Anisotropic conductive film, commonly called ACF Tape is used in a bonding technique called ACF Bonding. ACF Bonding is used for joining FPC to PCB or FPC to LCD Panel. ACF Bonding is used where the pads on the PCB/FPC are extremely fine and the pitch between them is also very fine. The fine pitch would mean that hot bar soldering would not work as the solder would spill over and create a bridge between the pads.
ACF Bonding involves a two-stage process; ACF Laminating and ACF Final Bonding. The lamination process involves applying the ACF tape to one of the components and using a low temperature and low force to only slightly activate the adhesive and keep the tape in position. The final bonding process involves high heat and higher force to activate the adhesive and properly bond the components.
A pulse heat power supply and pulse heat bonding head are ideal for this type of application. The pulse heat power supply controls the heating cycle by using closed loop feedback via a thermocouple on the heater tip.