China in CMOS arena.
There are now eight Chinese CMOS image sensor manufacturers, which has grown from four 10 years ago, according to Koifman.
He noted that Chinese sensor firms have managed to reduce costs to a very low level. In 2017, Superpix released a QVGA sensor with integrated ISP priced at $0.068, at the time the most competitive QVGA chip on the market.
Koifman said that 20 years ago such a chip would cost $50 or $30. ‘It’s a big achievement,’ he said.
These price reductions are not attained solely by using inexpensive foundries, but also by making efficient use of silicon area, Koifman observed – by being able to reduce the area around the pixel array. Some Chinese companies, like Galaxycore, excel in area optimisation.
‘In terms of performance, it’s [CMOS technology from Chinese firms like Superpix] not at the level of Sony or Omnivision, but not that far away.’
The other Chinese company Koifman highlighted was GPixel, which was founded in 2012 with headquarters in Changchun, China and offices in Yokohama, Japan and Antwerp, Belgium. He said that the firm has ‘won a huge following’, especially in the industrial sector, with many companies switching to GPixel sensors.
Koifman put GPixel’s success down to, in part, being able to deliver shipments without delay. He said that some image sensor companies can announce sensors that are not ready for full-scale production, and which are delayed for long periods of time. ‘GPixel somehow managed to deliver on their promise time after time,’ he said.
GPixel has access to a low-volume, high-end BSI fab through YCM in Changchun, which supports 8-inch and 12-inch wafer sizes. The company’s sCMOS products are BSI compatible.
In his presentation at the conference, Wim Wuyts, chief commercial officer of Gpixel, said that the firm also has access to 3D stacking technology for high-end products, also through YCM.
‘It [3D stacking] opens up a different dimension where we [Gpixel] can increase the readout speeds significantly,’ Wuyts said, adding that this technology will overcome some of the physical challenges associated with a monolithic approach.