Aluminum nitride substrate

Overview
This Cu-AlN-Cu three-layer submount functions as a heat sink for high-power laser diode (LD) modules. The Cu/AlN/Cu composite structure provides high thermal conductivity while maintaining electrical insulation. Control of Cu plating and layer thickness enables thermal expansion (CTE) matching with LD chips, supporting higher output power and extended module lifetime. The design does not require pullback on critical edge areas, allowing greater freedom in package and optical designs.

Key features

• Cu + AlN composite provides combined thermal conductivity and electrical insulation
• CTE matching with LD achievable by adjusting Cu and AlN thickness
• Thickness control allows tuning of CTE to suit specific LD materials
• Suitable for multi-emitter LD configurations
• No pullback on critical edge areas
• Facilitates P-side-down LD mounting and compact layouts
• AuSn / AuGe solder vapor deposition available
• Sharp edges enable precise LD alignment
• Edge radius < 20 μm

Comparison data (reference)
Unit / Cu-AlN-Cu / AlN / CuW (10/20)
Material feature / − / Insulation / Conductive
Thermal conductivity (W/m·K) / 190–250※ / 170 / 180/200
CTE (ppm/°C) / 6–10※ / 4.6 / 6.5/8.3
Electric resistance (Ω·m) / − / − / 5.3/4.0 (×10-8)
Work voltage (V) / <200 / <200 / NA
Relative permittivity (@1 MHz) / − / 9 / NA
Dissipation factor (Tan δ) / − / 5×10-4 / NA
(※Controllable by design)

Applications

• Industrial lasers: welding, cutting, marking, surface treatment (annealing), etc.
• Medical lasers: ophthalmology, hair removal, endoscopic laser systems
• Semiconductor equipment: power devices and laser-based processing tools
• Digital equipment: laser printers and multifunction printers

Technical specifications

• Product type: Insulation-type Cu-AlN-Cu three-layer submount (Cu / AlN / Cu)
• Function: Heat sink for high-power LD modules combining thermal conductivity and electrical insulation
• Thermal conductivity: 190–250 W/m·K (Cu-AlN-Cu, controllable by design)
• CTE (coefficient of thermal expansion): 6–10 ppm/°C (controllable by design)
• Electric resistance: not specified for Cu-AlN-Cu (conductive values listed for CuW)
• Work voltage: <200 V
• Relative permittivity (@1 MHz): 9 (reference)
• Dissipation factor (Tan δ): 5×10-4 (reference)
• Soldering: AuSn / AuGe solder vapor deposition available
• Edge quality: Edge radius < 20 μm for precise LD alignment
• Design notes: Control of Cu plating thickness to match LD; pullback not required on critical edge area; adjustable Cu and AlN thickness to tune CTE
• Recommended for: Multi-emitter LD and P-side-down LD configurations