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Component Failure caused by Hot Air Knife

#2975

Component Failure caused by Hot Air Knife | 20 September, 2000

We are considering retrofitting our Vectra wave soldering machine with a hot air knife. I've run our problem board on a machine with this option and it does seem to work; however, there is a concern of component failure due to thermal shock. Is this a valid concern on a properly setup knife? I looked in the archives but didn't see a posting on this aspect of the process.

Thanks in advance John

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jackofalltrades

#2976

Re: Component Failure caused by Hot Air Knife | 20 September, 2000

On the Vitronics/Soltec Wave Soldering Machines, we have no problems with the hot air knife (called a "Select X De-Bridging Tool" by Vitronics). We have both Delta's and Delta Max's. We have used both air and nitrogen with no problems. When using a "Mole" to check the thermal profiles there was very little increase in temp and still well within desired parameters. As you mentioned though it still needs to be properly set-up. And by the way, our first air knife was also a retrofit, now we automatically but with it installed.

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Boca

#2977

Re: Component Failure caused by Hot Air Knife | 21 September, 2000

We have been using a hot air knife on Electrovert equipment for a few years. It must be set up properly for a given machine, primarily the distance from the trailing edge of the wave. Sometimes the set up must be adjusted for the assembly being soldered. Usually just temperature and angle adjustments.

The hot air knife is a tool for defect reduction, not a 'fix all' solution to poor fab design. With skillful use, defects can usually be reduced, often not eliminated.

We have never had any component failure issues related the the hot air knife.

Boca

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