Inspecting PCBs with blue dots

Canadian-based Original Solutions has developed a series of products to optically inspect PCBs, increasing yields at final test by over 50%.

The ‘Blue Dot’ system developed by the company employs a simple technique where markers (blue dots) are strategically placed around and below components.

The blue dots fluoresce under UV light showing components that are missing, in reverse polarity or misaligned. The technique also highlights solder shorts, making for fast inspection with 100% accuracy.

The technique overcomes some of the greatest problems with today’s optical inspection techniques, particularly the problems of false calls and undetected errors.

There are various entry levels for small, medium and large companies, allowing users to upgrade from quick-to-install manual set-ups to fully automated in-line systems.

Built into the production line, the DOTector Inline Vision Inspection System for PCBs can inspect up to 300,000 components per hour. A ‘DOTector’ communicates with the embedded ‘Blue DOT’ signature in the PCB, virtually eliminating the need for programming.

The system self-calibrates and is self-taught using the customer’s PC Board data and Gerber files. The system can be used to detect: presence/absence, polarity, wrong component, solder bridges, all leaded packages down to 10 mil pitch, extra components, components skid/skew for parts as small as 0201s, tombstoned components, billboarded components and through hole components.

The Blue CAM 1000 video/camera system, on the other hand, features a custom ultra-violet/ambient light source and a specially designed camera system allowing the user to zoom in on components while maintaining a large view of the board. It allows users to find the most glaring defects on a PCB quickly and easily. Blue CAM is equipped with auto focus and a simple to use UV/Ambient foot pedal.

The Blue DOTscope can be used for the manual inspection of assembled PCBs. In operation, it allows the user to toggle between UV and ambient light for Blue Dot or regular inspection detecting missing parts, misalignments, shorts and polarity.

Finally, the company’s Blue Dot generation software can be used to modify board design to indicate placement of Blue Dots.

The systems are now being distributed in the UK by Accelonix.