Meaning
Soldering processes utilizing an alloy of eighty percent gold and twenty percent tin create high strength hermetic seals at a melting point of two hundred eighty degrees Celsius. This technique provides a lead free solution for attaching components that require high thermal conductivity and fluxless assembly.
Seal Interface
The liquid solder wets the metallized surfaces of the package and the lid to form a continuous metallic bond. Preforms or plated layers provide the necessary alloy volume for the joint. Because the process occurs without chemical flux, the internal atmosphere remains free of organic contaminants.
Reflow Profile
Heating cycles must reach the eutectic temperature quickly to ensure a uniform melt across the entire sealing perimeter. A controlled cooling phase prevents the formation of brittle intermetallic phases that might compromise the joint. Vacuum or inert gas environments during this stage prevent oxidation of the molten metal.
These conditions result in a reliable mechanical connection.
Joint Reliability
The resulting bond withstands subsequent assembly steps that occur at lower temperatures. High creep resistance ensures the seal remains intact during extreme thermal cycling or mechanical shock. Mechanical integrity is verified through leak testing and shear strength analysis.
This process supports long term performance in harsh environments.
