According to the heat transfer efficiency of the product and the continuous improvement of welding reliability, reflow soldering can be divided into five stages of development.
First generation: Hot plate conduction reflow equipment: Heat transfer efficiency is slowest, 5-30 w/m2k (different material heating efficiency is not the same), there is a shadow effect.
Second generation: Infrared thermal radiation reflow equipment: Heat transfer efficiency is slow, 5-30w/m2k (different materials of infrared radiation efficiency is not the same), there is a shadow effect, the color of components on the heat absorption has a big impact.
Third generation: hot-air reflow soldering equipment: high heat transfer efficiency, 10-50 w/m2k, no shadow effect, color has no effect on the heat absorption.
Fourth generation: gas-phase reflow soldering system: High heat transfer efficiency, 200-300 w/m2k, no shadow effect, the welding process needs to move up and down, the cooling effect is poor.
Fifth generation: Vacuum steam condensation welding (vacuum vapor phase welding) system: Airtight space without empty welding, the highest heat transfer efficiency, the W-500W/M2K, the welding process to maintain static without vibration, excellent cooling effect, the color does not affect the absorption of heat.