I think some people are likely to respond that we are still in the days of
vapour phase...to avoid a diversion
lets just say when first implemented vapour phase machines had two vapour
layers. The primary layer was the Fluorinert which did all the work.
Fluorinert was very expensive so to reduce losses a secondary (sacrificial)
layer of Freon was floated over it. The Freon certainly did tend to break
down to acid and much engineering effort [and even more sales] spent in
keeping the two layers in their respective places, making the machines acid
proof, filters etc. The acid was ordinary hydrochloric (HCL).
Fluorinert could be broken down and there was some evidence of a toxic
chemical being produced, at this distance in time I can't remember what it
was called but so far as I know this was a theoretical risk only. The chance
of it getting out of the machine (and therefore the actual hazard) was tiny.
I would be surprised if hydrofluoric acid was generated and even more
surprised if it accumulated as it would immediately react with just about
anything handy. Better chemists than I will no doubt address this issue
also.


Best regards

Mike Fenner
Applications Engineer, European Operations
Indium Corporation
 T: + 44 1908 580 400
M: + 44 7810 526 317
 F: + 44 1908 580 411
 E: [log in to unmask]
W: www.indium.com
Leadfree: http://Pb-Free.com



-----Original Message-----
From: TechNet [mailto:[log in to unmask]]On Behalf Of Marsico, James
Sent: Monday, October 15, 2001 5:49 PM
To: [log in to unmask]
Subject: [TN] Vapor Phase Soldering material


Back in the days of vapor phase soldering, I seem to recall that
hydrofluoric acid was a bi-product of the fluorinert mixed with water, or
was it the Freon mixed with the fluorinert?   Could anyone elaborate?

Jim Marsico
Senior Engineer
Production Engineering
EDO Electronics Systems Group
[log in to unmask] <mailto:[log in to unmask]>
631-595-5879

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