Prototype Stencils step-by-step Tutorial
Step 3 - Place your SMT Components
Place the SMT parts on the PCB using tweezers or a hand vacuum placement tool. If SMT parts are on both sides of the PCB, populate the side with the smallest SMT parts first. After populating and reflowing this side repeat the process on the side with the larger SMT parts. This sequence will keep the largest and heaviest SMT from hanging upside down during reflow, reducing the likely hood that they would fall off the PCB. Molten solder has very high surface energy and can hold most SMT parts even up side down.
Note: Keep the time between printing the solder paste and placing the SMT parts on the solder paste short. The paste manufacturer can guide you on the maximum time between printing and placement.