Thermal curable silver conducting paste used for the preparation of the tag antenna coils of the radio frequency identification

摘要

A thermal curable silver conducting paste used for preparation of the tag antenna coils of the radio frequency identification (RFID) tag was presented. The typical composition of the paste was determined as (wt%): flake silver powder. 59.80, spherical silver powder, 5.20, organic vehicle solution, 35.00. The paste was screen printed on the substrates of papers, and then thermal cured at the peak temperature of 130-150 Celsius degrees for 60-120 seconds. The SKM image indicated that the cured film was perfectly flat and compact. The sheet resistance of the cured film was about 2 milli-ohms per millimeter square at the thickness of 25 micros determined by a four-point probe technique. The pencil hardness (H) of the cured film was more than 2H. In addition. the rheological behavior of the typical paste demonstrated shear thinning property. The thixotropy behavior shown that the silver particles in the paste have flocculated weakly at rest.