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Anyone here ever used a toaster oven to solder the LQFP or QFN Propeller packages? — Parallax Forums

Anyone here ever used a toaster oven to solder the LQFP or QFN Propeller packages?

ElectricAyeElectricAye Posts: 4,561
edited 2012-09-12 18:04 in Propeller 1
I've seen a number of threads suggesting people have had some good luck using toaster ovens + solder paste to make some PCBs using SOICs and so forth, but I haven't yet found anyone mentioning they have used such a DIY home-growth method on the LQFP or QFN Propeller packages.

Has anyone had any luck using a DIY toaster with the LQFP or QFN Propeller?
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Comments

  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2012-09-09 20:23
    Yes, I've soldered the LQFP version in a toaster oven, with great success. Sometimes, though, a bit of solder wick is necessary for ... um ... postprocessing.

    For me the key has been the solder paste. I've have nothing but praise for ZephPaste. Its reflow performance and shelf life are both extraordinary, compared with the Kester Smile I got from DigiKey.

    -Phil
  • Peter JakackiPeter Jakacki Posts: 10,193
    edited 2012-09-09 20:25
    I don't have any luck with the Propeller. Well when I say "no luck" I mean luck has nothing to do with it :) It just works, easy peasy. I just run a bead of paste across the tracks all the way around, smudge on a chip, align it, bake it.
  • Martin HodgeMartin Hodge Posts: 1,246
    edited 2012-09-09 20:28
    Dozens of QFP and TSOP in a toaster oven for me. I use flux and drag soldering to clean up the pins afterward.
  • Peter JakackiPeter Jakacki Posts: 10,193
    edited 2012-09-09 20:30
    Phil Pilgrim (PhiPi) wrote: »
    Yes, I've soldered the LQFP version in a toaster oven, with great success. Sometimes, though, a bit of solder wick is necessary for ... um ... postprocessing.

    For me the key has been the solder paste. I've have nothing but praise for ZephPaste. Its reflow performance and shelf life are both extraordinary, compared with the Kester Smile I got from DigiKey.

    -Phil
    I will have to try that paste out. I also use a dispensing gun which I kinda hold upside down using both hands as it sure makes it easy to dispense without straining your hand.
    Dispensing gun.png
    Dispensing gun.png
    606 x 461 - 114K
  • ElectricAyeElectricAye Posts: 4,561
    edited 2012-09-09 20:36
    I am humbled and astounded at the speed and quality of the responses to my question! Thanks, everyone, for providing me with some encouragement on this. Of course, I know all of you are experts at this sort of thing, but maybe there's hope if I give it a go.
  • Peter JakackiPeter Jakacki Posts: 10,193
    edited 2012-09-09 20:42
    BTW, there's lots of little tips I can give you about "home baked chips". One of them is so simple, don't place your board directly on the rack, put it on a small sheet of aluminium foil folded up about 4 layers deep. The foil cushions the pcb and parts from vibration and makes it easy to handle even if it has parts already baked on the other side. I might have to start an SMD home baking page. I do small production runs so I have produced thousands of boards this way.
  • ElectricAyeElectricAye Posts: 4,561
    edited 2012-09-09 21:04
    Peter Jakacki wrote: »
    ...I might have to start an SMD home baking page.....

    Yes, please do! I'm sure plenty of people would like to see how this is done by someone knowledgeable, especially considering how it's getting harder to find through-hole components that keep up with the times.
    Thanks for the tips, too!
  • SandfireSandfire Posts: 32
    edited 2012-09-09 21:38
    Yes, absolutely!

    Please do this Peter.
  • Martin HodgeMartin Hodge Posts: 1,246
    edited 2012-09-09 22:24
    Peter, my thumb really wants me to get one of those guns.
  • frank freedmanfrank freedman Posts: 1,983
    edited 2012-09-09 23:27
    Peter Jakacki wrote: »
    I will have to try that paste out. I also use a dispensing gun which I kinda hold upside down using both hands as it sure makes it easy to dispense without straining your hand.
    Dispensing gun.png

    Wish I had that!!! Zephpaste is tough to extrude through an 10cc syringe and 20g needle. But it is great paste seems to remain useable well after its stated shelf life if stored right. I have used it on occasion with a home-made air soldering tool. Yes the same one someone posted on youtube sometime back using a Radio Hhack desoldering iron and a low airflow from an aquarium pump regulated by simple aquarium grade air valves. Loose the squeeze bulb and replace with hose from the aquarium pump. I have used this to mount QFN-56 USB hub chips, connectors, sioc and t/ssop formats. also some passives. It will not do an effective job at removal. For that I have access to a bottom feeder Ayouy model.
  • william chanwilliam chan Posts: 1,326
    edited 2012-09-10 01:41
    Peter Jakacki wrote: »
    I just run a bead of paste across the tracks all the way around, smudge on a chip, align it, bake it.

    Sorry, I am not so clear on your technique.

    Do you mean that squeeze out a snaky long paste or you squeeze inidvidual small amounts of paste on each pad?
  • RDL2004RDL2004 Posts: 2,554
    edited 2012-09-10 05:59
    There was a video on this at eevblog.com just recently. Dave used a hot air gun, but it does demonstrate the application of the solder paste.
  • tonyp12tonyp12 Posts: 1,951
    edited 2012-09-10 06:21
    I do 0.5mm QFN in infra-toatser oven all the time, use as little solder paste as possible and smearing across pads is OK.
    Use landing pads on pcb that sticks out further helps too.
    Some post- work with soldering iron and flux is sometimes needed to remove large solder ball across two pads.
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2012-09-10 07:08
    william chan wrote:
    Do you mean that squeeze out a snaky long paste or you squeeze inidvidual small amounts of paste on each pad?
    For me, that depends on the lead pitch. Up to and including SOIC parts, I will paste individual pads. Beyond that, a thin stripe through a row of pads seems to work fine.

    BTW, for those who do not already have toaster ovens, get an IR unit with a convection fan. Mine doesn't have the fan, which makes it impossible to do boards larger than a few square inches, due to the uneven distribution of heat.

    -Phil
  • ElectricAyeElectricAye Posts: 4,561
    edited 2012-09-10 07:10
    Phil Pilgrim (PhiPi) wrote: »
    ...
    BTW, for those who do not already have toaster ovens, get an IR unit with a convection fan. ...

    Thanks, Phil. Anybody know of a particular unit you know is good?
  • lardomlardom Posts: 1,659
    edited 2012-09-10 07:45
    @ElectricAye, Let us know how well you do. I have "Kester" paste and four QFN chips which I'm afraid to touch.
  • 4x5n4x5n Posts: 745
    edited 2012-09-10 17:42
    Phil Pilgrim (PhiPi) wrote: »
    For me, that depends on the lead pitch. Up to and including SOIC parts, I will paste individual pads. Beyond that, a thin stripe through a row of pads seems to work fine.

    BTW, for those who do not already have toaster ovens, get an IR unit with a convection fan. Mine doesn't have the fan, which makes it impossible to do boards larger than a few square inches, due to the uneven distribution of heat.

    -Phil

    I haven't done any SMT work yet but I'm interested in getting started. Do you have a make and model in mind? I don't own one and as long as the cost is $150 or less I don't care which one I get. If it's more that $150 I'll have to think about it. :smile: I've got my eye on a hot air smt hot air rework station for that amount.
  • TubularTubular Posts: 4,706
    edited 2012-09-10 18:39
    Phil Pilgrim (PhiPi) wrote: »
    For me, that depends on the lead pitch. Up to and including SOIC parts, I will paste individual pads. Beyond that, a thin stripe through a row of pads seems to work fine.

    BTW, for those who do not already have toaster ovens, get an IR unit with a convection fan. Mine doesn't have the fan, which makes it impossible to do boards larger than a few square inches, due to the uneven distribution of heat.

    -Phil

    We've been doing proto Eurocards (6.3" x 4") successfully here, with about 50 ics onboard, using a ~$20 Tiffany. Virtually no rework required. It has two elements, a half shielded one at the bottom, and unshielded one at the top, no fan.

    A convection fan may be preferable, especially if there is a wide variety of component sizes, but probably not essential to get started.

    I've been amazed at how forgiving it all is, and wish I started earlier.
  • Cluso99Cluso99 Posts: 18,069
    edited 2012-09-10 19:45
    Peter: Where did you get that hand gun from?
  • Peter JakackiPeter Jakacki Posts: 10,193
    edited 2012-09-11 01:51
    Cluso99 wrote: »
    Peter: Where did you get that hand gun from?
    Okay Technologies Online a local supplier where I get my pastes and other supplies from.
    http://www.okay.com.au/okay2009/product_info.php?cPath=1013_617&products_id=2951
  • average joeaverage joe Posts: 795
    edited 2012-09-11 02:40
    Phil Pilgrim (PhiPi) wrote: »
    For me, that depends on the lead pitch. Up to and including SOIC parts, I will paste individual pads. Beyond that, a thin stripe through a row of pads seems to work fine.

    BTW, for those who do not already have toaster ovens, get an IR unit with a convection fan. Mine doesn't have the fan, which makes it impossible to do boards larger than a few square inches, due to the uneven distribution of heat.

    -Phil

    In my experiments several years ago, I found that IR with fan works WAY BETTER. I tried several different models *from a thrift-store* and the best ones had fans. I would recommend a good controller, the built-in temp settings will drift out of spec.

    Best results: IR with fan, fan always on, element controlled by micro. 2 thermocouples, one dead center under board, one halfway between wall. A simple averaging of temps to control set point worked great.

    For doing more than a board here or there, solder paste dispenser is worth its weight in gold.

    Good luck!
  • groggorygroggory Posts: 205
    edited 2012-09-11 16:29
    I've never used the toaster oven method, but I've had great success with the electric skillet method
  • Jim FouchJim Fouch Posts: 395
    edited 2012-09-11 17:53
    http://www.amazon.com/Frigidaire-Professional-6-Slice-Convection-Toaster/dp/B005O377UO/ref=sr_1_9?s=home-garden&ie=UTF8&qid=1347410875&sr=1-9&keywords=infrared+oven+convection

    Does this look like a good unit to modify and use a Prop or something to control it. I could see a USB Proto Board being used to have a PC control the whole process.
  • ElectricAyeElectricAye Posts: 4,561
    edited 2012-09-11 18:06
    Jim Fouch wrote: »
    ... I could see a USB Proto Board being used to have a PC control the whole process.

    It seems like you'd be paying for the fancy LCD and then bypass the whole thing with your own controls. Just wondering: why would you need a PC to control the process if you've got a Prop Board controlling it? I'm guessing the Prop by itself would be able to handle the temp/time profile very easily.

    I wonder how hard it would be to get a cheaper IR oven, then install a DIY fan?
  • Jim FouchJim Fouch Posts: 395
    edited 2012-09-11 18:46
    ElectricAye wrote: »
    It seems like you'd be paying for the fancy LCD and then bypass the whole thing with your own controls. Just wondering: why would you need a PC to control the process if you've got a Prop Board controlling it? I'm guessing the Prop by itself would be able to handle the temp/time profile very easily.

    I wonder how hard it would be to get a cheaper IR oven, then install a DIY fan?

    The PC, would only be needed if you wanted to easily modify the settings, or show feedback.

    I guess I got the idea from this video
  • ElectricAyeElectricAye Posts: 4,561
    edited 2012-09-11 18:55
    That's an awesome machine. But I'm hoping it's overkill, otherwise my hopes for DIY reflow are cooked.

    I wonder if Phil Pilgrim's new Thermal Imaging system will be able to work with this.
  • Jim FouchJim Fouch Posts: 395
    edited 2012-09-11 19:09
    ElectricAye wrote: »
    That's an awesome machine. But I'm hoping it's overkill, otherwise my hopes for DIY reflow are cooked.

    I wonder if Phil Pilgrim's new Thermal Imaging system will be able to work with this.

    Here is a more down to earth one. They show how to create one out of an old BlecknDecker unit.
  • Martin HodgeMartin Hodge Posts: 1,246
    edited 2012-09-11 19:11
    GAH! Finger pistols!
  • average joeaverage joe Posts: 795
    edited 2012-09-11 19:37
    RE: Old toaster ovens (and adding fans): These work GREAT if you're very careful about the algorithm for controlling temp.

    I seem to remember from my testing that older "thrift-store" models required more ramp-up time. Not much, but enough to cause some temp drift between heating cycles.
    It also works best to turn off JUST BEFORE temp. Results may vary with unit.
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2012-09-11 19:43
    I don't mess with PC-controlled temperature profiles. It's all done manually. I have a pre-heat phase at a lower temperature that lasts 2.5 minutes, followed by a reflow phase at a higher temp that lasts anywhere from 30 seconds to one minute, depending upon what I see happening through the glass door. As soon as reflow is done I open the door for the cool-down.

    -Phil
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