Assembled printed circuit boards are central components in the control and regulation of electronic machines, drives and devices. The demand is high and they are manufactured fully automatically in plants.
PCB thicknesses today are in the millimeter range and separation processes mean a considerable mechanical load. Resistors, microcontrollers and capacitors arranged close to the scribe groove in a very confined space could suffer damage. Modern PCB separators like those of the cab MAESTRO series have therefore been developed for low-stress separation and optimized for a wide range of requirements. For example, with the MAESTRO 4S (Fig. 1), the milled groove can be traversed several times with the roller blade - special blade settings provided, even with aluminum circuit boards. Even passing the knife over the scribe groove twice with motorized readjustment of the knife distance further reduces the stresses. High-quality cut-off points significantly improve the quality of the printed circuit boards. Cut-off lengths of up to 600 mm are infinitely adjustable. With the MAESTRO 5L device type, up to 15 printed circuit boards arranged next to each other can be separated simultaneously. After separation, the PCBs are conveyed onto an integrated conveyor belt. The MAESTRO 6 was developed for applications with extra-long materials up to 1,500 mm in length.
"Proven manufacturing equipment allows a high degree of automation and thus contributes to an economical electronics production in the factories."
Placement systems of the latest generation are customized several times a day. To transport different sizes of printed circuit boards, magazines must be constantly adjusted to new widths (Fig. 2). Depending on the magazine, the width is adjusted by screw clamping, by means of a toothed belt either by hand or by motor. PCB magazines of the cab 800 series are equipped with a clutch. When inserting a magazine into the loader of a placement system, the flange on the servomotor of the loader connects to the clutch. The movable side wall of the magazine moves evenly and precisely to a reference point on threaded spindles. Parallelism is ensured in this process. The magazine then automatically adjusts to the width of the printed circuit board specified by the system control. There is no need to stock preset magazines. Human errors are avoided and process quality increases.
At the SEW Eurodrive electronics plant in Bruchsal, Germany, about 350,000 PCB are produced every month. These are automatically fed from such magazines to the placement system every day. At the end of the line, mobile transport systems pick up the magazines without a driver, together with all their process-relevant data. Flat modules assembled on one side are transferred to the next production step. If printed circuit boards are to be assembled on both sides, these magazines are transported back to the beginning of the line by the mobile assistant. The flat modules are turned to the opposite side, fed to the system and the assembly process starts again.
These applications show that today, professional technology can be used to safely and economically separate and transport printed circuit boards under a wide variety of conditions.
Lead picture: cab Produkttechnik GmbH & Co KG
MAESTRO 4S depanelling in videos: www.cab.de/en/maestro4s-tutorials
Series 800 transport magazines operated at SEW Eurodrive: www.cab.de/en/sew-video
12 February 2021
- Laser, Depaneling machines
- Assembly techniques