Trends in measurement technology and instrumentation

Measurement techniques and instruments involve the measurement of all physical quantities and are closely related to materials, engineering science, and energy science. The current development trend has the following points:

(1) Tracing and transmitting on a natural basis while achieving international comparisons at different ranges. If you don't have the ability to compare, you have to rely on other countries.

(2) High precision. At present, the typical line width of the semiconductor process is 0.25 μm and the transition is 0.18 μm. The predicted line width in 2009 is 0.07 μm. If the positioning requires 1/3 of the line width, accuracy of the order of 10 nm is required, and the wafer size is still increasing to 300 mm. This means that the accuracy of the measurement positioning system is better than 3 × 10 -8 power, and the corresponding laser frequency stabilization accuracy should be on the order of 10 to -9 power.

(3) High speed. At present, the speed of processing machinery has increased to more than 1m/sec. The instruments developed before the 1980s have not adapted to the needs of the market. For example, HP's interferometer market is mostly occupied by Renishaw in the UK because the latter's speed has reached 1m/sec.

(4) High sensitivity, high resolution, and miniaturization. For example, the spectrometer is integrated on a circuit board.

(5) Standardization. The communication interface used to be GPIB and RS232. The high performance standards that may become alternatives are USB, IEEE1394 and VXI. Now, technology leaders are trying to control technical standards, and participation in standard setting is one of the basic research work for instrument development.

The development status of China's instrument technology

(1) Due to the long-term accustomed to copying foreign products, China's instrumentation industry lacks innovation ability and cannot keep up with the needs of scientific research and engineering construction.

(2) A large number of scientific research achievements have been accumulated in the field of instrument science and technology research in China. Many of the achievements are at the international advanced level and need to be selected, improved and transformed, but the degree of industrialization is very low, and there is no complete industry with international competitiveness.

Future trends

1. Development direction and frontier of discipline

(1) Cooperate with technical innovation of numerical control equipment (such as spindle speed, precision creation)

The main sources of error for CNC equipment can be divided into geometric errors (a total of 21 items) and thermal errors. For recurring systematic errors, software corrections can be used; for large random errors, real-time correction methods should be used. For thermal errors, it is generally corrected by temperature measurement. One of the reasons why China's machine tool industry market shrinks and imports a large number of foreign equipment is because the technology in this area has not been promoted and applied. To this end, a high-speed multi-channel laser interferometer is required: its measurement speed is above 60m/min, and the sampling speed is more than 5000 times/sec to meet the needs of thermal error and geometric error measurement. The real-time measurement of the refractive index of the air should reach a level of 2 × 10 -7, and the measurement results and length measurement results can be input to the computer simultaneously.

(2) Monitoring and online detection technology for operation and manufacturing processes

Sensors that combine the principles of image, spectrum, spectroscopy, fiber optics, and other interactions between light and matter have the advantages of non-contact, high sensitivity, high flexibility, and a wide range of applications. The world of comprehensive innovation in this field is very broad, such as vibration, roughness, pollutants, water content, processing size and mutual position measurement.

(3) Cooperate with the technological innovation of information industry and production science

In order to find a living space in an open environment, there is no way out without independent innovation. Therefore, some projects should be selected according to the principle of patent, technical content and market. According to the current development status, products needed in the fields of information, life medicine, environmental protection, agriculture, etc. should be given priority support. Such as precision instrumentation for interventional therapy in medicine, super-resolution lithography and cleaning methods in the electronics industry, and mechanism research.

2. Priority area

In the early days of basic research, it is difficult to predict whether there will be breakthroughs. However, when breakthroughs have been made, there is a need for a conversion mechanism to enter the market.

(1) Nano-tracking technology and systems.

(2) Coordinate tracking measurement system for interventional installation and manufacture.

Key theories and techniques: super hemispherical reflectors (n=2 or innovative in the field), fast, multi-channel interferometers (frequency difference 3 to 5 megabytes), two-dimensional precision tracking angle measurement system (0.2′′ to 0.5′′), General purpose signal processing system (operating frequency 5 megabytes), railless semiconductor laser measuring system (resolution 1 μm), thermal deformation simulation, force deformation simulation.

These contents are not limited to one technical solution, but are common to several different technical solutions. If the trackless interferometer is used, the requirements of the tracking system can be reduced; the two-dimensional precision tracking angle measuring system can obtain high precision in the 1M3 measuring range; the super hemispherical mirror can improve the accuracy of the 4-way tracking scheme. Intervening in the field of manufacturing and assembly can't wait for a long time. Compensation for force and thermal deformation is necessary and needs to be fast enough. There is still a considerable gap in the current technology, so these developments are critical.

Applications: Identification of new parallel mechanism machine tools, identification of aircraft assembly frames, installation of large equipment, calibration of biochip precision robots, etc.

(3) Non-contact probes and various scanning probe microscopes

The aerospace industry has put forward urgent requirements for this, which is the key technology for the development of coordinate measuring machines in the future. At present, the contact probe has been completely monopolized by foreign countries, and the non-contact probe has not yet matured. We have the opportunity to participate in competition. The principle of laser triangulation, which was used in the past, is subject to many restrictions, and it is difficult to make breakthroughs, but it can work hard on principle innovation. Should break through the resolution of 0.1 ~ 0.5μm.

(4) Computer Aided Measurement Theory

Standardization, modularization, compatibility and integration of signal processing systems. For example, most of the current ISA bus, IEEE 488 port, the computer may cancel the ISA bus in the future, the USB interface for notebook computers will be widely used. In the past, the instruments produced in China were satisfied with digital display, and there was no data exchange interface, making it difficult to enter the international market. Instruments produced abroad are generally equipped with IEEE488 (GPIB) ports. RS232: The high performance standards that are currently available as alternatives are USB, IEEE 1394 and VXI. This turning point provides us with an opportunity. At present, the working frequency band of virtual instruments is on the order of kilohertz, which is too low for interference signal processing. It can be combined and complemented to form a series of modules, while reducing costs and improving the efficiency of R&D work as a whole. Based on the existing foundation, the development of specialties is conducive to overcoming repeated research.

(5) New devices, new materials

In the past, research evaluation systems were biased towards the whole machine and system, ignoring the trend of materials and devices. New breakthroughs may occur in new light sources and new high-frequency detectors. At present, the response frequency of the detector is only 10 to the power of 9 and the optical frequency is up to 10 to the 14th power. At present, the interferometer actually acts as a mixer, adapting to the shortage of the detector (if the response of the detector is really good) Exceeding the optical frequency, the interferometer is useless). If the performance of the detector is significantly improved, it is a big breakthrough for communication.

(6) Research and innovation of measurement characteristics of semiconductor lasers
Semiconductor lasers need to solve many problems (such as line width, calibration, frequency conversion, etc.) for metering. But if many problems are solved, semiconductor laser systems are more complex than gas laser systems and will not be competitive. Some problems are not completely solved at the physical level. For example, if a semiconductor laser can form a dual frequency, it is undoubtedly a very important feature. If it can sweep both frequency and two similar frequency, it will become a new trackless measurement tool.

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