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Using SMD to make the PCB smaller is an easy choice but I'm wondering if using mainly 0805 size is really worth it compared to 1206.

I don't want to store a mix of both.

These are some pro and cons, can you help adding some more to help deciding.

  • Soldering is a bit easier with 1206. (with my bad eye's all bits count)

  • Higher maximum power. 1/4W vs 1/8W --> lower temp. change for the same power.

  • PCB will be a bit bigger with 1206 (~10%??) but I'm not sure, since you can easily run a signal under a 1206 saving 2 vias. The board is probably more determined by the big components anyway (I assume) If µCurrent would use 1206 instead of 0805 wouldn't the PCB have the same size?

  • Price/Availability is the same now for 1% resistors, 0.1% seems to be better for 0805, will this stay this way or are they planning to fade out 1206 in the next years?

I would go for 1206 for all SMDs mainly for easier handling but I'm not sure if I'm missing something important?

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    \$\begingroup\$ What IC packages do you tend to use: DIP, SOIC, TSSOP (in order of decreasing pitch)? What kinds of devices are you primarily making? Are they strictly one-offs, or do you suspect that some them may hit production with quantities greater than few dozen? \$\endgroup\$ – Nick Alexeev Nov 23 '14 at 22:53
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    \$\begingroup\$ I find both sizes massive these days. I work almost exclusively in 0603 unless there is a specific need for bigger. I can use 0402, but I do find them a little fiddly, and the lack of markings on resistors can be a pain. That's with both hand soldering (iron), and reflow soldering (hot air blower or oven). Why waste space on big components when you can do the same job just as easily with smaller ones? PCB space is money. \$\endgroup\$ – Majenko Nov 23 '14 at 23:12
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    \$\begingroup\$ On the one hand, there can certainly be good answers to this question, on the other, it seems likely to invite discussion rather than straightforward answers. OP, would you consider making this a community wiki? \$\endgroup\$ – The Photon Nov 23 '14 at 23:16
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    \$\begingroup\$ For capacitors, the smaller package size limits not only capacitance but also working voltage and physical thickness. But most likely can standardize on a smaller number of values, e.g. 0.1uF 1uF 10uF 100uF at WV=2x each of your supply voltages. This is a much smaller problem than keeping every 1% resistor value in stock. So I get the sense this question is mainly about stocking 1% resistor values. \$\endgroup\$ – MarkU Nov 23 '14 at 23:37
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    \$\begingroup\$ In many cases you can use two 1/8W resistors in series or parallel to get 1/4W to keep temperature low. But in some designs where you need a lot of 1/4W resistors that may be bad idea. \$\endgroup\$ – Kamil Nov 24 '14 at 0:09
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  1. I think that you are not gaining a lot oft space using 0805. Of course it's depend on the size of your circuit. if it'really big board then may be.
  2. For the power 1206(1/4W), 0805(1/8W). if accuracy in design is well done just check for Rpower =(3/2)*PowerCalculate. Must of time it's really enough to be 150%. some people choose 200% of the power dissipation.
  3. If you are doing Hand Soldering, i suggest your board is not as big as many as i saw in my live. this say that 1206 can be good if you haven't good experience in SMD soldering. For information companies must of time are using 0603 (other 0805) . There are the must use for standard board. For PCB with BGA they go for 0402 because of board size constraint and routing complexity.
  4. About prices. I think there are no price fixed for any component. There are many companies that make component, and sometime can be different by companies.
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I think (based on prices and availability) 0603 is a better choice for the future, and use 0805/1206 or bigger where necessary. 0603 is pretty easy to solder by hand and any assembly house can handle it with high yield. 0402 is a bit cheaper for bypass capacitors in typical sizes if you don't mind the 10K per reel granularity of buying by the reel.

If you have to pick between 0805 and 1206, 0805 is better, however if you're into only small quantities and/or hobby you may be able to score cabinets loaded with 1206 parts for essentially nothing (as I did) since companies doing forward-looking production have been dumping them for some time now.

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