VCSEL has a broad application space and rapid development in 3D facial recognition, augmented reality, automotive cabin sensing as well as self-driving cars (e.g. LIDAR) and machine vision, etc. It is also one of the hot applications of DPC ceramic substrates.
I. What is a VCSEL laser?
VCSEL laser is the abbreviation of Vertical Cavity Surface Emitting Laser (VCSEL), a semiconductor-based laser diode that emits a highly efficient beam of light vertically from its top surface.In 1977, a research group led by Prof. Kenichi Iga of Tokyo Institute of Technology first proposed the fabrication of a vertical cavity surface emitting laser (VCSEL). In 1977, a research group led by Professor Kenichi Iga at Tokyo Institute of Technology first proposed the idea of manufacturing a vertical cavity surface emitting laser (VCSEL), and in 1979, the first VCSEL laser that could be operated pulsed at a temperature of 77 K was realized.
The VCSEL laser consists of a distributed Bragg reflector (DBR) at the top and bottom, and a light-emitting zone structure in the center.
VCSELs offer several advantages over other types of lasers, including:
1. Ease of fabrication and integration: VCSELs are relatively simple to fabricate using standard semiconductor processes and can be integrated with other electronic components to form highly integrated systems.
2. High efficiency: VCSEL's high electric-optical conversion efficiency enables it to achieve high light output at low power, such as for optical communications, optical storage and other fields.
3. High speed: VCSELs can reach speeds of several gigabits per second (Gbps), making them suitable for high-speed data transmission.
4. Narrow beam: VCSEL's beam is very narrow, enabling better focusing and positioning, suitable for LIDAR, optical communications and other fields.
5. Long life: VCSELs have a long life and can maintain a stable output over a long period of time.
6. Low cost: VCSEL's relatively low manufacturing cost allows for mass production and is suitable for large-scale applications.
VCSEL has advantages in manufacturing cost, power conversion efficiency, speed, integration, etc., so it is widely used in optical communications, optical storage, LIDAR, biomedical and other fields. According to Yole Research, the global VCSEL market will grow from USD 1.2 billion in 2021 to USD 2.4 billion by 2026, at a CAGR of 13.6% during the period.
Second, why VCSEL with DPC substrate
DPC ceramic substrate has many characteristics such as high thermal conductivity, high insulation, high line accuracy, high surface flatness and thermal expansion coefficient matched with the chip, and can be vertically interconnected, etc., which greatly meets the encapsulation requirements of VCSELs, and has a wide range of prospects in the application of VCSELs.
1. Good heat dissipation
VCSEL chip conversion efficiency is low leading to serious heat dissipation problems, DPC substrate vertical interconnection, the formation of internal independent conductive channel, the ceramic itself is both an insulator, but also heat dissipation, to achieve thermoelectric separation.
2. High reliability
VCSEL chip power density is very high, need to consider the chip and substrate thermal expansion mismatch caused by the stress problem, and ceramic substrate with VCSEL high matching thermal expansion coefficient. In addition, DPC ceramic substrate can realize the metal frame and ceramic substrate of one-piece molding, tightly integrated, avoiding the post assembly process of additional paste process, alignment accuracy and other issues, as well as the reliability of the glue aging problems.
3. Vertical Interconnection
VCSEL packages need to be set up to the lens above the chip, that is, the substrate needs to be made into a three-dimensional chamber, DPC substrate has a highly reliable vertical interconnect advantages for vertical eutectic welding.
