Earlier today, I finally started understanding how to read a simple circuit schematic.
And naturally, that created another question. 😭
If a schematic is basically a map showing how components are electrically connected...
how does that drawing actually become a PCB?
Because there’s a pretty big difference between this:
battery → resistor → LED → ground
and an actual little green board with copper traces, pads, holes, and components soldered onto it.
So I wanted to understand the steps in between.
Turns out, there’s a whole process.
And weirdly enough, it’s starting to connect everything I’ve learned so far.
Step 1: Start With the Schematic
The schematic comes first.
This is where we describe the electrical relationships between components.
So I might have:
- a power source
- a resistor
- an LED
- ground
And the schematic tells me what connects to what.
The important thing is that the schematic doesn’t really care where those components physically sit on the final board.
It’s more like:
“These things need to be electrically connected.”
Not:
“Put this resistor exactly 8 mm away from the LED.”
That physical part comes later.
Step 2: Components Need Footprints
This was a new word for me.
A footprint is basically the physical shape a component needs on the PCB.
For example, a resistor might need two pads.
A chip might need 8, 16, 32, or way more pads depending on the package.
The schematic symbol tells me:
what the component does in the circuit.
The footprint tells the PCB software:
what the real component looks like physically and where it gets soldered.
That distinction made a lot of things click.
So now I’m thinking of it like:
schematic symbol → electrical idea
footprint → physical component
Step 3: Place the Components
Once every component has a footprint, the next job is deciding where everything should actually go on the board.
This is called component placement.
And apparently placement matters a lot more than I expected.
At first I thought you could just throw the components wherever they fit and connect everything afterward. 😂
But where components are placed can affect things like:
- how easy the traces are to route
- how big the PCB needs to be
- noise and signal quality
- heat
- whether connectors are actually accessible
Even on a simple board, it makes sense.
If an LED is supposed to be visible, maybe putting it underneath another component is not the greatest design decision. 😭
So PCB design is already starting to feel like a combination of electronics and puzzle solving.
Step 4: Connect Everything With Traces
And now something from my previous post comes back.
Traces.
Once the components are placed, the electrical connections from the schematic need to become actual copper paths on the PCB.
So a connection that looks like a simple line on a schematic might become a copper trace running across the board.
Basically:
schematic wire → PCB trace
This was a really satisfying connection for me.
Because yesterday I learned what traces were.
Earlier today I learned what schematic lines meant.
And now I understand how those two ideas are related.
The schematic says:
these components must connect.
The PCB layout decides:
here’s how that connection physically travels across the board.
Step 5: Sometimes the Trace Needs Another Layer
And this is where vias suddenly make even more sense.
Imagine two traces need to travel across the board, but there isn’t enough room for both of them on the same layer.
One trace might use a via to move to another copper layer.
Then it can continue underneath and possibly come back up somewhere else.
So the idea becomes:
trace → via → another PCB layer → trace
I already knew vias connected layers.
But understanding why a PCB designer might need them makes them feel much less mysterious.
They’re basically little escape tunnels for electrical connections. 😂
Then the PCB Starts Looking Like a Real Board
At this point, the project has gone from:
circuit idea
to:
schematic
to:
footprints
to:
component placement
to:
copper traces and vias
And now we actually have something that looks like a PCB layout.
That’s kind of wild.
A circuit that started as a bunch of abstract symbols slowly turns into something that could eventually be manufactured and held in your hand.
But You Can't Just Send It to a Factory Yet
Apparently there are still checks to do.
PCB design software can run something called a Design Rule Check, or DRC.
Basically, it checks whether the board breaks certain manufacturing or electrical rules.
Things like:
- traces being too close together
- pads overlapping
- traces being too thin
- connections accidentally being left unfinished
Which makes sense.
I'd rather have the software tell me:
“Hey, this trace is wrong.”
before I order 20 copies of the wrong PCB. 😭
Then Come the Manufacturing Files
Once the design is ready, PCB manufacturers need files that describe how to actually make the board.
One format I keep seeing mentioned is Gerber files.
From what I understand so far, these files contain information for the different parts of the PCB manufacturing process.
Copper layers.
Solder mask.
Silkscreen.
Drill locations.
And other board details.
So the overall journey looks something like this:
circuit idea
↓
schematic
↓
assign footprints
↓
place components
↓
route traces
↓
add vias if needed
↓
run design checks
↓
generate manufacturing files
↓
actual PCB 🎉
Seeing the whole process like that makes PCB design feel much less mysterious.
Everything Is Starting to Connect
A few days ago, I was looking at PCBs and basically seeing:
green rectangle + mysterious metal stuff
Then I learned about:
traces, pads, and vias.
Then schematics started making a little more sense.
And now I’m starting to understand how the schematic eventually becomes the physical PCB.
I'm definitely still nowhere near designing anything complicated.
But I finally have a mental map of the process.
And that feels like a pretty big step. 💚
But while I was learning all of this, I ran into something that immediately distracted me.
Apparently...
AI tools are starting to help with PCB design. 🤖
Schematic generation.
Component selection.
Layout assistance.
Routing.
Design reviews.
Maybe even generating parts of a board from plain English.
So tomorrow I’m going down that rabbit hole.
Because now I really want to know:
How much of PCB design can AI actually do?
And maybe more importantly...
If I'm still learning the fundamentals, should I even let AI help me yet? 😭
I guess we're finding out.
If you design PCBs, which part of the process took you the longest to understand?
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