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:
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.)
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.
Formula: \( \text{DPW} = \frac{\pi \times (D/2)^2}{A_d} - \frac{\pi \times (D/2)^2}{A_d} \times \frac{d}{D} \)
Example: \( \text{DPW} = \frac{\pi \times (300/2)^2}{10} - \frac{\pi \times (300/2)^2}{10} \times \frac{1}{300} \)
Formula: \( \text{Gross Die} = \frac{\pi \times (D/2)^2}{A_d} \)
Example: \( \text{Gross Die} = \frac{\pi \times (200/2)^2}{5} \)
Formula: \( \text{Gross Die} = \frac{\pi \times (D/2)^2}{A_d} \)
Example: \( \text{Gross Die} = \frac{\pi \times (150/2)^2}{4} \)
