1) Miniaturization: MEMS devices have small size, light weight, low energy consumption, small inertia, high resonant frequency and short response time.
2) Using silicon as the main material, it has excellent mechanical and electrical properties: the strength, hardness and Young's modulus of silicon are equivalent to iron, the density is similar to aluminum, and the thermal conductivity is close to molybdenum and tungsten.
3) Mass production: Using silicon micromachining technology, hundreds or thousands of micro-electromechanical devices or complete MEMS can be manufactured simultaneously on a single silicon wafer. Mass production can significantly reduce production costs.
4) Integration: Multiple sensors or actuators with different functions, different sensitive directions or actuation directions can be integrated into one, or a micro-sensor array, a micro-actuator array, or even a variety of Functional devices are integrated together to form complex microsystems. The integration of microsensors, microactuators and microelectronic devices can create MEMS with high reliability and stability.
5) Multidisciplinary intersection: MEMS involves many disciplines such as electronics, machinery, materials, manufacturing, information and automatic control, physics, chemistry and biology, and integrates many cutting-edge achievements in the development of today's science and technology.
The goal of MEMS development is to explore new principles and new functional components and systems through miniaturization and integration, and to open up a new technology field and industry. MEMS can complete tasks that cannot be accomplished by large-scale electromechanical systems, and can also be embedded in large-scale systems, raising the level of automation, intelligence, and reliability to a new level. In the 21st century, MEMS will gradually move from laboratories to practical applications, having a major impact on industry and agriculture, information, environment, bioengineering, medical care, space technology, national defense and scientific development.
Microelectromechanical systems are micron-sized mechanical systems, which also include systems produced by three-dimensional lithography of different shapes. The size of these systems typically ranges from micrometers to millimeters. Everyday physical experience often does not apply in this size range. For example, since the area to volume ratio of microelectromechanical systems is much larger than that of ordinary mechanical systems in daily life, its surface phenomena such as static electricity and wetting are more important than volume phenomena such as inertia or heat capacity. They are generally manufactured by technologies similar to those used to produce semiconductors, such as surface micromachining and body micromachining. These include changed silicon processing methods such as calendering, electroplating, wet etching, dry etching, EDM, and more. MEMS refers to a micro-electromechanical system that integrates micro sensors, actuators, signal processing and control circuits, interface circuits, communications and power supplies. It is an independent intelligent system. It is mainly composed of three parts: sensors, actuators and micro-energy sources. Microelectromechanical systems have the following basic characteristics: miniaturization, intelligence, multi-function, and high integration. Microelectromechanical systems. It explores components and system micro-electromechanical systems with new principles and new functions through system miniaturization and integration. Microelectromechanical systems involve application fields such as aerospace, information communications, biochemistry, medical care, automatic control, consumer electronics, and weapons. The manufacturing processes of microelectromechanical systems mainly include integrated circuit processes, micron/nano manufacturing processes, small machinery processes and other special processing types. The technical foundation of MEMS mainly includes design and simulation technology, material and processing technology, packaging and assembly technology, measurement and testing technology, integration and system technology, etc.
Features
① Same as semiconductor circuits, using etching, photolithography and other manufacturing processes, no assembly or adjustment is required;
② Further, mechanically removable circuits can be The moving parts, electronic circuits, sensors, etc. are integrated on a silicon board;
③It takes up very little space and can be used in narrow places or places with harsh conditions that ordinary robots cannot reach;
④Due to the small mass of the working parts, high-speed action is possible;
⑤Due to its small size, the influence of thermal expansion is small;
⑥The force and savings it generates The energy is very small and inherently safer.
Advantages
Economic benefits:
1. High-volume parallel manufacturing process;
2. System-level integration;
3. Package integration;
4. Compatible with IC technology.
Technical benefits:
1. High precision;
2. Light weight, small size;
3. High efficiency.
MEMS optical scanner
With the rapid development of information technology and optical communication technology, another area of ??MEMS development is the combination with optics, that is, integrating basic technologies such as microelectronics, micromachinery, and optoelectronics technology to develop A new type of optical device is called micro-optical electromechanical system (MOEMS). It can completely integrate various MEMS structural parts with micro-optical devices, optical waveguide devices, semiconductor laser devices, photoelectric detection devices, etc. Form a new functional system. MOEMS has the characteristics of small size, low cost, mass production, and precise driving and control. The more successful applied scientific research mainly focuses on two aspects:
First, new display and projection equipment based on MOEMS, which mainly studies how to spatially modulate light through the physical movement of reflective surfaces. Typical representatives are: Digital micromirror array chip and grating light valve: The second is the communication system, which mainly studies the physical movement of micromirrors to control the expected changes in the optical path. The more successful ones include optical switching modulators, optical filters and multiplexers and other optical communications device. MOEMS is a highly comprehensive and interdisciplinary high-tech technology. Scientific and technological research in this field can drive the development of a large number of new concepts and functional devices. RF MEMS technology is traditionally divided into two categories: fixed and movable. Fixed MEMS devices include body micromachined transmission lines, filters and couplers, and movable MEMS devices include switches, tuners and variable capacitors. According to the technical level, it is divided into the basic device level consisting of micromechanical switches, variable capacitors and inductive resonators; the component level consisting of phase shifters, filters and VCOs; and the monolithic receiver, variable beam radar, phase The application system level composed of controlled array radar antennas.
With the passage of time and the gradual development of technology, the content contained in MEMS is increasing and becoming richer. The world-famous information technology journal "IEEE Proceedings" summarized the contents of MEMS in the 1998 MEMS special issue as: integrated sensors, microactuators and microsystems. People also classify micromachines, microstructures, smart sensors and smart sensors into the MEMS category. The technology for making MEMS includes two parts: microelectronics technology and micromachining technology. The main contents of microelectronics technology include: oxide layer growth, photolithography mask production, photolithography selective doping (shielding diffusion, ion implantation), thin film (layer) growth, wiring production, etc. The main contents of micromachining technology include: silicon surface micromachining and silicon body micromachining (anisotropic etching, sacrificial layer) technology, wafer bonding technology, LIGA technology for producing high aspect ratio structures, etc. Integrated circuits and many sensors can be manufactured using microelectronics technology. Micromachining technology is very suitable for making certain pressure sensors, acceleration sensors, micropumps, microvalves, microgrooves, microreaction chambers, microactuators, micromachines, etc. This can give full play to the advantages of microelectronics technology and use MEMS technology to manufacture high-reliability microsatellites in large quantities and at low cost.
MEMS technology is an emerging technology field, mainly belonging to the category of micron technology. The development of MEMS technology has gone through more than 10 years. Most of them are based on existing technologies and produced using technical approaches ranging from large to small. A number of new integrated devices have been developed, which have greatly improved the function and efficiency of the devices. It has been shown that great vitality. The development of MEMS technology is likely to have a revolutionary impact on science, technology and human life just like microelectronics. It will especially have a far-reaching impact on the development of micro-satellites, which will surely open the door to mass production of low-cost, high-reliability micro-satellites. .