PCB Image


Printed circuit board (PCB) 

1. Mostly electronic circuits are mounted on a plastic insulating board with printed wiring.

2. This is called 'printed circuit board (PCB) One side of a PCB has conducting paths printed with copper on the board, instead of using wires. 

3. The other side has the components, such as resistors, capacitors, coils, tubes, transistors, diodes, and integrated circuits (IC).


ADVANTAGES OF PCB OVER NORMAL WIRING ARE 

1. PCBs are useful for mass production.

2. Small components can be easily mounted on PCB.

3. PCBs are useful for interconnecting a large number of components in a very small area.

4. Construction is neat, small and a work of art.

5. Servicing becomes easier.

6. The electronic equipment becomes more reliable, small in size and cheaper


MATERIALS USED FOR PREPARING PCB 

1. The base materials used for PCB use paper phenolic, glass epoxy, epoxy paper and polyester etc. 

2. Paper phenolic is cheaper and used in consumer electronics circuits.



TYPES OF PCB

(1) Single sided PCB. 

(2) double sided PCB.

(3) multilayer PCB.

(4) flexible PCB.


Types of PCB

1. Single sided PCB  

a) In this type, the copper tracks run only on one side of the copper clad board. 

b) This type is used in radio receivers, TV etc.


2. Double sided PCB 

a) In this type, copper foil is present on both sides

of the copper clad laminate.

b) The components are mounted on both sides.

c) Large numbers of components can be mounted. 

d) This type is used in microprocessors, CRO etc.


3. Multilayer PCB 

a) These are used in high interconnection density applications. 

b) In these boards multiple insulated wires are used for interconnection. 

c) For connecting external components, plated through holes are used. 

d) Wiring can be done on both sides for more number of connections.


4. Flexible PCB 

a) These use a special base material which can be folded.

b) These are used in military and air space applications and computers. 

c) For production of a few printed circuit boards manual or laboratory method is used.

d) For mass production industrial photo resist methods are used.