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Soldering with a Toaster Oven 252

Posted by CowboyNeal
from the easy-bake-electronics dept.
nullset sent in a link to the Seattle Robotics Society about soldering in an unconventional way. Instead of the traditional soldering iron, Kenneth Maxon has successfully used a toaster oven to solder surface mount parts. The "magic ingredient" that facilitates this is a water-soluble solder paste. I wish I'd thought of this back when I had to solder one of those *ahem* aftermarket accessories to my playstation, since the whole process looks easier than trying to hold a soldering iron steady.
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Soldering with a Toaster Oven

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  • Ding! (Score:4, Funny)

    by B3ryllium (571199) on Thursday March 27, 2003 @04:51PM (#5610099) Homepage
    Your motherboard has finished. Don't forget to ground it properly!
  • Pentium motherboard in Pentium 4 motherboard out.

    Seems simple enough, where can I buy one?
  • What isnt a toaster good for?
    (I regretfully ask)
  • Some already use solder paste when fitting mod chips to consoles. You can dip the wire into it and give it a quick blast of heat while pressing the wire against the connection point.
  • by Lumpy (12016) on Thursday March 27, 2003 @04:54PM (#5610137) Homepage
    soldering in an unconventional way

    sorry but industry has been doing the solderpaste->heated oven dance for years now.

    it's unconventional to use a hand held iron unless you are doing board rework.
    • by frohike (32045) <bard.allusion@net> on Thursday March 27, 2003 @05:28PM (#5610361) Homepage
      Yes, I agree. When I first came to my current day job back in about '98, they had a little toaster oven they used for the completion of SMT boards. I think now they just send the boards out to be produced and populated elsewhere (it's cheaper that way once you reach a certain point) but they were most definitely doing it for a long while before that.

      How do you guys think Ball Grid Array packages are mounted on a board? :) These are the chips (like embedded PPC) that just have a big matrix of solder balls on the bottom which are soldered to the board.

      Which reminds me of this humorous episode where a guy pulled down the oven from the shelf and cooked his lunch in it, not knowing what it was... and when we learned what had happened we all just about shit a brick. He didn't get lead poisoning or anything though.
    • I think it was a pun on conventional :P

      Being a conventional oven

      Opposed to a convectional oven.

      Which is which, I dunno...thats womans work!
  • by heXXXen (566121) <(moc.reppohcp) (ta) (ffilc)> on Thursday March 27, 2003 @04:55PM (#5610147)
    Mirror here. [hexxxen.net] don't be surprised if all the images aren't on it yet...getting 900bytes/sec here folks.
  • Solder Paste!? (Score:3, Interesting)

    by SHEENmaster (581283) <travis@uRASPtk.edu minus berry> on Thursday March 27, 2003 @04:56PM (#5610155) Homepage Journal
    First we had solid solder, cool. Then we had rosin-core solder for electronics, cooler. Then we had tabs of solder that could be melted with a lighter, lame. Now we have a toaster that can be used to solder, which is theoreticaly cool but realistically lame.

    Wouldn't this paste have a higher resistance than the solder we know and love? Couln't a soldering iron be used to heat it with greater efficiency? Does it have any use outside of SMD?

    Maybe I'm just weird, but I won't part with my soldering iron any time soon. SMD may be cool, but it doesn't have the "cobbled togethor" look of a traditionally etched and soldered circuit.
    • Re:Solder Paste!? (Score:3, Informative)

      by Hayzeus (596826)
      You're not weird, but sometimes you have no choice. Some chips just aren't available in DIP form, especially a lot of the kool robotics stuff like the ADXL acceleration sensors, a slew of microprocessors, and so on.

      This page has actually been around for a while. It's seems a pretty good idea, though I've never tried it.

    • Re:Solder Paste!? (Score:4, Insightful)

      by barawn (25691) on Thursday March 27, 2003 @05:24PM (#5610333) Homepage
      Wouldn't this paste have a higher resistance than the solder we know and love? Couln't a soldering iron be used to heat it with greater efficiency? Does it have any use outside of SMD?

      No, it wouldn't have a higher resistance, at least not significantly more (or less). It's still just basically solder.

      As for uses outside of SMD - no, not really. Traditional rosin-core, or whatever else floats your boat, is best for through-hole.

      However, through hole is a pain in the butt. It's also impossible to use throughhole for more advanced circuits. Through-hole is a dying technology. It's terrible noise-performance wise, space wise, and in solderability. SMD is terrific - you just need to get used to it.

      It also takes a fraction of the time to solder this way, and (done properly) reflow has the distinct advantage that an idiot can do it. The parts will simply wick to their proper locations. It's (mostly) foolproof. Plus (if you're careful) you won't damage components because you're not heating them with several-hundred-degree heat like a soldering iron does.
      • "Plus (if you're careful) you won't damage components because you're not heating them with several-hundred-degree heat like a soldering iron does."

        Yeah but where's the CHALLENGE? That just takes all the fun out of garage tinkering, trying to solder components onto perfboards without burning up a) the components and b) your fingers.

        SMD may be the future, but it's for weenies...

        • The challenge is in coming up with a design that works, and then trying to actually install everything correctly with equipment that's not good enough for what you're doing.

          The amazing thing about SMD is all that you can do with it, and ESPECIALLY if people get good at using common items like a toaster oven. Then it becomes feasible for people to "garage tinker" up an entire computer.

          Which is not out of the question.

          Especially when you can get simple PC boards for something like $20 - in quantities of 1.
      • Re:Solder Paste!? (Score:3, Informative)

        by klui (457783)
        I've seen a professional at Cisco install SMD CPUs that consisted of several hundreds of pins in around 30 seconds.

        There is some prep work, among which are cleaning the board/pads with some sort of solution (I was told alcohol) and the use of what appears to be a microprocessor-controlled iron with a flat tip (looks like an L, the long end of it is used like a spatula). Cannot recall the type of solder, but it's in the form of a paste that's easily applied.

        She started by soldering two pins on opposite cor
  • by RalphBNumbers (655475) on Thursday March 27, 2003 @04:57PM (#5610167)
    I'm thinking that's what makes this work.

    I wonder if this could be adapted for mass production? Not having to individually solder pins would have to speed things up. The error rate is a little high for production, but I'm sure it could be improved with a little engineering.
  • Isn't this the same place we read about the person who put his PDA in the oven to dry it?

    Solder melts at around 350 degrees, the maximum storage temperature for ICs is around 140 degrees F, and 200 for mil spec chips. Heating the whole board and components to 350 for long enough for the solder to melt will destroy the chips.

    Jason
    ProfQuotes [profquotes.com]
    • by nullset (39850) on Thursday March 27, 2003 @05:00PM (#5610192)
      Read the "cooking" times mentioned on the page....the magic is in the solder paste that melts much more quickly than standard solder.... simply sticking a board into a toaster oven with normal solder definitely WOULD NOT work :)

      --buddy
    • Solder melts at around 350 degrees, the maximum storage temperature for ICs is around 140 degrees F, and 200 for mil spec chips. Heating the whole board and components to 350 for long enough for the solder to melt will destroy the chips.

      Wow you know absolutely nothing about electronics.

      everything you own that has surface mount electronics in it has gone through this process. Either Via an Oven or using superheated air or finally Infared light for heat. (Yes, I have used an IR rework station to get a BGA
  • by Valiss (463641)
    So does this mean that if I use this process for my MB and put a notoriously hot AMD chip in it, it'll re-melt the paste?

    "No, seriously guys, my computer is bleeding to death."

  • by _Eric (25017)
    Well, soldering in hovens is by no means an unconventional way. Nowdays components are in BGA packages (ball grid arrays), which are matrices of solder balls under the package ( see image [mrsscrap.com]). Those baybies can be soldered ONLY in an hoven. Same goes to the chipset of the motherboard of the computer you're using right now, unless it's a rather old one. So those guys apply the indutry standard to an amateur project. You can note that the things they solder could also be soldered with a soldering iron. Soldering
  • http://216.239.39.100/search?q=cache:okXVGJjYnsAC: www.seattlerobotics.org/encoder/200006/oven_art.ht m+&hl=en&ie=UTF-8 i know this is redundant but even the cache was slow to load, so here it is
  • by Tekmage (17375) on Thursday March 27, 2003 @05:19PM (#5610293) Homepage
    Why burn ants when you can put that magnifying glass to good use soldering circuits together in the summer sun? ;-)

    Seriously though, wouldn't it be cool if someone modified a laser-pen (or appropriately set up fibre-optic light source) to serve as a soldering iron?

    No more fumbling with hot-metal iron pens. Shutter the light and it's cold!
    • no peeking! (Score:4, Funny)

      by Erris (531066) on Thursday March 27, 2003 @05:56PM (#5610543) Homepage Journal
      Seriously though, wouldn't it be cool if someone modified a laser-pen (or appropriately set up fibre-optic light source) to serve as a soldering iron?

      Yes it would be cool to get watts worth of heat from a milliwatt source.

      No more fumbling with hot-metal iron pens. Shutter the light and it's cold!

      That's true! When your eyes quit steaming, you'll quickly tire of soldering things by sense of touch and smell.

    • Good, leave the ants [antfarm.mac.x] alone. [grin] :)
  • Instead of the traditional soldering iron, Kenneth Maxon has successfully used a toaster oven to solder surface mount parts.

    We.., *I* can solder SMPs with a *blow drier*. Ergo, I rule.
    • We.., *I* can solder SMPs with a *blow drier*. Ergo, I rule.

      Hmmm...the period key seems to have climbed up my keyboard. Make that "Well" instead of "We.." It looks like I will need to *seriously menace* that troublesome key with the blow drier until it descends.
  • Mom: Kids, dinner's ready! Kids: Oh boy mom! Whatcha got cookin in the oven? Mom: You're favorite... home made, roasted to perfection Intel chips (Pentiyumms?)
  • by MarvinMouse (323641) on Thursday March 27, 2003 @05:24PM (#5610331) Homepage Journal
    They can just put their site on slashdot, and let their overheated server sauter for them.
  • by Anonymous Coward on Thursday March 27, 2003 @05:35PM (#5610398)
    I have to confess I'm amazed to see someone use something as commonplace as a toaster oven to do the work of >$60,000 reflow ovens ;-) I'm an engineer in charge of a surface mount line, and there are a few interesting issues to consider when trying such techniques, the biggest of which is "ramp and soak" which in a nutshell is how hot a component gets over a given amount of time. When soldering SMT components, it is imperative that a component recieves no more than 2 degrees C (about 3 degrees F) a second ramp-up in temperature. This is to prevent thermal shock and damage to the components. It is OK for a component to be exposed to soldering temperatures, ideally for as little as possible; a few seconds. When you solder a component in an oven the way this article describes, you run a risk of damaging sensitive components. Passive components like SMT resistors, coils, and simple IC's like logic gates generally take the punishment a lot better than film capacitors, PROM's, etc. Of course, just for foolin' around in the garage, the toaster oven method should be ok, likely you'll not fry the component if you don't leave it in there longer than you have to.

    SMT reflow ovens, essentially, are identical to the ovens used in Pizza Hut where they stick a pizza in one end and it is taken through heating zones via a conveyor and pops out the other side done. In SMT reflow, the zones are controlled in such a manner that the holy 2 degrees C rule is never broken. (I used to joke that on the day I get fired, I was going to stick a frozen pizza in our reflow oven just to see what'd happen.)

    My method of soldering IC's to a board is simple and IPC approved: Place the IC on the pads; center it up as well as you can. Using a regular soldering iron, "tack" two opposing corners of the IC to the lands with conventional solder. Don't worry about bridging. Then, apply a small amount of liquid solder flux to one side of the IC, bathing the legs. Then, apply a small bead of solder to the end of you iron and GENTLY wipe this bead across all the legs, from pin one to pin whatever. (Yes, it's counter-intuitative,) and you'll see as if by magic that you'll get very few solder bridges. Apply more flux if required. Clean tip of iron completely of solder, and just touch it to solder bridges. The excess solder will "sweat" to the iron. Clean iron tip again and repeat. When done, clean flux with laquer thinner or similar substance. (If you use no-clean flux, you could just be gross and leave it there if you wished, removing excess with a paper towel.) I find that a simple toothbrush dipped in thinner does wonders.

    Or, you can stick stuff in your wife's toaster and take chances that way ;-)

    Take care now ~!
    • I co-owned a company that built fast turn prototypes. we used vapor-phase. and no matter how much I read about the temperature ramp and did experiments, the only problem with a faster temperature rise was with old parts that had been exposed to moisture. you guessed it: pop-corning. once we implemented a preheat process (10 minutes in a convection at 200F) and pre-baked multi-leaded parts of unknown storage and age, we never had a problem.
    • by Dahan (130247) <khym@azeotrope.org> on Thursday March 27, 2003 @06:29PM (#5610707)
      My method of soldering IC's to a board is simple and IPC approved

      What's IPC? FWIW, I'm definitely no expert, but I did take a course in surface mount soldering at the local community college (just for geek knowledge reasons :), and we were taught to do it the way you describe.

      Anyways, the course has been useful... I fixed a cellphone that had a tiny capacitor come loose (and I mean tiny--0.5mm x 0.5mm x 1.0mm). Also replaced a broken 0.5mm pitch FPC connector (admittedly, I did lift a pad while removing the old one... it was a pad that wasn't connected to anything though; just a small bit of metal).

    • The fast-turn prototype shop PCB Express has done some temperature profilings of several toaster ovens. You can see the results here. [pcbexpress.com]
    • When soldering SMT components, it is imperative that a component recieves no more than 2 degrees C (about 3 degrees F) a second ramp-up in temperature. This is to prevent thermal shock and damage to the components. It is OK for a component to be exposed to soldering temperatures, ideally for as little as possible; a few seconds.

      No one would argue with you on the first part - that's 100% correct, though it's probably overkill - in general most components can take thermal shock without any problems. In fac
  • Slashdotted after 1 post? Oh, my! I guess they're serving the site off a toaster, too. ;)

  • by mykepredko (40154) on Thursday March 27, 2003 @05:54PM (#5610525) Homepage
    As other posters have indicated, reflowing solder paste in a toaster oven has been done for years and simulates the standard process for SMT assembly.

    Using Solder Paste, you can use a hot air gun to place components on a PCB as well. A woman I know at work (Celestica) made a video demonstrating the SMT solder process using a hot air gun - it came out quite nicely and her joke on customers was saying that she followed the board through the oven (it was vapor phase at the time). Many customers were impressed with her tolerance to extreme heat.

    As somebody noted, most components will stop working at 140C and in the oven they will go over 200C - they will survive, but the PCB should not be powered up until the PCB has cooled to room temperature.

    If you're going to try this at home, a few comments:

    1. Solder paste will only stay reliably sticky for 30 minutes. Make sure that you have your components ready and the oven at the primary temperature before you break the seals on the syringe and start applying paste. Make sure that you don't have more components than you can place in 20 minutes.

    2. Solder "paste" is made up of finely ground solder held together by flux. Both the solder and the flux are poisenous and during the solder process you will see a build up of flux on the inside of the oven. Along with this, the solder may form "balls" that can be thrown off the PCB. An oven used for SMT experiments cannot be used for food preparation afterwards.

    3. Solder paste must be capped and refridgerated when not in use. If you are storing it in a fridge where food is stored, make sure that it is in something like a tupperwear container and well marked (especially if children are around). It looks like pate or liverwurst, but will sit in your stomach like a ball of lead (sorry, couldn't resist).

    4. The PCB coming out of the oven is very hot and will take several minutes to cool down. I've heard of a number of people that have built SMT boards in a toaster oven, only to forget oven mitts and tongs to handle the hot PCBs and ended up dropping the PCB on the floor and burning themselves. One genius I heard about was sitting down when he pulled the board out of the oven without any mitts or tongs... Make sure you have something like a barbeque grill ready for the PCB to sit on when it comes out of the over.

    5. The PCB should be as dry as possible. Before putting on paste/components, you might want to put it into the over for a day or so at the lowest setting to try and bake out any water that has gotten trapped in it. Let the PCB cool before applying paste.

    6. The PCB pads should be "HASL" ("Hot Air Solder Leveled") for best results (do not try this on bare copper and you may have to experiment with gold finishes).

    7. I would suggest using parts with leads on 0.050" (50 mil) centers, 0805 chip components and SOT-23 transistor and diodes. Anything smaller will make applying the solder very difficult. The article indicates the author used smaller spacing components, but not how many and how the PCB was laid out.

    8. Do not use surface mount connectors. Unless you are very comfortable with doing your own soldering, you will find that it is difficult to get a uniformly strong joint on every pin.

    9. If you are designing your own PCB, you can use Protel's "EasyTrax", which is an MS-DOS Command Line program that can be downloaded for free from a variety of sources (you should be able to find where on Google). I have added IPC standard pad layouts for the library components.

    I've done it a couple of times with an old toaster oven and it works surprisingly well. Just make sure you plan out what you are going to do and if there are any terms that I have used above that you are unfamilia with, make sure that you investigate them before trying it out on your own.

    myke
    • by Rambo (2730)
      Although EasyTrax works (did a couple big boards with it), Eagle [cadsoftusa.com] is much better and is also free (as in beer) for the non-profit version (limited to one schematic sheet, double sided 3x5 PCB). It has a relatively recent part library, and the nice thing is, the only difference between the "pro" version and the free version is the license file, so you're not using some crusty old unmaintained demo.
      It's available for Windows/Linux, so download away...
  • When was the last time that CowboyNeal actually posted 4 stories in a row? Is everyone else out drinking already?

    I tell you, the world's gone mad.
  • I was trying to solder a TQFP 44-pin package onto a professionally produced solder masked board. This is easier, since the solder mask helps to keep the solder away from the pads. The TQFP package is roughly 7mm x 9mm (picture here [smsc.com]), and has pins on all four sides. I used water-based solder paste (remember to keep it in the fridge) and applied it very carefully.

    I was pretty disappointed. There were tons of solder bridges (where the solder connects two pins together), some pins that didn't stick reliably,

  • since the whole process looks easier than trying to hold a soldering iron steady.
    Step one: Cut down on the caffeine.

  • eating solder (Score:3, Insightful)

    by goondu (601667) on Thursday March 27, 2003 @06:31PM (#5610723) Homepage
    i hope that toasters used in this manner get retired from toasting food products.
  • also works well for reflow of components. For rework purposes, use aluminium muffler tape to screen off the rest of the area around the component you are heating up. My recipe to remove a large chip: 1 minute at 2 inches to preheat 1 minute at 1/2 inch to reflow Flip chip off with an ice pick
  • I've been planning to try this the first time I get a board run by one of the "3 for $60" circuit board houses. Note that it shouldn't be too hard to add decent temperature control to a $30 toaster oven, though the mods would likely exceed the cost of the oven.

    THAT SAID, WHAT IS IT ABOUT SOLDERING THAT STRIKES FEAR INTO PEOPLE???

    I wish I'd thought of this back when I had to solder one of those *ahem* aftermarket accessories to my playstation, since the whole process looks easier than trying to hold a so
  • Just in case someone wants to do it the hand-soldered way:
    SMT assembly techniques [solarbotics.net]
  • by BluedemonX (198949) on Thursday March 27, 2003 @07:25PM (#5611111)
    ...they've also figured out a way to make toast with a soldering iron.
  • ...I've put up a mirror (with optimized images) here [ssai-llc.com].
  • Flux (Score:4, Informative)

    by oman_ (147713) on Thursday March 27, 2003 @08:24PM (#5611496) Homepage
    This technique is only really suitable for special case surface mount soldering.

    If you're not using surface mount components (like mod chips) you're going to have to use a soldering iron anyway.

    The key to making any iron work easy (even surface mount!) is to use plenty of flux.
    Get a seperate container of just flux and don't be afraid to use it. It makes a WORLD of difference.

  • Buy your soildering iron toaster ovens at good will! Not only does the money go to helping the poor, but you are helping keep usable appliances out of our landfills! Besides, with all the nasty stuff in the water based soldier, i doubt you'd want to cook with it afterwards. If you mod me up, mod me as informative, not funny; I'm being serious here, help out your local charity.
  • Back in the '60s (or maybe the early '70s) I saw a board for a high-end processor that used a related trick. (I think it was by Seymour Cray when he was still working for Control Data.)

    The board had some hysterical number of layers (for the time), like in the 30s or 40s. And it was literally paved with 14- and/or 16-pin DIPs. On BOTH sides.

    Now this was a problem, because DIPs have feet that go through holes and are mormally soldered on the OPPOSITE side of the board. To get maximum density the DIPs ha
    • (I think it was by Seymour Cray when he was still working for Control Data.)

      Now that I think about it, if it was Cray and integrated circuits, it would have been AFTER he left Control Data. He first used integrated circuits in the Cray I.

      He used discrete components before that, because in those days the speed advantage of discrete transistors and lower-resistance wiring sped up the logic more than the wider spacing of the parts slowed it down, so he could make faster machines that way. The crossover poi
  • ...before someone works out how to solder using an iron.

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