Qualification of an enhanced ball grid array package using build-up layers on a metal heat spreader

The innovative package platform discussed in this paper uses build-up technologies to produce circuitry on a copper heat spreader. It applies micro-vias to connect different layers in the substrates. Like any new technology, there are some remaining assembly concerns and challenges with the package design and performance. Additionally, business risks involved in the substrate selection were also discussed. The package under study was certified for product use. The evaluation results showed the package platform under study is capable of achieving accepted reliability performance. However, some assembly issues need to be resolved before volume production, for instance, low wire bonding yield and solder ball mounting defects. It is important to note business risks before the adoption of any new technologies. The team found that the product won't benefit from the most advanced technologies if the substrate/package materials supply is unstable or interrupted. The results and learning from this package certification will be helpful for future advanced product/package development.