A varistor includes a sintered body, an internal electrode, an insulating layer, and an external electrode. The internal electrode is disposed in an interior of the sintered body. The insulating layer covers at least part of the sintered body and includes Zn.sub.2SiO.sub.4. The external electrode is electrically connected to the internal electrode, covers part of the sintered body and part of the insulating layer, and is in contact with the part of the insulating layer. The insulating layer has a region being in contact with the external electrode, the region having a greater average thickness than a region of the insulating layer which is out of contact with the external electrode.

The invention relates to a switch including a switch housing, a contact system and a base disposed in the switch housing, a resistive element for diagnosing a state of a switch, and at least two terminals leading from the base. The resistive element has a specific resistance value. The resistive element is a conductive material formed on the base, the terminals being electrically connected by the conductive material.

A thermistor has a thermistor element, a protective film, and an electrode portion. The protective film is formed of a SiO.sub.2 film having a film thickness in a range of 50 nm or more and 1000 nm or less. The protective film is formed in contact with the thermistor element. Alkali metal is unevenly distributed in a region including an interface between the thermistor element and the protective film.

The resistive material contains copper and manganese, an oxide film of manganese being formed on a surface of the resistive material.

A thermistor chip is provided, which includes a thermosensitive ceramic substrate, a surface electrode and a bottom electrode. The surface electrode and the bottom electrode are respectively arranged on the two surfaces of the thermosensitive ceramic substrate. The surface electrode is a silver layer. The bottom electrode consists of a silver layer, a titanium-tungsten alloy layer, a copper layer and a gold layer, laminating on the thermosensitive ceramic substrate in turn from inside to outside. A preparation method thereof is also provided. The thermistor chip can meet the requirements of both solder paste reflow soldering and wire bonding process simultaneously, and has the advantages of good bonding effect and high temperature resistance, high reliability and high stability.

A thermistor chip is provided, which includes a thermosensitive ceramic substrate, a surface electrode and a bottom electrode. The surface electrode and the bottom electrode are respectively arranged on the two surfaces of the thermosensitive ceramic substrate. The surface electrode is a silver layer. The bottom electrode consists of a silver layer, a titanium-tungsten alloy layer, a copper layer and a gold layer, laminating on the thermosensitive ceramic substrate in turn from inside to outside. A preparation method thereof is also provided. The thermistor chip can meet the requirements of both solder paste reflow soldering and wire bonding process simultaneously, and has the advantages of good bonding effect and high temperature resistance, high reliability and high stability.

A variable resistor according to the present invention includes a substrate, a resistive element disposed on a first surface of the substrate, oil that coats an upper surface of the resistive element, and a slide member that slides on the upper surface of the resistive element coated with the oil, wherein an output of the variable registor changes as a position at which the slide member makes contact with the resistive element changes. The variable resistor further includes an oil repellent part that surrounds at least a part of the resistive element in plan view viewed from above the first surface of the substrate, the oil repellant part having surface free energy smaller than that of the resistive element, whereby oil can be stably held on a resistive element surface without forming irregularities on the resistive element surface.

The present disclosure relates to a negative temperature coefficient product comprising an electrically conductive percolation network of printable NTC material as particles in a cross-linked dielectric polymer matrix and to a method of manufacturing thereof. The particles comprising a spinel phase, preferably a C-spinel phase, having a general formula M.sub.3O.sub.4 comprising at least a first metal M.sup.I that is manganese and second metal M.sup.II that is nickel. In addition the particles include a nickel oxide phase. The printable NTC material can be dispersed in a printable NTC ink comprising a dispersant, from which the NTC product, e.g. a thermistor, can be formed, e.g., after drying of the dispersant. During processing the ink is kept at a temperature below 300° C. Optionally, the spinel phase comprises a further metal M.sup.III. The weight fraction of nickel oxide with respect to the overall mass of the printable NTC material is preferably in a range between one and twenty weight percent.

To provide a thick film resistor paste for a resistor having no abnormalities of cracks in appearance and sufficient surge resistance, especially for low resistance, while using lead borosilicate glass, a thick film resistor using the thick film resistor paste, and an electronic component provided with the thick film resistor. A thick film resistor paste comprises a ruthenium-oxide-containing glass powder and an organic vehicle, the ruthenium-oxide-containing glass powder comprises 10 to 60 mass % of ruthenium oxide, a glass composition of the ruthenium-oxide-containing glass powder comprises 60 mass % or less of silicon oxide, 30 to 90 mass % of lead oxide, 5 to 50 mass % of boron oxide relative to 100 mass % of glass components, and, a combined amount of silicon oxide, lead oxide and boron oxide by mass % is 50 mass % or more relative to 100 mass % of the glass components.

The present invention relates to a polymer voltage-dependent resistor (PVDR) in various physical forms and methods for manufacturing the varistor. The body of the PVDR is composed of a polymer matrix having a filler composed of doped zinc oxide particles, other semi conductive particles or metal particles uniformly distributed therein. Conductive electrodes may be affixed to the polymer matrix and electrical leads attached to the electrodes.