Footprint for 0.45uF tantalum capacitor


#1

I want to use a 0.45uF tantalum capacitor. I have (for the moment) taken a punt on
Capacitors_THT:C_Disc_D4.3mm_W1.9mm_P5.00mm
Is this okay?
Does it really matter as long as the pitch is 5mm and there is some space for the body?


#2

Yes, as long as the holes are spaced correctly, and there is room for the component you will be OK,

However you would want to add a polarity marker if the footprint doesn’t have one.


#3

Thanks/ I’ll do that.


#4

What I do when I am working with new components and footprints is to print out the PCB and then try placing the components on top of the pads or seeing if the legs poke through the holes of the pad easily. You can initially poke small holes in the paper with a needle and then the legs of the components will easily fit in and you can see if the pad diameters and spacings are correct.

Doing this allows you to quickly and easily see if you have the correct footprint for a particular component.


#5

OMG! I just believe in what I measure and if dimensions of footprint are the same.


#6

Reading between the lines (and based on my own experience), @kerrsmith has probably been bitten by an incorrect datasheet and/or human error transcribing from datasheet to footprint.

Thus the extra effort to do a quick sanity check to feel better about the design. (I was recently bitten by this because I didn’t realize the 8-pin sockets that I got had crimped pins. My THT holes were large enough for the pins after straightening, but it was annoying to have to do that extra step and defeat a feature that makes it easier to hold the part in the board when soldering… Unfortunately, my project schedule didn’t allow for me to get the parts before sending the board out for manufacture…)


#7

Reading between the lines (and based on my own experience), @kerrsmith has probably been bitten by an incorrect datasheet and/or human error transcribing from datasheet to footprint.

Yes, I quite often make my own PCBs by etching them so it is certainly worth the couple of minutes it takes to check the new components I am using to make sure they actually fit in the holes of the footprint I have chosen.

After spending the time etching a board it is quite annoying to find your chosen footprint for a component is not quite right. Even more irritating if I send off for the board to be made and then find a part does not fit.

I only do this check on new components, once you have used them once you know the correct footprint to use.


#8

Yeah, same here. On occasion I have made a mock-up like this and populated it with a few parts to check the mechanical fit in an enclosure - especially when I’m concerned about the (mechanical) interface between my PCB assembly and jacks, switches, controls, mounted on the enclosure; or concerned about clearance to the enclosure, or to another assembly mounted inside the enclosure.

Dale


#9

Some time ago I posted a little tutorial for printing the PCB layout on paper to test footprints before ordering the PCB.
https://forum.kicad.info/t/tutorial-test-fitting-footprints/6778


#10

That’s a good tip. Thanks