Prototype Stencils step-by-step Tutorial

Step 2 - Apply the solder paste using your prototype stencil

Place the solder paste on the stencil to one side of the hole pattern. Spread the solder paste the full width of the hole pattern.

Note: Before using the solder paste remove it from refrigeration and let it warm to room temperature. Before printing with the solder paste stir it for five minutes.

Holding the stencil in contact with the PCB take the squeegee and place it on the stencil outside the solder paste. Tilt it 15 to 20 degs from the 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.

Inspect the solder paste print to ensure all the lands have solder paste on them and the paste is not smeared. If the print is not good use a spatula to remove the solder paste from the PCB and place it on the stencil again. Clean the paste that remains on the PCB with alcohol and a clean rag. Let the PCB dry and print the solder paste again.

NOTE: If the board has SMT components on both sides, print the second side with the PCB on ESD (Electrostatic Discharge) safe cardboard. The cardboard can be cut out to clear the SMT components from the first reflow. All work surfaces should be conductive and grounded.


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