How to control the quality of reflow soldering?

The reflow soldering process is a soldering process that remelts the paste-like solder that is pre-assigned to the pads of the printed board to achieve the mechanical and electrical connection between the solder ends or pins of the surface-mounted components and the pads of the printed board .

The technology of reflow soldering is no stranger to the field of electronic manufacturing industry. The components on various boards of our electronic products must be soldered to the circuit board by the reflow soldering process. The advantage of this process is that the temperature is easier to control, oxidation can be avoided during the welding process, and the cost of manufacturing the product is easier to control. There is a set of electric heating circuit inside this kind of equipment. After heating nitrogen to a high enough temperature, it is blown to the circuit board where the component has been pasted, so that the solder on both sides of the component is melted and bonded to the motherboard.

I. How to control the quality of reflow soldering, the production process is mainly optimized from these aspects:

1. It is necessary to set up a scientific reflow temperature curve and to do real-time testing of the temperature curve regularly.

2. Solder in accordance with the soldering direction of the PCB design.

3. Avoid vibration of the conveyor during welding.

4. The welding effect of the first printed board must be checked.

5. Whether the welding is sufficient, whether the surface of the solder joint is smooth, whether the shape of the solder joint is half-moon, the situation of solder balls and residues, the situation of continuous welding and virtual welding. Also check the PCB surface color changes. And adjust the temperature curve according to the inspection results. Welding quality is regularly checked during the entire batch production process.

6. Regularly perform reflow soldering maintenance. Due to the long-term operation of the machine, solid or organic pollutants such as rosin are attached. In order to prevent secondary pollution of the PCB and ensure the smooth implementation of the process, regular maintenance and cleaning are required.

2. What should we do during reflow soldering maintenance and what should we pay attention to?

1. A maintenance system for reflow soldering equipment needs to be formulated. We must do equipment maintenance after using reflow soldering, otherwise it is difficult to maintain the service life of the equipment.

2. Every part should be inspected and maintained on a daily basis, paying special attention to the conveyor belt, so that it can't get stuck or fall off;

3. When overhauling the machine, shut down and cut off the power to prevent electric shock or short circuit;

4. The machine must be stable and not tilted or unstable;

5. Regularly reflow the furnace, mesh belt, and condenser, and develop weekly, monthly, and quarterly maintenance plans to ensure the quality of reflow soldering.

For reflow soldering equipment related maintenance and cleaning, it is recommended that water-based products be safe and environmentally friendly, meet the requirements of current environmental protection regulations such as ROHS, REACH, SONY00259, HF, etc., with high cleaning efficiency and low cost.