Sealing method for buried blind hole processing metal package

Buried blind hole machining The flat cover or stepped cover can be welded to the outer casing by manually using a heating table or placed in the furnace. Although the workbench cover is slightly faster, the metal casing at this time is like a heat sink. At the same time as the cover, it absorbs heat from the seal area and heats the inside of the package unless the glass beads for the insulated leads extend completely to the package. Outside the perimeter, but this is an obviously unrealistic requirement.

In addition, buried via processing may cause leakage through the solder due to the pressure difference inside and outside the package, or form a "pore" unless the ambient pressure outside the package and the pressure inside the package due to heat rise at the same rate. Installation of components using epoxy is dangerous due to the temperature rise inside the package unless the glass beads extend completely beyond the perimeter of the casing as described above.

The buried blind hole processing can complete the solder sealing with a belt furnace under a nitrogen atmosphere. Nitrogen is used to prevent oxidation of the solder and also provides a good environment for the sealed circuit. A certain degree of clamping must be used to seal the inside of the furnace to apply pressure to the cover.