Are Net in Schematic the same as Net in PCB?

Schematic
1

Hi, my first question here.

As a newbie I don’t get the Net!

Is the Net in Schematic the same as Net in PCB?

If not can I use it to double check my work?

Can I put them together???

/Dan Olsson

2

There is a bit of a difference between a net (A collection of connections, for example pin 1of a resistor connected to the base of a BJT) and a netlist (A list of all the nets, the complete connectivity of a schematic). And yes, it is an essential part of KiCad (or any other PCB design program) to transfer the netlist to the PCB editor and verify connections. This is done with DRC. This is all very basic lesson 1 of an introduction tutorial. Find and read some of those. (Together with KiCad’s own Getting started and user manuals).

3

Well, they are supposed to be.

You start with a schematic. You assign net names, or let the schematic software auto-generate net names. Then, those nets are used to route the PCB, which lets you confirm that the pcb routing matches the schematic.

4

In past to get netlist from schematic you had to export it from schematic to file and then import it into PCB. Since KiCad V5 being in PCB you have “Update PCB from schematic… (F8)”. I use this function icon from top toolbar. It is KiCad task to make netlist at PCB being the same as in schematic (being a part of the same project). If it can’t do it you will see Errors list.

5

Double check:

  1. if schematic is correct (KiCad can’t know your idea) and
  2. if footprint pads are correctly assigned to schematic symbol pins.

If these 2 are correct than DRC in PCB will check the rest.

To avoid possibility of error from point 2 I use only my symbols already connected (and double checked) with my footprints.

6

For “double checking” your work, the workflow is as follows:

  1. Check / verify your schematic. The schematic is the origin of the nets and the netlist.
  2. Schematic Editor / Tools / Update PCB from Schematic [F8] ports the whole netlist (and the footprints) to the PCB editor. There can be a lot of errors and warnings during this process. Some are a bit “meh”, others are important.So do not just dismiss or ignore them.
  3. This process also flags pins in the schematic / netlist, but with no pad on the PCB footprint. That is one of the things you have to watch out for.
  4. If the “Update PCB” works without errors, and DRC also does not flag missing or faulty connections, then connectivity is on the road to a good end, but there are many other considerations for designing a “good” pcb too.

I run the Schematic Editor / Tools / Update PCB from Schematic [F8] often and repeatedly during design of a pcb. As a result, I build up the PCB in manageable sections, instead of first making a complex schematic, and then putting hundreds of footprints on the PCB.

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