Commercial Reflow ovens for Hobbyists

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1

So I already have my own reflow oven that I built using a reflow controller from TheSiliconHorizon and a cheepie oven, but it’s not the idea setup at the moment, and before sinking more money into a IR oven to mod, I found these;

If you search ebay for “T-962 IC Heater Infrared Reflow Wave Oven” you will get a whole load of results for a reflow oven priced at around $300usd. Obviously it is cheap and that will probably be reflected in quality, but for $300 it doesn’t seem like too bad of a thing.

I have probably already spent $100usd and I got my oven for free. If I go and buy a bigger IR oven to mod I will probably end up spending close to the price of one of these anyway, and it sure would be nice to have a self contained unit, made for the job.

So what I am wondering is if anyone has had any experiences with these reflow ovens before.

(Before you say it, I know I can use a skillet, mod a bigger oven etc, but that’s not the point. At the end of the day these are all “hack-jobs”, im interested in something a bit more professional without the time and effort.)

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That looks exactly the same as a unit a friend of mine got from China. His unit works very nicely, and is now being used for small-scale manufacturing.

I’d say the best idea would be to Google for comments on a particular supplier you’re looking at, but in general these ovens look like a good way to go.

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They all seem to be made by the same company in china, at least the ones on eBay.

I might bite the bullet in a month or two and see how I go, it’s not too much money to loose if it’ rubbish.

If I do get one I will post back a review here for sure!

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Id say go IR from the start (which is what we recommend).

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if you checkout the 20+ pics and reflow graphs in our manual you will see exactly what your getting with a known setup of an www.omega.com K type thermocouple, a black and decker infrawave oven, and our controller using an omron SSR.

no guesswork, no nothing.

:slight_smile:

but no i havent seen the one on ebay up close.

i like the roller bearing drawer, thats cool.

6

Dragging up more old topics?

Your obviously didn’t read the topic title, it says commercial meaning something you buy off the shelf, plug in and use.

Your reflow controller is just that, a controller, and a DIY solution.

Normally I don’t mind your posts but don’t go dragging up months old topics just to advertise your stuff. I already said in the OP that I already had your controller and was looking for something else.

7

i sincerely apologize.

obviously you dont like me and i will no longer respond to your posts.

thanks and have a great day

please dont get angry.

life is too short to get angry.

smile a little.

8

I have the T-962 oven and my impression is that you get what you pay for. It does serviceable work for small PCB’s, but you should not expect consistent heat towards the front and back extremes of the heating surface due to the positioning of the IR tubes across the center of the oven.

It also gives off pretty bad fumes when running. I had to relocate it to a small bathroom with an exhaust fan to avoid getting a sore throat.

When the cool-down fan comes on, it exhausts the hot air through vents on the bottom of the unit. This will make the surface it sits on very hot and could damage or burn that surface. In my case, I used a layer of fiberglass batting and a sheet of steel over the surface to avoid heat damage.

And then there is the embedded firmware…

*The keypad is not debounced, meaning that sometimes you have to quickly stab the buttons to get it to work.

*The control loop is just bang-bang rather than PID, resulting in quite a bit of temperature variation.

*The heat turns off if the actual temp is within 5 degrees C of the set point, so it is always a little cooler than it should be.

*The fan turns off if it is within 10 degrees of the set point, leading to big temperature swings in the cooling off phase.

*The data shown on the LCD graph appears to be fudged, since the “Actual” points are always higher than the “desired”, in spite of the numeric readouts which suggest the opposite.

*The designer of the user interface appears to have gone out of their way to make things counter-intuitive (e.g. a button on the left moves the cursor to the right).

This would be a much more usable machine with different firmware. Perhaps this could be an interesting open-source hacking project.

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ok i lied.

i am going to reply.

given the above review stop on by to www.thesiliconhorizon.com and see our controller.

yah you have to put it together with your own oven… but with an IR oven you will get better performance based on what is said above.

and you can pick from 3 algorithms.

and we have 3 algorithms to choose from

check this out.

http://www.thesiliconhorizon.com/images … l100ms.jpg

it has great control (when you tune the PID on your setup).

yah you have to put it together but its worth it.

remember we recommend an IR oven such as the black and decker which is what all our graphs are based on.

btw: you can checkout our manual for like 20+ graphs using the black and decker infrawave and all the parameters of the reflow session (time, algorithm and gains) are in the title, so there is no guesswork to reproduce the same thing that we have.

sooooo… you could go with china cookie, or go with us, a proven solution and we have sold 1000’s of these babies to everyone and most people are happy with it that have the skill level to hack an oven.

if you dont have the skill level to hack an oven, then i recommend the china version above :slight_smile:

but that roller bearing slideout tray is cool :slight_smile:

thanks for letting me blurb.

we do have a great solution and we are always updating the software.

the windows software sourcecode is not included however at this point in time.

sometime next year we may be releasing that as well.

btw: yes we do support any linear mV/C sensor like www.omega.com engineering’s infrared thermocouple boxes… they work great off of our PID loop and you can still watch a 2nd temperature with another sensor… all selectable in the GUI.

and she talks to you!!! :slight_smile:

now im sure gussy is gonna beotch at me, but thats cool, i kinda hijacked this thread.

thanks for listening guys, and think of us as your solution :slight_smile:

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oh yah we are carrying 6 foot USB cables now too :slight_smile:

i have a 20 footer around here hahahaha that i use…

ethernet may be a nice option :slight_smile: maybe in the future.

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I think the controller idea is cool but probably overkill.

I turn on my hotplate on max. Wait 5 mins. Turn it to medium. Put the board on. Turn it back to high. I watch it for 5 minutes or so and when it reflows I remove it.

I watched the profile carefully with a thermometer and the hotplate doesn’t heat up fast enough to follow most recommended profiles.

Your board isn’t going to jump from 200-300deg in a few seconds so it’s fine just to watch and remove when it’s done. I understand if it’s inside a toaster oven you will have a lot harder time looking at it or want to walk away for 5 minutes and do something else than automatic control would be useful. However 5 minutes is pretty short so watching it is easiest unless you are doing a lot of boards.

The basic idea is that solder either reflows or it doesn’t. If you turn your hot plate to max, it’s not going to get hot any faster. Once it has reflowed, you remove the board from the plate. It’s not going to cool any faster so there’s no point to finer temperature control.

Save your time and money and buy a hot air gun instead from ebay. I don’t even use the hot plate anymore. Just heat it for a few seconds and the components solder. Also it doesn’t heat the rest of the board so much safer to prevent board warping. You can combine with the hot plate to hit problem areas that are taking longer but I find the extra heat and power produced by the hot plate is more hassle than it is worth.

Search “852D solder*” on ebay. Best $100 I spent in a long time.

Again if you have a pair of eyes and 5 mins just watch the board. When it’s done it’s obvious. If it’s not done, there’s not much else you can do except wait. That is the safest/easiest/cheapest method.

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i think a hot plate is a good solution for some people.

sparkfun has an excellant tutorial on how to use one to reflow :slight_smile:

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This should be easily replicated with arduino/processing. Anyone know of an open source project?

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George, just some info so you can get your facts straight.

When I posted this thread, I already had one of corvette123’s reflow controllers, and was asking about alternatives. He knew this, and still replied telling me how good his controllers were, even though I already had one, and I specifically said in the first post that I wasn’t looking for a controller like his.

Therefore, there was no need to post in here, except for blatant advertising, which it seems worked on you at least.

15

sarmitage:
I have the T-962 oven and my impression is that you get what you pay for… It also gives off pretty bad fumes when running. I had to relocate it to a small bathroom with an exhaust fan to avoid getting a sore throat… This would be a much more usable machine with different firmware. Perhaps this could be an interesting open-source hacking project.

This is about right. The issue is the internal construction uses masking tape to hold the fiberglass insulation in place, and even scarier, to insulate the connection to and as grommets for the elements(!) They had what looked like floor tile pieces wedging things in here and there.

I gutted the whole thing, bought some sheet brass, new fiberglass and high temp silicone sheet at Tokyu Hands (I’m sure such things can be had elsewhere, it’s just easier in Japan) and redid all the internals, building heat shields and some ducting for the fan with the brass. It’s very simple construction, it’s just an evening’s work if you’re so inclined.

I also wanted off-then-shelf… but the stock T962 wasn’t safe to use. The other problem is you really have to heat soak for a long time with the T962 if you’re doing QFN or BGA… I’ve not got a reliable recipe for that yet. Small parts or QFP, works great (did before, except the burning tape/floor tile/plastic fumes) It’s just a simple ATmega controller, I’m sure it would be “only” a few days work to rewrite it’s horrible firmware… but at least it mostly works in spite of it’s self.

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The other problem is you really have to heat soak for a long time with the T962 if you’re doing QFN or BGA… I’ve not got a reliable recipe for that yet.

Yes, it has no bottom heat, so you need to slowly raise the heat to make the whole board heat up properly. I find that 5 degrees C per 10 sec step works well. You may also find that fiber washers under the board will help prevent the cold drawer surface from drawing away the heat.

It’s just a simple ATmega controller

That's interesting. Mine has a LPC2144 ARM7. Either way, a rewrite would be feasibile.
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djd328:
This is about right. The issue is the internal construction uses masking tape to hold the fiberglass insulation in place, and even scarier, to insulate the connection to and as grommets for the elements(!) They had what looked like floor tile pieces wedging things in here and there.

I gutted the whole thing, bought some sheet brass, new fiberglass and high temp silicone sheet at Tokyu Hands (I’m sure such things can be had elsewhere, it’s just easier in Japan) and redid all the internals, building heat shields and some ducting for the fan with the brass. It’s very simple construction, it’s just an evening’s work if you’re so inclined.

I also wanted off-then-shelf… but the stock T962 wasn’t safe to use. The other problem is you really have to heat soak for a long time with the T962 if you’re doing QFN or BGA… I’ve not got a reliable recipe for that yet. Small parts or QFP, works great (did before, except the burning tape/floor tile/plastic fumes) It’s just a simple ATmega controller, I’m sure it would be “only” a few days work to rewrite it’s horrible firmware… but at least it mostly works in spite of it’s self.

About the mods you did on the T-962… Would you be so kind and share us in more detail on how you did it? So as for those who already has a T-962… Pictures will be very much appreciated…

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I am also having problems with my T962. It burns the PCB directly under the heating elements while not melting the solder paste elsewhere. Detail of any modifications would be gratefully received!

DC REdD

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I have never been happy with the skillet / hotplate. As an ME I just can’t reconcile how heat will travel through a fiberglass board with multiple heat contuctors (via’s and traces) and not have hot/cold spots. Many times I will put exposed copper on both sides of the board for heatsinking - and I can just feel that hotplate roasting the Power IC’s due to the better thermals of the heatsink with numerous vias.

I have used hotplates on aluminum backed boards (for LED’s) with some success.

I would not be comfortable using a hotplate on complex boards especially with small SMT connectors and electrolytics. Electrolytic caps can and are damaged by temperature spikes and are giving people fits as the ramifications of temp spikes during reflow may not show up for 6 months to a year. Basically they can get their lifespan cut significantly. Think of all the Mitsubishi TV’s or Escort Radar detectors that have died due to dead Electrolytics. CM’s will tell you that RoHS has significantly increased the problem due to the higher reflow temps.

All that being said I have tried it and it “works” but again - my comfort level is low.

I do have the TechFX controller and using the B&D oven I put together a working unit in a few days. I think I have an old rev of the controller so I may get around to buying another soon (the controller is cheap - the other parts add another couple of hundred including oven). It gives me some problems not kicking off a cycle occasionally (have to reboot the controller) - but all in all seems stable as hell. I need to rig up a vented cool-down at some point as opening the door spits out a nasty fume plume. It does a nice job but I make sure and keep boards in the middle of the unit so as not to run into issues around the edges of the oven.

It was non-trivial to convert an oven - and it makes the house lights flicker as I don’t think the oven is synced to AC Zero cross (not sure about that…). Perhaps Corvette123 can answer that?

Again - though - it is a great base platform to start with and I have been very happy with the solution over the two former ovens I had and my two hot plates. I am debating dropping a couple of grand on a used desktop reflow with conveyor or building another B&D IR or two and running them in tandem.

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blakec1:
I have never been happy with the skillet / hotplate. As an ME I just can’t reconcile how heat will travel through a fiberglass board with multiple heat contuctors (via’s and traces) and not have hot/cold spots.

I understand your reservations, but I've found it to work really well. What I do is carefully observe the process & apply more heat to the top using a heat gun in the areas that need it. This minimizes the overheating in the areas that heat up fastest. "Proper" reflow ovens actually have the problem you are worried about - in order to reflow the entire board, certain components will be overheated.

blakec1:
Basically they can get their lifespan cut significantly. Think of all the Mitsubishi TV’s or Escort Radar detectors that have died due to dead Electrolytics. CM’s will tell you that RoHS has significantly increased the problem due to the higher reflow temps.

Yes, the higher reflow temperatures are a problem, but IMO the problem is the electrolytics themselves. I try to avoid using them in my designs whenever possible, since I hate the idea of components that have an inbuilt finite life. With ceramic caps available in larger values at lower prices, it is often possible to completely eliminate electrolytics from a design.