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US 12,555,706 B2Granted
Over-current protection device
AssigneePolytronics Technology Corp.
InventorsCheng-Yu Tung, Chen-Nan Liu, Chia-Yuan Lee, Hsiu-Che Yen, Yung-Hsien Chang, Yao-Te Chang, Fu-Hua Chu
Life of this patent
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Abstract
An over-current protection device includes first and second electrode layers and a PTC material layer laminated therebetween. The PTC material layer includes a polymer matrix, and a conductive filler. The polymer matrix has a fluoropolymer. The total volume of the PTC material layer is calculated as 100%, and the fluoropolymer accounts for 47-62% by volume of the PTC material layer. The fluoropolymer has a melt viscosity higher than 3000 Pa·s.
Claims13
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 first fluoropolymer, wherein the total volume of the PTC material layer is calculated as 100%, and the first fluoropolymer accounts for 47% to 62% by volume of the PTC material layer, and the first fluoropolymer has a melt viscosity ranging from 3000 Pa·s to 5300 Pa·s at 240° C. and at a shear rate of 50 sec−1, wherein the first fluoropolymer is selected from the group consisting of a first polyvinylidene difluoride (PVDF), a second PVDF, and a combination thereof, wherein the first PVDF has a first melt viscosity and the second PVDF has a second melt viscosity, and the second melt viscosity is higher than the first melt viscosity;
- and
- a conductive filler dispersed in the polymer matrix, thereby forming an electrically conductive path in the PTC material layer.
4 more elements
Dependencies are inferred from the claim text.