Thin-film Submount

Able to respond a consistent order Realizing film mount to the three-dimension Meet the request through a wide range of technology

Growing demand for submount Meeting needs through a wide range of knowledge and technology

Thin-film submount is used in optical communication equipments that receive light and convert it into electric signal. We have developed the AuSn solder which mounts high-power semiconductor laser diode used for DVD, for instance, and started to manufucture the high heat dissipation aluminum nitride submount. As we have a wide range of technologies, from film mount to submount processing, we can meet various needs from customers.

Thin-film Submount


Submounts for mounting laser diode (LD) elements

Submounts for mounting photodiode (PD) elements

Our technology

By applying membrane technology and thin-film process technology which are learnt through production of the thin-film magnetic head (HDD) and the optical pickup parts, we can form various thin-film functional elements of thin-film electrode, thin-film resistor, thin-film solder, insulating film, film for anti-overflow soldering, and thin-film condenser with high precise fine circuit pattern depending on material of the substrate. In addition, as for substrate geometry, fine pattern formation to not only plane surface but also to the three-dimension (from 1- 4 aspects) is available.

Technical information

Characteristics (Attributes) of submount

Submount, the module for optical device (optical pickup for DVD/CD recorder, optical communication), has the structure whereon the semiconductor laser diode (LD) and the semiconductor photodiode (PD) are mounted directly.

In general, the structure of submount for LD consists of materials including thin-film electrode pattern, thin-film resistance and metal thin-film solder for LD tip based on the ceramic substrate, which has superior thermal conductivity and heart radiation. Also the submount has the shock-absorbing function that eases the damage occured from coefficient of thermal expansion difference between core stem and LD. For the submount for PD, circuit pattern is formed on the substrate base which is superior in insulated function, such as alumina.

Due to rapid progress and diffusion of computers and audio equipments in recent days, heat radiation is a critical issue in dealing with high-output devices, such as communication traffic with larger capacity and optical media with faster writing speed. Therefore, demand of submount will continue to increase.

Specification in details

Substrate material Item Specification
AlN Thermal conductivity ≧170,200,230 W/mk
Stock thickness & Tolerance 0.1~3.0mm,±0.02mm
Al2O3 Purity ≧90,96,99.5%
Stock thickness & Tolerance 0.2~5.0mm,±0.02mm
Electrode & Conductor Film constitution Au/Pt/Ti,Au/Ni/Ti,Au/Cr,Al/Ti etc.
Correspondence film thickness & Tolerance 0.01~8μm ±20%
L/S ≧5μm/5μm
Resistor Material Ta2N
Tolerance ±5%
Temperature coefficient 0~-100ppm/ºC
Solder Material AuSn20,AuSn30,Ag/Sn,Sn
Correspondence film thickness & Tolerance 2~5μm ±15%
Isolation Material SiO2
Isolation ≧100MΩ (100V impression)
Pattern form Formation method Dry Wet Lift-Off
Dimensional tolerance ±5μ ±25μ ±10μ
Front and back ±10μ
Processing Cutting Full cutting,Half cutting
Polishing Ra≦0.05μm