PCB

Shweta jadhav

A PCB is a printed circuit board, also known as a printed wiring board. It is used in electronics to build electronic devices. A PCB serves two purposes in the construction of an electronic device; it is a place to mount the components and it provides the means of electrical connection between the components.

Conducting layers are typically made of thin copper foil.

The board is typically coated with a solder mask that is green in color. Other colors that are normally available are blue and red.

Unwanted copper is removed from the substrate after etching leaving only the desired copper traces or pathways

Components Pads Traces Vies Top Metal Layer Bottom Metal Layer

Components are the actual devices used in the circuit.

This includes input/output connections.

I/O ports, including power supply connections, are also important in the PCB design.

The PCB needs to be mechanically secured to something.

Could be the chassis-consist of metal frame on which the circuit boards and other electronic components are mounted.

Could be another PCB/socket on PCB.

Could be attachments to a heat sink.

High frequency circuitsSeries InductanceShunt CapacitanceInductive CouplingCapacitive Coupling

Steps in PCB design process

1. Film Generation

2. Shear Raw Material

Industry standard 0.059" thick, copper clad, two sides

3. Drill Holes

4. Electrolux copper

Apply copper in hole barrels

5. Apply Image

Apply Photosensitive Material to develop selected areas from panel

6. Strip and Etching

•Remove dry film, then etch exposed copper

•Tin protects the copper circuitry from being etched

7. Solder Mask

Apply solder mask area to entire board with the exception of solder pads

8. Solder Coat

Apply solder to pads

9. Silkscreen

Apply white letter marking using screen printing process