The Gerber Format Specification A format developed by Ucamco Revision 2016.01 Table of Contents Preface ......................................................................................................................... 8 1 Introduction ............................................................................................................ 9 1.1 About this document .......................................................................................... 9 Scope and Target Audience ........................................................................ 9 Questions and Feedback ............................................................................ 9 References ................................................................................................. 9 1.2 Copyright and Intellectual Property .................................................................. 10 1.3 History of the Gerber File Format .................................................................... 11 Standard Gerber ....................................................................................... 11 Extended Gerber....................................................................................... 11 The Great Reform ..................................................................................... 11 The Second Extension .............................................................................. 12 Standard Gerber Revoked ........................................................................ 12 Further Clarification ................................................................................... 12 1.4 Record of Revisions ........................................................................................ 13 Revision 2016.01 ...................................................................................... 13 Revision 2015.10 ...................................................................................... 13 Revision 2015.07 ...................................................................................... 13 Revision 2015.06 ...................................................................................... 13 Revision J4 ............................................................................................... 14 Revision J3 ............................................................................................... 14 Revision J2 ............................................................................................... 14 Revision J1 ............................................................................................... 14 Revision I4 ................................................................................................ 14 Revision I3 .............................................................................................. 14 Revision I2 .............................................................................................. 14 Revision I1 .............................................................................................. 14 1.5 About Ucamco ................................................................................................. 16 2 Overview of the Gerber Format ........................................................................... 17 2.1 File Structure ................................................................................................... 17 2.2 Processing Gerber File .................................................................................... 18 2.3 Graphics Objects ............................................................................................. 20 2.4 Apertures ......................................................................................................... 21 2.5 Draw and Arc Objects ...................................................................................... 22 2.6 Contours .......................................................................................................... 23 2.7 Operation Codes ............................................................................................. 24 2.8 Graphics State ................................................................................................. 25 Copyright Ucamco NV ii Having a question or remark about the spec? Please contact us at [email protected] 2.9 Dark and Clear Polarity ................................................................................... 28 2.10 Attributes ....................................................................................................... 29 2.11 Processing Gerber File with Attributes .......................................................... 30 2.12 Conformance ................................................................................................ 32 2.13 Example Files ............................................................................................... 33 Example: Two Square Boxes .................................................................. 33 Example: Use of Levels and Various Apertures ...................................... 34 Example: A Drill File ................................................................................ 38 2.14 Glossary ........................................................................................................ 41 3 Syntax ................................................................................................................... 45 3.1 Conventions for Syntax Rules.......................................................................... 45 3.2 File Extension, MIME Type and UTI ................................................................ 46 3.3 Character Set .................................................................................................. 47 3.4 Data Blocks ..................................................................................................... 48 3.5 Commands ...................................................................................................... 49 Commands Overview ................................................................................ 49 Function Code Commands ....................................................................... 51 Extended Code Commands ...................................................................... 52 3.6 Data Types ...................................................................................................... 54 Integers ..................................................................................................... 54 Decimals ................................................................................................... 54 Coordinate Number ................................................................................... 54 Hexadecimal Number................................................................................ 54 Names ...................................................................................................... 54 Strings ...................................................................................................... 54 4 Graphics ............................................................................................................... 56 4.1 Graphics Overview .......................................................................................... 56 4.2 Operations (D01/D02/D03) .............................................................................. 59 Coordinate Data Syntax ............................................................................ 60 D01 Command .......................................................................................... 61 D02 Command .......................................................................................... 62 D03 Command .......................................................................................... 62 Example .................................................................................................... 63 4.3 Current Aperture (Dnn) .................................................................................... 64 4.4 Linear Interpolation Mode (G01) ...................................................................... 65 G01 Command ......................................................................................... 65 D01 Command .......................................................................................... 65 4.5 Circular Interpolation (G02/G03) and Quadrant Modes (G74/G75) .................. 66 Circular Arc Overview ............................................................................... 66 Circular Arc Definition ............................................................................... 67 G02 Command ......................................................................................... 68 Copyright Ucamco NV iii Having a question or remark about the spec? Please contact us at [email protected] G03 Command ......................................................................................... 68 G74 Command ......................................................................................... 68 G75 Command ......................................................................................... 69 D01 Command .......................................................................................... 69 Example: Single Quadrant Mode .............................................................. 71 Example: Multi Quadrant Mode ................................................................. 72 Numerical Instability in Multi