| 摘要 |
PROBLEM TO BE SOLVED: To increase communication distance, to improve productivity and to prevent such failures where a print antenna circuit is broken when an IC is connected via an anisotropic conductive film by printing a conductive paste on a substrate to form a circuit pattern and drying this pattern by initial drying for which temperature is specified followed by regular drying. SOLUTION: A circuit pattern is formed by printing a conductive paste on a substrate and then drying for production of a printed antenna circuit that is used for a contactless IC card. In this case, the drying process includes an initial drying at 50 to 200 deg.C and a regular drying at 120 to 180 deg.C. The conductive paste uses a mixture of a 40 to 80 wt.% mixture of the flattened silver powder or flattened silver plated copper powder, 2 to 20 wt.% thermosetting resin such as phenoxy resin and a mixture of 15 to 45 wt.% organic solvent having a desirable 180 to 250 deg.C boiling point of butyl carbitol (R), etc. Then it is preferable to set a viscosity range of the paste at 10,000 to 150,000 centipoises and then at 20,000 to 100,000 centipoises. |
