UV-Thermal Dual-Curing Anisotropic Conductive Paste for Low-Temperature RFID Tag Packaging

Anisotropic conductive paste (ACP) has been widely adopted in flip-chip packaging due to its simple processing and compatibility with fine-pitch interconnects. However, conventional thermally-cured ACP requires high curing temperatures, significantly limiting its applications. This work proposes a novel UV-thermal dual-curable ACP for rapid RFID tag packaging at reduced temperatures. Curing kinetic analysis reveals exceptional reactivity, achieving 78% epoxy conversion within 10 seconds (FTIR at 913 cm⁻¹). The dual-cured ACP exhibits superior thermal stability (Td5% ≥328 °C) compared to thermal-only curing. Additionally, the as-prepared ACP demonstrates good storage stability at 4 °C. When applied to RFID chip packaging, the RFID tags demonstrate excellent operational performance, with transmission distances exceeding 4 meters in the ultra-high frequency (UHF) band and a minimum activation energy as low as 0.2 dBm at 890 MHz, indicating high sensitivity to electromagnetic energy for long-distance reading. This work provides a new efficient, economical, and reliable solution for low-temperature and rapid packaging of RFID tags, with promising prospects for applying this material and technology to heat-sensitive substrates and devices.