Part Ⅱ: Common Faults, Causes and Troubleshooting

Flux interruption is a common and tricky problem in the entire electronic solder industry. Solving issues such as flux interruption and uneven flux core size can be both easy and difficult. We will analyze the key aspects to address flux interruption in extruders as follows.

Initial Inspection Points

1. Whether the fluxis filtered before being filled into the fluxtank;

2. Whether the fluxpen is corroded;

3. Whether the temperature of the fluxnozzle meets the standard;

4. Whether the air pressure of the fluxtankis appropriate.

If flux interruption still occurs after resolving the above details, the problem should be traced to the extruder itself, and judged based on the following points:

Extruder-Related Inspection Points

1. Whether the extrusion speed is uniform;

2. Whether the long extrusion ejector rod causes wrapping and dragging of the bar;

3. Whether the die head is designed with air and oil discharge functions;

4. Whether the wire output speed is reasonable.

Bamboo-joint solder wire refers to the solder wire extruded by the extruder with a surface shaped like bamboo joints. This is a common quality defect in solder wire extrusion. The causes of this defect include but are not limited to the following:

1. Various agent molecules in the flux repel each other, forming vacuums inside the flux which further generate bubbles. These bubbles will be retained on the surface of the solder wire during extrusion, resulting in a bamboo-joint appearance.

2. Uneven extrusion speed of the extruder. One of the main reasons for uneven speed is that the extruder is equipped with only one oil cylinder, without subsequent power compensation. This is similar to shifting gears in a manual transmission car, leading to unstable power output. Additionally, the primary and secondary oil cylinders fail to achieve stepless speed regulation, which also contributes to uneven extrusion speed and further causes the bamboo-joint defect.

It is believed that anyone who has used a solder wire extruder has encountered the problem of bubbles on the surface of the extruded solder wire. Is this caused by equipment issues? Admittedly, high-quality equipment can help mitigate such problems, but the root cause does not lie in the equipment itself. The real causes are as follows:

1. Excessive lubricating oil application. The function of lubricating oil is to reduce surface friction, thereby lowering the working pressure of the solder wire extruder. As mentioned earlier, the working pressure has an impact on the service life of the extruder, which will not be elaborated here. Although excessive lubricating oil can reduce friction, it brings side effects: the surplus oil may seep into the rosin, affecting the quality of the solder wire and causing bubbles on the wire surface.

2. Over-high die head temperature combined with excessively slow extrusion speed. The high temperature will cause the surface of the solder wire to bubble during extrusion. Fortunately, if the defect is caused by this factor, users do not need to worry, as it will not affect the final performance and quality of the product.