一.Temperature control requirements:
Preheating zone: The temperature rises from room temperature to 130~190℃ (or 150℃), the temperature rise slope is 2~4℃/sec, and the time is controlled at 60~150 seconds.
Constant temperature zone (insulation zone): The temperature rises from the highest temperature in the preheating zone to 200℃, the temperature rise slope is less than 1℃/sec, and the time is controlled at 60~120 seconds.
Reflow zone: The temperature reaches the peak temperature (240~260℃, 235~245℃ for lead-free process), the temperature rise slope is about 2℃/sec, and the time is controlled at 30~40 seconds (or 60~90 seconds).
Cooling zone: The temperature drops from the peak to below 180℃, and the temperature drop slope does not exceed 4℃/sec.
二.Time management requirements:
Preheating time: Generally 60~150 seconds to ensure that the solder paste starts to flow and the flux evaporates.
Constant temperature time: generally 60~120 seconds, so that the solder paste is completely dissolved, the oxide is removed, and a uniform solder joint is formed.
Welding time: generally 10~20 seconds, to ensure that the solder joint is completely and evenly formed, to avoid damage to components or poor soldering.
Cooling time: generally 90~150 seconds, to prevent thermal stress and protect electronic components.
三.Other precautions:
1.Before batch reflow soldering operations, the temperature should be tested several times to determine that there is no problem with the appropriate temperature setting and to ensure product quality.
2.Production line technicians need to record the furnace temperature setting and connection speed, regularly measure the furnace temperature curve, and monitor the normal operation of reflow soldering.
3.Measure the reflow soldering furnace temperature once per shift, and test it after each temperature parameter change.
