Self-assembly for three-dimensional integration of functional electrical components

Current microelectronics manufacturing and packaging rely on pick-and-place methods, which are serial manufacturing processes. Self-assembly (SA) is a parallel manufacturing process that can be three dimensional and as such could improve the manufacture of systems that require diverse integration of sensors, actuators, electronics and power sources. This paper describes SA of millimeter-scale parts in which functional electronic components and electrical interconnects were cast into 5 mm cubes of polymethylmethacrylate. Surface forces induced both gross and fine alignment of the cubes. The cubes were bonded using low-melting-temperature alloy, resulting in a self- assembled three-dimensional circuit. This technique could be expanded for assembly of systems having more than 10⁴ components. The ultimate goal is to combine a large number of diverse active components to allow the manufacture of systems having dense integrated functionality.