Laser Marking of ECC 200 2D Matrix Codes on Printed Circuit Boards

Makers of digital products, from house audio machines to automotive keyless entry devices, are more and more trying to get a dependable, price successful system for uniquely figuring out and monitoring products and solutions by the producing cycle, product sales distribution and right after-sale guarantee verification. An automated, automatic monitoring program necessitates that a long term, device-readable code be utilized to an inside printed circuit board to uniquely discover each and every solution. The code will have to be resilient more than enough to endure producing procedures which include wave solder and board cleansing, will have to not have an effect on circuit general performance, and will have to retailer data in the modest place obtainable on true-estate aware printed circuit boards.

The Second matrix code presents a usually means to retailer alphanumeric character strings in really modest locations of the printed circuit board. Laser marking technological know-how presents a system for completely making use of Second matrix codes to most board substrates. The superior-resolution and superior-precision of beam-steered laser marking devices presents the usually means to generate perfectly outlined, superior dependability codes irrespective of code measurement. Laser marking also presents the consumer with a computer system-managed marking method for straightforward implementation into automatic solution monitoring devices.

ECC 200 Second Matrix Codes

Two-dimensional symbologies encode data in the type of a checkerboard sample of on / off cells. Distinct pros of Facts Matrix codes more than typical 1D barcodes contain:

· Encode data digitally, as opposed to the analog encoding of info in typical barcodes.

· Can accommodate reduced-distinction printing immediately on pieces devoid of necessitating a label

· Present really superior data density – the greatest between other prevalent Second codes, which usually means that you can position a good deal of data in a really modest place.

· They are scalable, which usually means that you can print them and examine them in a variety of concentrations of magnification – only restricted by the resolution of the obtainable printing and imaging tactics.

· Owing to the superior data density inherent to Facts Matrix codes, they also offer you designed-in mistake-correction tactics which make it possible for totally recovering the concept encoded in a Facts Matrix image even if the mark is weakened and lacking as significantly as 20% of the image.

· They are examine by video clip cameras as opposed to a scanned laser beam applied for reading through typical barcodes, which usually means that they can be examine in any orientation.

ECC 200 Facts Matrix is ​​the most well known two-D symbology with substantial use in automotive, aerospace, electronics, semiconductor, health care products and other producing device-degree traceability apps. Facts Matrix codes are ordinarily not repetitive typical linear barcodes, but are staying applied in which standard barcodes have been much too substantial, did not offer adequate storage capability, or have been unreadable.

Facts Matrix Code Composition

The Second matrix codes show up as a &quotcheckerboard&quot with the unique squares (cells) in possibly on on (white) or off (black) condition. The code is made up of 4 distinctive components.

· The Finder &quotL&quot Sample is made up of a strong row of cells alongside the still left edge and base of the code that orients the reader to the structure of the Second code.

· The Clock Monitor is a sequence of on / off cells alongside the suitable edge and best of the code that layout the row / column depend to the reader.

· The Facts Location is the sample of black and white cells in the L sample and the clock tracks that incorporate the alphanumeric content material of the code.

· The Tranquil Zone all-around the code will have to be totally free of any functions that might be noticeable to the reader. The tranquil zone should really be at the very least two rows / columns extensive for codes produced of sq. cells. The tranquil zone should really be at the very least 4 rows / columns extensive for codes produced of round cells (dots).

ECC 200 Facts Matrix codes can retailer up to three,116 numeric, two,335 alphanumeric people or one,555 bytes of binary data in a 144 column by 144 row array. Much more reasonable image proportions for printed circuit boards can nevertheless incorporate a important quantity of data.

Laser Marking Technique

The laser marking program is made up of the laser supply, the beam-shaping optics, and the beam-steering program.

The laser is a gentle amplifier producing a vibrant, collimated beam of gentle at a certain wavelength. For FR4 and solder mask apps, most end users opt for the air-cooled CO2 laser running at the 10,640nm much-infrared wavelength. This laser presents many general performance and price pros, and generates great marking benefits.

The laser beam is projected by two beam-deflecting mirrors mounted to superior-velocity, superior-precision galvanometers. As the mirrors are rotated underneath path of the program computer system, the laser beam scans throughout the goal marking surface area to &quotdraw&quot the preferred marking graphic.

Following the laser beam is defected from the beam-steering mirrors, it is concentrated to the smallest location feasible by flat-industry concentrating optics. The flat-industry concentrating assembly is a multi-aspect optical machine built to preserve the focal aircraft of the concentrated laser beam on a reliably flat aircraft by the marking industry. The concentrated laser gentle noticeably will increase the electricity density and connected marking electricity.

The functionality of the laser optical teach is to emphasis the laser beam to a modest location and to scan the laser beam more than the goal surface area with superior velocity and precision. With the CO2 laser configuration, the concentrated location diameter and connected marking line width is about .0035 &quotto .004&quot. Male-readable textual content people can be as modest as .40 &quotand Second matrix codes can be produced from unique functions as modest as a one .004&quot dot.

PCB Marking

To mark printed circuit boards, the warmth produced by the laser beam thermally alters the surface area of the board to generate a contrasting, authentic mark. The method does not involve labels, stencils, punches or any other auxiliary components or consumable.

For printed circuit board apps, many distinct versions of this strategy can be applied for distinct board / coating components and history problems.

· Solder mask or other Conformal Coatings on FR4 Boards –

The laser beam can change the texture of the coating, supplying it a lighter distinction overall look, or can absolutely get rid of the coating to expose the underneath substrate or copper floor aircraft.

· Uncoated FR4 –

The laser beam alters the texture of the surface area of the FR4 manufacturing a close to white overall look.

· Silk-screened Ink Block –

For end users who previously silkscreen ingredient identification or other preset data on the boards, a silk-screened white ink block can functionality as a history to the Second matrix code to improve readability. This strategy is specifically beneficial when …

o The history coloration of the board is equivalent to the coloration of the laser mark.

o Fundamental circuitry would obscure the marking graphic to code visitors.

o The board product is not suited for laser marking, these as ceramic substrates.

Second Matrix Code Verification

Verification of the jurisdiction and content material of the Second matrix codes is an essential action in the total good quality method. Following marking of each and every circuit, the reader verifies the integrity of the mark in advance of indexing the laser marking head to the future marking locale. The reader retrieves the alphanumeric textual content string from the Second code and compares it with the textual content string that was to be marked.

The reader also evaluates the legibility of the code dependent on a range of parameters which include foreground / history distinction, geometric precision (skew, squareness, etcetera.) and the demographic precision of equally the marked and unmarked cells. The Second matrix codes are then classified as handed (environmentally friendly), warned (yellow) or unsuccessful (crimson). For total output effectiveness, the laser program can be programmed to confirm only a pick out couple Second codes on a panel, then to routinely change to verifying each and every code if the code legibility falls underneath a specified degree.

Now&#39s visitors do an great position reading through lessen distinction Second codes. If the laser marking program is mounted on an assembly line with more mature Second matrix visitors downstream from the laser marker, the verification reader can be configured to appraise the codes dependent on the general performance of the more mature downstream visitors to guarantee constant general performance by the assembly method.

Marking Overall performance

The standard printed circuit board marker is a totally automatic, SMEMA-compliant, by-conveyor laser marking program. The total efficiency of the laser marker is comprised of many techniques that make up the marking cycle. The techniques necessary to mark just one multi-array panel are …

one. Transportation and positioning of the panel in the marking place.

two. Fiducial locale detection (optional)

three. Marking of the to start with circuit in the array

four. Verification of the marked Second matrix code (optional)

five. Movement of the laser marking head to the future circuit in the array.

six. Repeat techniques three and four for the remaining circuits in the array.

seven. Transportation of the panel out of the laser marking program (synonymous with bringing the future panel in)

Charge of Procedure

Charge of procedure is significantly fewer than $ one.00 for every hour. Common utilities necessities are 110VAC, one-stage, 12A. A compressed air supply is necessary for the pneumatics. Complete utilities charges at optimum laser electricity (the laser should really really run at fewer then 80% rated electricity) are $ .12 for every hour. The main consumable product is the CO2 laser tube that will have to be changed each individual three to five yrs at a price of ordinarily $ one,00.00 to $ one,500.00. Assuming a 40-hour workweek and tube lifestyle of three yrs, the tube substitute price would equate to $ .18 for every hour for a whole running price of $ .30 for every hour underneath worst circumstance problems. Genuine running charges will be lessen because of to fewer than optimum electrical utilization and more time tube lifestyle.

For standard pcb laser marking apps, the price for marking is fewer than $ .0003 for every circuit.

Summary

The electronics field has been exploring for a price and technically successful usually means of making use of device-readable codes to printed circuit boards considering that the 1980&#39s. Early makes an attempt provided laser marking linear barcodes on the board edge, a challenging obstacle for reader alignment, and marking linear barcodes future to circuit passages, also a obstacle for barcode visitors. Barcode content material was restricted to a couple people because of to restricted place and the barcodes character-for every-inch capability.

The enhancement of the Second matrix code mixed with the resolution, permanence and velocity of beam-steered laser marking technological know-how now presents makers a dependable, price-successful, versatile and verifiable usually means to uniquely discover each and every solution by output, distribution and right after-sale.

Source by Rick Stevenson