SMD size 1206 vs 0805 soldering at home - Page 1
Forum section: electronics / projects

author: KedasProbe
author_rank: Frequent Contributor
timestamp: September 01, 2012, 01:06:53 pm
content: Hi,Using SMD to make the PCB smaller is an easy choicebut 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?Thanks

author: Rerouter
author_rank: Super Contributor
timestamp: September 01, 2012, 01:16:07 pm
content: it is still very easy to fit a trace under an 0805, as most boards these days have silkscreens there is no issue with creepage,as for soldering them, as long as you maintain a reasonable spacing, 0805 is very easy, its 0603 that is hard on most, (i prefer maintaining 2.5-3mm eade to next edge spacing between smd passives) but yes you are correct on the power level, but it comes down to the project, if you are working with higher power stuff in large quantity you use larger passives, if you work with low power you use small pasives, and if its just for hobby use, you prefer one and hold onto or use larger ones as needed,

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: September 01, 2012, 02:14:29 pm
content: There is no real difference between 0805 and 1206 in terms of hand-solderability as the pad sizes are not much different - the difference between 0805 and 0603 is much more significant, as is the difference betwen 0603 and 0402.1206 is pretty much obsolete for resistors except where higher power rating is needed. 0805 is a good "default" size until you need something smaller. Pricing and availability is likely to be better on 0805 then 1206

author: DarkPrince
author_rank: Regular Contributor
timestamp: September 01, 2012, 04:38:24 pm
content: I suggest getting used to 0805, as it seems the most common and you may have issues finding the larger versions of the component you need, or at least the price will go up because it isn't as mass-produced (though it depends, but why buy less than 100s at a time). At least that is how I felt when I was selecting my SMT components.

author: ablacon64
author_rank: Frequent Contributor
timestamp: September 01, 2012, 07:07:35 pm
content: As the size of the resistor is related to its wattage the project will require different sizes now and then. 0805 is really the most used size anyway.

author: westfw
author_rank: Super Contributor
timestamp: September 01, 2012, 11:39:01 pm
content: I bought a bunch of 1206 resistors from eBay, but I'm finding them overly large. a 1206 footprint is slightly larger than a vertically mounted TH resistor :-(

author: nctnico
author_rank: Super Contributor
timestamp: September 02, 2012, 12:22:19 am
content: IMHO 0603 is about the smallest you can conveniently solder by hand. Nowadays I'm soldering quite a lot of 0402 components but it is difficult to check the solder joint with the bare eye. If your soldering skills aren't that good I'd suggest going for 0805. For self made PCBs I often use 1206 because there are very easy to solder so I can work quick.

author: westfw
author_rank: Super Contributor
timestamp: September 02, 2012, 04:01:54 am
content: The other thing is that a 1206 (or even 0805) package is really large compared to a 0.5mm pitch IC package. If you're trying to sprinkle bypass caps and IO termination resistors around your LQFP64 or something, you probably need something smaller.

author: poodyp
author_rank: Regular Contributor
timestamp: September 02, 2012, 09:30:36 am
content: I've done 0402 before, it was a little sloppy because the pads were for 0603 LEDs, but I had no 0603 resistors. I have no fear of doing it again, but would prefer using solder paste instead of sticking solder on my iron and using liquid flux to make it stick.

author: KedasProbe
author_rank: Frequent Contributor
timestamp: September 02, 2012, 09:33:47 am
content: I don't worry about shaking, my problem is seeing what I'm doing.I realise that I will need some webcam magnification or similar for SMD ICs anyway.So I'm going for 0805 (if power permits)Thanks

author: shadewind
author_rank: Frequent Contributor
timestamp: September 02, 2012, 08:13:58 pm
content: I find 0603 pretty simple to do by hand and I can do 0402 without too much hassle but I prefer to use solder paste and hot air in that case. I just use a loupe to check joints when in doubt.

author: AndyC_772
author_rank: Super Contributor
timestamp: September 02, 2012, 08:21:23 pm
content: I think by its very nature, this question is one which is always going to boil down to an individual's personal experience and preference. Usually there's no significant price or availablility difference, though you may find 1206 a tad more difficult to find simply because they're not so popular.I tend to use 0603, because it's the smallest size I can reliably and easily solder by hand. I could use 0805 which is a little easier to handle, but since I design products commercially and board space is often an issue, I don't want the hassle of maintaining separate component stocks and libraries.

author: ablacon64
author_rank: Frequent Contributor
timestamp: September 02, 2012, 09:15:56 pm
content: Quote from: shadewind on September 02, 2012, 08:13:58 pmI don't use solder paste cos there's not a refrigerator around, but I get the same result tinning the pads with a "generous" amount of solder (it looks like a small solder cushion), applying a generous amount of resin flux and applying hot air. When the solder melts I quickly slide the component sideways to the pads and keep the heat a little bit so the surface tension does its magic.

author: shadewind
author_rank: Frequent Contributor
timestamp: September 02, 2012, 09:46:55 pm
content: Sounds like a bit of a hassle but great if it works for you

author: ablacon64
author_rank: Frequent Contributor
timestamp: September 02, 2012, 11:40:36 pm
content: Quote from: shadewind on September 02, 2012, 09:46:55 pmWell, I mainly fix damaged equipment, so I have just a few components to exchange, if I was into product design sure I'd be obliged to use solder paste.As for the method, it's really fast, I'm used to it.