Unable to connect two ends of the same signal

Layout
1

Hi,

I’ve a signal connecting two components, a central pad of a small QFN IC, and a resistor.
I’m not able to connect these two ends of the signal. When I tie the trace towards the resistor pad, it’s not possible to connect it.
When I start from the resistor pad, I’m able to start the trace, bit I cannot connect it to the trace coming from the IC.
What could be the problem?

image
image832×338 98.4 KB

Thanks,
Leo

2

Hi,

I’m trying to connect signals to a small IC.
I don’t succeed to connect traces to any pad.
I reduced minimum clearance to 0mm in Board Setup.
I also tried reducing the trace width, with no succeed.

image

What could be the problem?
Thanks,
Leo

3

Where did you get that QFN footprint from? It looks like there’s a border that’s not allowing tracks to reach the pads.

4

Hi,

The IC is from Texas Instruments, and from their site I was redirected to Ultra Librarian.

In which part of the footprint pad’s do you suggest checking for such border?

Thanks,
Leo

5

Does the footprint have a shape on the edge cuts layer? If so, that is the problem, that shape should instead be on a fab layer.

Always be suspicious and double-check content from services like Ultra Librarian.

You can route the trace in “ignore collisions” mode and then run DRC if you want to have KiCad tell you exactly what the problem is.

1 Like
6

This looks like pad clearance to me, but I admit, it’s narrow.

The center pad has a SMT pad with pad number 3 and a THT pad with pad number 6. That does not work well in KiCad. Give these pads both the same pad number, 3 is probably the logical choice, but I have not seen the datasheet.

7

The rats nest lines make little sense unless there are some track fragments belonging to other nets