Ball grid array substrate with improved traces formed from copper based metal

The present invention relates to ball grid array substrates having traces formed from a copper-based metal. In one aspect, it relates to micro ball grid array integrated circuit packages. A micro-BGA style package for semiconductor device comprises a semiconductor chip and a package substrate. The semiconductor chip includes a plurality of conductive pads. A plurality of transistor circuits are formed upon the semiconductor chip. The package substrate has first and second sides. A plurality of conductive terminals are formed on the first side of the package substrate. At least one of the terminals is electrically coupled to at least one of the conductive pads. A plurality of contacts are formed on the second side of the package substrate. A plurality of traces are disposed on the first side of the package substrate. Each trace provides at least part of an electrical coupling between at least one of the terminals and at least one of the contacts. The traces are formed from a copper based metal having a tensile strength of more than about 60 kg per mm.