SMD-Stencils are precision tools which have to comply with high requirements, as they take a key role in the SMT (surface mount technology) process. We offer following SMD-Stencils:

Solder paste stencils are used to apply solder depots on printed circuit boards with a screen printing technique. SMD components (SMD = surface mounted device) are placed within these depots subsequently and soldered with a following reflow- or vapor phase process.

Stencils for adhesives are primarily used for mixed assembly, as substitution for a dispenser, and are necessary before component mounting and wave soldering.

Our lasered SMD-Stencils (made of stainless steel) allow a precise placement and strenght-of-shape of the solder- / adhesive- depots on the PCB and therefore accomodate the small track-widths and spacings as well as the hightech multipin components. Our SMD-Stencils are perfectly suited for finepitch and BGA assembly.

Terms in this Design-Aid:
top side = squeegee side, top view
bot side = opposite side of squeegee, bottom view
aperture = hole in the stencil, stencil pad

Stencil requirements

The quality of the finished assembly is influenced by the SMD-Stencil used. The size of the apertures (openings), and thickness of the stencil determine the amount and shape of the applied paste.

The purpose of the SMD-Stencil is:

  1. Precise application of the needed material (solder paste, glue)
  2. Creation of depots defined in shape and size
  3. Reproducibility of the print
  4. Effective cleaning of the pads
  5. Economy

The stencil data (necessary openings = apertures) is generated from the PCB data supplied (on request with pad reduction) or completed by the customer.

To ensure an optimum result for the production of your SMD-Stencils, please note the following design hints.

Stencil thickness

For the choice of the stencil thickness (for solder paste), you can adhere to the following guidelines. Decisive is always the smallest component used. The final say should always have your assembler!

Type Pitch typical stencil thickness
  mm µm
BGA 1,25 150 – 200
Finepitch BGA 1,00 115 – 135
Finepitch BGA 0,50 75 – 125
0402   125 – 150
0201   75 – 125
01005   65 – 90
PLCC 1,25 150 – 250
QFP 0,65 150 – 175
QFP 0,50 125 – 150
QFP 0,40 100 – 125
QFP 0,30 75 – 125
The stencil thickness shown is rounded down and adjusted to suit the available material thicknesses! The standard thickness is 150μm.

Detection by aspect ratio and area ratio

The calculation of necessary stencil thickness can also be made via aspect ratio and area. Recommended values:

  leaded leadfree
Aspekt ratio >1,5 >1,7
Area ratio >0,66 >0,8
SMD stencil thickness calculation by aspect ratio and area ratio

The thickness of stencils for adhesive is usually 250µm.

Processing of the stencil pads

Generally we recommend a reduction of the stencil pads (apertures) by 10%. This could be the done by the customer (with export of the paste data) or is done by us on request.

The following pad operations are carried out by Multi-CB on request:

  • Reduction of the pads by up to 10%
  • Absolute circular reduction of the pads

Modification of the pad form

Generally, you should (along with your assembly) make a decision in respect of angular or rounded pads.

If you have relatively large pad areas in your design, adding outbreak grids to apertures can help to reduce the adhesive forces.

SMD pad possible changes
Possible changes of the pad form.

Text on the stencil

At Multi-CB 100 characters of text are inclusive (more text is feasible for a small fee). The text can be produced half lasered and lasered.

Half lasered text

Stencils are generally lasered from the bottom-side. The production-related conical cross-section is then wider on the side opposite to the squeegee and allows a better peeling after the aplication of solder paste / adhesive (glue). Half lasered text is thus on the bottom side of the stencil.

Lasered text

As the half lasered text, also the lasered text is cut from the bottom side. You can decide whether the text is readable from the bottom or top side. To ensure best stability, lasered text is executed in a special font which prevents breaking out of the letters.

Font for lasered text of a SMD stencil
Font for lasered text

Placement of PCB data

If we get no information regarding data placement from the customer, the PCB data is placed based on the available data centrally on the stencil. Thus based on the board outline, or the pads (copper). If a different placement is wished, please let us know when ordering (text, sketch).

When ordering your stencil along with your PCB, you ideally have the stencil data already integrated in the digital production data and placed a note in your order to notify us

Examples of default layers for stencil data.

  • EAGLE: tCream, bCream
  • Target: PasteTop, PasteBot
  • Protel: GTP, GTB

Stencil holder

On request, we can add the required perforation to your stencil for all established, licence-free quick clamping frames / holders.

Possible systems are amanongs others:

  • QuattroFlex
  • ZelFlex
  • ...

In this case, please send us the data sheet of the quick clamp together with your order or contact us.


Attribute Tolerance
Position accuracy +/- 5µm
Accuracy of pad geometry +/- 8µm

IPC handbook

In the IPC-design directive for SMD stencils (IPC-7525A) is mentioned, as other applicable policy for the cleaning of stencils and misprinted printed circuit boards, IPC-7526 (Stencil and Misprinted Cleaning Handbook).

This Directive is not commercially available and can be downloaded for free.

IPC-7526 – free download

Our service

In the production of our SMD laser stencils, we place great value on 100% quality. That's why we measure all the pads for dimensional accuracy and the real presence of the pads after production of your SMD stencil.

Registration marks

The application of registration / fiducial marks ensures the correct positioning of the stencil to the PCB, by the vision system of the assembly company.

For vision systems operating from below, the registration marks are usually half-lasered. This is possible because SMD stencils are generally lasered from below.

Does the vision system of the assembly company work from above, the registration marks are lasered through, just like a normal pad.

The number of registration marks is specified by the customer, per single PCB usually 3-4 pieces.

Typical types of registration marks:

SMD stencil registration mark examples.

Finishing treatment

  • Inclusive: Finish treatment by double-sided brushing of the surface in all four directions, giving reduction of the surface roughness Rz to about 1µm.
  • Surcharge for: Electropolish (good for middle series) and Nano protection (big series. See SMD-Stencil finishing treatment.