SMT

Stepped Stencil vs. Two-Pass Printing

How stepped stencil design eliminates extra passes and boosts production efficiency in SMT.
stepped stencil frames
As PCBs become more complex, with a growing mix of component sizes and solder paste volume requirements, surface mount manufacturers are often faced with a choice: use a stepped stencil or run multiple print passes to deposit solder paste accurately.
While both methods can deliver results, stepped stencils offer clear advantages in speed, consistency, and long-term efficiency.
Stepped stencils are manufactured by selectively removing material to create recessed areas, while maintaining the original thickness across the rest of the stencil.

Scale Up SMT Production

A standard stencil will either over-paste the small parts or under-paste the large pads. The traditional fix? Print once with a fine-pitch stencil, clean it, swap to a thicker stencil, and print again – or run two print passes with different squeegee pressure and aperture strategies.
uniform stepped stencil
With a stepped stencil, you solve this with one stencil, one pass, saving minutes per board – which scales up significantly in a production environment.
A stepped stencil integrates multiple thicknesses into a single stencil to accurately control solder paste volumes for both large and small components on the same PCB. This approach ensures reliable solder joints across varying component sizes. These stencils can be engineered with step features on the PCB side, the squeegee side, or both, depending on the application and component layout.

Step-Down (Partial Thinning) reduces paste volume for fine-pitch components to prevent bridging and short circuits. Ideal when most components are large, but a few fine-pitch parts require less paste. Material is removed from a thicker base (e.g., 0.15 mm down to 0.1 mm), creating recessed areas while keeping the stencil flat against the PCB.

multi level stepped stencil

When to use Stepped Stencils

1. Coplanarity Compensation When dealing with components like plugs and sockets that have varying heights, stepped stencils can resolve coplanarity issues by allowing for thicker paste deposits in specific areas to ensure proper contact, and address and correct variations in height or flatness between multiple contact points, surfaces, or components ensuring they all lie in the same geometric plane.
2. High Component Mix Boards

Boards with a mix of components requiring both high and low paste volumes benefit from step stencils.

3. PCB Surface Elevations

If a PCB includes coatings, labels, or solder mask bumps, stepped stencils with cavities on the underside help maintain proper stencil contact during printing. These are typically created using techniques like milling or step etching.

Stepped StencilTwo-Pass Printing
Print Time1 pass2 passes
AccuracyOne alignmentRisk of misalignment
SetupSimpleMultiple programs/stencils
CostMedium (once)Lower stencil, higher process
Best ForHigh-mix, productionLow-volume, R&D

Key Benefits of Mutli-level Stepped Stencils in SMT Assembly

  • Optimised Solder Paste Volume
    Stepped stencils enable precise control over paste deposition, ensuring each pad receives the exact amount of solder needed – critical for assemblies with a mix of fine-pitch and high-mass components.
  • Enhanced Print Quality
    By varying stencil thickness across the board, stepped stencils promote consistent paste release. This minimises common defects such as solder bridging, insufficient fill, or paste smearing – even on complex geometries.
  • Elimination of Multiple Print Passes
    Forget swapping stencils or running extra print cycles. A stepped stencil consolidates everything into a single print pass, streamlining your process and reducing operator involvement.
  • Lower Costs, Higher Efficiency
    By reducing downtime, eliminating extra stencil sets, and cutting down on rework, stepped stencils help drive down total production costs and improve throughput.
  • Greater Reliability in Assembly
    Accurate paste volumes lead to stronger, more reliable solder joints – particularly important in mission-critical sectors like automotive, aerospace, and medical electronics.
  • Versatile Step Design
    Whether you need step-downs for fine-pitch ICs or step-ups for thermal pads, stepped stencils can be engineered to match your exact component layout and volume requirements.
  • Fully Customisable
    From aperture layout to step positioning, every stepped stencil can be tailored to your specific board design – ensuring optimal performance for even the most complex assemblies.

Ready to Step Up Your Stencil Performance?

As electronic components continue to shrink and PCB designs become more complex, the need for precise solder paste control is more critical than ever. Step stencils provide the flexibility to deliver the right paste height and volume exactly where it’s needed – ensuring optimal solder joints for mixed-technology assemblies.

For high-mix, high-value or time-sensitive builds, like automotive, medical, aerospace, or telecom, stepped stencils are the smarter long-term solution. Stepped stencils help manufacturers cut time, reduce errors, and build with confidence.

Print Smarter, Not Twice: Datum Stepped Foils

If you’re looking to streamline your SMT process, reduce defects, and achieve consistent solder paste volumes across complex boards, stepped stencils are the solution. At Datum we specialise in producing multi-level, micro-machined step foils in a single continuous operation-ensuring precision without distortion, burrs, or compromise for our stencil manufacturing clients.

Our micro-milling technology offers unmatched flexibility, allowing for custom shapes, profiles, and cavity designs tailored to your exact requirements.

Contact Datum today to discover how precision stepping can elevate your production.

Stepped Foils
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