Toaster Oven Reflow Soldering (BGA)




Doing solder reflow work can be expensive and difficult, but thankfully there exists a simple and elegant solution: Toaster Ovens. This project shows my preferred setup and the tricks that make the process run smooth. In this example I'll focus on doing reflow of a BGA (ball grid array).

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Step 1: Find a Toaster Oven.

You're looking for two main things, an adjustable temperature knob, and a timer that will time down. The more precision you can get in the timer the better.

Also, if you can get it, some sort of forced air flow will improve the uniformity of the oven temperature, but you have to make sure that the air flow isn't powerful enough to move your components around.

Step 2: Get a Thermometer and Timer.

Even though the toaster oven has a temperature set point and an integrated timer, you still want to get some more accuracte readings. Get a cheap oven thermometer and toss it inside the oven and get a timer with an alarm to remind you to check on your baking PCBs.

Step 3: Make Your PCBs.

In this exampe I'm working with an ADXRS300 which is a 1 axis Gyrometer made by Analog Devices. It comes in a ball grid array package with the balls already attached to the bottom of the component. The PCB needs to be designed with pads for each of the balls, along with a silk screened outline to make it easy to align the component (which is critical when you can't actually see the pads). Also, duh, make sure you mark the location of Pin 1.

Step 4: Add Flux to the PCB.

The balls in the BGA don't have flux so you *absolutely* have to put down flux on the board prior to doing the reflow. If you don't add flux then the oxide on the top of the pads will keep the balls from flowing and you'll end up with slightly squished balls that are not actually connected to the underlying PCB.

Step 5: Align the Components on the PCB.

Position the PCB on the tray of the toaster oven, preferably oriented so that you can keep an eye on it through the window of the oven. Precisely position the component on the PCB using the silk screened outline to do the alignment. You don't have to be exactly accurate since the solder reflowing will actually pull the component into alignment, but you should try to get it as close as possible. Worst case scenario would be having the component offset by more than half of the ball spacing pitch which would cause the component to shift over by one set of pads. Not good.

Step 6: Start 'em Cooking.

Close the toaster oven door, (make sure you don't bump the component out of alignment.) Set the temperature dial for somewhere around 450 and start the timer at around 20 minutes. Later on once you've determined the characteristics of your particular toaster oven then you can start using exact values. But for right now we're going to use our oven thermometer and the external timer to keep track of what's happening.

Step 7: Watch the Temperature.

Keep on eye on the thermometer. You'll have to check the reflow profile for your particular components to know what temperature you're trying to reach. In my case, the solder balls would start to melt at 183C and I wanted to hit a top temperature of 210C. If you go beyond 230-240C you'll start to incinerate your PCBs, which although amusing, is probably not what you want.

Step 8: Turn Off the Toaster Oven.

As soon as the oven hits the top temperature you're aiming for, turn it off!

Step 9: Let It Cool, and Don't Move Anything!

You can speed up the cooling process by opening up the front door of the toaster oven... BUT, make sure you don't jostle the components or move them in any way. The solder is still liquid at this point and if you poke at the component you will shift it around and ruin it. This is the time to just walk away. Once the temperature drops below 100C (or 50C if you're paranoid) you can feel free to move things around.

Step 10: Inspect and Enjoy.

You should make sure that all of the balls are connected and that the component is strongly attached to the PCB. This image shows 3 of the reflowed BGAs integrated together in a 3-axis Inertial Measurement Unit.

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    61 Discussions


    3 years ago

    That was cool! Now that I recently got my first solderscreen PCB is time to start thinking big cooking little stuff as you. Thanks for sharing!


    4 years ago

    Works well for desoldering. I was able to recover some nice fets this way.


    4 years ago on Introduction

    Oh my god, i feel like such an idiot right now. I tried this a while ago, but instead of fluxing up the pads, I tinned them. It didn't work.

    Now that I look back on it, a flux pen would have worked so much better. Tacky flux even better than that...


    4 years ago on Introduction

    Do NOT use an oven thermometer!! You would be lucky if they were +/-10 C

    The best thing to use is a thermocouple, which you can plug into a lot of the better multimeters. My Fluke DMM takes a K-type thermocoupld input. One of the other good things is that the sensing element is a tiny bead, so you can put it right next to the parts you are soldering and get really good accuracy.

    Do not attempt to use the temperature control knob on the oven. The best thing to do (unless you want to make a PID controller) is simply turn the temp full on, then ride the on/off knob to try to match the profile.

    Also - download the temperature profile from the solder manufacturer and try to follow it. This will be a temperature vs. time graph. It is important to try to follow the rates. If the rise rate is too fast, put a chunk of scrap metal in the oven. During the cooldown phase, I found opening the oven door just a tiny crack got it just about perfect. Don't open the door all the way or take stuff out until the temp is less than 100F.

    Finally - if the parts have been lying around, they will have absorbed moisture and must be baked before soldering (or they will popcorn). Make the oven warm without being really hot ( 120 F or something like that) and leave them in for a while.


    5 years ago on Step 2

    You say,

    " still want to get some moreaccurate readings. Get a cheap oven thermometer and toss it inside the oven..."

    No. Do not do this! Think about it. You're putting a cheap thermometer in the oven to get,

    "...some more accurate readings."

    This makes absolutely no sense and might very well be setting you more off track than using the default toaster oven thermometer & timer.

    1 reply

    Cheap doesn't mean low quality or worse accuracy, cheap means less money. If for 0.0001 degree more accuracy you have to pay 1000 more times you don't need, it doesn't mean that 0.1º being much cheaper is worse. For reflowing 0.1º doesn't matter really, but for eye surgery it does. Anyway since we don't know the characteristics of both thermometers, we can't guess anything.

    Surely the a nice solution in this case is locate the built-in temp probe and move it to a better place.


    5 years ago on Introduction

    "You should make sure that all of the balls are connected and that the component is strongly attached to the PCB". How to check for the connections of the balls of the BGA ic?


    6 years ago on Step 6

    For the temperature control you can improve your oven by adding a PID controller. I you are not familiar with them you can use the ones specially designed to transform domestic ovens in n_electronics (, adafruit ( or drotek (
    Like that you will be able to achieve nice soldering profiles without the need of a external timer and the risk of damaging the components is much lower.


    7 years ago on Introduction

    Awesome! I was afraid I wouldn't be able to use a FPGA BGA chip and I would have to resort to the less robust: quad flat pack version. Thanks!


    8 years ago on Step 4

    When doing SMD stuff at work I tend to use "tacky" flux which comes as a gel. It not only serves as a flux but makes positioning IC's a lot easier as you can sit them on top of a little blob of it and then fine tune their position with your tweezers (aligning TSSOP48's would be pretty much impossible without it IMHO) It also helps stop things getting blown about in the oven too!


    9 years ago on Introduction

    hey, although this worked with my laptop's video card awhile ago, i just tried it with a desktop motherboard at the temperatures you specified and it melted the plastic and caused one of the capacitors to explode... ruining a perfectly good motherboard that just needed a simple fix. :(

    I looked further into reflow and other resources say that the temperature should be between 390F to 420F. NOT 450F. please edit your instructable so other people don't make the same mistake i did.

    also, try not the breathe the smoke in that is released from the motherboard, I accidentally did and now I feel light headed.

    6 replies

    Reply 8 years ago on Introduction

    Valuable life lesson here if you can forgive yourself for damaging your board. Always seek out more than 1 source of information.

    The author's example is building a BARE PCB up with no mention of plastic.
    The author could not anticipate that someone would try to reflow plastic parts, or inhale the fumes. You can not document common sense in the space of a tutorial.

    Since you wanted to reflow a populated board, I would have sought one of those tutorials out (there's lots of them, particularly for the x-box, as reflowing the board is something many customers have needed to do).

    By the way, your motherboard was not ruined. Capacitor replacement is one of the easier repairs to make. $3 on ebay would get you a replacement cap of the right size, and you could solder it back in with a cheap iron.

    I'll also throw in, if you want to do localized reflow without heating the whole board, a heatshrink gun can work (Sparkfun has a Heaterizer 2000 for like $10). You can still make mistakes of course...

    If the part is valuable and you are a novice, best to watch someone else do it the first time (youtube is good for this!)


    Reply 8 years ago on Introduction


    it was a crappy little socket 478 mobo anyway, Yes, lesson learned, atleast i didn't do it to a more expensive component.


    Reply 8 years ago on Introduction

    A cheap screw up then. :D

    Reflowing "smt" chips, resistors, caps, or any other "surface mount" components on a motherboard is the FIRST process they do to it.. BEFORE adding the other components that are "heat sensitive".. ie: "melt at high heat". The plastic based components are added later.. by hand.

    Think of it this way.. would you allow your motherboard to run at 390F - 450F? No. Reason is, those plastic components will fry.

    There's nothing wrong with this method. Many use their bigger ovens as well. You just need to be sure you are familiar with electronics before you attempt to do something like this.

    If you need something directed at a single component on the board, then look for the instructables called "DIY Hot Air Soldering Iron". A "reflow pen" is what you need. More control of where the heat is applied. ;)



    Reply 8 years ago on Introduction

    some people have used butane jet lighter style torches to reflow components with high levels of success, i tried and had i not accidentally pulled off some pads (because i didnt wait) the palm pilot would have worked fine again.

    people have used these torches for laptops more specifically, since most people arent smart enough to try it ont eh desktops, since they figure motherboards are eas to replace anyways.


    Reply 9 years ago on Introduction

    Lead-free solder has a higher melting temperature. 420F/215C is peak temperature for lead bearing solder which is ban after year 2002, Lead-free solder has peak temperature of 450F/232C for 1 min or 425F/217C for 3 min..... Never reflow PID's and plastic parts in IR oven together with SMD's without covering them with kapton tape.


    Reply 9 years ago on Introduction program it yourself. and sparkfun's toaster oven works better than their reflow oven :P


    9 years ago on Introduction

    Nice job. I have done thousands of BGA profiles professionally and I like how this boils it down to the basics time and temp.  the only thing I would do is rewire the oven so both elements run together so you soak through the component. I think that will get everything up to 183c (for lead solder and 205-230c lead free solder) pretty quick. on the other hand, if it's not broke don't fix it.