Through hole instrumentation technology is a classical method for infrared PCBA fabrication. It starts by drilling holes in the PCBA, where the positions of the holes correspond precisely to the component pin layout. Then, the pins of various types of electronic components are inserted into the corresponding holes. Discrete components such as resistors and capacitors can be inserted manually, while complex components with multiple pins need the help of specific tools. After the insertion is completed, the pin and pad are soldered firmly on the back of the PCBA using a welding device, such as a soldering iron, to form a reliable connection. Finally, through manual inspection or automatic optical inspection (AOI) equipment, the welding quality and installation position of components were comprehensively checked to ensure that the PCBA met the quality requirements. This technology is very advantageous for the installation of some large, heavy and high mechanical stability components on PCBA, and is still widely used in the production of PCBA in industrial control equipment and other fields.

Surface mounting technology

Surface mount technology has become one of the mainstream methods of modern PCBA fabrication. The process begins with the solder paste printing process, where the solder paste is accurately applied to the pad position on the PCBA surface with the help of a steel mesh. Then, the surface mount components (SMC/SMD) are picked up and placed on the corresponding pads with high speed and accuracy by the mounting machine. The high speed and accuracy of the mounting machine greatly improve the production efficiency. After that, the PCBA with the components mounted is sent to the reflow soldering furnace, and the solder paste is heated and melted in the furnace, so that the pins of the components are closely combined with the pads. After welding, the PCBA should be cleaned to remove residual flux and other impurities according to the situation, and AOI equipment should be used again to carefully check the accuracy of component placement and the quality of solder joint. This technology can realize the high-density assembly of components on PCBA, effectively reduce the volume and weight of PCBA, and occupy a dominant position in the field of PCBA production of consumer electronic products such as mobile phones, tablets and so on.

Hybrid assembly technology

Hybrid assembly technology combines the advantages of via instrumentation technology and surface mount technology. In the design phase, the layout of the components on the PCBA is carefully planned according to the characteristics of the components, such as type, size, electrical performance, etc., to clearly distinguish which components are suitable for through-hole instrumentation and which are suitable for surface mount. Then, SMT components were assembled according to the process of surface mount technology, including solder paste printing, component mount and reflow soldering. Then the THT element assembly is completed by drilling, element insertion and welding according to the steps of through hole instrumentation technology. During the whole process, special attention should be paid to the compatibility and operation sequence of the two assembly methods to avoid damage to the installed components. Finally, a comprehensive quality inspection was carried out on the assembled PCBA, covering electrical performance test, functional test and other aspects to ensure that the entire PCBA could operate stably and efficiently. This technology is often used in the PCB production of electronic products with complex functions and high reliability and performance requirements, such as high-end server motherboards, complex industrial automation control boards, etc.