Laser marking for board identification

Paul Boughton

Marking of PCBs and modules for traceability and warranty purposes is often a costly and time consuming activity, adding little or no value to the end product.

With reducing circuit size and increasing customer demands, the traditional method of applying self-adhesive labels is becoming less suitable for many applications.

Laser Marking of PCBs and substrates is now becoming a popular method of providing permanent identification. Laser marking provides safe repeatable reliable markings without maintenance and on-going consumable costs.

For PCBs, a CO2 laser is typically used to etch a mark into Solder Resist or Legend boxes, while Nd: YAG Lasers are used when marking metals, plastics and ceramics. Both methods are currently used with a variety of barcodes; Human readable, 1D and 2D, with 2D becoming more popular for higher density pcbs. Decisions regarding matrix size will depend upon data requirements, but also the quality of scanners used for downstream verification.

In-Line Laser Marking Cells offering suitable verification scanners and interface software may be networked to give the advantage of data controlled production and remote programming. For smaller manufacturing companies, Bare Board identification is becoming a Stores ‘kitting’ function; issuing Laser Marked boards to multiple production lines.

NUTEK (UK) Limited is based in Colchester, Essex, UK.