How to work with an electronics project

  1. Plan the connection in a system diagram
    • What is the form factor of the input and output connectors
    • How the connectors are assigned to the front and rear panels
    • Assign reasonable panel labels
  2. Panel design
    • Copy the past design files, as they are nicely designed for the LIGO chassis
    • If the PCB is directly mounted on the panel, be aware that the connector height needs to be precisely adjusted.
    • Arrange the connectors and the labels as planned in 1.
    • Is the planned connector assignment physically feasible?
    • If not, how should the assignment/arrangement be?
    • Once the design is done, reflect the modification in 1.
    • Save the panel files. Export the design in PDF and STP
  3. SCH/PCB design in Altium
    • Copy the past files depending on the # of layers (usually 2 or 4 layers)
    • First of all, copy the files and open them in Altium, then rename the file names.
    • Approximately design the circuit.
    • Look at the PCB file and remove all the components from the PCB (except for the PCB outline)

    • Use "Design/Import Changes From ....PrjPcb" to force the consistency between the SCH and PCB. Always incorporate the change into the PCB.

    • You'll face a bunch of errors because there are missing footprints. Update the library.
    • By the way the paper size can be changed from the "properties" panel of the schematic by selecting the templates.
    • How to make a library for the missing parts
      • Go to the "Manufacturer Part Seach" panel.
      • There, search for your favorite component. The component has to have a green IC chip mark (i.e., has a 2D/3D footprint model)

      • Click the component photo to download the model. It is downloaded to somewhere weird like c:\Users\Public\Documents\Altium\AD21\Library\ExportIntLib\

      • Extract the zipped library. Open xxxxxx.LibPkg. It contains PcbLib and SchLib.

      • Go to the downloaded SchLib and copy the component to your SchLib. The component has a strange name, so this is the chance to change the name for your convenience.

      • Go to the downloaded PcbLib and copy the component footprint to your PcbLib. The component has a strange name, so this is the chance to change the name for your convenience.

      • If you change the footprint name, the link between the component and the footprint is broken. Correct it by adding the footprint in the SchLib.

      • Try to incorporate all the 3D models into the parts as much as possible. It will help to match with the panels in the assembly confirmation below.
    • For the standard 19inch LIGO units, the board width is expected to be 14000mil. Use the dimensions to align the connectors along with the panel design.
  4. Assembly
    • aaa