Stencil Area Ratio Calculator

Are you trying to calculate stencil area ratio quickly? The Stencil Area Ratio Calculator is a useful tool that can help you to find stencil area ratio by entering a few values, aperture length, width and stencil thickness into the calculator.

Stencil Area Ratio Calculator

Enter any 3 values to calculate the missing variable

What is Stencil Area Ratio?

The Stencil Area Ratio (SAR) is one of the measures to evaluate how appropriate a given stencil would be for transferring solder paste in electronic manufacturing. It would define what could be achieved by the given stencil when a balance exists between the size of the aperture and the thickness of the stencil for an optimum level of performance.

How to Use the Calculator

To use the calculator, input the required values in the specified fields:

Example input values:

Input Example Value
Aperture Length 1.2 mm
Aperture Width 0.8 mm
Stencil Thickness 0.15 mm

How to Calculate Stencil Area Ratio

The formula to calculate the Stencil Area Ratio (SAR) is:

SAR=(L×W)2×(L+W)×T\text{SAR} = \frac{(L \times W)}{2 \times (L + W) \times T}


SAR  Stencil Area Ratio
L  Length of the aperture
W  Width of the aperture
T  Thickness of the stencil

1. First, multiply the length (L) and width (W) of the aperture:

L×WL \times


1.2mm×0.8mm=0.96mm21.2 \, \text{mm} \times 0.8 \, \text{mm} = 0.96 \, \text{mm}^2

2. Next, calculate the sum of the length and width, then multiply by 2:

2×(L+W)2 \times (L + W)


2×(1.2mm+0.8mm)=2×2mm=4mm2 \times (1.2 \, \text{mm} + 0.8 \, \text{mm}) = 2 \times 2 \, \text{mm} = 4 \, \text{mm}

3. Finally, divide the result from step 1 by the product of step 2 and the stencil thickness (T):

SAR=(L×W)2×(L+W)×T\text{SAR} = \frac{(L \times W)}{2 \times (L + W) \times T}


0.96mm24mm×0.15mm=0.96mm20.6mm2=1.6\frac{0.96 \, \text{mm}^2}{4 \, \text{mm} \times 0.15 \, \text{mm}} = \frac{0.96 \, \text{mm}^2}{0.6 \, \text{mm}^2} = 1.6

Calculation Examples

1. Basic Example

Input Value
Aperture Length 1.2 mm
Aperture Width 0.8 mm
Stencil Thickness 0.15 mm
Stencil Area Ratio 1.6

2. Advanced Example

Let’s consider a more complex scenario where you have different aperture sizes and stencil thicknesses.

Input Value
Aperture Length 2.0 mm
Aperture Width 1.5 mm
Stencil Thickness 0.2 mm
Stencil Area Ratio 1.25


What is a good Stencil Area Ratio?

A good stencil area ratio is typically greater than 1.5. Ratios below this value may not transfer solder paste well.

Why is the Stencil Area Ratio important?

It ensures proper solder paste transfer within the area, thereby preventing faults in electronic components.

Can I use the calculator for different units?

The calculator has been set up for mm. Convert values as necessary if other units are used.

Final Thoughts

I hope you found the Stencil Area Ratio Calculator and this guide helpful. Please share your experience using the tool and feel free to ask any questions you might have. Your feedback is valuable and helps improve the tool for others.

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