Solder paste is used in the manufacture of printed circuit boards to connect surface mount components to pads on the board. It is commonly used to create electrical connections and mechanical bonds between printed circuit board pads and surface mount devices, such as resistors and capacitors. It is made up of powdered solder in a flux paste. If you are working on PCB assembly projects, solder paste is essential to complete the task.
A solder paste stencil is used to guide the paste into the areas where it is needed. The solder paste stencil solves any possible problems. After being applied to the printed circuit board, the paste is passed into the pick and place machine. This adds the components which are held in place by it.
Even though the components are stuck, it is best not to move the board too aggressively as the pieces can still fall off. If not soldered, the paste will start deteriorating after a few hours.