Topic 6- SMT

A surface mount component can be defined as any electrical components mounted on one or both sides of a PCB and interconnected to the copper tracks via a lap solder joint.
* Advantages: Smaller and lighter, higher quality assembles, lower overall costs.
*There are 3 different types of SM components.
1) Metal electrode face resistor diode
2) Small Outline transistors> 23(SOT) and 89(SOT)
3) Small Outline Integrated Circuits (SOIC) >Gull wing. J-Bend and I-Bend 
4_ IC(Memory devices)
5) Plastic Leaded Chip carriers
6) Lead-less Ceramic Chip Carriers(LCCC)
*6) is a method of mounting chips on boards using contacts instead of leg-like pins. The chip rests in a socket that has contacts on its base for completing the connections.

Static Electricity

*Objects are charged by adding or removing electrons
*Static charges are produced whenever there is friction between 2 materials or between human and material.
*Electrostatic discharge is a sudden discharge of stored up of static charges.
*It can cause rupture on materials inside devices.
*ESD devices can be damaged when in contact with skin.

Field Effect Transistor

*Semiconductor devices that control the flow of the current by an electric field.
* FETs are voltage operated device, and does not require input current.
* It has extremely high input impedance.

JFET-Junction Field Effect Transistor

* Available only as depletion mode type
* Insulated Gate type(IGFE9) 
(available as enhancement mode or depletion mode)
(metal oxide semiconductor (FET MOSFET))
(silicon-on- sapphire FET)
(Can be N-channel or P-Channel)

Inductor

*Made up of a coil of wire wound around a core.
*Tend to oppose the change of current flowing throughout.
*Also known as inductance
* Unit is Henry(H)
*Types of inductor: Air, Ferrite, Magnetic Dust and laminated iron
*Known as chokes or coils.
*It is to block noise or act as a filter.


Okay, let's stop for awhile now shall we?
This is the whole 2 pages.
I'm afraid there's 3 more to go..
So sorry.. Made a mistake ...
=)
Happy Reading / revising!
^_^||