Puhui Electric specializes in the production of reflow soldering machines, pick-and-place machines, and desoldering stations. Here's an introduction to lead-free reflow soldering technology:
I. Requirements for Lead-Free Reflow Soldering Technology
Due to the specific requirements of lead-free soldering, especially the shortened reflow soldering process window and significant dynamic changes in soldering temperature, the technical requirements for lead-free reflow soldering are as follows:
1 Increase the soldering zone temperature by about 10°C.
2 Lower the heating rate in the preheating zone by 0.7-1.5°C/s.
3 Shorten the dwell time in the soak zone by 20-30 seconds.
4 Increase the soak zone temperature by about 10°C.
5 Reduce the dwell time in the high-temperature zone.
In response to these requirements, the following are the expectations from lead-free reflow soldering equipment: a) More heating zones to accommodate the slow heating requirement of the preheating zone. b) The temperature control in the soak zone should ensure that the circuit board reaches the required pre-heat temperature upon entering the soldering area. c) The temperature control system should have excellent and rapid dynamic temperature response characteristics to address the shortened process window in the soldering area. d) Lead-free reflow soldering generally utilizes functions such as nitrogen protection, hot air circulation, and upper and lower infrared heating. e) The lateral temperature uniformity in lead-free reflow soldering should be less than 1°C.
1 Lead-free reflow soldering exhibits smaller lateral temperature differences compared to lead-containing reflow soldering due to its higher temperature.
2 The cooling unit and flux management system in lead-free reflow soldering are more advanced compared to lead-containing reflow soldering.
3 The rails used in lead-free reflow soldering ovens are subjected to special treatments such as hardening, and weld seams are scanned with X-rays to confirm the absence of cracks and air bubbles. The furnace cavity of the lead-free reflow soldering oven should be made from a single piece of metal processing to withstand higher reflow soldering temperatures without deformation.
2 Turn off the electronic speed control switch of the transportation belt from "RUN" to "STOP".
3 Let the small reflow soldering machine run empty for 10-15 minutes.
4 The transmission system of the lead-free reflow soldering equipment is designed with a better anti-vibration structure to avoid disturbances in solder joints.
5 The sealing requirements for the furnace cavity in lead-free reflow soldering are higher.
6 Higher thermal insulation performance is required for lead-free reflow soldering compared to lead-containing reflow soldering.
7 The exhaust and discharge system in lead-free reflow soldering is more sophisticated compared to lead-containing reflow soldering.
For any inquiries regarding pick-and-place machines, please contact Taian Puhui Electric Technology Co., Ltd. We are committed to providing you with the best service.