thanks for your response @davidsrsb
I have had unsteady hands all of my life; mild “essential tremor”. I am 68. When SMT was introduced, I was intimidated by it. But nowadays I can hand solder 0603 chips routinely. One recommendation is that I like to use a relatively small 0805 footprint for my 0603 chips.This provides more room on the pad for the soldering iron tip.
0402’s? No. I have done them, but half the time I lose the chip in the drop of solder on the end of the soldering iron.
In my opinion, SMT is often easier than thru hole because you do not need to worry about holes filling with solder. I think it is much easier to change values of an 0603 chip on the board than to change values of a 0.25W thru hole resistor. So dive into it with courage. I do recommend a desolder tweezer. Two soldering irons can also work to heat both pads at the same time.
In my lab I stock 0603 and 1206 resistors but not 0805s, with a few exceptions for milliohm values. If you have a small 0805 footprint, it might be easier to solder an 0603 chip onto those pads than an 0805.
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I would say once you get comfortable with hot air, you start looking at your PCB’s with a twisted sense of size, everything just ends up looking stupidly large, and you may get into a habit of packing things into smaller and smaller sizes
Makes for some fun, but annoying when you then realize the PCB needs to be 5x bigger for the mounting holes
E.g. 0201 10nF capacitors just so perfectly fit across 0.5mm QFP package pins, but it is not an easy task to place them or rework them if you ignore the courtyards, if you follow them, in most cases things will be easy to assemble with sharp tweezers,
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That usually requires a paste stencil, too. I have experience only with steel stencils, but I know it can be frustrating to learn to use it. 0402 can be soldered with an iron and the stencil isn’t needed. 0201 may barely be possible with an iron, too, but only with a good microscope (and good component placement as you said), and I don’t recommend it. Additionally it may be surprising that going to 0201 from 0402 saves relatively little space. With those sizes the tracks and especially vias take quite much of the space in the board and 0201 is worth it only if you can go for really thin tracks and smaller than standard vias – and actually really need all the space you can get.
As for the original question – why not just go after their recommendation. I think the opinions in this thread confirm that suggestion. The question of 0402 vs. 0201 is interesting in its own right, but not relevant for that.
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Not really, just a lot of stubbornness,
Pre-tin pads, add a dot of gel flux and poke stuff when it doesn’t self align correctly,
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I used to use for it one 110W trafo soldering iron and one soldering iron with sharp tip. When I have the element (typically 0603) taken out of PCB and between then I switch off the trafo soldering iron and the element stays at it and it is cold at once. Then I take tweezers to my second hand and take the element off the iron (by switching it on for a second).
In past (when I didn’t had those iron with sharp tip) I have also done special shaped wires used with trafo iron to heat both ends of elements like 0603 (I had also special shapes (with one leg bigger) for SOT23 and SOT323).
We switched from TH elements to 1206 and than to 0805 and then to 0603 and we finished that process in previous century. Now we use mainly 0603 and some 0402 (mainly 100n blocking capaciotors to place them close to IC pin pairs (VCC+GND) and to not block tracks from next pads.
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Many KiCad libraries have alternate hand solder footprints with bigger pads that allow the iron to touch the pad
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But that way I don’t get to re-invent the wheel! 
Seriously I have dimensions that I have used previously with other pcb layout software, and it is not a big deal to make my own footprints for these SMT parts. I only need to make each one once. Another footprint will fit anything from 0603 up to 1210 for hand soldering.
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I would definitely recommend using 0603 (imperial size) rather than 0805. I consider 0603 a good general purpose size for at lot of things, and yet they are still easy to handle with manual soldering, that be iron or hot air. Just my comments, although I know I did not add much more information here to all the other replies
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It also seems to be the case that it is easier to get 0603 compared to 0805. Was especially noticable during the MLCC crisis.
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Yes, 0805 and larger is verging on obsolete/specialist.
The snag with the smaller parts in some of my projects is low voltage rating even when the power rating is no problem. Most volume consumer products are built with 0402 or 0603
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For me, 0603 is comfortable to hand-solder and all my designs use 0603 parts (if possible).
I generally use paste and a reflow oven most of the time but for prototypes I’ll often hand-solder first ( unless there BGA parts involved).
I use Kester 959T liquid flux in a squeeze bottle with a needle for SMD work. Can’t stress how good this stuff is for hand-soldering or touching up after a bad reflow. Also, high-quality solder is extremely important. I use Chip Quik SMD291AX paste for reflow and Kester 24-6337-8806 for hand soldering. Kester solder is the best you can buy in my opinion. I also have a Hakko 915F solder station with a collection of different tips. I find for soldering 0603 caps and resistors a chisel tip works best and for QFP and SOIC parts a bent conical (or flat) tip with a reservoir works best.
I’ve been able to successfully hand-solder QFN but I don’t recommend it.
With 0402 I’ve hand-soldered a few times but avoid caffeine because hand-shaking can be disastrous. 0402 parts often get stuck to the iron tip or go flying across the room never to be found again. Definitely need a 10x microscope or you can get +7 reading glasses on eBay which work well.
0805 looks enormous to me now and I rarely use this size in my work unless it’s a large value capacitor
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What I have seen is that 0603 and smaller is still quite common for “everyday values” and 1206 / 1210 are common for parts that are currently impossible to cram into an 0603 (very large capacitors, high voltage ratings, high power resistors, etc). 0805 I guess doesn’t offer enough of a useful middle ground
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they suggest me to use 0804 SMD Packages.
Here are I think important points to consider before applying a one size fits all rule (which usually is a bad idea):
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It all depends on what your approach to soldering these SMD components is: I use DIP only for quick prototyping, but found 0603 easier to solder than bigger ones like 0805,1206 when using solder paste with my SMD rework station because you can cover more components with your hot air in a given area. Now when using a soldering iron, of course 0805 or even 1206 can be a better choice…
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You should be careful not to use always your preferred size (i.e. 0603) but instead, always check the datasheet of your component during your design phase, as many smaller components have different characteristics.
The most common mistake being using a small resistor ref. that is 1/10W when your design needs at least 1/8W …
Same for capacitors, always check the max voltage of your particular package (should be at least twice what your design is supposed to use by default).
- Make sure you use hand soldering special footprints when you use a soldering iron
SMD soldering is both fun and efficient with a bit of practice, good luck!
-Fab
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I found 0603 letting me to get smaller PCB still enough easy to hand solder.
It is popular rule used for electrolytic capacitors. They are typically used at supply input and you should expect some overvoltage there during surge.
But for ceramic capacitors in the circuit where you don’t expect overvoltages I have seen few times the info that you can use them up to their specified voltage. Not sure at that moment as many years passed but as remember I sow in the TaiyoYuden specification that ceramic capacitors were tested for 2,5 times the nominal voltage.
So if you need 10 uF at 5V regulator output I think you can use ceramic 0603 10u/6.3V X5R capacitor.
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You can always try, but finding shorted capacitors is a real *&^%$#@!
I have no trouble at all with 0603, or probably even smaller, as I have a decent stereo optical microscope. I’ve heard several others complaining (mainly on youtube) that 0603 is already getting hard to solder because they are too small to see properly. This is especially true if do do not have a stereo microscope (Around EUR400) and your eyesight is getting less (often worsening with age, after about 30 years it seems to start slowly). A cheap partial solution is to use a lot of light. And I mean an stupendous large amount of light. When there is a lot of light, your iris contracts, and a smaller iris results in a “pinhole camera” effect on your retina and this gives a sharper picture.
To give a reference for a stupendous large amount of light
Bright sunlight is around 1000W per square meter (perpendicular to the sunbeams), and efficiency of LED’s is no better then 20%.
Your brain fools you. It does not reveal to you that your eyesight is getting fuzzy or a bit vague. It takes a conscious effort to focus on that.
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Since at least 10 years I need glasses to read.
I don’t have a microscope - I am using the table lamp with increasing glass.
I have just done experiment by looking at PCB directly and through this glass - the PCB looks being 1,5 times bigger.
Normally I don’t assemble our PCBs, but when I had to select elements for RFID antenna circuit I desoldered and soldered 0603 capacitors more than 200 times a day.
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These were just examples to incite beginners (or beginners with SMD) to always check the datasheet when using a package.
Now if I can understand that sometimes it can help your design a lot to be minimum with your maximum voltage specifications, it is not something I would recommend to someone starting.
Especially for high voltages, people should be even more careful (I saw a cap exploding and traversing a lab wall and the guys that dimensioned this cap did not do a great job and could have killed or caused a lot of harm to one of us…)
Finally, I would avoid as much as possible to make my design sensitive to a particular manufacturer for which you know about their testing, because I like to be able to provide component substitutions.
But again, there is not a one size fits all rules and reading you, I am sure that you know what you are doing when you apply a more relaxed rule …
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Many ceramic capacitors lose capacitance as the voltage across them approaches the maximum rated voltage. It’s often suggested that if the capacitance value is at all important you should select one rated at twice the expected working voltage.
When I made my first SMD board I was very hesitant to use 0603s. My last design used a mix of 0603 and 0402 parts and I didn’t find the 0402s that much harder to mount.
However, I have a stereo microscope designed for board repair and a cheap knockoff hot-air soldering system. I really can’t imagine placing these smaller components with a soldering iron.
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