Thermal spoke connections in PCB Design - Cell-by-Cell Formula Trace

Sample Data

This data shows pad sizes, thermal spoke widths, and number of spokes for PCB thermal connections. The goal is to calculate the total thermal area for each pad.

Cell	Value
A1	Pad Size (mm)
B1	Thermal Spoke Width (mm)
C1	Number of Spokes
D1	Total Thermal Area (mm²)
A2	2.0
B2	0.3
C2	4
D2
A3	3.0
B3	0.4
C3	6
D3

Formula Trace

=C2 * B2 * (A2 / 2)

Step 1: A2 / 2

Step 2: B2 * (A2 / 2)

Step 3: C2 * B2 * (A2 / 2)

Cell Reference Map

     A       B       C       D
1 | Pad Size | Spoke W | Spokes | Total Area
2 |   2.0    |  0.3    |   4    | 
3 |   3.0    |  0.4    |   6    | 

References used: A2 (Pad Size), B2 (Spoke Width), C2 (Number of Spokes) for row 2 calculation.

The formula uses cells A2, B2, and C2 to calculate the total thermal area in D2.

Result

     A       B       C       D
1 | Pad Size | Spoke W | Spokes | Total Area
2 |   2.0    |  0.3    |   4    |  1.2
3 |   3.0    |  0.4    |   6    | 

The total thermal area for the first pad is calculated as 1.2 mm².

The result 1.2 mm² appears in cell D2, showing the total thermal area for the thermal spokes connected to the pad.

Sheet Trace Quiz - 3 Questions

What is the value of half the pad size in step 1?

A 2.0

B 0.3

C 1.0

D 4

Key Result

Total thermal area = Number of spokes * Spoke width * (Pad size / 2)