Glossary

A lead-free solder composed of tin (Sn), silver (Ag), and copper (Cu).

A type of steel alloy that is resistant to corrosion and staining.

A hermetic sealing method in which a lid is placed on a package with a seal ring and an electrical current is applied through roller electrodes to weld the lid. While the weld area reaches high temperatures, the temperature of the devices mounted inside the package remains low.

The shape of solder formed between a printed circuit board (PCB) and an external terminal of a solder-mounted component (see diagram below). In LCC and SMD packages, the solder flows to a metallized castellation, forming a fillet. This enhances mounting strength and enables easier visual inspection of the soldering condition.

The process of mounting components onto a PCB using solder.

An insulating substrate that houses devices such as lasers and LEDs. These devices are mounted on the substrate and tested before being integrated into a package or module. Essential requirements of an optical sub-mount include flatness, heat dissipation, and electrical routing.

A solid-state device that uses the Peltier effect to transfer heat by applying and adjusting electrical current. Used in cooling applications, including temperature control for laser diodes.

A measure of resistance against thermal transfer. A lower value indicates more efficient heat transfer capability (unit: K/W).
The thermal resistance values on this site are calculated using the simplified formula below.