Ultra-thin and super-ultra-thin sheets (less than 0.5 mm thickness) are applied daily, especially in electronic devices, smartphones, laptops, semiconductors, and other high-value applications. In fact, the spot-welding process is a key technology in the automobile industry as known well. However, it has never been considered in welding ultra-thin and super-ultra-thin material sheets. This is related to many troubles, such as reliability, operation stability, and accuracy level. To overcome these troubles and to explode new applications, we developed a novel arc-plasma-spot welding technology that can join super-thin sheets 0.02 mm and thicker for the first time. This technology is a hybrid spot welding process between Tungsten inner gas (TIG) and Plasma arc welding (PAW) that benefits both welding processes while preventing disadvantages. The main discovery points in this technology are a novel narrow nozzle and a beam nozzle. In this paper, a series of fundamental studies were done. The tungsten electrode wear was investigated. The miss-arc phenomena were calculated. The spot bead formation was examined.