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Flux Packages

BLNorman

#5104

Flux Packages | 31 January, 2001

I listed this under design, but got no responses, so I'll try this forum.

Our current solder paste vendor wants us to evaluate a paste. One of the selling points is that this paste (SnPb) will have the same flux package that will be used with some of their lead-free pastes. We are looking at going to SAC when we go lead-free, so I'm wondering if a flux package is compatible with both, or are they blowing smoke up our... Anybody have any experience or insight?

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#5114

Flux Packages | 31 January, 2001

I�ve seen this chatter about "fully compatible with families of alloys" in the trade journals and never really thought about it, until you posted. [You know, stay focused, don�t get distracted by what�s going on out there, and all that stuff.] Then, after you posted, I thought "Who cares? I mean you just wash the flux residues, anywho. So, what are these people talking about?" Then DING!!! Like the mid-day sun appearing over the edge of the Fresh Kill Landfill, it dawned on me that the people that care about this drivel are NC people. Cool, eh? See, I�m not a dinosaur. [Yeh, sure]

Well now BL, you can see where this is going and probably the best course of action for you is to hit BACK.

It�s possible, but unlikely that one flux will stay active over the ~220�C to ~255�C range necessary to reflow the two alloys, not get crispy too fast, not generate a bazillion voids, and adapt to the different wetting properties of the alloys. And it would be very nice, too.

Now if Dr. Ning-Cheng Lee [or someone like him] made this flux announcement, I�d bite. I hate to cast aspersions on salestypes, because I�ve heard there has been times when they don�t lie, BUT yano what Uncle Sammy used to say? "The proof is in the pudding!" If this isn�t vaporflux, then they should be able to demonstrate minuscule innocuous residues, zero voids, and well formed connections using both materials after soldering a couple of your boards.

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Boca

#5163

Flux Packages | 7 February, 2001

I wasn't 'getting it' either.

Oh what a tangled web we weave when we practice to .... go no clean.

Thanks Dave!

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