US 11,990,258 B2
Over-current protection device
Hsiu-Che Yen, Taoyuan (TW); Yung-Hsien Chang, Douliu (TW); Cheng-Yu Tung, Tainan (TW); Chen-Nan Liu, Changhua County (TW); Chia-Yuan Lee, Hsinchu (TW); Yu-Chieh Fu, Hsinchu (TW); Yao-Te Chang, Yunlin County (TW); and Fu-Hua Chu, Taipei (TW)
Assigned to POLYTRONICS TECHNOLOGY CORP., Hsinchu (TW)
Filed by POLYTRONICS TECHNOLOGY CORP., Hsinchu (TW)
Filed on Sep. 28, 2022, as Appl. No. 17/954,596.
Claims priority of application No. 111121000 (TW), filed on Jun. 7, 2022.
Prior Publication US 2023/0395288 A1, Dec. 7, 2023
Int. Cl. H01C 7/02 (2006.01); H01C 1/14 (2006.01); H02H 9/02 (2006.01)
CPC H01C 7/027 (2013.01) [H01C 1/1406 (2013.01); H01C 7/021 (2013.01); H02H 9/026 (2013.01)] 10 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 fluoropolymer;
a conductive filler dispersed in the polymer matrix, thereby to forming an electrically conductive path in the PTC material layer; and
a titanium-containing dielectric filler dispersed in the polymer matrix, wherein the titanium-containing dielectric filler has a compound represented by a general formula (I):
MTiO3   (I)
wherein the M represents alkaline earth metal, and the titanium-containing dielectric filler is selected from the group consisting of BaTiO3, SrTiO3, CaTiO3, and any combination thereof,
wherein the total volume of the PTC material layer is calculated as 100%, and the titanium-containing dielectric filler accounts for 5-15% by volume of the PTC material layer, and
wherein the over-current protection device has an electrical resistivity ranging from 0.0136Ω·cm to 0.0211Ω·cm, and an endurable power per unit area ranging from 5.94 W/mm2 to 7.00 W/mm2.