Gerber file generation in PCB Design - Real Business Scenario

Scenario Mode

👤 Your Role: You are a PCB design engineer at an electronics manufacturing company.

📋 Request: Your manager wants you to prepare the Gerber files for the latest PCB design so the manufacturing team can start production.

📊 Data: You have the PCB layout data including layers for copper, solder mask, silkscreen, drill holes, and board outline.

🎯 Deliverable: A complete set of Gerber files for each PCB layer and a drill file, organized and named correctly for manufacturing.

Sample Data

Layer	Description	File Format	Example File Name
Top Copper	Top copper traces and pads	.gbr	board_top_copper.gbr
Bottom Copper	Bottom copper traces and pads	.gbr	board_bottom_copper.gbr
Top Solder Mask	Top solder mask openings	.gbr	board_top_soldermask.gbr
Bottom Solder Mask	Bottom solder mask openings	.gbr	board_bottom_soldermask.gbr
Top Silkscreen	Top layer text and markings	.gbr	board_top_silkscreen.gbr
Bottom Silkscreen	Bottom layer text and markings	.gbr	board_bottom_silkscreen.gbr
Drill File	Drill hole locations and sizes	.drl	board_drill.drl
Board Outline	PCB edge profile	.gbr	board_outline.gbr

1

Step 1: Open your PCB design software and load the latest PCB project file.

No formula needed; just open the project file.

Expected Result

The PCB layout with all layers is visible and ready for export.

2

Step 2: Go to the export or fabrication output section and select Gerber file generation.

Select layers: Top Copper, Bottom Copper, Top Solder Mask, Bottom Solder Mask, Top Silkscreen, Bottom Silkscreen, Board Outline.

Expected Result

All required layers are selected for Gerber export.

3

Step 3: Configure the Gerber file settings: set units to millimeters, format to 2:5 (2 digits before decimal, 5 after), and enable RS-274X format.

Units=mm; Format=2:5; Gerber format=RS-274X.

Expected Result

Gerber files will be generated with correct precision and format.

4

Step 4: Generate the drill file with the correct drill sizes and positions in Excellon format.

Select drill file export; format=Excellon; units=mm.

Expected Result

A drill file (.drl) is created with all hole data.

5

Step 5: Name each Gerber file clearly according to the layer and project name, for example, board_top_copper.gbr.

File naming convention: [projectname]_[layer].gbr or .drl for drill file.

Expected Result

Files are named correctly for easy identification by manufacturing.

6

Step 6: Package all Gerber files and the drill file into a single compressed folder (zip).

Select all generated files and compress into board_gerbers.zip.

Expected Result

A single zip file containing all necessary files is ready to send.

7

Step 7: Review the Gerber files using a Gerber viewer to verify all layers are correct and aligned.

Open the zip in a Gerber viewer and check each layer visually.

Expected Result

No missing layers or misalignments; files are ready for manufacturing.

Final Result

Gerber Files Package
---------------------
| board_top_copper.gbr    |
| board_bottom_copper.gbr |
| board_top_soldermask.gbr|
| board_bottom_soldermask.gbr|
| board_top_silkscreen.gbr|
| board_bottom_silkscreen.gbr|
| board_outline.gbr       |
| board_drill.drl         |
---------------------
All files zipped as board_gerbers.zip

✓All necessary PCB layers are exported as Gerber files.

✓Drill file is included in Excellon format.

✓Files are named clearly for manufacturing.

✓Gerber files verified with viewer to ensure accuracy.

Bonus Challenge

Create a simple automated script or batch process to export Gerber files and drill files with correct settings and naming from your PCB design software.

Show Hint

Check if your PCB software supports scripting or command line export options to automate the Gerber generation process.

Practice

1. What is the primary purpose of generating Gerber files in PCB design?

easy

A. To provide manufacturing data for PCB fabrication

B. To simulate the electrical behavior of the circuit

C. To create a 3D model of the PCB

D. To write the software code for the PCB

Solution

1. Step 1: Understand Gerber file role

   Gerber files contain the detailed layer information needed by manufacturers to produce the PCB.

2. Step 2: Differentiate from other PCB tasks

   Simulation, 3D modeling, and coding are separate tasks not related to Gerber files.

3. Final Answer:

   To provide manufacturing data for PCB fabrication -> Option A

4. Quick Check:

   Gerber files = manufacturing data [OK]

Hint: Gerber files = manufacturing instructions for PCB layers [OK]

Common Mistakes:

• Confusing Gerber files with simulation files
• Thinking Gerber files are 3D models
• Assuming Gerber files contain software code

2. Which file format is commonly used for exporting Gerber files in PCB design software?

easy

A. .exe

B. .gbr

C. .docx

D. .jpg

Solution

1. Step 1: Identify standard Gerber file extension

   Gerber files typically use the .gbr extension to represent PCB layers.

2. Step 2: Exclude unrelated file types

   .exe is an executable, .docx is a document, and .jpg is an image, none used for Gerber export.

3. Final Answer:

   .gbr -> Option B

4. Quick Check:

   Gerber files use .gbr extension [OK]

Hint: Gerber files always end with .gbr extension [OK]

Common Mistakes:

• Choosing executable or document formats by mistake
• Confusing image files with Gerber files
• Using generic file extensions instead of .gbr

3. Given a PCB design with 4 layers, which of the following is the correct set of Gerber files to export?

medium

A. TopLayer.gbr, BottomLayer.gbr, Schematic.sch, DrillFile.drl

B. TopLayer.gbr, BottomLayer.gbr, DrillFile.drl, README.txt

C. TopLayer.gbr, BottomLayer.gbr, DrillFile.drl, Firmware.hex

D. TopLayer.gbr, BottomLayer.gbr, DrillFile.drl, SolderMaskTop.gbr

Solution

1. Step 1: Identify necessary Gerber files for 4-layer PCB

   Typical files include top and bottom copper layers, drill file for holes, and solder mask layers.

2. Step 2: Exclude unrelated files

   Schematic (.sch), firmware (.hex), and text files (.txt) are not part of Gerber exports.

3. Final Answer:

   TopLayer.gbr, BottomLayer.gbr, DrillFile.drl, SolderMaskTop.gbr -> Option D

4. Quick Check:

   Gerber export = copper + drill + mask files [OK]

Hint: Gerber exports include copper, drill, and mask files only [OK]

Common Mistakes:

• Including schematic or firmware files in Gerber export
• Missing drill or solder mask files
• Confusing file types for Gerber generation

4. You exported Gerber files but the manufacturer reports missing drill data. What is the most likely cause?

medium

A. The solder mask file is in the wrong format

B. The top copper layer file is corrupted

C. Drill file was not included in the export

D. The schematic file was not updated

Solution

1. Step 1: Understand the missing drill data issue

   Drill data is contained in a separate drill file (.drl) that must be exported explicitly.

2. Step 2: Identify the cause of missing drill data

   If the drill file is not included, the manufacturer cannot see hole locations, causing the issue.

3. Final Answer:

   Drill file was not included in the export -> Option C

4. Quick Check:

   Missing drill data = missing drill file export [OK]

Hint: Always include drill file when exporting Gerber files [OK]

Common Mistakes:

• Assuming copper or mask files cause drill issues
• Thinking schematic affects Gerber drill data
• Ignoring the need to export drill file separately

5. You have a multi-layer PCB design with inner layers and multiple solder mask layers. How should you prepare Gerber files to ensure correct manufacturing?

hard

A. Export each copper layer, solder mask layers, and drill file separately; verify with a Gerber viewer before sending

B. Export only the top and bottom copper layers and send the entire project folder

C. Export all layers combined into a single file to simplify manufacturing

D. Send the schematic and layout files directly to the manufacturer without exporting Gerbers

Solution

1. Step 1: Identify required Gerber files for multi-layer PCB

   Each copper layer, solder mask layer, and drill file must be exported separately to represent all PCB details.

2. Step 2: Verify files before manufacturing

   Using a Gerber viewer ensures files are correct and complete, preventing manufacturing errors.

3. Final Answer:

   Export each copper layer, solder mask layers, and drill file separately; verify with a Gerber viewer before sending -> Option A

4. Quick Check:

   Separate export + verification = correct Gerber preparation [OK]

Hint: Export all layers separately and verify with viewer before sending [OK]

Common Mistakes:

• Combining layers into one file causing confusion
• Sending schematic instead of Gerber files
• Skipping verification before manufacturing