You may don't know the really PCB components!

From:http://www.htdcircuits.com/pcb-components-assembly-on-the-surface-of-the-printed-circuit-board.html

This post topic is PCB components.
In fact this is another area of electronics.
But it related to the PCB industry.
And some of customers ask questions about a PCB component.

First is the PCB component definition.
PCB components assembly on the surface of the printed circuit board.
And its function is let PCB assembly to PCBA.
Then you can produce the end products.
So PCB components were part of PCBA or electronic products.

Then let begin to discuss the terms of use PCB components.
You know the PCB is just end step product.
So if there were no components on it.
The PCB has no function.
So the PCB components are use end of the PCB.
And most of PCB component assembly on the surface of the PCB.
After the printed circuit board (PCB) is completed, electronic components must be attached to form a functional printed circuit assembly or PCA.

The third factor is the assembly method of the PCB components.
You know the PCB components have many kinds of types.
In fact in old PCB assembly times, all the PCB component by people handle.
But after there was PCB stencil appears.
So most PCB companies use PCB stencils to assembly PCB components.
Back to assembly method of the PCB components.
In through-hole construction, component leads are inserted in holes.

Then the assembly place of PCB components.
You may know the all PCB component assembly on the surface of the boards.
In surface-mount (SMT - surface mount technology) construction, the components are placed on pads or lands on the outer surfaces of the PCB. 
In both kinds of construction, component leads are electrically and mechanically fixed to the board with a molten metal solder.