In 2017, the appearance of iPhone x made the 3D sensing technology providing face unlocking popular in the industry, and also made the core semiconductor laser VCSEL in the 3D sensing module repeatedly mentioned by the industry. Recently, in the product trend forecast of the new iPhone in 2020, some industry experts once again said that it is expected that the three new iPhones in the second half of 2020 will be equipped with front 3D cameras, of which two new opportunities will be equipped with rear TOF and front and rear VCSELs.

The expert also predicted that the shipments of mobile phones equipped with VCSELs before and after, including the iPhone, will increase significantly by 450% – 500% in 2020, and the number will increase to 75 million to 80 million.

In addition, according to the latest infrared sensing market report of LED inside of Jibang consulting, when the overall shipment of smart phones is expected to decline in 2019, mobile phone brand manufacturers offer a specification competition for the flagship in the second half of the year, 3D sensing module has become one of the important equipment, and VCSEL has been regarded as its official standard in future models. Driven by this trend, it is estimated that the market output value of VCSEL in mobile 3D sensing is expected to increase to US $1139 million in 2019.

With the maturity of VCSEL technology, the optical sensing technology with VCSEL as the core component has entered the industry level application. At the same time, it has been explored in the fields of laser printer, optical mouse, automotive lidar, assisted driving, gas sensor, living body detection, iris recognition, AR / VR, machine human vision, medical beauty and so on, and the upstream and downstream of the industry have benefited one after another. Some investment institutions predict that the VCSEL market is expected to increase from US $330 million in 2017 to US $3.5 billion in 2023, with a compound annual growth rate of 48%.

In fact, although the business opportunities of VCSEL are unanimously favored by all walks of life, there are very few domestic energy VCSELs. The technical bottleneck is high, the demand for chip design capability is high, and the development speed of domestic VCSEL is far lower than expected due to high costs, patent barriers and other factors. Although some domestic chip design manufacturers are involved, their technical strength is relatively backward, and the yield and reliability are insufficient, so it is difficult to get rid of their dependence on foreign mature suppliers. In addition, in more practical applications, what customers need is a simple and easy-to-use light source scheme with overall optimization of light and electric heating (packaged optical chip and assembled optical lens), rather than a separate VCSEL optical chip. At present, few companies can provide complete light source solutions, which largely limits the penetration speed of VCSEL technology at the application end.

Recently, Ruishi technology, which focuses on the field of semiconductor optics, has released a full range of high-performance VCSEL products independently developed, which is expected to greatly improve the ease of use of VCSEL technology and accelerate the penetration of VCSEL in a variety of application fields. Ruizhi technology has broken through the whole chain of “chip + packaging + optical integration”, mastered the key technologies such as completely independent chip design and optical integration optimization, and has dozens of technical invention patents at home and abroad. At the end of 2018, Ruizhi technology released the VCSEL TOF module with “high core proportion” for the first time, and independently created “1.5 times optical integration technology” relying on the team , fray series LED floodlight products specially for 3D sensing applications have been developed.

It is understood that the VCSEL light source module products released by Ruizhi this time are mainly divided into two series, tray series products with diffuser component package and Vray series products directly packaged by VCSEL chip (Figure 1). The optical power of the product ranges from 5MW to 5W. In addition to 850nm and 940nm, 808nm and 795nm are also configured for customers to choose. The product size is pin to pin with the current general size in the industry, and the product has strong applicability. At the same time, the luminous angle of the product also has a variety of specifications, which can meet the needs of most customer application scenarios.

Figure 1: Ruizhi VCSEL product matrix

In addition to complete specifications, Ruizhi VCSEL light source module products are at the leading level in the industry in terms of performance and reliability. According to the person in charge of Ruizhi technology products, the photoelectric conversion efficiency (PCE) of Ruizhi’s mass-produced VCSEL chip has exceeded 45%, and the photoelectric conversion efficiency of encapsulated light source products has exceeded 40%. In terms of product reliability, Ruizhi technology fully considers the thermal stability and structural stability, adopts aluminum nitride ceramic substrate with high thermal conductivity, and optimizes the packaging process according to the high heat density characteristics of VCSEL, which can ensure the high-efficiency export of chip heat and improve the long-term working reliability of the product. At the same time, because the substrates used by Ruizhi products are all integrated supports, the support and the bottom ceramic substrate are integrated, and the structure is stable, eliminating the risk of peeling off the support and the bottom ceramic substrate.

Figure 2. Physical drawing of Ruizhi VCSEL products: tray (left), Vray lens (middle), Vray flat (right)

It is worth mentioning that the core component VCSEL chip used in the series of VCSEL light source products released by Ruizhi this time is a product independently developed and produced by the team, with complete intellectual property rights and performance reaching the industry-leading level. Ruizhi technology has successfully developed a full range of VCSEL chip products. The product series covers different wavelengths, including 850nm and 940nm. The optical power ranges from a few milliwatts to a few watts (see Figure 3). The application scenarios range from 3D structured light to proximity sensing, infrared floodlight and 3D TOF sensing.

Figure 3: physical drawing of Ruizhi VCSEL chip product series

According to Dr. he Yongxiang, head of chip products of Ruizhi technology, in order to meet the requirements of application end for chip performance, Ruizhi team has developed photoelectric conversion efficiency (PCE) up to 52% after several rounds of optimization of material design and processing technology, including doping of distributed Bragg reflector in epitaxial material and optimization of fine structure design of adjacent quantum well active region Industry leading VCSEL epitaxial material. Based on top performance epitaxial materials, the performance of Ruizhi VCSEL chip series products has fully reached the industry-leading level. Taking the 3W regular array VCSEL chip that can be used for 3D TOF as an example, the photoelectric conversion efficiency (PCE) can be as high as 45%, the performance is evenly distributed on 6-inch wafers, almost all chips have conversion efficiency of 40% or more, and the key photoelectric performance is quite stable in the temperature range of 25 ℃ to 50 ℃. While pursuing the excellent performance of VCSEL chip, Ruizhi always integrates the optimization of reliability into the design of epitaxial materials and manufacturing process. There is no obvious deterioration in the completed reliability tests such as accelerated aging, high temperature and high humidity of VCSEL chip, and the equivalent life is more than 10 years under normal service conditions.

Figure 4: PCE distribution diagram (left) and product photoelectric curve (right) of 6-inch wafer mass production of Ruizhi technology VCSEL chip

Ruizhi technology team has rich experience in VCSEL chip mass production supply chain integration. At present, it has completed the integration of local supply chains with industry-class capabilities such as epitaxial growth, wafer manufacturing, chip performance testing and reliability verification, so as to provide a strong guarantee for chip mass production, quality control and mass production yield. At the same time, in order to ensure the mass production quality of Ruizhi VCSEL light source module, Ruizhi technology built its own chip packaging production line at the beginning of its establishment, has passed ISO9001 quality system certification, and is equipped with professional mass production detection equipment of VCSEL light source, so as to realize the independent control of product mass production quality and supply chain management.

In order to better serve various application needs of customers in different scenarios and accelerate the application of VCSEL technology, Ruizhi has established a complete and fast response customized service mechanism. Customers can customize the size, wavelength, packaging form, luminous angle and optical power of light source products according to their needs. In terms of diffuser customization, Ruizhi cooperates with viavi to jointly provide customized services for customers. Mr. Sinclair VASs, vice president of global marketing and sales of viavi, said: “we are very willing to make more attempts in the field of diffuser application with Ruizhi, and realize more challenging applications through viavi’s professional diffuser design and Ruizhi’s industry-leading VCSEL technology”.

“We are committed to breaking the monopoly competition pattern of foreign manufacturers in the core semiconductor optical device industry and contributing to the innovation and development of China’s industry.” Dr. Wang Yang, CEO of Ruizhi technology, said in an interview, “optics + artificial intelligence” As the core of the fourth industrial revolution, optical sensors are the main source of artificial intelligence data. We are entering the era of consuming photons. As an innovator and promoter in the field of consuming photons, Ruishi technology adheres to the spirit of craftsmanship, pursues the ultimate process and product reliability, and strives to bring advanced optical technology into everyone’s life. With With the three core technologies of “chip + packaging + optical integration”, Ruishi technology will provide customers with truly easy-to-use, cheap and mass-produced semiconductor light source products and optical solutions.

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