ID Readers Accurately Identify and Trace Printed Circuit Boards
- Saturday, 01 December 2007
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 printed circuit boards (PCBs) for these MP3 players.
This kind of product tracking is essential, allowing a company like Sony to protect itself 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. Sony in Malaysia is using the In-Sight® 5110 from Cognex (Natick, MA) for code-reading on PCBs destined for their new MP3 players.
Careful Reading on the Line
Each PCB passes along a conveyer on nine production lines and is marked with a Data Matrix code containing product information in 10 characters measuring only 1 x 1 mm in size. Production volume at the plant is very high at 40,000 units a day, so the reading solution deployed should guarantee a read rate of 100%, thus allowing the production line to work nonstop, eliminating down time. Their previous code-reading solution provided an average rejection rate per week of 10,000 units, which was costing Sony money and was delaying time to market for an important product.
It is vital that the serial number marked on each PCB heading for product assembly lines be identified and tracked. If the code reader is not capable of adjusting to the product changeovers on lines, a serial number can be missed and data is lost. No two read points are the same. Lighting, the environment, or the way the piece is presented can differ greatly, so code-reading equipment that has the robustness and flexibility to perform reliably under the variants in conditions is required.
Sony tested different readers available on the market and chose the In-Sight 5110 ID reader for its read rate in terms of decoding speed and sturdiness, and perspective distortion support that ensures reliable reading even when at an angle to the PCBs. 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 PCB, thus increasing the chances of successful reading. There is no reader retraining required for a product change, and the system offered multiple communication channels for networking flexibility, and reliable original character recognition (OCR).
The ID readers are now installed on nine production lines, replacing the previous readers. Code-reading time is two seconds per read, whereas the other system took more than 10 seconds to provide a reading. Code-reading success rate has increased from 95% to 100%, so the production line no longer has to stop as a result of misread codes. There is no longer the need to stop the line for product repositioning or focus adjustment. These factors enabled Sony to save about $5,000 a week (this calculation comes from the 5% failure rate within 200,000 units per week based on a unit cost of RM1.5).
For more information on Cognex Corp.’s In-Sight 5110 ID readers, visit http://info.hotims.com/10983-144.