What is the best way to build/use Altium (or other software) parts that have multiple physical pieces. This could be multiple footprints that work as a set, it could be multiple MPNs that form an assembly of some sort etc.

Example 1:

In a new design I have to work with some Beckhoff PLC parts, for example this: https://www.beckhoff.com/EJ1819/

These are designed to be plugged onto a pin header on a PCB, with some coding holes around the header to prevent misconnection of different modules. The simple way to deal with this would seem to be to have two parts. The pin header would be the schematic part with connections to it, and would use a dedicated footprint for 'pin header + coding holes'. The PLC module itself could then be a separate schematic part, with no connections, and a footprint that was just a step file which could be aligned to create the final 3D view of the assembly.

The same concept doesn't work as well however for the https://www.beckhoff.com/EJ1918/, which uses two pin headers. I would like a single PCB footprint which would help keep things aligned, but on the BOM I will want 2x the header, with their own designation, so 2x SCH symbols.

Example 2:

IC sockets.

These aren't widely used nowadays, but if you wanted an eeprom/logic chip which was in a removable IC socket, the desire would be an EEPROM/multiple logic gate symbols on the schematic to make the design clearer. But the physical connectivity would be to a generic IC socket, and both parts would need BOM entries.

Example 3:

Displays with mating headers and possibly ribbon cables.

This is a use-case that I have solved before with the proposition in example 1. The PCB connector is the main part, and the display itself and any cables are added as schematic parts without connections/pins. They simply add BOM lines and put STEP files into the PCB.

  • \$\begingroup\$ The sense in putting something on the PCBA BoM that plugs into said PCB is lost on me. Ever heard of BoM structures? If you are trying to use a single BoM as a parts list then you are misusing what a BoM is for and that is the building of a part at one particular stage of production. Adding the IC by plugging it into the socket is the next stage and will / should appear hierarchically at a higher/different level. \$\endgroup\$ – Andy aka Jan 16 at 14:15
  • \$\begingroup\$ It depends on your workflow, and to an extend, is a case by case basis. We would, in the displays example, ask our CEM to build the board up to and including these displays. This allows them to fully functionally test them before shipping to us as a known working sub-assy which can be built into product. They therefore get one BOM with all the required parts including these displays. Our overall product BOM then calls a part which is this finished assembly. Much like any other sub-assys which may have separate BOMs to allow a separate or outsourced build. \$\endgroup\$ – Chuck990 Jan 16 at 14:24
  • \$\begingroup\$ I'd make one part that has a footprint that fits all the necessary locations. Then make mechanical parts for each of the other items that needs to be added to the BOM. It will be up to you to make sure all the necessary mechanical parts are included. You might be able to use "snippets" to pull all the parts into your schematic with one operation, but I've never used that feature. I'm pretty sure there's no way to break the "one item on the BOM for each item on the schematic" rule that isn't abusing the tool. \$\endgroup\$ – The Photon Jan 16 at 16:56

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