diff --git a/modules/library-conventions/pages/packages.adoc b/modules/library-conventions/pages/packages.adoc index f9a28362..96cd54eb 100644 --- a/modules/library-conventions/pages/packages.adoc +++ b/modules/library-conventions/pages/packages.adoc @@ -84,10 +84,20 @@ The following conventions apply to package names: == Pads -* *Always add all pads of packages*, even those which are not always connected. - For example, the package "TO220" has a metal tab, so you should define it as - a pad, no matter if it's often not connected (and even not connectable when - mounted vertically). +* *Always add all (electrical) pads of packages*, even those which are not + always connected. For example the package "TO220" has a metal tab, so you + should define it as a pad, even though it's often not connected (and even + not connectable when mounted vertically). +** If there are multiple pads which have a package-internal connection + (e.g. shielding pads of an USB connector), add them as one single package + pad and connect all corresponding footprint pads to it to make LibrePCB + aware of this internal connection. +** If there are pads for pure mechanical purpose without any internal + connection at all (e.g. split solder tabs of a plastic connector), don't + add any package pads for them -- just add footprint pads and leave them + unconnected. If in doubt, or if connected to a metal cover of significant + size, consider those pads as electrically relevant and tread them like + normal pads to allow connecting them in devices and schematics when desired. * *Use pad names according {ipc7351-pdf}[IPC-7351]* (if applicable). For packages which are not covered by IPC-7351: ** If the function of a pad is absolutely clear, choose its abbreviated