“Thanks to the ability to bond fine-pitch integrated circuits to polyester layers using traditional SMT processes, space savings can be achieved on control printed circuit boards,” says Steve Fulton, engineering manager at Molex, adding, “Before Molex developed this flexible circuit solution, it was impossible to solder integrated circuits onto PET, as the high temperatures inherent in the process would have damaged the polyester. The alternative, conductive epoxy, can cause short circuits between close contacts, thus limiting component packages and sizes.”
By enabling smaller components with narrower pitches, soldering on polyester substrates achieves higher performance levels and reduces costs. To ensure a strong connection, the solder joints are protected by a UV-cured encapsulant, making them resistant to vibration and mechanical shock. Rectangular LEDs can also be attached to enhance backlighting in user interface applications. The flexible substrate is available in clear, transparent, or white versions with typical thicknesses of 0.13 mm and 0.18 mm.
