Welcome back mates.
This is your favorite captain aboard
Captain Jack
In the last lecture we saw different layers in the PCB and today
we'll see how we can view or toggle these layers in Proteus
So let's get started
First of all I'd like to introduce you to my unique controller board
The curiosity board. It's the teaser of one
of the designs
we are going to study under the
micro-controllers
This board has almost all the layers
that we need to understand
we may not go in the same sequence as we
had in the theory lecture but
always the first things first and we are
going with
Oh wait wait wait
let's not get out of track
and
Let's start with the mechanical layer
The mechanical layer acts as the foundation of the PCB
Just like the foundation of a house
In Proteus it is denoted by yellow color
and it is also known as the board edge
We can see over here in
the bottom left
the yellow color represents the board
edge
Then how could how could we make this
mechanical layer
So these 2D graphics buttons are used
for making the mechanical layers
So we have line mode
The box mode, the circle mode, the arc
mode
and a closed path which can give any
shape any abstract shape that you want
Then the same buttons can be used for
making of the keep-out layer
That's the second layer that we had
studied
This layer is denoted by the red color
Instead of making that layer i will just change this layer
by right clicking on it
change layer and keep keep out layer
so the keep out layer is made
is denoted by the red color
this layer is necessary when the board
is going to be covered by a container
that will be covering a part of the PCB
or a similar restraints in the product
so to avoid overlapping of the parts on
the circuit we can make the keep out layer for
the designer to understand
that the components should be placed
inside this layer
then the important layer that is responsible for the electrical connectivity
over which the tracks and the planes are
laid is the copper layer
This layer
is in the form of a foil that is placed
even in between
the layers of of the board which is fr4
So that the tracks and planes can be
generated over there too
Over here we can see that the top copper
is represented
by something like a deep red color       
over here after we select top copper
and over here this cursor is selected
so the top copper is denoted by
something like deep red
and the bottom copper is denoted by a
deep blue color
So after I have selected the cursor
now when I hover my cursor over the
circuit almost everything is selected.
So to avoid this we have
these options over here
we can use layer filter mode to select
only the layer that has been marked so
I can move over the top copper and only
top copper is highlighted
To avoid the selection of the plane
I can select this one or deselect this
one
and even when I hover my mouse over the
plane
the top copper plane is not selected
similarly we can do with the components
we can do with the
pins, tracks we can do it with the wires
and so on
So after the copper top copper layer
The bottom copper layer the most basic
layers we have
other layers as I had said we can design 16
layer PCBs in produce so over here
In this option in the display settings
we can change the
display options we can change the color
that is used to represent so
here is the top copper here is the
bottom copper and these 14
inner layers are used for the other
inner copper layers
So I suggest to keep all
the settings to be default
and do not mess with them and we can do
the designing as per our needs
after the selection of the the copper
layers
we have the plane so
when we click on this planes option we
can select whichever plane we want like
the top plane or the bottom
now or now you can see that
both the planes are made of copper
itself so that's why
the top copper and the top plane
is of the same color as well as the
bottom copper and the bottom plane is of
the same color
now the most the top most layer
in a PCB is always the silk layer which
is used to denote the components
or the various labels like I have named
my board
So the name of my board is in the
is the bottom silk layer so we can see
over here the bottom silk is denoted
by pink and the top silk is denoted by a
cyan color which is the greenish blue
tinge so now if you observe the
top silk is is not a mirrored image it's
directly like we can read it processor
but the bottom bottom silk
is uh has to be made a mirror image
because
if it is at the bottom and we are seeing
from the top it obviously
has to be a mirror image so now we'll go
to the 3D visualizer
so that we can actually visualize these layers
and some other layers that are remaining
so we can see the bottom
the bottom silk layers the curiosity board
you can see is straight and
the naming of the components
so now the fr4 layer which was not
visible in the
pcb layout we can see over here in
between
this line this represents the fr4 layer
and now the solder mask now
Typically
the solder mask is of green color but to
understand better
what we do is we go into templates in
Proteus the solder mask
is shown by the resist option so
we'll make this resist completely
transparent
and then we should be able to observe
the copper beneath it
so usually as i said the solder mask or
the resist is of green color
apart from making the board attractive to
impress... whoever came to mind first ;)
the importance of this layer
is that it provides isolation to the
copper layers from the external
environments it stops any external noise
from being included and also prevents
short circuiting
so if we remove the solder mask this is
how our
copper planes would be vulnerable to
the external environment so to avoid
this
the resist layer is has to be applied
so that's all about the various layers
of a pcb
in the next video we'll study about the
selection criteria of the tracks in PCB
till then take care and
Miss your favorite captain fellas
