Provides a method for laser marking technology on a permanently applied two-dimensional matrix code board substrate. Laser Marking is an automated product tracking system that allows users to easily perform computer controlled marking processes. The 2D matrix code provides a means to store alphanumeric strings in a very small area of a printed circuit board. Provides a method for laser marking technology on a permanently applied two-dimensional matrix code board substrate.
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Laser engraving, laser engraving, barcode
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From home audio equipment to automotive keyless entry systems, electronic device manufacturers use internal automated tracking systems to identify each product uniquely, through verification of production cycles, sales distribution, and after-sales service guarantees. The permanent machine readable code needs to be applied to the printed circuit board of the. The cord must be durable enough to survive the manufacturing process including wave solder and board cleaning, affecting the performance of the circuit
The 2D matrix code provides a means to store alphanumeric strings in a very small area of a printed circuit board. Provides a method for laser marking technology on a permanently applied two-dimensional matrix code board substrate. Provides a means to create a high reliability code that is manifested despite the high resolution and high accuracy code size of the beam steered laser marking system Laser marking allows the user to control the computer controlled marking process An easy to use automated product tracking system.
ECC 200 second matrix code
Two-dimensional symbols encode information in the form of an on / off cell checkerboard pattern. Characteristic data matrix codes include traditional 1D barcodes:
· Encode digital information, as opposed to analog coding of traditional barcode data.
* Can accommodate low contrast printing of parts directly without requiring labels
· Provide very high information density-meaning that you can put a lot of information in the highest, and therefore very small area among other common second codes
* They are scalable, meaning that you can print them and read them at various levels of magnification-only available printing and imaging techniques
· Due to the high information density inherent in data matrix codes, they are also fully encoded with data matrix symbols, even if the mark is corrupted
* Versus scanned laser beam used to read conventional barcodes, which means that they can be read at any orientation
ECC 200 data matrix is for automotive, aerospace, electronics, semiconductor, medical equipment and other manufacturing equipment level traceability applications Data matrix codes do not usually replace traditional linear barcodes, but traditional barcodes are larger Provide too much storage capacity
Data matrix code structure
The 2D matrix code is displayed as a "checkerboard" with individual squares (cells) in either the on (white) or off (black) state. The code consists of four elements.
* The finder "L" pattern consists of a solid line of cells along the left and bottom of the code that orients the reader into a 2D code layout.
* Clock track is a sequence of on / off cells along the right edge and top of the code that specifies the number of rows / columns to the reader.
* The data area is the pattern of black and white cells in the L pattern and is a clock track that contains the alphanumeric content of the code.
· The quiet zone around the code should have no features that may be visible to the reader. Of quiet importance is the horn cell of code construction for the whole including at least two rows / columns. Of quiet importance is the circular cell (dot) of code construction for the whole including at least 4 rows / columns.
The ECC 200 data-matrix-code can store up to 3,116 numbers, 2,35 alphanumeric characters, or 1,555 bytes of binary information in a 144-row array 144 columns. The more realistic symbol dimensions of printed circuit boards can still contain a great deal of information.
Laser marking
The laser marking system consists of laser light source, beam shaping optics and beam steering system.
Lasers are light amplifiers that produce bright, collimated streaks of light at specific wavelengths. For FR4 and solder mask applications, most users choose an air-cooled CO2 laser operating at a far infrared wavelength of 10,640 nm. This laser has several performance and cost advantages and produces excellent marking results.
The laser beam is projected through two beam deflection mirrors mounted on a high speed, high precision galvanometer. As the mirror rotates under the direction of the system computer, scanning of the laser beam across the surface of the target mark to pull the image of the desired mark.
Laser beam deflection after the beam-steering mirror is the smallest spot with optics in the flat field. Flat-field collection assemblies are designed to maintain the focal plane of the collection laser beam in a relatively flat plane across the entire marking field, significantly increasing the power density and quasi-imprinting power of the concentrated laser beam.
The function of the laser beam train is to focus the laser beam to a small spot and scan the laser beam to the target surface at high speed and accurately. In the CO2 laser configuration, the focused spot diameter and associated marking line width is about 0.0035 "-0.24". The human readable text properties may be 0.040 small and the second matrix code can be assembled from a single 0.004 "dot small individual feature.
PCB mark
In order to mark the printed circuit board, the heat generated by the laser beam changes the surface of the board to create a thermally contrasting, easy-to-read mark. The process does not require labels, stencils, punches or any other auxiliary hardware or consumables.
For printed wiring board applications, several variations of this technology are available for different board / coating materials and background conditions.
* FR4 board solder mask or other conformal coating-
Laser light can change the quality of the coating thereby giving a light and contrasting appearance or dewing the underlying substrate or copper ground plane
* Uncoated FR4-
Laser light changes the surface quality of the FR4 producing a near white appearance.
* Dyed ink block-
For users who have already printed identification of the board configuration or other fixed information, the printed white ink block is readable as background to the second matrix code This technique is particularly useful in the following cases:
o is similar to the background color of the board and the color of the laser mark.
The underlying circuitry of O covers the image of the marking code encoding the reader.
o Board material is not suitable for laser marking like ceramic substrate.
2D matrix code verification
The readability and content verification of the 2D matrix code is an important step in the overall quality program. After marking each circuit, the reader verifies the integrity of the markings before directing the laser marking head to the next marking position. The reader takes an alphanumeric text string from the 2d code and compares it to the marked text string.
The reader also assesses the readability of the code based on various variables including foreground / background contrast, geometric accuracy (tilt angle, etc). Both dimensional accuracy of the cells marked and unmarked). Next, the 2D matrix code is classified as passed (green), warned (yellow), or failed (red). For overall production efficiency, the laser system switches to automatically verify all codes when the readability of the code falls below a specified level
Today's reader is a two-dimensional code for the best job readings. Assembly-process if the laser marking system is installed at the assembly line with the older second matrix reader downstream from the laser marker
Marked performance
A typical printed circuit board marker is a fully automated, SMEMA compliant, conveyor laser marking system. The overall productivity of the laser marker is composed of several steps that constitute the marking cycle. Multi-array panel on the process required to ...
1. Transport and location of panels in the marking area.
2. Reference position detection (optional)
3. Mark the first circuit in the array
4. Two-dimensional matrix code for verification (optional)
5. Movement of the laser marking head to the next circuit of the array.
6. Repeat steps 3 and 4 for the remaining circuits in the array.
7. Transport of panels from laser marking system (equivalent to bringing the next panel)
Cost of operation
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