Tiangong-1 carrier rocket pressure sensor

Reading: The successful launch of “Tiangong I” is inseparable from the normal operation of the launch vehicle. It is reported that the rocket body is equipped with eight pressure sensors, specifically recording the pressure changes during the flight of the rocket, and the production unit of these sensors is a private enterprise in Nanjing - Gaohua Technology Co., Ltd.

Function: Pressure sensor provides corrections for rocket flight

According to Li Weiping, General Manager of Gaohua Science and Technology, eight pressure sensors were deployed on the loading rocket of Tiangong-1 and were installed on bundled boosters and fairings. In the more than 500 seconds since the rocket was launched into the orbit, the pressure sensor had only 400 seconds of working time with the cowling coming off, but the effect was not small. The various pressures experienced by the rocket during the flight are recorded by the sensor in real time, and then transmitted from the control system to the ground remote sensing center. The ground simulation software calculates the theoretical value of the pressure, based on the flight altitude and other parameters. The data from the sensors is compared to understand how the rocket is flying. The sensor data is collected in real time, and the remote sensing center observes it at regular intervals. “This data is very important for the next design of the rocket flight. For example, after the rocket enters the stratosphere, the pressure data returned by the rocket is different from the theoretical data. This may be a problem with the rocket’s rocket during the flight and the pressure is changed. The next flight will be amended," said Li Weiping.

Development: technicians use six months to craft

The pressure sensor is built into the stainless steel package, and then packaged by soldering the circuit board. It has a wide range of uses, and it is used in many places in automobiles and medical machinery, but the pressure sensors used on rockets are the most demanding. "First, the volume must be small, and the lighter the better. Second, the reliability must pass. In the acceptance process, we must go through a variety of environmental tests to ensure that the rocket can work after taking off at high speed." Li Weiping Take a sample from the company's showroom to the reporter. The sensor is 26 mm in diameter and only a dozen centimeters high. It weighs a few dozens of grams and looks like a normal big nut. But it can be below minus 20 Celsius to 60 degrees Celsius above zero and a variety of strong magnetic, vacuum environments.

"This small thing, we spent more than six months to manufacture." The staff said that the principle of the pressure sensor is the external pressure on the silicon chip, through the integrated circuit to change the force signal into an electrical signal output. "Since it's simple, there are no more than a few hundred processes in it. All welding and packaging must be done under a microscope." The staff member said that when dealing with the sheath of the wire, the sheath was generally scraped off with a wire stripper. However, it is easy to damage the copper metal layer inside, and later the R&D staff tried to use a hot stripper to iron off the skin, and this gave satisfactory wires. In the manufacturing process, examples of such fine-grained operations are numerous.

Goal: To be a world-class sensor company

Li Weiping said that the competition has provided three units for the Tiangong No. 1 pressure sensor and the other two are military production enterprises. In the final competition, Gao Hua’s products came to the fore and successfully won the bid. “Our product is half the size of the other two companies and we have a stronger reliability. Therefore, we chose us last.” Li Weiping said that there are thousands of companies that produce pressure sensors nationwide, but they can still achieve the level of space products. Family. All of this benefits from the team’s R&D capabilities. Gao Hua Company was founded by several masters from Nanjing University and Nanjing University of Science and Technology. “At that time, I was exposed to sensor technology for the first time and I felt that there was great potential. Several of us established this company.” Li Weiping said that at present, the company has established cooperative relations with Peking University, NTU, Dongda and famous research institutes in China. , With Nanjing MEMS (Micro Electro Mechanical System) Sensor Engineering Research Center, is a rare domestic master all key process technology manufacturers.

At present, the annual output value of the company is 50 million yuan, and the annual production of sensors reaches 200,000, but Li Weiping is not satisfied. “The annual output of world-class sensor companies is more than a million, and we will continue to do large-scale.” In addition, Gao Hua is also seeking to create a complete industrial chain to break the domestic companies mainly package, most of the chip Imported "strange circles". "Nanjing Intertek Co., Ltd. is developing sensor chips with proprietary intellectual property rights. We are working with them. Once successful, the sensors produced will be fully localized."