Growing demand for submount Meeting needs through a wide range of knowledge and technology
Submounts for mounting laser diode (LD) elements
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.
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
|AlN||Thermal conductivity||≧170,200,230 W/mk|
|Stock thickness & Tolerance||0.1~3.0mm,±0.02mm|
|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%|
|Correspondence film thickness & Tolerance||2~5μm ±15%|
|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|