- [Instructor] Design rule checks are a critical component
in our PCB design, as they're gonna check
for any potential issues or errors or warnings
within our designs, and let us know how we can improve
or get rid of these issues.
So let's take a look at running through
some design rule checks here.
First I just want to go to my home tab.
The middle here I have design rules.
So I have a number of options here,
I can set up my design rules as we're gonna see
and I can also run a design rule check
which is gonna run through and show me where
any potential issues or violations may occur.
So I'm gonna hit rules and violations here.
And I'm gonna get this message window popping up here,
and I can dock it or move it to where ever I'd like.
Maybe I'll throw it on my right hand side here.
So this is just letting me know that right now
I've placed all my components somewhere
about where I'd like them and so on.
I haven't done the routing yet but we'll get to that
in a second, and it's just telling me here
if it's seeing any potential issues so far.
And usually you run your design rule checks
close to the end of a project,
but in many cases you're gonna run them
a whole number of times throughout a project.
You'll work on it for a little while
then run your design rule check or DRC,
fix up some potential issues, work on it some more,
run another DRC, fix up any issues and so on.
So it's kind of a iterative process there.
But definitely at the end before manufacturing
or finishing off a project, you're gonna wanna run
those design rule checks as well.
But so just running right now I'm seeing
I get a quite a few potential violations here.
And I can actually run through each potential issue
that I might run into here,
and see if I might have some issues here.
So most of these I'm seeing are empty,
but if you take a look here when I get to
clearance constraint, it's telling me my current
clearance constraint, electrical clearance here is 10 mil.
But right now it looks like I have about 18 violations
of this, so it's telling me that my current clearance
is even without any traces or anything like that,
just pads and things, I have a few clearances
that look to be about nine mil or so
or something less than 10 mil which I've set as my rule
in this case, for this specific project.
I can actually click on any of these potential issues here,
and it's also telling me which component
and everything like that.
So right now it's telling me that component U1
is having some issues with the pads here.
Looks like some of them are nine mil or so
or a little bit less than 10 mil.
So I'm getting an error, a warning here
saying that the minimum electrical clearance
that I've asked for here is 10 mil
and this U1 component actually has some clearances
that are below that.
So then it's up to you of course as the designer
or the engineer to see this information and do with it
what you will.
So if that may mean changing your design rule checks.
For example you think okay, I actually don't need 10 mil,
I only need eight mil clearance or five mil clearance
or something like that,
you can make those changes to your design rule checks.
Or you can see here maybe you need to re-route
some traces, if there was a trace issue
or if it's a component or pads are too close
or something like that.
If that were to ever occur you could maybe look
for a different component, or whatever it may be,
you as the designer or engineer are gonna be the one
who has to fix these issues up.
Again, generally your design rules and violations
or rules and checks would be set up initially
in a project.
Maybe even again as a project template
or something like this, and then you'll run it through
your entire project to see where issues may occur.
Let's take a look, we have anymore issues here.
Another one I think I have here
is silk to silk clearance constraint.
And again I can take a look at some of these.
So this is just telling me here that I have
some collision on my silk screens here.
And I can see that here, so just overlaps of my
silk screen information here.
Now this one's fairly simple to fix up.
I could just move where my labels are being placed
or something like this, and that should get rid of
some of my violations here.
So those ones are fairly easy to fix up.
And you can see pretty much automatically
as I'm fixing these up, I've just gone down
from seven violations to five violations here.
So I'm fixing those potential issues.
But if I want to make a change to some of the
design rule checks, let's say instead of 10 mil clearance
I want a eight mil clearance or something like that,
I'm just gonna close out of this,
and I'm gonna go into my design rules.
Again within the home tab, design rules
and this design rules manager right here.
So here I'm just gonna set up all of my PCB rules
and constraints for my specific project.
Again, for this project I'm keeping mostly the defaults,
but you can see there's a whole number of constraints
and rules that I can set up,
customize for my exact needs.
And most likely you'd define in this in a project template
or something like that, and run it through
the majority of your boards.
So we have electrical clearances, routing widths,
routing layers, component clearances,
almost anything you can think of that you may require
in a PCB designer rule check
we can define and customize here.
So I'm just going to do a very simple change here,
just for electrical clearances.
Currently the default was set to a minimum clearance
of 10 mil, but we saw that gave me some errors there.
So I'm gonna try to maybe make a change here
to let's say, eight mil.
And notice that it gets applied all the way through.
I can change each of these individually as well
if you want different clearances between
different components, traces and so on,
you can make all those individual changes as well.
I'm just gonna say across the board
I'm gonna change my minimum clearance to eight mil here.
I'm happy with that.
Again, a whole number of things we can make changes here to.
I'm just gonna make a very basic change,
and then hit apply.
And I can say okay there.
And right off the bat just visually pretty easy
to see there, if you noticed a bunch of these pads
were red indicating an error or potential DRC issue.
And now that's just gone away all of a sudden,
so most likely I've gotten rid of some of those
design rule check issues.
Again, I can run my rules and violations again here
just to make sure.
And now we can see we should have quite a few less issues.
And as you can see, I'm running through each of these
potential issues and there's my clearance constraint there.
Notice I had 18 violations previously.
It looks like all of those violations
have been resolved now.
So I'll still just manually maybe have to switch
or move some of my silk screen information there
to get rid of these five violations,
but you can see very easily, very very useful
just to see if there's any potential issues, errors
or warnings in your PCB design.
This auto PCB software will help you determine those,
show you where they are and then you can easily
and quickly make those changes to fix up
your board design.
And again I will run this again at say,
the end of my project just to make sure
and fix up any potential issues, errors or violations.