MEMS/microelectronics self-assembly based on analogy of Langmuir–Blodgett approach

A self-assembly method is introduced for the assembly of micro-parts onto Si substrates based on analogy of the Langmuir−Blodgett technique. To perform the assembly, Si substrates are prepared with solder-coated binding sites. The micro-parts are suspended in the butyl acetate-water mixture, and after gentle agitation, the micro-parts form a uniform and well-ordered 2-D aggregate at the butyl acetate-water interface. The micro-parts are attached onto the substrate by passing the substrate vertically through the aggregate of micro-parts. Due to the mechanism of the Langmuir−Blodgett technique, the micro-parts are attached onto the substrate. The butyl acetate-water mixture is then heated to 100 °C, molten solder and air bubbles in the boiling water make it possible for the micro-parts to self-align on the substrate. This methodology could give a self-assembly yield of up to 90%, providing a practicable method for micro-assembly.