Manual trace routing in PCB Design - Cell-by-Cell Formula Trace

Sample Data

This data represents a simple PCB grid with pins and their net names, and coordinates for manual trace routing.

Cell	Value
A1	Pin1
B1	Pin2
C1	Pin3
A2	NetA
B2	NetB
C2	NetC
A3	Start
B3	Path
C3	End
A4	X=1,Y=1
B4	X=2,Y=1
C4	X=3,Y=1
A5	X=1,Y=2
B5	X=2,Y=2
C5	X=3,Y=2

Formula Trace

Route trace from Pin1 (X=1,Y=1) to Pin3 (X=3,Y=1) manually by connecting cells A4 -> B4 -> C4

Step 1: Start at A4 (X=1,Y=1)

Step 2: Move from A4 to B4 (X=2,Y=1)

Step 3: Move from B4 to C4 (X=3,Y=1)

Step 4: Trace path: A4 -> B4 -> C4

Cell Reference Map

   A       B       C  
1 Pin1    Pin2    Pin3
2 NetA    NetB    NetC
3 Start   Path    End 
4 X=1,Y=1->X=2,Y=1->X=3,Y=1
5 X=1,Y=2  X=2,Y=2  X=3,Y=2

The routing references cells A4, B4, and C4 representing the coordinates for the manual trace path.

Result

   A       B       C  
1 Pin1    Pin2    Pin3
2 NetA    NetB    NetC
3 Start   Path    End 
4  ●  ---->  ●  ---->  ● 
5          (empty)      

The visual shows the manual trace routing as a path of connected points from Pin1 to Pin3 horizontally across the grid.

Sheet Trace Quiz - 3 Questions

Which cells represent the manual trace path from Pin1 to Pin3?

A A2, B2, C2

B A5, B5, C5

C A4, B4, C4

D A1, B1, C1

Key Result

Manual trace routing connects sequential coordinate cells step-by-step to form a continuous path.

Practice

1. What is the main purpose of manual trace routing in PCB design?

easy

A. To draw exact paths for electrical connections on the board

B. To automatically place components on the PCB

C. To generate a 3D model of the PCB

D. To simulate the electrical signals on the board

Solution

1. Step 1: Understand manual trace routing

   Manual trace routing means drawing the exact paths for electrical connections yourself, not letting software do it automatically.

2. Step 2: Identify the main goal

   The goal is to control how traces run on the PCB to ensure proper electrical performance and fit.

3. Final Answer:

   To draw exact paths for electrical connections on the board -> Option A

4. Quick Check:

   Manual trace routing = drawing exact paths [OK]

Hint: Manual routing means you draw paths yourself, not auto-routing [OK]

Common Mistakes:

• Confusing manual routing with automatic component placement
• Thinking it simulates signals instead of routing traces
• Assuming it creates 3D models

2. Which of the following is the correct step to start manual trace routing in most PCB design software?

easy

A. Click 'Auto-Route' and wait for the software to finish

B. Select the 'Route' tool and click on the pad to start the trace

C. Place components randomly before routing

D. Export the design to a PDF before routing

Solution

1. Step 1: Identify the manual routing tool

   Manual routing usually starts by selecting the 'Route' or 'Trace' tool in the software.

2. Step 2: Begin trace from a pad

   You click on a pad or pin to start drawing the trace manually.

3. Final Answer:

   Select the 'Route' tool and click on the pad to start the trace -> Option B

4. Quick Check:

   Manual routing starts with 'Route' tool and pad click [OK]

Hint: Start manual routing by selecting 'Route' tool and clicking pad [OK]

Common Mistakes:

• Choosing auto-route instead of manual routing
• Placing components randomly before routing
• Exporting design before routing

3. Consider you manually route a trace from pad A to pad B on a PCB. If the trace width is set too narrow, what is the most likely outcome?

medium

A. The trace may overheat or cause signal loss

B. The trace will automatically widen during manufacturing

C. The trace will handle higher current safely

D. The trace will be invisible in the final design

Solution

1. Step 1: Understand trace width impact

   Narrow traces have higher electrical resistance and less current capacity.

2. Step 2: Predict consequences of narrow trace

   This can cause overheating or signal degradation due to insufficient width.

3. Final Answer:

   The trace may overheat or cause signal loss -> Option A

4. Quick Check:

   Narrow trace = risk of overheating and signal loss [OK]

Hint: Narrow traces risk overheating and signal loss [OK]

Common Mistakes:

• Thinking narrow traces handle more current
• Assuming trace width changes automatically
• Believing trace becomes invisible

4. You manually routed a trace but notice it overlaps another trace causing a short circuit. What is the best way to fix this?

medium

A. Increase the trace width to cover the overlap

B. Ignore it; the software will fix it automatically

C. Delete the overlapping trace and reroute it carefully

D. Export the design and fix the error in a different software

Solution

1. Step 1: Identify the problem

   Overlapping traces cause shorts, which must be fixed manually.

2. Step 2: Correct the routing

   Deleting the overlapping trace and rerouting it carefully avoids shorts and keeps the board clean.

3. Final Answer:

   Delete the overlapping trace and reroute it carefully -> Option C

4. Quick Check:

   Fix shorts by deleting and rerouting traces [OK]

Hint: Fix shorts by deleting and carefully rerouting traces [OK]

Common Mistakes:

• Assuming software auto-fixes shorts
• Increasing width causes more shorts
• Exporting to fix errors elsewhere

5. You need to manually route traces on a high-speed PCB with sensitive signals. Which practice helps ensure signal integrity during manual trace routing?

hard

A. Place vias randomly to speed up routing

B. Use the narrowest possible trace width everywhere

C. Route all traces as close as possible to each other

D. Keep trace lengths matched and avoid sharp corners

Solution

1. Step 1: Understand high-speed signal needs

   High-speed signals require careful routing to avoid delays and interference.

2. Step 2: Apply best routing practices

   Matching trace lengths prevents timing issues; avoiding sharp corners reduces signal reflections.

3. Final Answer:

   Keep trace lengths matched and avoid sharp corners -> Option D

4. Quick Check:

   Matched lengths and smooth traces preserve signal integrity [OK]

Hint: Match trace lengths and avoid sharp corners for signals [OK]

Common Mistakes:

• Using narrow traces everywhere causing current issues
• Routing traces too close causing crosstalk
• Placing vias randomly causing signal disruption