A new packaging technique has been realized and applied to the imaging module for medical endoscope. In order to realize minimal invasiveness for in-vivo medical device applications, the WL-CSP (Wafer Level-Chip Size Package) is one of the most attractive technology. However, in the field of medical device packaging, the packaging needs are diversified and required number of each package does not meet the huge sized wafer processing. In this new technique, the CMOS image sensor wafer is diced at first, and then individual image sensor chips are rearranged on another smaller handling wafer. As a result, suitable size of the handling wafer can be selected for the production volume, and lower production cost and shorter production lead time can be achieved. The packaged image sensor with new packaging technique showed no significant degration of charactristic of image sensor.

By forming multiple microholes and 64 microelectrodes at the center of a transparent SiN (silicon nitride) diaphragm, we developed a microdevice for chemical stimulation and multichannel measurement of extracellular potentials of cells and tissues. A rat hippocampal slice which was placed on the device was electrically stimulated using one of the 64 microelectrodes, and evoked potentials were measured at multiple areas of the slice. We chemically stimulated the slice by tetrodotoxin molecules released from the microholes, and succeeded in detecting disappearance of the potentials which was caused by inhibition of neural firing.

A digital calibration technique for a column-parallel two-stage single-ended cyclic ADC needs to accurately determine error coefficients that define the quantity of errors caused in the ADC. However, the error coefficients have so far been determined on the basis of estimation from the design parameters of the ADC. Therefore, we proposed a new ADC operation and signal processing scheme to determine them accurately and dynamically by measuring the ADC output code including the errors and verified its effectiveness for precise and high-speed technique of digital calibration by performing a preliminary experiment using the ADC test circuit.