Need help with PCB fabrication

[DaveHardy]

I am interested in having some PCB's fabricated. I am in the process of designing a small discrete operational amplifier that the PCB's are for. I very rarely design stuff and have never designed a PCB before. I have a few problems: 1.) I can't figure out what software to use to design the PCB's. I have a copy of Eagle 5.0 and can't even figure out if there is a parts library with SOT-23's or SOIC-8's bundled with it. I understand that I'm a total noob and don't know the software, but this is silly. I saw a few videos on YouTube and it looks like a lot of people just design their own footprints!! Personally, I think that there has to be a better way or some better software that is more user friendly. Any suggestions? 2.) I can't find equivalent SMT transistors that are equivalent to their through hole peers like the LM394 or MAT01 or MAT02. Is this a red flag? Is discrete operational amplifier design a thing of the past that isn't worth dealing with? Any comments or advice will be appreciated.

[ddietz]

I've used Eagle a little, not a lot, and I do find the built in libraries either hard to search or missing things. There are ton's of free libraries out there for Eagle. That is what I usually do. Just google search for your package type or part and eagle library.

The makers of Eagle, cadsoft, have lots of extra libraries here:
Libraries | PCB Component Libraries | CadSoft EAGLE |

Good luck

[Zero Cool]

I use eagle and the FIRST thing I had to learn is to think differently. I was used to thinking 10K ohm 1/4 watt when in eagle all they care about is the package size. Did i want a 0207 sized resistor or a 0414 sized resistor? I didn't even understand what that meant at first and then i figured out OHHH 2mm wide body with holes at 7mm apart got it... ok caps, 10mm wide with 7.5mm grid got it... then things got easier.

It is frustrating when a part isn't listed. BUT many parts are the same size and often a different part can be substituted and then re-labeled.

it takes some time to set up your own library and it is really frustrating trying to figure out how to create your own part! I still haven't quite got the hang of that yet. but there are quite a few libraries built in and you just need to take some time and peruse each one and figure out where things are.

Start by looking for the library called RCL within eagle, this is a basic resistor, Cap, Inductor library. if tou still cant find what you need, look on the cadsoft website there are many more libraries you can download and add. Also some companies like Sparkfun have their own library for the parts they make or sell! that's really nice.

I have tried several other PCB programs but all of them have their quirks and none of them are great! Eagle does the best job i have seen thus far of the packages that are obtainable by the DIY'er.

[djQUAN]

Originally Posted by Zero Cool

it takes some time to set up your own library and it is really frustrating trying to figure out how to create your own part! I still haven't quite got the hang of that yet. but there are quite a few libraries built in and you just need to take some time and peruse each one and figure out where things are.

Same thing I thought before. But sooner or later, there are parts you're going to encounter that aren't in any available library. It's actually quite easy to make your own library. There are a few tutorials on the net showing how.

[DaveHardy]

Thanks for the responses guys. I'm not scared to make my own footprints. I was hoping that there was an easier way or software out there that is more user friendly.

[DaveHardy]

Thanks for the answers guys. I'm really amazed that there isn't more user friendly software available or some trade organization with a master library. Oh well. On another note, should I update to eagle 6 before I start this project?

[johnc124]

For my own personal projects I use freepcb and find it to be incredibly intuitive. It also has a good set of footprints built in, but I really prefer to make my own (which is also very easy). One tip to make sure the footprints have been properly created is to print out the gerber file for the board (or just the footprints in question) and test fit your components on the printer paper.

I should note that freepcb doesn't have a schematic capture program built in so you will need to draw your schematic in another program (LTSpice, TinyCAD, Orcad, etc.) and then export the netlist to freepcb.

[marce]

The trade organisation for ALL aspects of PCB design is the IPC
IPC - Association Connecting Electronics Industries

The standard for SMD footprints is the IPC-7351 spec.
It would be nice to have master libraries but people can make money so.
That said Farnell now own eagle and are doing a lot of the work for you...providing online library info for the parts they stock.
http://uk.farnell.com/accelerated-de...ite/dp/1872523

woops, that links for the library manager, anyway most parts are getting eagle files added, again great for DIYers and users of EAGLE. I use a IPC-7351 Wizzard from Mentor to do my footprints these days as I use one of the larger CAD packages.

[johnmarkp]

The easiest program I have found is Pad2pad. They offer it free for designing boards that they produce. I have purchased boards from them many times. They do good work. Keep in mind that it is not a powerful system. It has a few library items and a basic router. On the other hand it is very easy to use and it is intuitive. So if all you want to do is draw the board on the screen this is the program I recommend. Pad2Pad - Custom Printed Circuit Board Manufacturer

[jkuetemann]

I find Abacom's Sprint Layout to be a nice basic layout package.