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When designing PCB's, I find myself very often having to make footprints for a significant portion of the components on my board. This tends to be very time-consuming, as (in Altium at least), dimensioning out land patterns for strange connectors or chips (those that can't be created from a wizard) isn't very easy. It seems like anyone that uses these chips or connectors would need a footprint, so I can't understand why these aren't more commonly provided. For example, right now I'm trying to put a USB 3.0 Micro-B connector on a board, but the top 5 connectors on Digikey don't seem to provide footprints. I have access to the Altium Live design content, but even that seems often pretty out-of-date.

I feel like there's something obvious that I'm missing - or else this system seems very inefficient (which usually isn't the case). Can someone enlighten me?

zplizzi
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    Because it is so easy to draw them yourself from the values in the datasheets? – PlasmaHH Jun 30 '15 at 13:51
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    Maybe my skills are lacking, but without Solidworks-style dimensioning tools (or anything better than just a grid), drawing out a footprint for a part like [this](http://media.digikey.com/PDF/Data%20Sheets/Hirose%20PDFs/ZX360D-B-10P%20drawing%20.pdf) would take me at least 15 minutes -which seems not-trivially time expensive and pointless for everyone who uses the part to have to do over and over. – zplizzi Jun 30 '15 at 13:56
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    Experienced PCB designers create their own footprints. Supplied libraries often have errors. – Leon Heller Jun 30 '15 at 13:57
  • There is no common way of providing soft footprints and providing footprints for all available design tools for all versions is uncommon – User323693 Jun 30 '15 at 13:58
  • @zplizzi: then you might need more experience. I don't do it often, but my wife can draw that one likely faster than I go search one, find it, download it, install it into my library, double check that it doesnt have any errors. – PlasmaHH Jun 30 '15 at 13:59
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    @Umar TI, for example, provides footprints in the Ultra Librarian format, which has a free version that allows conversions to most design packages. And I guess I do need more practice, but it still seems like you're more liable to make a mistake doing it quickly than using something the manufacturer designed and double and triple-checked. – zplizzi Jun 30 '15 at 14:02
  • FWIW I agree; most of the time the part designer has *already drawn the footprint* and included a picture of it in the datasheet. The data in datasheets should be more machine-readable. But that requires a standardisation effort that nobody has bothered with. – pjc50 Jun 30 '15 at 14:04
  • For your connector, you just need to practise. If you're designing in Altium a presumption is made that you have several years of design experience in that respect, or are willing to put that in. Eagle et al offer buggy community libraries, but... For simple parts that happen much, much more often they have the IPC compliant wizard that you can click through in less than a minute if you've done it a few dozen of times. Other than that, _some_ manufacturers supply Eagle and Altium libraries that are complete and accurate, such as Würth for connectors. (Says the Würth fanboy) – Asmyldof Jun 30 '15 at 14:04
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    I dearly wish PCB CAD tools incorporated proper dimensioning tools in their footprint editors. – Nick Johnson Jun 30 '15 at 14:06
  • There is also the question of how you prefer your silkscreen/documentation layers. Footprint editors all leave something to be desired and I do wish that vendors provided more standardized information, but I've done projects with vault-only parts and honestly I prefer the hands on, manual approach. Tweaking annular rings, thermal sizes, copper clearance, etc. is important for certain projects and when you get used to it, you're making them quick enough. – scld Jun 30 '15 at 14:07
  • That is not to say that I don't agree with the general point of this stuff having to be easier. If every design tool allowed import of a 2D industry layered standard, the designer making the datasheet could make that available and we'd all be done in 3 seconds. (remember: Not all, or even very few, datasheet drawers are EE-engineers, they just clean up specs into an AutoCad or similar drawing) But, as it is, I have developed a knack of reading those images and 10's of years on can design most footprints in a minimum of time in the software I have worked with, at least in the last 10 years. – Asmyldof Jun 30 '15 at 14:08
  • @NickJohnson I don't mind the PADS footprint editor. If you just keep changing the origin around to each terminal, it plays a bit like autocad. That being said, they still all suck. – scld Jun 30 '15 at 14:08
  • Just out of curiosity, is it possible/easier to design a footprint in Solidworks and import? Certainly with tools like Solidworks' drawing tools, doing these by hand would be trivial - it just feels very painful without. – zplizzi Jun 30 '15 at 14:10
  • What the industry EDA tools need is parametric-input pad/package capability. "14 pads, 2 rows, 300mil row spacing, 75mil x 25mil pads, 100mil pad spacing." Done. There is a lot of repetition in pads, and entering the relevant data (straight from the datasheet) makes sense. – rdtsc Jun 30 '15 at 14:30
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    I hear you.. I'm a software guy, and am used to how software world has gone so open source/community. So in dabbling in PCB design, it feels like complete opposite land and jarring. I am also surprised the manufacturers aren't doing more.. they have all this information; heck, just looking at molex for an example.. you can download 3d step models of microSD connectors, but no footprints. I understand the different file formats.. but still, pick one. Seems like as more "Maker" people get into this, much of them with the OpenSource spirit..maybe there's a disruption on the horizon to this reinve –  Jul 24 '15 at 15:26

4 Answers4

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When I was working as an engineer, I wondered the same thing, which is why I decided to create SnapEDA.

SnapEDA is a CAD library of 25 million electronic components, for which we provide PCB footprints and schematic symbols. Our PCB footprints convert to Altium, OrCad/Allegro, Eagle, KiCAD, & Pulsonix.

We run a diagnostic test on each CAD file, which we'll be making public in the next month or so. This checks for different aspects that might go wrong with mappings, silkscreen overlaps, etc.

In the future we plan to expand to other forms of design data as well.

Would love to know what you think if you have some time to check it out. We love getting feedback, and everyday we are continuing to refine the product to make it even better!

natab
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  • This looks awesome! Just out of curiosity, on the front page I see a number that says 27177 footprints, while I also see (and you claim) 25 million components. Are there just a lot of components without footprints yet? – zplizzi Jun 30 '15 at 18:20
  • Thanks! Good question. Our library is 25 million electronic components (datasheets, specs, pricing etc). And our footprints have a 1-N mapping across the components. We're still working on what our exact coverage is, but it's in the millions for CAD data, and will be growing significantly this month as we work on improving our mappings. So yes, there are some without CAD data now, but when they don't have CAD data, you can easily request it from the community too (see the "Requests" page: http://www.snapeda.com/part-requests/ – natab Jun 30 '15 at 18:35
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    Ohh! Of course, silly me. That's awesome, I'll definitely use this in the future. – zplizzi Jun 30 '15 at 18:48
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    Great!! What we've learned is that engineers/designers have really personal preferences when it comes to their CAD data, so we're working on more ways to incorporate that. Even something as simple as how pins are arranged on a symbol, for example. For footprints, we are following IPC standards mainly. Keep us in the loop of how things go! – natab Jun 30 '15 at 19:07
  • Searching for "GPS" returns a bunch of things with pricing information and no footprints. [This one](http://www.snapeda.com/parts/GPST/Panduit/view-part/) doesn't even seem relevant and [this one](http://www.snapeda.com/parts/GPS-3303/Instek/view-part/) seems to be plain wrong. – David Jul 01 '15 at 11:56
  • Thanks for the feedback. We are actively on expanding our library, and we tend to do a better job with ICs and discretes. If you want to browse popular parts, you can browse the Octopart Common Parts Library to find CAD parts for a wide variety of parts: http://www.snapeda.com/libraries/common-parts-library/ As for the GPS part you pointed out, this is a bug we're aware of. Basically the way our algorithms work is we try to show related parts we think might be useful. But in this case we 100% failed; this as a high priority bug fix for us. Thanks for letting us know! – natab Jul 01 '15 at 19:14
  • There are now multiple vendors online that provide parts but I find that, no matter how many millions they say are pre-built, I can never find more then about 25% of what I need. STEP models are somewhat easier to find than footprints. – BenYL May 16 '18 at 19:24
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You've discovered the dirty little secret of the EDA industry: Thousands of engineers everywhere reinvent the wheel every day - they all create many of their sch symbols & pcb footprints from scratch. It is quite ridiculous.

However there are reasons for it, in particular no universal (or even common) file format (nor for the schematics & PCB designs either), and that's in large part the fault of the various EDA software developers, who rely on this lack of file format compatibility to keep customers locked in.

Until recently there's also never been a way to have confidence in 'random' other people's sch/PCB-footprint designs, so E.E.s err on the side of caution and make most of them themselves. But now there are some options, like snapeda.com and circuithub.com.

Techydude
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In the mechanical world a 4-40 screw, is a 4-40 screw. In electronics, we don't have that luxury. Every PCB is different. The footprint for even an 0805 resistor will be different for wave vs. IR reflow vs. hand soldering. Some boards are small and dense, other larger and sparse. It's just easier to assess the design requirements, and tailor footprints to fit them. Never mind the issue of having to go through and verify that Joe Blow's footprint he put in some library is correct, and then making it fit the design requirements.

Matt Young
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If you are willing to spend money, you can acquire the IPC footprint wizard tool:

http://landpatterns.ipc.org/default.asp

That tool is really easy to use. Literally, you just copy/paste the measure of the mechanical data furnish by your supplier and the IPC wizard take care of drawing you a sweet footprint. I made a 62 pins MCU footprint in less than 3 min with that tool. Here a little demo from youtube: https://www.youtube.com/watch?v=8V0ZfLsp8gY

If you don't want to pay for the IPC wizard, AD include a component wizard in the footprint creator, however it is more hard to use it and often you end up with a footprint that need manual rework. So you can understand that the main reason why footprint aren't online is because most people are using footprint generator therefore, it take less time to literally make a footprint than search for it on the internet.

ACD
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MathieuL
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