With the rapid development of electronic components, the requirements for miniaturization and integration of electronic systems are becoming increasingly high, and the trend of electronic products is constantly transforming towards miniaturization and SMT. In surface mount technology, various defects in the welding process of surface mount components often lead to substandard electronic product quality. The level of welding process determines whether the quality of electronic products is qualified.

The crystal components developed by utilizing the electrical properties (piezoelectric and piezoelectric phenomena) and optical properties of crystals are an indispensable and important part of electronic products. According to their different characteristics and functions, crystal components can be roughly divided into three categories: timing components, sensing components, and optical components. At present, these crystal components are widely used in fields such as mobile phones, consumer electronics, computers and peripherals, automotive electronics, and communication base stations.

Surface mounting technology, abbreviated as SMT. For the welding method of SMT crystal oscillators, surface installation technology is a necessary skill to master. It includes two types: surface mount component (SMC) and surface mount component (SMD). SMD direct mounting on printed circuit boards, the assembly and welding technology on the surface of PCBs, is a systematic and comprehensive technology that integrates electronic components, circuit design, assembly equipment, assembly process, welding methods, and other aspects of the PCB substrate. It has the characteristics of high miniaturization, good high-frequency characteristics, low cost, high automation, high production efficiency, and high reliability of electronic products.

There is an important parameter in SMT crystal oscillators, which is the reflow soldering temperature. Here, we will discuss the technology and characteristics of reflow soldering. Reflow soldering technology is mainly used to complete the automatic soldering of SMT components. It processes the solder into particles of a certain size and mixes them with appropriate adhesive to form a paste with a certain fluidity. The SMT crystal is attached to the PCB board by the solder paste, and then the solder in the solder paste is melted and flows again by heating. The characteristics of reflow soldering technology are to solder SMT components to the PCB printed board.

1. Reflow soldering uses local heating instead of immersing the PCB printed board in molten solder, thus avoiding damage to the crystal oscillator caused by overheating.

2. Reflow soldering only requires the application of solder at the welding site and local heating to complete the welding, avoiding welding defects such as bridging.

3. In reflow soldering, the solder is used once, so the solder is pure and free of impurities, ensuring the quality of the solder joints.

To produce high-quality electronic products, having advanced SMT hardware equipment alone is not enough. The key factor is whether the equipment can be used and adjusted reasonably and correctly. Reflow soldering is a complex and critical process in the assembly of SMT printed circuit boards during the use of crystal oscillators. There are many factors that affect the reflow soldering process. To achieve excellent soldering quality, it is necessary to conduct in-depth research on various problems that arise