Electronics > Projects, Designs, and Technical Stuff
Vapour phase Soldering
mrpackethead:
Instructions for Weller machine.
http://www.egmont.com.pl/cooper/instrukcje/OI_WAM3000_GB.pdf
They use the HT Fluid, along with a couple of others. Having talked with one of the suppliers, the difference between the LS and the HT, is the tolerance of the boiling point. The HT, is not as precise as the LS, but its also less than half the price. $121/kg vs $270/kg.
The beaker based project used HT, Weller are using HT, and if you are prepared to accept a small ( maybe 5 degrees ) difference vs 1 degree variation in boiling point, ( i'm asking for clarificaiton of this point ), then HT might be well acceptable.
The Weller machine only requires 1 litre of fluid as well.
I'm tending to be thinking that for my application HT might be just fine..
mikeselectricstuff:
--- Quote from: free_electron on January 23, 2015, 05:42:46 pm ---
--- Quote from: jeremy on January 22, 2015, 08:53:12 am ---free_electron: nice pic. what did you draw it in?
--- End quote ---
Altium silkscreen layer >:D
--- End quote ---
So I'm not the only one that does drawings in PCB software because I can't be arsed to learn a proper CAD package then...!
IconicPCB:
This ebay offer is very expensive for what is on offer.
A new Wenesco of similar construction and technological approach, NEW and under warranty is USD5500.--
NO LINKS TO WENESCO other than common sense.
helius:
The seller doesn't really expect to get $5k, that is an optimistic estimate for negotiation's sake.
The problem is that a machine of that vintage may not be designed for the same parameters as is used today. It says it uses a type of Fluorinert, but not what solder alloy it expects. Not a RoHS solder, anyway.
LukeW:
--- Quote from: jeremy on January 20, 2015, 08:19:37 pm ---Interesting, it's not LS230 but HT230. Both have the same CAS numbers and structural formulae. Anyone know a chemist who can shed some light on this?
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It looks like the Galden LS series is a mixture of perfluorinated polyethers of varying chain length, varying molecular weight in the 700-1000 range, it's not just one chemical.
So, basically, they can just separate it into whatever boiling-point range is desired by fractional distillation, just like distillation of hydrocarbons at an oil refinery.
http://www.solderconnection.com/specsheets/Galden_LS_-_MSDS.pdf
Galden HT seems to be similar but with a higher BP range, higher than soldering will need, targeted as a chemically-stable coolant for specialist applications, eg. CVD, ion implanters, plasma etching and stuff at applicable apparatus temperatures, especially where chemicals or reagents are involved that may react with a non-perfluoro coolant (uranium enrichment, for example, is one application they mention). The chemical formula is the same, but the typical length of the polymer, the average "m" and "n" numbers in the formula, will be higher. And the CAS number is the same because it's the same general family of chemicals with one CAS number as a group.
--- Quote from: helius on January 21, 2015, 09:11:08 pm ---in the video from 3M, they are doing selective soldering using a low melting point alloy for attaching heat sinks. So they need to use a fluid with a boiling point between the melting point of their solder (140° C) and the solder in the processor package (probably SAC305: 217° C). The Fluorinert FC-40 has a bp of 155° C, so it is perfect in this application. Galden fluids have a boiling point of 230° C because they are designed for primary soldering.
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There are a whole series of different chemicals (and mixtures) under the Fluorinert brand, just like there are under the Galden brand.
Fluorinert FC-70 is perfluorotripentylamine, for example, and any perfluorotripentylamine from any vendor is identical to FC-70 from 3M.
FC-40 is a combination of two compounds - perfluorotributylamine and perfluorodibutylmethylamine - but overall its composition is less complicated than the complex-mixture Galden fluids. Also these ones are perfluorinated trialkylamines, not ether polymers, but they're still perfluorinated, they're still really inert, and their basic properties are somewhat the same.
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