Electronic – Issues with going to small passives


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?

Best Answer

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.