1. (Printed Circuit Board) Presented By S.Muthumari
PCB
(Printed Circuit Board)
Presented By
S.Muthumari

2. Content PCB Bread Board Thickness of copper Types Manual printing
Photo resist method
Screen printing method
Using software
Etching process
Schematic diagram
layout

3. Difference between PCB Layout and bread board connection

4. Bread board ADVANTAGES: DISADVANTAGES:
1. A QUICK CHECK FOR EASY AND COMPLEX CIRCUITS BOTH AND VERIFIES CIRCUITS AT INITIAL STAGE.
2.REUSABLE.
3.NO SOLDERING REQUIRED.
4.CAN BE DEBUGGED EASILY.
5.CHEAP AND CONNECTIONS CAN BE CHANGED.
DISADVANTAGES:
1. UNRELIABLE.
2. DELICATE.
3.TEMPORARY.
4.HEAVIER.

5. PCB There are subdivided into,
A printed circuit board, or PCB, is used to mechanically support and electrically connect electronic components using conductive pathways, tracks or signal traces etched from copper sheets laminated onto a nonconductive substrate. It is also referred to as printed wiring board(PWB) or etched wiring board. Printed circuit boards are used in virtually all but the simplest commercially produced electronic devices.
Components used for PCB
Copper cladded sheets
There are subdivided into,
paper phinally
glass epoxy

6. Advantages of PCB Inexpensive/cheaper High volume production
Automated soldering is possible
Highly reliable
Hold the component easily

7. Thickness Of Copper
0.8mm(used for low power component( e.g.: slim phone,smd,multimeter)
1.6mm(used in commercial purpose)
3.2mm(power electronics side
Examples: MOSFET, Diode.

8. Types Manual printing. Photo resist method. Screen printing
Using software

9. Manual printing Get the required size copper board.
Draw the layout on the board using permanent marker or nail police.
Etching process.
Fix the component on the board
Check the output

10. Photo-resist method
The main properties characterizing the photo resist types are:
Photo resists are classified into two groups: positive resists and negative resists
positive resist method
negative resist method

11. Positive resist method
A positive resist is a type of photo resist in which the portion of the photo resist that is exposed to light becomes soluble to the photo resist developer. The portion of the photo resist that is unexposed remains insoluble to the photo resist developer.
Negative resist method
A negative resist is a type of photo resist in which the portion of the photo resist that is exposed to light becomes insoluble to the photo resist developer. The unexposed portion of the photo resist is dissolved by the photo resist developer.

12. Characteristic Positive Negative
Adhesion to Silicon Fair Excellent Relative Cost Less Expensive Developer Base Aqueous Organic Minimum Feature μm and below ± 2 μ step Coverage Better Lower
Wet Chemical Resistance Fair Excellent 

13. Exposing Sun light (minimum 3 mins) Mercury lamp(8 mins)
Tube light (15mins)

14. Screen printing
Screen printing printed circuit boards is typically performed in a clean, dust free room using semi-automatic or fully-automatic screen printing presses. The most common PCB panel size is 53 x 72 cm, with the printing area around 50 x 70 cm. The printed panel may contain many PCB panels that are printed at once, and will eventually be separated.

15. 1.4 Soldering Methods
Hand soldering: It is the oldest method of soldering, it is still popular method in certain kinds of applications: Development of prototype boards
Low volume production
Soldering of extremely temperature sensitive components
Solder reflow of fine pitch components using hot bar
Rework or repair of machine soldered boards
The main disadvantages are operator training, speed, and consistent quality. 

16. 1.4.2 Machine Soldering: Two prominently used machine soldering types are: A. Wave Soldering
Primarily used for soldering through-hole components on to PCBs.
B. Reflow Soldering.
Used for soldering SMD components on to PCBs. Reflow soldering of SM components have the following advantages over manual soldering:
Mass soldering
Consistency in manufacture through precise control of process parameters.
flexible for small production runs as well.

17. Etching process Fecl3+cu->cucl3+fe
The following are used for etching
HCL
Cupric chloride
Ferric chloride
Ammonium chloride.
Fecl3+cu->cucl3+fe

18. Method of etching
Hand drought method
Splash method
Spray method

19. Solder mask Solder mask is used to prevent oxidization
solder able solder mask
Un solder able solder mask

20. Why masking?
a. Protect tracks from environmental effects suc as corrosion
b. avoid between two electrical components during soldering, testing.
c. Protects PCB material from environmental effects.

21. Plating To avoid corrosion brightness easy solder able
deposit harder than ordinary plating
corrosion resistance
non-staining
non-toxic

22. Software
Eagle version (Easily Applicable Graphically Layout Editor)
PCB Wizard
Pad2pad
Spark PCB

25. Schematic Diagram

26. Layout

27. SMD Component Layout

28. THANK YOU ?