Check valve package for pb-free, single piece electronic modules, the package having an exterior and an interior, and at least one electronic device mounted within the interior of the package electrically connected to a lead-free solder ball grid array on a surface of the package, the package having a check valve between the interior and exterior of the package configured to allow flow from the interior to the exterior and to prevent flow form the exterior to the interior. The package withstands the solder reflow temperatures for the reflow of the pb-free solder balls of a ball grid array packaging of an NVSRAM during mounting on a circuit board. The package is suitable for packaging circuits containing rechargeable batteries and for packaging other electronic devices.