The flexibility built into Finetech die bonders is ideal for the variety of process technologies required in optical package assembly. Optical packages are assemblies comprising optical (lenses, prisms, apertures, filters, etc.) and electronic components (LD, PD, amplifiers, controllers, etc.). Applications can be found in communication technologies where optical signals are transformed into electrical signals and vice versa. In order to have a package working properly it is mandatory that the optical and electronic parts are aligned to each other with highest precision. The task becomes even more complex as, by design, these packages typically are actively tempered by thermo-electric coolers (TEC), which need to be integrated into the assembly as well.
To illustrate, a multi-step application of bringing a lense into a TOSA using several bonding technologies (gluing, soldering, thermocompression) is described below.
A lense on a silicon submount is placed into a V groove in a defined distance to the outlet facet of a semiconductor laser. The silicon submount is seated on a TEC and the TEC is integrated into the TOSA. Finally, a flex contact is bonded onto the TOSA insert to connect the circuit to peripheral devices.
What are the Challenges?
- Multiple step task
- Accuracy better than 5 microns
- Sophisticated tooling
- Various lighting and magnification values
- Relative placement
- Different planes of sharpness
- Different processes (gluing, fluxless lead free soldering, thermocompression)
- Different process parameters (temperatures, time, force)
The Finetech Solution
A typical TOSA (Transmitter Optical Sub Assembly) design:
- Hermetic case, ultra compact
- Kovar body with CuW bottom
- Contains LD, monitor PD, electronics, thermo-electric cooler (TEC), filters, lenses
- Fibre connection and lens on front
- Electrical RF connection on back side
- For Ethernet connections up to 100 Gbit/s
- TOSA: Transmitter Optical Subassembly
- ROSA: Receiver Optical Subassembly
Process Step I: Adhesive Application and Defined Lense Placement
Apply Adhesive Into V Groove
- Mix 2 compound epoxy adhesive
- Fill adhesive into tub
- Dip dispensing tool into adhesive
- Align dispensing tool to V groove
- Put down placement arm to dispense adhesive
- Lift placement arm for next process
Place Lens Into V Groove at Defined Position
- Pick up lens from tray in defined orientation
- Align LD beam outlet to lens peak point
- Shift substrate in x, relative to lens
- Place lens into V groove
- Cure adhesive by heat
FINEPLACER® Bonding Systems
Due to the modular design approach, FINEPLACER® bonding systems can be configured for virtually any application challenge.
The main distinguishing features between the machines are the
- degree of automation
- optical resolution and
- placement accuracy
Browse our product range or get in contact with your sales contact to figure out the best equipment solution for your specific application requirements.