How difficult it is for hobbyist to work with SMD packages? - Page 1
Forum section: electronics / projects

author: milad1234
author_rank: Newbie
timestamp: April 28, 2016, 12:44:08 am
content: Hello,I am working on an open source project that will be released for hobbyist to create their own devices at lower cost.We have to make a decision to design the PCB and select components for SMD packages or redesign for DIP packages.I am not able to find many options for DIP components.I know DIP packages are getting harder to find these days. A few years ago SMD wasn't common among hobbyist as they did not have the tools to deal with SMD chips.As SMT tools have become cheaper and it's becoming easier to use surface mount SMD reflow soldering, how difficult is it to build a home project with SMD parts for hobbyist if DIP package is not available?So in short,how would people deal with it if only SMD parts of available for the chip they need?

author: CatalinaWOW
author_rank: Super Contributor
timestamp: April 28, 2016, 01:00:56 am
content: Use large parts, avoid BGAs and fine pitch packages and you will be fine. Basic answer, if you can do it with a fine tip soldering iron and a magnifying glass you should be fine. If it requires hot air you will lose some. If it requires an oven you lose more.

author: ANTALIFE
author_rank: Frequent Contributor
timestamp: April 28, 2016, 01:07:01 am
content: Yeah as CatalinaWOW said use larger components, most people I know are fine with anything larger than an 0805 in terms of jelly bean parts. As for IC's and LED's make sure that legs are easily accessible.

author: milad1234
author_rank: Newbie
timestamp: April 28, 2016, 01:10:24 am
content: Quote from: CatalinaWOW on April 28, 2016, 01:00:56 amThanks for your response.We are thinking to use 1206 SMD Package type.Is it large enough?

author: milad1234
author_rank: Newbie
timestamp: April 28, 2016, 01:16:50 am
content: Quote from: ANTALIFE on April 28, 2016, 01:07:01 amGreat! How about 28SOIC?

author: EEMarc
author_rank: Regular Contributor
timestamp: April 28, 2016, 02:08:09 am
content: SOICs are easy to solder. SSOP at TSSOP with finer pitch are moderately difficult without a good soldering iron.I recommend using either silver or gold plated PCB for surface mount parts, particularly for finer pitch parts. The parts sit nicely on a flat surface. HASL will make them tend to shift off of the pads making it more difficult as the pads often have a rounded coat of solder on top for smaller pads.

author: Dago
author_rank: Frequent Contributor
timestamp: April 28, 2016, 04:25:00 am
content: I've never had any issue soldering any SMD package (I've avoided BGAs though). Don't even need that fancy equipment to do it, good soldering iron, good tweezers, loads of flux and a hot air station (which cost like 50-100$ nowadays). Microscope is nice to have but depending on your vision not mandatory (I only have a crappy USB microscope that I very rarely use).

author: batteksystem
author_rank: Regular Contributor
timestamp: April 28, 2016, 04:29:45 am
content: Quote from: EEMarc on April 28, 2016, 02:08:09 amFrom my experience SSOP is also okay, it really depends on the pin pitch, the larger the better. I am experienced with soldering these tiny parts with solder wicks. I think this is no problem for hobbyist if they had the right equipment.

author: ez24
author_rank: Super Contributor
timestamp: April 28, 2016, 05:04:45 am
content: Use the largest parts available

author: Ice-Tea
author_rank: Super Contributor
timestamp: April 28, 2016, 05:44:00 am
content: 0805 is fine. 0603 is still possible, but at least I have a less than 100% succes rate with those. TQFP's the same issue: with some practice they are a definite possibility but don't expect to get 100% right.

author: Siwastaja
author_rank: Super Contributor
timestamp: April 28, 2016, 06:02:55 am
content: Quote from: milad1234 on April 28, 2016, 01:10:24 amIt's too big, unless you really need it (power resistors, large caps).You lose the benefits of SMD (dense integration).Going beyond 0805 doesn't make it easier anymore, but more difficult IMO. Thermal mass increases. The easy part in soldering SMD is that the solder flows so quickly, due to small thermal masses, that it's not easy to fail in the way that many people fail through-hole components - not heating enough, or not heating all parts (pad + component lead) at the same time.When designing PCB, don't connect pads directly to planes but use thin and long enough thermal reliefs, and a 0603 or 0805 SMD is actually easier to solder than through hole. The reason is that even without proper connection between iron, component and traces, any solder that melts will touch the trace and component, transfer heat and heat up parts in < 0.5 seconds, way before flux has burned away, providing proper wetting and solder in less than a second.Going bigger increases thermal masses and also increases the risk of ceramic caps stress cracking when not solderjust right.IMO, 0603 is a very good size, even for a beginner. 0402 is too small for most beginners. 0805 is generous, and some beginners do prefer it over 0603.0805 is really the sweet spot from the ease of soldering viewpoint, given properly designed PCB. Easiest component type to solder, ever. Beats through-hole.

author: KL27x
author_rank: Super Contributor
timestamp: April 28, 2016, 06:23:39 am
content: Personally, I prefer SSOP over SOIC. But I agree, that might turn off a lot of hobbyists.As far as the passives, I think 0805 would be just as good as 1206.... As long as you include about 4-5 extra pieces of each component. If you need one, include a cut tape of at least 5 (maybe not the more expensive caps/LEDs). And figure out a good way to package and label the kit.

author: Siwastaja
author_rank: Super Contributor
timestamp: April 28, 2016, 06:36:10 am
content: Yes, if this is going to be a kit, definitely include a lot of extra passives. The beginner needs to be taught that SMD resistors cost 0.1 cents or less. No time should be spent finding "missing resistors" from the floor, or carefully counting the components. Provide a tape with 100 resistors if they need 10. That way, they'll accumulate some for their later projects, too.Also, try to minimize the number of different parts. For example, you don't usually need a 4.7k pullup for one part and 10k for another; use 10k for both. Or a 120 ohm for an LED and a 47 ohm for a mosfet gate; use 120ohm for both.

author: JPortici
author_rank: Super Contributor
timestamp: April 28, 2016, 06:43:47 am
content: "how difficult it is?"it isn't, until smaller than 0603 for passives, qfn and smaller pitch for icsyou need a proper solder iron, that is.

author: Siwastaja
author_rank: Super Contributor
timestamp: April 28, 2016, 07:04:16 am
content: Best tip is "chisel" type, 1.6mm to 2.4mm chisel tip width, something like this:http://www.vetco.net/catalog/images/XY-44-415404-1.jpg. Don't use the sharp needle type, which is a catch for beginners.

author: Bud
author_rank: Super Contributor
timestamp: April 28, 2016, 07:20:03 am
content: 0805 that is, but make sure the pads are big enough for soldering with a soldering iron. Some footprints in CAD packages are way too small and only suitable for hot air.

author: Kjelt
author_rank: Super Contributor
timestamp: April 28, 2016, 07:30:22 am
content: Quote from: milad1234 on April 28, 2016, 12:44:08 amWell reflowing at home, owning a reflow oven and solderpaste with syringe ($$$) is not that common, this forum is not a good representation of your target audience I guess.However as pointed out above by other members, a reasonably good solderer could do 0805's components without too much problems if they at least have small enough solder and good iron.But smaller smd ic's is as far as I am concerned a no go for standard hobbieists. They would short pins, and ruin your reputation with bad reviews before you sold many of them.So what you see a lot is that companies selling kits with difficult to solder smd ic's make a halfproduct: a small converter pcb with the decoupling caps and some other needed small smt stuff on it (pull up resistors 0402, crystal or so), ready to go. Something else you see a lot if that the difficult ic's are already pre reflowed on the bare pcb, so the hobbieist already has the hard stuff taken care of and can do the more easy stuff himself. However that means you as a company have to prepare the boards and make the choice to be Rohs compliant or not etc. etc. Good luck.

author: Jeroen3
author_rank: Super Contributor
timestamp: April 28, 2016, 07:41:26 am
content: SOIC and 0805 are easy. With a normal THT soldering iron (big chisel) and 0.5mm sn60pb40, add a flux pen and make it look better.0603, TFQP and (T)SSOP require more patience. People avoid these because they are small, but the trick it to let the solder do its job. Surface tension of solder helps you. I have a big chisel soldering iron and can do TQFP and (T)SOP without issues. But I use paste and air method because this is much faster.I've also seen people using hot plates (for cooking) modded with a PID controller to reflow boards.With QFN you will need paste flux and hot air. These are really difficult because you cannot inspect them without optics.Tip: use a camera to create a macro photo of your solder work if you don't own a microscope. You can zoom in using the camera. An iPhone camera is good enough.

author: tautech
author_rank: Super Contributor
timestamp: April 28, 2016, 07:43:03 am
content: Quote from: KL27x on April 28, 2016, 06:23:39 amWhy?Are they easier to drag solder?

author: Kjelt
author_rank: Super Contributor
timestamp: April 28, 2016, 07:47:09 am
content: People, AFAIU the target audience are the people that solder once/twice a year.You can not expect them to do drag solder for the first time and be succesfull, you can not even expect them to have flux (worse they put hardsoldering copper waterpipe stuff on it and ruin everything).They probably have a solderiron you plug into the mains directly.

author: Kalvin
author_rank: Super Contributor
timestamp: April 28, 2016, 07:54:00 am
content: Quote from: Dago on April 28, 2016, 04:25:00 amAgreed. Even a cheap and crappy USB-microscope from eBay is handy. Some sort of stand or arm for the USB-microscope is also very useful. A good white (LED) light helps reading the markings.

author: Siwastaja
author_rank: Super Contributor
timestamp: April 28, 2016, 07:55:43 am
content: Quote from: Kjelt on April 28, 2016, 07:30:22 amI think the reason for this is that automatic pick&place&reflow is ridiculously cheap when done in large enough quantities (hundreds of kits sold, for example), and many people are afraid of hand-soldering SMDs, and anyway don't want to spend too much time on soldering parts. Hence, it makes business sense to solder in SMD devices and leave a few big components for the end user so that they feel like they did something for themselves.

author: KL27x
author_rank: Super Contributor
timestamp: April 28, 2016, 08:24:24 am
content: QuoteYeah, but only with a $500.00 microscope, lol. SOIC pins are so big, it takes a relatively enormous amount of solder. So you kinda have to slop on the solder and the first pin gets a lot. By the end, you are running dry. With SSOP, it's just one swipe, done, nice and even.But this matters mostly for doing batch assembly. With SSOP, I can drag solder 6-12 20 pin chips without stopping. With SOIC, I need to stop to reapply solder every couple chips. Large SOIC chips are also borderline too big to see the whole chip under the scope. Larger IC's also means futzing with more tubes and trays. SSOP is very easy. MSOP even, but not too many of the chips I use come in MSOP.Doing SOIC is actually quite annoying, once you are used to soldering the smaller pitch packages.

author: IanJ
author_rank: Unknown
timestamp: April 28, 2016, 11:01:27 am
content: Hi,Eyesight is key........let's say you need to be able to focus 6" from target. If you can't, or are soldering extremely fine pitch then you need a magnifier hat. Microscope is not necessary. I have both but never use the microscope.Something like these with interchangeable flip down lens.Ian.

author: MrSlack
author_rank: Frequent Contributor
timestamp: April 28, 2016, 11:05:44 am
content: It's fine. If anything is a pain, it's not actually working with the packages, it's finding a suitable prototyping method.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: April 28, 2016, 02:41:37 pm
content: After reading the other replies I want to add a couple of more comments. I agree in general with the size ranges identified, though I have had no problems with the larger size passives, even bigger than 1206. I completely agree with the idea of including spares on the passives. You might also dedicate an area of your board for dummie connections to be used for practice. I wouldn't have thought of the issue of improper solder, but including a few inches of solder would also make sense.I would assume that in a kit, the density achievable with SMD is not a primary consideration. I would still aim on the higher side of sizes so that you can get the widest range of customers. Placing them as close together as possible will also make the kit harder to assemble. Large pads (long pads for flat packs and the like) and wide spacing will also make your kit more accessible.Skill, vision and equipment are all factors which could reduce your market. You did not mention the scale of your kit. Most kits on the market have only one or two dozen total components. As you go up size the requirements for patience and the opportunity for errors both increase, and need to be considered in your marketing plan.

author: tggzzz
author_rank: Super Contributor
timestamp: April 28, 2016, 04:09:33 pm
content: Coming back to soldering after a few decades away, I was concerned about SMD. The worry was unnecessary; they are easy and I now prefer then to PTH. My experiences and techniques are athttps://entertaininghacks.wordpress.com/2015/03/25/creating-pcbs-with-surface-mount-components/There are many similar experiences to be found on the web.I personally wouldn't touch BGAs even thought some people remove/re-ball/resolder them.Touching a ceramic component with the iron can, I believe, thermally shock them so they crack or the terminal delaminates.When soldering with an iron, the component and PCB could be at different temperatures. When cooled down that might lead to thermal stresses. Whether that is of concern will depend on the reliability you need.

author: jolshefsky
author_rank: Regular Contributor
timestamp: April 28, 2016, 04:40:23 pm
content: Stealing a couple people's other ideas (hinted-at or deliberate), I'd say to include a bit of proper solder, a small no-clean flux pen, a bit of solder wick (maybe even locking tweezers before the short bit of copper burns their fingertips), and halfway decent tweezers. The solder should be small diameter, flux core, good brand, and maybe not lead-free if you can do that. Hobbyists might not have fine solder like that around.Put the SMDs on something sticky so they won't fall all over and disappear. Tweak the layout for hand-soldering, like maybe have a bigger pin-1 and soldermask for easy tack-soldering (and to make it easier to re-melt and re-position over and over again.) And make sure all the pads extend past the package outline too. Having laid out stuff to hand-solder, I also check to make sure there's enough clearance between parts to get an iron in there (I have trouble with scale—100 mils? 2mm? How big is that really?—I guess I have a low IQ—so I need to be extra careful.)Unless, of course, you're trying to do the "SMD experience."

author: Buriedcode
author_rank: Super Contributor
timestamp: April 28, 2016, 05:32:02 pm
content: I'll add my two cents.I have had limited experience in full production runs, but lots in prototyping - everything from DIY etching to reflow, but haven't touched BGA in a while.For Hobbyist stuff, SSOP, TSSOP, TQFP is fine. For passives I generally shoot for 0805 but 0603 is certainly doable - providing you have spares on hand in-case you breath. I highly recommend a good set of tweezers, specifically fine ones, and angled. 0.6-0.7mm solder, with flux core, flux paste and/or pen, isopropyl alcohol with lint-free clothes and a stiff hair brush for cleaning.I too was a bit weary of SMD, so used to use 1206 for passives, but going down to 0805 is no step at all, and one could argue given the less solder required, might even be quicker.I have drag soldered many IC's but providing there's plenty of flux I generally get away with a tiny bit of solder on the tip, then touching the ends of the pins (where they meet the pad), solder bridges are rare, but can be handled by a bit more flux, then drawn the tip from where the pins meet the chip, outward, letting surface tension do its thing. Worst case - solder braid. I honestly think its quicker to solder SMT than DIP and requires a lot less solder.I would invest in a hot-air station too for DFN/QFN or rework/desodering. I have an extremely cheap one with the blower inside the handle. I think Dave reviewed it once and wasn't overly keen, but it did the job, and controlled the temperature. $40 and it has a soldering iron too. I've used it for 4 years and done hundreds of boards with it. The tips are pretty poor, but they are the same size as the hakko ones so replacements are plentiful. All in all, I had no trouble making the switch. Probably should invest in a microscope or magnifying glass but so far my eyes has been enough. Avoid 0402 because for the most part in hobby stuff, its unecessary.Edit: just realized it reads like a child narrating a play... sorry :/ just a quick post whilst waiting for my roast to finish

author: ez24
author_rank: Super Contributor
timestamp: April 28, 2016, 06:00:13 pm
content: You could include one of thesehttp://www.aliexpress.com/item/2016-New-Both-Sides-SMT-SMD-Electronic-Component-Welding-Practice-Board-PCB-Soldering-DIY-Kit-Skill/32595680463.html?spm=2114.01010208.3.2.MSx6iJ&ws_ab_test=searchweb201556_9,searchweb201602_4_10017_10005_10006_10034_10021_507_10022_10009_10020_10008_10018_10019,searchweb201603_9&btsid=b824452f-735f-4d7a-9a58-678eab81c5e6

author: FrankBuss
author_rank: Unknown
timestamp: April 28, 2016, 06:43:26 pm
content: I think soldering SOIC or even SSOP, TSSOP and TQFP parts, is easier than DIP, once you've learned how to drag solder, and it is much faster. But if you are targeting hobbiests who solder once a year, chances are great that they think it is hard and don't buy it. And they might be right, because with a cheap soldering iron, no flux, wrong tip, and too much solder, it can be indeed hard. Maybe pre-solder all ICs and ship it just with the passives and 3 pad parts to solder. If you decide that they can solder the ICs, too, use extra long pads, which makes it easier for per-pin hand soldering.

author: KL27x
author_rank: Super Contributor
timestamp: April 28, 2016, 07:53:53 pm
content: I think most hobbyists start out building circuits without pcbs. When you're building a circuit with protoboard and point-to-point jumpers, this is where DIP has a big advantage.The ones that progress will mostly find it easier to do even their prototyping with SMD. It's easier to rework a trace on a computer screen than on a prototype. And I have no problem reworking an SSOP board with a chisel and wrapping wire for the occasional missed detail on a 2 layer board. It's fairly easier when most of the important traces are on top and your board is flat. And you're still that much closer to a finished board with cheaper assembly costs.So you might want to factor in your expected target market.

author: tautech
author_rank: Super Contributor
timestamp: April 28, 2016, 07:58:17 pm
content: The general consensus is that SMD 0603 and larger is no problem, personally I started with 0805 and have stuck with it and need a magnifying headset for my aging eyes and find SMD relatively easy and certainly faster than TH.As yet there's been little guidance for the OP on PCB SMD layout.If you've done TH there's a different mindset needed for SMD as routing paths are not so prevalent especially if you're limited tosingle sidedPCB.Placement is more challenging, both to make routing pathways available and to be able to actually physically solder things in place. There will bemoments if little attention is paid to component layout.One might even have to define a soldering sequence to be able to access the pads on some components and this scenario should be avoided as it makes any rework a real bitch without hot air.For hobbyists there some workarounds in SS PCB to make things easier: wire links and the odd TH component can be sparingly used to open up routing pathways just as a larger SMD component (1206) could be too.After the novice has laid out and built a couple of SMD PCB's most of these pitfalls become very obvious and then are justpartof the process.

author: nctnico
author_rank: Super Contributor
timestamp: April 28, 2016, 08:25:32 pm
content: Quote from: CatalinaWOW on April 28, 2016, 01:00:56 amActually you shouldn't solder SMD packages with a fine tip. I use a 3mm (0.15") wide tip for drag-soldering TQFP packages. It all comes down to the right temperature (330 deg. Celsius) and good flux. The use of soldering wick is rare for me.

author: Dave
author_rank: Super Contributor
timestamp: April 28, 2016, 08:33:18 pm
content: My general guideline for picking parts is just go with whatever fits your purpose for the lowest price possible. TSSOP, QFN, SOIC, whatever. DIPs are pretty much out of the picture, because they take up way too much real estate, unless you actually need a DIP package (optocouplers for HV isolation, for example).My go-to passives are 0603, but that of course varies depending on the requirements. Higher power dissipation, higher voltage rating, higher capacitance - bigger package, lack of space or really small capacitances - smaller package. 0402 are still doable with a bit of effort, I haven't needed to go smaller yet.I haven't tried BGA yet, but one day I'll bite the bullet if there is some nice chip that I'll need.tl;dr Don't constrain yourself with package sizes, just try to use whatever you can find.Quote from: nctnico on April 28, 2016, 08:25:32 pmI'll second that. I only have one pointy tip for my iron and I've maybe used it 2 or 3 times. Chisel tips are the way to go.

author: tautech
author_rank: Super Contributor
timestamp: April 28, 2016, 09:07:41 pm
content: Hobbyist SMD reworkThe ease of which might be determined by one's general rework experience.As has been mentioned previously good tweezers are crucial for any SMD work.PassivesFor many of the smaller passives hot air is not required as much of the solder fillets can be removed with a sucker and components can be heated on both pads with the likes of a Hakko K series skew tip and then swept from their pads or removed with fine tweezers.These K series tips have quite long skew edge, in excess of 6mm and can easily bridge to both pads if component density is not that great to allow access.For those doing much rework hot tweezer stations or handpieces might be a better solution for passives.Actives and IC's.Well you're pretty much buggered without hot airhowever emergency workcanbe made with domestic hot air guns but with much less control and practice on scrap PCB's beforehand is advised.One last tip to minimize frustration:Use LEADED solders/pastes

author: Pjotr
author_rank: Frequent Contributor
timestamp: April 28, 2016, 09:16:44 pm
content: Hobbyists easy SMD design rules for the un-experienced:Don not follow the IPC rules for pad sizes or the data sheet dimensioning. Make the pads larger and use 1206 parts. 1206 will also fit MELF 0204 resistors, which are easier to handle. Key of success of hand soldering is using the right tools. Use a fine soldering tip at a temp of about 320 degC and solder wire not thicker than 0.5mm. Thicker is hard to dose. Keep tip clean by using a brass sponge. Don't use a wet sponge! Use of flux paste (gel type) is also a lot of help. It not only helps conducting heat but also lowers surface tension to help the solder flowing. After soldering, cleaning of the boards can be done simply in a dish washer (provided all parts are washable). Further YouTube has a load of good (and bad) SMD soldering instructions.

author: tautech
author_rank: Super Contributor
timestamp: April 28, 2016, 09:29:27 pm
content: SMD test pointsAny test connection to most TH PCB's is relatively easy and the need for miniature grabbers is infrequent but SMD test connections are more challenging.As I stick to 0805 I've found inclusion of solder-on 0805 SMD test points suits my needs by allowing connection with std scope probe hooks thereby negating the need for more complex connection methods.While you might only need test points in the prototyping stage, these can be omitted for production or even recovered for future reuse if it's a one-time build.Identifying parts of the schematic where test points are required is the key to minimizing the # required.

author: MrSlack
author_rank: Frequent Contributor
timestamp: April 28, 2016, 09:33:16 pm
content: For test points I've been snipping the leads off a massive reel of cheap resistors. Grip with pliers, rotate 360 degress, clip short and you're left with a small rectangle. Stuff that on the board and done.

author: tautech
author_rank: Super Contributor
timestamp: April 28, 2016, 09:45:35 pm
content: Quote from: MrSlack on April 28, 2016, 09:33:16 pmDo you make a pad for them or juststuffthem on a trace?If using scope probe hookssomerobustnessisrequired to prevent lifting of traces, however less if small grabbers are used.

author: Pjotr
author_rank: Frequent Contributor
timestamp: April 28, 2016, 09:58:02 pm
content: Although a bit more expensive, using of 2oz copper is way more sturdy than 1oz. Especially when rework is needed, it will peel off/tear a lot less easy.

author: KL27x
author_rank: Super Contributor
timestamp: April 28, 2016, 10:47:32 pm
content: Sidetrack galore, but Tautech's picture shows what is the most useful "chisel" in my lineup of iron tips. So much the better if it came in different sizes. Even as big as it is, I would use this over a chisel for just about anything.Hold an SMD passive so it is horizontal. Now rotate the part 45 degrees. No, your wrist doesn't do that? Mine neither. Now put the end of a chisel tip flat against the lead. Talk about unergonomic. There's only one position you can use, and at least for my bench height and such, it is not ideal.Now put an angle on the face, and voila. You just infinitely increased your range of effective soldering positions.

author: tautech
author_rank: Super Contributor
timestamp: April 28, 2016, 10:59:10 pm
content: Quote from: KL27x on April 28, 2016, 10:47:32 pmDon't you own a file?These you can buy in lots of up to 10, hack some to suit your needs.

author: m98
author_rank: Frequent Contributor
timestamp: April 28, 2016, 11:11:55 pm
content: Just get yourself a Chinese hot air rework station for around 100-200€, some flux, solder paste, a pair of tweezers, and you're good to go. Handling fine parts then just requires some practice.Successfully replaced a macbook GPU and soldered prototypes with 0201 caps with just those items. It really doesn't get much more advanced.

author: Pjotr
author_rank: Frequent Contributor
timestamp: April 29, 2016, 10:18:34 am
content: OP did ask for a way to implement SMD diy kits doable for amateurs/hobbyist familiar with TH. Enforcing costumers to invest in complicated/specialised tooling like hot air, ovens etc. will not help to market them. Working with SMD has a learning curve. So start at the beginning with hand soldering the hobbyist is familiar with. Make that easy enough with not too complicated parts, PCB's and tooling. Hand soldering is a basic skill you will need for SMD anyway.I posted a picture that has the visual impression that anyone familiar with a soldering iron can do it. If you make that impression too complicated you will blow the not already SMD-skilled hobbyist/amateur customers off.

author: tautech
author_rank: Super Contributor
timestamp: April 29, 2016, 10:35:35 am
content: Quote from: Pjotr on April 29, 2016, 10:18:34 amReally?Nah, as hobbyists we are forced to SMD, we have no options.Learn SMD and the tricks that go with it or get another hobby.It isn't hard, even for this old fart.

author: Kleinstein
author_rank: Super Contributor
timestamp: April 29, 2016, 10:50:29 am
content: SMD soldering is not that difficult. For the beginning I would start with the not so small parts: e.g. 0805 size, SOP and SOT23. Especially the passives are really easy to solder as SMD even in size 0603 - usually easier than old TH style.For fine pitch chip like SSOP and smaller it really helps to have a well made board. It can get tricky on a self etched one without solder mask.For hand soldering it is also no problem to combine TH and SMD parts.

author: Pjotr
author_rank: Frequent Contributor
timestamp: April 29, 2016, 11:23:25 am
content: Quote from: Kleinstein on April 29, 2016, 10:50:29 amVery true. And you have to convince the beginning hobbyist it isIMHO that is what OP is up to.

author: poorchava
author_rank: Super Contributor
timestamp: April 29, 2016, 11:26:01 am
content: Passives are easy to solder. I use 0603 as my standard size for production pcb, 0805 in a rare event when I etch the pcb at home. 0402 are not a problem when one is forced to use them, and but they are a pain in the ass.All ICs that have leads are same as easy, just beware of 0.4mm pitch QFPs - those can be a bitch even with a good quality pcb and lots of flux. QFNs and DFNs are doable with some practice and appropriately designed pcb and a hot air gun.BGAs are a bitch. Small ball count ones are doable if one is forced to though...Sent from my HTC One M8s using Tapatalk.

author: Fungus
author_rank: Super Contributor
timestamp: April 29, 2016, 12:56:23 pm
content: The real problem with SMD for hobbyists is that you can't just grab a piece of perf board and go to work.You need a PCB before you can even think of soldering any parts.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: April 29, 2016, 01:36:42 pm
content: You can do much the same things you do with perfboard on a regular array of footprints. You do have to put jumpers between pads instead of just bending leads over, but that's not too big a deal. But now that layout tools and boards are so easy and fast to use the times when such things are the way to go are getting thin on the ground.

author: dannyf
author_rank: Super Contributor
timestamp: April 29, 2016, 03:07:14 pm
content: It depends on what kind of smd you are talking about. SOIC, LQFP, SOT and TSSOP are no problem. 1206 is easy. 0805 is doable.On the flip side, QFN, BGA, or 0402 are way beyond my capabilities,

author: Aodhan145
author_rank: Frequent Contributor
timestamp: April 29, 2016, 03:17:06 pm
content: Blutack and a bit of time you can solder most of the reasonably sized packages. It can be frustrating at times. packages like sop soic etc. Are easy everything down to and including 0805 I would say are easy enough and I have the most shaky hands ever. A hot air gun is really helpful for packages like qfn they are doable.

author: bson
author_rank: Unknown
timestamp: April 29, 2016, 07:37:23 pm
content: Quote from: tautech on April 29, 2016, 10:35:35 amI agree with the above. In fact, once past the initial learning curve SMD isgreat: you can warehouse a bazillion different parts in a trivial amount of space; they're MUCH cheaper; the boards are MUCH smaller and hence cheaper and easier to make; they work better due to the shortened distances and MUCH smaller parasitics; they're easier to lay out because the boards aren't full of pin holes.

author: Buriedcode
author_rank: Super Contributor
timestamp: April 29, 2016, 07:48:43 pm
content: Quote from: Fungus on April 29, 2016, 12:56:23 pmWell you can use 0805 passives on stripboard.. I've done that, but with dip IC's. Sadly, perfboard/stripboard just looks so dated now. I no longer show people prototypes if they've used stripboard, even if they're fully functional, because, well, if anyone see's it, just looks shit :/

author: Pjotr
author_rank: Frequent Contributor
timestamp: April 29, 2016, 09:26:43 pm
content: Quote from: Fungus on April 29, 2016, 12:56:23 pmActually EE's are supposed to be creativeBut as said, nowadays PCB cost is that low and turnaround times short, it isn't worth the effort mostly. Although is lacks the freedom to poke around easily.

author: FrankBuss
author_rank: Unknown
timestamp: April 30, 2016, 05:49:32 pm
content: Quote from: Pjotr on April 29, 2016, 09:26:43 pmThis depends on how you design your board. You don't need to poke around if you connect a 16 bit address bus from a CPU to a RAM, but when I do something new, I place solder pin headers all over the board at interesting signals.Quote from: tautech on April 28, 2016, 09:29:27 pmGood idea, needs less space than test pin headers and really nice for scope probes, or logic analyzer probes. Do you have a Digikey part number for that?

author: tautech
author_rank: Super Contributor
timestamp: April 30, 2016, 08:01:50 pm
content: Quote from: FrankBuss on April 30, 2016, 05:49:32 pmFrank, here's the page Iborrowedthe SMD test points image from:http://www.digikey.com/en/product-highlight/k/keystone/surface-mount-test-pointsThis style was the most cost effective when I looked hard a few years back, there are nicer little "ball on a post" styles that have a clip-on lead, gorgeous they are....price too.For the above I just used a standard low density Altium 0805 footprint(extended pads), (been too lazy to make a solid one)so DRC's show broken nets so remember if using these to make a solid footprint or be sure to assign the same net to both pads.Rob

author: FrankBuss
author_rank: Unknown
timestamp: April 30, 2016, 08:51:26 pm
content: Quote from: tautech on April 30, 2016, 08:01:50 pmThanks, looks nice. A bit pricier than my current solution (through hole test points, and then soldering some silver wire to it, which you can get for a cent per cm), but this doesn't matter for prototypes.

author: tautech
author_rank: Super Contributor
timestamp: April 30, 2016, 09:01:38 pm
content: Quote from: FrankBuss on April 30, 2016, 08:51:26 pmSure, but time to drill for TH and soldering too costs money also, these SMD test points are a quick and elegant solution for PCB test connection.

author: FrankBuss
author_rank: Unknown
timestamp: April 30, 2016, 09:26:12 pm
content: Usually I use Iteadstudio, and once I created this board and ordered it from them:Was the same standard price for the required size (their "small batch" offer, because I re-sold lots of it to some C64 fans).

author: hendorog
author_rank: Super Contributor
timestamp: April 30, 2016, 10:25:11 pm
content: I think soldering SMD parts and producing a good result using an iron is reasonably difficult to people who don't have experience.The main problem I find is that you need 3 hands - one for the iron, one for the solder and one to hold the part down - Skill-wise I'm probably in your target marketSo instead of that you could instead go this way:https://www.sparkfun.com/tutorials/59Solder paste in a syringe and stencils are cheap, it produces great results so why use an iron?That method should produce a much better result - with less skills - than hand soldering smd parts would. I haven't tried it myself as I have a cheap hot air unit. I expect the results would be pretty similar though.As an smd novice I find the hot air method way better than hand soldering.Also here are a couple of tricks I found on the net which were useful to me - perhaps you could include a tips sheet in the kit?* Make ghetto smd soldering tweezers by wrapping 1.5mm wire around the soldering iron tipLike this, but arrange the wire so that the iron is one side of the tweezer and the wire is the other side:http://www.instructables.com/id/Making-a-fine-tip-for-your-solding-iron-for-SMD-so/* Lift caps and resistors by putting a small solder 'ball' on the iron and heating both ends at the same time - the part comes off instantly and lifts off with the iron in the solder ball. I only learned this yesterday and it works great.https://youtu.be/XW9aEkToX8w?t=80

author: tautech
author_rank: Super Contributor
timestamp: April 30, 2016, 11:25:50 pm
content: Quote from: hendorog on April 30, 2016, 10:25:11 pmIt's not at all that difficult, just tin one pad with solder and hold component on it while applying heat with an iron, then solder any remainin pad/s.Those thatdraghand solder IC's use this method to tack the IC in place before drag soldering.

author: hendorog
author_rank: Super Contributor
timestamp: May 01, 2016, 01:22:20 am
content: Quote from: tautech on April 30, 2016, 11:25:50 pmYep understood, but that is harder to do and produces a worse result that using solder paste and hot air. I just got my first smd pcb back and I was amazed at how easy it was to get a good result using solder paste and hot air. Conversely with a soldering iron the results look amateur in comparison.So replace the hot air with a cheap skillet and anyone should be able to do it. Actually I'm tempted to test that theory...

author: bson
author_rank: Unknown
timestamp: May 01, 2016, 07:10:40 am
content: Quote from: FrankBuss on April 30, 2016, 05:49:32 pmI usually just drop in round 1.2mm pads inline with traces to put a probe to. I also make sure I have a ground TP nearby, within 3-8mm. A via centered in the ground TP keeps the ground pin from sliding. One ground TP can be used for a whole bunch of signal TPs. But, yeah, this requires holding the probe in place; but it also works very well for RF signals and fast transitions, to check for overshoot with a < 1pF FET probe, or RIS sample for an eye diagram or such.

author: bson
author_rank: Unknown
timestamp: May 01, 2016, 07:14:29 am
content: Quote from: tautech on April 30, 2016, 09:01:38 pmThose do look really nice for low-speed signals, maybe even SPI at higher rates and USB FS perhaps. I think I'm going to start using something like that; not a bad idea at all!

author: tggzzz
author_rank: Super Contributor
timestamp: May 01, 2016, 08:29:13 am
content: Quote from: hendorog on April 30, 2016, 10:25:11 pmThe liquid flux in solder paste is sufficient to hold components in place by surface tension. But don't jog the board before soldering or while the solder is still liquidQuoteBefore investing in something something complex like that, try a saucepan with a thin layer of sand in the bottom. Cheap and, for me, 100% effective.No need to bother with a stencil, but you do need a solder mask on the PCB. Apply the paste with a small point (e.g. jewellers' screwdriver) individually to each pad.Your other points are sound.

author: tggzzz
author_rank: Super Contributor
timestamp: May 01, 2016, 08:31:52 am
content: Quote from: hendorog on May 01, 2016, 01:22:20 amI did, and it works very nicely.Seehttps://entertaininghacks.wordpress.com/2015/03/25/assembling-pcbs-with-surface-mount-components/and the linked pages, plus reference material athttps://entertaininghacks.wordpress.com/library-2/homebrew-pcb-reference-material/

author: tggzzz
author_rank: Super Contributor
timestamp: May 01, 2016, 08:36:39 am
content: Quote from: bson on May 01, 2016, 07:10:40 amWhich is, of course, easy with manhattan/deadbug techniques on an unetched board.QuoteOr use a cheap simple robusr low impedance Z0 probe, e.g. a 1.5GHz HP10020A with tip capacitance <0.7pF. Others reach 6.5GHz. Homebrew ones get reach 1GHz, see references athttps://entertaininghacks.wordpress.com/scope-probe-reference-material/

author: hendorog
author_rank: Super Contributor
timestamp: May 01, 2016, 09:24:53 am
content: Quote from: tggzzz on May 01, 2016, 08:31:52 amGreat write up.When I said anyone, I actually really meant 'anyone' - e.g. SWMBO. Who has never held a soldering iron before in her life but I think would be capable of the solder paste method as you described.

author: technix
author_rank: Super Contributor
timestamp: May 01, 2016, 10:02:36 am
content: I work with 0603 components, TSSOP and fine-line TQFP fairly regularly. I uses a 936 clone with a wedge tip, and I have 5.3/5.2 vision.

author: joeqsmith
author_rank: Super Contributor
timestamp: May 01, 2016, 03:42:32 pm
content: Looks good to me.Quote from: Pjotr on April 29, 2016, 09:26:43 pm

author: bson
author_rank: Unknown
timestamp: May 01, 2016, 07:20:58 pm
content: Quote from: tggzzz on May 01, 2016, 08:36:39 amI'd be a little careful with 500ohm Z0 probes; they're not the panacea they're often made out to be in this forum. The fundamental problem is they tell you what the signal looks like when driving a 500ohm load, not the actual load in the circuit. An LVC signal can look incredibly clean, but the actual input isn't 500ohm; in fact the input impedance of LVC logic varies with voltage due to its complementary nature. A Z0 probe isn't necessarily a good option for a signal between two endpoints where it can't easily be characterized as a transmission line. LVC overshoot happens because the input impedance skyrockets as the voltage goes up, but the actual charges involved may be small and can just vanish against a 500ohm load. For uses like eliminating digital-section noise in a mixed-signal circuit, a high-impedance active probe really is a key tool.

author: tggzzz
author_rank: Super Contributor
timestamp: May 01, 2016, 07:41:09 pm
content: Quote from: bson on May 01, 2016, 07:20:58 pmNothing is a panacea of course! But basically I agree.Don't forget they don't have to be 500ohm; I have 1k and 5k variants with the obvious gains.