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I'm going to be working on my second major design where size is the number 1 goal. What are the theoretical issues going with 0201 or less for resistors/capacitors, besides soldering difficulties?

Gustavo Litovsky
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Vanush Vee
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  • One issue could be the power ratings of the resistors. Typical power rating for 0201 resistors = 0.05 W, says [Wikipedia](http://en.wikipedia.org/wiki/Surface-mount_technology). – m.Alin Jan 23 '13 at 00:58
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    I think I cut size more on my second major design as my layout skills improved mid-project than I would have by switching from 0402/0603 to 0201 and smaller. Food for thought. – Joe Baker Jan 23 '13 at 01:15
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    Speaking as a person who does a lot of PCB design and prototype assembly by hand, 0805 is dead easy to work with and 0603 is only slightly harder. However, 0402 is a major pain, and I can't even imagine trying to do 0201 by hand with an iron. Also, once you get below 0603, the vias and other physical aspects of the PCB begin to dominate the density of the layout anyway. Unless you're building something like a cellphone motherboard with full pick-and-place and reflow support, I'd stay with 0603 and above. – Dave Tweed Jan 23 '13 at 04:20
  • I regularly work with 0402. They're not that bad, especially if you use solder paste or simply solder each side at a time. A microscope is especially helpful. – Gustavo Litovsky Jan 23 '13 at 05:36

1 Answers1

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The Issues are not theoretical. Many assembly houses have trouble or cannot do 0201 (much less anything smaller) given that their machines don't support it. Even if it does, there is a high likelihood of the machines making mistakes (called attrition), which is why you need to provide an extra 5% more components to ensure the attrition is covered.

0201 components don't have the power dissipation and current carrying capabilities of the 0201 parts, as you can see from your specs. So you have to be very careful that they won't carry anything above their power rating.

Clearly you'll need to find 0201 elements at the right inductance or capacitance and this can become difficult, impossible, or very cost prohibitive.

Capacitors and inductors at that size do have less parasitics, so that's about the only plus (aside from size) that you get.

A few other not so critical issues are that attaching test points/wires directly to components is much more difficult since there is little mechanical strength to hold anything.

So to summarize, be extremely careful about component selection.

Gustavo Litovsky
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  • With higher voltages, maintaining minimum lead spacing will also be an issue. – ndim Jan 23 '13 at 06:24
  • @ndim: Since the op mentioned that he wants to make a design smaller, it's usually unlikely this has a high enough voltage to make this an issue, but you never know. – Gustavo Litovsky Jan 23 '13 at 07:56