Printed circuit boards (PCBs) are used today in nearly every electrically controlled system in the world. The form and functionality of the boards are just as varied as the fields in which they are used. In all cases, printed circuit boards contain small control components that can have a major impact on the performance of the finished product, so no errors or mix-ups may be allowed to occur in their manufacture. Rommel GmbH, based in of Ehingen, Germany, uses lasered Data Matrix codes to ensure that the boards are produced without errors.

　　The application of codes and inscriptions by laser is performed by ablation or by conversion of solder paints. This delicate process requires the utmost precision. The new laser marking system from Rommel GmbH uses an innovative laser scan head that features a moving deflection mirror. CO2 lasers and the In-Sight® 5100 vision system to reach its precision goals.

Compact process
　　The WL 700 LCS laser marking system from Rommel not only applies codes and inscriptions, it can also counter-check them in fractions of a second. The intelligent and compact In-Sight 5100 vision system fulfills three important functions: it measures the board, reads the codes and inscriptions, and evaluates their quality. Based on the compressed process, the performance and marking speed of the laser can be configured easily and accurately in order to achieve consistently high code quality. In this way, the inline system from Rommel processes PCBs of various sizes, materials, and thicknesses of solder paint quickly and reliably.

Integrated system
　　Speed plays a crucial role in the manufacturing process of PCBs. The entry and exit time and the marking and control time were permanently optimized in the WL 700 LCS. The growing demands for speed and accuracy have been met by simultaneous deflection of the laser beam onto the boards and the counter-checking of the code with the vision system integrated into the beam path. In addition, a newly developed transport system with middle-supported conveyor belts permits full-area inscription as far as the edge area of the PCB. The inscription area measures an impressive 400 x 400 mm.

Shortened cycle times
　　Shorter paths save time. Thus, the WL 700 LCS has no need for a conventional XY table. Instead of the moving product, a two-axis deflection system consisting of two swiveling mirrors ensures a large inspection and working field. Movable lenses focus the laser beam on the Z-axis. An F-Theta lens was not used so as to integrate the camera system downstream of the laser optics into the scanning head. The In-Sight 5100 is integrated via a half-silvered mirror. Rommel GmbH makes use of zinc selenite components in the lenses. These do not react to the laser at the high wavelength of the CO2 laser of about 10,000 nanometers - in contrast to conventional glass.

Increased reliability
　　For two-sided inscription of PCBs, the system is optionally equipped with a second laser camera system that simultaneously labels and checks the front and back sides. The combination of the laser and the intelligent vision system in one scan head pays dividends. The marking and control system from Rommel applies five Data Matrix codes with a size of 3 x 3 mm each from the top and bottom in just eight seconds including handling, fiducial measurement, and quality evaluation. In this way, the WL 700 LCS sets new standards.