Printing radio frequency identification (RFID) tag antennas using inks containing silver dispersions

Rotary letterpress and flexographic printing were investigated for their potential use in making electrically conductive structures. A variety of test patterns were designed to determine some of the printing process capabilities. Antennas for radio frequency identification tags were printed using these techniques. The ink used in this study was a dispersion of silver flakes, and organosilver compounds in an organic vehicle. A variety of printing parameters (inking time, inking speed, printing speed, and printing force) were studied. The printed test patterns and antennas were characterized by a profilometry, electron and optical microscopy, and electrical measurements.