Zone priority for overlapping fills in PCB Design - Cell-by-Cell Formula Trace

Sample Data

This data represents three overlapping copper fill zones on a PCB. Each zone has a name, a priority number (lower number means higher priority), and the area it covers in square millimeters.

Cell	Value
A1	Zone Name
B1	Priority
C1	Area (sq mm)
A2	Zone 1
B2	1
C2	50
A3	Zone 2
B3	2
C3	30
A4	Zone 3
B4	3
C4	20

Formula Trace

MAXX(FILTER(Zones, Zones[Area (sq mm)] > 0), Zones[Priority])

Step 1: FILTER(Zones, Zones[Area (sq mm)] > 0)

Step 2: MAXX([Zone 1, Zone 2, Zone 3], Zones[Priority])

Cell Reference Map

    A         B         C
1 |Zone Name|Priority |Area    |
2 |Zone 1   |1        |50      |
3 |Zone 2   |2        |30      |
4 |Zone 3   |3        |20      |

The formula uses the Priority and Area columns from all zones to determine the highest priority number among zones with area greater than zero.

Result

    A         B         C         D
1 |Zone Name|Priority |Area    |Max Priority|
2 |Zone 1   |1        |50      |3          |
3 |Zone 2   |2        |30      |          |
4 |Zone 3   |3        |20      |          |

The result '3' in cell D2 shows the highest priority number among overlapping zones with area > 0, indicating Zone 3 has the lowest priority.

Sheet Trace Quiz - 3 Questions

Which zones are included when filtering by area > 0?

A Zone 1, Zone 2, Zone 3

B Zone 1 only

C Zone 2 and Zone 3 only

D No zones

Key Result

MAXX(FILTER(Table, Condition), Table[Priority]) finds the highest priority value among filtered rows.

Practice

1. What does zone priority control in PCB design when fills overlap?

easy

A. Which copper fill appears on top

B. The thickness of the copper fill

C. The color of the copper fill

D. The shape of the copper fill

Solution

1. Step 1: Understand overlapping fills

   When two copper fills overlap, one must appear above the other to avoid confusion.

2. Step 2: Role of zone priority

   Zone priority sets which fill is drawn on top by assigning a higher priority number.

3. Final Answer:

   Which copper fill appears on top -> Option A

4. Quick Check:

   Zone priority controls top fill display [OK]

Hint: Higher priority number means fill appears on top [OK]

Common Mistakes:

• Confusing priority with fill thickness
• Thinking priority changes fill color
• Assuming priority affects fill shape

2. Which of the following is the correct way to assign a higher priority to a zone fill in a PCB design tool?

easy

A. Set the zone priority number to a lower value

B. Set the zone priority number to a higher value

C. Change the zone fill color to a brighter shade

D. Increase the zone fill thickness

Solution

1. Step 1: Understand priority numbering

   Higher numbers mean higher priority, so the fill with the bigger number appears on top.

2. Step 2: Assigning priority

   To make a zone appear above others, assign it a higher priority number.

3. Final Answer:

   Set the zone priority number to a higher value -> Option B

4. Quick Check:

   Higher number = higher priority [OK]

Hint: Use bigger numbers for top zones [OK]

Common Mistakes:

• Using lower numbers for higher priority
• Changing color instead of priority
• Adjusting thickness instead of priority

3. Given two overlapping zones: Zone A with priority 5 and Zone B with priority 8, which zone will appear on top in the PCB layout?

medium

A. Zone A will appear on top

B. Neither zone will appear

C. Both zones will merge and appear equally

D. Zone B will appear on top

Solution

1. Step 1: Compare priority values

   Zone A has priority 5, Zone B has priority 8; higher number means higher priority.

2. Step 2: Determine which zone appears on top

   Zone B's priority 8 is greater than Zone A's 5, so Zone B appears on top.

3. Final Answer:

   Zone B will appear on top -> Option D

4. Quick Check:

   Priority 8 > 5 means Zone B on top [OK]

Hint: Higher priority number wins overlap [OK]

Common Mistakes:

• Choosing lower priority zone as top
• Assuming zones merge visually
• Ignoring priority numbers

4. You set two overlapping zones with the same priority number. What issue might occur in your PCB design?

medium

A. The zones will overlap without clear top fill, causing design errors

B. The zone with the larger area will automatically appear on top

C. The software will assign random priority to one zone

D. The zones will merge into a single fill automatically

Solution

1. Step 1: Understand equal priority effect

   When zones have the same priority, the software cannot decide which fill is on top clearly.

2. Step 2: Resulting issue

   This causes overlapping fills without clear layering, leading to design errors or confusion.

3. Final Answer:

   The zones will overlap without clear top fill, causing design errors -> Option A

4. Quick Check:

   Same priority causes unclear overlap [OK]

Hint: Avoid equal priorities for overlapping zones [OK]

Common Mistakes:

• Assuming larger area wins automatically
• Thinking software assigns random priority
• Believing zones merge automatically

5. You have three overlapping zones with priorities 3, 7, and 5. You want the zone with priority 3 to appear on top without changing the other zones' priorities. What is the best approach?

hard

A. Set the zone with priority 3 to a negative number

B. Decrease the priority of the zone with 7 to below 3

C. Increase the priority of the zone with 3 to a number higher than 7

D. Change the fill color of the zone with priority 3 to make it appear on top

Solution

1. Step 1: Understand priority rules

   Zones with higher priority numbers appear on top of lower ones.

2. Step 2: Achieve desired top zone

   To make the zone with priority 3 appear on top, increase its priority above 7.

3. Step 3: Avoid changing other zones

   Since other zones' priorities cannot be changed, only increase the target zone's priority.

4. Final Answer:

   Increase the priority of the zone with 3 to a number higher than 7 -> Option C

5. Quick Check:

   Higher priority number = top zone [OK]

Hint: Raise target zone priority above others [OK]

Common Mistakes:

• Trying to set negative priority
• Changing color instead of priority
• Lowering other zones' priorities when not allowed