Printed Circuit Board Assembly & PCB Design SMT Electronics Assembly Manufacturing Forum

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


marking of pcb's

pzohbon

#5480

laser or ink jet marking of pcb's | 6 March, 2001

I am looking at putting a laser or ink jet marking system for barcoding of pcb's in our smt production area. As and inline system it will need the capability to handle different size boards.

We use dark green pcb's except for couple red and blues mixed in, so contrast might be a problem. I'm also concerned about maintenance and servicing issues.

I would appreciate any comments. Thanks

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Cosine Theta

#5484

laser or ink jet marking of pcb's | 7 March, 2001

Barcode needs a light colour backgroup so that the scanner can read. No way you can mark on the solder mask and become readable. I found most of the time the investment cannot be paid back within 5 years. Most of the time it is product requirement that drives the need for laser/inkjet. Labels still have the best flexibility and reliability.

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#5491

laser or ink jet marking of pcb's | 7 March, 2001

I agree. The bar coded label you use should not be affected by the solder mask of the board. The label should have sharp contrast between the segments of the code to modulate the returned light and allow the reader to discriminate between light and dark areas and the size of those areas. ANSI X3.182 Guideline For Bar Code Print Quality Print defines bar code print quality requirements. It�s available from Automatic Identification Manufacturers.

The ability of current technology inkjet printers to print acceptable quality labels is dependent on the surface of the label.

I submitted a review of "The Bar Code Book: Reading, Printing, Specification, and Application" by Robert Palmer [http://casi.simplenet.com/j/music/a/addicted.mid ] [No, no, no!!! Not that one.] [After that, don�t you get an image of a bunch of yente sitting around the party room at Don Goodman�s Towering Palms Retirement Home in Palm Beach? Or may be over at Frederick "Freddie" Capuano�s Green Grove Retirement Home in Verona, New Jersey across from the Verona Park?] for inclusion in the SMTnet Newsletter. It�s an excellent reference for anyone with hands-on responsibility for bar coding.

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blnorman

#5497

laser or ink jet marking of pcb's | 8 March, 2001

We've been using pre-printed labels on our PCB's for years, with 8 - 10 hours a week down time associated with them. Last October we put a CO2 laser marker on one of our lines. In 6 months we've had a total of 30 minutes down time.

We use a 2D barcode and our circuit board supplier puts down a silk screen on the board that we lase the code into. The silk screed adds about five cents per board, but the virtual elimination of down-time attributed to labelling is worth it. Most laser marker manufacturers will take samples of your boards, mark them to your specifications, then give you an evaluation of the mark. I personally sent material samples to 3 companies for their evaluation.

The inline marker cost about $30,000 more than the label applicator, but no label material cost. The CO2 tube has to be "recharged" every 2 years. The X-Y positioning system allows us to mark any size board. From the preliminary indications, all lines will go to laser marking with 2D codes when we change to a new product.

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