SMTA David: What Is Measured During a Reflow Profile?

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SMTA David posted a question about reflow profiling, but it ... - Jun 25, 2019 by davef

The profile (temperature curve) is absolutely a function of... - Jun 25, 2019 by Steve Thomas

Thanks Thomas ... - Jun 26, 2019 by SMTA-David SMTA

I meant to ask before, what are you using to record the prof... - Jun 26, 2019 by Steve Thomas

davef

#82880

SMTA David: What Is Measured During a Reflow Profile? | 25 June, 2019

SMTA David posted a question about reflow profiling, but it was included in a question about an SMTA training course. I'm reposting it here in hopes of getting him a better response and because we haven't developed proper methods to communicate with SMTA ppl, but we will. Anyhow, David's question is:

Does the profile apply to both top and bottom heaters in each zone and should you use the same temp setting top and bottom in a zone?

Thanks

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Steve Thomas

#82883

SMTA David: What Is Measured During a Reflow Profile? | 25 June, 2019

The profile (temperature curve) is absolutely a function of both top and bottom zone settings as well as conveyor speed, blower speed, etc..

Certainly when you perform profiling you have to consider both top and bottom heaters when you make adjustments to generate the profile you want.

I can only think of one time that I deviated from top = bottom settings and I don't even remember why I did it. As far back as that was I suspect that it was a single sided, 63/37 board. Maybe it was warping due to an imbalance of copper and I was trying to reduce it, or I had issues with the board not wetting properly.....?

I only do limited profiling now (we're still trying to replace our last process engineer so I step in where needed) but haven't seen a need for this at all recently.

Frankly I would avoid it unless you come up with an issue that you feel can only be resolved with this, AND you can properly deal with the other problems it potentially presents.

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SMTA-David

#82889

SMTA David: What Is Measured During a Reflow Profile? | 26 June, 2019

Thanks Thomas

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