Notes on lead-free reflow temperature

Lead-free reflow soldering is a commonly used reflow soldering process. Compared with lead-tin alloy reflow soldering, it has the advantages of good environmental protection and safer production process. The following are some precautions about lead-free reflow soldering temperature:

1. Suitable soldering temperature range: The melting point of lead-free reflow soldering is usually between 200-220 degrees Celsius, so the control of soldering temperature is very important. It is usually recommended to perform lead-free reflow soldering between 230-250 degrees Celsius. Within this temperature range, the solder can be fully liquefied and the soldering quality can be ensured.

2. Temperature uniformity: When performing lead-free reflow soldering, it is necessary to ensure that the temperature of the soldering area is evenly distributed to avoid poor soldering due to excessively high or low temperatures. The temperature uniformity can be improved by reasonably designing the temperature curve and heating method of the reflow oven.

3. Appropriate holding time: Lead-free solder requires a certain holding time during the reflow process to ensure that the solder is fully liquefied and fully integrated with the soldering point. Too short or too long a holding time may lead to a decrease in soldering quality, so the appropriate holding time needs to be determined based on the specific soldering conditions and solder type.

4. Avoid temperature fluctuations: During the reflow process, avoid sudden temperature changes and fluctuations, especially avoid temperature fluctuations caused by unstable temperature or frequent switching of the reflow oven. Stable welding temperature helps improve welding quality and production efficiency.

5. Temperature monitoring and adjustment: During the lead-free reflow process, the soldering temperature needs to be monitored regularly and the parameters of the reflow oven need to be adjusted in time to ensure temperature stability. Temperature sensors and data logging systems can be used to monitor the soldering temperature and make adjustments based on the monitoring results.

In general, the success of lead-free reflow soldering depends largely on the control and adjustment of the soldering temperature. In actual operation, it is necessary to strictly follow the requirements and process parameters of lead-free solder to ensure soldering quality and product reliability.