The main function of the PCB surface is to increase the wettability of the conductor pad as to the soldering. Non-chemical surfaces also have some other functions as e.g. to protect the copper below from oxidation and thus to extend the shelf life. We offer a choice of various surfaces as follows: ♦ HAL lead free ♦ chemical tin ♦ chemical gold ♦ chemical silver (on request). You will find more details concerning the different coatings below to help you to find the right surface for your PCB.