Background Theory > Part Design > What is a PCB silkscreen?

A PCB silkscreen is a layer of markings that is printed on the surface of a printed circuit board (PCB). The silkscreen layer contains text, symbols, and other graphical information that is used to identify and label the components, test points, and other features on the board.

The silkscreen layer is typically printed in white ink on top of the solder mask layer, which is the layer that covers most of the copper traces and pads on the board. The silkscreen layer is used to provide information about the board's components, such as the part numbers, values, and reference designators. It may also include other information such as logos, warnings, and instructions.

Some common silkscreen markings include:

Reference designators: These are letters and numbers that are used to identify the components on the board. For example, "R1" might indicate a resistor, while "C2" might indicate a capacitor.

Part numbers: These are the manufacturer's part numbers for the components on the board.

Test points: These are locations on the board where test equipment can be attached to measure voltages or currents.

Board name and revision: This identifies the name and revision number of the board.

Other markings: These may include logos, warning symbols, and other instructions or notes.

The silkscreen layer is an important part of the PCB design, as it helps to ensure that the board can be assembled and tested correctly. By providing clear and accurate information about the components and other features on the board, the silkscreen layer can help to prevent errors and ensure that the board functions as intended.