Facilitating Process and Material Changes in Production Soldering with Nitrogen Available to Purchase

The use of nitrogen‐based soldering environments, rather than ambient air, has been widely promoted for both reflow and machine soldering. Earlier claims of process improvements derived mainly from the enhancement of process windows related to improved solderability. The improvements seem to be accepted in the industry but may not be very significant except when accompanying other changes in production soldering facilitated by the use of inert environments. Appropriate process changes include the use of finer pitch devices and more densely populated boards and changes in cleaning technology or the use of no‐clean processes. Material changes include the increased use of new technology for both pastes and fluxes (generally no‐clean), increased use of high temperature solder alloys and the possible need to use lead‐free alloys for environmental reasons. This paper discusses the relationship between atmosphere effects on soldering processes, and process and material changes which favour soldering in atmospheres other than air. It presents some recent data on improvements to soldering resulting from the use of nitrogen environments.