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Reflow oven exhaust down

Views: 3328

#53545

Reflow oven exhaust down | 4 February, 2008

I just discovered my reflow oven exhaust had no suction and I'm fixing it now.

What I want to know is what happened to my process.

FYI. The exhaust from my other oven was getting kicked back into the faulty oven because of this loss of suction. The working oven has its own built in exhaust fan where as teh faulty one relies entirely on suction from an outside source.

I imagine the temperatures in the oven became hotter than the profile was set for? I can't run a profiler through right now either because its out for calibration.

What kind of damage did the faulty oven cause that I am unaware of?

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#53546

Reflow oven exhaust down | 4 February, 2008

Your oven no doubt compensated by reducing energy to your heaters so it might not be as bad as you think. I'd be more concerned about even heating than over heating. My opinion is that an out of calibration profiler result is better than no result at all. I'd run it, note that it's out of cal., and deal with the consequences later (if it's not at the cal. lab, that is). You need to know what the temperatures are in that oven when the blower's not running to know if your product is suspect or not. Then it's up to your procedures and quality standards to determine what you do with the product.

You should run a profile on the other oven as well, under the same circumstances.

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#53547

Reflow oven exhaust down | 4 February, 2008

Well the profiler IS out for calibration so I can't use it.

However, what piqued my curiosity is your statement concerning uneven heating. On the product we were running we had several non-liquidous solderjoints where as the rest of the joints looked ideal.

It would seem you are spot-on about the un-even temperature.

Hope that profiler gets here today.

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#53580

Reflow oven exhaust down | 6 February, 2008

We had a vent block up not too long ago ourselves. Saw multiple solderjoints, especially on fine pitch micros, that looked like they had alligator toes. We solder bump, so it was obvious that area didn't get hot enough to liquify the solder and have it wick back up the leads. We now have a bi-monthly PM to check the vents.

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#53590

Reflow oven exhaust down | 7 February, 2008

Bi monthly?!!? What are your exhausts getting clogged with? You have that much dust in the air that cleaning every two weeks is necessary?

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#53614

Reflow oven exhaust down | 11 February, 2008

The solder problems that were created caused overcompensation. Plus our PM schedules could be monthly, could be yearly depending on the maintenance crew for a particular line.

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#53617

Reflow oven exhaust down | 12 February, 2008

Without forced exhaust your oven will struggle to regulate zone temps, especially if a cooler one next to a hotter one. There should be no damage to the oven, just working harder to regulate itself.

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