Clearance rules for different nets in PCB Design - Real Business Scenario

Scenario Mode

👤 Your Role: You are a PCB design engineer working on a complex multi-layer board.

📋 Request: Your manager wants you to analyze and report the clearance rules applied between different nets to ensure signal integrity and manufacturing reliability.

📊 Data: You have a dataset listing pairs of nets, their assigned clearance rules in mils, and the net types (e.g., power, signal, ground).

🎯 Deliverable: Create a report showing clearance rules between net pairs, highlighting any that do not meet the minimum required clearance standards.

Sample Data

Net1	Net1_Type	Net2	Net2_Type	Clearance_mils
VCC	Power	GND	Ground	10
VCC	Power	Signal1	Signal	8
Signal1	Signal	Signal2	Signal	6
GND	Ground	Signal2	Signal	7
VCC	Power	Signal3	Signal	5
Signal3	Signal	Signal4	Signal	4
GND	Ground	Signal4	Signal	6
Signal2	Signal	Signal3	Signal	3

1

Step 1: Load the clearance rules data into your BI tool.

Import the table with columns: Net1, Net1_Type, Net2, Net2_Type, Clearance_mils.

Expected Result

Data table with 8 rows loaded correctly.

2

Step 2: Create a calculated column to identify if clearance meets minimum standards based on net types.

Define minimum clearance rules: Power-Ground = 10 mils, Power-Signal = 8 mils, Signal-Signal = 5 mils, Ground-Signal = 6 mils. Use a formula to check if Clearance_mils >= minimum required clearance for the net pair.

Expected Result

New column 'Meets_Standard' with TRUE or FALSE for each row.

3

Step 3: Create a summary table showing counts of net pairs that meet or fail clearance standards.

Group by 'Meets_Standard' and count rows.

Expected Result

Summary showing how many pairs meet and how many fail the clearance rules.

4

Step 4: Build a dashboard visualization with a bar chart showing clearance values per net pair and color code by 'Meets_Standard'.

X-axis: Net1-Net2 pairs, Y-axis: Clearance_mils, Color: Meets_Standard (green for TRUE, red for FALSE).

Expected Result

Bar chart clearly showing which net pairs pass or fail clearance rules.

5

Step 5: Add a table visual listing all net pairs that fail clearance standards for detailed review.

Filter data where 'Meets_Standard' = FALSE.

Expected Result

Table with net pairs and their clearance values below minimum standards.

Final Result

Clearance Rules Dashboard

+-----------------------------+
| Net Pair | Clearance | Pass |
+-----------------------------+
| VCC-GND  |    10     | Yes  |
| VCC-Signal1 |     8     | Yes  |
| Signal1-Signal2 |     6     | Yes  |
| GND-Signal2 |     7     | Yes  |
| VCC-Signal3 |     5     | No   |
| Signal3-Signal4 |     4     | No   |
| GND-Signal4 |     6     | Yes  |
| Signal2-Signal3 |     3     | No   |
+-----------------------------+

Bar chart colors: Green=Pass, Red=Fail

✓Most power to ground and power to signal clearances meet the minimum standards.

✓Several signal to signal clearances are below the required minimum, which may cause signal integrity issues.

✓Clearance between Signal2 and Signal3 is the lowest and fails the standard, requiring design review.

Bonus Challenge

Create a heatmap visualization showing clearance values between all net types combinations to identify critical areas quickly.

Show Hint

Use a matrix visual with Net1_Type on rows, Net2_Type on columns, and average Clearance_mils as values. Apply conditional formatting to highlight low clearance.