Reasons for BGA virtual soldering and its control methods

Date：2024-01-19 17:23:31Views：82

BGA (Ball Grid Array) is a common packaging method for electronic components, and its welding quality directly affects the performance and reliability of electronic products. Virtual soldering is a common defect in BGA welding process, which can lead to poor contact between solder joints and pads, thereby affecting the electrical performance and mechanical strength of the product. This article will introduce the causes and control methods of BGA virtual soldering, helping readers better understand and solve related problems.

1、 The reasons for BGA virtual soldering

1. Welding process issue: Improper control of parameters such as temperature, time, and pressure during the welding process can lead to insufficient bonding force between BGA solder balls and substrates, resulting in virtual soldering. In addition, poor quality materials such as flux and solder used during the welding process may also lead to the occurrence of virtual soldering problems. one

2. Excessive gap between solder balls and substrates: Excessive gap can lead to a decrease in the contact area between solder balls and substrates, thereby reducing the bonding force between solder balls and substrates. In addition, excessive gaps may also cause damage to the solder balls due to stress, thereby exacerbating the phenomenon of virtual welding.

3. Substrate surface pollution: Substrate surface pollution (such as oxides, oil stains, etc.) can affect the contact between solder balls and substrates, thereby reducing the bonding force between solder balls and substrates. In addition, surface contamination of the substrate may also prevent heat conduction between the solder balls and the substrate, further exacerbating the phenomenon of virtual soldering.

4. Vibration and stress during product assembly: During the product assembly process, BGA solder balls may be subjected to stress from the substrate and other components, which may reduce the bonding force between the solder balls and the substrate, resulting in virtual soldering. In addition, the vibration of the product during the assembly process may also lead to a decrease in the bonding force between the solder ball and the substrate, resulting in virtual soldering.

2、 Control method for BGA virtual soldering

1. Optimize welding process: By precisely controlling welding parameters (such as temperature, time, pressure, etc.), the bonding force between BGA solder balls and substrates can be improved, thereby reducing the occurrence of virtual welding phenomenon.

2. Control the gap between the solder ball and the substrate: Strictly control the gap between the solder ball and the substrate to ensure the contact area and bonding force between the solder ball and the substrate.

3. Keep the substrate surface clean: Regularly clean the pollutants on the substrate surface to reduce the impact on the bonding force between the solder ball and the substrate.

4. Choose high-quality materials: Choosing high-quality materials such as solder and flux can help improve welding quality.

In short, virtual soldering is a common defect in the BGA welding process, which directly affects the performance and reliability of electronic products. By optimizing welding equipment and process parameters, maintaining the cleanliness of the solder pad surface, setting welding parameters reasonably, and selecting high-quality welding materials, the occurrence of virtual welding can be effectively controlled, and the quality and reliability of BGA welding can be improved.