Vapour phase Soldering

[mrpackethead]

What do you make of the "cover zone" layer that they show in their machine?   Thats got me a bit confused.

[mrpackethead]

One of the distributors is Hawker richardson in .au   

[mrpackethead]

wonder if their is a cheap chinese knock off  that is like garden LS230

[mrpackethead]

ok, 5kg is $AUD1420+GST.   that is 2750ml or so.

Anyone keen to split this up?     Suggest 5 segments of 500ml ( allowing a wee bit of of wiggle room for any waste when repackaging )

That would be $284 for 500ml, ( 905g ) + Courier, Ex Melbourne.


I'll take 1kg to start, things off, so just need three others.

[jeremy]

I'm up for some. PM sent.

[mrpackethead]

That wenesco machine seems to have a two zone system. I'm wondering, if they use two different fluids..    If you stuck two different fluids in the same container, and heated them, would you get two different vapour zones?   one one top of the other?   

[jeremy]

That wenesco machine seems to have a two zone system. I'm wondering, if they use two different fluids..    If you stuck two different fluids in the same container, and heated them, would you get two different vapour zones?   one one top of the other?

In my research I found that people used to use two layers to increase the vapour retention and decrease the thermal gradient for the board. Galden SVP is the second fluid name, where svp stands for Soft Vapour Phase. See: http://amtest.bg/products/Asscon/Galden%20PFPE%20Fluids%20Data%20Sheet.pdf

I also found that this has been somewhat phased out. Not sure why though.

[Kjelt]

Thinking about the heating element/system.

If you look at pro kitchen equipment, they only place a heater under the stainless steel container for temperatures up to 90 degrees C (like warmwater baths, bain marie).
Above those temperatures like in frying equipment (180 to 200 degrees C typically) they place the heating element inside the stainless steel container making contact with the fluid.

So would it be allowed for this vapour chemical to be in direct contact with the heating element or would that not be advised?

[jeremy]

Thinking about the heating element/system.

If you look at pro kitchen equipment, they only place a heater under the stainless steel container for temperatures up to 90 degrees C (like warmwater baths, bain marie).
Above those temperatures like in frying equipment (180 to 200 degrees C typically) they place the heating element inside the stainless steel container making contact with the fluid.

So would it be allowed for this vapour chemical to be in direct contact with the heating element or would that not be advised?

Perfluorocarbons decompose into fluorine gas and HF, and the MSDS for galden lists >290 as the decomposition temp. However, before that temp, this class of chemicals are one of the most inert chemicals know to mankind (http://www.epa.gov/chemrtk/pubs/summaries/perfluro/c13244rt3.pdf). So I don't think there is any problem having direct contact, as long as your element doesn't go over 290C. I was thinking of just using some sort of iron core element and putting a thermocouple in there.

Also, this: http://www.ebay.com.au/itm/MULTICORE-SOLDERS-VAPORETTE-/111436980268 which was an early commercial system, used external heating. But no temp control?

I am not a chemist though, ymmv, etc.

[mrpackethead]

In my research I found that people used to use two layers to increase the vapour retention and decrease the thermal gradient for the board. Galden SVP is the second fluid name, where svp stands for Soft Vapour Phase. See: http://amtest.bg/products/Asscon/Galden%20PFPE%20Fluids%20Data%20Sheet.pdf
I also found that this has been somewhat phased out. Not sure why though.

I found that link as well, but it seems its disappeared as well.     It would be interesting to know why they don't use it.

[mrpackethead]

Thinking about the heating element/system.

If you look at pro kitchen equipment, they only place a heater under the stainless steel container for temperatures up to 90 degrees C (like warmwater baths, bain marie).
Above those temperatures like in frying equipment (180 to 200 degrees C typically) they place the heating element inside the stainless steel container making contact with the fluid.

So would it be allowed for this vapour chemical to be in direct contact with the heating element or would that not be advised?

My concern with having the heater in the tank is not to do with contaimination, its to do with the amount of fluid you'll need in your tank to cover the element.  In my home deep fryer, i'll need 3.5l minimum to cover it.  and when we heat it, and evaporate it, we'll have even less covering the elements.  they will just overheat.     That machine that we were looking at before claims it will work with just 1 quart ( ~1 litre ).     By having external heating it will be much easer to avoid this issue.

Deepfryer is off the list of suitable things to use..  I'm also thinking we want to make it a *lot* deeper than your average deep fryer.

So, excuse the very bad pun.

"Deep fryer is for making chips, not soldering them"

[Kjelt]

Deepfryer is off the list of suitable things to use

It was never my intention to advise to use a deepfryer, I was merely saying that if you look at pro kitchen equipment that heats a bath above 100^oC they do not put the heating element below and against the bottom of a stainless steel container anymore. Now there has to be some reason for that?
I can think for instance that it is not safe to use a heater that way with such high temperatures since it will radiate in all directions so the whole area will have that temperature so the electrical wiring etc has to withstand that temperature. So heating from below with a standard heating element is probably not an option. Thats all I was trying to say.
Than I would indeed rather use the induction method FreeElectron has given.
You need a temperature of 230^oC for the leaded solderpaste and a bit above that for the unleaded, so these are quite high fluid temperatures.

[jeremy]

You're right Kjelt, but I think I would rather have something made of pyrex so I can see inside. I'm currently liking the idea of using induction and putting a chunk of iron inside the vessel.

edit: Although the recommended reflow temperature for SN100C with vapour phase is 230C - 245C from here

[free_electron]

free_electron: nice pic. what did you draw it in?

Altium silkscreen layer 

[free_electron]

Thinking about the heating element/system.

If you look at pro kitchen equipment, they only place a heater under the stainless steel container for temperatures up to 90 degrees C (like warmwater baths, bain marie).
Above those temperatures like in frying equipment (180 to 200 degrees C typically) they place the heating element inside the stainless steel container making contact with the fluid.

So would it be allowed for this vapour chemical to be in direct contact with the heating element or would that not be advised?

My concern with having the heater in the tank is not to do with contaimination, its to do with the amount of fluid you'll need in your tank to cover the element.  In my home deep fryer, i'll need 3.5l minimum to cover it.  and when we heat it, and evaporate it, we'll have even less covering the elements.  they will just overheat.     That machine that we were looking at before claims it will work with just 1 quart ( ~1 litre ).     By having external heating it will be much easer to avoid this issue.

Deepfryer is off the list of suitable things to use..  I'm also thinking we want to make it a *lot* deeper than your average deep fryer.

So, excuse the very bad pun.

"Deep fryer is for making chips, not soldering them"

like i said. get a turkey fryer. those are really deep.
throw a iron metal plate inside the fryer at the bottom. ( turkey fryers are aluminium ... )
put fryer on induction heater.

should work ...

[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]

free_electron: nice pic. what did you draw it in?

Altium silkscreen layer 

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]

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?

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.

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.

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.

[mrpackethead]

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.

Im with you on this conclusion now.  and maybe even you get a mixture of different chain lengths, which average out to give you a specific temp?

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.

HT and LS grades are avaialable over the same range of BP's..  You can get LS230 and HT230.. Both have a nomial boiling point of 230C.   Theres LS200 ( which would be good for lead solder i guess ) and an HT200.

I have two suspicions.   

(a) the product may in fact be the same thing marketed at two different products, for two different end uses.. one has a higher price tolerance than the other
(b) the LS product is 'refined' more accurately than the HT, so the actual BP, may be sitting in a smaller range than the HT.

I've seen quite a number of commercial machines specifying HT grade, and the DIY projects we've seen all seem to use HT.   

Its less than half the price..   If we have a temp range that is just a wee bit wider, does it actually matter, provided its not too far out?

[helius]

perfluoroalkylamines like Fluorinert were used as blood substitutes because of their ability to dissolve oxygen. This is not desirable for soldering because oxygen reacts with the metals, making a duller joint that wets more poorly.

[jeremy]

Thanks Luke for the tips. I agree, after reading the patents they seem to just make a big batch of perfluorinated polyethers of varying chain lengths (get polyethers, add fluorine, bake at 180C until golden brown, etc) then distill it into the different boiling points. It's interesting that HT is so much cheaper, and potentially not necessary for vapour phase. If weller recommends HT, I trust them with all my other soldering gear, so I don't see a problem.

It's kind of strange that the other manufacturers use LS actually...

I found a guy in australia who sells quite large diameter and length borosilicate tubes. Also, you can get a 4L beaker with a ~160mm ID on Amazon for not too much. This plus a stainless "induction interface disk" (google it) seems like it could be a decent way to start. Now I'm trying to think about how to raise the board gently when potentially the balls are still liquid. Or perhaps since it is a hobby system and I only need one board, just turn off the heating and wait for it to cool. Suggestions welcome!

Edit: I was also thinking about just putting some ball bearings in the bottom of the beaker. What do you all think? Galden has basically no chance of exploding, so I can't see a problem there.

[free_electron]

free_electron: nice pic. what did you draw it in?

Altium silkscreen layer 

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...!

Altium pcb has almost everything regular 2d cad has. Corrdinate system, multip,e layers , lines arcs polygons , you can place dimensions , rotate stuff, there is a library system for often used symbols. You can load and save dxf to be compatible with the rest of the world.
And you dont have to learn some awkward tool. Works perfectly fine for me !

[langwadt]

free_electron: nice pic. what did you draw it in?

Altium silkscreen layer 

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...!

I've done it but now I use http://www.plm.automation.siemens.com/en_gb/products/solid-edge/free2d/

free and extremely easy to use