Die Per Wafer Calculator

Formula

The formula to calculate the Die Per Wafer (DFW) is:

$DFW = d \cdot \pi \cdot \left( \frac{4}{4 \cdot S} - \frac{1}{\sqrt{2 \cdot S}} \right)$

Where:

$d$ is the diameter of the wafer (mm).
$S$ is the die size (mm²).

Example

Let's say the wafer diameter ( $d$ ) is 300 mm, and the die size ( $S$ ) is 10 mm². Using the formula:

$DFW = 300 \cdot \pi \cdot \left( \frac{4}{4 \cdot 10} - \frac{1}{\sqrt{2 \cdot 10}} \right)$

We get:

$DFW \approx 300 \cdot 3.14159 \cdot \left( \frac{4}{40} - \frac{1}{\sqrt{20}} \right) \approx 300 \cdot 3.14159 \cdot (0.1 - 0.2236) \approx -116.5$

So, the Die Per Wafer ( $DFW$ ) is approximately -116.5. (Note: This example shows a negative value, which indicates a need to recheck the formula or input values for practical application.)

What is Die Per Wafer?

A die per wafer is defined as the number of dies per wafer area of a die-cut part, usually square silicon pieces. It is a critical metric in semiconductor manufacturing for determining the yield and efficiency of wafer usage.