Conductors

摘要

Circuit definitions typically include, "a patterned array of electrical conductors." But we rarely stop to think about what a conductor might be made from even though it's the most important part of the circuit. This is because the conductor is assumed to be a non-variable with copper as the de facto standard. Some will want to include Polymer Thick Film circuit conductors, but these are metal-filled polymer composites that should also be counted as metals. The last time we changed conductors was about 100 years ago when easily fabricated copper replaced metal strips of brass. Since the circuit conductor is assumed to be a constant, we spend our time with dielectrics as the main variable in circuit board materials development, although finishes have become important again because of lead-free initiatives. But there is another good conductor and it's not even a metal.