No abstract

We have developed a soft actuator using an ionic polymer-metal composite (IPMC) composed of gold electrodes deposited using vacuum evaporation. In comparison with the conventional plating deposition, the vacuum evaporation both is a simple fabrication process and is environmentally friendly. We observe how the gold electrodes adhere to the ionic polymer using a cross-sectional scanning electron microscope and confirm the working as a soft actuator by applying voltage. Although the displacement characteristic is not comparable to that of the conventional IPMC, this work is worthwhile because many researchers become able to easily enter into the research field of soft actuators.Index Terms-Gold electrode, ionic polymer-metal composite (IPMC), soft actuator, vacuum evaporation.

We propose and demonstrate the concept of using a tuneable liquid crystal micro-lens (LCML) array to improve the image contrast of a pixelated thin film photo-transistor (TFPT) flat panel imager. Such a device can be used to image contents on paper-based media and display a magnified version on a flat panel display for elderly or visually impaired people. Practical aspects including device physical geometry, object scattering profile, LC material, and focusing effect of LCML on an object are considered during the design process with the support of ZEMAX simulations. An optimised effective focal length (EFL) has been calculated for the designed LCML to best relay the objects or contents on a paper to the TFPT pixel plane. The designed LCML devices are fabricated with the optimised EFL, and they have good phase depth profiles which are close to a spherical lens profile. Preliminary test results show that the combination of a TFPT imager with an LCML array can make the image contrast more than two times better than that using the TFPT imager alone. The tuneable EFL of the developed LCMLs are useful in the situation where the LCML is not in direct contact with the imaged object.

In the field of advanced electric devices using fine wafer process below the technology node of 130nm or 90nm, low dielectric constant inter-metal-dielectric (Low-k IMD) have been applied to have high speed operation. And from the environmental viewpoint on electric devices, elimination of the harmful materials like lead (Pb) material is one of the important activities. In such circumstances, we have developed Pb-free Flip-chip Ball Grid Array (FC-BGA) package for Low-k devices using organic substrate. From our experiments on 1296pin FC-BGA package with 12.4 x 12.4 mm size chip, it is concluded that applying solder bump composed of Sn-1.0Ag-0.5Cu and the low stress underfill with Tg 110 o C will realize the Pb-free FC-BGA on Low-k device.

We developed the flip-chip bonding technology on ChipOn-Chip (COC) package with ultra-fine pitch bump, which leads advanced high performance devices. On this package, the realization of the metallographic behavior in the microbump interconnection is the substantial issue for achieving good bondability and reliability. In this paper, to implement Flip-Chip BGA package with COC structure (COC-FCBGA), the metal systems of micro-bump and the dimension especially metal plating thickness have been optimized by precise analysis. And it is confirmed that the specification we fixed on this package would meet sufficient quality level for fine pitch bonding. This COC-FCBGA technology will meet demands for high-end system solutions in very near future.