Miniature laser diode submounts
Miniature thin film metallised aluminium nitride submounts with pre-deposited AuSn, for mounting of laser diodes and LEDs.
Material
| Grade | 170* | 200 |
|---|---|---|
| TC W/mK | ~170 | ~200 |
| CTE ppm/°C | ~4.6 | ~4.6 |
| Surface finish | ~0.15μm Ra | ~0.15μm Ra |
| Thickness range | 0.25 – 1.5 mm | 0.25 – 1.5 mm |
| Mechanical dimensions | ||
| Min. length and width | 0.5 mm x 0.5 mm | 0.5 mm x 0.5 mm |
| Max. length and width | 75 x 75 mm | 75 x 75 mm |
| Tolerances | ||
| Typical | High spec. | |
| Length and width | ± 0.05 mm | ± 0.02 mm |
| Edge chipping | < 0.05 mm | < 0.01 mm |
*standard material.
Conducting or insulating
The AlN mounts can be metallised with the option of making the mount conducting or
insulating. For conductive AlN, metallisation is deposited onto at least two of the side walls as
well as the top and bottom surfaces. The thickness of the side wall metallisation is tailored
depending on the electrical load to be carried.
Metallisations
Various metallisation schemes can be applied, the standard is Ti/Cu/Pt/Au.
Soldering only required 0.1Ti / 1.0Cu / 1.0Pt / 0.1Au Au wire bonding required 0.1Ti / 1.0Cu / 1.0Pt / 0.5Au.
The Au, Pt and Cu layer thicknesses depend on the application. The copper is primarily used to provide the electrical conductivity on the sidewalls and is nominally 1 μm thick on the faces and a total of 0.6 μm thick on the walls. To ensure the copper is properly covered the platinum barrier layer is usually also specified at 1μm on the faces. Generally for gold wire bonding 0.5μm minimum of gold is required. A standard specification for the top and bottom faces would be:
Pre-deposited AuSn
A thin layer of vacuum deposited AuSn can be applied over one or both of the top and bottom faces. The standard alloy ratio is nominally 76Au / 24Sn, normally at ~3.5 – 5.5 microns thick. The alloy ratio can also be tailored for specific applications.
Patterned AlN and metal laser mounts
Use the links on the left for details of our comprehensive capabilities in manufacturing patterned AlN laser mounts together with sharp edge C-mounts, laser bar mounts, photodiode mounts and other optoelectronic and RF related products.
For further details please contact us.