Gerber files are vector format files used for PCB design, transferring design data from CAD software to PCB manufacturing equipment. Gerber files contain information about various layers and aspects of PCB design, with different file types corresponding to different design elements. In PCB manufacturing, they are also known as photoplot files. Understanding the types and extensions of Gerber files generated by different PCB design software ensures the proper transfer of design files to the manufacturing stage.

The Gerber file is a standard format defined by the EIA and is divided into RS274-D and RS274-X. RS274-X is an extended version of RS274-D. Whenever possible, the production and manufacturing departments should request the user or design department to provide RS274-X Gerber files, as this format is more conducive to the preparation of each manufacturing process.

Below is a chart summarizing the main contents of Gerber files:

Next, we will introduce the types and extensions of Gerber files generated by several commonly used PCB software. (Examples are based on a 2-layer board.)

Kicad

F_Cu.gbr: Top copper layer

B_Cu.gbr: Bottom copper layer

F_Silkscreen.gbr: Top silkscreen layer

B_Silkscreen.gbr: Bottom silkscreen layer

F_Mask.gbr: Top soldermask layer

B_Mask.gbr: Bottom soldermask layer

F_Paste.gbr: Top pastemask layer

B_Paste.gbr: Bottom pastemask layer

Edge_Cuts.gbr: Board outline layer

NPTH.drl: Non-plated drill file

PTH.drl: Plated drill file

Eagle

gtl: Top copper layer

gbl: Bottom copper layer

gto: Top silkscreen layer

gbo: Bottom silkscreen layer

gts: Top soldermask layer

gbs: Bottom soldermask layer

gtp: Top pastemask layer

gbp: Bottom pastemask layer

gko/gm: Board outline layer

drl/txt: Drill file

Cadence Allegro

TOP.art: Top copper layer

BOTTOM.art: Bottom copper layer

SILK_TOP.art: Top silkscreen layer

SILK_BOTTOM.art: Bottom silkscreen layer

SOLEDER_TOP.art: Top soldermask layer

SOLEDER_BOTTOM.art: Bottom soldermask layer

PASTE_TOP.art: Top pastemask layer

PASTE_BOTTOM.art: Bottom pastemask layer

OUTLINE.art: Board outline layer

DRILL.art: Drill file

.rou: slot hole drill file (If elliptical or rectangular holes are required on the PCB）

art_param.txt: Aperture parameter text file

nc_param.txt: Numerical Control (NC) drilling parameter text file

Altium Designer

.GTL: Top copper layer

.GBL: Bottom copper layer

.GTO: Top silkscreen layer

.GBO: Bottom silkscreen layer

.GTS: Top soldermask layer

.GBS: Bottom soldermask layer

.GTP: Top pastemask layer

.GBP: Bottom pastemask layer

.GM/.GKO: Board outline layer

.TXT: Drill file