I’m trying Eagle freeware for the first time on a really simple board - it is an adapter with one IC and two connectors.
The package is something new that I was unable to find in any existing library. Linear Tech calls it UTQFN, with 28 pads (29 including the ground on the bottom) in a 4mm square package.
I created the device (symbol and package) in a new library, and drew the schematic. The problem is when I have Eagle create the board, there are no connections to the UTQFN package. There is one ratsnest trace between the two connectors (ground), but otherwise there are no nets showing in the board view.
In ERC I get errors that the net overlaps the pin on my new symbol, and “only one pin” on the nets connected to the connectors. When I zoom in, they appear to be touching my new symbol’s pins with the same overlap as on the connectors (the overlap is about the width of the wire).
I notice that I can move the wires attached my symbol, and they move off the pins, but when I move the wires near the connector symbols, they are “stuck” to the connector pins. What defines the connection between wire and symbol’s pin? ( In the manual it mentions the Auto End Net and Auto Set Junction settings in Options/Settings/Misc. They are checked).
Did you connect your package pins to the symbol pins?
Library → Device ~ open your device name → select the connect button.
Did you change the grid when creating your symbol? If you play with the grid in the schematic you can get pins that look like they are connected to nets, but actually aren’t.
Otherwise, give us your library and we can take a look at it.
Mark, Thanks for the reply. Yes the package pins are fully connected in the connect dialog. The grid for the symbol is standard 0.1 inch. I changed the grid for the package to 0.2mm though. But there is no problem connecting the symbol to the package. The problem is connecting wires to the symbol in the schematic editor.
You have a top layer wire that connects all of your pins together as one in the package. I’m not certain what that square around your part is supposed to be. If it’s meant to be an outline for the package, change it to something like tPlace.
Good catch! I fixed the outline by moving it to the Tplace layer.
I finally deleted all the wires on my schematic and re-wired everything. Now there is connectivity. I suppose when there is a library error, the wires somehow “remember” that they can’t connect, and will not ever connect again.