How to identify any Vibration Source in Reflow Oven

#83136

How to identify any Vibration Source in Reflow Oven | 2 August, 2019

Hi Team,

Please help me out with ideas . How to verify the vibration in reflow oven.

Regards, Ameen

#83140

How to identify any Vibration Source in Reflow Oven | 2 August, 2019

A recording accelerometer is about the only thing I can think of. Unless you can find an insulative container (like for a profiler) you'd just have to run it through a cold oven.

Alexey

#83162

How to identify any Vibration Source in Reflow Oven | 3 August, 2019

There are no many moving parts in oven. Usially fan can give some vibration. Every heating zone have fan, so you can turn off them one by one and check vibration.

#83173

How to identify any Vibration Source in Reflow Oven | 5 August, 2019

In my experience the largest contributor to vibration or other abnormal product movement in a reflow oven is deferred maintenance of a chain mesh belt conveyor.

Travis H

#83174

How to identify any Vibration Source in Reflow Oven | 5 August, 2019

We have a Rehm oven that can vibrate hard enough to shift parts on the board. The vibration is due to flux build up on the exhaust blower. If we don't clean it regularly we start to see parts shifting in the oven.

Justin M

#83179

How to identify any Vibration Source in Reflow Oven | 6 August, 2019

Can you possibly elaborate on your problem and why you think you have an unidentifiable vibration?

#83189

How to identify any Vibration Source in Reflow Oven | 7 August, 2019

Hi Thanks All,

In one of our reflow oven , component skew after reflow.

So we are suspecting the vibration in the oven.

But not able to get the exact source of vibration.

So please help us out.

Regards, Ameen

#83190

How to identify any Vibration Source in Reflow Oven | 7 August, 2019

Hi Steve,

thanks.

please suggest me any supplier who can provide us accelerometer for reflow oven.

Regards, Ameen

Justin M

#83196

How to identify any Vibration Source in Reflow Oven | 7 August, 2019

It takes a good deal of sudden movement to skew parts. Who makes the oven?

#83197

How to identify any Vibration Source in Reflow Oven | 7 August, 2019

I hesitate to recommend anyone as a good source just because I haven't personally investigated it myself.

There are several manufacturers of recording accelerometers....I just looked at Google and found a couple that I might call on if I was looking into it myself. What I don't know is what you need to specify for specifications to best serve your purpose. You might want to read this:

https://www.ni.com/en-us/innovations/white-papers/06/measuring-vibration-with-accelerometers.html

just to get some more background.

Ideally you'll find one that either fits into your profiler enclosure (although that would dampen the shock and/or vibration that you're trying to measure) so you can run it hot. Otherwise, you'll have to run it without heating it up, which could change the values of the very characteristic that you're trying to measure.

It's possible that there is a high temperature tolerant device that's made for specific industries, but I didn't come across one.

One thing to consider first, though, is Justin's comment. A high frequency low amplitude vibration is probably going to do more to center parts than anything else, so what you're looking for is intermittent shock that affects the operation of the conveyor. At least some of that should be visible just by watching it.

charliem

#83198

How to identify any Vibration Source in Reflow Oven | 7 August, 2019

The melting of the solder during reflow itself can center up or skew a component. This could be pad size differential, incorrect pad size, unequal solder deposition amounts, pad spacing in reference to component size just to name a few.

#83200

How to identify any Vibration Source in Reflow Oven | 7 August, 2019

He did mention that it was limited to one oven, so it seems that at the very least the process window is reduced in that oven.

Justin M

#83207

How to identify any Vibration Source in Reflow Oven | 7 August, 2019

Which make and model oven do you have? In my past life, I had a problem with Hellers where what I think was called a clutch assembly would slip. As part of the PM on those ovens, we had to tighten that clutch assembly. If we didn't, the belt and edge support chains would jump occasionally. That would be enough to cause skew..

davef

#83208

How to identify any Vibration Source in Reflow Oven | 7 August, 2019

I agree with Chariem.

Take a look at this thread [posted by the same author as this thread] on SMTnet: Component Skew during Reflow Process [ https://smtnet.com/Forums/index.cfm?fuseaction=view_thread&CFApp=1&Thread_ID=22131&mc=7 ]

The pads on this board don't seem to match well with the component terminations AND there's too much solder on the board!!! ... A textbook prescription for component slewing, eh?

#83219

How to identify any Vibration Source in Reflow Oven | 8 August, 2019

Thanks a lot everyone.

For the valuable knowledge sharing.

And technical links. ( will go through it )

We have BTU oven ( Pyramax X 150N ).

Regards, Ameen

SMTA-Ray

#83227

How to identify any Vibration Source in Reflow Oven | 8 August, 2019

Sorry but I disagree The conveyor be it mesh belt or pin chain is a moving part that has caused many parts to dislodge Lack of lubricant on all the moving parts is usually the culprit I’ve also occasionally seen a bent link on a mesh belt snag & hook on something then let go like a sling shot

This message was posted via the Electronics Forum @ SMTA SMTA

sssamw

#83230

How to identify any Vibration Source in Reflow Oven | 8 August, 2019

What is the skewed part ? How you exclude other causes?

#83232

How to identify any Vibration Source in Reflow Oven | 8 August, 2019

Hi Sam,

The skewed part images I have shared at my first Query.

We have excluded other causes because, We have faced this issue in one particular oven. Where as this is running for many years in other oven lines and we don't have this issue.

So other chances are excluded.

Regards, Ameen

#83233

How to identify any Vibration Source in Reflow Oven | 8 August, 2019

Hi SMTA Team,

Thanks for the input.

Will consider the point and re verify lubrication in our maintenance activity.

Regards, Ameen

Dr. Aaron Hutzler

#86283

How to identify any Vibration Source in Reflow Oven | 17 February, 2021

Dear Ameen,

we are providing a profiler for vibration during reflow: https://ah-mt.com/the-omnibus/

Aaron

JCsync40

#86291

How to identify any Vibration Source in Reflow Oven | 20 February, 2021

Hello Ameen,

It is needed a moderate impact bump to generate skew. Even blowing of the fans generally cannot generate serious skew -unless the pads apertures are not suitable for the components size/weight. You can try for yourself. Take a board with your hands with the componentes placed on the solderpaste just before reflow process. Try to "vibrate" or shake the board and you can see there is not enough action to skew parts (if solderpaste has the right process window). Even if you place the board on a vibrator or mechanical shaker of several Hertz or tenths of Hertz (I work with accelerometers) the force is not enough to skew components placed over solderpaste. Then, try to bump with your fingers the board. A small bump with your fingers (but with moderate impact) will be enough to skew some parts.

So I believe that the skew is generated with a bump that can be originated with the conveyor mechanism (it can be located anywhere, do your inspection and suspect of everything that moves, rotates, etc. )

For the accelerometer idea, you could try and you have a 50/50 chance to detect the cause of skew, vibration or bumps. If the skew occurs with the oven running in cold then you will be lucky, but if for some obscure reason, the skew is only performed with the oven heating, the accelerometer procedure will be risky because all the devices in the market (force-balanced technologies and even semiconductor MEMS technology accelerometers) will not perform over junction temperature.

If you are in a hurry, or just for sake of curiosity, you could run the oven cold and place a smartphone in it with some accelerometer app running and logging XYZ activity, to see if you can detect the faulty bump(s) that is is causing skew.