Layer transition strategy in PCB Design - Cell-by-Cell Formula Trace

Concept Flow

Layer Transition Strategy Flow:

[Top Layer] --via--> [Inner1 Layer] --via--> [Inner2 Layer] --via--> [Bottom Layer]

Via Types:
- Through Via: connects Top to Bottom
- Blind Via: connects Top to Inner1 or Inner1 to Inner2 or Inner2 to Bottom

Costs:
Through Via = 5
Blind Via = 3

This flow shows how signals move through PCB layers using different via types. Through vias connect the top and bottom layers directly, while blind vias connect intermediate layers. Each via type has an associated manufacturing cost.

Formula

SUMX(FILTER(sample_data, sample_data[Start Layer] = "Top"), sample_data[Cost])

This formula sums the cost of all vias that start from the 'Top' layer by filtering rows where 'Start Layer' equals 'Top' and then summing their 'Cost' values.

Step-by-Step Trace

Step	Expression	Evaluates To	Explanation
1	FILTER(sample_data, sample_data[Start Layer] = "Top")	[Row 1, Row 2]	Filter rows where Start Layer is 'Top'. Rows 1 and 2 match.
2	SUMX([Row 1, Row 2], sample_data[Cost])	5 + 3 = 8	Sum the Cost values of filtered rows: 5 (Through Via) + 3 (Blind Via) = 8.

The final result is 8, the total cost of vias starting at the Top layer.

Variable Tracker

Variable	Value
Filtered Rows	Rows 1 and 2 (Start Layer = 'Top')
Costs in Filtered Rows	5 (Row 1), 3 (Row 2)
Sum of Costs	8

Key Moments

Which rows are selected when filtering for Start Layer = 'Top'?

What is the total cost calculated by the formula?

What does the SUMX function do in this formula?

Sheet Trace Quiz - 3 Questions

Which rows does the formula include when filtering Start Layer = 'Top'?

A Rows 4 and 5

B Only Row 2

C Rows 1 and 2

D All rows

Key Result

The layer transition strategy uses different via types to connect PCB layers. This example calculates the total cost of vias starting from the Top layer by filtering and summing costs.

Transcript

We start by filtering the data to find all vias that begin at the Top layer. This gives us two rows: one for a Through Via and one for a Blind Via. Next, we sum their costs, 5 and 3, to get a total cost of 8. This helps us understand the expense of using vias starting from the Top layer in PCB design.