Jet stack brazing in a diffusion furnace

A method for batch brazing in a diffusion furnace, comprising:

• inserting a plurality of fusible parts into a plurality of slots of at least one quartz boat;
• transporting the at least one quartz boat, including the fusible parts, into an interior of a reaction chamber of the diffusion furnace;
• disposing an insulation band near a load zone of the diffusion furnace;
• sealing the interior of the reaction chamber;
• adjusting an atmosphere of the interior of the reaction chamber according to a recipe;
• moving a preheated furnace heating element from a location spaced apart from the reaction chamber to a location in substantial proximity with the reaction chamber to increase a temperature of the atmosphere of the interior of the reaction chamber above a predefined brazing temperature for a predefined brazing time period according to the recipe;
• and
• determining that the insulation band is improperly positioned based on a temperature measurement obtained by at least one temperature sensor located near the load zone.