Qualcomm announced a Gen 2 version of 3D Sonic Sensor on 11th January, 2020. This latest version of the Sonic Sensor coming with new sizes that are 50% faster and 77% larger compared to Gen 1. The Gen 1 version was 4x9mm (surface area 36mm2) and the Gen 2 have a sensor that is 8x8 (64mm2), which is 77% larger than Gen 1.
What is the use of 3D sonic sensor
In short the 3D Sonic Sensor is used for in-display fingerprint sensor. Basically, this new technology uses ultrasonic sound waves instead of light to capture the fingerprint for a deeply accurate image . Few flagship smartphones already uses the Qualcomm 3D Sonic Sensors to deliver in-display fingerprint scanning that is fast and reliable too. Samsung Galaxy S10, Note 10, S20 and Note 20 are already using the Gen 1 of Qualcomm's fingerprint sensor.
Improvement in the 3D Sonic Sensor Gen 2
Although the flagship phones used this sensors, but some reliability and security problems was identified in the Gen 1 fingerprint sensors. As the Gen 1 3D Sonic Sensor was small in size, it introduced some problems to read fingerprints accurately, sometimes found a bit slow speeds.
This Gen 2 version of the 3D Sonic Sensor coming with new sizes that are 50% faster and 77% larger compared to Gen 1. The larger sensor provides a larger region for the fat finger like mine and allows the second generation 3D Sonic Sensor to capture 1.7x more biometric data from finger or fingers. And this new Sensor can scan fingerprints through solid surfaces like glass and metal even while wet.
Find more details in Qualcomm site.
Yes fingers, Sound interesting, yes it is 77% large. My idea is in that new size or surface area two fingers can be placed and scanned which can introduce very high security lock in the mobile phone fingerprint scanner. And can be used for many more applications through software tricks. 
