Metal provides the ultimate gas and moisture barrier that can convey lifetime values predicted to be more than 100 years.
Although raw metals can be quite inexpensive, the fabrication methods used for packages generally add substantial cost. So
while metal is the gold standard, this is unfortunately reflected in the price. But, metal packaging, because it is typically
electroplated, can release contaminants such as hydrogen; devices that are sensitive to hydrogen may use hydrogen getters
within the metal enclosure. Metal and metal composites are presently used as the electrical conductors for devices, packages
and PCB interconnects, but this could change in the future as nanotechnology and organic conductor advance. A process
called injection molding metal (IMM) might offer some savings to metal packaging, but the electrical conductivity of
enclosures, regardless of how they are made, requires insulation and special processes that add cost.