Abstract: A prober interface card is provided which improves dielectric absorption characteristics between needles and signal patterns, and conductors with different potentials. A side guard conductor, having a specific height and depth, is disposed so that there is no insulating material between a needle with a connected signal pattern and an adjacent needle with its side guard conductor.

Abstract: A signal switching apparatus performs precise and high speed measurements that indicate DUT breakdown. Several switching circuits having multiple signal switching apparatus provided in parallel with input terminals and output terminals. Each switching circuit is structured to have; (a) A first switch circuit which inputs the guard signal together with the low current measurement signal; (b) a current limiting circuit connected to a stress signal terminal on the input; (c) a second switch circuit connected on the input to the output of the current limiting circuit, having a guard terminal connected to the output of the first switch circuit; (d) A guarded line, one end of which is connected to the output terminals, and the other end of which is connected to the first switch circuit and the output of second switch circuit.

Abstract: Disclosed is a measurement method and apparatus by which measurement of the breakdown voltage of a semiconductor device under test (DUT) may be conducted with an inexpensive measuring system in which thermal stress applied to the DUT is small and thus measurement error caused by characteristic change of the DUT is less. A constant current smaller than the breakdown current of the DUT is applied to a DUT using a constant current source, and waveforms between terminals of said DUT are observed by a waveform observation device, thereby measuring the trigger voltage and the latchback voltage. When a constant current I is applied to the DUT from the constant current source, a stray capacitance C between terminals of said DUT is charged. Thus, the voltage between terminals of said DUT is increased with a constant inclination (I/C) as time goes by.

Abstract: An apparatus for producing a high voltage comprising a high voltage output means operating on a system common voltage, and a floating power supply means operating on the output voltage from the high voltage output means which is at a floating common potential.

Abstract: An ether compound is advantageously produced by an ether exchange reaction of a different ether compound and a hydroxy group containing compound in the presence of a heteropoly acid or an acidic salt thereof as the catalyst. The catalyst is novel and is extremely effective to the present process and brings about less by-products compared to other processes or other catalysts.

Abstract: Oxyalkylene group of an alkylene oxide is inserted into a chain-type ether compound having at least one lower alkyl group by reacting the latter with the alkylene oxide in the presence of a catalyst prepared by mixing boron trifluoride and/or stannic chloride with an active-hydrogen compound exemplified by water or a lower aliphatic alcohol. The reaction results reduced formation of by-product dimer of the alkylene oxide even under an increased charging ratio of the alkylene oxide to the chain-type ether.

Abstract: A process for the production of a mono- or poly-alkylene glycol diether which consists of reacting an ether having at least one lower alkyl group with alkylene oxide in the presence of a heteropoly acid or a heteropoly acid acidic salt. Heteropoly acids and their acidic salts whose ratio of the hetero and coordinate atom is 1:6 and 1:12 are preferably used.