How to read datasheet for making custom eagle packages...

[corrado33]

Hey guys, I can't seem to read this measurement in this datasheet for a product I saw on digikey.

Here's the pic..



I get most of the measurements, but what's up with the measurements for the hole?  One says 3-Ø1.1.  What's the Ø mean?  Could someone enlighten me?

I THINK it means that there are 3 holes with a radius (or diameter) of 1.1 mm.  Am I right?  Also, are these numbers how big to make the holes in the PCB, or is it how big to make the pads?  Cause if it's for the holes, there's not much room to add the pads. 


Oh and I just noticed, I'm a ROBOT OVERLORD!!! MUHAHAHAHAHA.

[SmAsH]

Yes, i assume that the holes marked #1, #2 and #3 are all 1.1mm.

[Razor Concepts]

Those are holes, 1.1mm in diameter

There isn't much room for pads, but there should be enough for some small ones.

[Soeren]

Hi,

There's a shade less than 1/10" pitch in pins 1..3, so that shouldn't be a problem.

When making the holes, if you plan to use them for making your own boards, make the holes around 0.3 to 0.5 as you only want to control the drill. If you make a hole of 1.1mm and use a 1.1mm drill, there's a great chance of the hole being slightly offset and some of the copper will end up being a bit of distance from the pin, which will likely give problems with the soldered connection over time and make it harder to solder in the first place.

[corrado33]

Hi,

There's a shade less than 1/10" pitch in pins 1..3, so that shouldn't be a problem.

When making the holes, if you plan to use them for making your own boards, make the holes around 0.3 to 0.5 as you only want to control the drill. If you make a hole of 1.1mm and use a 1.1mm drill, there's a great chance of the hole being slightly offset and some of the copper will end up being a bit of distance from the pin, which will likely give problems with the soldered connection over time and make it harder to solder in the first place.

Good tip!  Thanks!

[vinito]

Hey guys, I can't seem to read this measurement in this datasheet for a product I saw on digikey.

Here's the pic..
I get most of the measurements, but what's up with the measurements for the hole?  One says 3-Ø1.1.  What's the Ø mean?  Could someone enlighten me?
I THINK it means that there are 3 holes with a radius (or diameter) of 1.1 mm.  Am I right?

Hey, here's a question I can answer, though it's pretty much been taken care of already (I'm a machinist, not much of an electron guy yet)
Yes you're right. (short answer)
It is standard machining notation. Ø does mean diameter. Radius notation would just be an R. So it's 3 holes @ 1.1mm diameter, then the tolerance is +.1/-0, which means it can be as large as 1.2mm but no smaller than 1.1mm. Since it says "piercing plan", that has got to be referring to the hole size and not the pad. In my world, the part would be scrap if the hole was anything outside the specified tolerance. But if you're making your own specifications, then freedom to take liberties is yours.
It wouldn't hurt to start with a smaller hole since you can always make it larger afterward (on a roll-your-own board), though going from 1.1 down to .3 to .5 seems pretty extreme, but I'm used to dealing with mechanical fits in which .6mm would be a huge deal. For a through hole, there always seems to be plenty of wiggly clearance on boards I've dealt with and you should be able to get by with a smaller hole. But too tight would be a PITA too, so if it were me, I'd measure the actual pin if you need to really know what you're dealing with. Easy for me to say since I've got a crapload of different instruments surrounding me to do that with. But a cheap dial caliper should be plenty good.

When it comes down to the actual nitty gritty of making PCBs, I'll defer actual decisions to those with the specific experience.