Littelfuse Electronics (shanghai) Co., Ltd.

Littelfuse, Inc.

Yingsong Fu

Jianhua Chen

Zhiyong Zhou

Wei Jun Zheng

Chun-Kwan Tsang

Edward W Rutter, Jr

Cheng Hu

Mingjun Jin

A novel polymer positive temperature coefficient (PPTC) material, device, and method of fabrication. One example of polymer positive temperature coefficient (PPTC) includes a polymer matrix, the polymer matrix comprising a first polymer. The PPTC material may further include a conductive filler, disposed in the polymer matrix; and at least one polymer filler, dispersed within the polymer matrix. The at least one polymer filler may comprise a second polymer, different from the first polymer, wherein the at least one polymer comprises a first melting temperature, and wherein the second polymer comprises a second melting temperature, the second melting temperature exceeding the first melting temperature by at least 20 C.

PPTC composition and device having low thermal derating and low process jump

The present invention provides a conductive polymer composition, a conductive polymer sheet, an electrical device, and their preparation methods. The conductive polymer composition of the present invention includes a polymer and a conductive powder at a volume ratio of 35:65 to 65:35. The polymer includes at least one semicrystalline polymer selected from polyolefin, a copolymer of at least one olefin and at least one non-olefinic monomer copolymerizable therewith, and a thermoformable fluorine-containing polymer. The stated conductive powder includes at least one powder of a transition metal carbide, a transition metal carbon silicide, a transition metal carbon aluminide, and a transition metal carbon stannide. And the stated size distribution of the conductive powder satisfies: 20&#x3e;D/D&#x3e;6, where Ddenotes a corresponding particle size when a cumulative particle-size distribution percent in the conductive powder reaches 50%, and Ddenotes a maximum particle size. The stated conductive polymer composition has excellent processability, and can be used for preparing a PPTC device with ultralow resistance and stability in air without an oxygen barrier coating.

Conductive polymer composition, conductive polymer sheet, electrical device, and their preparation methods

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Shanghai, China

Yingsong Fu