SMT reflow soldering process is a soldering process in which SMT components are attached to a PCB and heat treated in a reflow oven. Here are the specific process steps:
Prepare the PCB: Prepare the PCB board to be soldered and make sure that its surface is flat and clean.
Apply solder paste: Using an automatic or hand tool, apply an appropriate amount of solder paste to the PCB. Solder paste should be applied evenly and precisely to ensure that every solder joint is covered.
Component placement: Attach the SMD components to the solder paste covered positions using a placement machine or by hand. Make sure the components are oriented correctly and aligned with the PCB.
Thermal pretreatment: The PCB with components is sent to the preheating furnace for preheating treatment. The purpose of preheating is to allow the solder paste to melt gradually to ensure the quality of the weld.
Enter the reflow oven: The preheated PCB is fed into the reflow oven. The reflow oven is equipped with a hot zone and a cooling zone at a certain temperature, and the PCB is gradually passed through these two zones through a conveyor belt.
Reflow soldering: In the hot zone, the solder paste is completely melted and made to form a reliable solder connection at the solder joint by controlling the temperature and time. The temperature and time of the solder joint should be reasonably adjusted according to the requirements of the solder paste and components.
Cooling: In the cooling zone, the weld joints will quickly cool and solidify, solidifying the welded connection. The control of the cooling process avoids displacement of the weld joints or incomplete curing.
Through the above steps, the SMT reflow process can achieve a reliable connection between the SMT component and the PCB. Throughout the process, temperature and time need to be tightly controlled to ensure welding quality and reliability. In addition, the selection of high-quality solder paste and components is key to ensure the stability and long life of the welded connection.
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