Abstract: Main cells that constitute a semiconductor element having a trench gate structure include first cells, and second cells having a structure in which gate insulating films are more easily broken by energization than those in the first cells, and the number of which is smaller than that of the first cells. At a time of driving the semiconductor element, a common gate drive voltage is applied to gate electrodes of the first cells and the second cells. An electrical characteristic is measured to detect failure of the second cells due to energization at the time of driving. The gate electrodes of the failed second cells are electrically isolated from the gate electrodes of the first cells so that the gate drive voltage is not applied to the failed second cells. The failure of the first cells is predicted based on the failure of the second cells.

Abstract: A state determination device includes an initial waveform storage unit, a waveform acquisition unit, an element temperature acquisition unit, a past waveform storage unit, and a failure state determination unit. The failure state determination unit classifies the time waveform based on the initial time waveform of the gate voltage, the current time waveform of the gate voltage, the element temperature, and the past time waveform of the gate voltage, and determines a fault condition of the IGBT.

Abstract: A thermal-conductive silicone composition containing (A) 0.5 to 2.5 mass % of a crosslinked silicone gel containing (a) an organopolysiloxane having at least two aliphatic unsaturated hydrocarbon groups per molecule, and having a kinematic viscosity at 25° C. of 10,000,000 mm2/s or more, and (b) an organohydrogenpolysiloxane having two or more silicon-bonded hydrogen atoms per molecule; (B) 12.5 to 19.5 mass % of a hydrolysable organopolysiloxane compound; and (C) 80 to 85 mass % of aluminum nitride particles having an average particle size of 0.5 pm or more and 1.5 pm or less. A content of coarse particles in the aluminum nitride particles is 1.0 volume % or less relative to the whole. The coarse particles are 10 pm or more in a particle size distribution by laser diffraction. A thermal-conductive silicone composition has excellent coating workability and favorable pumping-out resistance, and is capable of attaining low thermal resistance by being thinly compressed.

Abstract: The disclosure herein relates to an electric power converter in which a power module accommodating a switching element for electric power conversion is in contact with a cooler, and provides a structure capable of effectively cooling the power module. An electric power converter includes coolers in contact with a power module. A stacked body of the power module and the coolers is accommodated in a case. The surface of the first cooler opposite to the power module is in contact with the case, and an output bus bar is connected to a midpoint terminal and is in contact with the case. The first cooler directly cools the power module by one surface, and absorbs heat from the power module transferred via the midpoint terminal and the output bus bar by another surface.

Abstract: A spark plug includes a terminal electrode extending in an axial direction of the spark plug. The terminal electrode has an end in the axial direction, and has a recess formed in the end of the terminal electrode. The recess has a bottom surface and an identifier on the bottom surface. The recess has a side surface parallel to the axial direction.

Abstract: A spark plug has a central electrode and a ground electrode. The central electrode has an electrode base material part and a noble metal chip of a cylindrical shape and is welded on the electrode base material part. A spark discharge is generated between the noble metal chip of the central electrode and the ground electrode when supplying a predetermined voltage to the spark plug. An intermediate region is formed on an overall surface between the electrode base material part and the noble metal chip. The intermediate region has a primary measurement part and a secondary measurement part. Components of the noble metal chip in the primary measurement area have a first average ratio of not less than 40 wt %, and components of the noble metal chip in the secondary measurement area have a second average ratio of not more than 80 wt %.

Abstract: A failure prediction system disclosed herein is configured to predict a failure of a power converter which converts output power of a power source to power for driving a traction motor. The system may include: a sensor provided at the power converter; and a controller configured to predict a failure of the power converter based on a measurement value of the sensor. The controller may be configured to: calculate a difference between previous and present measurement values of the sensor, wherein the controller repeatedly calculates the difference at predetermined time intervals; obtain intermediate data by applying variable conversion to a plurality of the past differences; calculate a damage level of the power converter based on the intermediate data; and output a warning signal in a case where the damage level exceeds a damage threshold, wherein the warning signal indicates that a timing when the failure occurs is approaching.

Abstract: A power converter includes: a plurality of power modules that houses semiconductor elements for electric power conversion; a pair of holding plates sandwiching a stacked body of the plurality of power modules in the first direction; a pair of connecting beams that connects the pair of holding plates respectively on both side ends of the stacked body in the second direction intersecting the first direction; and a substrate connected to control terminals of the power modules. At least one of the pair of holding plates is provided with a positioner to position the substrate.

Abstract: A spark plug includes a terminal electrode extending in an axial direction of the spark plug. The terminal electrode has an end in the axial direction, and has a recess formed in the end of the terminal electrode. The recess has a bottom surface and an identifier on the bottom surface. The recess has a side surface parallel to the axial direction.

Abstract: A power converter includes: a plurality of power modules that houses semiconductor elements for electric power conversion; a pair of holding plates sandwiching a stacked body of the plurality of power modules in the first direction; a pair of connecting beams that connects the pair of holding plates respectively on both side ends of the stacked body in the second direction intersecting the first direction; and a substrate connected to control terminals of the power modules. At least one of the pair of holding plates is provided with a positioner to position the substrate.

Abstract: The disclosure provides a heat conduction structure with higher heat conductivity. This embodiment is a heat conduction structure where heat is conducted from a first member to a second member. The heat conduction structure includes at least one self-assembled monolayer and a heat dissipation grease. The self-assembled monolayer is formed on at least one surface of the first member and the second member. The heat dissipation grease is disposed between the first member and the second member. The heat dissipation grease is in contact with the self-assembled monolayer.

Abstract: A spark plug has a central electrode and a ground electrode. The central electrode has an electrode base material part and a noble metal chip of a cylindrical shape and is welded on the electrode base material part. A spark discharge is generated between the noble metal chip of the central electrode and the ground electrode when supplying a predetermined voltage to the spark plug. An intermediate region is formed on an overall surface between the electrode base material part and the noble metal chip. The intermediate region has a primary measurement part and a secondary measurement part. Components of the noble metal chip in the primary measurement area have a first average ratio of not less than 40 wt %, and components of the noble metal chip in the secondary measurement area have a second average ratio of not more than 80 wt %.

Abstract: A spark plug has a housing of a cylindrical shape, an insulator of a cylindrical shape, and a packing. The housing has a housing facing surface. The insulator has an insulator facing surface and is supported in the housing. The packing has an insulator side contact surface which is in contact with the insulator facing surface. The packing is arranged between the housing facing surface and the insulator facing surface to face both the housing facing surface and the insulator facing surface. The packing has proximal inner circumferential surfaces formed adjacent with the inner periphery side of the insulator side contact surface. Each of the proximal inner circumferential surfaces has a curved shape smoothly connected to the insulator side contact surface of the packing.

Abstract: A power converter includes: a plurality of power modules that houses semiconductor elements for electric power conversion; a pair of holding plates sandwiching a stacked body of the plurality of power modules in the first direction; a pair of connecting beams that connects the pair of holding plates respectively on both side ends of the stacked body in the second direction intersecting the first direction; and a substrate connected to control terminals of the power modules. At least one of the pair of holding plates is provided with a positioner to position the substrate.

Abstract: A spark plug has a housing of a cylindrical shape, an insulator of a cylindrical shape, and a packing. The housing has a housing facing surface. The insulator has an insulator facing surface and is supported in the housing. The packing has an insulator side contact surface which is in contact with the insulator facing surface. The packing is arranged between the housing facing surface and the insulator facing surface to face both the housing facing surface and the insulator facing surface. The packing has proximal inner circumferential surfaces formed adjacent with the inner periphery side of the insulator side contact surface. Each of the proximal inner circumferential surfaces has a curved shape smoothly connected to the insulator side contact surface of the packing.

Abstract: A failure prediction system disclosed herein is configured to predict a failure of a power converter which converts output power of a power source to power for driving a traction motor. The system may include: a sensor provided at the power converter; and a controller configured to predict a failure of the power converter based on a measurement value of the sensor. The controller may be configured to: calculate a difference between previous and present measurement values of the sensor, wherein the controller repeatedly calculates the difference at predetermined time intervals; obtain intermediate data by applying variable conversion to a plurality of the past differences; calculate a damage level of the power converter based on the intermediate data; and output a warning signal in a case where the damage level exceeds a damage threshold, wherein the warning signal indicates that a timing when the failure occurs is approaching.

Abstract: A semiconductor device may include a stack in which a cooler and a semiconductor module are stacked, the semiconductor module housing a semiconductor element; a contact plate contacting the stack in a stacking direction of the semiconductor module and the cooler; and a spring contacting the contact plate and pressurizing the stack via the contact plate in the stacking direction, wherein the spring may contact a center portion of the contact plate in a direction perpendicular to the stacking direction, and a recess or a cavity may be provided at the center portion of the contact plate, the recess facing the stack.

Abstract: A semiconductor unit may include first coolers arranged in parallel; semiconductor modules, each of the semiconductor modules being interposed between a pair of the first coolers arranged adjacently; a coolant discharge pipe provided at one of the first coolers that is located at an end of a stack of the first coolers and the semiconductor modules, the coolant discharge pipe extending along a stacking direction of the first coolers and the semiconductor modules; a second cooler connected with the coolant discharge pipe; and a reactor interposed between the second cooler and the one of the first coolers located at the end of the stack.

Abstract: There is provided a thermally conductive composite material obtained by dispersing a thermally conductive filler in a matrix. The thermally conductive filler is a mixture including boron nitride particles with an average particle size of 10 ?m to 100 ?m and aluminum nitride particles with an average particle size that is 1/100 to ½ of the average particle size of the boron nitride particles, a content of the boron nitride particles is 60 volume % to 90 volume % with respect to a total amount of the boron nitride particles and the aluminum nitride particles, a content of the thermally conductive filler is 80 volume % to 95 volume % with respect to a total amount of the composite material, and a porosity of the composite material is 10 volume % or less.

Abstract: A semiconductor device includes a semiconductor element, a cooler, and a heat conductive body. The cooler faces one surface of the semiconductor element, and has a flow passage of a coolant. As viewed from the flow direction of the coolant, a width of the flow passage is wider than a width of the semiconductor element. The heat conductive body is made from graphite having such an anisotropy that a heat conductivity in the in-plane direction of a predetermined surface is higher than a heat conductivity in the normal direction of the predetermined surface. The width of the heat conductive body is wider than the width of the semiconductor element as viewed from the flow direction of the coolant. The heat conductive body is configured such that the predetermined surface is non-parallel to both of the flow direction of the coolant and the one surface of the semiconductor element.