Sealing Lid is the packaging module applied to communication equipment, microwave equipment, integrated circuit device, industrial laser, etc. It is generally made of expanded series materials, namely, Kovar alloy. The commonly used material numbers are 4J42, 4J29, 4J36, and the commonly used thickness is 0.25mm, 0.4mm, 0.15mm, etc. It is mainly processed by etching process.