SMT Stencil Manufacturing
Laser-cut · electroformed · step · nano-coated
Framed SMT Stencils
Permanent frame · mesh tensioning · volume production
- Permanent frame
- Smooth aperture walls
- Double bonding
- Fiducials
Unframed SMT Stencils
Removable foil · reusable frame · prototypes and small batches
- Removable stencil foil
- Reusable frame
- Machine and manual printing
- Prototypes and small batches
SMT Stencil Manufacturing Specifications
Custom frames, oversized formats and special coatings reviewed on request.
| Item | Specification |
|---|---|
| Stencil type | Framed (glue-in) stencils, unframed foils |
| Stencil material | Stainless-steel foil (standard), nickel (electroformed), Kapton / PET for hand printing |
| Foil thickness | 0.08 / 0.10 / 0.12 / 0.15 / 0.20 mm |
| Common framed sizes | 370×470, 420×520, 450×550, 550×650, 584×584 mm |
| Polishing | Grinding polish (standard), electrolytic polish (option, improves paste release) |
| Layers produced | Top, bottom, or top+bottom on one stencil / on separate stencils |
| Coating | Optional nano-coating to cut wipe frequency and extend service life |
| Input files | Gerber RS-274X (paste + solder mask + outline layers), ODB++, DXF |
| Order quantity and quotation | Confirmed after review of Gerber data, quantity and process requirements |
Stencil Aperture Design Reference
| Component | Pitch | Pad | Aperture | Foil thickness | Area ratio |
|---|---|---|---|---|---|
| QFP | 0.65 mm | 0.35 mm | 0.30–0.31 mm | 0.15–0.18 mm | 0.69–0.85 |
| QFP | 0.50 mm | 0.25 mm | 0.22–0.24 mm | 0.12–0.14 mm | 0.66–0.83 |
| QFP | 0.40 mm | 0.20 mm | 0.19–0.20 mm | 0.10–0.12 mm | 0.68–0.85 |
| QFP | 0.30 mm | 0.18 mm | 0.15 mm | 0.07–0.09 mm | 0.72–0.93 |
| BGA | 1.27 mm | ⌀0.80 mm | ⌀0.75 mm | 0.15–0.18 mm | 1.04–1.25 |
| BGA | 0.80 mm | ⌀0.40 mm | ⌀0.38 mm | 0.10–0.12 mm | 0.79–0.95 |
| BGA | 0.50 mm | ⌀0.28 mm | ⌀0.26 mm | 0.08–0.09 mm | 0.72–0.81 |
| 0402 | — | 0.25 mm | 0.55 × 0.25 mm | 0.08–0.13 mm | 0.66–1.07 |
| 0201 | — | 0.15 mm | 0.35 × 0.15 mm | 0.05–0.07 mm | 0.75–1.05 |
Related specifications:manufacturing capabilities and tolerance standards; related service:PCBA assembly service.
Values are common reference ranges; the released stencil data after engineering review governs the actual apertures.
Stencil Printing vs Digital/Jet Printing: How to Choose
| Criterion | Stencil printing | Digital / jet printing |
|---|---|---|
| Batch size | Stable, high-volume production | Prototypes, ultra-low volume, high-mix lines |
| Changeover cost | One stencil to cut per board type | No stencil to cut — changeover is a program change |
| Paste consistency | One stroke across the board — uniform | Paste can be tuned per pad |
| Cycle time & equipment | Fast cycle, widely available equipment | Slower cycle, costlier equipment |
How to Choose an SMT Stencil for Your Production Scenario
Production scenario · recommended build · project review
| Scenario | Recommended build | Notes |
|---|---|---|
| Prototype / hand printing | Stencil type, thickness and apertures confirmed during data review | Suitable for prototypes and small batches; material, thickness and alignment method are confirmed during data review. |
| Volume SMT production | Reviewed against equipment and repeat-printing requirements | Suitable for repeat printing with a fixed frame; structure and alignment requirements are confirmed against the equipment and data. |
| Fine-pitch / micro components | Reviewed against fine-pitch design and customer data | An option for fine-pitch designs; available material, apertures and thickness are confirmed from the customer data. |
| Mixed paste volumes on one board | Multilayer / step stencil | Different thickness zones on one stencil let large connector pads take more paste while fine-pitch areas take less. |
| Long runs with less wiping | Nano-coated stencil | The paste-repellent coating reduces residue in the apertures, stretching wipe intervals and stabilising transfer efficiency. |
How We Make Your SMT Stencil
- 1
Paste-layer data review
We extract the paste layer from your Gerber or ODB++ data, cross-check it against pads and solder-mask openings, and flag missing fiducials or outline edges.
- 2
Aperture design and area-ratio check
Area ratio and aspect ratio are reviewed group by group against component pitch. Exact thresholds, aperture sizes and foil thickness are confirmed during engineering review against the customer data and equipment.
- 3
Laser cutting or electroforming
Laser cutting, electroforming and other process options are confirmed after review of the Gerber data, pad layout, material, thickness and equipment.
- 4
Polishing and coating
Polishing, coating and other finishing options are confirmed per project against the apertures, material and transfer requirements.
- 5
Tensioning and framing
Stencil structure, tensioning and framing are confirmed against the equipment, board design and delivery requirements; suitability of an unframed option is also reviewed per project.
- 6
Dimensional inspection and shipping
We sample-check critical aperture dimensions and positional deviation, confirm the fiducials are clean and free of burrs, then pack and ship. Stencils tied to a PCBA order can ship together with the boards.
Stencil Printing Defects and What to Do About Them
| Symptom | Likely cause | What to do |
|---|---|---|
| Insufficient paste / incomplete release | Area ratio below 0.66, rough aperture walls, or dried paste left in the apertures. | Move to a thinner foil or enlarge apertures to raise the area ratio, add electrolytic polishing or nano-coating, and shorten wipe intervals. |
| Bridging | Apertures larger than the pads, a gap between stencil and board, or too fast a separation speed. | Keep apertures 5%–10% smaller than the pads for standard parts, check board support and print force, and slow the separation. |
| Paste offset from pads | Blurred or missing fiducials, or no fiducial-based alignment between stencil and PCB. | Keep clean fiducials on the paste layer and switch to framed stencils with automatic printer alignment for volume runs. |
| Uneven deposit thickness | Lost stencil tension, a worn squeegee, or mixed paste-volume requirements on one board. | Check tension and squeegee condition regularly; for mixed boards move to a multilayer step stencil to control paste per zone. |
Frequently asked questions
What is stencil printing in SMT?
- Solder paste transfer through stencil apertures onto PCB pads.
Is an SMD stencil the same as a surface mount stencil?
- Yes. These names refer to solder-paste stencils.
How do I choose SMT stencil thickness?
- Submit paste, mask and outline layers; thickness, apertures and area ratio confirmed by engineering.
Should aperture sizes exactly match the PCB pads?
- Reviewed against pads, pitch, paste and equipment.
Framed or unframed — which should I order?
- Confirmed against usage frequency, board design and equipment.
Are electroformed stencils better than laser-cut ones?
- Laser or electroforming process reviewed against fine-pitch design and customer data.
What files do you need to make a stencil?
- Paste · mask · outline; Gerber RS-274X, ODB++ or DXF. Include panelisation and fiducial requirements.
Can SMT stencils be reused, and how should they be stored?
- Yes. Check apertures, tension and fiducials after cleaning; replace worn or deformed stencils.
Are you an SMT stencil manufacturer?
- Laser cutting, polishing, tensioning and inspection at the Huizhou factory.
Are PCB and SMT stencils different? Are microelectronics stencils available?
- PCB and SMT stencils refer to the same product; microelectronics stencils quoted after drawing review.
Will the stencil ship with my PCBA order?
- Yes. Specify shipment with boards and packaging requirements when ordering.
Stencil printing vs digital/jet printing in SMT: which should I use?
- Stencil printing for volume production; jet printing reviewed for small batches or per-pad adjustment.