Best way to specify through-hole component mounting height

Manufacturing
1

What is the best practice to specify a height at which a through-hole component should be mounted during manufacturing so that this information is stored as part of the KiCAD project and then is propagated into fabrication files that will be understood by the manufacturer? For some applications this height is critical because the mounted THT component must make a physical connection with something else (e.g. indication LEDs that must interface with an indication window or light tube).

2

You could create a custom data field in the part data, using the “E” key. Store the heights in there, and they will always be in the Schematic.

3

Not good design practice IMO.
If you have parts that need to have a certain height that is not supported by the component itself, the right solution is to specify a “spacer part” or standoff or something else that wil ensure correct height.
Asking a manufacturer to keep something “floating” while soldering won’t work.

1 Like
4

So there is no standard way that would not use a custom field and would be universally understood by PCB manufacturers? It seems to me it would be logical to have it as part of, let’s say .pos file as an additional column there, don’t you think?

5

Thank you, I fully agree about this design practice not being great, and I would avoid it by using a spacer as you are suggesting, however, an underlying spacer will not allow one to subsequently bend the THT component leads after mounting so that it is facing the side, not the top as such spacer will envelop the leads… But I am open for other good design practice suggestions.

6

I generally agree with this, but I have worked with an assembly house to build a board with a custom LCD that needs to be at a specific height. They use a spacer during soldering, and then remove and re-use it for the next batch.

1 Like
7

Thank you so much for this advice!

8

The mfg could pre “crimp” the leads so the lead itself becomes the spacer. So I guess it depends on the part and the goal.

Is the goal a “Max” height?

9

So, the conclusion is there are no standard ways and not even recommended best practices to do this. It’s communication between you and the assembler. It’s not KiCad specific. Therefore I’ll close this.

10