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PCB Layout

Size of Pins

I've been trying to decipher the many numbers on the top picture, and it just doesn't make sense to me.

Why would you need a hole of size 1.19 mm when the pins are only 0.45x0.58 mm? This leads me to believe that 1.19 mm is the size of the pad, but then how big should my hole be?

I made the pin holes 0.762 mm. That should work right? What about the mounts on either side? Because, if I'm following the logic I used to discern that the first number next to a hole is the size of the pad, then I'm still left without a size for the hole. Nowhere else on the datasheet do they say how large the mounting pins are.

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  • \$\begingroup\$ Here is a link to the datasheet just in case anyone wants to see the whole thing:mouser.com/ds/2/418/NG_CD_5748482_A1-640737.pdf \$\endgroup\$
    – Micky-D
    Commented Aug 22, 2017 at 19:30
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    \$\begingroup\$ Max diagonal on those pins is 0.790 so 0.762 is far too small. 0.14 holes will give you a minimum clearance of 0.175mm which sounds about right to me. \$\endgroup\$
    – Trevor_G
    Commented Aug 22, 2017 at 19:45

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The pin holes are recommended to be 1.19mm diameter (nominal). The holes for mounting are recommended to be 3.18mm diameter (nominal).

You can make the pads as big or small as you like provided they offer sufficent clearance to adjacent pads and do not violate the minimum annular ring specification of your target PCB manufacturer(s).

There is clearance between the holes and the pins, which allows the connector to be easily inserted despite some slight misalignment or slightly bent pins.

The rectangular pins have a maximum dimension of 0.734mm (nominal). 0.762 seems way too tight and you may have trouble inserting the pins. 1.19 is a bit sloppy though- I would think 1mm would be plenty. Also check alternative suppliers of the same part to see if other manufacturers may use a larger pin.

Edit: Just to give you an idea of the volume that has to be filled by solder using the recommended hole size, here is a model showing the nominal pin size (maximum is outlined, as is a 1mm hole diameter).

enter image description here

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    \$\begingroup\$ Isn't it 0.79mm assuming worst case 0.62mm and 0.49mm rectangle? \$\endgroup\$
    – Rev
    Commented Aug 22, 2017 at 19:45
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    \$\begingroup\$ 1.19 is also 3/64" a fairly standard imperial drill bit. Most of these parts started out in inches. \$\endgroup\$
    – Trevor_G
    Commented Aug 22, 2017 at 20:16
  • \$\begingroup\$ Thanks for the help everyone! I'll keep the holes at 1.19, because that seems easy to manufacture and I shouldn't run into any problems there. \$\endgroup\$
    – Micky-D
    Commented Aug 23, 2017 at 15:44
  • \$\begingroup\$ @Rev1.0 yes, that's the worst case with tolerances included (I noted the nominal maximum dimension). In fact the rectangular pins (unlike round ones) can usually be forced into a slightly smaller hole but they'll skive off a bit of the plating. There also is no room for misalignment of holes relative to the pins but usually they have a bit of compliance at the board plane. \$\endgroup\$
    – Spehro 'speff' Pefhany
    Commented Aug 23, 2017 at 16:31

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