Hot Air Nife

Anyone using hot air nife for wave soldering process. Does it work? Does it really eliminate solder bridging and does it create any other problems?

any feed back will be much appriciated.

Thanks

Tony A

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| Anyone using hot air nife for wave soldering process. | Does it work? | Does it really eliminate solder bridging and does it create any other problems? | | any feed back will be much appriciated. | | Thanks | | Tony A | | I have a article I produced on the use of the air knife that I can email if you like. I have used a knife and it can solve problems on poor designs.

Bob Willis

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| Anyone using hot air nife for wave soldering process. | Does it work? | Does it really eliminate solder bridging and does it create any other problems? | | any feed back will be much appriciated. | | Thanks | | Tony A | | I have a article I produced on the use of the air knife that I can email if you like. I have used a knife and it can solve problems on poor designs.

Bob Willis

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| | Anyone using hot air nife for wave soldering process. | | Does it work? | | Does it really eliminate solder bridging and does it create any other problems? | | | | any feed back will be much appriciated. | | | | Thanks | | | | Tony A | | | | I have a article I produced on the use of the air knife that I can email if you like. I have used a knife and it can solve problems on poor designs. | | Bob Willis | | | Tony,

Done some work with a hot nitrogen knife..basically the same thing although this one is a selective one that you program to specific spot's. It's not bad and can get rid of short's once you get the setting's right up to a point. It only work's of there is across the way i.e. with any great success up and down is harder since you run into cascading effect's. It can also generate some problems, if it's set at too high a pressure then it can blow the solder from some smaller joint's or cause solder splatters on the boards but it's all a mater of control, the best way of using it is to hone the process first then use it as a last resort, the danger with these thing's is that you end of using them to cover up a poor process rather than helping with poor designs..

all the best

John

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| Anyone using hot air nife for wave soldering process. | Does it work? | Does it really eliminate solder bridging and does it create any other problems? | | any feed back will be much appriciated. | | Thanks | | Tony A

Hi Tony

I have bought and used the Electrovert hot nitrogen air knife to desolder bridges on 50 mil SOICs. It works very well, but is very noisey. If your plant is a quite one, this thing will gather attention. The bottom line, it does work. Make sure you get one that can adjust easy too. I'm not sure what model your looking at. | |

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| | Anyone using hot air nife for wave soldering process. | | Does it work? | | Does it really eliminate solder bridging and does it create any other problems? | | | | any feed back will be much appriciated. | | | | Thanks | | | | Tony A | | | | I have a article I produced on the use of the air knife that I can email if you like. I have used a knife and it can solve problems on poor designs. | | Bob Willis | | Bob/John,

Thanks for replying so fast to my needs. I feel great knowing that it could help on poor desing assemblies.

I am trying to prepare a justification to have a hot air nife added to our current Dover Wave Solder Machine.

our machine is not that old and hot air nife was not available when we purschase the machine.

BOB can you e-mail me your article.

Thanks again BOB and John

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| | Anyone using hot air nife for wave soldering process. | | Does it work? | | Does it really eliminate solder bridging and does it create any other problems? | | | | any feed back will be much appriciated. | | | | Thanks | | | | Tony A | | | | I have a article I produced on the use of the air knife that I can email if you like. I have used a knife and it can solve problems on poor designs. | | Bob Willis | Bob: Why don't you publish this in SMTnet papers? I'm sure many would be interested in reading it. You have written many of the papers have written have broad interest. Thanks. Dave F

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| Anyone using hot air nife for wave soldering process. | Does it work? | Does it really eliminate solder bridging and does it create any other problems? | | any feed back will be much appriciated. | | Thanks | | Tony A | | Tony,

The hot knife is a great invention. It opens up the window for both the process and the design. Now, in a perfect world, board designs would not violate keepout zones between pads & pads and pads & vias, nor would the leads be closer than 100 mil centers, the leads would be trimmed to the perfect length, and SOIC's would have theive pads on all trailing sides. By the same token, all operators would be conscientious enough to set perfect wave heights and maintain proper nozzle setups to get perfect peel offs. And all fluxes would have powerful surfactants and high thermal stability to act like the 310B and help eliminate bridges before they form.

Reality Check! Designs aren't perfect, neither are the humans, and very often we have to work with what we are given. WHich brings me to the hot air knife. It is the great forgiver. It "blows away" those design issues, and if you're wave setup ain't quite optimal, you're covered there, too.

It's a powerful tool. But if you don't use it right, it can get you into lots of trouble by blowing solder into places you don't want it to go - like up through holes and onto the top of the board, all over the inside of the machine, or out the load end onto operators.

My best results with the hot knife are running it at high temperatures and low pressures. The high temp (set at 800 F at the heater, about 650F at the delivery to the board) keeps the solder warm and at low viscosity while the pressure breaks the bridges. The low pressure (aroud 5 psi) means a low velocity of the air (or nitrogen) stream, which successfully debridges without making a mess of things.

One note on the knife - in inerted systems like the Electrovert contour, the knife entrains a good amount of air, and your soldering atmosphere's purity can decrease to only 95% nitrogen. This means more dross, but studies I've done show no sizable impacts on solderability or joint quality.

I'll post a Nepcon paper to the library on the effects of the hot knife on the soldering environment.

Chrys

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| | Anyone using hot air nife for wave soldering process. | | Does it work? | | Does it really eliminate solder bridging and does it create any other problems? | | | | any feed back will be much appriciated. | | | | Thanks | | | | Tony A | | | | | Tony, | | The hot knife is a great invention. It opens up the window for both the process and the design. Now, in a perfect world, board designs would not violate keepout zones between pads & pads and pads & vias, nor would the leads be closer than 100 mil centers, the leads would be trimmed to the perfect length, and SOIC's would have theive pads on all trailing sides. By the same token, all operators would be conscientious enough to set perfect wave heights and maintain proper nozzle setups to get perfect peel offs. And all fluxes would have powerful surfactants and high thermal stability to act like the 310B and help eliminate bridges before they form. | | Reality Check! Designs aren't perfect, neither are the humans, and very often we have to work with what we are given. WHich brings me to the hot air knife. It is the great forgiver. It "blows away" those design issues, and if you're wave setup ain't quite optimal, you're covered there, too. | | It's a powerful tool. But if you don't use it right, it can get you into lots of trouble by blowing solder into places you don't want it to go - like up through holes and onto the top of the board, all over the inside of the machine, or out the load end onto operators. | | My best results with the hot knife are running it at high temperatures and low pressures. The high temp (set at 800 F at the heater, about 650F at the delivery to the board) keeps the solder warm and at low viscosity while the pressure breaks the bridges. The low pressure (aroud 5 psi) means a low velocity of the air (or nitrogen) stream, which successfully debridges without making a mess of things. | | One note on the knife - in inerted systems like the Electrovert contour, the knife entrains a good amount of air, and your soldering atmosphere's purity can decrease to only 95% nitrogen. This means more dross, but studies I've done show no sizable impacts on solderability or joint quality. | | I'll post a Nepcon paper to the library on the effects of the hot knife on the soldering environment. | | Chrys | | This is really great information.

Not only I have learned more about Hot Air Knife, but I have also learn how to SPELL HOT AIR KNIFE..LOL

COOL

Thank YOU ALL for the info.

Tony A

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| | | Anyone using hot air nife for wave soldering process. | | | Does it work? | | | Does it really eliminate solder bridging and does it create any other problems? | | | | | | any feed back will be much appriciated. | | | | | | Thanks | | | | | | Tony A | | | | | | I have a article I produced on the use of the air knife that I can email if you like. I have used a knife and it can solve problems on poor designs. | | | | Bob Willis | | | | | Bob/John, | | Thanks for replying so fast to my needs. | I feel great knowing that it could help on poor desing assemblies. | | I am trying to prepare a justification to have a hot air nife added to our current Dover Wave Solder Machine. | | our machine is not that old and hot air nife was not available when we purschase the machine. | | BOB can you e-mail me your article. | | Thanks again BOB and John | Tony,

A word of warning about retrofitting the air / nitrogen knife to the machine, we did it to a soltec Deltawave, work's great but we had to steal / borrow the supply from the nitrogen cover for the wave..we've had a little extra dross but the machines working most of the time so it's not that big a deal. but make sure you aint gonna rob peter to pay paul

John

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| Why don't you publish this in SMTnet papers? I'm sure many would be interested in reading it. You have written many of the papers have written have broad interest. Thanks. Dave F

Dave: Thank you for the suggestion.

Bob: We would very much like to include your papers in the SMTnet Library. It is set up for all to post items directly after completing a basic registration (either as a company or individual). We will be glad to post papers for you too, if you send us the files along with a 50-word summary of each.

Thanks.

Cunli

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