Method of forming a surface mountable IC and its assembly

摘要

A flip-chip interconnect structure for a RFID tag is described which permits the use of an isotropic electrically conductive adhesive (ECA) without requirement of critical alignment of the chip terminal pads to antenna terminals on the substrate. The interconnect foot print utilizes design principles of standard discrete SMD terminal footprint, which does not require alignment accuracy of a NCA/ACA flip chip bonder. The use of an ECA also eliminates the need for curing the adhesive while under heat and pressure on the chip placement machine. Because of the wide placement tolerance the chips can be placed with a low cost highly productive SMT placement machine. After placement, the assemblies leave the placement machine and are cured in an oven, thereby further improving the productivity of the placement machine. Further productivity improvement is realized by the elimination of bumping which is no longer required. The overall cost reduction of the final assembly by the process of the invention is estimated at about 60 to 85 percent.