Since the beginning of this century, CMOS image sensor has replaced CCD image sensor, leading the revolution in the field of photography and imaging, and bringing a prosperous new market. However, in the past decade, the iteration of CMOS technology represented by stackable technology seems to have come to a standstill.

However, Gekoway seems to have found a new direction of breakthrough. On the evening of October 16th, Geke Micro issued an announcement announcing its mass production of 32 million-pixel image sensors using the company's self-developed high-pixel single-chip integration technology. From the successful research and development of high-pixel single-chip technology, to the launch of 32 million-pixel products, and then to mass production, Gekow's new technology path is constantly being recognized by brand customers, which may bring new vitality to the field of CMOS image sensors.

From CCD to CMOS, the way to the Development of Image Sensor

In 1969, Willard S. Boyle and George E. Smith invented the first practical charge coupled device (CCD) image sensor in Bell Labs. The CCD sensor captures the image by storing the charge in the photosensitive area of the pixel and converts the charge into a voltage signal. The invention of CCD image sensor not only makes photography more convenient, efficient and economical, but also provides more possibilities for image storage and sharing. Because of its obvious advantages, CCD image sensor has been widely used commercially as soon as it came out. Traditional film photography has been gradually replaced, and the new wave of digital photography has officially begun.

Another leap in image sensor technology can be traced back to the emergence of CMOS image sensors in the early 1990s. However, the real rise of CMOS in the market and the establishment of its dominant position took place in the late 2000s. With the rise of smart phones, CMOS image sensors gradually replace CCD with its advantages of low cost, low power consumption, small area and integration, and become the largest image sensor category in the market share.

According to the data of head Leopard Research Institute, with the continuous expansion of the application field of CMOS image sensor, the global CMOS image sensor market is still growing rapidly. It is expected that the global CMOS sensor market will grow to 237.4 billion yuan in 2026, with a compound annual growth rate of 11.8% from 2021 to 2026.

Within the CMOS image sensor, three key technical iterations also took place. Since the 21st century, the mainstream CMOS image sensor technology has changed from FSI to BSI, and then developed into Stacked. These three upgrades are all dominated by overseas giants such as Sony Group Corp and Samsung Electronics, so these overseas manufacturers naturally occupy the main market position. However, the domestic CMOS chip sensor starts relatively late, the middle and high-end products basically rely on imports, and there is a broad space for domestic substitution.

In the competition of middle and high-end products, if Chinese manufacturers adopt the same technological path as overseas manufacturers, they need to compete with competitors with a first-mover advantage under the rules set by existing market leaders. This is not a fair game. But if they can open up new technological paths, Chinese manufacturers will have the opportunity to become pioneers of new categories, makers of new rules and leaders of new standards, and have a good chance to change lanes and take the lead.

In this hope, Gekowi began to explore a new path.

Chinese manufacturers who change lanes to overtake

In retrospect, stackable chips are popular because they can stack vertically to integrate processors, sensors and other different functions. Compared with the monolithic sensor, the stack sensor has the advantages of high imaging quality, low light performance, better dynamic range and so on.

However, the stack type also has some obvious disadvantages: the stack type is more complex than the monolithic CMOS sensor, so the manufacturing cost is usually higher; in addition, the multi-layer structure may cause heat accumulation and thermal noise problems. It should be noted that stackable is the latest key technology upgrade of CMOS image sensor, which was first launched by Sony Group Corp in 2012. This means that there has been no major change in CMOS technology for more than a decade, and international manufacturers have occupied a dominant position in the market with stackable technology for many years.

However, Geke Micro's high-pixel single-chip technology and the world's first single-chip 32 million-pixel CMOS image sensor GC32E1 have brought new vitality and expectations to the market. GC32E1 is developed based on GE Micro's latest FPPI patented technology, and its monolithic structure naturally has a better heat dissipation effect, avoiding the pixel thermal noise problem caused by the heat of the lower stack logic chip in the stack structure. Excellent performance in dark current, thermal noise, high temperature white spots and other indicators, especially in high temperature conditions with excellent image performance. At the same time, compared with the stackable 32 million pixel image sensors on the market, GC32E1 has only increased its area by about 8%, forming a very advantageous cost structure.

In addition, in August this year, Geke Micro released the industry's first 13 million-pixel image sensor GC13A2 that supports high dynamic single frame. The so-called single-frame high dynamic is the DAG HDR technology developed by Geke Micro, which uses high analog gain in the dark part based on a single frame to make the dark part clearer and more textured; bright parts use low analog gain to avoid over-exposure whitening, retain details, and finally output high dynamic range images. Compared with the traditional multi-frame HDR, DAG HDR can not only increase the dynamic range, avoid artifacts, achieve accurate restoration, but also reduce the power consumption caused by multi-frame synthesis.

Left: dynamic range is not enough, highlight details are missing. Right: DAG HDR (photo source: Geke WeChat account)

Integrating the content previously released by Geke Micro, the follow-up company is likely to continue to launch high-pixel products with DAG single-frame high-dynamic based on high-pixel single-chip integration technology. From this, it can be seen that Geke Micro is constantly upgrading and iterating, creating products with both cost and performance advantages through innovation and integration in structure, process, circuit and other aspects, opening up new paths beyond stackings, and creating new transcendental paths.

This Geke micro announcement "Guanxuan" its 32 million pixel product mass production, fully shows that the product has been recognized by the downstream market. From the emergence of high-pixel single-chip technology and related products to the commercial landing, the time is not long enough to see that the technology and products have sufficient market competitiveness, confirming the leading level of this technology. After years of international manufacturers leading the market with stackable style, Geke Micro is expected to open up a new technological direction for Chinese image sensor manufacturers, and may even redefine the global CMOS image sensor market.