Mechatronics for photonics assembly and testing
Today, photonic devices for high-tech applications are becoming increasingly complex. Ever larger numbers of optical elements with diverse photonic properties must be integrated into ever smaller packages.
ficonTEC machines fulfill the definition of state-of-the art mechatronics, encompassing fully-integrated advanced mechanical motion/positioning elements, electronics and instrumentation, together with powerful software tools.
Over time, and with the accumulated experience of an installed base of many hundreds of machines, continued machine development has led to highly modular and fully-integrated platforms and numerous product lines. The result is ever higher levels of performance and reproducibility, and thus higher yield and lower cost/part in the very devices our machines are designed to assemble.
These continuous developments also enable us stay ahead of the rapidly changing customer manufacturing needs in photonic component assembly.
Multi-DOF precision positioning and alignment
Cutting-edge positioning systems coupled with machine vision
ensure flexibility and reliable high-precision alignment
Accurate, repeatable and reliable positioning of tiny components over millions of cycles is one of the main considerations in the design of our machines. The best mechanical motion stages on the market are complemented with proprietary components to couple precision with industrial-grade robustness. Both conventional stacks of linear translation stages and goniometers, hexapod-like 6-DOF (degrees of freedom) devices, long-travel gantries, as well as SCARA and anthropomorphic robots are routinely integrated in our machines.
State-of-the-art real-time controllers ensure fast interpolation of multi-axis systems with advanced functionalities such as pivot-point-based motion space and fast active alignment.
Multiple camera systems and advanced machine vision algorithms are seamlessly interfaced to motion control to provide guidance, pre-alignment, and other advanced functionalities. The motion-space and vision-space are correlated via automated geometric calibration procedures.
Last but not least, all hardware functions are controlled by ficonTEC’s flexible, modular and easy-to-use process programming software, ProcessControlMaster.
Bonding in Place
Several bonding technologies are available
that ensure reliable performance and long component lifetime
The various bonding approaches – UV and/or thermal-curing epoxy, laser welding, brazing, soldering and reflow processes as well as laser-induced soldering – are extremely critical procedures during micro-assembly. Typical applications include bonding of laser diode chips, photodiodes, micro-optical elements and lenses, optical fibers, LEDs, etc. onto a substrate, a submount, or even onto a full photonics wafer.
An automated approach for the selected type of bonding must provide absolute control over the process, and must thus accomplish several tasks and goals:
- accurate dispensing of different viscosity adhesives for epoxy bonding
- accurate pre-alignment re-positioning following dispensing
- properly distributed/timed UV flashing
- careful aiming and focusing of laser beams for laser welding
- controlled thermal cycles / thermal distribution for soldering and laser-induced soldering
ficonTEC provides an established platform of BondLine die bonder systems for many photonics micro-assembly tasks.
Combining Optical & Electrical Testing
Our testing equipment is focused on automated measurement
and testing of photonics devices from single chips through to wafer level
Some form of testing at ‘single die’ or at ‘packaged device’ level has been often included on ficonTEC manufacturing equipment as a necessary step within an assembly process. As numbers and volumes of photonics manufacturing increase, automated test machines have gained their own space. We also witness a clear trend toward full wafer-level photonics testing. Wafer-level testing with probe cards holding several thousand pins are common in the semiconductor world, with typical contact pads of 80 x 80 µm2. Optical probing, however, requires much higher positional accuracies – in the submicron range – via either vertically accessible grating couplers or via edge coupling, the latter obviously a challenge at wafer level.
As both electrical and optical probing is needed to test photonics devices, some kind of integrated approach is needed, pushing us to the development of combined optical-electrical probe heads.
Common tests include optical power insertion losses, spectral measurements, electrical/optical bandwidth, temperature dependence measurements, and many more. As the number of optical channels for simultaneous testing increases, more demands will be put on to modular instrumentation, including tunable laser sources, multi-channel power meters, optical switches, etc.