Laser Marking of ECC 200 2-d Matrix Codes o-n Printed Circuit Boards - 0 views
started by Fitzgerald Robbins on 16 Sep 13
started by Fitzgerald Robbins on 16 Sep 13
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The 2-d matrix rule provides a way to store alphanumeric character strings in very small regions of the printed circuit board. Laser observing technology provides a way of completely applying 2D matrix limitations to many board substrates. The high-accuracy and high-resolution of beam-steered laser marking systems provides the way to create well-defined, large consistency limitations no matter code size. Laser marking also offers the individual having a computer-controlled marking process for easy implementation into computerized product tracking systems.
ECC 200 2-d Matrix Codes
Two-dimensional symbologies encode information in-the kind of a checkerboard pattern of on/off cells. Certain benefits of Data Matrix requirements over old-fashioned 1D barcodes include:
Encode information electronically, in the place of the development of data in conventional barcodes. Ems Electronics Manufacturing contains further about the meaning behind it.
Can provide low-contrast printing on areas without requiring a name
Provide very high information density - the best among other popular 2-d codes, which means that you are able to place a great deal of information in a very small area.
They're scaleable, meaning you can produce them and study them in various degrees of magnification - only limited by the quality of the available printing and imaging practices.
Due to the high data density natural to Data Matrix rules, they also offer integrated error-correction techniques which allow completely recovering the message encoded in a Data Matrix symbol even if the tag is damaged and missing as much as 20% of the symbol.
They're read by video cameras instead of a scanned laser employed for reading mainstream barcodes, meaning they can be read in just about any orientation.
ECC 200 Data Matrix is the most popular 2-D symbology with extensive use within automotive, aerospace, electronics, semiconductor, medical products and other production unit-level traceability applications. Where conventional barcodes were too large Information Matrix codes are typically not replacing mainstream linear barcodes, but are being used, did not provide adequate storage capacity, or were unreadable.
Information Matrix Code Framework
The 2D matrix codes appear as-a 'checkerboard' using the individual squares (cells) in either on on (white) or off (black) state. The code consists of four distinct components.
The Finder 'R' Pattern consists of a great line of cells along the left side and bottom of the code that orients the reader to the design of the 2D code.
The Clock Track is a collection of on/off cells along the right edge and top of the code that designates the row/column count to the reader.
The Data Region is the pattern of black and white cells within the M pattern and the time paths that have the content of the signal.
The Quiet Zone around the rule must be free from any characteristics that could be apparent to the reader. The quiet area should be at the very least two rows/columns broad for limitations made of square cells. The quiet zone ought to be at the very least four rows/columns large for codes made out of round cells (dots).
ECC 200 Data Matrix codes can keep as much as 3,116 numeric, 2,335 alphanumeric characters or 1,555 bytes of binary information in a 144 order by 144 row selection. More practical symbol measurements for printed circuit boards may still include a significant amount of data.
Laser Observing Program
The laser marking system contains the optics, the laser source, and the system.
The laser is just a light amplifier generating a brilliant, collimated beam of light at a particular wavelength. For FR4 and solder mask applications, many people choose the air-cooled CO2 laser operating at the 10,640nm far-infrared wavelength. This laser produces exemplary observing results, and provides a few performance and cost benefits.
The laser is projected through two beam-deflecting mirrors mounted to high-speed, high-accuracy galvanometers. As the mirrors are turned under direction of the system computer, the laser beam scans across the target marking surface to 'bring' the required marking picture.
After the laser beam is deflected from your mirrors, it's focused for the smallest spot possible by flat-field focusing optics. The flat-field focusing assembly can be a multi-element optical device designed to keep the focal plane of the focused laser over a relatively flat plane through the observing industry. The focused laser light related marking power and significantly advances the power density.
The function of the laser optical train would be to focus the laser beam into a little place and to scan the laser beam over the target surface with high speed and accuracy. With-the CO2 laser setup, the focused spot size and associated marking line width is about 0.0035' to 0.004.' Man-readable text figures can be as small as 0.040' and 2D matrix limitations can be made out of individual features as small as just one 0.004' dot.
PCB Noticing
The heat generated by the laser beam thermally changes the outer lining of the table to create a contrasting, readable mark, to mark printed circuit boards. The process doesn't require labels, stencils, blows or some other additional hardware or consumable.
For printed circuit board applications, a few different versions of the method can be used for different board/coating materials and background conditions.
Solder mask or other Conformal Coatings on FR4 Boards -
The laser beam can modify the consistency of the coating, giving a lighter different appear-ance to it, or can completely take away the coating to reveal the underlying substrate or copper ground plane.
Uncoated FR4 -
The laser beam changes the surface of the surface of the FR4 creating a near white appearance.
Silk-screened Ink Block -
For customers who already silkscreen portion identification or other fixed informative data on the boards, a silk-screened white ink block can work as a background to the 2D matrix signal to-optimize readability. This system is very valuable when
E The background color of the board resembles the color of the laser mark.
E Underlying circuitry would obscure the picture to code readers.
o The board material isn't suitable for laser marking, including ceramic substrates.
2-d Matrix Code Evidence
Proof of the content and legibility of the 2D matrix codes is an important step in the general quality plan. After marking of every world, the reader verifies the integrity of the level before indexing the laser marking head to the following marking place. The audience retrieves the alpha-numeric text string in the 2-d code and compares it with the text string which was to be noted.
The audience also assesses the legibility of the code based on many different parameters including foreground/background comparison, geometric accuracy (skew, squareness, etc.) and the dimensional accuracy of both the marked and unmarked cells. If you are concerned by the Internet, you will possibly hate to learn about electronics contract manufacturers. The 2D matrix rules are then grouped as passed (green), warned (yellow) or unsuccessful (red). For over all manufacturing efficiency, the laser system could be set to examine only a select few 2D codes on a screen, then to automatically switch to confirming every code when the code legibility drops below a given amount.
Today's viewers do a superb work reading lower comparison 2-d rules. If the laser marking system is installed on an assembly line with older 2D matrix readers downstream from the laser gun, the confirmation reader may be designed to evaluate the codes based on the performance of the older downstream readers in order to guarantee consistent performance through the entire assembly process.
Noticing Performance
The typical printed circuit board sign is a fully-automated, SMEMA-compliant, through-conveyor laser marking system. The overall efficiency of the laser sign is comprised of a few measures which make up the period. The measures needed to mark one multi-array cell are
1. Move and location of the section within the area.
2. Fiducial place detection (optional)
3. Marking of the primary signal in the array
4. Evidence of the notable 2D matrix code (optional)
5. Movement of the laser marking check out the next world in the range.
6. Be taught more on this affiliated essay by clicking the ems companies. Repeat steps 3 and 4 for the residual circuits in the array.
7. This elegant webaddress paper has a myriad of wonderful lessons for the purpose of this enterprise. Transportation of the panel out of the laser marking system (associated with taking the next panel in)
Cost of Operation
Cost of operation is much less than $1.00 per hour. Normal utilities requirements are 110VAC, 1-phase, 12A. A compressed air supply is necessary for your pneumatics. Full tools fees at maximum laser power (the laser should actually operate at less-then 80-90 rated power) are $0.12 hourly. The principal consumable object is the CO2 laser tube that must definitely be replaced every 3 to 5 years at a price of usually $1,000.00 to $1,500.00. Assuming a 40-hour workweek and tube life of 36 months, the tube replacement cost would mean $0.18 per hour for an overall total operating cost of $0.30 per hour under worst case conditions. Actual operating costs is going to be lower due to less-than maximum electrical use and longer tube life.
For standard pcb laser marking purposes, the cost for marking is significantly less than $0.0003 per signal.
Summary
The electronics industry has been looking for a price and technically effective means of using machine-readable codes to printed circuit boards since the 1980's. Early efforts involved laser marking linear barcodes alongside enterprise traces, also a challenge for bar-code readers, and marking linear barcodes on the table edge, a difficult challenge for reader stance. Bar-code content was limited to a couple figures as a result of limited space and the barcodes character-per-inch capacity.
The development of the 2D matrix code with the permanence, resolution and speed of beam-steered laser marking technology now offers companies a flexible, cost-effective, reliable and verifiable way to uniquely identify every solution through after-sale, distribution and manufacturing.