A press-fit connector for automobile airbag electronic control units (ECUs) was developed and transferred to the mass- production phase by Sumitomo Wiring Systems, Ltd. and AutoNetworks Technologies, Ltd. in 2005. A press-fit connection is a solderless electrical connection technology, which utilizes the mechanical contact force generated between through-holes on a printed circuit board (PCB) and terminals with a width slightly larger than the through-hole diameter.This technology has been widely noted recently as a measure against the "Lead Free Requirement" of materials comprising electric/electronic devices. For the application of this technology to automobile connectors, we have to take into account the more severe environmental conditions required. Consequently, a press-fit connector for automobile airbag ECUs has been successfully developed and mass-produced from 2005. Furthermore, the authors have also developed a new type of hard tin plating on terminals, thus preventing the scraping-off of tin during the insertion process, that could result in a short-circuit on the PCB.