1. Solder Joint Cracks

1. Excessively fast heating and cooling rate leads to thermal stress between PCB and components.

2. Excessive solder volume causes stress concentration on bulky joints.

3. Poor heat resistance of PCB and components results in delamination and crack extension.

4. Strong extrusion, bending and mechanical shock during post-production handling.

5. Improper solder alloy composition leads to insufficient toughness.

1. Slow down heating and cooling speed to reduce thermal shock and internal stress.

2. Optimize stencil design to control solder volume reasonably.

3. Adopt PCB and components with good heat resistance and stability.

4. Standardize operation procedures to avoid bending and impact on boards.

5. Select proper solder paste to improve crack resistance of solder joints.

2. Open Joints

1. Hidden cold joints and poor soldering wetting in early stage.

2. Long-term alternating temperature and continuous vibration during operation.

3. Defective pad plating and PCB delamination reduce adhesion.

4. Excessive flux residue causes gradual corrosion.

5. Excessive humidity in storage or working environment leads to oxidation.

1. Strictly control the whole process to eliminate hidden cold joints.

2. Optimize solder structure for products working under vibration and temperature change.

3. Inspect PCB strictly to reject boards with poor plating and delamination.

4. Add cleaning process for high-reliability products to remove flux residue.

5. Control humidity in storage and working environment for anti-corrosion.