The Mechatronic Technology Used for Photonics Testing & Assembly

Highly-modular, flexible and fully-integrated mechatronic technology controlled by powerful software tools.

Photonic devices for high-tech applications are becoming ever more complex. Ever increasing numbers of optical elements that have diverse photonic properties need to be integrated into ever smaller packages.

ficonTEC machines fulfill the definition of state-of-the-art mechatronics and encompass fully advanced mechanical positioning/motion elements, instrumentation and electronics, combined with powerful software tools.

Several highly-modular, well-established and fully-integration-capable product lines have been developed as a result of the accumulated experience of hundreds of installed base machines and continued machine development. This results in increasing levels of reproducibility and performance and, consequently, lower cost-per-part and higher yield of the devices our machines are designed to assemble.

Due to these continuous developments, we are able to stay ahead of the customer manufacturing needs in photonic component assembly, which change rapidly.

Multi-DOF Precision Positioning and Alignment

Cutting-edge positioning systems combined with machine vision ensure flexibility and reliable high-precision alignment.

One of the main considerations in the design of the machines is accurate, repeatable and reliable positioning of tiny components over millions of cycles. The best mechanical motion stages available on the market are complemented with proprietary components to combine industrial-grade robustness with precision.

The machines from ficonTEC are routinely integrated with stacks of linear translation stages and goniometers, long-travel gantries, hexapod-like 6-DOF (degrees of freedom) devices, and also SCARA and anthropomorphic robots.

Real-time state-of-the-art controllers allow for fast positioning interpolation for multi-axis systems with advanced functionalities, for example pivot-point-based motion space and fast active alignment.

Advance machine vision algorithms and multiple camera systems are seamlessly interfaced to motion control, which provides guidance and pre-alignment as well as other advanced functionalities. The vision-space and motion-space are correlated using automated geometric calibration procedures.

Finally, ficonTEC’s modular, flexible and easy-to-use process programming software, ProcessControlMaster, is used to control all hardware functions.

Bonding in Place

A variety of bonding technologies are available to ensure long component lifetime and reliable performance.

The bonding approaches are critical procedures during micro-assembly and include: laser welding, UV and/or thermal-curing epoxy, soldering and reflow processes as well as laser-induced soldering. Typical applications include bonding of photodiodes, laser diode chips, optical fibers, LEDS, micro-optical elements and lenses, etc. onto a submount, a substrate or even onto a full photonics wafer.

An automated approach to selecting the type of bonding needs to provide complete control over the process and so must accomplish several goals and tasks:

• Controlled thermal cycles/thermal distribution for soldering and laser-induced soldering
• Careful aiming and focusing of laser beams for laser welding
• Accurate dispensing of different viscosity adhesives for epoxy bonding
  • Properly distributed/timed UV flashing
  • Accurate pre-alignment re-positioning following dispensing

Several well-established die bonder systems for many photonics micro-assembly tasks are provided by ficonTEC.

Welding

Soldering

UV epoxy bonding

Combining Optical and Electrical Testing

ficonTEC testing equipment is focused on automated measurement and testing of photonic devices from single chips all the way through to wafer level.

Often, some form of testing at ‘packaged device’ or ‘single die’ level has been included on ficonTEC manufacturing equipment as a step that is necessary within an assembly process. Automated testing machines have gained their own space as volumes in photonics manufacturing increase.

A clear trend toward full wafer-level photonics testing can also be seen. Wafer-level testing with probe cards holding several thousand pins are common within the semiconductor world, with typical contact pads of 80 x 80 µm². However, optical probing requires much higher positional accuracies in the submicron range and utilizes either edge coupling or vertically accessible grating couplers (the former is much more challenging at wafer-level).

Since both optical and electrical probing is required to test photonic devices, some form of integrated approach is needed. This has resulted in the development of combined optical-electrical probe heads. Common tests include spectral measurements, optical power insertion losses, temperature dependence measurements, electrical/optical bandwidth, and many more.

More demands will be put on to modular instrumentation as the number of optical channels for simultaneous testing increases, including multi-channel power meters, optical switches, tunable laser sources, etc.

Automated testing sequences and testing protocols can also benefit from our configurable ProcessControlMaster software. Direct interfacing of process tracking data to an SQL database provides the user with access to statistical analysis of the data, such as a tool for improving production yield.

This information has been sourced, reviewed and adapted from materials provided by ficonTEC Service GmbH.

For more information on this source, please visit ficonTEC Service GmbH.