Solder Paste

Solder paste is a blend of powdered solder and flux used in PCB assembly to secure components temporarily before soldering. It is applied to the PCB through a stencil to ensure it is precisely placed on the solder pads.

Once the solder paste is applied and the components are placed, the assembly is subjected to a reflow oven. In the reflow process, the paste is heated until the solder particles melt, creating a strong bond between the component leads and the PCB pads. The flux within the paste also plays a crucial role, as it helps remove oxidation from the metal surfaces, promoting better solder flow and adhesion.

The composition and quality of the solder paste are essential for achieving reliable solder joints. Factors such as the size of the solder particles, the type of flux, and the paste's viscosity must be carefully controlled to ensure optimal performance. Proper handling and storage of solder paste are also important to maintain its effectiveness and prevent issues like solder balling or poor wetting during the reflow process.