Method for hermetically sealing an electronic circuit package

Abstract From the Canadian patent

A hermetically sealed electronic circuit package is formed by placing a preformed, uncured sealant between a circuitized ceramic substrate and a ceramic cover. The resultant assembly is placed in an evacuated oven which is preheated to a temperature at least as great as the curing temperature of the sealant. Before the sealant reaches its melting temperature, the oven is backfilled with nitrogen and stabilized at atmospheric pressure. The assembly is maintained in the heated environment for a sufficient period of time to substantially cure the sealant. The resulting assembly may be opened to affect any repairs that may become necessary and then reassembled.