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Electroformed Nickel Step Stencils

Available in Stencil Technologies

Advantages


Step Stencils offer the SMT process engineer significant flexibility in achieving the proper solder paste height and solder paste volume for the overall paste printing process.

Note: Steps are available on the PCB side, the squeegee side, or on both sides of the stencil.

Step-Down Stencils

  • 20 mil pitch QFN: 7 mil thick for R's and C's with a step-down to 5 mil for 20 mil pitch QFNs
  • 16 mil pitch QFN, 0201s and/or µBGA's: 5 mil thick stencil with a step down to 4 mil for the 16 mil pitch QFN, 0201s, and or µBGAs.

Step-Up Stencils

  • CBGA or CGBGA: 6 mil for normal components and a step-up to 8 mil for CBGAs. Extra paste height required for this component due to possible coplanarity issues.
  • Through-Hole Connector: 6 mil for normal components and step-up to 10 mil for the through-hole connector.

Relief Step-Board Side


Bar Code Relief: When the bar code is too close to PCB pads it can cause a gap between the stencil apertures and the pads. The relief pocket allows the stencil to cleanly gasket to the PCB.

 

Raised Via Pads: Raised via pads can prevent the stencil from gasketing to the PCB surface. A relief-step pocket around the vias prevents this situation.

Relief for Paste (Two Print Stencil): The Two Print Stencil is used to print solder paste on a board which already has solder bricks on the PCB surface from a previous print cycle. An example would be a 12 mil thick glue stencil with an 8 mil deep relief-step pocket around SMT solder paste bricks.

AMTX 3-D™ Stencils


Electroformed stencils can be manufactured with deep relief-step pockets on the PCB side of the stencils. This stencil thickness is uniform (6 mils for example) even though the step-relief pocket can be as deep as 30 mils. Thus, the term 3D AMTX E-FAB is used to describe this stencil technology.
  • PCB BGA Package with Chip Devices in the Center of the Package: 3D AMTX E-FAB step stencil with a relief-step pocket 30 mils deep to give clearance for the Chip Devices while the stencil is 6 mils thick for printing solder paste for flux on the BGA pad sites.
  • PCB has a Raised Heat Sink in the Board's Surface: The 3D AMTX E-FAB stencil has a 20 mil deep relief-step pocket to provide clearance around the heat sink.

Step Design Guidelines

  • Squeegee Step-Up
  • 35 mils / mil of step

  • Squeegee Step-Down
  • 35 mils / mil of step

  • Contact Side Step-Up
  • 25 mils

  • Contact Side Step-Down
  • 25 mils
Electroform Stencil - step Electroform Stencil - step