Abstract: A test circuit for testing a switching device. The test circuit includes: a first terminal for receiving a drive signal; second, third and fourth terminals respectively coupled to a ground electrode, a control electrode and a power-supply electrode, of the switching device; and a clamping circuit coupled between the second terminal and the fourth terminal. The clamping circuit is configured to, upon turning on of the switching device responsive to the drive signal, cause a voltage at the third terminal to be a first voltage higher than a threshold of the switching device, and, upon turning off of the switching device responsive to the drive signal, cause the voltage at the third terminal to be a third voltage between the threshold and the first voltage, while clamping a voltage at the fourth terminal to a second voltage lower than a withstand voltage of the switching device.

Abstract: This hot-rolled steel sheet has a predetermined chemical composition, in a microstructure, in terms of area%, residual austenite is less than 3.0%, ferrite is less than 15.0%, and pearlite is less than 5.0%, an E value that indicates periodicity of the microstructure is less than 10.7, and an I value that indicates uniformity of the microstructure is less than 1.020, a standard deviation of a Mn concentration is 0.60 mass% or less, and a tensile strength is 780 MPa or more.

Abstract: This steel sheet has a predetermined chemical composition, at a depth position of ¼ of a sheet thickness from a surface, an area fraction of GAM0.5-1.7 is 50% or more and 100% or less, an area fraction of GAM>1.7 is 0% or more and 20% or less, an area fraction of GAM?0.5 is 0% or more and less than 50%, an area fraction of residual austenite is 0% or more and less than 4%, a total area fraction of the residual austenite, fresh martensite, cementite and pearlite is 0% or more and 10% or less, an average grain size is 15.0 ?m or less, an average dislocation density is 1.0×1014/m2 or more and 4.0×1015/m2 less, a total of pole densities of {211}<011> and {332}<113> in a thickness middle portion is 12.0 or less, and a tensile strength is 980 MPa or more.

Abstract: This hot-rolled steel sheet has a predetermined chemical composition, in a microstructure, in terms of area %, martensite and tempered martensite are more than 92.0% and 100.0% or less in total, residual austenite is less than 3.0%, and ferrite is less than 5.0%, an E value that indicates periodicity of the microstructure is 11.0 or more, the I value that indicates uniformity of the microstructure is less than 1.020, a standard deviation of a Mn concentration is 0.60 mass % or less, and a tensile strength is 980 MPa or more.

Abstract: This hot-rolled steel sheet has a predetermined chemical composition, in a microstructure, in terms of area %, residual austenite is less than 3.0%, ferrite is 15.0% or more and less than 60.0%, and pearlite is less than 5.0%, an E value that indicates periodicity of the microstructure is 10.7 or more, and an I value that indicates uniformity of the microstructure is less than 1.020, a standard deviation of a Mn concentration is 0.60 mass % or less, and a tensile strength is 980 MPa or more.

Abstract: This steel sheet has a predetermined chemical composition, Ex. C that is obtained by Ex. C = (%C) - 12 ( (%Ti*)/48 + (%V)/51 + (%Nb)/93 + (%Mo)/96 + (%W)/184} is 0.020% or less, a microstructure at a ¼ depth position of a sheet thickness from a surface contains 60% or more of ferrite, 0% to 5% of MA and a total of 0% to 5% of pearlite and cementite with a remainder of bainite in terms of area fractions, in the microstructure, the average crystal grain diameter is 10.0 µm or less, the average aspect ratio of crystal grains is 0.30 or more, the standard deviation of a Mn concentration is 0.60 mass% or less, a Ti-based carbide having a Baker-Nutting orientation relationship in the ferrite is precipitated in a semi-coherent state, and a tensile strength is 980 MPa or more.

Abstract: A test circuit for testing a switching device. The test circuit includes: a first terminal for receiving a drive signal; second, third and fourth terminals respectively coupled to a ground electrode, a control electrode and a power-supply electrode, of the switching device; and a clamping circuit coupled between the second terminal and the fourth terminal. The clamping circuit is configured to, upon turning on of the switching device responsive to the drive signal, cause a voltage at the third terminal to be a first voltage higher than a threshold of the switching device, and, upon turning off of the switching device responsive to the drive signal, cause the voltage at the third terminal to be a third voltage between the threshold and the first voltage, while clamping a voltage at the fourth terminal to a second voltage lower than a withstand voltage of the switching device.

Abstract: A hot-rolled steel sheet has a predetermined chemical composition in which a microstructure includes 99% or more of martensite by volume fraction and a remainder in microstructure including residual austenite and ferrite, in a cross section parallel to a rolling direction, an average aspect ratio of prior austenite grains is less than 3.0, a proportion of sulfides having an aspect ratio of more than 3.0 among sulfides having an area of 1.0 ?m2 or more is 1.0% or, less, in a thickness middle portion, and a pole density of {211} <011> orientation is 3.0 or less, and a tensile strength TS is 980 MPa or higher.

Abstract: A hot-rolled steel sheet includes a specific chemical composition, and includes a microstructure represented by, in vol %: retained austenite: 2% to 30%; ferrite: 20% to 85%; bainite: 10% to 60%; pearlite: 5% or less; and martensite: 10% or less. A proportion of grains having an intragranular misorientation of 5° to 14° in all grains is 5% to 50% by area ratio, the grain being defined as an area which is surrounded by a boundary having a misorientation of 15° or more and has a circle-equivalent diameter of 0.3 ?m or more.

Abstract: A method for testing a semiconductor chip that has a pn junction constituting a parasitic diode therein includes: causing probe terminals to be in contact with front surface electrodes of the semiconductor chip; obtaining a temperature of the semiconductor chip by measuring electrical characteristics of the parasitic diode through at least one of the front surface electrodes and a back surface electrode and by referring to prescribed temperature characteristics of the parasitic diode; if the obtained temperature is not within a prescribed tolerance from the predetermined target temperature, heating up the semiconductor chip by applying voltage between one or more of the front surface electrodes and the back surface electrode; and once the obtained temperature increases and reaches the predetermined target temperature within the prescribed tolerance, testing electrical characteristics of the semiconductor chip through the front surface electrodes and the back surface electrode.

Abstract: A hot-rolled steel sheet according to an aspect of the present invention has a predetermined chemical composition, in which, in a location at a depth of ¼ of a sheet thickness from a surface, an area ratio of ferrite is 10% to 55%, a total area ratio of bainite and martensite is 45% to 90%, a total area ratio of the ferrite, the bainite, and the martensite is 90% or more, an average crystal grain size is 12.0 ?m or less, in a texture measured in a sheet thickness central portion, a maximum pole density of orientation groups of {100} <011>, {211} <011>, {311} <011>, {110} <011>, and {332} <113> is 8.0 or less, a total of pole densities of {211} <011> and {332} <113> is 10.0 or less, and a tensile strength is 950 MPa or more.

Abstract: This steel sheet has a predetermined chemical composition and the steel sheet in which, at a ¼ depth position of a sheet thickness from a surface, an average grain size is 15.0 ?m or less, a total grain boundary number density of solute C and solute B is 1.0 solute/nm2 or more and 12.0 solutes/nm2 or less, a total of pole densities of {211}<011> and {332}<113> in a thickness middle portion is 12.0 or less, and a tensile strength is 780 MPa or more is adopted.

Abstract: A method for testing a semiconductor chip that has a pn junction constituting a parasitic diode therein includes: causing probe terminals to be in contact with front surface electrodes of the semiconductor chip; obtaining a temperature of the semiconductor chip by measuring electrical characteristics of the parasitic diode through at least one of the front surface electrodes and a back surface electrode and by referring to prescribed temperature characteristics of the parasitic diode; if the obtained temperature is not within a prescribed tolerance from the predetermined target temperature, heating up the semiconductor chip by applying voltage between one or more of the front surface electrodes and the back surface electrode; and once the obtained temperature increases and reaches the predetermined target temperature within the prescribed tolerance, testing electrical characteristics of the semiconductor chip through the front surface electrodes and the back surface electrode.

Abstract: A hot-rolled steel sheet according to an aspect of the present invention has a predetermined chemical composition, in which, in a location at a depth of ¼ of a sheet thickness from a surface, an area ratio of ferrite is 10% to 55%, a total area ratio of bainite and martensite is 45% to 90%, a total area ratio of the ferrite, the bainite, and the martensite is 90% or more, an average crystal grain size is 12.0 ?m or less, in a texture measured in a sheet thickness central portion, a maximum pole density of orientation groups of {100} <011>, {211} <011>, {311} <011>, {110} <011>, and {332} <113>is 8.0 or less, a total of pole densities of {211} <011>and {332} <113> is 10.0 or less, and a tensile strength is 950 MPa or more.

Abstract: A semiconductor test circuit, apparatus, and method having a first relay disposed between a power supply and a switching element, a second relay disposed between a connection point of the switching element and a reverse conducting-insulated gate bipolar transistor (RC-IGBT) chip and a snubber circuit, a third relay disposed between the switching element and the RC-IGBT chip and a coil, and a fourth relay disposed between a diode and the switching element. A turn on/off test of an IGBT portion is performed by turning on the second and fourth relays. An avalanche test of the IGBT portion is performed by turning on the second relay. A short-circuit test of the IGBT portion is performed by turning on the first relay. A recovery test of an FWD portion is performed by turning on the first and third relays. At this time probes are brought into contact with electrodes once.

Abstract: A hot-rolled steel sheet includes a predetermined chemical composition, and a structure which include, by area ratio, ferrite and bainite in a range of 80% to 98% in total, and martensite in a range of 2% to 10%, in which in the structure, in a case where a boundary having an orientation difference of equal to or greater than 15° is defined as a grain boundary, and an area which is surrounded by the grain boundary, and has an equivalent circle diameter of equal to or greater than 0.3 ?m is defined as a grain, the ratio of the grains having an intragranular orientation difference in a range of 5° to 14° is, by area ratio, in a range of 10% to 60%.

Abstract: A hot-dip galvanized cold-rolled steel sheet has a tensile strength of 750 MPa or higher, a composition consisting, in mass percent, C: more than 0.10% and less than 0.25%, Si: more than 0.50% and less than 2.0%, Mn: more than 1.50% and 3.0% or less, and optionally containing one or more types of Ti, Nb, V, Cr, Mo, B, Ca, Mg, REM, and Bi, P: less than 0.050%, S: 0.010% or less, sol. Al: 0.50% or less, and N: 0.010% or less, and a main phase as a low-temperature transformation product and a second phase as retained austenite. The retained austenite volume fraction is more than 4.0% and less than 25.0% of the whole structure, and has an average grain size of less than 0.80 ?m. A number density of retained austenite grains having a grain size of 1.2 ?m or more is 3.0×10?2/?m2 or less.

Abstract: A hot-rolled steel sheet includes a predetermined chemical composition, and a structure which includes, by area ratio, a ferrite in a range of 5% to 60% and a bainite in a range of 30% to 95%, in which in the structure, in a case where a boundary having an orientation difference of equal to or greater than 15° is defined as a grain boundary, and an area which is surrounded by the grain boundary and has an equivalent circle diameter of equal to or greater than 0.3 ?m is defined as a grain, the ratio of the grains having an intragranular orientation difference in a range of 5° to 14° is, by area ratio, in a range of 20% to 100%.

Abstract: A hot-rolled steel sheet includes a chemical composition represented by, in mass %, C: 0.010% to 0.100%, Si: 0.30% or less, Cr: 0.05% to 1.00%, Nb: 0.003% to 0.050%, Ti: 0.003% to 0.200% and others, wherein a proportion of grains having an intragranular misorientation of 5° to 14° in all grains is 20% or more by area ratio, the grain being defined as an area which is surrounded by a boundary having a misorientation of 15° or more and has a circle-equivalent diameter of 0.3 ?m or more.

Abstract: A semiconductor test equipment can conduct a burn-in test, and has a testing table capable of aligning a plurality of contact units formed of a probe card having a plurality of contact probes each corresponding to each of a plurality of semiconductor chips formed on a semiconductor wafer to contact with the semiconductor wafer, and a holding tool for holding the semiconductor wafer and the probe card in a contacted state; a voltage application circuit having connection wiring lines provided in a manner capable of parallel connection of the plurality of contact units aligned on the testing table, and a plurality of connection units to apply a testing voltage to the semiconductor wafer held on each of the plurality of contact units; and a characteristic measuring circuit for measuring characteristics of the plurality of semiconductor chips formed on the semiconductor wafer according to application of the testing voltage.