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Wave Pre-heater not working

Views: 2215

#50675

Wave Pre-heater not working | 15 June, 2007

I by all means, am not an expert on Wave processes. But, our second bottom side zone for our wave is down. My boss said "well the flux looks okay, just run it" and won't give me the machine to properly fix. How many people have a problem with this? What are the long term problems that I could see as a result of not having the preheater working. I know more than likely the flux isn't being properly activated.

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#50688

Wave Pre-heater not working | 15 June, 2007

Hi Ed,
It all depends on more info needed. How many preheaers do you have in your wave? One, two, three? Are you talking bottom side preheat? What size boards do you run and what type of parts are on it.

Typically, preheat does several things; warms parts up to avoid thermal shock when going over the wave, activate the flux, avoid thermal mass, etc. If you can do this the remaining preheaters, no problem.

Personally I would reprofile the wave without the preheater to see if it meets your original criteria. Or I would avoid the whole thing like the plaque because you say you are not the expert and boss says all is well. Why step on toes? If the product comes back for thermally shocked parts or cold solder - just make sure you have on record that the boss said everything was OK.

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#50689

Wave Pre-heater not working | 15 June, 2007

I do want to run a profile, but they won't give up the machine long enough for me to run one.

The boards that we are running through the wave are large boards, with large caps, and large transformers on it. We're building highend power amps that are realitivly heavy and bulky.

There are a total of 4 preheaters on this machine. The one that is out is the second bottom one next to the wave. The top pre-heater are "heavy duty" and have a convention fan, this was a modification to the machine from the vendor because of the denisty of our products.

I want to run a profile, but they won't give me the machine long enough to run it. we have the pre-heater that needs replacement and at this point by the time it would take me to run the profile we could just have the actual problem fixed.

My boss said "Well, it looks good to me". But, what are the things we're not going to see or that will haunt us later?

Maybe I am being just a little more concerned that I need to be. In Reflow, if we loose one of twenty heaters the machine is down.

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#50692

Wave Pre-heater not working | 15 June, 2007

> I do want to run a profile, but they won't give
> up the machine long enough for me to run one.
> The boards that we are running through the wave
> are large boards, with large caps, and large
> transformers on it. We're building highend power
> amps that are realitivly heavy and
> bulky.
>
> There are a total of 4 preheaters on
> this machine. The one that is out is the second
> bottom one next to the wave. The top pre-heater
> are "heavy duty" and have a convention fan, this
> was a modification to the machine from the vendor
> because of the denisty of our products.
>
> I want
> to run a profile, but they won't give me the
> machine long enough to run it. we have the
> pre-heater that needs replacement and at this
> point by the time it would take me to run the
> profile we could just have the actual problem
> fixed.
>
> My boss said "Well, it looks good to
> me". But, what are the things we're not going to
> see or that will haunt us later?
>
> Maybe I am
> being just a little more concerned that I need to
> be. In Reflow, if we loose one of twenty heaters
> the machine is down.

> I do want to run a profile, but they won't give
> up the machine long enough for me to run one.
> The boards that we are running through the wave
> are large boards, with large caps, and large
> transformers on it. We're building highend power
> amps that are realitivly heavy and
> bulky.
>
> There are a total of 4 preheaters on
> this machine. The one that is out is the second
> bottom one next to the wave. The top pre-heater
> are "heavy duty" and have a convention fan, this
> was a modification to the machine from the vendor
> because of the denisty of our products.
>
> I want
> to run a profile, but they won't give me the
> machine long enough to run it. we have the
> pre-heater that needs replacement and at this
> point by the time it would take me to run the
> profile we could just have the actual problem
> fixed.
>
> My boss said "Well, it looks good to
> me". But, what are the things we're not going to
> see or that will haunt us later?
>
> Maybe I am
> being just a little more concerned that I need to
> be. In Reflow, if we loose one of twenty heaters
> the machine is down.

Well when in prevent mode at the wave like this, your best option is to slow the conveyor speed down a bit. Maybe 15 to 20 percent. This should work and you should be OK.

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