Graphite (carbon) finishing coating is a high-strength conductive material. The coating is designed to protect effectively against the harmful environmental influence on the equipment of push-button keyboards (it is applied to landing areas). As it is a contact coating it can be combined with other finishing coatings, for example, with hot tinning HASL or ENIG (immersion gold).
It is durable, affordable, free from oxidation, has high chemical and contact resistance (2−6 Ohms). In addition, carbon has a wide operating temperature range.