In the context of IPC-A-610, what does “tinning” refer to?

In the context of IPC-A-610, “tinning” refers to the process of coating a metal surface with a thin layer of solder. This technique is an essential preparation step in soldering, as it enhances the solderability of the metal surfaces and helps ensure a strong and reliable electrical connection when soldering components onto a printed circuit board (PCB).

By applying a thin layer of solder, known as tinning, you create a more favorable surface for solder to adhere to, reducing the chances of cold solder joints and improving the overall quality of the connection. Furthermore, tinning protects the underlying metal from oxidation, which could impede electrical conductivity and negatively affect the assembly's performance over time.

The other choices, while related to electronic assembly processes, do not accurately define tinning. Painting a circuit board, cleaning metal surfaces, and applying a protective coating after soldering are distinct processes that, while important, do not encompass the specific definition and function of tinning within the context of IPC-A-610.