Can be high density. For decades, the high density of printed boards has been able to develop along with the improvement of integrated circuit integration and the advancement of mounting technology. High reliability. Through a series of inspections, tests and aging tests, the PCB can work reliably for a long period of time (usually 20 years). Designability. For PCB performance (electrical, physical, chemical, mechanical, etc.) requirements, printed board design can be achieved through design standardization, standardization, etc., with short time and high efficiency. Producibility. With modern management, it can be standardized, scaled (quantified), automated, etc., to ensure product quality consistency. Testability. A relatively complete test method, test standard, various test equipment and instruments have been established to detect and appraise the eligibility and service life of PCB products. Can be assembled. PCB products are not only convenient for standardized assembly of various components, but also for automated and large-scale mass production. At the same time, PCB and various component assembly parts can be assembled to form larger parts, systems, and complete machines. Maintainability. Since PCB products and various component assembly parts are designed and produced on a large scale, these parts are also standardized. Therefore, once the system fails, it can be replaced quickly, conveniently and flexibly, and the system can be restored quickly. Of course, there can be more examples. Such as miniaturization and weight reduction of the system, and high-speed signal transmission. International situation The global PCB industry output value accounts for more than a quarter of the total output value of the electronic component industry, and it is the industry with the largest proportion among the various electronic component industries, with an industry scale of 40 billion US dollars. At the same time, due to its unique position in the electronic basic industry, it has become the most active industry in the contemporary electronic component industry. In 2003 and 2004, the global PCB output value was 34.4 billion US dollars and 40.1 billion US dollars, with a year-on-year growth rate of 5.27%. And 16.47%. Development status of domestic PCB industry my country's PCB research and development work began in 1956, and gradually expanded to form the PCB industry from 1963 to 1978. After more than 20 years of reform and opening up, due to the introduction of foreign advanced technology and equipment, single-sided, double-sided and multi-layer boards have achieved rapid development, and the domestic PCB industry has gradually developed from small to large. Due to the concentration of downstream industries and the relatively low cost of labor and land, China has become the region with the strongest development momentum. In 2002, it became the third largest PCB producer. In 2003, PCB output value and import and export value both exceeded US$6 billion, surpassing the United States for the first time and becoming the world's second largest PCB producer. The proportion of output value has also increased from 8.54% in 2000 to 15.30%, which has nearly doubled. In 2006, China replaced Japan as the world's largest PCB production base and the most active country in technological development. my country's PCB industry has maintained a rapid growth of about 20%, which is far higher than the growth rate of the global PCB industry. From the perspective of output composition, the main products of China's PCB industry have shifted from single-sided and double-sided boards to multi-layer boards, and are increasing from 4 to 6 layers to 6 to 8 layers or more. With the rapid growth of multilayer boards, HDI boards, and flexible boards, the structure of my country's PCB industry is gradually being optimized and improved. However, although my country's PCB industry has made great progress, there is still a big gap compared with advanced countries, and there is still much room for improvement and improvement in the future. First of all, my country entered the PCB industry relatively late, and there is no dedicated PCB research and development institution, and there is a big gap between the R&D capabilities of some new technologies and foreign manufacturers. Secondly, from the perspective of product structure, the production of medium and low-layer boards is still the main product. Although FPC and HDI have grown rapidly, their proportion is still not high due to their small base. Third, most of my country's PCB production equipment relies on imports, and some core raw materials can only rely on imports. The incomplete industrial chain also hinders the development of domestic PCB series enterprises.