Method of forming an hermetic seal on electronic and optoelectronic packages

A method comprising

• forming an assembly,
• wherein the assembly comprises a first substrate in contact with a second substrate,
• wherein the first substrate comprises a first wall forming a close-loop boundary defining a volume between the first and second substrates,
• wherein the first wall comprises portions having different heights configured so that the first substrate contacting the second substrate with at least an opening,
• wherein the second substrate comprises a boundary line or a second wall,
• wherein the boundary line or the second wall is configured to contact the first wall;
• placing the assembly in a chamber;
• conditioning an ambient in the chamber,
• wherein conditioning the ambient comprises at least one of
• evacuating gases in the chamber, or
• flowing an inactive gas or an inert gas to the chamber, or
• flowing an inactive gas or an inert gas to the chamber having an exhaust, or
• evacuating gases in the chamber, followed by flowing an inactive gas or an inert gas to the chamber, or
• performing multiple cycles of evacuating gases in the chamber and flowing an inactive gas or an inert gas to the chamber;
• supplying a heat source to heat the wall to form a hermetic seal for the volume,
• wherein supplying the heat source to heat the wall comprises at least one of
• flowing a hot inactive gas or a hot inert gas to the chamber, or
• heating ambient in the chamber, or
• supplying an IR heating directed toward the assembly, or
• heating the chamber, or
• heating a support on which the assembly is located.