A printed circuit board holds electronic components together and provides electrical connections between them. It has a copper layer that forms the electrical pathways and a fiberglass layer that provides mechanical strength. Components can be mounted on the surface or inserted through holes. Traditionally, etching liquid was used to remove copper from PCBs but this is a slow, inaccurate, and environmentally harmful process. Now, CNC milling is used which is faster, more accurate, and eco-friendly as it requires no chemicals. The PCB design process involves creating files, converting them for CNC use, milling isolation paths, drilling holes, mounting components, and soldering connections.

1.  A printed circuit board, or PCB, is what holds your
electronic components together and also gives electrical
paths for their interconnection.
 PCB boards usually have copper base for the electrical
paths known as the copper layer.
 The other side is usually fiberglass, composite epoxy, or
other laminate material that gives good mechanical
strength to the PCB.
 The components can be mounted in through hole fashion
as well as in surface mount depending upon what
component type we will use like SMD, DIP, etc.
Printed Circuit Board

2. The traditional Method
– Using Etching Liquid
Is Slow
Is Not Accurate- Some unwanted copper may be left out

3. Liquid needs special disposal after use
Disposing the copper liquid in normal sewage is a Legal Offence
Disposing of Etching Liquid Is Illegal

4. Requires Harmful Chemicals- May lead to Hand Burns
Is not Eco Friendly

6. Is Fast
Extremely Accurate
Is Eco Friendly
No Chemicals Needed
PCB Milling

7. Steps of PCB designing
PCB files creation
Loading CNC files
Isolation Milling
Drilling
Component Mounting
Soldering
PCB DESIGNING

8. 1. PCB files can be created using various software available in the market of
which some are free while the others being needed to be purchased.
2. Some of the software names are as Eagle PCB, Proteus, Easy PCB, etc.
3. The design stuff can be done using these software’s layout explorer
features.
4. The second step will be creating CNC readable files. The file format
generated by the earlier software is usually not understandable by the CNC
machine’s software.
5. Hence, here we have an in intermediary software like CopperCam that
converts these file formats into the ones readable by the CNC machine’s
software.
6. The copper layer file and the drill layer files are separately generated by
the software.
7. Once the CNC readable files are generated, they can be uploaded to the
CNC software (CNC software comes with the machine itself and is
recommended by its manufacturer).
PCB Files

9. 1. The CNC software just requires the CNC files as input and when these files are
loaded, the machine is ready to go.
2. Using the CNC software we can adjust and configure the milling reference points
and the speed at which the work will be done.
3. For creation of tracks isolation milling is carried out using milling bit.
CNC Software

10. 1. After milling has been done, the bit changed from milling bit to drill bit.
2. Then the other file is loaded in the CNC software to carry out the drilling of holes
for mounting of components on the PCB.
3. Once the holes are made we are ready to mount the components and solder them.
CNC Software

11. 1. The components which are DIP type needs holes in the PCB.
While SMD components can be directly mounted and soldered
on the surface of the PCB.
2. We usually deal with DIP components as they are easy to use
while making a less densely populated PCB
3. So now we insert the components and then solder them one
by one.
4. The final PCB made looks as in the following slides.
5. The side where soldering is done is Copper side.
6. The side opposite of Copper side is Silk Screen Side.
Components Mounting

12. PCB Copper Side

13. PCB Silk Screen Side

14. Thank You