Infrared Soldering Equipment

Posted on July 26th, 2010 by admin

Laser marking ECC 200 2D Matrix codes printed circuit

Manufacturers of electronic devices, home audio systems automotive keyless entry, are increasingly seeking a reliable, cost-effective for uniquely identifying and tracking products through the cycle manufacturing, sales distribution and after-sale check the warranty. An autonomous, automated tracking system requires that a permanent machine-readable code is applied to an internal printed circuit board for different products. The code must be strong enough to survive process manufacturing including wave solder and board cleaning, must not affect circuit performance and must store the information in the small space PCB real estate boards conscious.

The 2D matrix code provides a means to store alphanumeric strings in very small printed circuit board. Laser marking technology provides a method for the continuous implementation of 2D matrix codes to most board substrates. The high resolution and high accuracy of the beam-steered laser marking systems provides the means to create well-defined, high reliability code regardless of the size of the code. Laser marking also provides the user with a marking process controlled by computer for easy deployment in systems automated monitoring of the product.

ECC 200 2D Matrix Codes

two-dimensional symbologies encode information in the form of a chess board on / off cells. Specific advantages of Data Matrix codes over conventional 1D bar codes are:

· Information Digitally encode, unlike analog encoding of data in conventional barcodes.

· Can accommodate low-contrast print direct the parties without a label

· Offer very high density of information - the highest among other common 2D codes, which means you can put a lot of information in a very small area.

· They are scalable, which means you can print them and read them various levels of magnification - only limited by the resolution of printing and imaging techniques available.

· Due to the high information inherent density Data Matrix codes, they also offer built-in error correction techniques that allow a full recovery in the encoded message a symbol of the data matrix even if the mark is damaged and missing up to 20% of the symbol.

· They are read by the cameras video instead of a laser beam used to scan conventional barcode reading, which means you can read in any orientation.

ECC 200 Data Matrix symbology is the most popular 2-D with extensive use in automotive, aerospace, electronics, semiconductors, medical devices and other manufacturing applications at the unit level traceability. Data Matrix codes are generally not to replace conventional linear bar codes, but using traditional bar codes, which were too large, did not provide enough storage capacity, or were unreadable.

Structure Data Matrix Code

The 2D matrix codes appear as a checkerboard () with the individual squares (cells) in both the on (white) or off (black) state. The code consists of four different elements.

• The Finder (L) Plan is a solid row of cells along the edge left and bottom of the code that directs the reader to the available 2D code.

• The clock track is a sequence of on / off cells along the right bank and top of the code indicating the row / column to tell the reader.

• The data region is the pattern of target cells and black in the pattern of L and the tracks clock that contains the contents of the alphanumeric code.

• The quiet area close to the code must be free of feature likely to be visible to the reader. The quiet zone must be at least two rows / columns wide for codes constructed of square cells. The quiet zone must be at least four rows / columns wide, built to the codes of the circular cells (points).

Data Matrix ECC 200 codes can store up to 3116 numeric or 1555 alphanumeric characters 2335 bytes of binary information in a matrix column by 144 row 144. More realistic symbol dimensions for printed circuit boards may still contain a significant amount of information.

Laser Marking System

Dialing laser system is the source of laser, the beam-shaping optics, and beam-steering system.

The laser is a light amplifier generating a light beam, collimated light at a specific wavelength. For applications and welding mask FR4, most users choose the CO2 laser-cooled air operating in the wavelength Nm 10 640 far-infrared. This laser offers performance and cost advantages, and produces excellent results marked.

Lightning laser is projected through two beam deflecting mirrors mounted at high speed, high precision galvanometers. As the mirrors are rotated under the direction of the computer system the laser beam scans across the target surface marking (tie) in the desired brand image.

After the laser beam deviates from the mirrors beam-management, focuses to the smallest area possible by flat-field focusing optics. The floor-mounted in the field of focus is a multi-element optical design to maintain the focal plane of the laser beam focused on a relatively flat plane across the field marked. Focused laser light significantly increases the power and energy density associated marking.

The function of the laser optical train is to focus the laser beam to a small extent, and to explore the laser beam on the surface the target at high speed and precision. With the CO2 laser configuration, the focused spot diameter and associated marking line width is approximately 0.0035 inch to 0.004 inch. characters in human readable text can be as small as 0.040 inch and 2D matrix codes can be constructed from characteristics individual, and a single inch of 0.004 points.

PCB Marking

On the occasion of printed circuit boards, the heat generated by the laser beam heat alters the surface of the board to create a contrast, legible mark. The process does not require labels, templates, hitting, or any other auxiliary hardware or consumables.

To print circuit board applications, several different variations of this technique can be used for different board / coating materials and background conditions.

· Welding mask or other conformal coating on FR4 boards -

The laser beam can alter the texture of the layer, giving it a more stark contrast, or can completely remove the coating to expose the underlying substrate or ground plane of copper.

· No plaster or coated FR4 -

The laser beam alters the texture of the surface of the FR4 producing a near white appearance.

· Silkscreen ink Block -

For users who already silkscreen component identification or other information set at the tables, a white block silkscreen ink can function as a fund code 2D matrix to optimize readability. This technique is particularly useful when ...

o The background color of the board is similar to the color of the laser mark.

or circuits underlying brand image obscures the code readers.

o The table material is not suitable for laser marking, such as ceramic substrates.

Verification Code 2D Matrix

Verification of the legibility and contents of the 2D matrix codes is an important step in the total quality program. After marking of each circuit, the reader verifies the integrity of the brand before indexing the laser marking head to the following dial location. The reader retrieves the alphanumeric text string 2D code and compares it with the text string was going to score.

The reader also evaluates the readability of code based on a variety of parameters including in the foreground and background contrast, geometric accuracy (slope, angle, etc) and precision dimensional both marked and unmarked cells. The 2D matrix codes are classified as passed (green), warning (yellow) or not (red). For more total production efficiency, the laser system can be programmed to verify only a select few 2D codes on a panel, then to automatically switch the verification of each code if code readability falls below a certain level.

Today's readers to read an excellent work less contrast 2D codes. If the laser marking system is installed on an assembly line with older readers downstream 2D matrix laser marker, the reader can be configured to evaluate check codes based on the performance of older readers downstream to ensure consistent performance throughout the assembly process.

Marked Performance

The typical marker of printed circuit board is an automatic, SMEMA compatible system, through belt laser marking. The overall productivity of the laser marker consists of several steps that make up the marking cycle. The steps required to make a multi-matrix panel are ...

Transportation and positioning of the group in the area of marking.
fiducial location detection (optional)
The delimitation of the first circuit of the matrix
Verification of 2D matrix code marking (optional)
The movement of the laser marking head to the next circuit of the array.
Repeat steps 3 and 4 for the remaining circuits of the array.
Transportation panel laser marking system (synonymous with what the next panel)

Operating Cost

Operating Cost is much less than $ 1.00 per hour. Typical utilities requirements are 110VAC, 1-phase, 12A. A source of compressed air required for pneumatic. Total expenditure on public services a maximum laser power (the laser actually should work less than 80% of rated power) is $ 0.12 per hour. The primary consumable item is CO2 laser tube should be replaced every 3-5 years at a cost of $ 1,000.00 to $ 1,500.00. Assuming a working week of 40 hours and the tube life of three years, the tube replacement cost would amount to $ 0.18 per hour for a total operating cost of $ 0.30 per hour in most difficult conditions. The actual operating costs will be lower due to less power than the maximum use and longer life of the tube.

For typical laser marking pcb applications The cost for marking is less than $ 0.0003 per circuit.

Summary

The electronics industry has been searching for a cost and technically efficient by applying machine readable codes for printed circuit boards since the 1980s. The first attempts laser marking including linear bar codes on the board edge, an alignment challenge for the reader, and make linear bar codes next to the ski circuit is also a challenge for bar code readers. barcode content was limited to a few characters due to limited space and the bar code character per inch of capacity.

The development of 2D code matrix combined with the resolution, permanence and speed of the beam-steered laser marking technology now offers manufacturers a reliable, cost effective, flexible and verifiable uniquely identify each product through the production, distribution and subsequent sale.

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