Laser bar submounts in W/Cu

Tungsten copper (W/Cu) submounts with pre-deposited AuSn, for mounting of laser diode bars and arrays.


Grade 90/10 (W/Cu)
Thermal conductivity 185 W/mK
CTE 6.4 ppm/°C
Mechanical Dimensions
Min. length and width 1.0 mm x 1.0 mm
Max. length and width 15 x 5 mm
Thickness range 0.25 – 1.5 mm
Typ. High spec.
Length and width ± 0.05 mm ± 0.02 mm
Thickness ± 0.05 mm ± 0.01 mm
Edge chipping < 0.05 mm < 0.02 mm
Flatness 1µm/mm 0.5 µm/mm
Surface finish < 1.0µm Ra < 0.25µm Ra
Critical edge radii < 30µm < 5µm

Sharp edge

The laser bar will usually need to be closely aligned with one edge of the submount. Standard edges are as machined. For critical applications one edge can be made super sharp.

Standard Super sharp
Critical edge radii < 30 µm < 5 µm
Other edges < 50 µm < 50 µm


Various metallisation schemes can be applied. The standard coating is vacuum sputtered Ti/Ni/Pt/Au.

  • Faces: 0.1µm Ti / 2.0µm Ni / 0.2µm Pt / 0.5µm Au
  • Side walls: ~1/3 thickness of faces

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 76 Au/24 Sn, normally at ~3.5 – 5.5 microns thick. The alloy ratio can be tailored for specific applications. The solder layer can also be wrapped over the critical edge to aid solder wetting and minimise solder balling in front of the laser facet.

Patterned AlN and other metal laser mounts

Use the links on the left for details of our capabilities in manufacturing patterned AlN laser mounts together with sharp edge C-mounts, photodiode mounts and other optoelectronic and RF related products.

For further details please contact us.