China sees boost for arms stockpile with DUV breakthrough for chip-based gyroscopes: paper

[Nan Yang]

China sees boost for arms stockpile with DUV breakthrough for chip-based gyroscopes: paper​

• Chip-sized optic gyroscope paves way for mass production of low-cost missiles, say defence industry engineers
• Arms producers must ‘further cut the cost, reduce size and greatly increase shipment volume to meet the military’s urgent demand’, say authors

Stephen Chen in Beijing
Published: 10:30pm, 1 Mar, 2023

Laboratory testing shows the accuracy of chip-based gyros tested by a defence industry team surpassed that of mainstream products currently used in China’s short-range missiles by about 30 per cent. Photo: China Military Online

China has developed a low-cost fibre-optic gyroscope that can be mass-produced in an old-fashioned computer chip plant, speeding up the delivery of tactical missiles and other guided weapons to the Chinese military stockpile, according to defence industry engineers.

The technology is available in only two countries – China and the United States – according to the research team led by Mao Yuzheng, a senior engineer with the Xian Flight Automatic Control Research Institute under the Aviation Industry Corporation of China.

China was moving fast but remained about two years behind the US in this “disruptive” chip race, said Mao and his co-authors from the People’s Liberation Army equipment department in a paper published in the Journal of Chinese Inertial Technology on Monday.

The gyroscope enables a missile to automatically correct its turn and pitch motion in flight, even when its GPS is down.

Chinese engineers built a fibre-optic gyroscope on a grain-sized chip – compared to the bowl-sized ones in present use. Photo: Xian Flight Automatic Control Research Institute, Aviation Industry Corporation of China

Mechanical gyroscopes have in recent decades been replaced mainly by fibre-optic gyros that are accurate without using moving components.

A typical fibre-optic gyro is the size of a rice bowl, and making the device is onerous for missile producers, according to Mao’s team.

“At present, the core components of traditional fibre-optic gyroscopes all come in discrete packages which are large. Making and assembling these components requires many procedures that are time consuming and demand lots of manpower,” Mao’s team said in the paper.

“The manufacturing cost is high while production scale and capacity remains small.”

They added that China’s defence industry must “further cut the cost, reduce size and greatly increase shipment volume to meet the [military’s] urgent demand

Mao’s team created optic fibres and other components on a silicon chip about the size of a grain of rice.

The chip technology reduces the size of the gyroscope to 1/12th of the original product, according to their paper.
Laboratory testing showed that the accuracy of chip-based gyros surpassed that of mainstream products used in China’s short-range missiles by about 30 per cent.

“With the help of photolithography technology, hundreds or even thousands of photonic chips can be processed on a single wafer at one time,” Mao’s team said.

Consistency of product quality and scale production effect was also “greatly improved”.

“The traditional fibre-optic gyroscope manufacturing mode will be turned upside down,” they added.

The chip was made with deep ultraviolet (DUV) photolithography at 248 nanometres (nm), a mature process in semiconductor fabrication that has been around for more than two decades.

Mao’s team said it had worked with a foundry in China, but did not name it.

The US government is reportedly seeking to expand the sanctions list on China’s semiconductor industry to target older technologies such as DUV.

Japan and the Netherlands agreed last month to join the US in banning the export of DUV photolithography machines to China, although companies in these two countries said earlier that the measure would have limited effect on China, which had the mature technology.
The 248nm fabrication process was more reliable than newer fabrication technology, such as those using 7nm technology, but it took a toll on the chip gyroscope’s performance, Mao’s team said, adding that the tiny chip consumed more electricity than desired, and its positioning accuracy was lower than similar products received by the US military in 2020.

As chip-making technology advances in China, the cost and size of missile gyroscopes “is expected to be further reduced in mass production”.

“There will also be a huge demand in other fields such as civil aviation, autonomous driving and intelligent robots,” the paper said.