This paper presents a new sensing system for carbonaceous nanoparticle measurement using a laser-induced incandescence (LII) technique. Our research group has improved the laser-induced breakdown spectroscopy (LIBS) system used for quantitative analysis. Although the basic principles of LIBS quantitative measurements are well understood, several uncertainties remain concerning complete descriptions—especially for particle size measurement. The elemental composition and density of the particles are determined using LIBS, and particle size measurements are accomplished with the help of LII. In the case of the present system, with temporally resolved LII, measurement of soot primary particle sizes is feasible in a combustion process derived from the ratio of emission signals after a laser pulse because the cooling behaviour is characteristic of the particle size. The LII temporal analysis was performed by a streak camera, which was also used for LIBS analysis. The LII technique allows in situ measurement of the average primary particle size of nanoscale soot particles.

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This paper describes a stochastic counting MEMS sensor, which will be used in low S/N environments like in high temperature plants. A mass which vibrates between two counter electrodes by white voltage noise is “pulled-in” to either of the electrodes by the application of pulse voltage to the mass. The direction of the pull-in is determined stochastically, and the probability that the mass is pulled-in to a particular side depends on mechanical strain applied to the sensor structure. This sensing principle was confirmed by simulation, and then the sensor was prototyped using an SOI wafer. The probability of pull-in to a particular side was tuned by bias voltage applied to the counter electrodes, as predicted by the simulation. When the frequency of the pulse voltage for pull-in increases, the behavior of the sensor becomes unintended, because the mass is pulled-in during dumping vibration after releasing from the previous pull-in. This limits the sensing speed, but strain sensing is possible just counting the number of pull-in to a particular side, which is easy even in low S/N environments.

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We developed an anisotropic wet etching simulator that can predict the etching profile of initial shape, which is two-dimensional and formed by straight lines. New etching rate database of quartz at a special condition was obtained. Improved hull method was used to deal with round corner etching. New programming flow was adopted to avoid improper profile prediction. A friendly graphical user interface was built for user's convenience. The simulation result of this simulator meets well with the experimental results and shows nice accuracy in new emerging faces predicting.

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This paper describes metal-metal electrical connection simultaneously established with anodic bonding between a LTCC (low temperature cofired ceramic) substrate and a Si substrate. Metal pads are composed of Sn on Cu. Sn melts during anodic bonding, absorbing the height margin of the metal pads to ensure good contact between the LTCC substrate and the Si substrate. This study first investigated formic acid vapor treatment before anodic bonding to remove an oxide layer on the Sn surface. The removal of the oxide layer proceeds at a process temperature of 150°C or higher. By the treatment at 250°C, the surface of the Sn layer is smoothed due to reflow effect, but the multilayer structure of the metal pads does not significantly change after 5 min treatment. The bonded metal pad is almost uniform in both structure and composition throughout its thickness. The composition of the bonded metal pads is approximately Sn : Cu = 1 : 1 in atomic ratio, and might have a remelting temperature of ca. 415°C, which is much higher than a reflow temperature in device mounting process.

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Single crystal silicon microcantilevers with different supporting properties are fabricated for nonlinearity analysis. Using a modeling method, the frequency responses of the microcantilevers are fitted and their nonlinearity parameters are calculated. It is found that the nonlinearity parameter decreases by increasing the length of the cantilever. For the cantilever with same length, narrow cantilevers have smaller nonlinearity parameters. Microcantilevers with a “soft” supporting plate are more susceptible to nonlinear behavior, and the nonlinear parameter increases by increasing the length of the “soft” supporting plate.

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