Electronic assembly technology advances alongside electronic device packaging technology. The type of device packaging dictates the assembly technology; in other words, the packaging form of electronic components determines the assembly process. I. Origins The invention of the vacuum tube heralded the birth of a new industry, leading humanity into a new stage of development. Rapid advancements in electronic technology began, ushering in the electronic age. Initially, vacuum tubes were mounted on tube sockets, which in turn were mounted on metal base plates. Assembly involved connecting the device and the tube socket using discrete leads. Neat wiring and bundling of these leads ensured a clean overall trace. The high-voltage operating requirements of vacuum tubes necessitated greater attention to the routing of high-voltage and signal circuits, as well as personal safety during production. In 1947, Bell Labs in the United States invented the semiconductor point-contact transistor, ushering in the silicon age. The emergence of semiconductor devices and the application of low-voltage transistors not only changed people's lifestyles but also propelled humanity onto the fast track of high-tech development. Transistors with leads and metal casings, along with miniaturized passive devices with leads, laid the foundation for integrating several related circuits onto a single board. This led to the development of single-sided printed circuit boards (PCBs) and planar wiring technology. Assembly processes emphasized manual soldering of individual PCBs, significantly reducing the size of electronic products. With continued technological advancements, semi-automatic insertion technology and dip soldering assembly processes emerged later in this period, greatly improving production efficiency compared to earlier stages. II. Development Process In the 1970s, with the miniaturization of transistors into plastic packages and the application of integrated circuits and thick-film hybrid circuits, electronic devices saw the emergence of dual in-line packaged metal, ceramic, and plastic packages, as well as DIP and SOIC plastic packages. This further miniaturized passive components and led to the development of double-sided PCBs and the initial development of multilayer PCBs. Assembly technology also evolved to employ fully automated insertion and wave soldering techniques, and circuit lead connections became simpler. Since the 1980s, with the continuous development of microelectronics technology and the emergence of large-scale and very large-scale integrated circuits, the integration density of integrated circuits has increased dramatically, and computer-aided design techniques have been adopted for circuit design. As electronic technology has advanced, different packaging methods have dominated different periods. For example, in the 1980s, the advent of large-scale IC devices like microprocessors and memory led to the dominance of surface-mount plastic packages with peripheral leads and short pins, meeting high-speed and high-density requirements. In the 1990s, the development of very large-scale ICs and system-on-a-chip (SoC) propelled peripheral leads towards surface-mount array (SGA) and ball grid array (BGA) packages, making them mainstream. Passive devices evolved into surface-mount components (SMCs) and continued to miniaturize, leading to surface-mount devices (SMDs) for IC packaging. During this period, SMDs saw significant development, resulting in ball grid array (BGA), chip-scale package (CSP), high-density, high-performance, low-cost flip-chip, and multi-chip module (MCM) packages. Assembly technologies included surface mount technology (SMT) and reflow soldering and wave soldering, continuing towards narrow and ultra-narrow pitch SMT. All of these advancements have resulted in more advanced packaging technologies, with the chip area to package area ratio approaching 1, higher operating frequencies, better temperature resistance, increased pin counts, smaller pin pitches, improved reliability, and greater ease of use. Currently, we are in the period of popularization and application of this technology. With the continued development of microelectronics technology, the performance of devices, such as speed and delay time, places higher demands on the interconnection between devices. Due to the increasing influence of interconnect signal delay, crosstalk noise, inductive-capacitive coupling, and electromagnetic radiation, functional circuits composed of high-density packaged ICs and other circuit elements can no longer meet the requirements of high performance. At present, electronic components are increasingly developing towards chip-based, miniaturized, composite, modular, and substrate-integrated designs. IC packaging is evolving from single-chip QFP and BGA to CSP, wafer-level packaging (WLP), and system-in-package (SIP). Passive devices have evolved from surface mounting of individual devices to integration of several identical passive components (IPD), realizing a leap from 2D planar design to 3D three-dimensional spatial design. This results in smaller device package sizes, simpler product PCB design, and the achievement of higher speed, higher density, and lower cost requirements. We eagerly await all of these developments. III. Significance of Development With the continuous development of device packaging technology, our electronic assembly technology is also evolving rapidly. This constant evolution not only improves the performance and functionality of electronic products, making them thinner, smaller, and lighter, but also significantly improves their reliability and reduces assembly costs by decreasing the number of soldered components. Of course, new technologies require a series of new materials, technologies, processes, and equipment, such as new assembly processes and corresponding production equipment, testing processes and equipment, rework processes and equipment, wiring CAD/simulation programs, etc.