Friday, May 25, 2018
Publication Date: 09/1/2008
Archive >  September 2008 Issue >  Electronic Mfg. Services > 

100% Yields with Solid Traceability

New MP3 players from a global electronics manufacturer like Sony are destined for a demanding consumer market and cannot be compromised in any way. In Malaysia, the company sought a code reading and traceability solution for the PC boards for these products. This kind of product tracking is essential, especially for a company like Sony.
This traceability helps to protect the company against costly recalls and product mix-ups as well as allowing for "damage control" in the event of a problem. Previously, badly read codes and the resulting rejection rates were costing the company a lot of money in terms of rework and rejected units. Their old code reading system was simply incapable of rising to the challenge, so Sony in Malaysia is now using the In-Sight® 5110 for code reading on PC boards destined for new MP3 players.
Each PC board passes along a conveyer on 9 production lines and is marked with a Data matrix code measuring only 1 x 1mm in size, containing product information in 10 characters. Production volume at the plant is very high — 40,000 units a day — so the reading solution deployed should guarantee a read rate of 100 percent thus allowing the production line to work nonstop, eliminating downtime. The existing code reading solution was clearly not up to the challenge with an average rejection rate per week of 10,000 units, a level that was costing the company money and was delaying time to market for an important product.
Meeting the Challenge
It is vital that the serial number marked on each PC board that is heading for product assembly lines be identified and tracked. If the code reader is not capable of adjusting to the product changeovers on production lines, a serial number can be missed and data is lost. No two read points are the same. Lighting, environment, or the way the piece is presented can differ greatly, so what is needed here is a code reading system that has the robustness and flexibility to perform reliably under the many variations in conditions. Sony tested a number of different readers that are available on the market.
The final result was that the only reader capable of meeting the company's expectations was the Cognex In-Sight 5110 ID reader. The 5110 outperformed its rivals in a number of critical areas. It provided a superior read rate in terms of decoding speed and sturdiness; the In-Sight 5110's new perspective distortion support ensures reliable reading even when at an angle to the PC boards. The job is stored in the reader in such a way as to attempt reading several times using different exposure values — adapting itself to the surface of the PC board, thus increasing the chances of successful reading. No reader retraining is required for a product change, while there are flexible multiple communication channels. The reader provides versatile data gathering, essential for a factory database. Unlike other systems, the In-Sight 5110 can also ensure reliable OCR.
The In-Sight 5110 ID readers are now installed on 9 production lines, having replaced the older readers that had not been doing the job. Code reading time is now 2 seconds per read whereas competitive systems took over 10 seconds to provide a reading. Code reading success rate has increased from 95 percent to 100 percent. With a 100 percent successful code reading rate, the production line no longer has to stop as a result of a badly read code. There is no longer the need to stop the line for product repositioning or focus adjustment. These factors are already saving Sony about $5,000 a week. This calculation comes from the 5 percent failure rate within 200,000 units per week based on a unit cost of RM1.5. The company expects a return on the investment within 10 months.
TK Tan, Staff Engineer at Sony, Penang says: "The fact that we have improved our code reading times and increased our success rate to 100 percent saves us valuable time and boosts our production efficiency — we hope to implement these vision solutions elsewhere for other OCR applications".
Contact: Cognex Corp., One Vision Dr., Natick, MA 01760-2059 877-264-6391 or 508-650-3000 fax: 508-650-3333 Web:

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