Introduction

What is a Gerber file?

A Gerber file (also known as artwork) is a 2-D graphical representation of a single layer of a PCB. A typical design will have individual Gerber files for each layer (e.g., top copper, bottom copper, top silkscreen, bottom silkscreen, top soldermask, bottom soldermask) of a PCB.

What is a drill file?

A drill file (also known as a NC Drill file) stores both the specific sizes and types of drill bits that will be used in manufacturing a PCB in addition to the specific coordinate locations where each hole must be drilled. Our equipment uses files that are in Excellon format.

You need both Gerber files for each layer and a single drill file in order to successfully submit your design for manufacturing.

Steps:

1. Open your project in the KiCad PCB Editor

2. Click “File > Plot” (see Figure 1).

Figure 1

3. The Plot window will pop up. Then, click “ ” to choose the directory of the folder contains your project. Inside your project folder, create a new folder called “Gerber”. Then, select “Gerber” (see Figure 2).

Figure 2

4. After selecting the “Gerber”, the Output director should show “Gerber\”. Go to “Include Layers”, select “F.Cu” (Front/Top Layer), “B.Cu” (Bottom Layer), “F.Silkscreen” (Silkscreen of Front/Top Layer), “B.Silkscreen” (Silkscreen of Bottom Layer), “F.Mask” (Soldermask of Front/Top Layer), “B.Mask” (Soldermask of Bottom Layer), “Edge.Cuts” (Board Outline). Set the “General Options” and “Gerber Options” as Figure 3. Then, click “Plot”. Before closing the window, click “Generate Drill Files…”.

Figure 3

Note:

a. Silkscreen is a layer of ink traces used to identify components, test points, parts of the PCB, warning symbols, logos and marks etc.

b. Soldermask is a thin layer of polymer that is put on a circuit board to protect the copper from oxidation and shorts during operation. It also protects the PCB from environmental influences such as dust and several other contaminants that may lead to shorts in the long run.

5. Set the “Generate Drill Files” as Figure 4. Then, click “Generate Drill File”. You will see the drill files are saved in your “Gerber” folder.

Figure 4

6. In your “Gerber” folder, you should have 10 files in total (see Figure 5).

Figure 5

Note

1. NPTH (Non-Plating Through Hole) refers to a hole without copper in the borehole wall. It is generally used as the positioning hole and screw hole of PCB. The hole diameter is usually larger than PTH.

2. PTH (Plating Through Hole), the borehole wall has a layer of copper, the PTH holes on PCB has two purposes:

   • Used as component hole for welding DIP components, the hole diameter must be larger than the pin of the component, so that the component can be inserted in the PTH.
   • Another relatively small PTH (Plating Through Hole), also known as “Via”, can be used to connect and conduct wiring between different layers in PCB.