Electrophorectic Self Assembly, A Manufacturing Process for Various Industries

Abstract

Electrophoretic Self Assembly (ESA) is the name for a manufacturing process where large, functional particles (hundreds of microns) are imaged or properly placed using the electrical forces found in the electrophotographic imaging process. The functional particles are the “toners”, in this case liquid toners; and the imaging surface is a fixed configuration printing plate or the traditional optically addressable plate.A typical use for this technology is the high volume manufacture of RFID(radio frequency identification tags). Silicon die of the order 400x400x50 micron in dimension needs to be accurately placed in X & Y; rotated in alignment with the x axis, and oriented (heads vs tails) or correct side up. For commercial success this needs to be done quickly and at cost levels approaching the graphic art industry. I will describe experiments in which silicon die is coated (one side) with a charge control layer, which when dispersed in an Isopar diluent (containing a suitable charge director); will impart are suitable ionic charge to the die. This will allow it to be placed, rotated and oriented on a suitable substrate.The presentation will report progress in this endeavors and include calculations of the expected imaging forces and a limit to the largest die than can be imaged. Other possible commercial applications will be discussed.