Patent ID: 6873244

Claim:
A surface mountable laminated heat sensitive impedance device comprising: a first electrode layer comprising a first means and a second means and being electrically insulated between therein; an electrically insulating layer disposed under said first electrode layer; a first conductive layer disposed under said electrically insulating layer and comprising a first conductive part and a second conductive part and being electrically insulated between therein; a first conductive means being interposed between said first conductive part of said first conductive layer and said second means of said first electrode to allow said first conductive part of said first conductive layer to extend through said electrically insulating layer and conductive with said second means of said first electrode; a second conductive means interposed between said second conductive part of said first conductive layer and said first means of said first electrode to allow said second conductive part of said first conductive layer to extend through said electrically insulating layer and being conductive with said first means of said first electrode; a PTC conductive polymer disposed under said first conductive layer; a second electrode layer comprising a first means and a second means and being electrically insulated between therein; the distance between said first means of said second electrode and said second means of said second electrode being greater than the thickness of said PTC conductive polymer; and the minimum distance between said first means of said second electrode and said first conductive part of said first conductive layer and the minimum distance between said second means of said second electrode and said second conductive part of said first conductive layer are both less than the distance between said first means of said second electrode and said second means of said second electrode; a third conductive means extending through said PTC conductive polymer and said electrically insulating layer to allow said first means of said second electrode layer to be conductive with said first means of said first electrode layer; and a fourth conductive means extending through said PTC conductive polymer and said electrically insulating layer to allow said second means of said second electrode layer to be conductive with said second means of said first electrode layers, wherein the first conductive means and the third conductive means are separated, and the second conductive means and the fourth conductive means are separated.