Sequential shape-and-solder-directed self-assembly of functional microsystems.
We demonstrate the fabrication of packaged microsystems that contain active semiconductor devices and passive components by using a directed self-assembly technique. The directed self-assembly is accomplished by combining geometrical shape recognition with site-specific binding involving liquid solder. Microfabricated components with matching complementary shapes, circuits, and liquid solder-coated areas were suspended in ethylene glycol and agitated by using a turbulent liquid flow to initiate the self-assembly. Microsystems were obtained by sequentially adding components of different types. Six hundred AlGaInP/GaAs light-emitting diode segments with a chip size of 200 microm were assembled onto device carriers with a yield of 100% in 2 min. Packaged light-emitting diodes formed with yields exceeding 97% as a result of two self-assembly steps in 4 min. This self-assembly procedure, based on geometrical shape recognition and subsequent binding to form mechanical and electrical connections, provides a high distinguishing power between different components and a route to nonrobotic parallel assembly of electrically functional hybrid microsystems in three dimensions.
Departments of Electrical and Computer Engineering and Chemistry, University of Minnesota, 200 Union Street SE, Minneapolis, MN 55455, USA.
Wei
W
Zheng
Philippe
P
Buhlmann
Heiko O
HO
Jacobs
D003201:Computers; D008420:Manufactured Materials; D008855:Microscopy, Electron, Scanning; D012666:Semiconductors