First, the surface mount component classification
1. Interconnect: Provides mechanical and electrical connection / disconnection, consisting of connecting plugs and sockets, connecting cables, brackets, enclosures or other PCBs to PCBs; however, the actual connection to the board must be via surface mount Type contact.
2. Active electronic components (Active): In analog or digital circuits, you can control their own voltage and current to produce the role of gain or switching, that is, the response to the application of the signal can change their basic characteristics.
3. Passive electronic components (Inactive): when the application of electrical signals do not change their own characteristics, that is, to provide a simple, repeatable response.
4. Odd-form: The geometrical factor is peculiar, but not necessarily unique. So it must be manually mounted, its shell (in contrast to its basic function) shape is not standard, for example: many transformers, hybrid circuit structure, fan, mechanical switch block and so on.