Reflow Oven Kit for VHS - TILT

[tdwebste]

I found this article on BGA rework stations. IR vs Hot air interesting.

http://xmoddz.com/choosing-bga-rework-station-hot-air-vs-ir

I have a colleague at work here who highly recommends IR for rework over Hot air, because it does not blow parts around. But has cautioned me about heating gradients and recommends both focused and area heating. He typically area heats from the bottom and focus heats from the top.

I will be reviewing semi manual pick and place rework stations which include cameras with him. But I expect the price to be significantly higher.

[iMakeRobots]

I just paid $185 to tilt it the rest of the way.

a) because loaning things to VHS makes me itchy.
b) because it’s a good fit for VHS and it already has a place it can live.

Thank you for being awesome supporting each other, VHS, and Marginally Clever Robots.

I like the idea of an off-the-shelf reflow more because it’s been tested by people with lots of experience and should have a warranty.

[ColinFitzgerald]

Hi all,

Just thought I’d chime in here as I have massive experience in SMT reflow methods (in a professional capacity)…

First off, DO NOT buy a cheap reflow oven from China or anywhere else: They are total garbage, and by that I mean they do not work at all. I had the unfortunate pleasure of trying to setup one for a client and it ended up in the dumpster, literally, I thew it there myself. It was $3,500.

SMT reflow with a normal, decent quality, toaster oven is super easy and doesn’t require a controller. I’ve reflowed hundreds of boards this way, with both leaded and lead-free paste. Large BGA’s are pretty tricky due to shadowing, but everything else works fine. The low temp Bismuth paste is crazy easy (can use a hair dryer…lol).

The trick is just profiling the oven. Usually I do 5 minutes of preheat at ~250F then crank to max for 2-3 min. The last bit is more critical but you can just watch it. Once you see the solder start to melt, count down 30 more seconds then turn it off. Simple as that. Let it cool down a bit before the next board. The two step, preheat then max is critical and the ‘secret’ to making this work.

The reason this works is because these little ovens don’t have much power. Their natural ramp up curve it pretty close to ideal. I’ve verified this on a few different models with profiling probes. For DIY work its great. There is no way a controller will improve it.

IMHO, the controllers are a total waste of money, for two reasons: First, it’s not needed. Second, there is just no way a temp control like this actually works. The temperature of the PCB and parts is very unrelated to air temperature, especially in something with such low thermal mass and power. Real IR/Convection reflow ovens DO NOT work like this at all. Real reflow ovens (that work), even the tiny ‘prototyping’ ones are 8kw or more. This kind of control is total nonsense.

Next time I’m in Vancouver I can do a demo. I also have a nice higher end toaster oven I can donate that I used to use for this. I now use a $35,000 VPS oven.

Please feel free to hit me up for any other info/advice re SMT. Most things are easy but the techniques are specialized and not always obvious.

Cheers!

Colin

[Janet]

Wow - thank you Dan. That’s awesome.

[iMakeRobots]

MFW I make something happen and someone steps in after the fact to make me feel stupid for trying. I am such a fragile snowflake.

[ColinFitzgerald]

Hey Dan,

Sorry for that, totally not my intent. I owe you a beer or equivalent!

FWIW, those funds could be used for all kinds of sweet SMT related gear.

I’m down for championing the oven itself, but I do need a partner to let me in and help set it up. I’m a new member and don’t even live in Vancouver, but work near the space a couple times a month.

Again, sorry for getting in late and raining on the original idea. Can we work together to get a sweet reflow setup in the space?

Colin

[iMakeRobots]

You don’t owe me anything. Make the space great, make great things at the space. That’s all I want.

I’ll open the space tomorrow @ ~3pm until late.

[mirong]

No, Dan, do not feel bad; you are awesome!

I have also contributed to the Tilt, and have no problem if it gets
slightly repurposed, since the end result will be much better.

[ColinFitzgerald]

Cool, that’s a deal.

I’m in Van again the weekend after next (Oct 22-23), so I’ll bring the oven and some other stuff.

Could a keyholder be available either of those days for 1-2 hours to let me in, and be present for a demo/workshop ?

Ideally a few other members are present for a quick workshop to do a knowledge transfer since I’m not around much. We could record it for the Wiki or something…

Afterwards, for those that are interested, I can explain in detail how SMT reflow works and some of the important tricks to getting it working really well (ramp rates, flux activation, double sided, ect…)

Cheers all !

[iMakeRobots]

the 23rd i’m scheduled to have an arduino class, provided there are sign-ups. 1-3pm. 3-4 could be the SMT talk & video. I’ll bring a GoPro.

[hectorh]

@ColinFitzgerald I live close to VHS and my schedule is very flexible. Let me know when, and I’ll come to the space to open it for you.

Thank you so much @iMakeRobots and @ColinFitzgerald

[Majicj]

Wow @iMakeRobots! Thanks for your generous donation! Also a big thank you to the other contributors as well!

@ColinFitzgerald

Hi all,

Just thought I’d chime in here as I have massive experience in SMT reflow methods (in a professional capacity)…

First off, DO NOT buy a cheap reflow oven from China or anywhere else:

Hi Colin:

Thank you for providing all this information. I agree with you on the above point!

SMT reflow with a normal, decent quality, toaster oven is super easy and doesn’t require a controller. I’ve reflowed hundreds of boards this way, with both leaded and lead-free paste. Large BGA’s are pretty tricky due to shadowing, but everything else works fine. The low temp Bismuth paste is crazy easy (can use a hair dryer…lol).

The trick is just profiling the oven. Usually I do 5 minutes of preheat at ~250F then crank to max for 2-3 min. The last bit is more critical but you can just watch it. Once you see the solder start to melt, count down 30 more seconds then turn it off. Simple as that. Let it cool down a bit before the next board. The two step, preheat then max is critical and the ‘secret’ to making this work.

Just a FYI. We currently have a Controlleo Reflow oven at VHS which I have successfully used for about 7 or 8 boards. Obviously I do not have your professional experience in reflowing. However I like it because it is dead simple to use. You put the board in the oven and hit the green button to start. That’s it. Everything else is taken care of for you.

No other actions are required on the users part. This is an ideal level interaction for folks who are new to reflow soldering. No mentions of profiling, timing and temperatures etc are required. There is nothing to intimidate newbies.

Anyways as I originally promised I will not be purchasing anything from the tilt funds until we get consensus on the best approach for VHS.

I am looking forward to a discussion on what is best for VHS considering the following

1. Effectiveness in successfully reflowing boards (does it work?)
2. Ease of use / training for complete beginners
3. Cost

Whatever we decide I want put this into motion by Monday October 24th. That gives everyone two weeks to discuss our options and reach consensus. This also gives Colin time to do a presentation.

Best

Mark

[Majicj]

@ColinFitzgerald

Cool, that’s a deal.

I’m in Van again the weekend after next (Oct 22-23), so I’ll bring the oven and some other stuff.

Could a keyholder be available either of those days for 1-2 hours to let me in, and be present for a demo/workshop ?

Ideally a few other members are present for a quick workshop to do a knowledge transfer since I’m not around much. We could record it for the Wiki or something…

Cheers all !

Hi Colin:

Does this Sunday Oct 23 - 3-4pm work for this demo/workshop?

Thanks

Mark

[Majicj]

I have requested that Tilt refunded the Reflow Oven tilt funds to contributors. You should have your refunds sometime this coming week.

I’d been trying to get banking info setup for VHS and was not getting the required info.

I have $90 from myself and Tom. For the remaining tilt contributors your contributions would still be appreciated if possible by Etransfer or cash. I’ll contact you all privately,

best

Mark

[packetbob]

I have completed the VHS SMD Reflow Oven and intend to bring it to the Space on Tuesday… Or tomorrow if I get a chance…

Many thanks for the $$ and patience of all who donated to this project…

[Majicj]

@packetbob

I have completed the VHS SMD Reflow Oven and intend to bring it to the Space on Tuesday… Or tomorrow if I get a chance…

Many thanks for the $$ and patience of all who donated to this project…

Woooo Hooo! Can’t wait to try it out! Thank you for all your work in putting this together!

[Janet]

Thanks @packetbob - you are a wonder! And thanks for the loaner oven which
many of us have used. It’s given me my intro to stencilpaste/over reflow
work - super fun!

[SteveRoy]

Awesome, you do high quality work. A great asset for VHS

[Jarrett]

A VHS success story. Awesome work!

[Majicj]

Shoutout to @TomKeddie for the seed money to start this project that he raised via his VHS SMD workshops and also to @iMakeRobots ++, @mirong and @lukecyca for their contributions to the Tilt. Total $'s raised for this project was $325.

And of course non of this would have happened without @packetbob and his awesome build!

You guys rock!

Looking forward to cooking some boards!