Prototype Stencils step-by-step Tutorial

Step 1 - Setup your prototype stencil
1. Place the large L-shape board holder on a flat surface and tape it down to prevent it from moving.
2. Place the PCB into the board holder.
3. Place the small L-shape board holder next to the PCB and tape it down to preventit from moving.
4. Align the stencil over the PCB SMT land pattern (SMT Pads).
5. Tape the prototype stencil on the large L-shape board holder.

Step 2 - Apply the solder paste using your prototype stencil
1. Place the solder paste on stencil to one side of the hole pattern.
2. Place the squeegee blade on the stencil outside the solder paste. Tilt it 15 to 20 degrees from vertical (toward the solder paste) and drag it and the solder paste across the hole pattern. Hold a light to medium pressure on the squeegee against the stencil. Carefully lift the stencil away (UP) from the PCB.

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 parts from hanging upside down during reflow, reducing the likely hood that they would fall off.

Step 4 - Reflow your PCB
1. Preheat toaster reflow oven for a minimum of five minutes.
2. Set the oven to bake and set the temperature to the highest baking temperature setting (450 to 500 degs F).
3. Before placing the PCB in the oven cut a piece of the Temperature Marker (413 degs F) with a blade or a sharp knife and place it on the surface of the board next to a large component (PLCC or QFP). Insure you can see the Temperature Marker through the oven door.
4. When the Temperature Marker melts remove board from the oven.

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