PCC: Quartz and silicon microcomponents for accelerometers and gyroscopes

2022: Announcement of development of quartz and silicon microcomponents for accelerometers and gyroscopes

On April 18, 2022, Russian Space Systems announced the development of group processing technology for quartz and silicon microcomponents for accelerometers and gyroscopes, the most important products for navigation and control of space and aviation technology.

RKS has developed a technology for group processing of quartz and silicon microcomponents for accelerometers and gyroscopes

According to the company, the task of navigation, determining the location of an object relative to the reference coordinate system has been solved since the person went on the road. The distance and location traveled were calculated using tools, for example, sextant and simplest calculations. The era of aviation and cosmonautics made it possible to solve the problem of inertial navigation - navigation relative to the inertial coordinate system - automatically using on-board systems.

For more than half a century, inertial navigation systems have undergone tremendous changes: from 80-kilogram gyro-stabilized platforms (GPS) to free-form inertial navigation systems (BINS) weighing tens of kilograms. Systems calculate navigation solution based on signals of angular velocity sensors and accelerometers. As angular velocity sensors, two-power, dynamically adjustable, laser, fiber-optic and wave gyroscopes are used. For measurements of apparent acceleration, gyroscopic integrators of linear accelerations, pendulum and quartz accelerometers are used. If in GPS the platform itself is an analog integrator, then in BINS the problem is solved using digital computers.

Devices with such weights and dimensions cannot be installed on miniature products, such as a quadcopter, a small spacecraft, a spacecraft of type CubeSat. However, even for a car such devices are rearranged. For such objects, appropriate solutions are needed - compact, small in mass and with a proper degree of autonomy.

For miniature products, where the accuracy of information is permissible in favor of the mass, the direction of micromechanical gyroscopes and devices based on them develops. A micromechanical gyroscope the size of a match box provides products with measurements of angular velocity and apparent acceleration. However, like other gyroscopes, the micromechanical gyroscope is a high-tech product, the manufacture of which has a number of difficulties.

Technologies for the production of micromechanical gyroscopes are similar to technologies for the production of electro-radio products, world topological standards have already reached a level of 0.35 micrometers. In 2022, with high demand for miniature inertial sensors, there are difficulties in developing manufacturing technologies and a shortage of serial manufacturers of sensitive elements. A number of Russian enterprises in this niche individually produce such microcomponents, but each product has its own geometric dimensions, they must then be finalized and laboriously brought to the standards necessary in space.

In response to this problem, the PCC has developed group technologies when sensitive elements with the same geometry are made on one plate. Serial production will move away from the practice of piece-by-piece "manual" manufacture. A key feature of the methods developed in the PCC is the optimization of accuracy and repeatability of geometric dimensions of volumetric microstructures.

Sensitive elements

TV RKS has been developing and optimizing this technology since 2007. We use microelectronic production processes: the formation of thin-film dielectric and conductive layers, photolithography, liquid and plasma chemical selective etching and others. To create sensitive elements, materials made in Russia are used. Andrey KORPUKHIN, Deputy Head of the Department for the Development of Micromechanical Systems of the RCS

The launch of production showed that the yield of suitable microcomponents corresponding to the design documentation reaches 70%, while with other methods these indicators do not exceed 30%. Thanks to the technologies used in the PCC, the accuracy of silicon elements of the microelectromechanical system of accelerometers and gyroscopes up to 1 micrometer was achieved and the accuracy of microtreatment of quartz sensitive elements was optimized by 5 times compared to traditional technologies.

Accelerometers and gyroscopes will be accurate and small - the weight and power consumption of satellites will decrease. The achieved parameters open up opportunities for their operation in harsh conditions of open space. These devices will be used in control systems and autonomous navigation of launch vehicles, on orbiters, interplanetary and descent modules. In the future, they will become the basis of gyroscopes and accelerometers of promising spacecraft - from cubsats to interplanetary stations.

Technological microcomponents have great commercial potential, as they have become widespread in non-space areas. For example, they are also used in oil well drilling, transportation, aviation, air, ground unmanned systems, industrial equipment and various portable devices. The accuracy of production will allow them to be used in navigation-class instruments and a wider segment of high-end equipment.

Mathematical processing of information of micromechanical gyroscopes, signal receiver of satellite navigation systems and stellar sensors allows determining navigation parameters with the proper accuracy, which is necessary for operation of the spacecraft motion control system. The RCC solution combines a computer system on a chip, combined with a navigation receiver, micromechanical gyroscopes and information from stellar sensors - such a miniature system with joint processing of primary information and filtering methods will provide a comprehensive solution to the navigation problem.