1. PCB deformation due to temperature gradient
Reflow soldering processing involves exposing the PCB to high temperatures so that the soldering flux between the solder joints and the PCB melts to form strong solder joints. However, due to the large temperature gradient in reflow processing, i.e., the temperature varies greatly in different areas of the PCB, this may cause the PCB to deform. Once the PCB is deformed, it may result in a loose or broken connection between the solder joint and the PCB, which can affect the reliability of the product.
In order to mitigate this effect, manufacturers usually use various methods to improve the thermal stability of the PCB, such as increasing the thickness of the PCB, changing the PCB material, or using multi-layer PCBs.
2. Component damage caused by temperature gradients
Components used in SMT processing are usually very small models of electronic components, these components are very sensitive to temperature changes. Due to the large temperature gradient in reflow soldering processing, if appropriate measures are not taken, it may lead to component damage. For example, if a component is placed in a higher temperature area of the PCB, it may cause the plastic casing of the component to melt, which can damage the internal circuitry of the component.
To mitigate this effect, manufacturers often take measures such as placing components in lower temperature areas or using components that are more resistant to high temperatures.
