High Speed Data Rate Transmission Lines/Laser Diode Submounts (Au/Sn)

Laser Diode Submount (Larger view)

Applied Thin-Film Products (ATP) is one of the industry leaders for Laser Diode Submounts and High Speed Data Rate Transmission Lines for 10 and 40 gigabit applications. ATP custom fabricates thin-film submounts and coplanar circuits for multiplexing. ATP inventories a wide selection of tightly controlled material thicknesses for your laser diode alignment needs. Including high thermal conductivity materials such as Aluminum Nitride, Beryllium Oxide and low loss material such as Fused Silica Quartz and Sapphire. These submounts can include predeposited and patterned Gold Tin (Au/Sn) to accommodate low cost, high volume, automated assembly of laser diode modules. The use of predeposited and patterned Au/Sn replaces the more traditional approach of using Au/Sn Preforms. ATP’s Standard alloy composition is 80% Au and 20% Sn and reflows at 280°C. ATP’s in house capabilities include two state of the art multiple head CO2 lasers for manufacturing complex coplanar structures. ATP offers integrated resistors to transform from 50 Ohms to 25 Ohms and solid filled vias for the toughest thermal applications.

High Speed Data Rate Transmission Lines (Larger view)

Replaces Traditional Au/Sn Preforms

Accurately Controlled Thickness

Lot to Lot Consistency

Reduce Au/Sn Thickness

Homogeneous 80% Au/20% Sn

Complex Solder Pad Geometries

Accurate Laser Alignment

Substrate Material

Aluminum Nitride (AlN):

170 W/mk Thermal Conductivity

200 W/mk Thermal Conductivity

< 2µ" (50nm) surface finish

Beryllium Oxide (BeO):

270 W/mk Thermal Conductivity

2µ"–4µ" (50nm–100nm) surface finish

Alumina Oxide (AL203):

26.9 W/mk Thermal Conductivity

< 1µ" to 3µ" (< 25nm–75nm) surface finish

Metalizations

TiW/Au: 400–1,000Å (40nm–100nm)/100µ" (2.5 microns) min.

TiW/Ni/Au: 400–1,000Å (40nm–100nm)/1,000-2,000Å (100nm–300nm)/100µ" (2.5 microns) min.

TiW/Pd/Au: 400–1,000Å (40nm–100nm)/1,000-2,000Å (100nm–300nm)/100µ" (2.5 microns) min.

Pre-deposited and Patterned Au/Sn Guidelines

Smallest Feature Size: 0.002" x 0.002" (0.078mm x 0.078 mm)

Minimum Pitch ( minimum space between Au/Sn Pads): 0.002" (0.078mm)

Maximum Au/Sn Thickness: 400µ" (10 microns)

Typical Au/Sn Thickness: 160–200µ" (4–6 microns)

Minimum Au/Sn Thickness: 80µ" (2 microns)

Tolerance on Thickness of Au/Sn: ±80µ" (± 2 microns)

Placement Accuracy of Au/Sn: ± 0.0005" (±0.0127mm)

Dimensional Tolerance on Au/Sn Pad: ± 0.0002" (±0.005mm)

Minimum Pull Back from Laser cut edge: 0.005" (0.127mm)

Minimum Pull Back From Conductive Plated Thru Via Holes: 0.005" (0.127mm)