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I am designing a footprint for the UJ2-AH-SMT female USB connector for use on a PCB. I have been following their datasheet for the recommended PCB layout drawing. There are two small holes underneath the pads, I assume to help line up the connector on the board. For the dimension of the holes, it says "2-⌀1.30". How big should I make my drill hole/pad size so that it is the best fit for the connector?

Picture of PCB layout:

Recommended PCB layout

-Ben

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That is a recommendation of layout, not the size of the pin itself. In this case, the hole should still be 1.3mm.

If you look at the mechanical drawing of the part, it shows that the pin is 1.18mm wide, so 1.30mm clearly accounts for some margin.

If you are really unsure, you can ask you assembly house if such tolerance is enough for the placing machine. If you are placing by hand, you should be fine.

enter image description here

A different question is how your fab house interprets those hole dimensions (some interpret as finished dimensions, other as drill size), but this is a problem for plated holes mostly - not the case here.

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  • \$\begingroup\$ This might be a dumb question, but what does the "2-" in front of the ⌀1.18 mean? The only thing I can think of is that it's because there are two pins on the connector. Is that correct? \$\endgroup\$ – AngryCupcake274 Apr 25 '17 at 23:08
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    \$\begingroup\$ Yeah, although the references I could find recommend the usage of the letter "X" instead of "–" for repeated dimensions. \$\endgroup\$ – Wesley Lee Apr 25 '17 at 23:29
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    \$\begingroup\$ I take the "2-" prefix to mean that the same dimension is used in two places. Fairly standard nomenclature. \$\endgroup\$ – Dwayne Reid Apr 26 '17 at 0:18

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