I Am designing a 555 timer, that is discrete, with smd components, and in the picture, you can see that the components on the back have their traces inverted… I pressed F to flip them over, is it supposed to do this?
Update: I was using the wrong \footprint. Thanks for all the help 
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Can you be specific about what you think is not correct? What did you expect? What actually happened?
Also always mention the version of KiCad from Help > About KiCad > Copy Version Info.
Kicad takes care of the footprint transposition when flipping / changing side.
your red scribble looks correct. your traces look correct.
Did the board pass DRC ?
The transistor symbol has wrong pin numbers, it’s E B C, but for SMD version of 2N3904 should be B E C. (Datasheet)
Make sure you choose the correct transistor symbol for the footprint you are using.
Alternatively you can use my library, which (almost) always has correct pin numbers for any given specific symbol. And it has SMD versions of these transistors as well (just make sure you search for something like MMBT3904 instead of 2N3904)
Download it via the package manager and follow installation instructions here:
the way he has drawn the red scribble is correct, the pinout is BEC, and that’s what a MMBT3904 is. and the board layout appears to reasonably match the pinout.
It all comes down to what footprint you have chose to use with the 2N3904. The default footprint is for a TH component.
Kicad has a SMD Version (MMBT3904) which has the correct footprint.
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I’m talking about the schematic here:
Does not correspond to the SOT-23 footprint here:
I believe the OP said something about having to flip the transistor for the layout to be correct. Here the symbol is for the THT version of 2N3906 (2N3904 has identical issue), which has the pin order shown on the schematic, while the SMD version has E and B swapped.
A 2N3904 is a NPN transistor. You have a PNP symbol there.
It also suffers from the same issue, with schematic symbol for the THT version and an SMD footprint, here’s a datasheet for the THT version:
And an SMD version:
Sorry, I’ll correct the original post.
well, anyway the board is OK.
Are you sure?
I see Q19 base is connected to center pad of something (connector?). I don’t see Q17 and don’t expect this ‘connector’ is Q17. I don’t see that connector at schematic.
I used the wrong footprint
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Yes, I did run the drc
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