A semiconductor ceramic composition may include, as a main component, a BaTiO.sub.3-based compound according to the formula [Ba.sub.bCa.sub.cSr.sub.sPb.sub.pR.sub.x][Ti.sub.tA.sub.aMn.sub.m]O.sub.3+z. R may represent at least one element selected from a group consisting of Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, and Yb. A may represent at least one element selected from a group consisting of V, Nb, and Ta. The variables b, c, s, p, x, t, a, m, and z may be defined as: b=1cspx; 0<c+s+p<0.51; 0.490<b<0.999; 0.0<c<0.5; 0.0<s<0.5; 0.05<p<0.5; 0.001<x<0.01; 1.0001<(t+a+m)<1.011575; 0.9889<t<1.000375; 0.00010<a<0.0012; 0.0001<m<0.01; and 0.0001<z<0.01.

A barium titanate based PTC thermistor ceramic composition without using Pb. Its Curie temperature is shifted to a temperature higher than 120 C. The PTC thermistor can readily turn semiconductive even if it is sintered in air. The resistivity at 25 C. is low and the variation rate of the resistivity at 25 C. with time is little. The PTC thermistor ceramic composition includes a sintered body having a barium titanate based compound represented by formula (1) as the main component, (Ba.sub.1-x-y-wBi.sub.xA.sub.yRE.sub.w).sub.(Ti.sub.1-zTM.sub.z)O.sub.3 (1), wherein, 1.02yx1.5y (2), 0.007y0.125 (3), 0(w+z)0.01 (4), 0.971.06 (5), and the sintered body contains Ca in a ratio of 0.01 mol or more and less than 0.05 mol relative to 1 mol of Ti site in terms of element.

A dielectric ceramic composition includes a main component comprising (1-x)BaTiO.sub.3-x(Na.sub.1-yK.sub.y)NbO.sub.3, where 0.005x0.5 and 0.3y1.0; a first subcomponent comprising an element selected from the group consisting of Mn, V, Cr, Fe, Ni, Co, Cu and Zn; and a second subcomponent comprising SiO.sub.2.

A semiconductor ceramic composition including a compound represented by the following general formula (1) as a main component.

(Ba.sub.vBi.sub.xA.sub.yRE.sub.w).sub.m(Ti.sub.uTM.sub.z)O.sub.3 (1)

(wherein, A represents both elements of Na and K; RE is at least one element selected from the group consisting of Y, La, Ce, Pr, Nd, Sm, Gd, Dy and Er; and TM is at least one element selected from the group consisting of V, Nb and Ta.)

0.01x0.15 (2)

xy0.3 (3)

0(w+z)0.01 (4)

v+x+y+w=1 (5)

u+z=1 (6)

0.950m1.050 (7)

further, 0.001 mol to 0.055 mol of Ca is included and the ratio of Na/(Na+K) is 0.1 or more and less than 1.

A macromolecule-based conductive composite material and a PTC element. The macromolecule-based conductive composite material comprises: a macromolecule base material, having a volume fraction of the macromolecule base material of 20%-75%; a conductive filler with a core-shell granule structure and dispersed in the macromolecule base material, having a volume fraction of 25%-80%; and a coupling agent, being a titanate coupling agent and accounting for 0%-5% of the volume of the conductive filler. The PTC element prepared by using the macromolecule-based conductive composite material comprises at least two metal electrode plates (12, 12), a macromolecule-based conductive composite material (11) being closely combined with the metal electrode plates (12, 12). The PTC element prepared from the macromolecule-based conductive composite material has the advantages of low room-temperature resistivity, outstanding weather durability, good voltage resistance and good resistor repeatability.

The present disclose provides a sol-gel paste composition of matter that is provided for application to a substrate to form an electrically conductive coating which can be used, for example, as a resistor in a thick-film resistive heater, which a positive temperature coefficient of resistivity (PTCR) as a consequence of the electronic properties of the electrically conductive semiconductors used in the resistor layer and which exhibits self-limiting behavior at elevated temperatures. The composition includes a sol gel solution in which up to 90% by weight (wt. %) of the solution is comprised of conductive and insulative powders in a uniform stable solution.

A positive temperature coefficient (PTC) heater is disclosed. In an embodiment the PTC heater includes a main body having a length L, a width B, and a height H made of a PTC material and a first electrode and a second electrode made of an electrically conductive material, wherein the following is true for L, B, and H: LBH, and wherein the electrodes are connected to the main body so that the following is true for a spacing d thereof from one another: d>H.

This disclosure refers to a method for confectioning resistors that each comprise a PTC ceramic plate and metallic electrode layers covering opposite faces of the ceramic plate, said method comprising the following steps: measuring an electrical resistance of a resistor to be confectioned by applying an electrical potential to one of electrode layers such that an electric current flows from one of the electrode layers through the ceramic plate to the electrode layer on the opposite face of the ceramic plate, comparing the measured resistance to a target resistance, and removing, if the measured resistance is lower than the target resistance, a section of at least one of the electrode layers. This disclosure also refers to such a resistor and a heating device comprising such resistors.

Provided are a thermistor element including a conductive intermediate layer that can stably exist even at high temperature, and a method for manufacturing the same. The thermistor element includes: a thermistor element body 2 which contains an oxide thermistor material whose crystal structure is a perovskite-type; a conductive intermediate layer 3 formed on the thermistor element body; and an electrode layer 4 formed on the conductive intermediate layer, wherein the conductive intermediate layer is a composite oxide containing Mn. The method for manufacturing the thermistor element includes an intermediate layer forming step of forming a conductive intermediate layer of a composite oxide containing Mn on a thermistor element body, and an electrode layer forming step of forming an electrode layer on the conductive intermediate layer, wherein in the intermediate layer forming step, a Mn-containing dispersion is applied onto the thermistor element body, and dried to form a temporary intermediate layer.

The present disclose provides a sol-gel paste composition of matter that is provided for application to a substrate to form an electrically conductive coating which can be used, for example, as a resistor in a thick-film resistive heater, which a positive temperature coefficient of resistivity (PTCR) as a consequence of the electronic properties of the electrically conductive semiconductors used in the resistor layer and which exhibits self-limiting behavior at elevated temperatures. The composition includes a sol gel solution in which up to 90% by weight (wt. %) of the solution is comprised of conductive and insulative powders in a uniform stable solution.