液体の表面張力を利用したマイクロ部品のセルフアライメントの原理と特性

Abstract

This paper describes the self-alignment principle and characteristics using liquid surface tension for the assembly of microparts. In the principle, the attractive force caused by liquid surface tension is used and servomechnanisms which are too large to align microparts are not required. The surface of each micropart is divided into two kinds of areas: the wettability of one area is higher than that of the other. Using the microparts, the self-alignment is realized as follows: (1) first, a drop of liquid is put on high wettablity surface area of the first part, (2) next, the second part is put on the first one, (3) and then the second part is moved by the surface tension of the liquid so that the wettability area pattern of the first part overlaps with that of the second one, (4) finally, the alignment is accomplished. In this paper, water is used as the liquid. The effects of the water volume change, the position and angle changes of the second part before the alignment on the alignment accuracy are examined experimentally. The experimental results prove that the average of the final alignment errors becomes less than 10μm even if an initial alignment error is 100μm.