Ronja Twibright Labs

Ronja Guidelines

Creating a PCB

  1. All components are in the upper left corner
  2. Pull them around so that pads and pins don't short circuit one into another.
  3. Set up all drillholes and copper annuli sizes of all component types according to table below
  4. Fix the netlist by editing the schematic in gschem and regenerating netlist from schematic until PCB stops beeping during "ew".
  5. Place connectors and lock them.
  6. Place components that constitute a borderline (shielding, optocouplers, transformers) into approximate supposed place of the borderline, lock them
  7. Send SMD components to the other (solder) side.
  8. Drag components onto right sides from borderlines where they belong
  9. Create ground planes and lock them
  10. Pins that are on ground:
    • Green them using "f"
    • Select -> Select all connected objects
    • SetFlag(SelectedPins, thermal)
    • Manually add thermal to locked pins (green)
  11. Green the ground and place components so that ratnests become as short as possible (working in the solder view) according to schematic. Prevent high concentration of ratnests in one spot - in such case, move affected components a little apart, to accomodate for future numerous traces, so that critical traces are as short as possible.
  12. Green the ground and SMD parts that are superfluous on the solder side flip back to the component side and vice versa and tune the ratnest to shortest length and reasonably low maximum local concentration of traces.
  13. Fix polygons - 40 mils from border. Draw a drawing with coordinates for this task.
  14. Correct silkscreen to be placed correctly and not cut out
  15. Connect grounded SMD pads to ground
  16. Route power polygons and traces
  17. Route traces from shortest to longest, prefer the solder side.
  18. Check that all filtering capacitor traces between capacitor and adjacent IC are short and thick and if not, fix them.
  19. Print out all postscripts zoomed
  20. Find all places where ground plane is broken and fix them.
  21. Shine the groundplane with 'f' and fill all places that are lighted as connected by a thermal and aren't
  22. Shine IC power line with 'f' and find IC's that have power omitted. Fix in schematic, regenerate PCB and fix.
  23. Find all places where ground plane is insufficiently interconnected from HF point of view and try to fix them
  24. Fix silkscreen
  25. Look out for dangling traces and traces that can be evened out.
  26. Check all packages if their numbering is correct by displaying the numbering using 'd'
  27. Check that packages have pin 1 square. Omit only those where the pinout isn't important.
  28. Check that all necks between adjacent pins of packages aren't thinner than minimum width copper and possibly fix them. inside them
  29. Run mask.pl
  30. Run pcc.pl
  31. Find all places where tiny garbage from ground planes is left, highlight them with a pen and then fix in the program.
  32. Fix silkscreen
  33. View with gerbv

Populating a PCB

Table of pin dimensions
Part typeMaximum lead diameterHole sizeCopper widthSources
0.25W resistor0.6mm0.7mm60 milMeasurement of blue capacitors from gme.cz and green TESLA: maximum was 0.55mm (green TESLA)
Capacitor0.7mm0.8mm64 milMeasurement of yellow ones from gme.cz - more types (shapes).
DIL?28 mil60 milCopied from I2C2P
CANON connector?0.8mm62 milCopied from I2C2P
RADIAL_CAN_200?0.7mm65 milCopied from I2C2P
RADIAL_CAN_300?0.7mm65 milCopied from I2C2P, only 60mil changed to 65mil (for it not to be less than RADIAL_CAN_300)
RADIAL_CAN_400?0.8mm75 milCopied from I2C2P
Elyte 13x210.6 nominal0.75mm70 milgme.cz catalogue
TO92?30 mil60 milCopied from I2C2P
Jumper pin?40 mil80 milCopied from Twister
1N5408?60 mil120 milCopied from Twister
Handmade coil?60 mil130 milCopied from Twister
SOD2726 mil30 mil60 milDatasheet 1N4148
TO-2201.08mm1.1mm85milLM7805 datasheet
An expected information missing here?