JEDEC footprints general information

[mikey]

Hi, everyone!

I am new to this forum and to surface mount prototyping.

I know how to make footprints using PCB software and I am aware of the JEDEC standards.

My question is:


Is there a downloadable source or book that I can purchase where I can see what the nominal size footprints actually look like in terms of actual size (so I can get an idea of how small the part is that I am actually going to be working with) and which will also give me dimensions of the footprint (metric or English standard is okay)?

Thanks for this general information. I tend to think this information should be openly available to the public but it does not appear to be well publicized. Don't you think so?

[randychase]

There is a lot of stuff here-
http://www.pcbstandards.com/forums/showthread.php?t=2256

[mikey]

Thank you for the fast reply. It was appreciated.

I am not always on the net and I tend to think using the net can be a little inconvenient (although I am eternally grateful for the link), do you know of folder one can purchase where they show a simple footprint picture (actual size) and then following the footprint they show a graph of the dimensions of the footprint.

I think a manual like that would be a best seller. Don't you think so?

[Skip Yutkus]

The book exists as an IPC Document - used to be IPC-SM-782 but that has been superseeded by another, acoording to IPC doctrine at present only Metric is acceptable, since this will soon be the universal measurement system - (remember the speed limit signs with KPH - they kinda disappeared) - as for showing the actual size it's really of no value nowadays - an 0201 part can be placed on a period in the book.

Skip

[randychase]

Yeah. I have mixed feelings on the whole Metrification thing. I think it goes without saying that a single standard makes sense. But on the other hand, I am reading this on a 21 INCH monitor. I don't see people dumping the Number 4-8 screws in favor of M sizes.

I think we will be dealing with certain non-SI measurements for a while. How long? I do not think I will live long enough to see a "one world" standard.

Also, I don't buy in that it is that critical for PCB design, though I do like that one standard can help reduce errors induced by translations. My PADS system does not care if I design a metric part in and route it in inches. And I don't care if they use more decimal places.

As to actual size, I think there is a value, though not so much in the 0201. :) Using a manual that has all the sizes at 1:1, I can easily verify the correct land pattern (crude though this method might be) by placing a part on the printed pattern. I often do this on the pcb check plot also to verify things. Not a big deal, but it can help.

[Skip Yutkus]

Ha! I'm not the only one! I routinely print a 1 to 1 after building a new complicated footprint and drop the part on it, trouble is with some parts these days, even the larger ones a few thou. can be a disaster - as for metric, I learned many years ago to convert in my head, (roughly anyway), so I don't really care. But in general I don't think you'll see a mass exodus soon.

Skip

[actionplus]

Any idea where I find the ISO 7816 footprint?