The preparation and the reliability study of an anisotropic conductive paste (ACP) for RFID tag inlays´ packaging

In this work, an ACP was prepared and applied in the packaging of the RFID tag inlays through flip-chip bonding process. The shear strength, the radio frequency performances (Resonance Frequency and Scattering parameters-S11) before and after the aging tests (high humidity and temperature test, 85 °C, RH 85%) and the Maximum Read Distance of the prepared RFID tag inlays were used to evaluate their reliabilities. And the results were compared with those of RFID tag inlays packaged with a commercial ACP under the same bonding conditions. It was found that the radio frequency performance of the High Frequency RFID tag inlays packaged with the ACP prepared here and the commercial ACP, almost were identical and remained unchanged after the aging test. And the shear strengths of them both increased after the aging test. It was revealed that the ACP prepared here has the same performance of the commercial product. The prepared ACP maybe performed better than the commercial product from the relationships between the maximum read distances of the UtraHigh Frequency RFID tag inlays and the aging hours. It can be concluded that the preapared ACP can be applied in the RFID tag inlays assembling industry. It is another choice for the RFID tag manufactures. And this test system can also be used to evaluate the reliability of the RFID tag inlays.