摘要:
A method for manufacturing a semiconductor device comprising: a step for readying each of a semiconductor element (1), a substrate (2) having Cu as a principal element at least on a surface, and a ZnAl solder chip (3') having a smaller shape than that of the semiconductor element; a step for disposing the semiconductor element and the substrate so that respective bonding surfaces face each other, and sandwiching the ZnAl eutectic solder chip between the substrate and the semiconductor element; a step for increasing the temperature of the ZnAl solder chip sandwiched between the substrate and the semiconductor element while applying a load (31) to the ZnAl solder chip, causing the ZnAl solder chip to melt, and forming a ZnAl solder layer (3); and a step for reducing the temperature of the ZnAl solder layer while applying a load to the ZnAl solder layer.
摘要:
An ultrasonic flowmeter includes a time measurement unit configured to measure a plurality of propagation times from a time point at which an ultrasonic wave starts to be transmitted to each crossing time point at which a reception signal of the ultrasonic wave crosses a reference level after the reception signal crosses a threshold voltage; and a flow rate measurement unit configured to extract, from among the plurality of propagation times, a specific propagation time whose difference from a reference propagation time is within a first predetermined range, and use the specific propagation time to calculate a flow rate of fluid through which the ultrasonic wave propagates.