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
