PCB

 . Stands for Printed Circuit Board.
 . It is a thin board made of fibre glass, composite epoxy and other laminate materials.
 . Conductive paths are printed onto board which connects transistors, resistors and IC's.

Before PCB's:

 . Circuits were constructed through wiring and point-to-point connections.

 . It led to many failures at wire junctions.

 . Short circuits occurs when wire insulation began to age and crack.

Applications of PCB's:

 . Used in desktops, laptops.

 . Video cards, RAM, motherboard made of PCB's.

 . Also found in TV, radio, digital cameras, cellphones.

Advantages:

  . Compact size.

  . Components are fixed, they do not move.

  . Tight connections, short circuits are avoided.

  . Low radiation, low cross talk between components.

  . Layouts once designed can produce mass number of same type.

Disadvantages:

  . Increased design time.

  . Development cost.

  . Difficult to modify once board is fabricated.

  . Sensitive to handle.

  . Not easy to repair once damaged.