JMCPU - PCB validation process

PCB design validation steps details

File name

The PCB must be in the default directory as produced by EasyEDA. The file name must start with the PCB identifier followed by an underscore and end with the version number (e.g. PCB002_JMCPU Instruction Decoder v1.0).

Units set to mil

The whole project uses mil as length units.

Design rules check

DRC must return zero defect.

Components and nets must return correct values.

Example of a successful DRC

Schematic synced

The Update PCB button in the schematic must update this schematic and display no pending change.

Before clicking Update PCB, the whole schematic validation checklist must have been applied, including components updated from library.

All components updated

Design/Update Components from Library must return an empty list. If it doesn't, the schematic checklist must be redone.

Routing design recommendations

The following design guidelines should be applied when routing:

Board layout

Backplane connectors must be at the bottom, horizontal.

Holes must be placed on the standard grid. As many holes as possible should be placed. The board can be made slightly bigger to add one more hole row if necessary. Holes must be placed on the bottom layer to see them better.

The bottom row of holes around backplane connectors is mandatory, even if the connector is omitted.

DIL chips should be placed vertically, unless the board is made significantly smaller by placing them horizontally. Chips should be placed with the notch at the top or on the left.

Chips must be all in the same direction to avoid confusion and ease reading. SMD resistors can be reversed during soldering.

Pads must be aligned on the grid. Check for small misalignments that tend to appear in EasyEDA.

Board size

The board outline must be 137.5 mil outside of the screw hole center.

Correct board outline

Text size and orientation

Text should use one of the following font sizes:

All parts of the same type should have the same font size.

Prefer horizontal text. Labels should be on top of DIP chips (notch side).

Routing optimization pass

Avoid premature optimization !

Once routing is finished, remove useless complexity in routing. Make traces as short as possible. Remove useless vias.

Non-straight route

PCB fabrication validation steps details

Gerber generated

Check when the final gerber was successfully generated and sent for fabrication.

PCB built

Check when the PCB was received and free of defects. If the PCB matches the gerber but isn't as expected, this must be checked and all issues must be documented into the Known section.

Components fit

Check if all components fit their designated spaces.

Components soldered

Check when all components have been soldered.

Connectors fit

Check if all connectors connect correctly to their destinations.

First power on

Check if, after powering on, there was no short circuit, the magic smoke wasn't released, no component overheated and the current consumption was within expected limits.

Functional tests

Check if the whole thing works when assembled or if all functional tests were passed. Listing such tests in the page is heavily encouraged.

PCB documentation validation steps details

Link to Gerber

A link to the Gerber zip package should be provided in the page, under the matching version. The file name should be of the form Gerber_PCBxxx_JMCPU project name

Link to EasyEDA export package

A link to download the EasyEDA project should be provided in the PCB page, under the matching version. The file name should be of the form Project_JMCPU project name


A few pictures of the finalized PCB should be posted in the PCB page. Before the project is complete, a screenshot of the 2D rendering of EasyEDA is useful.

Assembly guide integration

The assembly guide should be upgraded to reflect changes introduced by a new version, or updated visuals if any.