Home > Rapid motion for vision inspection

Rapid motion for vision inspection

Supplier News
article image AmFax’s Precision Vision system.

A BALDOR linear motor positioning stage, available in Australia from Australian Baldor , has helped AmFax to deliver a compact and high-throughput vision system for the production testing of Cinch's unique CIN::APSE range of connectors for state-of-the-art microprocessors.

Designed for mounting high-end server and workstation processors onto PCBs, a CIN::APSE socket contains as many as 1296 wire filament contacts on a 1mm pitch, with a profile as short as 0.8mm.

AmFax's customised automatic test equipment (ATE) - Precision Vision - verifies the manufacturing integrity of each of these contacts using a number of vision testing techniques.

Each test sequence is performed on a fixture containing 20 connectors - and up to 26,000 individual test points - demanding a camera positioning system capable of making rapid and precise moves.

The sheer throughput required, coupled with the compactness of linear motor technology compared with rotary-driven alternatives, convinced AmFax to go straight for a linear motor based solution.

Baldor helped AmFax to specify the X-Y motion subsystem, choosing a dual-axis linear stepper motor stage from its LMDS series, capable of accelerations to 19.62 metres/sec/sec (2G) and a movement resolution of 2.5µm.

This stage, with a travel area of 300 x 200mm, carries a high-resolution camera fitted on a third motion axis for fine positioning - a load totalling around 2kg.

In use, the stage makes around 1600 moves to test the 20 connectors in each fixture, grabbing an image of a 4 x 4 array of contacts at each step.

The compactness of the stage compared with alternatives such as rotary motor driven ballscrews - with everything contained within the platen's 300 x 200 mm frame - was a key attraction for AmFax.

It allowed the final test system to be implemented in a compact benchtop form factor resembling a photocopier - with clear access to the test area.

With such a rapid and high number of moves, the 'zero-maintenance' nature of the LMDS stage with its air bearing, was another important factor for AmFax in providing a robust and repeatable test system suited to the rigours of intensive production testing.

"Linear motor technology has proved to be an enabling technology for this area of automatic testing, delivering the speed required for economic production testing sequences", says Simon Pape, design engineer at AmFax.

"The ergonomics of the ATE solution was also aided by the motion technology - providing unobstructed access to the test area for changeover of units under test".

The Precision Vision system is controlled by a PC running LabVIEW, and a suite of test software developed by AmFax. The motion control is provided by a plug-in motion PCbus controller card.

Newsletter sign-up

The latest products and news delivered to your inbox