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Replacement for nitrogen in the reflow oven

#28717

Replacement for nitrogen in the reflow oven | 21 May, 2004

We have been using nitrogen in our reflow ovens for many years to reduce oxidation on our solder joints. Management is concerned about the high cost of nitrogen and have suggested we use hydrogen instead. I'm not sure if this is a good idea, but we can get hydrogen so much cheaper then nitrogen that I don't think I am going to have much say in the matter. What are your opinions?

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Grant Petty

#28719

Replacement for nitrogen in the reflow oven | 21 May, 2004

Hi,

This would be a very exciting idea. Nitrogen is an inert gas, so this is why it's used, however Hydrogen mixed with oxygen in normal air is highly explosive, so it would be one of the worst gasses to use in a reflow oven I would think. Remember the Hindenburg!

Nitrogen is one of many inert gasses, and if you look at a periodical table you can see all the inert gasses in a column under Nitrogen. It's been a long time since high school chem. class though.

However Nitrogen is about 78% of the atmosphere (I think that percentage is close) so it's a very easy gas to get, because most of the air you breath is Nitrogen. So it's really going to be the lowest cost inert gas you can get.

Are you getting it bottled, or are you using a nitrogen generator?

Regards,

Grant Blackmagic Design

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#28734

Replacement for nitrogen in the reflow oven | 24 May, 2004

call me picky but doesn't hydrogen combust? maybe soemthing you could do is look at your process and your products and decide if you actually need to run in N2. Yes ok I can hear the crys now but seriously, for the vast majority of things if you have good process control and obviously you do!? then selecting a good paste that runs in air, and there are a few, would let you switch it off. Now I agree that there are products where you really want it there and yes it will open your process window but time to think about cost vs return. The other thing is to look at the ppm levels yoru chasing, soem say 50ppm, soem 100 some 500 and so on. On most things you will hapily get away with 500ppm and still ahve a wider process window but reduced cost. Another thing to remember is that now all ovens are created equal, you need to look at the machine your using vs the rest of the market. I'm generalising here but from my own experience I tend to find that US machine manufacturers care less about how much N2 their machines use than European ones due to the cost of N2 in the US compared to the rest of the world. Other option perhaps is look at a nitrogen generation plant?

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blnorman

#28742

Replacement for nitrogen in the reflow oven | 24 May, 2004

As stated above, Hydrogen is EXPLOSIVE, very bad idea. Management might have meant HELIUM, also inert.

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#28747

Replacement for nitrogen in the reflow oven | 24 May, 2004

Maybe here's an opportunity to get a new oven. Electrovert, BTU and Vitronics offer closed-loop N2 control as an option. This, together with other improvements on oven design can reduce N2 consumption by as much as 40%. Not to mention reductions in electrical consumption too. Electrovert's new OmniEXCEL oven, for example consumes about 50% less electricity than the previous OmniFlo models. Ovens are improving performance in reduced utilities consumption and better at thermal transfer efficiency.

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#28782

Replacement for nitrogen in the reflow oven | 26 May, 2004

Let's not be hasty about the BTU, the Pyramax consums even more N2 than the Paragon that it replaced by something like another 40%! and the Electrovert aint that much better although it's been a while since I looked at them.

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#28795

Replacement for nitrogen in the reflow oven | 26 May, 2004

Electrovert has hard data on electrical and N2 consumption for the new OmniEXCEL series ovens to compare with preceeding OmniFlo series. Have a look.

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Ken

#28800

Replacement for nitrogen in the reflow oven | 26 May, 2004

Helium is even more expensive than Nitrogen. How about Argon?

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#28823

Replacement for nitrogen in the reflow oven | 27 May, 2004

Im not an expert at this, but im going to have to agree with blnorman. I wouldn't use Hydrogen, its very explosive. I would look into a considering a new oven to cut back on cost. Yes you will have to put out the money for a new unit, but if it reduces the operation cost, it will pay for itself after some time.

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James

#28828

Replacement for nitrogen in the reflow oven | 28 May, 2004

Check out this site for on-site N2 generation. www.onsitegas.us

James

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blnorman

#28830

Replacement for nitrogen in the reflow oven | 28 May, 2004

I'd guess any noble gas would be expensive.

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