Research On The Preparation Of Ink Antenna And Inlay Packaged By ACA

RFID (radio frequency identification) is considered as the most popular attentive and advanced contactless sensor recognition technology and widely used in many areas. But the factor which prevents its wider and larger-scale use is the high price of RFID tags. With manufacturing costs of chip dropping continuously, the development of technology which reduce printing costs and Packaging costs have been widely concerned in industry.In this thesis, the nano-silver particles of appropriate size were prepared and the new conductive ink was synthesized. RFID tags that using the conductive ink has a good conductivity. The work provides a very good idea to develop low-cost ,good performance RFID tags.A silver colloid was prepared by reaction of silver nitrate solution with sodium hypophosphite ( as reducer), sodium hexametaphosphate (as disperser) and polyvinylpyrrolidone ( as protective agent ) at water bath temperature of 50°C and mechanical agitation speed of 450r/min.Then adding PH regulator to the silver colloid until the PH=3 at mechanical agitation speed of 600r/min and the ultrasonic power 500W. After standing for a period of time, the silver colloid was centrifuged and washed with a passivating agent and organic solvent. Then the product was dried in vacuum oven at 60°C. Diameters of the particles are approximate to 30nm.RFID tags that using the conductive ink which contains the nano-silver particles has excellent performance. Whose Printing line is uniform and surface is dense. Most important of all, It's resistance is low relatively.In the packing of RFID tags, we have developed a ACA (anisotropic conductive adhesive) to package and manufacture the low-cost RFID tags. In this thesis, ACA was prepared by mixing Ag particles into thermoset epoxy resin, and RFID flip chips were assembled on the aluminum antenna by ACA under 180 oC, 12 sec, 1.4 MPa. It was found that the ACA has a comparatively high Tg. The fractograph shows that Ag conductive particles were captured by the gold bumps other than the aluminum antenna. The static tensile test and wind test reveals that the contact resistance of ACA joint rises up with the time or period increasing. Further, the outwards bend wind destructs more than the inwards bend wind on the contact conductivity of ACA due to its heavier tearing fatigue effect. The inlays remained 10 cm response distance after HHT test of 85°C, 85 %RH, 168 hrs. In a word, the flexible RFID tag inlay assembled by ACA prepared here has excellent flexibility and high reliability.