Patent ID: 6593844
Filing Date: 2003-07-15
Classification: H01C

Abstract:
A chip polymer PTC thermistor comprising:a conductive polymer having PTC properties; a first outer electrode in contact with said conductive polymer; a second outer electrode sandwiching said conductive polymer with said first outer electrode; one or more inner electrode disposed in between and parallel to said first and second outer electrodes, said one or more inner electrode being sandwiched by said conductive polymer; a first electrode directly electrically coupled with said first outer electrode; and a second electrode disposed electrically independently from said first electrode; wherein, when defining an inner electrode placed at the most adjacent to said first outer electrode as â€œoneâ€ , and defining a â€œnâ€ th inner electrode counting from the â€œoneâ€  as a â€œnâ€ th inner electrode, odd-numbered inner electrodes are directly coupled with said second electrode and even-numbered inner electrodes, with said first electrode, and when the total number of said inner electrodes is an odd number, said second outer electrode is electrically directly coupled with said first electrode, whereas when it is an even number, coupled with said second electrode; wherein, defining a distance from said odd-numbered inner electrode to said first electrode, or from said even-numbered inner electrode to said second electrode as â€œaâ€ , and a distance between the adjacent inner electrodes among said inner electrodes, or a distance between the inner electrode adjacent to said first outer electrode, or said second outer electrode, and said first outer electrode, or said second outer electrode, as â€œtâ€ , a ratio a/t is within a range 3-6, and wherein said ratio a/t is increased by maintaining â€œtâ€  and increasing â€œaâ€  in order to increase resistance of said thermistor.