Z-Laser's machine vision solution for inspection of PCB and micro parts.

Z-Laser's solution for inspection of PCB and micro parts.

To demonstrate the functionality of electronic components, the correct position must be guaranteed for the assembly of components for PCBs.

Lasers are used for this purpose with very narrow lines and a homogeneous intensity distribution. The laser triangulation determines whether all of the required components were located and installed in the required positions.

Various errors can occur during the assembly process of a PCB, which affects the performance of the final product.

Missing components (e. g. SMDs, THTs)
Incorrect positioning of parts (twisted and/or shifted)
Missing or defective solder joints
Faulty coplanarity of ICs

The implementation of laser triangulation permits an early warning of production and assembly defects to the manufacturer. A laser projects lines across the manufactured item which is acquired in real-time by a machine vision camera.

Analyzing the offset of the laser line, a precise 3D profile of the product surface is generated. Based on this data, measurements and golden template comparisons can be accomplished.

Challenging are the very small sizes and the metallic reflective surfaces of the components. Interfering reflection which influence the accuracy of the measurement negatively are the outcome. Illumination like LED’s and standard red lasers are reaching their design limits for this application.

The fiber-coupled ZFSM laser from Z-LASER offers an ideal solution. Line widths down to 6μm (1/e2) and a blue wavelength (450nm) greatly diminish the disturbing reflections from metal parts and solder joints. This allows the achievement of the maximum resolution for the whole measurement application.