Tips When Moving a Reflow Oven

Phil
Welcome to Board Talk with Phil Zarrow and Jim Hall, the Assembly Brothers, who by day go as ITM Consulting.  Let's see, what kind of subject do we have to warm up to today Jim?

Jim
One near and dear to my heart, reflow. This comes from Q.N. After moving a reflow oven to a different site, what steps do you need to perform on the machine and the heat exhaust in order for the machine to be certified?

Phil
Certified? Is there an official reflow oven certification? Oh yeah, that's right. That's us. 

Jim
Right, there is no known certification standard for ovens. But certainly you do want to make sure that your oven is performing in the same manner in terms of accuracy and repeatability that it did at the former site. The most important thing that's more likely to give you problems is the conveyor system.

This is what carries the board. You only have your little edge conveyors.  Getting the machine leveled, getting them lined up, vibration free, parallel and so forth so that you don't drop boards or jam boards in your oven, is probably the most important step.

That being said, you want to get the same thermal performance. You want to get the same repeatable profiles on your board. You are very astute to ask about exhaust because proper exhausting can affect the performance of an oven. So you want to make sure that the exhaust is set up with whatever measurements you use to set it up initially.

Once it's set up you want to take some calibration vehicle that you have history on, ideally both a profile and repeatability of that profile, and run it again. And run multiple profiles to make sure that you're getting accuracy, getting the same peak temperatures, the same time above liquidus, slopes and so forth, and that profile is repeatable over multiple profiles so that you can get the same performance and get the same quality boards that you were getting.

Phil
You might also check with the oven manufacturer and see if they have any other recommendations in addition to maintenance. Generally they probably have some experience and know where the vulnerable spots are.

But anyway, that's enough for our fragile egos. Be careful with that reflow oven.  And when you're using it, whatever you do -

Jim
Don't solder like my brother.

Phil
Yeah, and don't solder like my brother.

There should be no issues with moving a reflow oven as long as you don’t drop it and have the same utilities in both places. Pressures, lip vent draw, nitrogen quality, and drafts from AC units, open doors etc. You should check rail parallelism to make sure something hasn’t moved, but you should do that during regular maintenance intervals anyway. Speaking of regular maintenance.. you should also confirm all profiles. If they changed get help because something is messed up.

Insure all facility inputs are identical or adjust accordingly ie power, air,N2, exhaust etc Common mistake is not having the same balanced exhaust at the new location. This can greatly affect performance especially in an inert atmosphere.

I have seen some new reflow ovens that have "travelled" a lot from one side to the other inside the factory with worse inner atmosphere quality than an old oven that stay all its life at the same place. Take care when you lift and move your reflow oven because loosing some paralelism new air entrances will be created and then you have a lot of extra work to decrease the residual oxygen level in reflow zones. As a consequence it will be necessary more nitrogen than before to reach your receipe (N2 to decrease the residual oxygen level at reflow zones).