What's the advantage of vacuum reflow compare to normal reflow?

Compared to normal reflow soldering and vacuum reflow soldering, vacuum reflow soldering has a lower rate of bubbles and voids, which can be controlled to less than 1%. For ultra-high requirement products, it has higher reliability (such as aerospace electronics)

Vacuum reflow soldering, also known as vacuum/controlled atmosphere eutectic furnace, which has a large heat capacity and minimal temperature difference on the PCB surface, has been widely used in Europe and the United States aviation, aerospace, military electronics and other fields.

It uses infrared radiation heating principle, with uniform temperature, ultra-low temperature safety welding, no temperature difference, no overheating, reliable and stable process parameters, no complex process testing, low environmental protection cost operation, etc., to meet the needs of military products multi-species, small batch, high reliability welding.