Designing a PCB can
be a complex process. If you don’t have everything in place from the get-go,
you could run into problems much further down the line. That’s why it’s
important you pay close attention to detail from the get go. Here we discuss
things to consider when designing your PCB.
The PCB Stack Up
The PCB stack up
will determine how many layers are within the PCB, and as the number of layers
increase - as does the cost. The stack up will allow the engineers to establish
the characteristics of each layer. There is of course a balance between getting
the yield and reliability as it should be as well as taking the costinto consideration.
Choosing the
Correct Via Type
There are many different via types. You can opt for a
single layer, a multi layer or a stacked via. The best designers will try to
ensure there aren’t lots of different types of via within the same PCB. It’s also critical that you make sure that
the current capacity of the via you have chosen is enough if you need it to
accommodate a high current path.
Follow the Design
Rules
When it comes to
the actual design work itself, you need to think about component placement,
where the layers will be allocated, the length and time of flight analysis and
more. This will also include the design
manufacture rules – where you need to think about whether or not your aspect
ratios are as they should be. There are
design tools such as Altium that can help you
on your way here.
Traditional, Layers
or Hybrid Style?
Before you start the process of verifying
power/signal integrity – you need to check high-pin count devices to ensure
that all of the signals can be routed.
You need to also bear in mind that this will have a direct affect on the
stack-up. If you choose a micro-via
breakout, which is the most likely option – think about how deep you are
stacking. After your stack has been
defined, you can then work on the routing.
You can opt for traditional (North, South, East and West), a breakout
that is layer based – or else you can go for a mixture of the 2.
Signal and Power Integrity
When designing a PCB – one of the things that you
definitely need to consider is the rise and fall times of the signal, as well
as the slew rates of the terminations and drivers. In order to maximise the performance – there
should be signal integrity simulations pre and post layout. For high performance devices – remember that
you may need large currents with low voltages.
Checking in on the performance of the DC and AC power distribution
network is critical.
As designing a PCB can be a complicated process,
you need to make sure you have things right every step of the way. Hopefully our handy tips will have you on the
right track and ensure you don’t run into any issues.
0 Comments