SMT chip processing reflow soldering method is introduced:

Infrared reflow soldering heating method and its advantages and disadvantages: Radiation conduction: high thermal efficiency, large temperature steepness, easy to control the temperature curve, easy to control the upper and lower temperature of the PCB during double-sided soldering. There is a shadow effect, the temperature is uneven, components are easily formed or the PCB part is burnt out. Hot air reflow soldering: the propagation conduction temperature is average, and the soldering quality is good.

SMT chip processing reflow soldering temperature gradient is not easy to control forced hot air reflow soldering: infrared hot air mixing heating separates the advantages of infrared and hot air furnace, when the product is soldered, it can get excellent soldering effect, forced hot air reflow soldering, according to its consumption ability and divided into Two types: Temperature zone type equipment: suitable for mass production. Suitable for mass production. The PCB board is placed on the conveyor. It must pass through a number of fixed temperature zones. If the temperature zone is too few, there will be a temperature jump phenomenon, which is not suitable for assembly of the board. welding. Moreover, it is bulky and consumes high power.

Small-scale desktop equipment without temperature zone: suitable for rapid research and development of small and medium-sized batches of production. In a fixed space, the temperature changes with time according to the set conditions, and the operation is cumbersome, especially suitable for BGA QFP PLCC. It can stop repairing defective surface mount components (especially large components). It is not suitable for mass production. Due to the "re-activity" and "self-positioning effect" characteristics of the reflow soldering process, the reflow soldering process has relatively loose requirements for placement accuracy. It is relatively easy to complete the welding with a high degree of automation and high speed.

At the same time, due to the characteristics of reactivity and self-positioning effect, the reflow soldering process has stricter requirements for pad design, component standardization, component tip and printed board quality, solder quality, and process parameter settings. Cleaning is the process of applying physical action and chemical reaction to remove contaminants and impurities on the surface of the object to be cleaned. Whether it is solvent cleaning or water cleaning, it must undergo surface wetting, dissolution, emulsification, saponification, etc., and apply different methods of mechanical force to peel off the dirt from the surface of the exterior assembly board, and then rinse or rinse to clean. Blow dry, dry or dry naturally.

SMT chip processing is a key process in the production of reflow soldering. A reasonable temperature profile setting is the key to ensuring the quality of reflow soldering. Inappropriate temperature curve will cause the PCB board to show soldering defects such as incomplete soldering, false soldering, component tilting, and excessive solder balls, which will affect the quality of production.