Abstract: A spark plug having a discharge portion formed of a noble-metal chip, the spark plug being capable of restraining wear observed on a slenderized discharge portion in particular. Discharge portion 31 includes noble-metal chip 31′. Dimension D is 0.3-0.8 mm; and H is 0.4-2 mm, where D (mm) is a diameter representing the outside diameter of the noble-metal chip, and H (mm) is a discharge portion thickness representing the shortest distance between the periphery of a discharge face 31t and a corresponding end edge of a weld zone W where a center electrode 3 and the noble-metal chip 31′ are welded. Further, the noble-metal chip 31′ contains a predominant amount of Ir and 0.5-8% by weight Ni.

Abstract: A cutting tool coated with diamond in which diamond is coated as a film on a substrate having a step 15 to 500 &mgr;m in height in the vicinity of a cutting edge on the rake surface and/or the flank surface. Only the diamond film in the vicinity of the cutting edge can be polished first, without polishing the film of the diamond formed centrally of the rake surface and/or the flank surface. This enables the maximum effect (sharpening of the cutting edge and prevention of welding formation at cutting edge) to be realized with the necessary minimum polishing (with a decreased polishing removal), without setting special conditions and which is suited as a finishing tool.

Abstract: A solid electrolyte layer or body capable of being co-fired with an insulating ceramic substrate or body to be used as a gas sensor laminate. The gas sensor laminate is preferably composed of an alumina substrate (1) and an oxygen-ion conductive solid electrolyte layer (6) bonded to the alumina substrate (1) by firing. The oxygen-ion conductive solid electrolyte layer or body is formed from partially or wholly stabilized zirconia, which layer contains alumina in an amount of 10% to 80% by weight, particularly 30% to 75% by weight. In this manner, another ceramic layer; particularly, a ceramic layer (7)-of alumina can further be bonded to the oxygen-ion conductive solid electrolyte layer. The relative density of the ceramic layer can be 60% to 99.5%, preferably 80% to 99.5%.

Abstract: A heater has a cylindrical metallic shell, a heater body partly disposed in a front end portion of the metallic shell, an electrode disposed in a rear portion of the metallic shell and electrically connected to the heater body, and a terminal adapted to be capped with an electric connector. The terminal includes a terminal body for power supply to the heater body through the electrode and an engaging portion formed on an outer circumferential surface of the terminal body so as to be engageable with the electric connector. The electrode and the terminal body are formed integrally with each other. Such a heater can maintain good electrical conduction from the terminal to the heater body with its simple structure throughout an extended period of time.

Abstract: A ceramic heater 1 includes a silicon nitride ceramic substrate 13 and a resistance-heating member 10 embedded in the silicon nitride ceramic substrate 13. The silicon nitride ceramic substrate 13 contains oxygen derived from a sintering aid at an average concentration of 0.4-3.2% by weight in a surface layer portion extending from the surface thereof to a depth of 1 mm. The ceramic heater 1 can be manufactured by firing through hot pressing. A firing jig for use in a firing process has an SiC—C composite layer which is formed therein along the surface of cavities thereof while having a predetermined depth as measured from the cavity surface.

Abstract: A spark plug 100 is configured such that an insulator 2 is formed of alumina ceramic, and the diameter of a through-hole 6 is not greater than 4 mm as measured at a position where conductive seal materials 16 and 17 are disposed. The coefficient of linear expansion of the conductive seal materials 16 and 17 is adjusted to not greater than 6.5×10−6/° C.

Abstract: A resin substrate is made of resin or a composite material containing resin. Pins each having the surface, on which Au plating is formed, are, with a soldering material made of Sn and Sb, soldered to a substrate body having a first main surface and formed into substantially a rectangular shape to project over the first main surface 2A of the substrate body. Wettability of the soldering material for securing the pins and the substrate body to one another is relatively low as compared with that of a Pb—Sn soldering material. Therefore, the height of upward movement of the soldering material along the pin can be reduced. Hence it follows that the pins can sufficiently deeply be inserted into the socket so that the gap between the first main surface of the substrate body and the upper surface of the socket is reduced.

Abstract: An upright-pin-joined resin substrate 11 includes a resin substrate 13 formed from a resin or a similar material and having a main plane 13A and a pin pad 17AP exposed on the main plane; and a number of pins 1 joined to the pin pads 17AP by means of a solder HD. The pins 1 are obtained by shaping a wire material MT which is formed of 194 Alloy and has been heat-treated in advance at 450° C. to 900° C. The pin 1 includes a shaft portion 1A and an enlarged-diameter portion 1B having a round surface projecting in a direction opposite the shaft portion 1A. The enlarged-diameter portion 1B and another portion are joined to the pin pad 17AP through soldering. Also disclosed is a method of producing the upright-pin-joined resin substrate; a pin to be employed in the upright-pin-joined resin substrate; and a method of producing the pin.

Abstract: A sintered alumina ceramic obtained by preparing a raw material powder mixture containing alumina and a Group 3A metal oxide or a Group 3A metal compound which provides a Group 3A metal oxide on heating, and firing said raw material powder mixture. The sintered ceramic contains alumina particles having an average particle diameter of 4.0 &mgr;m or smaller. In the sintered ceramic, the total content of alkali metal elements, alkaline earth metal elements, Si, and Ti as converted to oxides accounts for 0.1 mol or less with respect to 100 mols of alumina, the total peak intensity for the principal peaks for ReAlO3 and Re3Al5O12 (Re: Group 3A metal) amounts to from 1 to 75% of the intensity of the principal peak of alumina as measured by X-ray diffraction, and the relative density is 99.0% or higher with respect to the theoretical density.

Abstract: A Li-ion or Li-ion polymer battery, comprised of a battery assembly having a plurality of generally planar cathode sections, each having a flat, metallic cathode current collector tab extending therefrom. A cathode tab weldment joins the cathode current collector tabs together with a cathode battery lead, and an anode tab weldment joins the anode current collector tabs together with an anode battery lead. A battery package contains the battery assembly with the anode tab weldment and the cathode tab weldment within the package and the anode and cathode battery leads extend through the package. A protective insert within the battery package surrounds the anode and cathode tab weldments and isolates the weldments from the battery package. The insert surrounds the battery leads where the battery leads extend through the package.

Abstract: A gas sensor includes a sensor element and a housing having an accommodation hole in which the sensor element is disposed. The housing has at an axial end thereof a cold crimped portion which cooperates with a shoulder portion of the accommodation hole to fixedly hold therebetween the sensor element. The cold crimped portion has an inward flange section, a hollow cylindrical section and a bent section between the inward flange section and the cylindrical section. The cold crimped portion is shaped so as to vary in thickness suddenly at or adjacent the bent section so that the cold crimped portion is assuredly bent at a predetermined position. A method of producing a gas sensor is also provided.

Abstract: The invention relates to a wiring circuit board including an electronic device disposed in a hole of the wiring circuit board; a resin filling the hole such that the electronic device is embedded in the resin; a wiring layer formed on the resin; and an interface between the resin and the wiring layer. This interface has a roughness in a range of 2-6 &mgr;m in terms of ten-point mean roughness.

Abstract: A method of detecting spark plug fouling in an internal combustion engine is provided. The method comprises calculating an integration value of discharge current flowing between electrodes of a spark plug during a period of a spark discharge and judging if the calculated discharge current integration value is smaller than an integration value criterion. The integration value criterion is set at such a value that can discriminate between normal discharge and interior jumping (i.e., jumping due to short circuit caused by fouling). When the calculated discharge current integration value is smaller than the integration value criterion, it is judged that the spark plug has been fouled. By this, it becomes possible to detect a spark plug fouling before the electrodes of the spark plug are short-circuited and disabled to generate spark discharge, i.e., before the spark plug is fouled to such an extent as to cause a misfire. An ignition system for detecting spark plug fouling is also provided.

Abstract: A gas sensor including a metallic shell (1) and an element (2), which is disposed in a hollow portion formed in the metallic shell (1). An inorganic powder (4) is filled into a gap between the element (2) and the metallic shell (1) to thereby hermetically seal the element (2) and the metallic shell (1) against each other. By using an inorganic powder (4) which does not have an exothermic peak within a temperature range up to 700° C. when subjected to differential thermal analysis, gastightness maintained at the gap portion between the element (2) and the metallic shell (1) is not impaired even in a working environment of 600° C. or higher. Talc powder composed of SiO2 and MgO can be used as the inorganic powder (4). However, a binder, such as water glass, is not added to the inorganic powder (4) in order to prevent the inorganic powder (4) from having an exothermic peak within a temperature range up to 700° C.

Abstract: A conductive ceramic bearing ball made of composite ceramic and having a mixed microstructure of a silicon nitride phase and a titanium nitride phase. The content ratio of the silicon nitride phase to the titanium nitride phase is such that the conductive ceramic bearing ball has an average coefficient of linear expansion within a temperature range of 20° C.-100° C. of from 2×10−6/K to 5×10−6/K.

Abstract: A control system for an internal combustion engine is provided which comprises detecting means for detecting a discharge current flowing between electrodes of a spark plug when a high voltage for ignition is applied to the spark plug, judging means for judging whether or not the spark plug is fouled on the basis of the discharge current, and inhibiting means for inhibiting the progress of spark plug fouling when the spark plug is judged fouled. A method carried out by the control system is also provided.

Abstract: A ceramic member for bonding comprises: a ceramic base which is a sintered ceramic; and a metallic layer formed on the ceramic base by metallization, wherein the metallic layer comprises 70 to 85% by weight of at least one of tungsten and molybdenum and 0.5 to 8.5% by weight of nickel.

Abstract: A high-purity alumina sintered body having an alumina purity of not less than 99.9% by mass and a relative density of not less than 97% and exhibiting a weight loss of not greater than 100×10−4 kg/m2 when immersed in boiling 6N H2SO4 or 6N NaOH aqueous solution for 24 hours as measured according to JIS R1614 (1993). The high-purity alumina sintered body is obtained by firing a green body formed from an alumina powder having an alumina purity of not less than 99.9% by mass and containing, as impurities, Si, an Mg, Fe and alkali metals including Na, K and Li in a total amount of less than 100 ppm.

Abstract: A tip portion of a center electrode 2 of a spark plug includes a tapered portion which is tapered such that the diameter reduces axially frontward. A convex portion 2k is formed at an axially intermediate position of the tapered portion so as to project radially outward with respect to an axis 30. The axially measured distance L2 between the vertex of the convex portion 2k (the convex vertex P) and the tip face ID of an insulator is set to less than 0.5 mm. A heat release acceleration metal portion 2m, which is made of Cu or an alloy that contains a predominant amount of Cu, is present at a position located a distance L3 of 1.5 mm as measured axially rearward from the convex vertex P in order to suppress spark erosion by lowering the temperature of the center electrode 2. The heat release acceleration metal portion 2m is formed such that an electrode base material 2n, which encloses the heat release acceleration metal portion 2m, has a wall thickness W of not less than 0.

Abstract: A ceramic member is constituted with a zirconia-containing ceramic material containing 20% by volume or more of a zirconia series ceramic phase mainly composed of a zirconium oxide.