Product Details Supplier Info More products

An electronics manufacturer is using a Cognex Dataman 100 ID reader to help prevent incorrect parts being added to assemblies.

The solution also helps prevent incorrect operations from being performed on the assemblies – with these two problems previously costing the manufacturer several hundred thousand dollars a year.

The difficulty in tracking assemblies made it necessary to keep more than the desired amount of work-in-process (WIP) inventory.

A further challenge resulted from a limited amount of space on some of the assemblies.

Claire Lasers developed an application that uses a laser to apply a 2D Data Matrix code to each part.

The 2D Data Matrix codes can incorporate more information than traditional 1D codes.

The 2D codes can also be directly marked onto parts as they do not need the contrast used by 1D codes on labels.

A Cognex Dataman 100 ID reader then checks each 2D code for readability immediately after marking.

From this point, the assembly is inspected prior to each critical operation to ensure the correct components are installed and the right operations are performed.

The laser marking and image-based ID readers have eliminated the problem of incorrectly labelled or identified parts in the manufacturing process, enabling the manufacturer to substantially reduce WIP inventory.

The electronics manufacturer produces thousands of different part numbers of high value electronic products intermixed on the same assembly line.

The large number of different products built on the line, coupled with the fact that many of the parts that distinguish these products are so similar, made it difficult for assemblers to verify they were assembling the products correctly.

The difficulty in identifying parts combined with the fast pace of the assembly line resulted in a large amount of assemblies requiring rework or scrapping.

An additional issue was the inability to easily track the WIP inventory, which resulted in large amounts of money tied up in raw materials in process.

The finished assemblies have much higher value than the parts used to create them, so the company was concerned its inventory records did not accurately reflect the value of products in its facility.

The two most popular methods of marking electronic components are inkjet printing and laser marking.

Inkjet printing utilises a transfer printer that applies ink to the surface of the assembly.

The main drawbacks of the ink printing process are the lack of durability of the printing and the difficulty in providing serialised part tracking.

Laser marking, on the other hand, offers an easy way for electronics manufacturers to create permanent abrasion-proof marks on their products that are resistant to chemicals such as solvents and oils and can withstand even the harshest of environments.

In addition, laser marking ensures that fragile parts are protected and do not suffer from any thermal stress during the laser-marking process.

These features – coupled with its fast throughput – have made laser marking the method of choice for marking in the electronics industry.

The manufacturer asked Claire Lasers and other laser identification system-suppliers for solutions to its problems.

The application was particularly challenging because the space to apply identification was limited on many assemblies and the high value of the assemblies demanded 100 per cent accuracy.

Another concern was that the assemblies were not positioned and fixtured on the assembly line with the level of accuracy normally required for laser inspection and image-based ID reading.

Denis Gendron, president of Claire Lasers, worked with the manufacturer to define the requirements of the application.

He developed an application for his company’s Clearmark laser-marking system capable of generating a 2D Data Matrix code in the required space.

The Clearmark laser is a 10kW all solid-state 1065nm laser with a repetition rate of 10-80kHz, pulse duration of 100 nanoseconds, maximum pulse energy of one millijoule and maximum peak power of 10kW.

The laser is packaged in a standard 19in rack configuration with air cooling.

It measures 16.8 x 5.6 x 4.6in (426.7 x 142.2 x 116.8mm) and weighs 17.5lbs (7938g).

The controller is 24.3 x 7.0 x 190in, weighs 53lbs and has a USB interface.

Successful adoption of 2D Data Matrix codes in the manufacturing process requires reading rates that meet or exceed the read rates achieved with traditional 1D barcode technology.

Laser marking sometimes produces codes with low contrast, poor cell position or inconsistent cell size.

In addition, the surface being marked can be matted, cast or highly reflective.

Reading such marks can present a difficult challenge.

To overcome the direct part-mark printing challenges, Clare Lasers selected the Dataman 100 fixed-mount readers from Cognex, which incorporate reading software that can locate and read the 2D data matrix codes despite the range of surfaces, print quality, angles and contrast changes.

The recently approved AIM (Association for Automatic Identification and Mobility) Direct Part Mark (DPM) Quality Guideline DPM-1-2006 provides the necessary metrics and lighting definitions to handle the variety of marking techniques and part materials used in DPM applications.

Data Matrix codes are imprinted using a variety of methods, so their colour and shape can deviate considerably and the variety of surfaces and materials on which they are imprinted rarely provides a uniform white background.

The AIM DPM Quality Guideline was built off of the ISO15415 standard, which permitted only one lighting configuration, while the new standard specifies four configurations, including the addition of directional lighting.

The new standard also outlines a defined method for setting the optimal image brightness, which provides a range of exposure and gain settings to compensate for the differences in surface reflectance in DPM applications.

Gendron said: ‘I picked the Dataman 100 ID reader to address the 2D Data Matrix code reading challenge because, in my experience, its software consistently delivers reliable readings even when the appearance of the code has been degraded.

‘The Dataman user interface is exceptionally easy to use.

‘The small size of the Dataman readers makes them ideal for cramped assembly-system applications.

‘The Cognex sales team provided us with excellent information during the selection process and their service and support has been excellent,’ he added.

The Dataman 100 measures 55 x 42 x 22mm and weighs 125g.

It uses IDQuick software, a Cognex decoding tool for ultra-fast reading of well-formed codes.

Cognex also offers IDMax decoding software to read the most challenging codes.

All Dataman 100 readers offer easy set-up with integrated illumination, beeper, adjustable optics, a built-in aimer and a push-button trigger.

The Dataman 100 products also include the Dataman 100 Verifier Systems, which have the software, integrated lighting and optics to provide true code-quality verification to the latest AIM DPM Quality Guideline.

Gendron and his team designed a motorised platform that moves the reader into position based on the location of the assembly or part prior to reading.

The motor moves the reader around the station until the reader locates the part.

The station locates the assembly and reads the code in a couple of seconds, which is fast enough for the application.

The speed could easily be increased by using a faster linear-motion system.

Claire Lasers also provided the Clearview solution to integrate the marking system in the factory-control system.

This communication is triggered by an operator scanning a work-order code.

The data is retrieved from the manufacturing database and is shown in a human machine interface for potential operator inspection.

Parts are then laser marked with the Clearmark laser-marking system based on the retrieved data.

A serialised 2D Data Matrix code is applied to the subassembly after it has been completely processed and inspected.

The carriers that hold the subassembly also receive a 2D Data Matrix code.

This is because the manufacturer has made a substantial investment in tooling for this application and wants to carefully manage this investment as well.

The marks on the container can be erased, making it possible to remark the container when needed.

The containers are divided into groups according to which type of assembly they are carrying.

One container in each group also has a standard 1D group-control barcode.

The group-control barcode determines which channel or stations the groups of containers will be directed to on the line.

Gendron continued: ‘The laser marking and image-based ID reader have helped the electronics manufacturer substantially improve the performance of its operations.

‘The identification of the part at each critical station of the assembly system provides the ability to accurately track the assembly process, avoid operator error and has dramatically reduced scrap and rework rates on the line.

‘Marking the incoming inventory with the unique identifier also enables real-time inventory control.

‘Manufacturers are quite pleased with the results of this application and many are looking for other opportunities to apply laser marking and image-based ID reading to generate more quality and productivity improvements,’ he finished.

View full profile