VCSEL & Photo Diode

Packaging of optoelectronic devices is one of the key applications in the division of micro assembly. Densely packed multiplex transmitters, receivers and combined devices are cornerstones of new photonic applications for highest data rates. Bonding these components demands high accuracy alignment in combination with appropriate bonding technologies.

Glue dipping
Bonding of dipped component

What are the Challenges?

Gentle handling of small components and fragile materials
Bonding optically active structures face up or flipped
From single emitters up to 12x arrays
No touch zones
Delicate topography of Laser and PD apertures
Position referencing chip to substrate or chip to chip
PR on active structures to achieve highest accuracy
Apply adhesives with small and stable volumes
Embedded thermal and UV curing
Glue dipping
Bonding of dipped component
Align and bond optical lenses

The Finetech Solution

Bonding of VCSEL+ VCSEL Arrays / Photodiodes + Photodiode Arrays / Lens Arrays

Single and arrayed VCSEL

Finetech's semi and full automated FINEPLACER^® systems offer complete solutions with highly reproducible precision and wide range technology support. One single platform can perform the complete assembly:

Pick up components from different presentations (e.G. GelPak^®)
Dip components into glue or dispense glue on programmed positions
Automated alignment and bonding of various components
Easy to adapt library system for fast process development
Integrated measurement functions to observe bonding results

Up to 0.5 µm Bonding Accuracy + Passive Optical Alignment

Relative alignment
VCSEL and Photo Diode alignment

Active alignment, normally needed in such an application, can be simplified or even avoided by using high accurate optical alignment and placement.

Bonded emitter arrays can be perfectly aligned relative to photodiode arrays to directly match defined parallel links. Lens arrays can additionally be mounted to complete a fiber optic interface.

Extended Field of View + High Magnification

Extended field of view (left)
Extended field of view (right)

Small structures to be recognized require high optical magnifications. Usually, this results in a small field of view, restraining the flexibility of a PR system.

With its fast and high precision optics movement, the FINEPLACER^® enlarges its field of view without compromising accuracy.

Thus, large components and substrates can be captured and observed with the same quality as tiny ones. For VCSEL and PD arrays with dimensions of 200 µm x 3000 µm and more but active structures below 5 µm this benefit can be important.

Integrated Process Management (IPM)

Integrated Process Management (IPM)
Principle of process gas integration
Operating software for bonding

The Integrated Process Management (IPM) is the center piece of a FINEPLACER^® system¹ - the place where it all comes together. IPM is more than just thermal management. It synchronizes the control of all process modules and their related parameters:

Controlled and precisely balanced interaction of top and bottom (pre-)heating and cooling
Control of temperature, time, force, power, energy, flow
Controlled process gas integration for reduced solder contamination, minimized surface tension effects and smooth spherical solder residues

IPM is very complex, yet easy to access. Via the GUI of the operating software, the user has perfect control of all required adjustments. Just drag 'n drop to define temperature ramps or activate process modules. All settings are represented in only one profile, making for a very intuitive work flow.

The operating software provides an ever-growing library of profiles for all kinds of processes. It also offers comprehensive data logging functions essential for statistical process control.

In combination with the system-to-system process transfer capability this is as easy as process development can get.

¹ _{FINEPLACER^® core offers co-ordinated top and bottom heating but does not support IPM}