General > General Technical Chat
Come in through-hole components your time is up!
rob77:
--- Quote from: Red Squirrel on May 05, 2017, 11:54:04 pm ---You need a very good microscope (not just zoom, but optical clarity, focus distance etc) and very precise tools. I've attempted even "large" SMD parts but without proper equipment it's very hard.
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let me disagree.. you don't even need a microscope. a cheap 4x magnifying glass is enough (the one old ladies use for knitting is good enough). SOIC packages and 1206 passives are doable without any kind of magnification. furthermore you need a pair of sharp tipped tweezers, solder paste and source of hot-air for soldering, if you're careful you can even use a hot-air gun for paint striping (low setting and heating board from 10-15cm till the paste flows). so no expensive equipment needed.
--- Quote ---You pretty much need to have proper circuit boards for them too, trying to solder them "free air" is much harder and more tedius. They move around too much and with only 2 hands you can only do so much. With through hole at least you stick them in the protoboard and flip them and the weight of the protoboard is enough for it to stay put while you solder.
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fully agree you have to have proper PCBs for SMD. that's why it makes sense to make your own PCBs (unless you want to wait weeks for your cheap boards from China)
--- Quote ---It's not so much that SMD is not doable it just takes much more effort if you're not properly equipped.
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actually the effort is on par with building on proto-boards.. more effort goes into designing and making the PCB and much less effort into actual assembly, but at the end of the day it's the same amount of effort.
daqq:
I'd say that connectors (and sockets or other potentially mechanically stressed components) will be available as through-hole (or at least have mechanical holding pins) - there's just no reasonable way to replace the mechanical stability this provides.
Also, the heavier parts will be mostly through-hole - large ass capacitors, transformers, a lot of what makes a PSU.
Also, the power parts seem to be more easily mountable onto heatsinks when they are through-hole.
That said, in the future there will be less components available as through hole devices, for already stated reasons.
Zero999:
--- Quote from: hans on May 06, 2017, 09:57:01 am ---I wouldn't even get too dragged along into using flux for every solder joint. The stuff smells, sticks, makes a giant mess, and with good fresh solder there is also flux inside it. Only for QFP or QFN chips I will use flux to make sure the soldering job will succeed.
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I don't see why some people feel the need to use a load of flux.I just use rosin cored solder for everything, The only time I need extra flux is when the board or components are badly oxidised.
Red Squirrel:
--- Quote from: rob77 on May 06, 2017, 02:28:22 pm ---
--- Quote from: Red Squirrel on May 05, 2017, 11:54:04 pm ---You need a very good microscope (not just zoom, but optical clarity, focus distance etc) and very precise tools. I've attempted even "large" SMD parts but without proper equipment it's very hard.
--- End quote ---
let me disagree.. you don't even need a microscope. a cheap 4x magnifying glass is enough (the one old ladies use for knitting is good enough). SOIC packages and 1206 passives are doable without any kind of magnification. furthermore you need a pair of sharp tipped tweezers, solder paste and source of hot-air for soldering, if you're careful you can even use a hot-air gun for paint striping (low setting and heating board from 10-15cm till the paste flows). so no expensive equipment needed.
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The issue I find is mostly trying to get everything to stay steady and making movements that are tiny enough. The natural shake of my hand is much higher magnitude than the size of most SMD pins. I guess you could consider the shake as "noise" and what you want to solder the "signal". The "noise to signal" ratio becomes very high when trying to work at such small parts. I can see fine with magnifier, I just can't actually maneuver that precisely. Eventually I get it, but I find it takes much more effort. I don't have any fancy tweezers or anything like that though, most of the stuff you buy these days is garbage crap from China, I have some tweezers but they don't really seem to pick up or hold stuff very well.
One thing that's crossed my mind is to have some kind of spring loaded set of metal pins/fingers that can push down on chips, if you can have something keep it steady on a thick heavy piece of wood then you can solder magnet wire to each lead without the chip wanting to go everywhere.
I guess bottom line is once you can find a proper way of doing it, it's probably not that hard after all. I do see that a lot of ICs are only in SMD so by trying to do only TH I'm really limiting myself in selection. I have these 30amp current sensors that are SMD and I under estimated how small they are when I ordered them. I'm surprised you can even pass 30 amps through something that small! You normally need like #10 conductor for 30 amps and the whole chip is smaller than that.
rstofer:
--- Quote from: Red Squirrel on May 05, 2017, 11:54:04 pm ---I'm in the same boat myself, I use mostly through hole and would hate to see it go. As a casual hobbyist I'm just not equipped for SMD. You need a very good microscope (not just zoom, but optical clarity, focus distance etc) and very precise tools. I've attempted even "large" SMD parts but without proper equipment it's very hard. You pretty much need to have proper circuit boards for them too, trying to solder them "free air" is much harder and more tedius. They move around too much and with only 2 hands you can only do so much. With through hole at least you stick them in the protoboard and flip them and the weight of the protoboard is enough for it to stay put while you solder. It's not so much that SMD is not doable it just takes much more effort if you're not properly equipped. But their real advantage is in mass automated production as threw hole is kinda a pain for that.
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I guess I have to disagree. Surface mount is faster and easier than through-hole even for me, an aged hobbyist. I squirt some solder paste on the pads, place the parts and cook the board in one of two ways. The cheapest is to use a hot plate where the flat surface is sufficient for the size of the board. Like this:
http://www.target.com/p/oster-single-burner-hot-plate-ckstsb100/-/A-13773420
The second way is to modify a toaster oven (mine is the now obsolete Black & Decker InfraWave with an Arduino controller) by adding controls and, in my case, sheets of insulation:
http://www.rocketscream.com/shop/reflow-oven-controller-shield-arduino-compatible
The third possibility that I sometimes use is to just place the parts in the solder paste, hold them down with curved tweezers and hit the junction with a soldering iron. This is pretty slow compared to either of the other methods.
SMD is NOT an issue. All you need is solder paste, flux, a decent soldering iron and, perhaps, a hot plate or toaster oven. Some people use the hot air rework tools to good advantage. I haven't found mine to be helpful.
I don't even bother to buy stencils, I just dab the solder paste on by hand.
--- Quote ---If it comes to a point where it's hard to find stuff in through hole I suppose the norm is going to be to get break out boards made out for prototyping etc. You can buy them but they're kinda spendy if you want a lot of them but with how cheap it is to get PCBs made you could make your own. I need to sit down and learn KIcad properly so I can do that myself. I have a couple parts that I thought would be easy to deadbug but tried and it's super tedius to do. I'm sure I'd get it eventually but with proper boards it won't be as hard.
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Adapters for prototyping work well. They are just as hard to solder.
I don't have a microscope but I have been getting a lot of use out of my Optivisor. I have two, one is a little more powerful but the field of view sucks. I have to get my head right down there.
Drag soldering is another option. Just smear the pads with flux, place the part and hold it down. Put just a tiny bit of solder on the tip and hit the corner pins. Once the device is locked in place, put a little more solder on the tip and run it down the pins. It's amazing how well drag soldering works. Google for videos.
I buy all my PCBs from ExpressPCB. As a result of the MiniBoard concept, my boardsize is limited. Using SMDs means I can still build projects with many dozens of components. ExpressPCB software is probably the least sophisticated on the market but it is very easy to use and autorouting never makes a mess. It doesn't have autorouting...
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