Understanding PCB Legends: Purpose, Placement, and Benefits

A PCB legend is a layer of text placed on a printed circuit board (PCB) to label components and provide other useful information. Sometimes called silkscreen or component identification, legend text is printed on top of the circuit board’s solder mask as one of the last steps in the circuit board manufacturing process.

Though a PCB may not technically require a legend to function, this text provides information that’s vital for assembly, testing and troubleshooting by the end user. Some common pieces of information included in a PCB legend include:

• Reference indicators labeling component types
• Polarity indicators labeling the polarity of certain components
• Component outlines indicating where components should go
• Test points to assist with testing and troubleshooting
• Manufacturer information, serial numbers and other labeling

By indicating proper orientation and placement of components and providing other information about the circuit board, a legend helps ensure that parts are assembled correctly and continue to function when they reach consumers. As a result, you should always plan to include a legend on your circuit boards. It should feature a clear font in white or black ink, and any text you include on your circuit board should follow the manufacturer’s guidelines for clearance so that every part of the legend is visible.

Contact Millennium Circuits Limited, Your PCB Supplier

Whether you’re finalizing the details of your PCB design or just getting started, you need to find a PCB supplier that can deliver affordable, high-quality circuit boards. At Millennium Circuits Limited, we can supply PCBs that meet your specifications, whether you have a high- or low-volume request. Contact us today to learn more about our capabilities.