SparkFun Forums

[netwarrior]

I am sourcing for a bench-top reflow oven for my small workshop as I am doing some SMT work in my spare time. Currently I hand solder all the smt components using the soldering iron. This method not only time consuming, it has many limitation and not possible to perform on certain packaging.

After much thought, I am seriously consider getting a reflow oven with my bonus so that I can solder packages like QFN or some tiny compoents.

I found these two models on the web: GF-12HC and GF-B, both from APS Novastar LLC (http://www.apsgold.com/reflow.htm). They look interesting to me. However, as I have never own a reflow oven before, I have no ideas on what spec to look for when selecting a reflow oven.

I understand reflow oven is expensive and I would to avoid making a wrong purchase.

Appreciate if experienced user can share some thought in selecting a reflow oven.

Thanks

[theatrus]

I'd first practice with a toaster oven (or skillet). I know it sounds hokey, but it works great. It will let you practice with paste or other methods of soldering using reflow. After a few runs, you'll have an idea if you need a real oven and will have gained more knowledge about the whole process.

[silic0re]

I second the toaster oven, too. I just populated my first board with a toaster oven (because of leadless QFN's), and I have to say, it was amazingly fast and looks beautiful! Normally I dab solder paste on pins, then hand solder them, but with the toaster oven I just had to dab paste everywhere, squish the parts into the paste, and bake. 5 minutes later, a populated board comes out that looks fantastic!

I'm just using a normal toaster oven (very inexpensive), but some folks use the toaster oven reflow controller that SF sells, which I think can be had for around ~$100 and gives the oven a precise reflow profile. For what its worth, I'm not sure my toaster oven is even capable of ramping up as fast as a normal reflow oven, so I just set it to max (~250°C), turn it on, and in about 5 minutes the paste reflows.

Very fun! I would totally recommend giving it a try!

[jandirks]

This could be an interesting read: http://www.rcgroups.com/forums/showthread.php?t=911539

[netwarrior]

Thanks all for the advice and link. I'll give it a try using my old toaster while doing some research on the reflow oven.
Other than supporting my hobby, I'm also planning to use the reflow oven to make some pocket money by helping other hobbyist in assembly their board. I know it can't bring in big money, but at least it helps to pay part of the equipment and components bills.

[snarfer]

This blog might be relevant. This is not mine and I don't necessarily agree, just something I came across recently: http://audio.peufeu.com/node/69

Personally I have had excellent results using (1) my girlfriend's clothes iron and (2) an old aluminum heatsink sitting on top of my electric range.

Also I highly recommend getting a kapton stencil from Ohararp.com. Saves lots of time. Well worth the $25 plus postage.

[ohararp]

So I have put together many a board using both the hot plate an toaster oven methods. I have found that the temp reflow control is jut overkill and not worth the trouble. I have a $60 oven from Target that works great! It even has a glass window in the top so that I can look down on the boards and see that they have reflowed.

I recommend setting your oven to about 200F and letting it stabilize there. When your board is ready raise the temperature to 400-450F (you'll need to figure this out exactly for your setup) and place the board in the oven. Watch to see when your board is reflowed (1-3 minutes), when it has flowed open the door and slide the rack out allowing your board to cool. If you are quick you can even move parts around in case they are not properly aligned.

Overall, smt reflowing is not rocket science, and most smt parts are very robust. Now, I wouldn't recommend a setup like this for production quantities but for prototypes and diy work it is totally legit.

Save yourself some money and don't buy the fancy reflow oven or controller.

[funnynypd]

It even has a glass window in the top so that I can look down on the boards and see that they have reflowed.

Wouldn't it be better to add some heat shield on most part of the glass to help the oven temp increase in a even faster step? And only leave a small space as a watch-window.

Just a thought. I saw people using some shiny metal sheet on the class to help reducing heat loss just as the the rest of the five oven walls.

[rpcelectronics]

+1 for the skillet method!

Its the only way that I bake SMT jobs now in-house.

[funnynypd]

What makes you preferred the skillet instead of the toast oven?
Skillet is not good for double side SMD PCB.

[rpcelectronics]

What makes you preferred the skillet instead of the toast oven?
Skillet is not good for double side SMD PCB.

Good point. I don't typcally work with two sided SMT boards, so I have not run into that yet.

My main reason for going with the skillet is, I like the fact that the heat is concentrated on the bottom side of the board and the heat can't easily do damage to any plastic parts.

Good example. I have a battery charger that I am currently selling that has a single white plastic SMT connector for the battery. When I "fry" them at home in the skillet, the connector remains as is. I had a contract house do a big batch for me recently and I noticed that the reflow oven method actually turned the connectors a shade of brown. Not a big deal in this application, but I do like keeping the heat where I need it.

[funnynypd]

So I have put together many a board using both the hot plate an toaster oven methods. I have found that the temp reflow control is jut overkill and not worth the trouble.

Agree. It is amazing how those appliance working on reflowing the PCB just like the super-expensive industry ovens.

One Cons is: you have to stay there and watch the solder reflow. It is not a issue for hobby purpose at all.