What is COC technology?
COC technology is a packaging technology that directly attaches chips to a carrier, also known as a packaging substrate or packaging carrier board. It can be a certain ceramic material or special plastic. It is a bridge between bare chips and external circuits, and an important component of optoelectronic ICs.
The middle part of the picture shows the CHIP (bare chip) of SOA, which is fixed on a ceramic substrate (carrier) using special adhesive or eutectic technology. The gray part in the figure. Coat the empty part of the carrier with a metal thin film, as shown in the golden yellow part at corner 4 of the figure. By threading a gold wire between the electrode of CHIP and the metal film, the metal film becomes a relay island for circuit connection. This creates a COC shaped SOA. SOA in COC form has a small volume, light weight, and is easy to package later. Or provide other optical device manufacturers with their own application and design ideas, and package them with other micro active and passive optoelectronic devices to form new photonic integrated circuits. This can significantly reduce the packaging difficulty and cost for optical device manufacturers, shorten the development cycle of new products, and effectively improve the integration and reliability of optoelectronic devices. COC technology is widely used in fields such as microwave and radio frequency, optoelectronics, and sensors, and is an important packaging technology.
As for why SOA needs to have a supply form like COC, it is determined by the characteristics of optoelectronic semiconductors and packaging processes. Pure electric semiconductors, with only the flow of electrons, can be made very small with a diode or transistor, and billions of chips can be made on a CHIP, such as our common IC integrated circuits such as CPUs and memory. But optoelectronic semiconductor chips are different. In addition to electrons, they also have photon motion inside. In order to generate more photons, the volume of optoelectronic semiconductor diodes is often made larger. And the doping elements of optoelectronic chips with different functions are different, and the internal structure differences are also significant. In this way, optoelectronic chips often appear as independent entities. In order to connect the optical paths of active or passive optical devices with different characteristics, the chip needs to be lifted to a certain height, which is provided by the carrier in COC. In this way, COC has become a form of supply for optoelectronic semiconductors such as SOA.
