Surface Mount Soldering - Page 1
Forum section: electronics / beginners

author: RJDog
author_rank: Contributor
timestamp: February 10, 2017, 03:39:20 am
content: So I've only ever done through-hole device soldering, and I think I'm... pretty okay at it. But now I'm working on a prototype that uses a couple chips that only come in surface mount packages. I've been watching a lot of videos about hand soldering SMDs and it doesn't look too scary... I guess there has to be a first time for everything.So two questions; first is related to package selection. I'm leaning towards SOIC... the relatively large 1.27mm pin spacing seems attractive to me as a first timer. Am I on the right line of thinking, or are smaller pin spacing deceptively easier? My other question is around the other chips being used... coincidentally all of the chips have a SOIC package. Should I have everything on the board be SOIC, under the theory that I might get "good" at it (about 8 chips on one board, plan to make 2 prototypes) or should I stick to through-hole for those that come in that package?

author: ebclr
author_rank: Super Contributor
timestamp: February 10, 2017, 04:03:33 am
content: The best advice, buy a solder paste stencil for your board, and at leats a hotair if a Profile furnace is to muCH$$$ for youIf wana do by hand, be prepared for a lot of frustration, and ugly soldering

author: mrpackethead
author_rank: Super Contributor
timestamp: February 10, 2017, 04:21:46 am
content: 1.27mm SOICs are very hand-solderable with reletively basic tools and equipment.FLUX is your friend, and suitable tips for your iron. A set of low cost tweezers is about the only other thing you need. You might want some kind of magnifying glass.As for technique, heres a nice little video.Other SMD parts have some other techniques that can be used... its all just about practice and trying it..Once you get the hang of it you'll wonder why you did TH for so long as SMD ends up being so much quicker.

author: tautech
author_rank: Super Contributor
timestamp: February 10, 2017, 04:25:42 am
content: Quote from: RJDog on February 10, 2017, 03:39:20 amWelcome to the forum.I took the leap into SMD ~5 yrs ago and it's not at all hard IMO. For prototyping and entry into SMD SOIC is a good choice......drag soldering, each pin one at a time or reflow are all common methodologies for the novice. While hot air and paste can be used it's better suited to rework.In PCB layout stage trace paths are harder to find due to the smaller components without using double sided or multilayer boards but for simple one layer layouts some judicious use of the odd TH component can provide pathways for traces that might not be there with only SMD population. If your PCB CAD package has them, use bigger SMD pads for prototyping to make getting a nice solder fillet easier when hand soldering.If your prototype is just a proof of concept it it shouldn't matter which package you use.

author: Monkeh
author_rank: Super Contributor
timestamp: February 10, 2017, 04:26:17 am
content: Quote from: ebclr on February 10, 2017, 04:03:33 amEnough with the FUD, it's a giant 50 mil part.SOIC parts are pretty much trivial, don't even need any extra supplies for them. You'll find if you actually challenge yourself and try new packages, you get good fast - I started out with DIP and moved to doing 0.4mm QFNs and now the occasional BGA in very short order. You'll never learn to do them if you never try!

author: Gregg
author_rank: Super Contributor
timestamp: February 10, 2017, 04:28:12 am
content: Watch a couple of Louis Rossmann's YouTube videos; he does a lot of SMD soldering. (I think he uses way too much flux, but his videos may show you some things you may not realize at the start.)If you only have a few SMD components per board and not a whole lot of boards, a good temperature controlled soldering iron will do the job. I would definitely go with the larger SMD components if you are starting out. If you can, use the lead solder Sn63/Pb37 from a reliable source and use quality flux. Tin the pads first. If you can find some old boards with the same size SMDs, practice removing some components, cleaning the pads and then soldering on some of your new ones. The object is to use enough heat to get the job done quickly and then get out before overheating anything and having the pads separate form the board or ruin the component. Good lighting and magnification is a must for a professional looking job.

author: Monkeh
author_rank: Super Contributor
timestamp: February 10, 2017, 04:29:25 am
content: Quote from: Gregg on February 10, 2017, 04:28:12 amJust bear in mind he works with QFNs, BGAs, and power MOSFET packages - different beasts to SOIC. I've only ever seen him approach one of those, and he didn't actually know how to cope with something so huge!

author: LaurentR
author_rank: Frequent Contributor
timestamp: February 10, 2017, 07:23:51 am
content: To the OP, I am self-taught as far as soldering (a lot of watching YouTube and reading this forum), recently made the jump to trying SMD.I bought myself a few Chinese SMD soldering kits to practice ($2 each on EBay), like this one:http://www.ebay.com/itm/SMD-Components-Solder-Practice-Plate-for-Training-DIY-Module-Electronic-Kit-/281916872729These includes down to 0603 passives and PQFP44 in 0.8mm pitch. After fumbling enough and realizing how critical FLUX is to this whole thing, I found that these component sizes are pretty straightforward to solder. It takes a bit more fine motor control than through-hole and (for my old eyes) some minor optical aids (Optivisor 1.5x for soldering and 3x for inspection), but that's it.Once you've put enough flux on and you've tacked the component into position, you've done the hardest and pitch almost doesn't matter, the solder will flow and do its thing.There are many ways to apply flux (on top of the leads, on the board, with a pen, a syringe, a pointy object...) and to apply solder (drag with a hoof, one pin at a time with a fine tip, multiple pins at a time with a wide tip, solder on pins and drag iron, overapply and use wick...), not counting solder paste methods and they can all work well. You just need to practice and find one you are comfortable with.So no need to worry. A bit of practice to understand how it works and you're good to go.

author: BBBbbb
author_rank: Unknown
timestamp: February 10, 2017, 08:37:35 am
content: Quote from: LaurentR on February 10, 2017, 07:23:51 amThose boards are great for practice, there are a few versions out there. Like you, I did the same thing YT + kits from eBay, and in the end I was surprised hos easy it is, and it seems faster than TH. Once you get the feel for the drag and amount of solder and flux it's done in not time.I'm shortsighted and I didn't need any magnification for the soldering, just used it for inspection.In talks with people who have been doing SMD for some time, no one told me he uses the paste as a preferred method (only if it is a must).

author: Ian.M
author_rank: Super Contributor
timestamp: February 10, 2017, 08:53:16 am
content: For construction with visibly leaded SMD packages (no hidden pads), or if you don't have to change anything larger than a SO-8 you can get by with a good temperature controlled iron, provided there is enough clearance to get the bit to the joint. Once you've got the first corner tacked, ICs in larger packages are actually easier than small passives or transistors.However if you ever have to change a TQFP-68 without a hot air station and preferably a board preheater, you'll be cursing and swearing . . . .If you have absolutely no other option, get someChipQuik, but its not cheap so if you find you are getting the kit out of the draw more than a few times a year you'd be better off getting a cheap hot air station.

author: electrolust
author_rank: Unknown
timestamp: February 10, 2017, 09:04:21 am
content: SOIC is pretty trivial. Make sure you design the PCB with enough pad size for hand soldering. Cuz even SOIC can start to become a challenge if you use IPC7351 "least" size pads. Use leaded solder.

author: mrpackethead
author_rank: Super Contributor
timestamp: February 10, 2017, 09:20:00 am
content: Quote from: Ian.M on February 10, 2017, 08:53:16 amIts good stuff, but you have to make sure you get it all off the board when you clean up..

author: tggzzz
author_rank: Super Contributor
timestamp: February 10, 2017, 09:37:43 am
content: Welcome to the forum. I had similar thoughts to yours a few years ago, and found that SMD isn't difficult; I now prefer it to PTH.I documented my experiences in a number of posts athttps://entertaininghacks.wordpress.com/category/homebrew-pcbs/You will note that you don't need expensive equipment, mainly magnification, solder paste, tweezers, a saucepan, a kitchen gas stove. For desoldering, I'd add a hot air gun and polyimide tape to shield nearby components.

author: RJDog
author_rank: Contributor
timestamp: February 10, 2017, 12:01:37 pm
content: Quote from: tggzzz on February 10, 2017, 09:37:43 amYeah, this seems to be the general consensus, that people find it easy, even preferring SMT after learning... so maybe I should look forward to learning..?Based on the general comments in this thread it does sound like SOIC is a good place to start for me. So my next big question is, should I get every chip I can in an SOIC package, or still use some through-hole chips until I get comfortable with SMT on later projects?

author: jpanhalt
author_rank: Super Contributor
timestamp: February 10, 2017, 12:17:41 pm
content: When I switched to SMT several years ago, I did it in one step: SOIC for chips and 1206 for resistors and capacitors. Either is very easy to solder. Now I use 805's and some of the smaller IC packages, but age does make doing 805 a bit harder. Everything is hand soldered -- no solder paste, reflow, or hot air.John

author: Ian.M
author_rank: Super Contributor
timestamp: February 10, 2017, 12:18:58 pm
content: I'd jump right in and go SOIC, (or TQFP) and mostly SMD for the passives and discretes. Only use through hole if there is a very good reason e.g. stuff that runs hot or is bulky/heavy. If none of the chips are really expensive, then plan on assembling three prototypes - one to learn on where it doesn't really matter if you FUBAR it, then two good ones. Post the PCB layout and schematic here for criticism in the hope of avoiding any major problems or the need for a respin.

author: RJDog
author_rank: Contributor
timestamp: February 10, 2017, 12:40:22 pm
content: Quote from: Ian.M on February 10, 2017, 12:18:58 pmThat's a good idea... I did make the pads on the footprint for the SOIC chips 1mm longer to help with soldering based on suggestions in the videos I watched and reiterated here. Once I get it a little more complete I'll post it here for critique.

author: Ian.M
author_rank: Super Contributor
timestamp: February 10, 2017, 12:47:53 pm
content: Please render it to an image file format (e.g. GIF or PNG - PDF document as an absolutely last resort) as well as your layout package's native file format as not everyone will have the same package installed as you do + its a PITA to have to download Gerbers and open a viewer just to checkout a forum post. Zip the proprietary files + any Gerbers.

author: Watth
author_rank: Frequent Contributor
timestamp: February 10, 2017, 12:51:30 pm
content: Quote from: ebclr on February 10, 2017, 04:03:33 am

author: Ian.M
author_rank: Super Contributor
timestamp: February 10, 2017, 01:03:46 pm
content: Doing good neat hand soldered SMD is *slow* + there's all the flux to clean up. However you can tackle it a bit at a time for a hobby project and get neat results with practice and a steady hand. Avoid *ALL* caffeinated drinks for 24H before your first board . . .As soon as you get into paste, stencils etc. and reflow, you need to be able to complete assembly in one or at the most two preplanned sessions, You cant just pack it up and carry on the next day. Yes, if the pads are correctly sized the parts will to a great extent self align, and there will be less flux to clean up and more even fillets, so its easier to get a neat board, but you cant afford to have anyone jog your elbow or you'll have an unholy mess that's best resolved by starting over.

author: rstofer
author_rank: Super Contributor
timestamp: February 10, 2017, 03:17:21 pm
content: How big is the board? I use a lot of Express PCB Miniboards and they are 2.5"x3.8" As a result, the entire board will fit on the heated surface of a common hot plate. So, put some solder paste on the pads, place the parts and turn the plate on high. Wait until the solder flows and carefully remove the board, setting it aside. Don't jiggle the parts! Turn off the hot plate and you're done.http://www.howardelectronics.com/soldering/soldering-accessories/solder-paste-and-flux/qualitek/p615d-013-8840i-qi-qualitek-sn63-37-solder-paste/http://www.howardelectronics.com/smd-rework/chip-quik-low-temp-smd-rework/smd291/chip-quik-smd291-chip-quik-flux/I use a GE hot plate and there is a void area in the center of the plate. It works well enough but I think this may be a better plate:https://www.walmart.com/ip/Aroma-Single-Burner-Portable-Electric-Range-Hot-Plate-AHP-303/5871070I converted a Black & Decker InfraWave Toaster Oven to a reflow oven using this controller:http://www.rocketscream.com/shop/reflow-oven-controller-shield-arduino-compatibleJust gut all the electronics, connect the heaters up to a solid state relay and you're good to go. It is worth the time to fill the wall cavities with high temperature insulation from McMaster-Carr.

author: tkuhmone
author_rank: Regular Contributor
timestamp: February 10, 2017, 04:18:43 pm
content: Quote from: LaurentR on February 10, 2017, 07:23:51 amthanks for link, today I also ordered couple of boards. So I could try soldering with hot air, with flux etc etc.

author: tautech
author_rank: Super Contributor
timestamp: February 10, 2017, 06:49:07 pm
content: Quote from: tkuhmone on February 10, 2017, 04:18:43 pmYou could, I did and reverted to hand soldering small boards.Air takes a very gentle touch and low air speeds and with the component density capable with SMD it's too easy to displace other components adjacent to those you are working on.

author: RJDog
author_rank: Contributor
timestamp: February 11, 2017, 01:59:03 pm
content: I think I'll be trying to hand solder the SOIC chips on the board using traditional methods and save the paste and reflow methods (hot air, reflow oven, etc.) to sometime when I have a little more cash to spend and more patience. Everything I've seen and based on comments here leads me to believe I should be fine mounting the SOICs using a heat adjustable solder iron with a reasonably fine tip and fine grade solder. I'll use SOIC for everything I can get in an SOIC package...Related, not related, what is the etiquitte for posting PCB design for critique? Post a picture of the top copper layer and a separate picture for the bottom copper layer or picture of the combined top/bottom..?

author: Monkeh
author_rank: Super Contributor
timestamp: February 11, 2017, 02:36:27 pm
content: Quote from: RJDog on February 11, 2017, 01:59:03 pmWhichever you like. Most of us are quite used to looking down through PCBs..

author: rstofer
author_rank: Super Contributor
timestamp: February 11, 2017, 04:05:30 pm
content: Quote from: RJDog on February 11, 2017, 01:59:03 pmYou may find that you don't want a 'fine' tip for drag soldering multi-lead SMD components. You can also use solder paste instead of solder wire. Just run a long bead of paste perpendicular to the pins, place the parts and tack opposing corners. Then just drag the tip across the pins. A more conventional technique is to use wire solder and tack the corners as usual. Then put a small dab of solder on the tip and drag it across the pins. This works very well if you run a bead of flux perpendicular to the pins.This is all much ado about nothing. Soldering SMD packages turns out to be pretty easy. SolderWick is pretty handy. Paste flux is the secret and paste solder has a place as well.Where solder paste is really helpful is on 0805 packages and smaller. Place the part in the paste, press down with curved tweezers and hit the joint with the iron. This will prevent tombstoning.Look for videos on 'drag soldering'.

author: jpanhalt
author_rank: Super Contributor
timestamp: February 11, 2017, 04:07:24 pm
content: Quote from: RJDog on February 11, 2017, 01:59:03 pmHere are couple of hints for starting out:1) A very tiny dab of rosin flux under the device will help hold it.2) For resistors and caps, use a microdot of CA (crazy glue, cyanoacrylic) on the board between the pads. When you put chips down, you will have a little time to get it adjusted, then it is quite robust to soldering. You can put a lot of chips in place, then methodically solder them. The nice thing about CA is that it is heat sensitive. At soldering temp, most of it will just vaporize (it is made by distillation of the polymer). Try to avoid getting it on the pad. As for the "microdot", I use a thin piece of music wire ground to a dull point. Place an ordinary drop of CA on bare copper PCB. The bare copper will not set it off for quite awhile. I dip the music wire applicator into the puddle, then touch to the board. You will be applying <0.1 microliter (i.e., a small fraction of a milligram).3) The CA method doesn't work as well for SOIC chips, as there is often a small gap under the IC; however, medium CA will work. Generally, SOIC's are so easy to solder, I don't bother.4) As an alternative to #2, I will put a thin tiny dot of solder on one pad. Place the component, then heat the pad and it will float into place. The little wire I made for #2 can be used to position the component and/or press it down. If you get too much solder, just use solder wick to remove it. You don't need much more than a plating thickness. Once one end is tacked down, then solder the other end. Finally make a good solder joint on the tacked end.The CA method is, of course, what is done in industry on occasion. I simply found that hobby CA works pretty good compared the the expensive branded stuff. I use method #2 when I have a lot of chips to solder and #4 when just a few.Apologies, if this comment repeats comments from below. I sort of lost tract after my first post. I also have my usual two cups of coffee in the morning.John

author: james_s
author_rank: Super Contributor
timestamp: February 11, 2017, 07:17:15 pm
content: IMO soldering surface mount parts is easier than soldering through-hole parts for the most part, I don't know why people are so scared of them. With SMT there is no trying to wedge the part in there while you flip the board over and solder, no trimming the excess bits off, no issues with solder wicking up through plated through holes, it's just a lot cleaner. Also I can reflow solder a whole board all at once on my hotplate but that isn't really necessary. After working with quite a few 0.5mm pitch QFPs the SOIC chips feel like big chunky things, you could solder those with one of those big old Weller soldering guns. Just tin one of the corner pads with a bit of solder, then place the part there and reflow that pin, adjusting the IC as necessary until it's centered. Then solder the other pins just like you'd solder anything, take care not to use too much solder. The same technique works for chip resistors and capacitors, just don't use too much heat or you'll melt the solder on the end you already did when you solder the other end.My favorite trick for hand soldering high density QFP stuff is to use lots of flux and put a bit of solder on the face of a wedge tip on the iron and then touch and drag away from the IC. If you get too much solder and it bridges, add a bit more flux and drag it off, wiping the iron on the cleaner between drags. If there's way too much, a bit of solder wick will remove it.Don't fear SMT, it's really not hard. Practice soldering some cheap parts on a scrap board and you'll get the hang of it, then you'll wonder why you waited so long to try.

author: mrpackethead
author_rank: Super Contributor
timestamp: February 11, 2017, 07:21:10 pm
content: QuoteI'd never ever go down this path. If you want to take the part off you can't! and there is no need to take this path either.

author: tautech
author_rank: Super Contributor
timestamp: February 11, 2017, 07:34:53 pm
content: Quote from: RJDog on February 11, 2017, 01:59:03 pmIf you've done PCB design most of the traps for young players will be self explanatory except when it comes to rework and the tools you might use/have for such, probably moreso for prototyping.If you want us to have a good look, top and bottom please.

author: jpanhalt
author_rank: Super Contributor
timestamp: February 11, 2017, 08:17:27 pm
content: Quote from: mrpackethead on February 11, 2017, 07:21:10 pmYou missed the point about the temperature sensitivity of CA. Most of it is vaporized once the part is soldered. The glass transition temperature of common household/hobby versions is less than 100°C. More specialized versions have higher Tg's, but clearly my discussion did not relate to them.Edit: Sorry, I was in a hurry and forgot to address your second point. If there is no need for it, then why do manufacturers still do it? Why is there a "glue" layer? Ever see the little red (color doesn't matter) spots under various SMD's?John

author: eugenenine
author_rank: Frequent Contributor
timestamp: February 11, 2017, 08:40:36 pm
content: CA smells really good when soldering too

author: mrpackethead
author_rank: Super Contributor
timestamp: February 11, 2017, 11:34:03 pm
content: Quote from: jpanhalt on February 11, 2017, 08:17:27 pmNot for the reason you think they do. Its to enable double sided placement for parts that wont' say put due to surface tension when the other side is reflowed. Ever notice that the glue is only on one side of the pcb

author: tooki
author_rank: Super Contributor
timestamp: February 12, 2017, 10:06:41 am
content: Quote from: mrpackethead on February 11, 2017, 11:34:03 pmAnd for SMD on wave-soldered boards.

author: tkuhmone
author_rank: Regular Contributor
timestamp: March 14, 2017, 03:13:43 pm
content: Quote from: LaurentR on February 10, 2017, 07:23:51 amcould I ask how much did it took time for the PCB set to deliver ? I have wait mine for a bit over one month now, tracking did only show "Shipping info received". Not any tracking details visible, like packet locations...EDIT: I also bought the angled weller PT-series tips (for drag solder practise). Got them new for fairly good price, two tips cost 0.8€ (without VAT)

author: LaurentR
author_rank: Frequent Contributor
timestamp: March 14, 2017, 04:54:15 pm
content: Quote from: tkuhmone on March 14, 2017, 03:13:43 pmI don't think I have used this particular vendor, but he's got good feedback. ePacket from China is 2-3 weeks to the US, but there is a very long tail. I had one over xmas that took 2 months, mostly stuck in China.If it says "shipping info received" and not "Acceptance..." or "Processed through facility" in China, there is an issue right at the start. Contact your seller.

author: TheDane
author_rank: Regular Contributor
timestamp: March 14, 2017, 06:07:01 pm
content: Microscope. Microscope........ (Optical Stereo is best, USB Digital the worst)If you can't see what you've soldered, are you willing to risk your work by powering it?- or check for shorts with your huuuuuge multimeter probes, and then creating small shorts whiule doing so..... (pushing the solder to the sides, it's sooo easy to do on 0.4 and 0.5 pitch devices if not extremely careful)Practice (on a scrappy lot) before doing high-cost devices, and get used to the difference in hand-eye body action department.And yes, it's a LOT easier to rework a simple mistake than replacing the power supply, the device you tried to solder, and all the thin copper traces that acted as a fuse. It might not be as fast initially due to the extra tenderness, but in the long run it will save you time if you do it 'enough' - it does for me anyway, and I repair stuff for a livingSo lastly from me - Practice, and various forms of feedback - -get's it done right.- don't try to save time or cost, at least if you want quality

author: james_s
author_rank: Super Contributor
timestamp: March 14, 2017, 06:48:20 pm
content: I use an inexpensive illuminated loupe to inspect soldering on fine pitch stuff. A 3D microscope is an expensive piece of gear for most hobbyists, I don't need one enough to justify the cost.

author: TheDane
author_rank: Regular Contributor
timestamp: March 14, 2017, 07:29:22 pm
content: Yeah.Tools. Tools, Tools tools.... Me - I either love them, or need them and have a love-hate relationship.I love my Metcal soldering station, and I would never go back to my Well-hellish iron without a fight.It's hot faster, it delivers more heat and I could go on. Yes, it's pricy - but worth itI have an Andonstar V160 2MP USB Digital Microscope at home, it does the job - but it lags and details can be hard to see.It's not great, and I really miss the microscope I have at my workplace. If just the price was right......- but at home I have more time, and I guess it's true: Time is money

author: ebastler
author_rank: Super Contributor
timestamp: March 14, 2017, 08:15:17 pm
content: Quote from: tkuhmone on February 10, 2017, 04:18:43 pmPlease don't bother with solder paste stencils and hot air, hot plates or whatever for now!Throughout this whole thread, ebclr has been the only one suggesting that approach, and several users have already contradicted him.Hand soldering is the way to go for SOICs and smallish PCBs. You will not even need extra flux for 1.27mm pitch pins; the resin core in the solder is perfectly fine. Just make sure that to use sufficiently thin solder: 0.5mm diameter is fine; thicker stuff makes it more difficult to dose it right.Even 0.5mm pitch can be hand-soldered nicely, but then the technique becomes a different one, and youwillneed to add extra flux to make sure the solder ends up where you want it to go. Others have suggested youtube channels to watch which do a great job demonstrating these advanced techniques -- but that's for later...Have fun with your SOIC-based layout -- and yes, I would suggest to use SOIC parts throughout. For practice, because it looks nice and consistent, and because you will enjoy the soldering!

author: mrpackethead
author_rank: Super Contributor
timestamp: March 14, 2017, 08:24:54 pm
content: Quote from: ebastler on March 14, 2017, 08:15:17 pmA stencil, paste and some way to reflow is a very valid option. Its not the only option but it a valid one.

author: ebastler
author_rank: Super Contributor
timestamp: March 14, 2017, 08:31:46 pm
content: Quote from: mrpackethead on March 14, 2017, 08:24:54 pmSure. Obviously reflow soldering has its place, and at some point (pitch) it even becomes the only alternative.But for a beginner in SMD, who owns and knows how to use a soldering iron, and wants to get first experience using SOICs? Why bother buying new equipment and materials, getting a stencil made, and familiarizing yourself with an entirely new process? That creates an unnecessary hurdle, and I strongly advise against it.

author: tkuhmone
author_rank: Regular Contributor
timestamp: March 14, 2017, 09:18:48 pm
content: Quote from: ebastler on March 14, 2017, 08:15:17 pmI plan to go ahead with simple setup first... And also with the equipment I currently own. I do have already 0.5mm SnPb solder wire (stannol).In the soldering iron, I have approx 1.5mm wide chisel tip - that should be ok soldering practises now (for typical 0805 size).I do not currently own hot air soldering equipment, for the moment that is not on my list to purchase.I have an access to optical stereo microscope with sturdy base platform . The column used to adjust eyepiece height, that is around 50..60mm diameter and feels very solid. If correctly remember there is approx 20cm of work space between base platform and objective lens. That could be very useful equipment later on :-)

author: mrpackethead
author_rank: Super Contributor
timestamp: March 14, 2017, 09:49:29 pm
content: Quote from: ebastler on March 14, 2017, 08:31:46 pmAnd as someone whos done a lot of SMD, i'd say its well worth the effort to tool up with some new gear, and learn the new process.. Because its a skill that is *well* worth learning.. Just as much as learning to hand solder SMD parts.

author: james_s
author_rank: Super Contributor
timestamp: March 14, 2017, 09:55:42 pm
content: I do reflow and have used stencils a couple times but sometimes I just hand solder. Not worth the expense of a stencil until you are positive that your layout is good, so I always at least build one prototype by hand or if I reflow then apply solder paste with a toothpick.

author: LaurentR
author_rank: Frequent Contributor
timestamp: March 14, 2017, 10:00:04 pm
content: You _will_ need manification, at the very least to inspect. If you have good, young eyes, soldering should be possible without magnification in many cases.I personally use a couple of Optivisors, one at 1.5x with good working distance and enough magnification to be able to solder most everything, and one at 2.75x with much shorter working distance but enough magnification for inspection. Needs strong lighting too.https://smile.amazon.com/Donegan-OptiVisor-Headband-Magnifier-Magnification/dp/B0068OSIIS/I use my wife's microscope on rare occasions. The visors are much friendlier to use for occasional soldering/inspection. If you are going to spend hours doing boards, a microscope is a much better (and much more expensive) option. You can work with the Optivisors for hours, but if you need large magnification, the small working distance becomes a liability and you need fancier optics than a single lens to move your head away from your hands.

author: james_s
author_rank: Super Contributor
timestamp: March 14, 2017, 10:08:25 pm
content: Most stuff I just inspect visually without magnification. The 0.5mm pitch ICs I use an inexpensive illuminated loupe, it works fine. I can just about do it without a magnifier but it's easy to miss a bridge that way.

author: mrpackethead
author_rank: Super Contributor
timestamp: March 14, 2017, 11:49:43 pm
content: Quote from: james_s on March 14, 2017, 09:55:42 pmAt least for me the cost of a stencil is much lower than the cost of the time it takes to place the parts by hand and then hand solder.. An unframed stainless stencil for a small pcb starts at just $10.

author: Rick Law
author_rank: Super Contributor
timestamp: March 15, 2017, 03:08:35 am
content: Quote from: RJDog on February 10, 2017, 03:39:20 amRJDog,I understand the uneasy you are feeling. I am a merely an inexperienced hobbyist and I felt the same when I considered stepping into SMD soldering. The tasksjust appeared to beso damn impossible.Your questions and reluctance are so similar to my questions and reluctance then. So, allow me to share the story of my venture into SMD... Hopefully, it will help you kick start your venture.I kicked around the idea of dipping into SMD soldering for what seemed like ages. I watched a few SMD soldering videos and kicked around it some more ever so reluctant because it looked so hard. I found one of my old dead cell phone (StarTac) and started removing parts, and putting them back, and removing them, and putting them back... Did that for may be a couple of weeks (dozen or so 1/2 hour workout), may be more. But the phone was dead before I start, so I never knew if the replacement was correct or if I cooked the part and didn't even know. I did "solder" one IC for so long the pin felt out. So I kick around the idea a while longer.I have a couple of SMD's I managed to send to electrocution. I need to replace them but they were 1mm pitch and 0.5mm pitch . It look damn near impossible to me.Finally, I decided to have a go. Dig out that cell phone again, this time, I practice the work flow to cut down the solder-iron contact time. I recall I set a 2 seconds (per pin) target and 5 seconds limit.After another hour or two of practice, the next day, I decided - time to have a go!What I was glad I had at hand:- good flux- good solder sucking braid (when I applied too much)- a couple of magnifying glass (4x and 10x loupe)- a small screw driver (to help position and to hold the part)- 1mm solder (would have prefer smaller, but that's what I got)Nothing fancy, I think you probably have everything I had in that list.The technique I was most glad I learned (from the videos) before I start:- flux well- start with a corner pin (so it hold in position), then inspect carefully, then opposite corner, then inspect carefully again, then the rest of the pins, then inspect carefully again.First shot, 0.5mm pitch (10 pins) VSSOP. Got it on, it works! Second shot, 1mm pitch (6 pins) SOT23-6, got it on, it works. Two successes in the space of an hour or so. I was so pleased by it I wrote this:https://www.eevblog.com/forum/beginners/some-times-things-work-out-the-way-they-should/It was beginner's luck. As beginner, I was extra careful. After that first day, SMD doesn't scare me anymore. It doesn't look so impossible any more. I have since improved - now SMD is just another chip to me.Put your doubts in a jar, screw the lid shut and keep your doubts in that jar; then, with your doubts contained, have a go at it. Practice some, practice some more, then start with some cheap IC's... (I started with the ADS1115 which was a $6 chip if I recall... it worked out well but it was not smart.)Good luck!By the way, luck tends to favor the well prepared...

author: james_s
author_rank: Super Contributor
timestamp: March 15, 2017, 04:38:02 am
content: Quote from: mrpackethead on March 14, 2017, 11:49:43 pmCheapest I found was $20 by the time I paid shipping. It did save some time when I built several identical boards but I still had to place the parts one at a time and that was a longer part of the process than dabbing solder paste on the pads with a toothpick.SOIC though, one could hand solder those with one of those comically huge soldering irons used for stained glass or a Weller soldering gun if that's all they had. The solder joints are not that much smaller than for a DIP.

author: ebastler
author_rank: Super Contributor
timestamp: March 15, 2017, 05:42:51 am
content: Quote from: mrpackethead on March 14, 2017, 09:49:29 pmJeez, yes -- we are on the same page here. But I recommended not to bother with reflow soldering "for now", i.e. for a new user soldering his very first SMD (SOIC) parts.If you go back to the third post in this thread, one "mrpackethead" puts ebclr's unconditional recommendation for reflow into perspective, and points to a very nice hand-soldering tutorial video...

author: mrpackethead
author_rank: Super Contributor
timestamp: March 15, 2017, 09:39:23 am
content: Quote from: ebastler on March 15, 2017, 05:42:51 amAnd i recommend that it is well worth the effort to 'bother'.

author: ebastler
author_rank: Super Contributor
timestamp: March 15, 2017, 10:24:35 am
content: Quote from: mrpackethead on March 15, 2017, 09:39:23 amBut can we agree that you don't need to (and probably should not) transition to reflow soldering before you solder your first SMD parts ever? Pretty please?

author: tautech
author_rank: Super Contributor
timestamp: March 15, 2017, 10:28:28 am
content: Quote from: ebastler on March 15, 2017, 10:24:35 amOf course not, I quite agree....forget an iron altogether and go vapor phase.If only newbies knew what it was.

author: tggzzz
author_rank: Super Contributor
timestamp: March 15, 2017, 10:35:57 am
content: Quote from: ebastler on March 15, 2017, 05:42:51 amI think it is worth learning reflow soldering very soon, even for small boards. The results are fast, easy and surprisingly good; to my surprise I now prefer SMD. The capital cost is minimal: solder paste and a £5 saucepan, and preferably a non-contact "point and shoot" thermometer. See my .sig for my tools and techniques.For old excellent soldering videos, seehttps://www.youtube.com/playlist?list=PL926EC0F1F93C1837The last one is about "flatpack" ICs.

author: tooki
author_rank: Super Contributor
timestamp: March 15, 2017, 11:23:49 am
content: Reflow for SMD is awesome; way easier than using an iron. The $60 for a cheap 858 hot air unit are worth every cent.

author: mrpackethead
author_rank: Super Contributor
timestamp: March 15, 2017, 06:58:59 pm
content: Quote from: ebastler on March 15, 2017, 10:24:35 amYou don't need to do anything. But if you want to learn about the soldering method that SMD parts where designed for its a good idea.

author: ebastler
author_rank: Super Contributor
timestamp: March 15, 2017, 07:29:01 pm
content: "packethead" is another word for "blockhead" in English, isn't it?(Sorry, not a native speaker... But I don't think I was expressing myself in such an unclear manner. Reflow is great, but not for your first SMD part. Bye now.)

author: mrpackethead
author_rank: Super Contributor
timestamp: March 15, 2017, 08:07:24 pm
content: Quote from: ebastler on March 15, 2017, 07:29:01 pmNo its not. Its a reference to the fact that at one stage in my life i was the lead architect in a team building networks. head of packets?reflow is one method. Hand Soldering is another. Having spent considerable time as a volunteer teachign electronics assmebly at the local maker space, i'll tell you that the folks to do their first SMD work with a stencil, paste and a low cost toaster actually get something useful working in the space of one evening.Hand soldering SMD is a skill that takes much more time to develop. But it is a skill that is very helpful and esssential when you are developing electronics..

author: james_s
author_rank: Super Contributor
timestamp: March 15, 2017, 09:58:55 pm
content: I think there's value in both. If one is not in too much of a rush, I would suggest learning to hand solder it first, then when you build something with a stencil and reflow (or more often in my case a toothpick and reflow) it seems very easy.It's the same as when I was learning to bend neon tubing a number of years ago, which is much, *much* harder than it looks, practice with the big 14mm stuff and then when you try bending 10-12mm tube it seems so easy.

author: tkuhmone
author_rank: Regular Contributor
timestamp: March 17, 2017, 07:48:50 pm
content: Quote from: tkuhmone on February 10, 2017, 04:18:43 pmset of PCB's arrived today, five boards totally. Some work for the soldering iron :-) Single sided boards and material propably is FR-2.

author: TheDane
author_rank: Regular Contributor
timestamp: March 17, 2017, 08:21:52 pm
content: I have worked with stencils, and I would only recommend a stencil while doing a project. A bare PCB, which then gets populated and soldered. One PCB by one another.The soldering iron is for touching up, very few and larger components, and/or doing through hole pin stuff.A syringe with fresh/good paste and a decent needle can make a pretty line of solder paste, which I find easier to apply rather than fitting a stencil onto an already populated board I'm doing a repair on, smearing paste while holding it flat. It takes me longer, and a possible larger clean up job afterwards is lurking underneath the stencil.Excess solder I remove with the tip of my tweezers, under a stereo microscope. This works wonders fixing various iPhone internal connectors, and they're not big. The right amount on each pin, the component on top - heat. The solder between the pins flow to the pin, a perfect result. A standard SOIC is easy, when practice is done - know the trick's, learn and build/make your own new better tricks. ShareOlder paste can be used in a pinch, I have found - the trick is to mix a larger portion of the tired paste well getting it wet/flowing, and then making sure the receiving PCB pads have been completely wetted. Works best with the larger sized stuff, though, but 0201's still solder ok.

author: tkuhmone
author_rank: Regular Contributor
timestamp: March 19, 2017, 08:39:58 pm
content: Quote from: tkuhmone on March 17, 2017, 07:48:50 pmHere is attached images of the board. Kit containing of:Main PCB, single sidedtwo 16pin SOICtwo 44pin QFPseveral 0805/0603 resistors & capacitorsMELF (MostEnd upLying on theFloor) diodestransistors, SOT-230603 resistor arrays

author: tkuhmone
author_rank: Regular Contributor
timestamp: April 09, 2017, 03:36:22 pm
content: Quote from: tkuhmone on March 14, 2017, 09:18:48 pmI took a quick test of the stereo microscope and the optical & mechanical quality looks very good, it offers zoomed view also (Wild M3Z). I need to get practise with eyes-hands-soldering iron combination :-)

author: Vtile
author_rank: Super Contributor
timestamp: April 09, 2017, 04:42:18 pm
content: Without purposedly build PCB .. not a joy. I have done it to certain extend in veroboards and similars, but the SOIC (1/20th of inch spacing) and other multilegged parts are just pita to handle with prototyping methods. The best so far is the coilwire (PU coated [better than AWG30 solids what I have tested]) where you can not fit the part to PCB blobs directly.For flux I use some homebrewed rosin flux (ecoRosin^tm & IPA), which I don't care to soak (clean) away. Depend on the circuit component ofcourse if it makes a difference.I hop in to the SMD/SMT area when I can buy 3rd hand manufacturing line for pennies.

author: Zero999
author_rank: Super Contributor
timestamp: April 09, 2017, 07:46:49 pm
content: Quote from: ebastler on March 14, 2017, 08:15:17 pmI agree. I've noticed some people recommend extra flux but I find it counter productive. All it does is create more smoke and mess. The only time I've ever had to use extra flux is when the board or components are badly oxidised.

author: Vtile
author_rank: Super Contributor
timestamp: April 10, 2017, 09:45:26 am
content: Quote from: Hero999 on April 09, 2017, 07:46:49 pmIt might have something to do with the solder used. If it is far from optimum the extra flux might help it to flow. "Dry" solder tend to be "sticky" and mainly forming a globs. This is my experience soldering with far from decent equipment and with old chinese mystery solder (it were cheap 15 years ago when I got the big spool with my hobby pennies)

author: electrolust
author_rank: Unknown
timestamp: April 14, 2017, 12:31:18 am
content: Quote from: TheDane on March 14, 2017, 06:07:01 pmAny particular product recommendation? I've been using a visor/headset glasses but these are limited to about 3.5X magnification and I would like more.https://www.adafruit.com/product/1345is interesting, and with TV output I guess the response time is instantaneous but there's still the problem of it being 2D.

author: TheDane
author_rank: Regular Contributor
timestamp: April 14, 2017, 08:21:09 pm
content: Quote from: electrolust on April 14, 2017, 12:31:18 amOh boy. Not by name/brand - sorry.What I have found to be great is a base which has the right height, so you can work comfortably under the microscope without tiring your hands, arms, fingers, shoulders, etc.Naturally aheavy sturdy constructionthat doesn't tip, a base working area that suit your needs and dials that move without slack etc.The 3D view is excellent as it minimizes guesswork on where the tip actually is, minimizing burned/marked adjacent components when placed really close to what is being worked on. There's no delay in visuals, so work pace can be sped up considerably.I tried to google 'stereo microscope' and then do the pictures view. There's tons of different layouts. Some might work great for you, and not for me - I have worked with a few different types, and typically you get what you pay for quality wise.Most common difference is viewing angle - some are directly down, I don't like those. I prefer those you 'look into'.I recommend a microscope with a zoom level starting as low as possible - I find that when working with larger components and a magnification of just 4-5 - there's no room in the viewing area, and I have to move things around. 40x magnification is enough to do 01005 components, and still getting good views - if the lighting is good enough. LED rings are not great imho, the light from a halogen bulb is much better for identifying colors and contours like tracks, solder mask, bare board, component cracks, etc.- and possibly getting a local one, as shipping glass mounted lenses can (if knocked around too much) cause problems.Good luck, and they do start somewhat cheap - depending on model and features. Buyer beware, try it out if possible before purchase.PS - I have no experience with the mantis-type

author: bson
author_rank: Unknown
timestamp: April 15, 2017, 09:23:12 pm
content: Quote from: electrolust on April 14, 2017, 12:31:18 amThe cheapest Amscope with 2.5X/5X magnification and boom mounted (so you can swing it out over your work area), with the cheapest CFL ring light. Directional lights cast shadows, and at such low magnification lighting isn't a big issue.This will work nicely:http://www.amscope.com/microscopes/10x-30x-stereo-microscope-on-single-arm-boom-with-ring-light.htmladd a 0.3X barlow lens - this will reduce the magnification to 3.3X/10X, widen the field, brighten the view, and triple the working distance (to 300mm at 3.3X). The light will be a tad dark at 10X but that's a really high magnification for this sort of use and more for close inspection for things like solder crack lines. I have an older trinocular version of this (2.5X/5X), and trust me - there's very little to be gained from spending more on something better. (http://www.amscope.com/accessories/barlow-lens/0-3x-super-widefield-barlow-lens-for-sm-series-stereo-microscopes-48mm.html;there's also a 0.5X but that would probably yield excess magnification.) Trinocular if you want a dedicated camera attachment, but frankly unless you are seriously into shooting videos or do classroom instruction, don't bother. I have a trinocular head Ineveruse and in my mind the most expensive tools are those that never get used, no matter how little I paid for them.The other alternative is to hunt on eBay for a nicely priced used Zeiss, Leica, Nikon, Minolta, etc. I do strongly recommend low magnification and a boom mount though; even if the glass is superior a dissection type scope will be far less convenient (and at such low magnifications even the Amscope optics are perfectly good).