Cambridge Technology has been manufacturing ultra-lightweight coated beryllium mirrors for over 50 years. These mirrors, which are integrated into laser beam steering assemblies, are used in various applications from PCB drilling to laser eye surgery.

Challenge:
The exacting nature of the mirrors manufactured by Cambridge Technology require laser interferometry to measure the surface form of almost every precision beryllium mirror it produces. The company also depends on laser interferometry at various stages in the production lifecycle for a clear understanding of performance characteristics.

The company’s original laser interferometry solution was deficient in two key areas. First, it was prone to environmental vibrations, and second, measurement data was stored as individual text files (or text reports) which meant that it was extremely difficult to analyze.

Each unique mirror in the Cambridge Technology range required a different application which, in turn, required specific configuration of the laser interferometer.

To overcome these deficiencies, the company required a metrology solution that would promote process automation. They also needed a solution that would relieve manual workload while minimizing sensitivity to environmental vibration.

Solution:
They replaced existing laser interferometers with current generation instruments operating on ZYGO's Mx software. This immediately allowed the company to realize improvements in processing times and a reduction in operator errors.

Greg Salter, Quality Engineer at Cambridge Technology continues, “The reduction in processing times comes as a result of our ability to customize Mx™ using scripting. The reduced processing times for parts with multiple masks (apertures) has been a massive improvement, along with the removal of the necessity of operators from having to manually load each mask, or having to select different parts of a mask to re-analyze different apertures of a mirror.”

Using ZYGO’s Mx™ software and Python scripts, Cambridge Technology now has a database of all its parts, with corresponding tolerances, settings and masks that is easily selectable by the operator.  Tolerances can be adjusted remotely in a centrally located database by the production engineer without disrupting the production workflow.

Salter explains, “MX loads the correct masks and tolerances for each part automatically by selecting the part number from a drop-down menu. The ZYGO laser interferometer software can now automatically load and swap different masks during measurement without operator input, which means measurement is quicker, throughput of mirrors is increased, and operator errors have been reduced. This has already enabled us to use control limits at various manufacturing stages to ensure that the mirrors will be compliant at the end of the manufacturing process. As we continually improve our methods of manufacture, the analysis that this system provides will enable us to gradually reduce how many mirrors we inspect per batch of mirrors, whilst still providing flatness compliance.”

It was vital that whatever software solution Cambridge Technology chose could be deployed over multiple instruments across manufacturing facilities in multiple locations to support a 24/7 manufacturing operation. Minimizing the amount of downtime and levels of operator training were a must, and this was achieved through a good partnership between ZYGO and Cambridge Technology.

The Results:
Using ZYGO’s Mx™ metrology software, Cambridge Technology has now upgraded the capabilities of its interferometers, realizing significant savings. This has led to the company being able to realize cost savings by removing bottlenecks in production and quality control, and in turn has provided better utilization of staff resources and an overall improvement in manufacturing efficiencies.