Enlarge /. A very exaggerated picture of the Qualcomm sensor. It's not that big.
Qualcomm brings with the "Qualcomm 3D Sonic Sensor Gen 2" a new fingerprint sensor for smartphones on the screen. Qualcomm says its ultrasonic fingerprint sensor "will come in new sizes that are 50% faster and 77% larger than Gen 1," but still looks pretty small compared to a fingerprint. Just like the Gen 1 version appeared in the Galaxy S10 and S20, there's a good chance you'll see this sensor in the upcoming Galaxy S21.
In-screen fingerprint readers can be fast, accurate, and reliable provided you actually hit their middle, which can be challenging. Being under a smooth, flat sheet of glass means there is no tactile guide on where to put your finger. Early generation fingerprint readers were quite small and required precise accuracy to hit the sensor. An on-screen fingerprint reader big enough to never miss without looking would be a huge improvement, and while we've seen companies talk about such a product, no one has brought one to the market.
In December 2019, with the announcement of the "3D Sonic Max", Qualcomm made the impression that it had achieved its goal of producing a giant fingerprint reader. It sounded like a revolution with a claimed 30mm by 20mm surface area large enough to allow two fingerprints to be scanned side by side. I don't think you'd ever want to do that, but the point is that you would never miss the scan area because it is so big. The 3D Sonic Max doesn't have a commercial version yet, but Qualcomm informs us that it will ship in a product before the end of 2021.
Enlarge /. Qualcomm's first-generation sensor in the Galaxy S10 next to a fingerprint. The S20 had the same sensor.
As OEMs drag their feet in giant leaps in the size of the fingerprint reader, Gradcomm may be able to attract more customers through incremental changes. I measure my fingertip at around 14mm × 14mm, but Qualcomm's first generation sensor available for the Galaxy S10 and S20 only measures part of your fingerprint with a scanning area of 9mm × 4mm. At just 8mm x 8mm, this second generation version still isn't what I would call a "full fingerprint" sensor, but there is now a bigger vertical target. Qualcomm's art above seems to greatly exaggerate the scaling of the sensor relative to a finger and shows what I would measure closer to a 20mm × 20mm sensor.
It's also important to note that Qualcomm doesn't have much to do with its fingerprint readers right now. While every smartphone company in the world uses Qualcomm modems, and Android OEMs ship a ton of Qualcomm SoCs, there is virtually only one company that ships Qualcomm fingerprint readers: Samsung. The vast majority of Android phones use on-screen optical fingerprint readers, usually from Goodix or Synaptics, instead of the Qualcomm solution.
Speaking of Samsung, it sounds like this fingerprint reader is in the Galaxy S21, which launches this week. Last month, affiliate Samsung leaker Ice Universe announced that the Galaxy S21's fingerprint sensor would be ultrasound and measure 8mm by 8mm, which is in line with the specifications announced by Qualcomm today. After Qualcomm's first generation fingerprint sensor shipped in 2019 and 2020, an upgrade of the fingerprint sensor for the Galaxy line is overdue.