SILINA, a deep tech startup to curve CMOS Image Sensors at industrial scale – An interview by Yole Développement

The CMOS Image Sensor (CIS) industry has reached ever higher in 2020, reaching the $20B revenue milestone. It has been pushed by a combination of high demand and high prices due to capacity limitations, despite a slow-down in smartphone sales, as thoroughly described in Yole Développement’s report “Status of CMOS Image Sensor Industry 2020”. Yole Développement (Yole) is looking further ahead, trying to identify newer application and technology trends that seem to be around the corner.

After interviewing a world-renowned research institute a few months ago, Dr. Zine Bouhamri, Team Lead Analyst Imaging & Display at Yole Développement sat down with Michael Bailly, CEO of SILINA, a new deep tech startup that focuses on providing a way towards curved CISs. This idea has been around for some time. With SILINA on the path towards industrialization, we address their approach to innovation, targeted applications, roadmaps, and partnerships.

Michael Bailly (MB): My name is Michael Bailly, CEO of SILINA. SILINA is a B2B microelectronics deep tech startup about to bring a paradigm shift to the imaging industry by curving existing imaging sensors at industrial scale.

In 2020, I joined the Entrepreneur First incubation program based at Station F, in Paris, France. There I met my co-founder and CTO, Wilfried Jahn the inventor of SILINA’s unique technology. He has been developing and optimizing SILINA’s unique patented curving process for the past few years.

We offer Original Equipment Manufacturers (OEMs), optical designers, camera integrators and sensor manufacturers our services to help them make the best cameras, improving performance while reducing the overall cost. Our offering has two components. We support our customers in optical system design to find the best options regarding our capability to curve imaging sensors. We offer a service to curve imaging sensors for their manufacturers. Our curving process adapts to various types of sensors, including CMOS, Charge Coupled Devices (CCDs), and Front- and Back-Side Illuminated, to various spectral bandwidths, from ultraviolet (UV) to visible and infrared. It works at various scales, including single-chip, multi-chip and wafer-level. Various shapes can be obtained, including spherical, aspherical, freeform, and custom shapes on demand.

After several years setting up international projects in long cycle technological industries, SILINA is our new challenge. We want to bring this amazing technology to market at large scale.

MB: In Nature, most vision systems use curved retinas, like human eyes. Curved retinas offer a wide field of view for an outstanding image quality with only one lens, the crystalline, making the eyes very compact. Unfortunately, all electronic imaging systems use flat imaging sensors. Flat sensors make the lens very complex, using many expensive optical elements. This degrades the optical performance and capabilities of the camera, and increases the mass/volume budget and overall cost of any camera and optical system.

MB: Curved imaging sensors are the next major innovation for the imaging industry, bringing a real paradigm shift in the way we design vision systems. They overcome hardware limitations that no software can solve, and enable a whole new generation of cameras. They bring drastic improvements on four key criteria: increased image quality and detection capability, and reduced cost and bulk of cameras.

SILINA has developed a unique innovative process which enables to curve the existing imaging sensors at scale. This patented innovation stems from the cross-pollination of several professional experiences and fields of expertise. It solves a difficult technological problem and makes the curving process repeatable and scalable. First, a pre-processing step makes the sensor flexible and guarantees its good performance. Then, we use specific equipment to curve the sensors, for which we can monitor all the parameters to ensure the process is repeatable and accurate.

In addition, SILINA’s curved sensors can be integrated into the same original packaging as has been developed for traditional flat sensors. This means that the mechanical mount, electronic board and the overall packaging remain the same. It facilitates the integration of the technology into existing production lines. Finally, we curve sensors reliably and at industrial scale for the very first time. We have recently made a demonstrator and curved all the sensors of a single wafer, demonstrating the scalability, repeatability and high yield of our technology.

Finally, we curve sensors reliably and at industrial scale for the very first time. We have recently made a demonstrator and curved all the sensors on a single wafer. A set of 275 curved sensors has been curved at the same time, in less than one hour. This demonstrates the scalability, repeatability and high yield of our technology. These sensors are 1 inch format, like the ones planned to be used in the new generation of smartphone cameras. Smaller and larger formats can also be curved in the same way. Also, we have manufactured a curved sensor with a freeform shape, which is a very complex shape to optimize even more the performance and compactness of imaging systems we have designed for one of our targeted markets. R&D developments are on-going and new patents are being filed.

To be clear, SILINA does not design nor manufacture imaging sensors. It operates as a B2B service company for small volume applications of several thousand sensors a year, to curve and pre-package existing sensors coming from sensor manufacturers. For high volume applications, SILINA will propose intellectual property (IP) licensing deals with its partners.

MB: Curved sensors provide several technical and economic benefits. The value proposition varies from an application to another, strictly depending on the characteristics of optical systems.

The benefits that have been demonstrated in various optical designs include improved image quality and sensitivity. We can offer contrast and sharpness up to 5x better at the image edge for a sharper image with better resolution. We produce a faster lens with higher signal to noise ratio, lower integration time and sharper depth of field. Light transmission is up to 3x better, offering higher performance in low light and again higher signal to noise ratio. Chromatic aberration is reduced by up to 50% for better color rendering and color fidelity. Increased camera field of view improves detection capabilities. Removing vignetting provides better illumination uniformity and better performance in low light.

We also reduce the mass/volume budget. There is up to 50% reduction in the number of optical elements such as lenses and mirrors. The end product is up to 6x lighter and more compact.

Finally we reduce costs. There are fewer and simpler optical elements to manufacture. This releases constraints in optomechanical tolerancing. It makes metrology faster. It also enables faster and easier assembly, integration and alignment.

MB: SILINA offers its services to the imaging sensors market. The CMOS Image Sensor market is growing from being worth $19.3 billion in 2019. The growth is mainly driven by smartphones, automotive and security. We group the various market segments in three tiers. The first would be the very high-end market comprised of aerospace, defense and medical imaging. The second would be including the industrial imaging, consumer, security and automotive markets. The third one, representing close to 70% of market value, is the smartphone market.

MB: The main value proposition is specific to each market segment and application, high image quality for smartphones, low mass/volume budget for aerospace and drones, better detection capability for automotive, for example. These needs drive our technological developments in several complementary aspects including yield of production, shape accuracy and resistance to environmental constraints. In the end, each technological development for a specific application benefits the others.

Let me go deeper in three specific examples. One of the main differentiators in the smartphone industry is camera imaging quality. Smartphone companies can’t continue multiplying the number of cameras to mimic a zoom effect. Curved sensors can solve that. Also, the thickness of a smartphone is mainly limited by the height of the camera module, with reference to the optical format of the image sensor. Thanks to curved sensor technology it is possible to reduce the number of lenses inside the camera module and therefore increase the resolution of the image sensor for a given form factor. Use of curved sensors not only improves the camera module design and image quality but also reduces the image signal processing complexity inside the application processor because the signals coming out of the module are less distorted. The benefit will therefore be at two levels: image quality and lower power computation and consumption.

Camera weight is an extremely sensitive parameter for flying systems. In aerospace, the weight of satellites limits the number of embedded scientific instruments for the study of climate change, deforestation, sea level rising, or natural disasters for example. Curved sensor technology enables designers to lower the weight and volume of instruments, giving the possibility to embed even more instruments in the payload. It also increases the detection capability by enlarging the field of view, which shortens the revisit period. For drones, reducing the number of optical elements for a given performance will reduce the weight of the system and will increase the flying time for the same battery size or reduce the battery weight and cost to maintain the same flying time.

The last example is autonomous vehicles and LiDAR. They are facing detection and safety issues, notably due to numerous distorted images acquired by poor camera performance. They also suffer from heavy use of image processing algorithms. By providing a larger field of view and less distorted images, curved sensors enable faster and more efficient data processing to detect nearby objects, increasing the detection efficiency and overall safety.

We have initiated partnerships with OEMs in these three domains to solve these issues.

MB: The OEM is the decision maker in the design of a camera, and SILINA can support this design phase. Once the specifications of the lens design and the sensor shape are validated, SILINA will work closely with the sensor manufacturer to curve its sensors.

To summarize, SILINA offers its optical design service at the very beginning of a camera design phase on one hand, and inserts its curved sensor process in the value chain between the sensor manufacturer and the Outsourced Semiconductor Assembly and Test (OSAT) company on the other hand.

SILINA is creating a new market within the $19.3B CIS market by offering a custom design and curving service, charging a fee per curved sensor by operating as a B2B service company for low volumes. For the scaling of the technology to higher volume markets, we will operate via IP licensing. 

MB: SILINA offers a service to curve existing image sensors from current manufacturers and does not manufacture its own imaging sensors. So SILINA does not compete with any sensor manufacturers. Instead, we are partners and we bring them a competitive advantage to deliver a curved version of their imaging sensors to their customers which constantly want smaller, lighter, and more efficient cameras.

MB: Today, we have initiated partnerships with various players, OEMs, sensor manufacturers, lens manufacturers, camera integrators and packaging houses. Commercialization of our design and curving services will start in the coming months.

MB: We are based in France in three different sites: Paris, Toulouse and Aix-en-Provence. We will take part in online conferences and exhibitions within the next few months, and keep our community updated on our LinkedIn page. To see the prototypes and initiate some discussions, do not hesitate to contact us.

MB: Microelectronics and photonics projects are defined by the European Commission as an Important Project of Common European Interest (IPCEI). Curved imaging sensor technology is part of it. It is a real asset for European companies, and SILINA is bringing it at a large scale. To know more about SILINA, do not hesitate to contact us.
LinkedIn – Contact: founders@silina.io

Interviewee

Michael Bailly is the CEO of SILINA. He holds an Engineering degree in physics from Ecole Polytechnique and a Master’s in Management of Technology from UC Berkeley. Most of his professional career has been spent managing and setting up First-Of-A-Kind industrialization projects in long cycle technological industries.
In 2008, he started working as project manager at Areva, at the core of the next-generation nuclear plants. He set up new offer processes to streamline technological proposals and facilitate procurement and construction coordination.
In 2013, he joined Air Liquide as project director, leading the construction of innovative hydrogen and oxygen plants in France, Turkey, and Spain, and managing the scaling of technologies applied on smaller units.
In 2020, he decided to start a new challenge by creating a startup within the Entrepreneur First incubator in Paris, where he met his co-founder, CTO and inventor of SILINA’s technology.

Interviewer

As a Technology & Market Analyst, Displays, Zine Bouhamri, PhD is a member of the Photonics, Sensing & Display division at Yole Développement (Yole).
Zine manages the day to day production of technology & market reports, as well as custom consulting projects. He is also deeply involved in the business development of the Displays unit activities at Yole.
Previously, Zine was in charge of numerous R&D programs at Aledia. During more than three years, he developed strong technical expertise as well as a detailed understanding of the display industry.
Zine is author and co-author of several papers and patents.
Zine Bouhamri holds an Electronics Engineering Degree from the National Polytechnic Institute of Grenoble (France), one from the Politecnico di Torino (Italy), and a Ph.D. in RF & Optoelectronics from Grenoble University (France).

Related report

Status of CMOS Image Sensor Industry 2020
The CIS industry overheated in 2019 reaching $19.3B. Are we heading to a soft landing in 2020-2021?