Calculator tool: board classes

[Pere]

HI,
The calculator tool includes different minimal values for board classes. Anyone knows the reference or standard for these values? Thanks

[paulvdh]

Do you mean this table:

It’s probably based on some IPC standard, but they want three digit number monetary units for a piece of paper. A generic search finds lots of websites with partial information and a lot mention IPC.

https://html.duckduckgo.com/html?q=pcb+board+class

But beware. IPC also has a system in which they divide PCB’s into three classes (1, 2 & 3) and that is a completely different list.

[mf_ibfeew]

The table you have shown is based on IPC2221 (there was helpful string added in v7.99)

[Pere]

I have searched in the IPC-221 but i could not find this reference. Could you include a screenshot forr eference? Thanks

[mf_ibfeew]

No, I don’t own the IPC2221 (note: 3x “2”). But a google-search with the search phrase “IPC2221 isolation classes” returns many webpages. If you restrict search to “pictures” you get many tables similar to the table in the kicad calculator.

[paulvdh]

This search seems to work:

https://duckduckgo.com/?hps=1&q=ipc2221+isolation+class&iax=images&ia=images

But they give another table, it is more like the “Electrical Spacing” table in KiCad.

[mf_ibfeew]

@Pere and Paul: Forget all my answers, I was always referring to the false table with the isolation (clearance) values. For the table with class 1…6 I have no clue.

[BlackCoffee]

If I wanted to know about the IPC 2221, I would google ‘IPC 2221 Specification’

The first item that showed up is the Govertment’s spec - here it is and below is snippet…

[paulvdh]

That also does not help. All references to “Class” in IPC 2221 seem to be to the three “produciton classes” I mentioned earlier. You find a lot of references to those, and references to those 6 “design rules” classes are much harder to find.

[BlackCoffee]

You missed my point… Point being, is to be more specific about searching. Five seconds of typing into search-field can bring up what a user searches for… so, if wanting to search for a specific doc, do it (example Link above). If wanting to search for a family of doc’s do it… (example: search for ‘IPC Standards’…)

Here’s result showing a full Enchelada…

ADDED: A Classification Chart (that goes beyond Class3)…
ADDED: Reference to IPC 2222B - showing classes 1-thru-6