Recommended DIP footprint - Page 1
Forum section: electronics / beginners

author: Sparky49
author_rank: Regular Contributor
timestamp: December 03, 2021, 07:50:43 pm
content: Hi I would like to make a footprint for a DIP20 package, but I cannot find any information regarding the recommended distances between pads. I know the dimensions of the part (standard PDIP20), but I can't find a single source outlining suggested distances between the holes/pads on the PCB, hole size, pad size, etc. Does anyone have this info? Thanks in advance.

author: james_s
author_rank: Super Contributor
timestamp: December 03, 2021, 08:18:49 pm
content: Surely whatever EDA you're using already has a DIP-20 package? Otherwise look at some of the other DIP packages for ideas. It really isn't critical, generally you want the pads as large as practical, leaving enough space to run a trace between two adjacent pads. Many times elliptical pads are used to increase the spacing between them.

author: Sparky49
author_rank: Regular Contributor
timestamp: December 03, 2021, 08:48:16 pm
content: Thanks, I use Altium and it doesn't have any prebuilt packages (unless I've missed something obvious after all these years lol). If I could find guidance on a smaller or larger device I would just extrapolate the pad spacing, but I can't find that primary information.

author: jpanhalt
author_rank: Super Contributor
timestamp: December 03, 2021, 08:57:57 pm
content: https://app.ultralibrarian.com/search?queryText=20-pin+DIP

author: Sparky49
author_rank: Regular Contributor
timestamp: December 03, 2021, 09:02:28 pm
content: Thanks, I appreciate the links to existing models/footprints, but I would like to know the recommended dimensions/procedures etc so I can make my own. What references did the people who made those footprint files use?

author: james_s
author_rank: Super Contributor
timestamp: December 03, 2021, 09:03:57 pm
content: The datasheet probably, and a mix of experience and common sense. Making a DIP package is not unlike making any other package, it's not rocket science.

author: floobydust
author_rank: Super Contributor
timestamp: December 03, 2021, 09:12:00 pm
content: Narrow (shrink) DIP-20 no different than more popular shrink DIP-28. There's wide variations in footprints for through-hole parts.Some designers go with small pads so they can run one or twotraces between pins. Easier if pad shape is rectangular. Hole size is to accommodate any socket, machined pin sockets have bigger pins.

author: Doctorandus_P
author_rank: Super Contributor
timestamp: December 04, 2021, 01:13:09 pm
content: Any datasheet of an IC should have the dimensions of the package.Usually it is one of the last pages of the datasheet.

author: westfw
author_rank: Super Contributor
timestamp: December 07, 2021, 07:53:56 am
content: QuoteI'd normally start with the required hole size (usually 0.7 to 0.8mm. May depend on whether you plan to use a socket.) For some CAD packages, this will imply a pad size, but I'd normally let that expand a bit for easy hand-solderability and robustness. Or shrink it to the minimum supported by my PCB manufacturer if I want to run a trace or two between pads.I believe you are more likely to be limited by your manufacturing process than by IC specifications. (Though occasionally there might be special considerations - extra thick leads for heat dissipation or something. In those cases, I'd expect advice in the datasheet.)