The PCB Looked Finished Until I Reviewed It: 12 Checks Before Ordering
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The problem: A routed board can look complete while containing a mirrored connector, missing return path, or untestable power rail.
The goal: Review electrical intent, physical reality, manufacturing, assembly, and test before ordering.
The result: Twelve checks that turn “DRC passes” into a reviewable release decision.
AI-generated illustration of a design review, not a manufactured board from this series.
The green board on the screen looked like a product
The traces were routed, the ground zone was filled, and the 3D view looked convincing. That visual finish created a dangerous feeling: the PCB seemed done.
Then a review question changed everything:
If the connector is mounted on the real board, which side is pin 1 on?
The layout was not a product yet. It was a set of assumptions waiting to meet copper, components, cables, tools, and a manufacturer.
DRC is necessary, not sufficient
KiCad's Design Rules Checker can verify clearances, connections, and consistency rules configured in the project. It cannot know that a button is unreachable behind an enclosure wall or that a connector is facing the wrong direction.
Review the board in five layers: intent, components, power and signals, mechanical construction, and test/manufacturing.
Twelve checks before ordering
1. Schematic-to-PCB consistency
Update the PCB from the final schematic, refill zones, and enable schematic/PCB parity checks. Confirm there are no unexpected unconnected items or stale footprints.
2. Exact footprints
Compare the footprint against the manufacturer package drawing: pitch, pad numbering, body size, exposed pad, courtyard, and orientation mark. Print the board at 1:1 scale and place real components on the paper where practical.
3. Connector orientation
Inspect the mating connector and cable, not only the PCB footprint. Check top-versus-bottom view, pin 1, keyed direction, cable exit, and whether reversed insertion is possible.
4. Power path
Trace current from input connector through protection and regulation to every load, then back through ground. Size copper, vias, connectors, and protection for expected and fault current—not only signal current.
5. Decoupling placement
Place each decoupling capacitor close to the relevant power and ground pins with a short current loop. A correct capacitor value far away is not the same electrical object at high frequency.
6. Return paths
Every changing signal has a return current. Avoid routing fast signals across gaps in their reference plane. Keep noisy motor or switching-current loops away from sensitive analog and communication paths.
7. Clearances and manufacturer limits
Configure track width, spacing, via size, drill, solder mask, copper-to-edge distance, and layer stack for the selected manufacturer. A generic default rule is not a fabrication agreement.
8. Thermal reality
Estimate loss in regulators, MOSFETs, diodes, resistors, connectors, and copper. Check thermal-pad geometry, copper area, vias, airflow, enclosure temperature, and neighbouring heat sources.
9. Mechanical fit
Verify board outline, mounting holes, keep-outs, component height, enclosure walls, buttons, LEDs, antennas, and tool access. Import or compare mechanical drawings when available.
10. Assembly
Check polarity marks, readable reference designators, hand-solder access, fiducials if required, component spacing, and whether parts are all on the intended side. Confirm the BOM and pick-and-place data use the same variants.
11. Bring-up and test access
Add clearly labeled test points for ground, input power, regulated rails, reset, programming, and critical buses. Make them accessible with the board installed when that is a requirement.
12. Independent review
Ask someone who did not route the board to review it against requirements, data sheets, reference designs, and the schematic. The designer's familiarity makes missing assumptions look normal.
Release evidence
Before generating manufacturing files, save:
- schematic and PCB source revision;
- clean ERC and DRC reports or justified waivers;
- BOM with manufacturer part numbers;
- fabrication drawings and layer stack;
- Gerber and drill viewer screenshots;
- pick-and-place and assembly drawings;
- 3D and 1:1 mechanical checks;
- design-review checklist and decisions;
- planned first-power-on procedure.
Open the exported manufacturing files in an independent viewer. The factory manufactures the outputs, not the intentions inside the CAD project.
Completion checklist
- [ ] Footprints match manufacturer drawings and real parts.
- [ ] Connector pin 1 and mating direction are confirmed.
- [ ] Power and return paths support worst-case current.
- [ ] Decoupling loops are short.
- [ ] Layout rules match the intended manufacturer.
- [ ] Mechanical fit and component heights were checked.
- [ ] Test points and programming access exist.
- [ ] ERC/DRC results and waivers are recorded.
- [ ] Exported manufacturing files were independently viewed.
- [ ] Another person reviewed the release package.
Next experiment
A reviewed board can still contain an assembly fault or an incorrect assumption. Next, I will prepare a controlled first-power-on sequence that stops at the first abnormal sign.
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