One: What is SMT?
SMT OverviewSMT is an abbreviated form of Surface Mount Technology, which translates to surface mount technology. The United States is the invention of SMT, the world's first surface mount components in 1963 and Flyleaf introduced the first surface mount integrated circuits, SMT has been mainly used in the military, aviation, aerospace and other cutting-edge products and investment products are gradually being widely used in computers, communications, military, industrial automation, consumer electronics and other industries. Into the 80's SMT technology has become the most popular international new generation of electronic assembly technology, known as the electronic assembly technology a revolution. 2: SMT composition: mainly by the surface mount components (SMC / SMD), mounting technology, mounting equipment, three parts. 2.1: Surface mount components (SMC / SMD) 2.1.1: Surface Mount Components (SMC / SMD) Description SMC: Surface mount components, mainly refers to a number of active surface mount components; SMD: surface mount device, mainly refers to a number of passive surface mount components; 2.1.2: SMC / SMD development trend (1): SMC - -Chip components to small, thin development. Its size from 1206 (3.2mm * 1.6mm) to 0805 (2.0mm * 1.25mm) - 0603 (1.6mm * 0.8mm) - 0402 (1.0mm * 0.5mm) - 0201 (0.6mm * 0.3mm) Development. (2) SMD - surface assembly devices to small, thin and narrow pin pitch development. Pin center distance from 1.27 to 0.635mm-0.5mm-0.4mm and 0.3mm development. (3) the emergence of new package forms BGA (ball grid array, ball grid arrag), CSP (UBGA) and FILP CHIP (flip chip). Due to QFP (quad flat package device by the SMT process limitations, 0.3mm pin spacing is already the limit value. While BGA pins are spherical and evenly distributed on the bottom of the chip, the most prominent advantages of BGA and QFP compared to the first is that the number of I / O package area ratio is high, saving the PCB area, and improve the assembly density. Secondly, the pin spacing is larger, there are 1.5mm, 1.27mm and 1.00mm, the assembly difficulty decreases, the processing window is larger. Example: 31mm 31mmR BGA pin spacing of 1.5mm, there are 400 solder balls (I/O); pin spacing of 1.0mm, there are 900 solder balls (I/O). The same 31mm * 31mm QFP-208, the pin pitch of 0.5mm, only 208 pins. BGA is competitive in both performance and price, and has taken a leading role in the packaging of devices with high (I/O) counts. (4) Narrow Pitch Technology (FPT) is an inevitable trend in the development of SMT FPT refers to the pin pitch between 0.635-0.3mm SMD and length * width less than or equal to 1.6mm * 0.8mm SMC assembled on the PCB technology. Due to the rapid development of computers, communications, aerospace and other electronic technologies, prompting the integration of semiconductor integrated circuits is becoming more and more highly integrated, SMC is becoming smaller and smaller, SMD pin spacing is also becoming more and more narrow. At present, 0.635mm and 0.5mm pin pitch QFP has become industrial and military electronic equipment in the communication devices. 2.2: SMT mounting technology introduction: 2.2.1: SMT assembly process types: single-sided / double-sided surface mount, single-sided mixed mount, double-sided mixed mount. 2.2.2: soldering method classification: wave soldering - the soldering of the cartridge (DIP) and part of the SMD (SMC / SMD) of the welding. Reflow soldering - heating methods such as infrared, infrared heating air combination, full hot air heating, etc. 2.2.3: Printed circuit boards: substrate materials - fiberglass, ceramics, metal plate. Circuit board design - graphic design, wiring, gap setting, collocation, SDM pad design and layout, 2.2.2: SMT placement equipment: silk screen printing machine, dispensing machine, SMD machine, reflow soldering, wave soldering, testing systems, maintenance systems
Two: SMT features and current developments
SMT features: 1.1 high assembly density, small size of the electronic product, Light weight, the volume and weight of SMD components is only about 1/10 of the traditional plug-in components, generally after the use of SMT, the electronic product volume is reduced by 40% to 60%, weight reduction of 60% to 80%. 1.2 High reliability and high vibration resistance. Low solder joint defect rate. 1.3 Good high frequency characteristics. Reduced electromagnetic and radio frequency interference. 1.4 Easy to realize automation and improve productivity. 1.5 Reduce cost up to 30%~50%. Save materials, energy, equipment, labor, time, etc. 2, SMT development dynamics: SMT (surface assembly technology) is a new generation of electronic assembly technology. After the rapid development of the 1980s and 1990s, has entered a mature period, SMT has become a wide-ranging, rich in content, across multiple disciplines of comprehensive high-tech. In the last few years, SMT has entered a new development climax and has become the mainstream of electronic assembly technology. SMT is no need to drill insertion holes on the printed board, directly to the prescription components or micro-components suitable for surface assembly device paste, welded to the printed or other substrate surface on the specified position of the mounting technology. As a result of a variety of chip components of the geometric size and volume of space than the plug-in components is much smaller, this form of assembly has a compact structure, small size, vibration resistance, shock resistance, high-frequency characteristics of good and high production efficiency advantages. Using double-sided mounting, assembly density of 5 times to about, so that the printed board area savings of 60% -70%, weight reduction of more than 90%. SMT in the investment class electronic products, military equipment, computers, communications equipment, color TV tuner, video recorders, digital cameras, video cameras, digital camcorders, pocket-sized high-grade multi-band radios, Walkman, MP3, pagers and cell phones, and so on almost all the production of electronic products have been widely used.SMT is the main direction of the development of the electronic assembly technology has become the world's electronic assembly technology. SMT is the main development direction of electronic assembly technology, has become the world's electronic machine assembly technology mainstream. SMT is evolved from thick, thin-film hybrid circuits. The United States is the world's SMD and SMT the earliest origin of the country, and has been attached importance to the field of investment electronic products and military equipment to play SMT high assembly density and high reliability performance advantages, has a very high level. Japan in the 70's from the United States to introduce SMD and SMT applications in the field of consumer electronics, and invested in the world's capital to vigorously strengthen the basic materials, basic technology and promote the application of development and research work, from the mid to late 80's accelerated SMT in the field of industrial electronic equipment in the comprehensive promotion of the application of SMT in the field of only four years to make SMT in the number of applications in computers and communications equipment increased by nearly 30%, in fax machines increased by 40%. The number of SMT applications in computers and communication equipment increased by nearly 30% in only four years, and 40% in fax machines, so that Japan soon surpassed the United States, the world leader in SMT. European countries SMT started late, but they attach importance to the development and have a better industrial base, the speed of development is also very fast, the level of its development and the whole machine in the SMC / SMD use of efficiency is second only to Japan and the U.S. Since the 80's, Singapore, South Korea, Hong Kong and Taiwan Province of Asia's four little dragons have not spared huge sums of money, have been introduced into the advanced technology, so that the SMT to obtain a relatively rapid development. According to Philips predicts that by 2010 the global scope of the use of cartridge components will be from the current and 40% down to 10%, on the contrary, SMC / SMD will rise from 60% to 90% or so. China's SMT applications started in the early 80s, initially from the United States, Japan and other countries to introduce a complete set of SMT production line for color TV tuner production. Subsequently applied to video recorders, video cameras and pocket-sized high-grade multi-band radios, Walkman and other production, in recent years in the computer, communications equipment, aerospace electronics products are gradually being applied. According to incomplete statistics in 2000, China has about 40 companies engaged in the production of SMC / SMD, the country's more than 300 of the introduction of the SMT production line, to varying degrees, the use of SMT. 5,000-7,000 units of the country has been introduced into the mounting machine. With the deepening of reform and opening up as well as accession to the WTO, in the past two years, some of the United States, Japan, Singapore, Taiwan has moved the SMT processing plant to China, only in 2001-2002 a year the introduction of more than 4,000 sets of mounting machines. China will become the base of SMT world processing plant. China's SMT development prospects are very broad. SMT general development trend is: components are getting smaller and smaller, assembly density is getting higher and higher, assembly difficulty is also getting bigger and bigger. In recent years SMT has entered a new development climax. In order to further adapt to the development of electronic equipment to short, small, light, thin direction, the emergence of 0210 (0.6mm * 0.3mm) CHIP year, BGA, CSP, FLIP, CHIP, composite chip components and other new packaging components. Due to the development of BGA and other component technology, non-ODS cleaning and the emergence of lead-free solder, caused by the SMT equipment, soldering materials, mounting and soldering process changes, to promote the development of electronic assembly technology to a higher stage of development. the speed of development of the SMT is indeed surprising, it can be said that every year, every month, every day there is a change.
Three, why learn to use surface mount technology (SMT)?
Why use surface mount technology (SMT)?1.1: the pursuit of miniaturization of electronic products, the previous use of perforated plug-in components have been unable to shrink .1.2: electronic products more complete function, the use of integrated circuits (ICs) has been no perforated components, especially large-scale, high-integration ICs, had to use the surface mount components.1.3: batch products, production automation. Manufacturers have to produce high quality products at low cost and high output to meet customer demand and strengthen market competitiveness. 1.4: The development of electronic components, integrated circuits (IC) development, semiconductor materials, multiple applications 5. electronic technology revolution is inevitable, chasing the international trend. 2, SMT: Electronics Manufacturing Technology Key Manufacturing Technology is the key to the formation of the product is the key to more and more attracted the attention of the business community. With the influx of many multinational companies, China has become a giant in the electronics manufacturing industry. SMT as the most advanced technology in the electronics manufacturing industry, its development is also becoming more and more people's attention. 3, China's SMT SMT professionals are most in need of China's electronics production industry, after the reform and opening up of China's development can be said to be very fast . As the protagonist of the electronic production technology surface mount technology SMT, but also the corresponding high-speed development. This phenomenon is mainly caused by two factors, one is the domestic demand for reform itself, and the other is the huge domestic market for foreign attraction. China has just carried out reforms in the electronics production industry, whether in capital or technology, have to rely on foreign countries. The introduction of foreign capital and technology will not come without a price. On the one hand, the introduction of technology and capital, will make our country SMT development from a poor two hundred to the current thriving. But on the other hand, the development of our country's own electronics industry, can not rely solely on other people's technology, if that, our development is inherently inadequate, is not sustainable development capacity. So for a country, this to rely on foreign assistance-based approach can only be used in the transitional period of development, the long term or must learn their own set of capabilities. To the current situation of China's SMT industry, if we want to improve competitiveness, or even just maintain competitiveness in the direction of what is most needed? The lack of domestic, the most important is the two major aspects of capital and talent. The source of capital, one from the domestic (accumulated through production), the second from foreign investment. The decision of our country's electronics industry, sound, sustainable development depends on our SMT professionals, SMT technology development personnel, SMT technology application personnel, SMT professional and technical personnel is one of the bottlenecks in the development of our current electronics industry. This is for our current training of talents in colleges and universities, training of high-tech SMT personnel, to adapt to the market demand for the development of talent, is the responsibility and obligation without delay. 4, SMT applications more and more widely SMT and our daily life is closely related to our use of computers, cell phones, MP3, printers, copiers, PDAs, Express, electronic notepad, DVD, VCD, CD, Walkman, camcorder, video camera, and so on. Walkman, camcorder, fax machine, microwave oven, high-definition television, digital camera, IC card, there are many high degree of integration, small size, strong function of high-tech control system, are manufactured using SMT production, it can be said that if there is no SMT to do the basis, it is difficult to imagine that we can use these commodities to make life rich and colorful.
Four: the necessity and urgency of the establishment of SMT laboratories in colleges and universities!
In the last decade, the fastest growing industry than the electronics industry, one after another technological innovation to promote the rapid development of the electronics industry. Until today, electronic products have spread to every corner of our life, production and work. Engaged in the electronics industry is also more and more people, so it creates a lot of hardware engineers, software engineers, technical craftsmen and other highly specialized technical personnel. Universities and colleges also continue to all kinds of factories, enterprises, research institutes to deliver a large number of talents. Most of the schools have set up a number of electronic-related specialties, the preparation of a professional electronics laboratory, eager to train more theoretical knowledge is solid, hands-on ability of the talents, and further improve their employment rate and influence. Now, some schools have begun to build SMT laboratory, then, in the end, the school has no need to invest in the construction of such similar to the production plant laboratory? What is the significance of this? Schools to train electronic personnel since the electronics industry is to enter the industry, whether doing research or production, he must be subject to the actual ability to produce and the actual needs of the production, in line with the current development of the national SMT industry in the direction of the needs of the general direction. Then the school's training should also be closer to the actual production, so that students understand the production process and production technology, so our universities and colleges is necessary to build up their own SMT production line, can not let the students just paper, only with strong theoretical knowledge, but also excellent hands-on ability of the talents, is more suitable for the needs of society. We said earlier. First of all, the development of the electronics industry has always been in the direction of high integration, high reliability and high intelligence. As a result of the large number of highly integrated surface mount components, many of the circuit boards are not like before with a soldering iron and solder can be welded, many highly integrated components have to be welded with the help of special equipment and special tools, in order to meet the mass production of electronic products, new welding technology and welding process both SMT technology has been the rapid development. It is produced in the actual production of electronic products, and influence and guide the production of electronic products. All electronic factories need a large number of production process technicians and designers familiar with the production process, research and development personnel. Then the school should cultivate the talents that are lacking in the talent market and further improve the hands-on ability of students. This is also in line with the needs of the market. At present, our country, many laboratories and experimental classes are stuck in the soldering iron welding at the primitive level. Secondly, the electronic soldering process and technology also from a large extent restricts the development of China's electronics industry, if our electronic technology to catch up with Europe, the United States, Japan and South Korea and other countries, but also need a large number of technicians to understand and be familiar with the SMT technology, and continue to explore the work in the pragmatic to seek development from this point of view. Colleges and universities should, of course, by virtue of their strong technical capital, to become the vanguard of the promotion of sustainable development of China's electronics industry, but also more people should be more students to understand and familiar with SMT technology, which is also the need of the country and the nation. Therefore, it is necessary for colleges and universities to build SMT laboratories. From the current actual situation, colleges and universities to establish SMT laboratory is not only necessary, this demand is also very urgent. Now, the domestic SMT industry, most of the employment of talents are graduated and then enter the industry after learning, and basically electromechanical engineering, mechanical design, computer, microelectronics and other professional students. Many education experts pointed out that our current education system has not been able to closely match the demand for talent, at the same time, many students are rich in theoretical knowledge, poor hands-on ability. As a result, many employers can not find suitable talents, and many graduates can not find suitable units. The employment rate of many college graduates employment is decreasing year by year, many professional talents in excess, and now there are even many of the employment rate of technical school graduates than the employment rate of many college graduates is still high phenomenon. These issues are most colleges and universities want to solve the problem as soon as possible. Many schools have begun to adjust their specialties according to the demand for talent, and increase efforts to train students' hands-on skills. In terms of the SMT industry, there have been a lot of universities and colleges to build their own laboratories, opened the relevant courses. Only in this way can we improve the employment rate, ease the employment pressure, and train suitable talents for many employers. From this point of view, the establishment of SMT laboratories in colleges and universities is urgent. We believe that the establishment of SMT laboratories in colleges and universities will provide the electronics industry with a large number of more excellent technical personnel, will certainly play a driving role in China's electronics industry. The sustainable development of China's electronics industry has a strong guarantee.
Five: college SMT laboratory equipment needed!
Appendix 1: Introduction to the form of packaging from 1955 to the present day!!! The basic type of microelectronic packaging changes about every 15 years, from 1955 onwards is mainly TO-type round metal package, the package object is a transistor and small-scale integrated circuits, the number of package leads for 3 - 12 lines. Since 1965, the main dual in-line package (DIP), first ceramic DIP and then plastic DIP, the number of leads for 6 - 64. In 1980, the emergence of the surface mount package (SMT), the main form of package is SOP, SOT, SOJ, PLCC, PQFP and so on. The number of leads is 3 - 300. In 1995, the emergence of solder ball array (BGA) and chip size package (CSP), BGA of the outer lead for the solder ball, arranged at the bottom of the chip.CSP silicon chip area and the package accounted for by the ratio of the area of the printing plate is greater than 80, the outer lead can be the lead of the lead frame lead, the solder ball, or the solder bumps. It is now possible to make solder bumps directly on the individual chips of a silicon wafer, which are then cut into separate IC chips that can be directly flip-soldered.
Appendix II: high-density packaging Abstract: This paper introduces the microcircuit of several high-density packaging, focusing on today's most popular multi-chip package (MCP), the new system-on-chip (SIP) and three-dimensional packaging, and pointed out that this is a realization of the system-on-a-chip alternative. Keywords: packaging; high-density; multi-chip; three-dimensional
The driving force behind the rapid development of microelectronics technology is undoubtedly the everlasting requirement of small, light, portable, reliable and cheap electronic devices. History and reality have proved that: the realization of these requirements of the technical means, is undoubtedly to semiconductor integration, including design, manufacturing, packaging, testing, assembly, etc. as the core of the new technology, new materials, new processes continue to develop, and even revolutionary breakthroughs. Semiconductor integration technology has become the basis of microelectronics, is the most active and most vitality and exciting a branch; with the appropriate, microelectronics packaging has also become a fast-changing, thriving industrial sector. Microelectronic packaging has gone through an unusual history. Can be divided into four stages: the twentieth century in the seventies of the dual-row direct insertion (DIP), lead bonding, in the printed circuit board through the solenoid connection; eighties of the surface mount (SMT); nineties of the solder ball array (BGA), the recent in-shell system or system-in-package (SIP). There has also been a revolution in terms of concepts. Today, has evolved from the past simple package shell (PACKAGE) concept, and is an integral part of the package body, that is, to become an integral part of the performance of the semiconductor device - "package" has penetrated into the package body (known as PACKAGING). Imagine, about 30 years ago, a 64kb core memory about two refrigerators; and now 256Mb chip is only the size of a thumbnail. In the early days of a 25mm2 silicon chip only a transistor; today a 17mm2 silicon chip contains more than 50M transistor circuits. At the beginning, 12.7mm ceramic module has 16 pins, can only encapsulate a single transistor and a few thick film resistors; now multi-layer ceramic module is roughly 5 × 645.16mm2 or more, can contain 30 million - 50 million transistor chips and more than 3,000 pins. The earliest assembly boards were wire-wound double board pairs, and today there are more than 30 layers with several board pairs. Interconnect technology from the initial 16-pin 25mm pitch module to today's 32mm BG / L die lack of 1.27mm pin pitch and 42mm CGAR 1.00mm pitch, and CSP and micro BGA pin pitch is about 0.5mm.