Product category:
PCB Assembly Equipment and Tools
News Release from: Rofin-Baasel UK | Subject: Laser barcoding
Edited by the Electronicstalk Editorial
Team on 29 November 2005
Lasers hit the mark for traceability
Laser marked barcodes offer many advantages over adhesive labels in electronics manufacturing.
The ability to track a circuit board assembly throughout its manufacturing, sales and service cycles is of the utmost importance Many companies require that each circuit board be marked with a unique barcode identifier that can later be read by equipment that is part of an automated assembly line
This article was originally published on Electronicstalk on 8 Nov 2004 at 8.00am (UK)
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The traceability of circuit boards is usually done by assigning a unique serial number to each board in the form of a barcode.
The two most common methods of applying a serialised barcode message to a circuit board are through the application of labels via laser marking.
Although barcode labels offer a cost-effective solution where small production volumes of boards are involved, higher production cycles benefit from laser marking.
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Laser marked barcodes are permanent.
The manufacturer no longer needs to worry about labels falling off and not knowing what serial number of a board is when it is returned for repair.
Laser marked codes are high in quality, also eliminating the worry of misaligned labels.
Laser barcoding allows each board to be uniquely identified online, with very little, if any, operator intervention.
There are two approaches that can be taken to laser mark a printed circuit board.
The first approach requires the laser to selectively remove the ink from the circuit board to form the dark bars of the code.
The dark bars are the colour of the underlying circuit board, the light bars are the colour of the ink patch.
In the majority of cases a white ink is used to provide the highest contrast between the light and dark bars of the code.
To remove the ink from the board a Nd:YAG laser is used.
This laser can also be used to mark such items as heatsinks, fans or other components that may be on the board.
Many companies find this useful to ensure that original components are returned for repair and to reduce the risk of counterfeiting.
With the second approach the laser does not remove the ink from the board, but instead changes the colour of the ink through a photoreactive process to produce the dark bars.
The light bars again are the colour of the ink patch.
A CO2 or Nd:YAG laser can be used in this application; however the CO2 laser does not offer as much flexibility as the Nd:YAG with its ability to mark other components on the board.
This approach does offer the advantage that the marking can take place on ink patches applied over copper traces on the boards with no risk of damage to the circuitry.
Both these approaches are widely used in the electronics industry, and the majority of companies will request that the laser is integrated into their existing assembly lines.
Rofin-Baasel can provide turnkey packages to meet this need. Request a free brochure from Rofin-Baasel UK ...
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