Elevated transient temperature leak test for unstable microelectronic packages

A novel method and apparatus for detecting leaks in glass-to-metal seals of microelectronic devices and the like are described which comprise a double-gasketed vacuum station including a base plate having a central hole an a first gasket for exposing one side of the seals to a leak detector; a vacuum fixture surrounding the device provides a marginal region therearound which can be evacuated to prevent helium from permeating the first gasket; the vacuum fixture includes a central opening to expose the other side of the seals to a helium containing atmosphere within a shroud enclosing the device and vacuum fixture; a second gasket provides a seal between the vacuum fixture and device periphery at the central opening in the fixture. For leak tests under controlled time/temperature conditions, an adjacent infrared lamp is used to radiantly heat the package containing the glass-to-metal seals, and a mask is included to avoid direct radiant heating of the gaskets and glass-to-metal seals.