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Questions relating to designing PCBs
By jim bone
#162622
Hi,

This is my first time designing a PCB. I will likely be using OSH Park for manufacture. My application is a low power oscillator run off a 9v battery. I have a few questions:

1) For passive SMD components what generally is the standard package size? I see 1206 come up a lot on google searches, but for caps over 1uf it isn't clear what is standard.

2) I'm planning on putting some through-hole pads to attach my battery supply. Is this a good approach? What size pad and through-hole is recommended? What is the corresponding eagle part? I see some options under wirepad and solpad.


Hope someone can fill me in!


Thanks,
James
User avatar
By viskr
#162646
0603 is kind of the sweet spot for components these days and easy to solder once you get some practice

62 mil pad / 40 mil hole is what I use for 0.1" headers, DIPs and wires in general

1uF caps are available in 0603, actually up to 4.7uF are still reasonably priced. For larger sizes step up to 0805 for ceramic. These values are mostly being driven by cell phone volumes, but they will routinely use 0402 and 0201 (don't even think about 0201for hand assembly). For bulk capacitors look to tantalum that come in size codes A,B,C,D or aluminum which are in round cases.
By jim bone
#162647
Great, thanks for the info.

I just realized that there are metric and imperial package codes, and that some codes co-exist in both but for different sizes. I assume you are using imperial? Is that the default convention if not specified?
User avatar
By Ross Robotics
#162660
I use 1206 exclusively. It isn't much bigger than 0603 and a lot easier to solder by hand.
By trialex
#162671
Normally it's easier to find the package you want to use at the supplier first, that way you don't get stuck if no one sells the combination of physical size and electrical rating you need.
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By Ross Robotics
#162672
Just for the record, I use http://www.digikey.com/ for most of my components. For the more common parts, I use Ebay.