Manufacturing Output

KiCad can generate all files required for PCB manufacturing and assembly, including Gerber files, drill files, pick-and-place data, and bill of materials. The export system ensures your design can be accurately reproduced by fabrication houses.

Overview

Manufacturing output is handled by various exporter classes in KiCad. The most important are Gerber generation (source/pcbnew/exporters/gerber_jobfile_writer.h), drill file generation, and assembly file creation.

Gerber Files

What are Gerber Files?

Gerber files are the industry standard format for PCB manufacturing. Each file represents one layer of the PCB:

Copper Layers

Front, back, and internal copper patterns

Solder Mask

Protective coating over copper

Silkscreen

Component designators and markings

Paste Stencil

Solder paste application pattern

Generating Gerber Files

Open Plot Dialog

In Pcbnew: File → Fabrication Outputs → Gerbers (.gbr)

Select Layers

Choose which layers to export:Standard 2-layer board:

F.Cu (front copper)
B.Cu (back copper)
F.SilkS (front silkscreen)
B.SilkS (back silkscreen)
F.Mask (front solder mask)
B.Mask (back solder mask)
F.Paste (front solder paste, SMD only)
B.Paste (back solder paste, SMD only)
Edge.Cuts (board outline)

Multi-layer board: Add all internal copper layers (In1.Cu, In2.Cu, etc.)

Configure Options

Set Gerber parameters:

// Plot format: Gerber (RS-274X)
bool plotBorderAndTitle = false;      // Exclude title block
bool plotFootprintValues = true;      // Include component values  
bool plotFootprintReferences = true;  // Include reference designators
bool plotInvisibleText = false;       // Exclude hidden text
bool subtractMaskFromSilk = true;     // Clip silkscreen from pads

Coordinate format: 4.6 (millimeters) or 4.5 (recommended)Aperture macros: Use for complex pad shapes

Generate Files

Click Plot to create Gerber files.Output files:

project-F_Cu.gbr
project-B_Cu.gbr  
project-F_SilkS.gbr
project-B_SilkS.gbr
project-F_Mask.gbr
project-B_Mask.gbr
project-Edge_Cuts.gbr

Generate Gerber Job File

Create a Gerber job file (JSON format) describing the fabrication:

// Source: pcbnew/exporters/gerber_jobfile_writer.h:71
class GERBER_JOBFILE_WRITER
{
    bool CreateJobFile( const wxString& aFullFilename );
};

The job file includes:

List of Gerber files and their layer assignments
Board dimensions
Layer stackup (copper/dielectric thickness)
Material specifications
Manufacturing notes

Gerber File Structure

Gerber files use RS-274X format:

G04 KiCad Gerber File*
G04 Created by Pcbnew*
%FSLAX46Y46*%
%MOMM*%
%TF.FileFunction,Copper,L1,Top*%
%TF.FilePolarity,Positive*%
%ADD10C,0.200000*%
D10*
X100000Y100000D03*
M02*

Drill Files

NC Drill Files

Generate drill files for through-holes and vias:

Open Drill File Dialog

File → Fabrication Outputs → Drill Files (.drl)

Select Format

Choose drill file format:

Excellon
Gerber X2

Most common format (NC Drill)

// Source: pcbnew/exporters/gendrill_excellon_writer.h
class EXCELLON_WRITER : public GENDRILL_WRITER_BASE
{
    void CreateDrillandMapFilesSet( const wxString& aPlotDirectory,
                                   bool aGenDrill, bool aGenMap );
};

Settings:

Units: Millimeters (recommended) or inches
Zeros: Decimal format (3.3) or suppress leading/trailing
Precision: 3:3 (mm) or 2:4 (inch)

Modern drill format using Gerber

// Source: pcbnew/exporters/gendrill_gerber_writer.h
class GERBER_DRILL_WRITER : public GENDRILL_WRITER_BASE
{
    // Creates drill data as Gerber file
};

Advantages:

Includes tool information
Better integration with Gerber workflow
Supports advanced attributes

Configure Drill Options

Set drill parameters:

PTH and NPTH in single file: Combine all holes
Separate files: PTH drills separate from NPTH
Merge PTH and NPTH: All holes together (not recommended)
Drill origin: Absolute or auxiliary axis

Generate Drill Map

Create visual drill map (PDF or Gerber) for reference.Shows:

Drill hole positions
Tool numbers and sizes
Layer information

Generate Files

Output files:

project-PTH.drl         # Plated through-holes
project-NPTH.drl        # Non-plated holes  
project-PTH-drl_map.pdf # Drill map

Drill File Structure

Excellon format example:

M48
; DRILL file {KiCad 8.0} date 2024-01-15
; FORMAT={-:-/ absolute / metric / decimal}
FMAT,2
METRIC
T1C0.300
T2C0.800
T3C1.000
%
G90
G05
T1
X100.0Y100.0
X120.0Y100.0
T2
X100.0Y150.0
M30

Assembly Files

Pick-and-Place (PnP)

Generate component position files for automated assembly:

Export Position File

File → Fabrication Outputs → Component Placement (.pos)

Select Format

Choose file format:

ASCII (CSV): Human-readable, most compatible
Gerber X3: Modern format with full metadata

Configure Options

Set position file parameters:

// Units: mm or inches
// Format: CSV (comma-separated values)
// Include columns:
// - Reference (R1, C1, U1)
// - Value (10k, 100nF, STM32)
// - Package (0805, SOIC-8)
// - X, Y position
// - Rotation (degrees)
// - Layer (top/bottom)

Filter Components

Options:

Include only SMD: Exclude through-hole parts
Include only with SMD attribute: Use footprint attributes
Exclude from pos files: Honor footprint flag
Exclude DNP: Skip Do Not Populate components

PnP File Format

CSV format example:

Ref,Val,Package,PosX,PosY,Rot,Side
R1,10k,R_0805_2012Metric,25.4,50.8,0,top
C1,100nF,C_0805_2012Metric,30.5,50.8,90,top  
U1,STM32F103,LQFP-48_7x7mm_P0.5mm,50.0,75.0,0,top

Gerber X3 Pick-and-Place

Modern format with component metadata:

%TF.FileFunction,Component,Pick&Place,Top*%
%TF.GenerationSoftware,KiCad,Pcbnew,8.0*%
%TO.C,R1*%
%TO.CRot,0.000*%
%TO.CVal,10k*%
%TO.CPkg,R_0805_2012Metric*%
X25400000Y50800000D03*
%TD*%

Bill of Materials (BOM)

Generate BOM from Schematic

In Eeschema: Tools → Generate BOM

Built-in BOM
BOM Plugins

Simple component list:

Grouped by value
Shows reference designators
Includes quantities
Basic CSV or XML output

Advanced BOM generation using Python/XSLT scripts:

# Example BOM plugin
# Input: XML netlist
# Output: Custom formatted BOM

import xml.etree.ElementTree as ET
import csv

# Parse netlist
tree = ET.parse('netlist.xml')
components = tree.findall('.//comp')

# Group by value and footprint
bom = {}
for comp in components:
    value = comp.find('value').text
    footprint = comp.find('footprint').text  
    ref = comp.attrib['ref']
    
    key = (value, footprint)
    if key not in bom:
        bom[key] = []
    bom[key].append(ref)

# Output CSV
with open('bom.csv', 'w') as f:
    writer = csv.writer(f)
    writer.writerow(['Qty', 'Value', 'Footprint', 'References'])
    for (value, footprint), refs in bom.items():
        writer.writerow([len(refs), value, footprint, ','.join(refs)])

BOM Content

Typical BOM includes:

string

required

Component designator (R1, C5, U3)

number

required

Number of identical components

string

required

Component value or part number

string

PCB package type

string

Link to component datasheet

string

Component manufacturer

string

Manufacturer part number

string

Where to purchase (Digi-Key, Mouser, etc.)

string

Supplier part number

Other Export Formats

IPC-2581

Modern PCB fabrication format:

// Source: pcbnew/pcb_io/ipc2581/
// Complete design transfer including:
// - Stackup definition
// - Board outline
// - Component placement  
// - Netlist
// - BOM

GenCAD

Legacy CAM format:

// Source: pcbnew/exporters/export_gencad.cpp
void Export_GenCAD( const wxString& aFullFileName, BOARD* aBoard );

Hyperlynx

Signal integrity simulation:

// Source: pcbnew/exporters/export_hyperlynx.cpp
// Exports for SI/PI analysis tools

IDF (Intermediate Data Format)

Mechanical CAD integration:

// Source: pcbnew/exporters/export_idf.cpp  
// Board outline and component heights for MCAD

Fabrication Package

Typical fabrication package includes:

fabrication/
├── gerbers/
│   ├── project-F_Cu.gbr
│   ├── project-B_Cu.gbr
│   ├── project-F_SilkS.gbr
│   ├── project-B_SilkS.gbr
│   ├── project-F_Mask.gbr
│   ├── project-B_Mask.gbr
│   ├── project-Edge_Cuts.gbr
│   └── project-job.gbrjob
├── drill/
│   ├── project-PTH.drl
│   ├── project-NPTH.drl
│   └── project-drl_map.pdf
├── assembly/
│   ├── project-top-pos.csv
│   ├── project-bottom-pos.csv
│   ├── bom.csv
│   └── assembly_drawing.pdf
└── mechanical/
    ├── project.step
    └── board_outline.dxf

Zip all files together and send to your PCB manufacturer. Most accept Gerber + Excellon drill files.

Manufacturing Notes

Include fabrication notes with your order:

Board Specifications

Material: FR4, aluminum, flexible, etc.
Thickness: 1.6mm (standard), 0.8mm, 2.0mm, etc.
Copper weight: 1oz (35µm), 2oz, etc.
Layers: 2, 4, 6, 8, etc.
Finish: HASL, ENIG, OSP, etc.
Color: Green, blue, red, black, white mask
Min trace/space: Based on design rules
Min drill: Smallest hole size used

Special Requirements

Controlled impedance traces
Blind/buried vias
Edge plating
Chamfered edges
Gold fingers (edge connectors)
Specific markings or serialization

Validation Before Manufacturing

Run DRC

Ensure all design rule violations are resolved.

Verify Gerbers

Use Gerber viewer (GerbView in KiCad) to inspect all layers:

Check copper patterns
Verify silkscreen placement
Confirm solder mask openings
Inspect board outline

Check Drill Files

Review drill map:

Verify hole sizes
Check PTH vs NPTH
Confirm via locations

Review Assembly Data

Validate pick-and-place:

Component positions correct
Rotations accurate
No missing components
DNP flags set properly

3D Check

Use 3D viewer to verify:

Component heights
Mechanical clearances
Connector orientations
Mounting hole positions

Best Practices

Use Standard Formats

Stick to Gerber RS-274X and Excellon drill files for maximum compatibility with manufacturers.

Include Job File

Always generate a Gerber job file. It helps manufacturers understand your design intent.

Check with Manufacturer

Verify your manufacturer’s requirements before generating files. Some have specific layer naming or format preferences.

Archive Everything

Keep complete fabrication packages with design files. Include date and revision in filenames.

Test First Article

Order a small quantity initially to verify the design before full production.

Source Code References

// Gerber job file generation
// Location: source/pcbnew/exporters/gerber_jobfile_writer.h:71  
class GERBER_JOBFILE_WRITER

// Excellon drill file generation
// Location: source/pcbnew/exporters/gendrill_excellon_writer.h
class EXCELLON_WRITER

// Gerber X2 drill files
// Location: source/pcbnew/exporters/gendrill_gerber_writer.h  
class GERBER_DRILL_WRITER

Next Steps

Design Rules

Configure constraints for manufacturability

PCB Layout

Design boards for manufacturing

3D Models

Export 3D for mechanical integration

Getting Started

Core Applications

Design Workflow

Advanced Features

Manufacturing Output

Overview

Gerber Files

What are Gerber Files?

Copper Layers

Solder Mask

Silkscreen

Paste Stencil

Generating Gerber Files

Gerber File Structure

Drill Files

NC Drill Files

Drill File Structure

Assembly Files

Pick-and-Place (PnP)

PnP File Format

Gerber X3 Pick-and-Place

Bill of Materials (BOM)

Generate BOM from Schematic

BOM Content

Other Export Formats

IPC-2581

GenCAD

Hyperlynx

IDF (Intermediate Data Format)

Fabrication Package

Manufacturing Notes

Board Specifications

Special Requirements

Validation Before Manufacturing

Best Practices

Source Code References

Next Steps

Design Rules

PCB Layout

3D Models

​Overview

​Gerber Files

​What are Gerber Files?

Copper Layers

Solder Mask

Silkscreen

Paste Stencil

​Generating Gerber Files

​Gerber File Structure

​Drill Files

​NC Drill Files

​Drill File Structure

​Assembly Files

​Pick-and-Place (PnP)

​PnP File Format

​Gerber X3 Pick-and-Place

​Bill of Materials (BOM)

​Generate BOM from Schematic

​BOM Content

​Other Export Formats

​IPC-2581

​GenCAD

​Hyperlynx

​IDF (Intermediate Data Format)

​Fabrication Package

​Manufacturing Notes

​Board Specifications

​Special Requirements

​Validation Before Manufacturing

​Best Practices

​Source Code References

​Next Steps

Design Rules

PCB Layout

3D Models

Overview

Gerber Files

What are Gerber Files?

Generating Gerber Files

Gerber File Structure

Drill Files

NC Drill Files

Drill File Structure

Assembly Files

Pick-and-Place (PnP)

PnP File Format

Gerber X3 Pick-and-Place

Bill of Materials (BOM)

Generate BOM from Schematic

BOM Content

Other Export Formats

IPC-2581

GenCAD

Hyperlynx

IDF (Intermediate Data Format)

Fabrication Package

Manufacturing Notes

Board Specifications

Special Requirements

Validation Before Manufacturing

Best Practices

Source Code References

Next Steps