Gerber intake
Read paste or copper pads; confirm fiducials and frame needs.
SMT stencil
PCB SMT Stencil
An SMT stencil controls paste volume. XFPCB fabricates laser-cut stencils and reviews apertures against your pad geometries so fine-pitch and large thermal pads print predictably.
Stencil Quality Shows Up in Yield
Wrong aperture reductions cause insufficient solder on BGAs or bridging on fine-pitch QFPs. XFPCB treats stencil design as part of assembly DFM, not a commodity cut.
Order stencils alone or with PCBA. Share Gerber paste layers or pad copper so we can propose thickness and reductions.
Stencil Workflow
Aperture engineering
Apply reductions for fine-pitch; keep volume on thermal pads.
Laser cut & clean
Cut stainless steel, clean, and verify critical openings.
Ship or use in-house
Deliver the stencil or retain it for XFPCB SMT printing.
Stencil Controls
- Thickness choice balances fine-pitch vs large pad volume - sometimes a step stencil is better.
- Fiducials on the stencil must match the board for accurate alignment.
- Nano-coating options can be discussed for fine-pitch paste release.
- Revision of stencil tracks the PCB revision.
Stencil Quotation Focus
| Project Area | XFPCB Guidance |
|---|---|
| Material | Stainless steel laser-cut foil |
| Design input | Paste Gerber preferred; copper pads acceptable |
| Options | Framed / frameless, step stencil, nano-coat |
| Use case | Prototype through production SMT |
Aperture DFM Checklist
Fine-Pitch Reductions
Openings are reduced appropriately to limit bridging on tight lead pitches.
Thermal Pad Windows
Large pads may use windowed apertures to control voiding.
Thickness Selection
Foil thickness is chosen from the mix of tiny and large pads on your board.
Useful Terms
- Aperture
- Opening in the stencil that defines paste deposit.
- Home-plate
- Common aperture shape reduction for rectangular pads.
- Step stencil
- Local thickness change for mixed pad sizes.
- Fiducial
- Optical alignment mark shared by board and stencil.
Related XFPCB Pages
PCB SMT Stencil FAQs
What file do you need for a stencil?
A paste-layer Gerber is ideal. If unavailable, copper pad layers plus a note on which pads are pasted can work.
Framed or frameless?
Framed stencils suit repeated production on printers; frameless can work for prototypes - tell us your printer type.
When do I need a step stencil?
When the board mixes very small and very large pads that cannot share one foil thickness cleanly.
Can the stencil ship with my PCBA order?
Yes. Many turnkey jobs include stencil fabrication used directly on our SMT line.
Request an SMT Stencil Quote
Send paste Gerbers and note fine-pitch or BGA packages so aperture rules are set correctly.
- Include board outline and fiducial positions.
- State framed vs frameless preference.
- Mention if the stencil will be used at XFPCB or shipped to you.