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Right angle PTH lead profile = blowholes

Views: 1937

#53229

Right angle PTH lead profile = blowholes | 16 January, 2008

We've got an auto fuse clip (a pair of tin/nickle spade type receptacles joined with a nylon bridge piece) giving us fits.

The pins on this thing have a right angle profile (symmetrical "L" shape) and make great flux traps. No amount of tweaking preheat, conveyor speed, or flux volumes have provided any resolution w/o creating bigger problems. We're going to look at angling the fluxer air knife a little and orienting the boards to provide a little shadowing but I don't have much hope for it.

For what it's worth, here's a link to the spec.

http://www.keyelco.com/products/specs/spec92.asp

Any ideas?

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#53246

Right angle PTH lead profile = blowholes | 17 January, 2008

Have you tried waving the board rotated 90* from the normal orientation?

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#53250

Right angle PTH lead profile = blowholes | 18 January, 2008

Try lifting the part with a small piece of paper. I've seen caps that did this and giving the flux a way to vent out the top side of the board got rid of the blow holes. It'll take ya 2 seconds to to try - that plus the 3 minutes to wave solder.

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#53266

Right angle PTH lead profile = blowholes | 19 January, 2008

Dave that's actually what I want to work on the next time we run these. Our issue with these right now is that weight distribution on the boards mandates that we break a 4-up panel into two pieces and run it 90 degrees to the ideal orientation (=s what you're suggesting). I want to add a stiffener and run the full panel. We might angle the fluxer a little also but it's not something I want to putz with every time we run that board.

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#53267

Right angle PTH lead profile = blowholes | 19 January, 2008

That's a good idea. We did pull the bridge piece off of one just to see what happens with the receptacles only, so no flux blockage. They flowed great with no blowholes, but also filled with solder. :/

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