How I do SMT soldering in toaster oven

tonyp12 · 2011-03-09 15:43

Bad thing for us hobbiest is that the ICs are getting smaller and smaller.
It's even hard to find SOIC version of most chips.

But if you stick to biggest pin spacing chip avail and 0805 you can do it at home.

I even do the pin headers this way, just plenty of solder paste on them

At 0:50 upper left you can see 0805 resistors settling in nicely.
http://www.youtube.com/watch?v=8j0impc6ebQ

Link to oven:
http://www.orangeonions.com/product/FC150R/Black-Decker-Infrawave-Speed-Oven-Stainless.html

TonyWaite · 2011-03-10 05:22

Very impressive - I'm convinced!

T o n y

electrosys · 2011-03-10 05:52

I did my first SMT soldering by the old fashioned way, using the soldering iron and a hand-glass, it was a 28 Pin SSOP IC, and the result was much better then I was expected!
But I do not believe that I could ever solder something like that teeny tiny chip (below)

Oldbitcollector (Jeff) · 2011-03-10 08:05

@Tonyp12,

That is truly amazing! Is there any chance you could go into detail on exactly what oven you are using and the cooking times required?

Would that be this oven?

OBC

tonyp12 · 2011-03-10 08:38

I have that oven for home food use, and it's great.
For solder I use the smaller $65:
http://www.orangeonions.com/product/FC150R/Black-Decker-Infrawave-Speed-Oven-Stainless.html

The timmings are simple, on the toaster oven there is a re-heat button.
I use the deault 5min settings.
as soon that is done (the oven will beep), I press Toast Button.

It will now only take around 1 minute for the final stage and
I press Off Button 2-3 seconds after I see that the last solder have melted.

Oldbitcollector (Jeff) · 2011-03-10 08:53

Those are the details I wanted... Thanks!

Note: For others motivated to trying this it's probably a very bad idea to cook food in any toaster oven used for this purpose. I'd consider this a 'shop tool' after doing this the first time.

OBC

Ttailspin · 2011-03-10 09:15

This is just a stock oven?, no heating controller?, no hardware hacks?
I don't have to take the oven apart?

Well, this is good new's..
There are a few other post's about making an oven to work with SMD stuff.
but, I was kinda turned off by having to make up a heat control, and having to dismantle the oven.

Say, did You try any other type of oven? is it important to use the Infrared type?

Anyway's, thanks for the inspiration..

tonyp12 · 2011-03-10 09:22

No hack done.

Did try a large regular toaster oven but Infrawave is best.
Plus it's super bright so you can see if anything goes wrong.

Ofcource anything you put in there have to be high temp rated.
All SMD parts are, but barrel connectors and pinheaders etc also.
http://www.mouser.com/ProductDetail/FCI/68000-436HLF/?qs=sGAEpiMZZMtsLRyDR9nM1%252bUlhTYWPlLM8z0WE%2f%2f0Nhs%3d

Put a penny on top of some parts if you notice they move or that they get burned.
They make tape to protect from heat also.

Make sure you push down the component so it touches the solder paste on all pins/both sides.
As I have seen them stand up if there is surface tension only on one side.

You have 3 seconds trying to put missplaced part in place after you open the toaster door( it will shut off when you do)
But let it go to the full peek reflow stage first and also it's VERY HOT in there for your hand as you should not take the board out.
Moving the board rapidily could move the other parts.
And could not hurt to Toast again for 10seconds after you put part in right place.
Or at least get the misplace part out of the pcb before is cools down and handsolder it later.

The smaller the pin spacing is the less solder paste to use to avoid bridging.
But if it happens, use flux and soldering iron trying to remove the bridging.

Ttailspin · 2011-03-10 10:29

After this,

It will now only take around 1 minute for the final stage and
I press Off Button 2-3 seconds after I see that the last solder have melted

What happens next?
Is there a "cool down" time? or do I just rip open the oven door, jerk the board out and slam it into an ice water bath?

Joking about the ice bath of course, but I think I read somewhere about a cool down curve being important.
and was wondering if it makes a difference or not?

Again, thanks for sharing.

edit:
Doh... cross post... I see Your edit about opening the door now..

tonyp12 · 2011-03-10 10:54

I have open the door after 30seconds and jerked it out and cooled it down in open air.

But it's recommended when done, do not open the door.
Let it cool down for 2-4 minutes.

You are trying to get something like this temp vs time.

WBA Consulting · 2011-03-10 12:13

Excellent thread! I still haven't gotten around to documenting my toaster oven reflow, but that is how I build my PowerTwigs. I did post some detail on the whole process on another thread from UPEW 2010 because I did a full blown demonstration there. I am using a ramp to spike style profile simply because the PowerTwig has parts that are pretty flexible with profiles.

Anyhow, here's a run down of my process:

Tools:

tin-lead, no-clean solder paste (Kester EP256)
6 mil stainless steel stencil
plastic "putty knife" as the squeegee
ESD mat as the screening surface
alcohol wipes for cleanup
divided parts bin for components
tweezers for placement of parts
$40 "heating element" style (not IR) toaster oven (think it's a Magic Chef)
Small metal "cookie sheet" to place boards on
oven mitt
Candy thermometer
Fluke 377 with thermocouple

Process:

Apply paste to stencil
lay PCB on ESD mat
lay stencil over PCB and align (visually)
using putty knife, spread the bead of paste across the PCB apertures using enough pressure so that almost no paste is left across the surface. (ensures that paste is forced into the apertures, but also that the putty knife does not scoop into the aperture)
lift stencil up slowly, if the board sticks, tap the stencil to drop it off.
check paste print
use tweezers to place parts onto paste; give each a slight push to "stick" into the paste.
place boards on metal tray into room temp toaster oven
set toaster oven to 350+ and turn on
monitor temp of candy thermometer/thermocouple while watching for paste to reflow.
once paste reflows (visually see it liquify), leave oven on for about 20 seconds
turn off oven, wait 15 seconds
open oven door, wait 1 minute
pull tray from oven and set away from oven (away from heat)
once at room temp remove from tray
check for shorts on input and both outputs
test by applying 9 volt in and checking for 5.0 +/-0.1 on 5v output and 3.3 +/- 0.1 on 3.3v output
place into ESD bag with DC jack and 6 header pins
apply 1x3 product label on ESD bag
sell a lot and retire......... (as of 3/10/11, sold 94, so not retired yet)

Eventually, I will take the setup into work and run some boards through using our KIC Profiler and publish graphs. Another item on my to-do list is to actually use my DS2760 thermocouple kit and set up a prop to display temps, time, and alarms (and eventually a SSR to turn the elements on and off)

graffix · 2011-05-08 22:31

Here's where I found my info on SMT soldering in toaster oven

check here http://www.proto-advantage.com/store/product_info.php?products_id=2210070
note application pdf and two brief videos.

Ttailspin · 2011-05-09 07:20

Graffix, That link is 404... :frown:

graffix · 2011-05-09 07:32

how bout now?sorry

Ttailspin · 2011-05-09 07:40

Yup, Yup, the Linky works now...

Some good info at that sight, thanks for the link.

-Tommy

P.S. don't be sorry, Do to My other hobby, I am just a little bit 404 sensitive today...

Tom.in.Maryland · 2011-05-09 07:43

This is the temp profile I got from my SMD toster oven...

Ttailspin · 2011-05-09 07:56

Hi Tom.in.Maryland, Welcome to the Forum.

On Your Temp Profile Graph, Is the Vertical Column on the left, the Time or Temperature?
To Me, it looks to be the Time, but I was not sure.
Could You clear that up for Me?
Thanks.

-Tommy

Tom.in.Maryland · 2011-05-09 08:27

The vert axis is temp in deg C and the horz seconds. I have been using it for a few months now it is working great! The profile isn't perfect but it works thats all I need is for it to work. I have many youtube videos on it and the projects I have made with it.

Watch part 2 of YOUTUBE to see the toaster oven wiring dissected...
http://www.youtube.com/watch?v=kyphQ1WUIsk

If you want more details than are in my youtube videos on the oven (I have posted three) please let me know I would be happy to share my experiences.

I have gone SMT/SMD and will never go back to point to point wiring again if I can help it. I can eagle up a board, photo shoot it onto a positive sensitized board with a UV exposure box and have a project that has over 100 seperate connections built in four hours. Soldered up all at once. The other real main advantage is that when I did point to point wiring I made lots of mistakes. Now that my schematic is tansformed into the board by eagle I have reduced my wiring errors by 95%, I posted a youtube video this weekend of small repairs I made to wiring mistakes on a board I am working on. It is alot easier than what I was dealing with in the past, and has made increased complexity in my projects much simpler.

Now back to the SMD toster oven,,,
I highly recommend just get an oven or find one (like I did) and start dissecting it and running some boards thru it, don't wait, it will generally work without to much refinement.

When I was developing the control program for mine I was faced with PID control etc.etc. I went with a very simple approach and just run the oven heating elements in sequence based on a few tests. Without any feedback and have accomplished with one or two tries the profile posted above. I haven't had the need to modify it because it works.

Ttailspin · 2011-05-09 12:21

Ok Tom, thank You for that. I am glad I asked, as My first guess was wrong.
Looks like You have PCB's down to a science, 4 hours for a start to finished circiut board.. Nice.:thumb:

Hrmm.. wonder if there is a world record for "speed" PC board making?...

-Tommy

davidsaunders · 2011-05-09 17:08

If it interests any one I use the cheap ($18.97 US, if I remember correctly) Rival toaster ovens (the little 4 slice jobs) for my surface mount stuff, the oven is sold at wall mart and costs less than my soldering iron.

Microcontrolled · 2011-05-09 18:05

@davidsauders: What kind of soldering iron do you have, then? Mine is an $8 cheapo job that needs replacing every 6 months. :-) So what you are saying is, the oven costs as much as the solder? That doesn't seem right.....

davidsaunders · 2011-05-09 21:02

Microcontrolled:
My soldering iron is a bit cheap, it is a radio shack 15/30 watt dual heat with 7 tips, it needs replaced about once a year (some of the tips a bit more). The oven is a cheapo and needs replaced about once a year also.

kwinn · 2011-05-10 12:44

davidsaunders wrote: »

If it interests any one I use the cheap ($18.97 US, if I remember correctly) Rival toaster ovens (the little 4 slice jobs) for my surface mount stuff, the oven is sold at wall mart and costs less than my soldering iron.

I would be interested. Do you make any mods to the toaster oven?

markaeric · 2011-05-10 16:18

I've been reading that a lot of people are getting better results by using a hot plate instead of a toaster oven. The biggest challenge with that method though seems to be lifting the PCB carefully from the surface to cool the solder without jarring the components. I even came across mention of using sand in a pan to evenly distribute the heat generated by a cheap hot plate, and setting the board on top of that. I believe SparkFun is using the hot plate method for their SMD boards and achieving better results than what they were getting with their new IR reflow machine.

davidsaunders · 2011-05-10 21:02

kwinn wrote:

I would be interested. Do you make any mods to the toaster oven?

No mods, just use the stock oven. It is the $18.97 Rival 4 slice oven sold at Walmart. Just set to 250F for 5 to 6 minutes, then go up to 450F for until 4 to 5 seconds after all the solder paste is liquid, then to cool down turn the oven off, and crack the door about 2 centimeters. Apologies for temperatures in Fahrenheit, that is how the oven is labeled.

doggiedoc · 2011-05-11 04:01

Bookmarking this thread for future reference!

Paul

kwinn · 2011-05-11 20:37

davidsaunders wrote: »

No mods, just use the stock oven. It is the $18.97 Rival 4 slice oven sold at Walmart. Just set to 250F for 5 to 6 minutes, then go up to 450F for until 4 to 5 seconds after all the solder paste is liquid, then to cool down turn the oven off, and crack the door about 2 centimeters. Apologies for temperatures in Fahrenheit, that is how the oven is labeled.

Thanks for the info, much appreciated. No apology for Fahrenheit necessary. At home in both C and F.

Ttailspin · 2011-05-13 17:45

I really don't have any experience with surface mount soldering, so its time for some hands on...

Picked up one of those little rival toaster ovens for under $20 at wal mart, and now, I will need the solder paste.
Are there any solder paste favorites? I just want to experiment on some home made PC's, and nothing commercial.
I was looking at the little 5cc syringes for $20 with shipping, but how far will 5cc get me? 10 pads? 100 pads?
Any hints, tips, or pointers for the where and what of solder paste?

-Tommy

Tom.in.Maryland · 2011-05-14 13:22

I've posted three videos on my Youtube channel that you should be interested in.

One is on drilling,
another on Paste, and
another on Vias.

here are the links...

http://youtu.be/Qifv-GkI96k
http://youtu.be/CO2Vv0YztBE
http://youtu.be/9HY6jsjjdfs

As for where to get the paste, I would recommend this company, it seems they are a home "cottage" buisness" (not sure) and they have great service, the owner knows about electronic assembly with his products and will answer questions. I recommend the syringe flux too. http://www.cmlsupply.com/

Finally,

For those interested in youtube videos of my Homebrewed Printed Circuit Board
fabrication, PIC chip experiments, High powered LED projects, Arduino
applications, QRP kit builds, and Electronics Tourism, Please take at look and
subscribe to my new improved youtube channel "Hamradio2008"
link...
http://www.youtube.com/user/HamRadio2008
heres a current video; Back from Silicon Valley:
Back from Silicon Valley _ LeCroy WaveAce 112
http://www.youtube.com/watch?v=MQ2-a1oB57Q

Tom.in.Maryland · 2011-05-14 13:36

I've posted three videos on Youtube that you should be interested in, one is on Drilling, one is on Paste, and one is on Vias

http://youtu.be/Qifv-GkI96k
http://youtu.be/CO2Vv0YztBE
http://youtu.be/9HY6jsjjdfs

Tom.in.Maryland · 2011-05-14 13:38

I would recommend CML supply to get one syringe of paste and one of flux.

For those interested in youtube videos of my Homebrewed Printed Circuit Board
fabrication, PIC chip experiments, High powered LED projects, Arduino
applications, QRP kit builds, and Electronics Tourism, Please take at look and
subscribe to my new improved youtube channel "Hamradio2008"
link...
http://www.youtube.com/user/HamRadio2008
heres a current video; Back from Silicon Valley:
Back from Silicon Valley _ LeCroy WaveAce 112
http://www.youtube.com/watch?v=MQ2-a1oB57Q

How I do SMT soldering in toaster oven

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