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.

A thermistor material and a method for preparing a thermistor material are provided. The thermistor material is prepared by mixing and heating a mixture containing BaTiO.sub.3, B.sub.2O.sub.3, SiO.sub.2, Li.sub.2O, P.sub.2O.sub.5, Cs.sub.2O, Nd.sub.2O.sub.3, Al.sub.2O.sub.3 and TiO.sub.2.

A semiconductor ceramic composition represented by formula (1),

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

wherein, A represents at least one element selected from Na and K, RE represents at least one element selected from Y, La, Ce, Pr, Nd, Sm, Gd, Dy and Er;

0.750y≦x≦1.50y  (2),

0.007≦y≦0.125  (3),

0≦(w+z)≦0.010  (4),

v+x+y+w=1  (5),

u+z=1  (6),

0.950≦m≦1.050  (7),

0.001 to 0.055 mol of Ca is contained, and 0.0005 to 0.005 mol of at least one selected from Mg, Al, Fe, Co, Cu and Zn is contained.

A semiconductor ceramic composition which is a BaTiO.sub.3 based semiconductor ceramic composition, wherein, part of Ba is replaced by at least A (at least one alkali metal element selected from Na and K), Bi and RE (at least one element selected from rare earth elements including Y), and part of Ti is replaced by at least TM (at least one element selected from the group including of V, Nb and Ta), the relationships of 0.7≦{(the content of Bi)/(the content of A)}≦1.43, 0.017≦{(the content of Bi)+(the content of A)}≦0.25, and 0<{(the content of RE)+(the content of TM)}≦0.01 are satisfied when the total content of Ti and TM is set as 1 mol, the grain sizes have a maximum peak in a grain size distribution in a range of 1.1 μm to 4.0 μm or less, and the distribution frequency of the peak is 20% or more.

In an embodiment an electrical component includes an electrical resistor having a PTC ceramic with a reference temperature exceeding 150° C., wherein, at the reference temperature, a reference resistance is twice an amount of a minimum resistance of the PTC ceramic.

In an embodiment a component includes at least one carrier layer, the carrier layer having a top side and a bottom side and at least one functional layer arranged on the top side of the carrier layer, the functional layer including a material having a specific electrical characteristic, wherein the component is configured for direct integration into an electrical system as a discrete component.

The present invention is directed to a varistor comprising a dielectric material comprising a sintered ceramic composed of zinc oxide grains and a grain boundary layer between the zinc oxide grains. The grain boundary layer contains a positive temperature coefficient thermistor material in an amount of less than 10 mol % based on the grain boundary layer.

A ceramic dielectric including: a bulk dielectric including barium (Ba) and titanium (Ti); a ceramic nanosheet; and a composite dielectric of the bulk dielectric and the ceramic nanosheet.

The present invention is directed to a varistor comprising a dielectric material comprising a sintered ceramic composed of zinc oxide grains and a grain boundary layer between the zinc oxide grains. The grain boundary layer contains a positive temperature coefficient thermistor material in an amount of less than 10 mol % based on the grain boundary layer.

A PTC thermistor element for a tempering device may include a main body, which may have a positive temperature coefficient. The main body may have PTC thermistor components, a core, and ceramics components at least in the core. The PTC thermistor components may have a positive temperature coefficient, and the ceramics components may have a thermal conductivity of at least 2.5 W/mK. The ceramics components may be disposed in a distributed manner.