WTB(UK): CONVEYOR REFLOW OVEN, SINGLE PHASE.

[trev]

Hi. Anyone know of a single phase, 3 done reflow oven for sale?

Trev

[phonoplug]

By single phase do you mean 13A plug or potentially 30-40A single phase?

[trev]

That is a good question. I think 13A really. It is only for small prototyping batches of 10 or 20 boards. I am not wanting to go into any kind of full production. I just want to get a good heat profile.

Trev

[Gopher]

I don't think they're all that common, even the small vapor phase units seems to default to 3-phase. Blundell  & PMTech sell the Mistral 260 which is single phase so tracking down one of those could be a plan- @£8k new that's about the same money as often seems to be asked for 2nd user VP reflow. Turner Electronics http://www.turnerelectronics.co.uk/products/surface-mount/reflow-solderin/ have a bunch of small ovens of which the tabletop DDM seems to single phase at the very least.

I don't think I've ever seen any of these crop up on eBay or Grove for instance, but maybe if you had a chat they might be able to hook you up with a unit as someone upgrades or an ex-demo...

3 zones does work for many people, but combine that with a short process length and low power and you'll struggle to get a "good" profile on some board types. What those issues will be will depend on the type of oven, and the components used. IR for instance has shadowing issues with tall parts as well as some degree of colour sensitivity , VP is not electrolytic friendly (personally I question the value of surface mount electrolytics in small batch manufacturing) and small convection ovens may simply not be able to deliver the requisite heat for a dense PCB. 5-6 zones and 2.5m+ process length is where you can start to be pretty confident of being able to come up with a nice profile for just about anything, extra length and zones after that is all about delivering a decent profile while also improving throughput.

[Mike]

https://www.ebay.co.uk/itm/Gastrotek-conveyor-toaster-hardly-used/222760925067?hash=item33dd95f78b:g:x9gAAOSwySlaOCiM

[trev]

Well it does depend on the size of the board and what is on it. That is for sure.

Toaster oven looks interesting, Mike but not sure how even the temperature across a board would be .

VP I like the look of and electrolytics would not be a problem. Hand soldering for small batches is no problem. I am not looking to go into production in any serious way. With VP though its going to be the setup costs that potentially make it out of reach. I am not looking to spend 1000s on a reflow. I was hoping 100s really tops.

[trev]

https://www.ebay.co.uk/itm/Gastrotek-conveyor-toaster-hardly-used/222760925067?hash=item33dd95f78b:g:x9gAAOSwySlaOCiM

It is interesting that they do have a conveyor belt on those toaster ovens. That could be programmed to bring the board out of the heat once done I think. For the money they might be worth playing around with.

[phonoplug]

That Ebay link - isn't that an actual bread toaster? You'd have to watch out for your board being dropped out the other end upside down and all the parts falling off!

Seriously though, I did start out using a drawer oven and found that the parts used to get darkened noticeably in the process. It was improved by running the cycle with the drawer ajar which helped the smoke escape and therefore the darkening of components, but still it wasn't great. First run was always different to second because subsequent runs the oven was pre-heated which made a massive difference. I haven't used it for a long time now.

If you're not in a hurry keep an eye on Ebay. 13A ones come up occasionally but they aren't overly common. I know someone who used to have one and it worked well for them, but then their boards tended to only contain small parts, be no more than 2 layers and always 1.6mm. Certainly no magnetics of any size. Not sure what the heat up time was like.

[Mike]

Only a semi-serious suggestion but might be worth a try, with suitable adaptions to conveyer, speed, power etc.
Whenever I see one in a sandwich shop I'm reminded of how much they look like a small reflow oven!