The primary side of a PCBA, usually containing the most complex or major components. The top side of a PCBA having some or all through-hole components (Assembly Types II and III) is the side with the through-hole component bodies, and is also referred to as the ‘component side’. The top side of a PCBA having all SMT components (Assembly Type I) is the final side to receive component mounting materials and components. See Types I/II/II assemblies.
