Survey of Single Phase Reflow Ovens

[forrestc]

So, we're a couple weeks out from (finally) actually having enough power in the manufacturing facility to be able to upgrade our oven.   We're currently using a Neoden IN6, which is working fine, except we seem to be burning out the Zone 3 elements with more frequency than I would like.  Plus, the recovery time can be an issue for heavier boards.       I've used a few others before this, but that is irrelevant to the discussion at large.

As I don't have three phase power, I'm limited in the ovens I can consider to those that either run natively on 120 or 240V single phase power, or which can be easily re-wired to do so.   Amperage isn't a huge deal up to a certain point.

As I figure my power situation describes many of the users of this forum (that is, no three phase power), the thought occurred to me that while I'm surveying the landscape, I should build a spreadsheet of ALL of the commerical oven options that can be powered by single phase power and try to capture the common differences between them - and then post the results back here (and hopefully keep it somewhat up to date).   I'm obviously interested in something conveyored and probably something cable of a couple hundred boards per day, but I'm also planning on including the T962's of the world as well.

So the point of this topic is to gather a list of all of the smaller, single-phase, reflow ovens that everyone knows about.  I was going to start with a list I already knew about, but I think I'd rather just let everyone post the ones they know about.   And, if there's something non-obvious about the oven when I start digging through datasheets, then that would be useful too.  That is, something like "can be easily rewired to use single phase" or "doesn't have cold junction compensation" or something like that...   Not sure how this will all end up in the spreadsheet, but I figure I can get started and then post as I go.

Thanks to everyone who is willing to help out here...

[Pinkus]

OK, I will start with the three ovens I had (still have the T-937):

CIF FT-02
· desktop oven, well build.
· You can throw out the 2x1000 Watt elements and replace by 2x 1500 Watt which gives better results.
· Terrible interface/software, works much better after throwing away their board and software and installing a separate oven controller.

T-962
· desktop oven
· no good soldering results, also results not reliable.
· not worth the money

T-937
· large desktop oven suitable for whole panels
· larger brother of the T-962 but with better build quality and much better soldering results.
· Includes computer interface for direct drive or uploading individual profiles.
· The best choice of these three ovens

Edit: you should know that with all these desktop ovens, you will need some time to cool down the unit after soldering a board. Calculate with approx. 15 minutes in total for one run (heat-up, reflow, cool down). You may remove the PCBs earlier but the unit needs to cool down to almost ambient temperature.
And: make sure you have a fume outlet and a fresh air inlet in your wall nearby.

[sam512bb]

Good day,

 I have a Puhui T-961 and I am pretty happy with it.  I ordered direct from Puhui and they were great to deal with and support, although not much was needed over the 8 years I have had the unit.  When I first got the unit the conveyor speed control was not working properly, and Puhui promptly Fed Ex'd a replacement.  Recently, I had two SSR's fail along with and the 2 top exhaust fans.  The SSRs and fans are standard and so I purchased replacements from Digikey/mouser without issue.  The replacements are not inexpensive, but they are quality industrial and known brand parts unlike the originals.  That said after 8 years and lots of use, it is to be expected.  The unit was setup for 3-phase power, but could easily be re-wired for single phase and a larger current load circuit...which is what I did.  Startup time to reach temp is about 12-15 minutes.

Having used it for some time, I think the only drawback is time/effort profiling the oven to meet/match the various solder profiles needed.  The 3 up and  2 down heating zones are OK, but I think more heating zones would help in fine tuning the solder profiles along with a slightly longer length.    Even so, the oven has worked well for me for 2 Layer boards (top/bottom placements) along with heavy copper PCBs, and even 4L fine pitch BGA parts and with top/bottom placements. 

Cheers,

Sam

[dkonigs]

I'm personally still using the "converted toaster oven" approach, based on the Controleo3 controller and reference design.

I went with it because it runs off 120VAC, and because I really did not want a T-962 (the whole IR heating, plus needing a dozen mods to not suck, just rubbed me the wrong way).

I really wish I knew of more "batch" style options that would be viable for my use case, specifically in the <$4k price range, but I keep struggling to find any.  The best I've come across in my research attempts are the LPKF ProtoFlow series, though I don't really know how good those are.  Also, I'd probably need to get a 220V outlet wired up to use one.

[Doctorandus_P]

If you've already got an IN6, then a toaster oven is not going to be an upgrade.

[forrestc]

If you've already got an IN6, then a toaster oven is not going to be an upgrade.

It might be more reliable.

We only get a few months out of the zone 3 elements at this point.   All of them have failed in the same way - with the nichrome (or similar) heating wire vaporizing.

[Doctorandus_P]

We only get a few months out of the zone 3 elements at this point.   All of them have failed in the same way - with the nichrome (or similar) heating wire vaporizing.

That's a real annoyance. I do not know what those elements look like. Maybe it is an option to refurbish a used element with some different wire.

In ovens for potting or heat treatment of steel, the wire is considered a consumable, but those ovens also get much hotter. Thicker wire is more robust and lasts longer, but you also have to use more length of it because of it's lower resistance. Using even more wire will decrease the power of the heating element a bit further and lower it's temperature which may also help with keeping it intact longer.

[forrestc]

That's a real annoyance. I do not know what those elements look like. Maybe it is an option to refurbish a used element with some different wire.

I've looked at this and haven't seen a reliable way to either do this or possibly fix the ones which keep burning out.  They sort of embed this wire in some sort of high temperature white glue stuff that flakes and then embeds all of this between some aluminum plates.   The burnout tends to be where the metal isn't near the plates.

At $600 delivered, each, I'm kinda motivated to either figure out how to fix these in-house, OR switch to another oven.

[forrestc]

Figured I'd share what I had so far, for those of you who can view google docs.

It's still very much a work in progress, and I need to fill in holes where I can.

https://docs.google.com/spreadsheets/d/1tIwnTBt4pOaDvgcw82zICtrGg5a3lDscmnBiiCTgCuQ/edit?usp=sharing

There are a couple ovens that I came across which are 240/380 three phase that I have reason to believe may actually work on 240V with some minor rewiring.  I'll try to check with the vendors.

If anyone knows of a vendor or ovens that I missed, let me know.

[dkonigs]

Figured I'd share what I had so far, for those of you who can view google docs.

It's still very much a work in progress, and I need to fill in holes where I can.

Ahh yes, that list reminds me of the DDM Novastar ovens, particularly the GF-C2-HT.  I have absolutely no idea if its any good, or even what it really costs (price isn't listed directly, and different suppliers have posted quite different pricing).  But it has piqued my interest before.

It might be useful if the spreadsheet could also list the best known pricetag for these various ovens, since that information often seems to be quite hard to publicly track down.  (and its not uncommon to see forum posts where people think they're a lot cheaper than they actually seem to be.)

[Kean]

That's a real annoyance. I do not know what those elements look like. Maybe it is an option to refurbish a used element with some different wire.

I've looked at this and haven't seen a reliable way to either do this or possibly fix the ones which keep burning out.  They sort of embed this wire in some sort of high temperature white glue stuff that flakes and then embeds all of this between some aluminum plates.   The burnout tends to be where the metal isn't near the plates.

At $600 delivered, each, I'm kinda motivated to either figure out how to fix these in-house, OR switch to another oven.

I've been considering an IN6 but have heard similar reports of elements burning out, and also having earth leakage problems when cold.  My usage would likely be only a couple of days a month.

Out of interest, do you have a rough idea of the operating hours you are getting from the elements before failure?  And I presume you are running a lead free profile?

[forrestc]

I've been considering an IN6 but have heard similar reports of elements burning out, and also having earth leakage problems when cold.  My usage would likely be only a couple of days a month.

Out of interest, do you have a rough idea of the operating hours you are getting from the elements before failure?  And I presume you are running a lead free profile?

Don't have the IN6 on a GFCI so not sure about the leakage issue....

Yes, we're running SAC305 at 280 top and bottom in the final zone.   I'm guessing we run the oven 2-3 days a week on average for 8-10 hours/day.   

Now I've complained about how many elements I've lost, I looked back through our logs, and the last time we lost one appears to be back in February.  But in 2021 we lost at least 4.  So I guess it's getting better instead of worse.   The last couple have had a bit different design, but apparently they do still fail.   The other thing we did which might have helped is to back that zone 3 temperature down and slowed down the conveyor to compensate.

[SMTech]

I've been considering an IN6 but have heard similar reports of elements burning out, and also having earth leakage problems when cold.  My usage would likely be only a couple of days a month.

Out of interest, do you have a rough idea of the operating hours you are getting from the elements before failure?  And I presume you are running a lead free profile?

Don't have the IN6 on a GFCI so not sure about the leakage issue....

Yes, we're running SAC305 at 280 top and bottom in the final zone.   I'm guessing we run the oven 2-3 days a week on average for 8-10 hours/day.   

Now I've complained about how many elements I've lost, I looked back through our logs, and the last time we lost one appears to be back in February.  But in 2021 we lost at least 4.  So I guess it's getting better instead of worse.   The last couple have had a bit different design, but apparently they do still fail.   The other thing we did which might have helped is to back that zone 3 temperature down and slowed down the conveyor to compensate.

For comparison, our massive (relatively, its small for a commercial oven) 7 zone, 3phase Heller runs the final zone at 255 for many profiles and I could easily run it lower still should that be needed. This greatly lowers the risk of overheating something as most parts can handle 260 for short periods during reflow.

[Styno]

We're still using our Essemtec RO06 drawer oven for lead free prototyping and small series. It works good enough even with A4-size panels but you need to make sure to use the rotation that gives the least IR-shadow when using taller components. The configuration is bares-bones: idle temperature, soak temperature/time and reflow temperature/time, there are no ramp-up/down speed settings. You can store a few configurations for e.g. single pcb, normal panel and high mass panel. We needed to install a softstarter or slow circuit breaker because the inrush current when cold would frequently trip the regular 16A breaker. Bake cycle for a normal panel takes around 12 minutes including cooling to idle temperature (110 degC)

RO06 manual

[mairo]

I have Neoden IN6, Eurocircuits eC-reflow mate, LPKF ProflowS and a toaster oven without a dictated controller. For reliability and ease of use I will pick any of the 3 non conveyor units any day.

[seon]

My IN6 has also been problematic since day 1 - I've had all elements replaced once, and the zone 3 top and bottom replaced an additional 2 times each, and some days I can get it to reflow fine and others, the top zone 3 element wont get to temperature. I get the earth leakage issue on super cold days ion the machine has been idle for more than 2-3 days. PITA.

I was looking at the IN12 before Neoden decided to not fix my PnP - but that situation has evolved since it was discussed a few weeks back (though not quite there yet - I'll update everyone "soon") - so I might look at the IN12 again - the chain version, not the mesh one. I need chain to be able to also use my PCB re-stacker.  My goal is a fully automated line from start to finish.

I have 3-phase here specifically installed for a new oven to replace the IN6 - unfortunately it's hard to find a good and intuitive to use 5-6 zone 3 phase oven that isn't either too long for my space requirements (most are 3.2m + in length) or that don't cost a left kidney (looking at you Essemtec and Heller).... so though the IN12 is only single phase, it's shorter than the other options and it has the 6 top and 6 bottom elements, so there's a lot more control and granularity compared with the IN6...  but might also be as bad with the element breakdowns.

Cheers,

Seon
Unexpected Maker