Check datasheet in case it has some info. I would guess it should work as there is no gas in chip and package. In case if radiations, it is another story.
Apart from the datasheet - as @S.Ma mentioned - try searching to see if there are any specs for the packaging?
A complex system that works is invariably found to have evolved from a simple system that worked. A complex system designed from scratch never works and cannot be patched up to make it work.
Not directly related, may explore parylene coating for few micron to make coating. Normally used for medical grade electronics. Simple and common process in chamber.
