Fabrication of polymer electronic boards by ultrasonic embossing and welding

A method has been developed allowing fabrication of electronic boards from flexible polymer film by ultrasonic embossing and welding within seconds. A commercially available ultrasonic welding machine and micro patterned tools from aluminum are employed first to generate conductor paths on a flexible polymer film, in a further step, surface mounted devices are assembled and fixed on the flexible polymer film by a lid, and meanwhile electrical connected via a z axis conductive tape, both the molding of the lid and the bonding between the lid and electronic boards are implemented on an ultrasonic welding machine. Finally, the effectiveness of electrical interconnection is investigated at elevated temperature, humidity and bending load, exemplified by three simple circuit boards assembled with light-emitting diodes and resistors and capacitor separately, and the experimental results show that the electrical interconnection is effective, stable, and durable.\ud