This gradual approach to photonics automation was challenged when XVP was introduced to the Meca500, Mecademic’s six-axis industrial robot. At a similar price to a three-axis ball-screw linear positioner (only one of the many elements comprising a typical optical assembly system), the Meca500 seemed precise, flexible, and cost-effective enough to bridge to a fully automated photonics assembly and achieve a seamless transition from low-rate initial production to full-scale automated assembly.
However, six-axis robots were not seen as precise enough for optics and photonics tasks, which made XVP weary of using Mecademic’s robot. “When we started discussing using the Meca500 to replace optical positioners, I was skeptical,” says François Séguin, XVP’s President and Founder. “I had been doing that for 40 years, so it was a sort of knee-jerk reaction to go to traditional photonics positioners.”
Determined to validate the Meca500’s potential, XVP embarked on a rigorous series of tests. The Meca500 delivered the precision needed for critical applications like TO-laser diode collimation and objective lens focusing onto CMOS sensors. The Meca500 shined when aligning pre-collimated fiber assemblies, owing to its impressive angular precision. These measurements and simulations confirmed that the Meca500 could be used for photonics alignment in optical systems with focal lengths above 0.5 mm and mode sizes larger than 5 µm.
In addition to those studies, XVP built a photonics assembly application for lens alignment and glue dispensing using one Meca500 in a fixed station. With this setup, they can demonstrate to clients the kind of automation the Meca500 can deliver in real life. These are the main steps in the optical application built by XVP with the Meca500:
- Rest neutral robot position
- Pick up one lens from a lens tray
- Present lens to glue application site and perform glue bond line dispense
- Move the lens over to a selected camera insertion site on the active camera assembly cassette—with a companion movement of a retro-illuminated resolution target over the camera being aligned.
- Live camera image acquisition and sharpness diagnostics over five regions of interest to drive lens placement optimization – stop at optimal lens placement
- Initiate UV cure cycle
- Release the lens and move the robot back to the lens pickup location
- Start over at step 2 while incrementing the target camera and target lens pickup location
One key difference to the traditional systems developed by XVP Photonics is the number of degrees of freedom required to integrate all movements needed for process automation. With the Meca500, a single robot can perform all those movements from a fixed station, simplifying system design. Moreover, with its small size, the Meca500 saves space and is flexible enough to be mounted in various positions over the assembly area. Sébastien Allen, XVP’s Process Development Director, also praises the Meca500’s ease of use and plug-and-work capabilities, enabling quick integration. The robot’s primary benefit to him, however, is the repeatability. “By removing the human factor when you apply the glue or align the lens, you have optimization. You don’t have to realign it. Everything is where I should be.”.
