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Step Stencils

 

Offers Significant Flexibility in Achieving the Proper Height and Volume

Photo Stencil's 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. Available in all stencil technologies; Electroformed, Laser Cut and Chemical Milled. Photo Stencil are pioneers in the field of Step Stencil technology with all process contained in house for the most comprehensive service available in the industry. 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.

Application

Maximum flexibility for achieving correct solder paste height and volume in challenging applications.

Advantages

  • Available as ‘step up’ and ‘step down’ squeegee side, ‘step up’ PCB side or on both sides.
  • Ideal for providing bar code relief and thus maintaining the maximum gasket.
  • Matched Slit squeegee blades allow for flexure over the raised pocket areas.
  • Match with Photo Stencils range of E-Blade™ squeegees for maximum life and performance.
  • Multi-thickness steps available.
  • As with all Photo Stencil metal stencils available with SmartRelease nano coating technology.