Yoshifumi Matsumoto

Fabrication of Coil Lines with High Aspect Ratio for Electromagnetic Actuators

Actuators are finding increasing use in the various fields. And, it is one of most important parts for machines because it determines its performance. Actuators account for a large percentage and volume and weight of a product compared with other parts. Therefore, the progress in downsizing of actuators was required. Then, we have proposed a high aspect ratio coil lines for electromagnetic actuators in order to expect to reduce the size and increase the output power. To realize these coils and actuators, we have fabricated a three dimensional X-ray lithography and metallization process. Using these processes, we have formed three-dimensional coil lines with high aspect ratio that could be used in electromagnetic actuators. In this paper, we have fabricated coil lines with 10 mum line width, 20 mum pitch and aspect ratio of 5 on the surface of an acrylic pipe by mean of three-dimensional X-ray lithography technique. And, a void-free metallic deposit could be formed on a thin coil lines by electroplating method. It is very expected the high performance microcoils and actuators with high aspect ratio could be manufactured in spite of the miniature size.

An Electromagnetic Actuator Using a Cylindrical Coil Created wilth 3D X-ray Lithography and Metallization Techniques

The demand for microactuators is increasing recently. The key technology to realizing practical microactuators is microfabrication process. In the production of microminiature components, the technologies for processing high-aspect-ratio structures are essential. As one of these technologies, the LIGA (German acronym for lithographite, galvanoformung and abformung) process is widely known. Our laboratory researches the LIGA process to three-dimensional microfabrication and established the cylindrical-micro coil production process. In this paper, we have fabricated the cylindrical-microcoil for to the solenoidal electromagnetic type microactuator. We designed and analyzed microactuators, and fabricated and evaluated microactuator coils produced by the combination of three-dimensional X-ray lithography and level copper plating. We succeeded in creating threaded groove-shaped structures (10 mum line width, 20 mum pitch, and aspect ratio of 5) on the surface of an acrylic pipe by means of three-dimensional X-ray lithography. The processing technology enables the formation of thin-wire coil lines whose current paths feature a large allowable current-carrying capacity, enabling the production of miniature, high-output microactuators

Fabrication of a Cylindlrical Microcoil Line with High Aspect Ratio for Electromagnetic Actuators

We designed a scheme to introduce the LIGA process, reduce the coil line width while improving the performance, and thereby drastically cut the production costs. Consequently, we succeeded in fabricating prototype microcoils (line width: 10mum, aspect ratio; approx. 1). However, improvement in the performance of the microcoils requires an increased aspect ratio. We set an objective to fabricate microcoil lines of a high aspect ratio with the dipping method and 3D x-ray lithography in an effort to improve the performance of microcoils. And we succeeded in fabricating microcoil line with a line width of 10mum and an aspect ratio greater than 5

Fabrication of high-aspect-ratio coil for electromagnetic actuators using LIGA process

Actuators are finding increasing use in the various fields. And, it is one of the most important parts of machine in motion because of determine its performance. Recently, the demands for various actuators are smaller size, higher output power, lower input electrical power, and so on. To realize these demands, the key technology is processing of microfabrication. We achieved development of the three-dimensional deep X-ray lithography technique for the spiral micro coil with a high inductance. Therefore, we have fabricated and estimated the solenoidal electromagnetic type microactuator of a low driving power by using this technique. This actuator having the high aspect ratio of coil line is also expected a great force in spite of miniature size. Now, we have obtained the coil line with the width of 10 μm and the aspect ratio of 5. We have also fabricated the measurement system for suction force of electromagnetic actuator. The coil model was measured by this system, and results were relatively in good agreement with simulation results. Using this high aspect coil made by X-ray lithography technique, the electromagnetic actuators have been expected to manufacture with high output force in smaller size.