US 12,406,782 B2
Over-current protection device
Chen-Nan Liu, Pitou Township (TW); Yung-Hsien Chang, Douliu (TW); Hsiu-Che Yen, Taoyuan (TW); Cheng-Yu Tung, Tainan (TW); Chia-Yuan Lee, Hsinchu (TW); Yu-Chieh Fu, Hsinchu (TW); Yao-Te Chang, Linnei Township (TW); and Fu-Hua Chu, Taipei (TW)
Assigned to POLYTRONICS TECHNOLOGY CORP., Hsinchu (TW)
Filed by Polytronics Technology Corp., Hsinchu (TW)
Filed on Jan. 5, 2023, as Appl. No. 18/150,729.
Claims priority of application No. 111121004 (TW), filed on Jun. 7, 2022.
Prior Publication US 2023/0395287 A1, Dec. 7, 2023
Int. Cl. H01C 7/02 (2006.01); H01C 1/14 (2006.01)
CPC H01C 7/021 (2013.01) [H01C 1/1406 (2013.01)] 14 Claims
OG exemplary drawing
 
1. An over-current protection device, comprising:
a first electrode layer;
a second electrode layer; and
a positive temperature coefficient (PTC) material layer laminated between the first electrode layer and the second electrode layer, the PTC material layer comprising:
a polymer matrix comprising a fluorine-free polyolefin-based polymer and a fluoropolymer, wherein the total volume of the PTC material layer is calculated as 100%, and the fluorine-free polyolefin-based polymer accounts for 41-55% and the fluoropolymer accounts for 5-7% by volume of the PTC material layer;
a conductive filler dispersed in the polymer matrix, thereby forming an electrically conductive path in the PTC material layer; and
a titanium-containing inner filler dispersed in the polymer matrix, wherein the titanium-containing inner filler has a compound represented by a general formula (I):
MTiO3  (I)
wherein the M represents transition metal or alkaline earth metal, and the total volume of the PTC material layer is calculated as 100%, and the titanium-containing inner filler accounts for 1-9% by volume of the PTC material layer.