyh Ming Yu, Kaohsiung, TW;
Polytronics Technology Corporation, Hsinchu, TW;
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/mm.