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50 SMT Magazine • February 2016 by Dr. S. Manian ramkumar rocHESTEr iNSTiTuTE oF TEcHNologY The use of anisotropic conductive adhesive (ACA) is not new within the electronics indus- try; however, drop-in replacements don't exist for lead-based and lead-free solder assemblies. Current ACAs require pressure and sequential assembly of components. Sunray Scientific's Novel ACA (ZTACH) is an excellent drop-in ACA replacement that will revolutionize the packag- ing industry and make electronic products more sustainable and green. ZTACH has been proven to enable the use of existing SMT equipment, lower the processing temperatures (75–150°C), and also eliminate the need to apply pressure, thereby eliminating the need to invest in new equipment and processes and reducing energy consumption. ZTACH is composed of conductive, ferro- magnetic particles in an epoxy matrix, which is printed or dispensed on the individual pads or the entire footprint of the components. The ma- terial is cured in a reflow oven, after all compo- nents are in place, in the presence of a magnetic field. The magnetic field aligns the conductive particles in the Z-axis direction, during curing, thereby eliminating the need for pressure. The formation of conductive columns within the ad- hesive matrix during cure provides a very high insulation resistance between adjacent conduc- tors and also eliminates the need for precise printing or dispensing of adhesives onto indi- vidual fine pitch pads (Figure 1). Modification magnetically aligned Novel aca revolutionizes 3d chip stacking Figure 1: The formation of conductive columns within the adhesive matrix during cure eliminates the need for precise printing or dispensing of adhesives onto individual fine pitch pads. Feature sHort