During the PCB assembly process, chemical reactions are usually not required. PCB assembly mainly realizes the manufacturing and assembly of circuit boards through physical means, such as mechanical processing, welding, connection, etc. These methods usually do not involve chemical reaction processes.
However, in some cases, chemical processing may be used to prepare or post-assemble PCBs. For example, in the process of making a PCB, chemical etchants may be used to create circuit patterns. In addition, after assembly, chemicals may be used for cleaning, protection or surface treatment. In these cases, although chemical processing processes are involved, they are usually not the primary means of PCB assembly.
In short, PCB assembly is mainly achieved through physical means and does not involve chemical reaction processes. However, in some cases, chemical treatment processes may be used for preparatory or post-processing purposes.