Reliable joining technologies are essential for fabrication of microstructures such as micro-machines, and particularly technologies that are capable of jointing different types of materials. However, these technologies cannot be used for materials that have different rates of thermal expansion or in cases where the adhesives have an effect on the properties of the component materials. Our research focused on developing a direct jointing technology which employs hydrogen bonding. In this technology, OH radicals are absorbed into the surface of the material to be bonded by modifying its surface properties by ion irradiation. We studied the modification of the surface properties of two resins, (SU-8 and PMMA) by H 2 O ion irradiation and Ar cleaning. It was confirmed that the presence of H 2 O ions on the surface of these resins improved their hydrophilic properties and also the peel strengths of Cu membrane s deposited onto both resins. Based on the results of these studies, a series of experiments were conducted in which two different materials, (copper plus one or other of the resins) were joined directly and the results were evaluated. Each of the resins could be joined to copper by heating to a temperature of 100 °C and pressurizing to 10 MPa. This jointing technology will now be applied to the fabrication of the tilt sensors that we are currently developing.

Non-member (TOKAI RIKA CO., LTD.) Hiroshi Ueno Non-member (TOKAI RIKA CO., LTD.) Koichi Itoigawa Member (TOKAI RIKA CO., LTD.) Satoshi Nishida Non-member (NANOCREATE CO., LTD.

Capacitive inclination sensors have the advantage that they can easily provide a linear analog output with respect to inclination. Although inclination sensors featuring this advantages are already commercially available, they are generally too large. We fabricated a micro-capacitive inclination sensor by a combination of a resin forming method and a mold. Electrodes of the sensor are 40 lm in a gap and 12 mm 2 in area. The sensor detects difference of capacitance, which varies with movement of silicone oil accompanying with inclination of the sensor. Since the dimensions of the sensing region are 5 9 5 9 3 mm 3 this inclination sensor is expected to be widely used in fields where efficient and reliable position control is a primary factor to be considered. The use of resins is also expected to contribute to a reduction in the costs of materials. We successfully fabricated a micro inclination sensor as a molded product. In future, we will wire up the device to complete this inclination sensor, and will then conduct performance evaluations. If techniques using resin-molded parts are introduced to the low-cost mass-production of Micro Electro Mechanical Systems devices, the range of applications will further expand to new areas of technology and industry.