IHS Markit: FoD screen fingerprinting adds new momentum to fingerprint verification and overall screen trends

When apple introduced the new 3D facial recognition mechanism for the iPhone, some people thought fingerprint identification would be severely challenged, but others thought it would be more intuitive and convenient to use.Now, after a year of improvement, the Android (Android) camp smartphones have adopted the latest fingerprint technology (FoD, fingerprint on the display screen, will the user generally accepted way of fingerprint verification, cooperation has become a mainstream trend of full screen, made a perfect combination of both, also solve the design full screen gap (notch) problem.

The FoD sensor is not designed to be exposed, so the fingerprint sensor area can be placed in the screen without the need for additional space on the body surface, making it suitable for a full screen design.Although the user cannot see the FoD sensor, it can be used on the screen and cover board.Screen fingerprints are also a competitive biometric feature that could replace other biometric methods used in mobile phones, such as iris and facial recognition.Samsung's latest flagship Galaxy S10 series USES on-screen fingerprints and has eliminated iris recognition verification on past flagship models.

According to the latest "screen fingerprint technology and market report -- 2019" published by IHS Markit, FoD module shipments will increase by nearly 580% to 200 million units in 2019 due to its initial and low base of 29 million units in 2018.And if some of the factors affecting shipments this year are positive development in the past, it is estimated that there is a chance to reach 240 million sets.These factors, which affect the shipment like: fingerprint screen solution provider, the number of suppliers to import models related to the degree of support, supplier under a limited number of module prices downward trend, AMOLED panel price, shipment growth concerns the overall smartphone market in 2019, and even the user experience (screen fingerprint could limit the users using third-party screen protective film, and now is not easy to support blind unlock).

Currently, brands that use screen fingerprint solutions in smartphone products include top Chinese brands such as Vivo, huawei, xiaomi, OPPO and lenovo, as well as South Korea's samsung.At present, the major solution suppliers include huiting, shield, sili and qualcomm.Among them, samsung adopts qualcomm's ultrasonic solution and shield's optical solution, which are respectively used in the flagship series of S10 and some models of intermediate series A.Huiding is the main supplier of major mobile phone brands in China.

An updated solution is in development

While screen fingerprints will become increasingly available on android phones, current solutions, whether CMOS image sensor based or ultrasonic based, will only work on AMOLED displays, not TFT LCDS, which account for a larger share.The main reason is that the backlight module under TFT LCD affects the signal reception of the sensor, and once the backlight structure is destroyed to guide the light signal, it may affect the display efficiency of TFT LCD.While some solution providers have proposed ways to use special optical film materials to pass light across specific spectra, more verification of efficiency and cost will take time.

In addition, the screen fingerprint module is integrated under the display screen as an additional component, which increases the total thickness of the entire display component.Finally, the sensing area of CMOS image sensor is limited.This is because current silicon wafer processes are too expensive to produce sensors that can produce larger sensing areas.Some solution vendors are developing side-by-side CMOS image sensor chips to increase the sensing area, but at a relatively high cost.

Although this market is still in its infancy, the industry is already developing future screen solutions to overcome size and thickness limitations.The trend of new solutions is to use the sensor approach based on the TFT process. Currently, qualcomm's ultrasonic sensors have adopted the low-temperature polysilicon process (LTPS TFT).A new solution provider, basket, USES an amorphous silicon process (a-si) to make optical sensors.The panel factory, like au and tianma, is trying to integrate the optical sensing circuit based on TFT process into TFT LCD to become in-cell embedded architecture.If successful, the future of screen fingerprinting could be as much about the future of the touch screen as it is about the future of the touch screen.

Over time, the TFT LCD process's fingerprint technology will become more attractive, according to IHS Markit forecasts.In 2018, silicon-based screen fingerprint sensor solutions dominate the market, accounting for 91 percent of total shipments.However, tft-based screen fingerprint sensor solutions will account for 32 percent of module shipments in 2019.IHS Markit believes that if in-cell embedded solutions for TFT LCDS can be successfully developed between 2020 and 2021, tft-based sensor shipments will grow significantly.