footprint dimentions of 22uF tantalum capacitors

ronsimpson

Joined Oct 7, 2019
4,664
Most companies have the footprints on their web page. Mouser "ECAD Model:"
At digikey.com digikey
The links to "footprint" from anywhere you get parts will save you time!
 

Thread Starter

yef smith

Joined Aug 2, 2020
1,454
Hello ,In the mouser website they say case code 7361 V-case.
From there i saw its W=6mm but as you can see in the photo when i measured the pad myself i got 2.96mm.
So there is a contradiction.
Thanks.

1730382474417.png
1730382490963.png
1730382503979.png
 

Thread Starter

yef smith

Joined Aug 2, 2020
1,454

panic mode

Joined Oct 10, 2011
4,945
i do not see what the problem is....

the part number is TAJC226K025RNJ where highlighted "C" indicates package size.

1733233867196.png

the size 2312 is dimensions in imperial units.
23 = 0.230 inches
12 = 0.120 inches.

one inch is 25.4mm so you can convert that to metric dimensions if you like
0.230 inch * 25.4 mm/inch = 5.842mm
0.120 inch * 25.4 mm/inch = 3.048mm

and of course there is some wiggle room since all parts have tolerances.

the next part is to use this in EDA. you did not state what EDA you use but package like this are likely already in the library. you can also download it from online distributors. or you can make it. i have created hundreds of footprints and it is part of life when designing PCBs.

and if that is too complicated, don't use that capacitor. there are other form factors. or replace it with two 10uF...

and finally one can google the footprint dimensions. this is not exactly rocket science. astronomical precision is not needed... give it 0.5mm room all around the pads and a bit more (1mm) on the solder side and you'll be fine. I would probably go for something like this:

1733234880380.png


the pad size would therefore be
X=(8mm-2.9mm)/2=2.55mm
Y=3.2mm

so if center of the part is on the origin (0,0) then
center of each pad is at:
X=+/-(2.9+2.55)/2=+/-2.725mm
Y=0mm

then just add silkscreen mark for polarity and body width:
1733235608038.png


so.... what exactly is the issue...?
 
Last edited:

panic mode

Joined Oct 10, 2011
4,945
yup... in an eternal hassle, key details are ignored like not differentiating between W and W1.
part number in post #8 also changed. voltage rating dropped from 50V to 25V, the package size dropped from V to C...
oh well... it will all lead to some experience...
 
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